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README.md
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191
README.md
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# synplexum
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End to end framework for compiling tensor programs. Splits the program into abstraction layers, relies on automated tools for verification and optimization. Allows the programmer full control of the execution, down to ASM and GPU instruction graphs, without weighing them down with implementation details.
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## quickstart
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Read the `spec.md` and other `*_demo.md` files in the root to understand the scope of the project.
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We have a L1 DSL specifying actors and leafs over a data pipeline. These are primitives meant for dealing with moving data over a CPU or network. To interact, run the repl:
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```bash
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cargo run -- repl
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```
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Then type `:help` for usage guidelines, and `:examples` to see some prebuilt usage.
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### demo output
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```
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L1 REPL — type declarations or :help for commands.
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l1> :help
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L1 REPL Commands
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────────────────
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:load <file> Load a .l1 file, replacing current state
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:reset Clear all declarations
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:run [N] Compile and execute (N overrides step count)
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:ir Show current L1 IR with pipeline diagram
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:l0 Show emitted L0 IR (syntax-highlighted)
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:verify Run formal verification pipeline
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:run-verified Run with all invariant checks and produce verified report
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:help Show this help and DSL reference
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:examples List built-in examples
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:examples <name> Load example with annotated walkthrough
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:quit Exit the REPL
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Declaration Forms
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─────────────────
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actor <name> {
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state { <field>: <type> = <init>, ... }
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Mutable fields owned by this actor. Updated in handlers.
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window <name> : (<field>, ...) readers(<leaf>, ...)
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Read-only snapshot of selected fields. Leaves listed in
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readers() may read this window. Provides safe concurrent access.
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on <MessageType>(<arg>: <type>, ...) { <body> }
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Message handler. Body is a sequence of field assignments.
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Expressions: field refs, args, literals, arithmetic (+, -, *).
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}
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leaf <name> {
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reads <actor>.<window>
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(optional) Declares which actor window this leaf may read.
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process {
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forward(<actor>, <MsgType>(<arg>, ...))
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Send a message to an actor's handler.
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read(<actor>.<window>.<field>)
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Read a field from a window snapshot.
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emit(<expr>)
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Emit a value to the output region (observable output).
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}
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}
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pipeline <name> { <stage> -> <stage> -> ... }
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Defines execution order. Stages are actor or leaf names.
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Each core step walks the pipeline left to right.
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core <name> {
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actors: [<name>, ...] Actors in this core
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leaves: [<name>, ...] Leaves in this core
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pipelines: [<name>, ...] Pipelines to execute
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steps: <N> Number of execution steps (bounded)
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}
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Types & Expressions
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───────────────────
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Field types: u64, i64, f64
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Operators: + - * (binary arithmetic)
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Literals: 0, 1, 42, ... (unsigned integers)
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Expressions: field, arg, literal, (expr op expr)
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Execution Semantics
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───────────────────
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Each core step:
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1. Walk pipeline stages left to right
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2. Leaves execute: forward messages, read windows, emit outputs
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3. Messages dispatched to actor handlers, updating state
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4. Window snapshots updated for next step
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Execution is bounded (finite steps) — no unbounded loops.
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Multi-line input: open braces auto-continue to the next line.
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```
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built in example:
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```
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l1> :examples counter
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Example: counter
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─────────────────
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┌─ The simplest L1 program. One actor receives Increment messages
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│ and counts up. A leaf sends the message each step.
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actor counter {
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state {
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count: u64 = 0
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}
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▲ One mutable field: count, starts at 0.
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window count_view : (count) readers(display)
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▲ Exposes 'count' as a read-only window. The 'display' leaf
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can read it safely without blocking the actor.
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on Increment(amount: u64) {
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count = count + amount
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}
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▲ Handler: when an Increment(amount) message arrives,
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add amount to count. This is the only way state changes.
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}
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leaf ticker {
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process {
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forward(counter, Increment(1))
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}
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}
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▲ Each step, ticker sends Increment(1) to counter.
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Leaves are the edges of the system — they produce and consume.
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leaf display {
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reads counter.count_view
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process {
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read(counter.count_view.count)
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}
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}
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▲ display reads the count window. 'reads' declares the dependency;
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read() in process actually fetches the value.
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pipeline main { ticker -> counter -> display }
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▲ Execution order: ticker sends, counter processes, display reads.
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core main {
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actors: [counter] leaves: [ticker, display]
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pipelines: [main] steps: 5
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}
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▲ Runs the pipeline for 5 steps. After: count = 5.
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Execution is bounded — no infinite loops possible.
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Try: :run to execute, :ir for IR, :verify for formal verification
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l1> :ir
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L1 IR
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─────
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actor counter {
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state {
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count: u64 = 0
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}
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window count_view : (count) readers(display)
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on Increment(amount: u64) { count = (count + amount) }
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}
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leaf ticker { forward(counter, Increment(1)); }
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leaf display { reads counter.count_view; read(counter.count_view.count); }
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pipeline main { ticker -> counter -> display }
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core main {
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actors: [counter]
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leaves: [ticker, display]
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pipelines: [main]
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steps: 5
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}
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Pipeline Topology
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─────────────────
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pipeline: main
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[ leaf: ticker ]
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forward -> counter.Increment
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│ Increment
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▼
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┌─ actor: counter ─┐
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│ state: {count: u64} │
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│ window: count_view (count) │
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│ on Increment(amount: u64) │
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└──────────────┘
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│
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▼
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[ leaf: display ]
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read counter.count_view.count
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core: main
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actors: [counter] leaves: [ticker, display] steps: 5
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```
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965
formal_verification_demo.html
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965
formal_verification_demo.html
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<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="utf-8">
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<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=5.0">
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<title>Formal Verification Pipeline: Proving L1→L0 Lowering Correctness</title>
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<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/themes/prism-tomorrow.min.css">
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<style>
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:root {
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--bg: #1a1a2e;
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--bg-code: #16213e;
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--bg-inline: #0f3460;
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--fg: #e0e0e0;
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--fg-dim: #a0a0b0;
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--accent: #e94560;
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--accent2: #53a8b6;
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--border: #2a2a4a;
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--table-stripe: #1e1e3a;
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--pass: #4ec9b0;
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--fail: #e94560;
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}
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* { box-sizing: border-box; margin: 0; padding: 0; }
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html {
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font-size: 16px;
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-webkit-text-size-adjust: 100%;
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scroll-behavior: smooth;
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}
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body {
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font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto,
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'Helvetica Neue', Arial, sans-serif;
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background: var(--bg);
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color: var(--fg);
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line-height: 1.7;
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padding: 1rem;
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max-width: 100%;
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overflow-x: hidden;
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overflow-wrap: break-word;
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}
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article {
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max-width: 720px;
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margin: 0 auto;
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}
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h1 {
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font-size: clamp(1.3rem, 4vw, 1.6rem);
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margin: 1.5rem 0 0.8rem;
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color: var(--accent);
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line-height: 1.3;
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border-bottom: 2px solid var(--accent);
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padding-bottom: 0.4rem;
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}
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h2 {
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font-size: clamp(1.1rem, 3vw, 1.3rem);
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margin: 2rem 0 0.6rem;
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color: var(--accent2);
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border-bottom: 1px solid var(--border);
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padding-bottom: 0.3rem;
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}
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h3 {
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font-size: clamp(1rem, 2.5vw, 1.1rem);
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margin: 1.5rem 0 0.5rem;
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color: var(--fg);
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}
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p {
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margin: 0.6rem 0;
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}
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strong {
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color: var(--accent2);
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}
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a {
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color: var(--accent2);
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text-decoration: none;
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}
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/* Code blocks */
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pre {
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background: var(--bg-code);
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border: 1px solid var(--border);
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border-radius: 6px;
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padding: 0.8rem;
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margin: 0.8rem 0;
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overflow-x: auto;
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-webkit-overflow-scrolling: touch;
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font-size: clamp(0.7rem, 1.8vw, 0.82rem);
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line-height: 1.5;
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white-space: pre;
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word-wrap: normal;
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}
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/* Override Prism theme to match page palette */
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pre[class*="language-"],
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code[class*="language-"] {
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background: var(--bg-code) !important;
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text-shadow: none !important;
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}
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pre code {
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background: none !important;
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padding: 0;
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border: none;
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font-size: inherit;
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color: var(--fg);
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}
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code {
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font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Menlo',
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'Consolas', monospace;
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background: var(--bg-inline);
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padding: 0.15rem 0.35rem;
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border-radius: 3px;
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font-size: 0.88em;
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}
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/* Pipeline flow diagram */
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.pipeline {
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margin: 1.2rem 0;
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padding: 1rem;
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border: 1px solid var(--border);
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border-radius: 8px;
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background: var(--bg-code);
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}
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.pipeline-title {
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text-align: center;
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font-weight: 600;
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color: var(--accent2);
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margin-bottom: 1rem;
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font-size: 0.95rem;
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}
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.pipeline-flow {
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display: flex;
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flex-direction: column;
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align-items: center;
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}
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.pf-node {
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background: var(--bg);
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border: 1px solid var(--border);
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border-radius: 6px;
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padding: 0.45rem 1.2rem;
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text-align: center;
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font-size: 0.88rem;
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font-weight: 500;
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width: 100%;
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max-width: 14rem;
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}
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.pf-node small {
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font-size: 0.78rem;
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color: var(--fg-dim);
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font-weight: 400;
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}
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.pf-node.pf-final {
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border-color: var(--accent);
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color: var(--accent);
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}
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.pf-node.pf-pass {
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border-color: var(--pass);
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color: var(--pass);
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}
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.pf-edge {
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display: flex;
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flex-direction: column;
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align-items: center;
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padding: 0.15rem 0;
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font-size: 0.75rem;
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color: var(--fg-dim);
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font-style: italic;
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line-height: 1.2;
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}
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.pf-edge::after {
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content: '\25BC';
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color: var(--accent2);
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font-size: 0.7rem;
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font-style: normal;
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}
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.pf-gate {
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color: var(--accent);
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font-weight: 600;
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font-style: normal;
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}
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/* Verification result boxes */
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.verify-box {
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border: 1px solid var(--border);
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border-radius: 8px;
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margin: 1rem 0;
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overflow: hidden;
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}
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.verify-header {
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padding: 0.5rem 0.8rem;
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font-weight: 600;
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font-size: 0.9rem;
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display: flex;
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justify-content: space-between;
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align-items: center;
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}
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.verify-header.pass {
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background: rgba(78, 201, 176, 0.15);
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border-bottom: 1px solid rgba(78, 201, 176, 0.3);
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color: var(--pass);
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}
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.verify-body {
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padding: 0.6rem 0.8rem;
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background: var(--bg-code);
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font-size: 0.85rem;
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}
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.verify-body p {
|
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margin: 0.3rem 0;
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}
|
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|
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.check-pass {
|
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color: var(--pass);
|
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}
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|
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.check-fail {
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color: var(--fail);
|
||||
}
|
||||
|
||||
.tradition {
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font-style: italic;
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||||
color: var(--fg-dim);
|
||||
margin: 0.3rem 0 0.6rem;
|
||||
font-size: 0.88rem;
|
||||
}
|
||||
|
||||
/* Tables */
|
||||
.table-wrapper {
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||||
overflow-x: auto;
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||||
-webkit-overflow-scrolling: touch;
|
||||
margin: 0.8rem 0;
|
||||
border-radius: 6px;
|
||||
}
|
||||
|
||||
table {
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||||
width: 100%;
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||||
border-collapse: collapse;
|
||||
font-size: 0.88rem;
|
||||
}
|
||||
|
||||
th, td {
|
||||
border: 1px solid var(--border);
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||||
padding: 0.5rem 0.6rem;
|
||||
text-align: left;
|
||||
}
|
||||
|
||||
th {
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||||
background: var(--bg-code);
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||||
font-weight: 600;
|
||||
color: var(--accent2);
|
||||
white-space: nowrap;
|
||||
}
|
||||
|
||||
td {
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||||
white-space: normal;
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||||
}
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||||
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||||
tr:nth-child(even) {
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||||
background: var(--table-stripe);
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||||
}
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||||
|
||||
/* Responsive card tables on mobile */
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||||
@media (max-width: 600px) {
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||||
table.responsive-cards,
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||||
table.responsive-cards thead,
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||||
table.responsive-cards tbody,
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||||
table.responsive-cards tr,
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||||
table.responsive-cards th,
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||||
table.responsive-cards td {
|
||||
display: block;
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||||
}
|
||||
|
||||
table.responsive-cards thead {
|
||||
position: absolute;
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||||
width: 1px;
|
||||
height: 1px;
|
||||
overflow: hidden;
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||||
clip: rect(0, 0, 0, 0);
|
||||
}
|
||||
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||||
table.responsive-cards tr {
|
||||
margin-bottom: 0.8rem;
|
||||
border: 1px solid var(--border);
|
||||
border-radius: 6px;
|
||||
background: var(--bg-code);
|
||||
overflow: hidden;
|
||||
}
|
||||
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||||
table.responsive-cards tr:nth-child(even) {
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||||
background: var(--bg-code);
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||||
}
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||||
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||||
table.responsive-cards td {
|
||||
border: none;
|
||||
border-bottom: 1px solid var(--border);
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||||
padding: 0.5rem 0.7rem;
|
||||
}
|
||||
|
||||
table.responsive-cards td:last-child {
|
||||
border-bottom: none;
|
||||
}
|
||||
|
||||
table.responsive-cards td::before {
|
||||
content: attr(data-label);
|
||||
display: block;
|
||||
font-weight: 600;
|
||||
color: var(--accent2);
|
||||
font-size: 0.75rem;
|
||||
text-transform: uppercase;
|
||||
letter-spacing: 0.03em;
|
||||
margin-bottom: 0.15rem;
|
||||
}
|
||||
}
|
||||
|
||||
/* Simple 2-col tables */
|
||||
table.simple-table th,
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||||
table.simple-table td {
|
||||
white-space: nowrap;
|
||||
}
|
||||
|
||||
/* Lists */
|
||||
ul, ol {
|
||||
margin: 0.5rem 0 0.5rem 1.2rem;
|
||||
}
|
||||
|
||||
li {
|
||||
margin: 0.3rem 0;
|
||||
}
|
||||
|
||||
li > ul, li > ol {
|
||||
margin: 0.2rem 0 0.2rem 1rem;
|
||||
}
|
||||
|
||||
/* Horizontal rules */
|
||||
hr {
|
||||
border: none;
|
||||
border-top: 1px solid var(--border);
|
||||
margin: 2rem 0;
|
||||
}
|
||||
|
||||
/* Blockquotes */
|
||||
blockquote {
|
||||
border-left: 3px solid var(--accent);
|
||||
padding: 0.4rem 0.8rem;
|
||||
margin: 0.8rem 0;
|
||||
color: var(--fg-dim);
|
||||
background: var(--bg-code);
|
||||
border-radius: 0 4px 4px 0;
|
||||
}
|
||||
|
||||
/* Mobile adjustments */
|
||||
@media (max-width: 600px) {
|
||||
body {
|
||||
padding: 0.6rem;
|
||||
}
|
||||
|
||||
pre {
|
||||
padding: 0.6rem;
|
||||
border-radius: 4px;
|
||||
}
|
||||
|
||||
table { font-size: 0.82rem; }
|
||||
th, td { padding: 0.4rem 0.5rem; }
|
||||
}
|
||||
|
||||
/* Scroll hint for wide content on mobile */
|
||||
.scroll-hint {
|
||||
text-align: center;
|
||||
font-size: 0.72rem;
|
||||
color: var(--fg-dim);
|
||||
margin-top: -0.4rem;
|
||||
margin-bottom: 0.6rem;
|
||||
}
|
||||
|
||||
@media (min-width: 768px) {
|
||||
.scroll-hint {
|
||||
display: none;
|
||||
}
|
||||
}
|
||||
|
||||
/* Print-friendly */
|
||||
@media print {
|
||||
body { background: white; color: black; }
|
||||
pre { border-color: #ccc; background: #f8f8f8; }
|
||||
h1 { color: #333; border-color: #333; }
|
||||
h2 { color: #555; }
|
||||
}
|
||||
</style>
|
||||
</head>
|
||||
<body>
|
||||
<article>
|
||||
<h1>Formal Verification Pipeline: Proving L1→L0 Lowering Correctness</h1>
|
||||
|
||||
<p>This document walks through the formal verification pipeline that proves the L1→L0 compilation preserves semantics. Three verification tools — inspired by real-world formal methods — examine the lowering from different angles. Together, they provide strong evidence that the compiler does what it claims.</p>
|
||||
|
||||
<p>The program used is <code>examples/product.l1</code> — a product tracker with multi-field state, compound arithmetic, and observable output. It exercises every DSL feature: actors, windows, message handlers, leaves, pipelines, and bounded execution.</p>
|
||||
|
||||
<p><strong>Reproducibility.</strong> Every output shown here can be regenerated:</p>
|
||||
<pre><code class="language-bash">cargo run -- verify examples/product.l1 # full verification pipeline
|
||||
cargo run -- examples/product.l1 # execution output
|
||||
cargo run -- examples/product.l1 --dump-ir # all IRs + hex dump
|
||||
</code></pre>
|
||||
|
||||
<h2>Pipeline Overview</h2>
|
||||
|
||||
<div class="pipeline">
|
||||
<div class="pipeline-title">Verification Pipeline</div>
|
||||
<div class="pipeline-flow">
|
||||
<div class="pf-node">DSL Source <small>(.l1)</small></div>
|
||||
<div class="pf-edge">Parse</div>
|
||||
<div class="pf-node">L1 IR</div>
|
||||
<div class="pf-edge pf-gate">Verify (L1)</div>
|
||||
<div class="pf-node">L1 IR <small>(verified)</small></div>
|
||||
<div class="pf-edge">Emit</div>
|
||||
<div class="pf-node">L0 IR</div>
|
||||
<div class="pf-edge pf-gate">Verify (L0)</div>
|
||||
<div class="pf-node">L0 IR <small>(verified)</small></div>
|
||||
<div class="pf-edge pf-gate">Translation Validation</div>
|
||||
<div class="pf-node pf-pass">Verification Report</div>
|
||||
</div>
|
||||
</div>
|
||||
|
||||
<p>After the standard L0 verification gate passes, the translation validation phase runs three independent verification tools. All three must pass for the translation to be considered correct.</p>
|
||||
|
||||
<h2>The Example Program</h2>
|
||||
|
||||
<pre><code class="language-clike">actor ledger {
|
||||
state {
|
||||
count: u64 = 0
|
||||
total: u64 = 0
|
||||
}
|
||||
|
||||
window summary : (count, total)
|
||||
readers(report)
|
||||
|
||||
on Purchase(price: u64, qty: u64) {
|
||||
count = count + qty
|
||||
total = total + (price * qty)
|
||||
}
|
||||
}
|
||||
|
||||
leaf buy {
|
||||
process {
|
||||
forward(ledger, Purchase(7, 3))
|
||||
}
|
||||
}
|
||||
|
||||
leaf report {
|
||||
reads ledger.summary
|
||||
process {
|
||||
read(ledger.summary.total)
|
||||
emit(total)
|
||||
}
|
||||
}
|
||||
|
||||
pipeline main {
|
||||
buy -> ledger -> report
|
||||
}
|
||||
|
||||
core main {
|
||||
actors: [ledger]
|
||||
leaves: [buy, report]
|
||||
pipelines: [main]
|
||||
steps: 4
|
||||
}
|
||||
</code></pre>
|
||||
|
||||
<p>After 4 steps: <code>count</code> = 12, <code>total</code> = 84, emitted values = [21, 42, 63, 84].</p>
|
||||
|
||||
<p>This program exercises every verification-relevant feature:</p>
|
||||
<ul>
|
||||
<li><strong>Multi-field state</strong> — two fields at different offsets, both mutated per step</li>
|
||||
<li><strong>Compound arithmetic</strong> — <code>price * qty</code> nested inside an addition</li>
|
||||
<li><strong>Window reads</strong> — a leaf reading actor state through a read-only window</li>
|
||||
<li><strong>Observable output</strong> — emitted values that both L1 and L0 must agree on</li>
|
||||
</ul>
|
||||
|
||||
<hr>
|
||||
|
||||
<h2>Tool 1: L1 Reference Interpreter</h2>
|
||||
|
||||
<p class="tradition">Tradition: CompCert’s translation validation requires a reference semantics — a definition of what the source program means, independent of the compiler.</p>
|
||||
|
||||
<p>The L1 reference interpreter executes L1 IR directly, without lowering to L0. It steps through pipeline stages, dispatches messages to actor handlers, updates state, reads windows, and collects emitted outputs. The interpreter <em>is</em> the specification: if L0 execution produces the same observable trace, the lowering preserved semantics.</p>
|
||||
|
||||
<h3>Execution trace for product.l1</h3>
|
||||
|
||||
<pre><code>--- Step 0 ---
|
||||
send Purchase([7, 3]) -> ledger
|
||||
read ledger.summary.total = 21
|
||||
emit 21
|
||||
ledger { count=3, total=21 }
|
||||
--- Step 1 ---
|
||||
send Purchase([7, 3]) -> ledger
|
||||
read ledger.summary.total = 42
|
||||
emit 42
|
||||
ledger { count=6, total=42 }
|
||||
--- Step 2 ---
|
||||
send Purchase([7, 3]) -> ledger
|
||||
read ledger.summary.total = 63
|
||||
emit 63
|
||||
ledger { count=9, total=63 }
|
||||
--- Step 3 ---
|
||||
send Purchase([7, 3]) -> ledger
|
||||
read ledger.summary.total = 84
|
||||
emit 84
|
||||
ledger { count=12, total=84 }
|
||||
--- Final ---
|
||||
ledger { count=12, total=84 }
|
||||
outputs: [21, 42, 63, 84]
|
||||
</code></pre>
|
||||
|
||||
<p>Each step follows pipeline order: <code>buy</code> forwards <code>Purchase(7, 3)</code> to <code>ledger</code>, the actor processes it (multiplying price × qty and accumulating), then <code>report</code> reads the updated total through the window and emits it. State evolves deterministically: count increments by 3 each step, total by 21.</p>
|
||||
|
||||
<h3>Operational semantics</h3>
|
||||
|
||||
<p>The interpreter’s step function:</p>
|
||||
<ol>
|
||||
<li>For each pipeline in the core’s pipeline list:</li>
|
||||
<li>Walk stages left to right.</li>
|
||||
<li>If the stage is a <strong>leaf</strong>: execute its actions (forward messages, read windows, emit outputs).</li>
|
||||
<li>If the stage is an <strong>actor</strong>: pop messages from its queue and execute matching handlers.</li>
|
||||
<li>After all pipelines complete: record the trace step (state snapshot, messages, reads, outputs).</li>
|
||||
</ol>
|
||||
|
||||
<p>This is the <em>reference semantics</em>. Any correct lowering must produce the same final state and the same output sequence.</p>
|
||||
|
||||
<hr>
|
||||
|
||||
<h2>Tool 2: Trace Equivalence Checker</h2>
|
||||
|
||||
<p class="tradition">Tradition: CompCert’s verified C compiler uses translation validation — running both the source semantics and the compiled output on the same input, then comparing observable behavior.</p>
|
||||
|
||||
<p>The trace equivalence checker runs the L1 reference interpreter and the L0 codegen+execution on the same program, then compares final actor states field by field and emitted output sequences element by element.</p>
|
||||
|
||||
<h3>Side-by-side comparison for product.l1</h3>
|
||||
|
||||
<div class="table-wrapper">
|
||||
<table class="responsive-cards">
|
||||
<thead>
|
||||
<tr>
|
||||
<th>Observable</th>
|
||||
<th>L1 Interpreter</th>
|
||||
<th>L0 Execution</th>
|
||||
<th>Match</th>
|
||||
</tr>
|
||||
</thead>
|
||||
<tbody>
|
||||
<tr>
|
||||
<td data-label="Observable"><code>ledger.count</code> (final)</td>
|
||||
<td data-label="L1 Interpreter">12</td>
|
||||
<td data-label="L0 Execution"><code>ledger_state[0]</code> = 12</td>
|
||||
<td data-label="Match"><span class="check-pass">✓</span></td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Observable"><code>ledger.total</code> (final)</td>
|
||||
<td data-label="L1 Interpreter">84</td>
|
||||
<td data-label="L0 Execution"><code>ledger_state[8]</code> = 84</td>
|
||||
<td data-label="Match"><span class="check-pass">✓</span></td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Observable">Output[0]</td>
|
||||
<td data-label="L1 Interpreter">21</td>
|
||||
<td data-label="L0 Execution">21</td>
|
||||
<td data-label="Match"><span class="check-pass">✓</span></td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Observable">Output[1]</td>
|
||||
<td data-label="L1 Interpreter">42</td>
|
||||
<td data-label="L0 Execution">42</td>
|
||||
<td data-label="Match"><span class="check-pass">✓</span></td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Observable">Output[2]</td>
|
||||
<td data-label="L1 Interpreter">63</td>
|
||||
<td data-label="L0 Execution">63</td>
|
||||
<td data-label="Match"><span class="check-pass">✓</span></td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Observable">Output[3]</td>
|
||||
<td data-label="L1 Interpreter">84</td>
|
||||
<td data-label="L0 Execution">84</td>
|
||||
<td data-label="Match"><span class="check-pass">✓</span></td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
|
||||
<div class="verify-box">
|
||||
<div class="verify-header pass"><span>Trace Equivalence</span> <span>PASS</span></div>
|
||||
<div class="verify-body">
|
||||
<p>Outputs match: 4 values. Final states agree across 1 actor.</p>
|
||||
</div>
|
||||
</div>
|
||||
|
||||
<h3>What it catches</h3>
|
||||
|
||||
<p>If the emitter generated <code>Sub</code> instead of <code>Add</code> for the handler’s <code>count = count + qty</code>:</p>
|
||||
<ul>
|
||||
<li>L1 interpreter would compute <code>count = 0 + 3 = 3</code> at step 0</li>
|
||||
<li>L0 execution would compute <code>count = 0 - 3 = 18446744073709551613</code> (wrapping subtraction)</li>
|
||||
<li>Diagnostic: <code>"final state mismatch: ledger.count = 3 (L1) vs 18446744073709551613 (L0)"</code></li>
|
||||
</ul>
|
||||
|
||||
<p>This is not hypothetical — the test suite includes a deliberate corruption test that verifies this exact scenario.</p>
|
||||
|
||||
<h3>How it differs from CompCert</h3>
|
||||
|
||||
<p>CompCert’s translation validation runs on each compilation pass independently, with pass-specific simulation relations. Our version is end-to-end: L1 interpreter vs. final x86-64 execution. This is coarser (it can’t pinpoint <em>which</em> pass introduced a bug) but simpler and catches any bug that affects observable behavior, regardless of which compilation stage introduced it.</p>
|
||||
|
||||
<hr>
|
||||
|
||||
<h2>Tool 3: Structural Correspondence Checker</h2>
|
||||
|
||||
<p class="tradition">Tradition: Refinement type systems (Liquid Haskell, F*) prove that a concrete implementation refines an abstract specification by establishing a correspondence between abstract and concrete types.</p>
|
||||
|
||||
<p>The structural checker walks L1 IR and L0 IR in parallel, verifying structural invariants. Unlike the trace checker (which tests specific inputs), the structural checker verifies properties that hold for <em>all</em> inputs to the program.</p>
|
||||
|
||||
<h3>Check 1: Actor state → L0 region mapping</h3>
|
||||
|
||||
<div class="table-wrapper">
|
||||
<table class="responsive-cards">
|
||||
<thead>
|
||||
<tr>
|
||||
<th>L1 Field</th>
|
||||
<th>L0 Region</th>
|
||||
<th>Offset</th>
|
||||
<th>Init Store</th>
|
||||
<th>Status</th>
|
||||
</tr>
|
||||
</thead>
|
||||
<tbody>
|
||||
<tr>
|
||||
<td data-label="L1 Field"><code>ledger.count</code> : u64</td>
|
||||
<td data-label="L0 Region"><code>ledger_state</code> (State, 16 bytes)</td>
|
||||
<td data-label="Offset">0</td>
|
||||
<td data-label="Init Store"><code>store.64 ledger_state[0], r0</code></td>
|
||||
<td data-label="Status"><span class="check-pass">✓</span></td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="L1 Field"><code>ledger.total</code> : u64</td>
|
||||
<td data-label="L0 Region"><code>ledger_state</code> (State, 16 bytes)</td>
|
||||
<td data-label="Offset">8</td>
|
||||
<td data-label="Init Store"><code>store.64 ledger_state[8], r0</code></td>
|
||||
<td data-label="Status"><span class="check-pass">✓</span></td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
|
||||
<h3>Check 2: Handler → queue_pop + arithmetic</h3>
|
||||
|
||||
<div class="table-wrapper">
|
||||
<table class="responsive-cards">
|
||||
<thead>
|
||||
<tr>
|
||||
<th>L1 Handler</th>
|
||||
<th>L0 Queue Region</th>
|
||||
<th>Args</th>
|
||||
<th>Pops</th>
|
||||
<th>Arith (L1)</th>
|
||||
<th>Arith (L0)</th>
|
||||
</tr>
|
||||
</thead>
|
||||
<tbody>
|
||||
<tr>
|
||||
<td data-label="L1 Handler"><code>ledger.on Purchase</code></td>
|
||||
<td data-label="L0 Queue Region"><code>ledger_purchase_queue</code> (Queue)</td>
|
||||
<td data-label="Args">2</td>
|
||||
<td data-label="Pops">2 <span class="check-pass">✓</span></td>
|
||||
<td data-label="Arith (L1)">3</td>
|
||||
<td data-label="Arith (L0)">≥3 <span class="check-pass">✓</span></td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
|
||||
<h3>Check 3: Leaf forward → queue_push</h3>
|
||||
|
||||
<div class="table-wrapper">
|
||||
<table class="simple-table">
|
||||
<thead>
|
||||
<tr><th>L1 Leaf</th><th>Forward Target</th><th>L0 Queue Push</th><th>Status</th></tr>
|
||||
</thead>
|
||||
<tbody>
|
||||
<tr><td><code>buy</code></td><td><code>ledger</code></td><td><code>queue_push ledger_purchase_queue</code></td><td><span class="check-pass">✓</span></td></tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
|
||||
<h3>Check 4: Window read → state region load</h3>
|
||||
|
||||
<div class="table-wrapper">
|
||||
<table class="simple-table">
|
||||
<thead>
|
||||
<tr><th>L1 Leaf</th><th>Window Read</th><th>L0 Load</th><th>Status</th></tr>
|
||||
</thead>
|
||||
<tbody>
|
||||
<tr><td><code>report</code></td><td><code>ledger.summary.total</code></td><td><code>load.64 ledger_state[8]</code></td><td><span class="check-pass">✓</span></td></tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
|
||||
<h3>Checks 5–7: Emit, control structure, step counter</h3>
|
||||
|
||||
<div class="table-wrapper">
|
||||
<table class="simple-table">
|
||||
<thead>
|
||||
<tr><th>Check</th><th>Expected</th><th>Found</th><th>Status</th></tr>
|
||||
</thead>
|
||||
<tbody>
|
||||
<tr><td>Emit → Output region</td><td><code>region output</code> of kind Output</td><td>Present</td><td><span class="check-pass">✓</span></td></tr>
|
||||
<tr><td>Control blocks</td><td>entry, loop_check, step, exit</td><td>All present</td><td><span class="check-pass">✓</span></td></tr>
|
||||
<tr><td>Step counter</td><td><code>step_counter</code> region (Control)</td><td>Present</td><td><span class="check-pass">✓</span></td></tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
|
||||
<div class="verify-box">
|
||||
<div class="verify-header pass"><span>Structural Correspondence</span> <span>PASS</span></div>
|
||||
<div class="verify-body">
|
||||
<p>All structural invariants verified. Every L1 construct maps to the expected L0 structure.</p>
|
||||
</div>
|
||||
</div>
|
||||
|
||||
<h3>What it catches vs. trace equivalence</h3>
|
||||
|
||||
<p>The trace checker catches bugs that manifest on a specific input. The structural checker catches <em>classes</em> of bugs:</p>
|
||||
<ul>
|
||||
<li>A missing state field initialization (no <code>store</code> in <code>entry</code> for a field)</li>
|
||||
<li>A wrong queue region kind (using <code>State</code> instead of <code>Queue</code>)</li>
|
||||
<li>A mismatched argument count (handler expects 2 args but only 1 <code>queue_pop</code>)</li>
|
||||
<li>A missing control block (no <code>loop_check</code> means no bounded execution)</li>
|
||||
</ul>
|
||||
|
||||
<hr>
|
||||
|
||||
<h2>Tool 4: Bounded State Space Explorer</h2>
|
||||
|
||||
<p class="tradition">Tradition: CBMC (bounded model checking for C) exhaustively explores all reachable states within a finite bound. Our bounded explorer exploits the fact that L1 programs have inherently finite state spaces.</p>
|
||||
|
||||
<p>The bounded explorer runs the L1 interpreter through all steps, collecting every unique actor state. It then verifies that all L0 blocks are reachable, all L0 regions are accessed, the loop limit matches, and control flow is well-formed.</p>
|
||||
|
||||
<h3>State space enumeration for product.l1</h3>
|
||||
|
||||
<div class="table-wrapper">
|
||||
<table class="responsive-cards">
|
||||
<thead>
|
||||
<tr>
|
||||
<th>Step</th>
|
||||
<th>ledger.count</th>
|
||||
<th>ledger.total</th>
|
||||
<th>State ID</th>
|
||||
</tr>
|
||||
</thead>
|
||||
<tbody>
|
||||
<tr>
|
||||
<td data-label="Step">(init)</td>
|
||||
<td data-label="ledger.count">0</td>
|
||||
<td data-label="ledger.total">0</td>
|
||||
<td data-label="State ID">S0</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Step">0</td>
|
||||
<td data-label="ledger.count">3</td>
|
||||
<td data-label="ledger.total">21</td>
|
||||
<td data-label="State ID">S1</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Step">1</td>
|
||||
<td data-label="ledger.count">6</td>
|
||||
<td data-label="ledger.total">42</td>
|
||||
<td data-label="State ID">S2</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Step">2</td>
|
||||
<td data-label="ledger.count">9</td>
|
||||
<td data-label="ledger.total">63</td>
|
||||
<td data-label="State ID">S3</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Step">3</td>
|
||||
<td data-label="ledger.count">12</td>
|
||||
<td data-label="ledger.total">84</td>
|
||||
<td data-label="State ID">S4</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
|
||||
<h3>Exploration statistics</h3>
|
||||
|
||||
<div class="table-wrapper">
|
||||
<table class="simple-table">
|
||||
<thead>
|
||||
<tr><th>Metric</th><th>Value</th></tr>
|
||||
</thead>
|
||||
<tbody>
|
||||
<tr><td>States explored</td><td>5</td></tr>
|
||||
<tr><td>L0 blocks reached</td><td>4/4 (100%)</td></tr>
|
||||
<tr><td>L0 regions used</td><td>4/4 (100%)</td></tr>
|
||||
<tr><td>L0 loop limit</td><td>4 (matches L1 core steps <span class="check-pass">✓</span>)</td></tr>
|
||||
<tr><td>Exit block has <code>Terminate</code></td><td><span class="check-pass">✓</span></td></tr>
|
||||
<tr><td>Control flow well-formed</td><td><span class="check-pass">✓</span></td></tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
|
||||
<div class="verify-box">
|
||||
<div class="verify-header pass"><span>Bounded Model Check</span> <span>PASS</span></div>
|
||||
<div class="verify-body">
|
||||
<p>5 unique states explored across 4 steps. All 4 L0 blocks reachable, all 4 regions accessed. Bounded execution verified.</p>
|
||||
</div>
|
||||
</div>
|
||||
|
||||
<h3>Why bounded model checking works here</h3>
|
||||
|
||||
<p>Traditional bounded model checkers like CBMC handle arbitrary C programs with unbounded loops, dynamic memory, and pointer arithmetic — requiring SAT/SMT solvers. Our DSL is fundamentally different:</p>
|
||||
<ul>
|
||||
<li><strong>Execution is bounded by construction.</strong> The <code>steps: N</code> declaration means the program always terminates in exactly N iterations. No SAT solver needed.</li>
|
||||
<li><strong>State is finite and small.</strong> Actor fields are typed (<code>u64</code>) and initialized with known values. With known constant inputs each step, the state at step N is fully determined.</li>
|
||||
<li><strong>The state space is tractable.</strong> For product.l1: 5 states (init + 4 steps). The “bounded” model check is actually a <em>complete</em> check — there are no states outside the bound.</li>
|
||||
</ul>
|
||||
|
||||
<hr>
|
||||
|
||||
<h2>Verification Report</h2>
|
||||
|
||||
<p>Running <code>cargo run -- verify examples/product.l1</code> produces:</p>
|
||||
|
||||
<pre><code>=== Translation Validation Report ===
|
||||
[PASS] Trace Equivalence
|
||||
[Trace Equivalence] INFO: outputs match: 4 values, final states agree across 1 actors
|
||||
[PASS] Structural Correspondence
|
||||
[Structural Correspondence] INFO: all structural invariants verified
|
||||
[PASS] Bounded Model Check
|
||||
[Bounded Model Check] INFO: explored 5 unique states across 4 steps
|
||||
[Bounded Model Check] INFO: L0 loop limit (4) matches L1 core steps
|
||||
[Bounded Model Check] INFO: all 4 L0 blocks reachable, all 4 regions accessed, bounded execution verified
|
||||
--- Field Mappings ---
|
||||
ledger.count -> ledger_state[0]
|
||||
ledger.total -> ledger_state[8]
|
||||
--- Exploration Stats ---
|
||||
states explored: 5
|
||||
L0 blocks reached: 4/4
|
||||
L0 regions used: 4/4
|
||||
Overall: PASS
|
||||
</code></pre>
|
||||
|
||||
<h3>Field mappings</h3>
|
||||
|
||||
<p>The structural correspondence checker produces a mapping between L1 actor fields and their L0 region locations:</p>
|
||||
|
||||
<div class="table-wrapper">
|
||||
<table class="simple-table">
|
||||
<thead>
|
||||
<tr><th>L1 Field</th><th>L0 Location</th></tr>
|
||||
</thead>
|
||||
<tbody>
|
||||
<tr><td><code>ledger.count</code></td><td><code>ledger_state[0]</code></td></tr>
|
||||
<tr><td><code>ledger.total</code></td><td><code>ledger_state[8]</code></td></tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
|
||||
<p>This mapping is the <em>refinement relation</em> — the bridge between L1’s abstract named fields and L0’s concrete byte offsets. Every field is accounted for, every offset is correct, every access in L0 can be traced back to a field in L1.</p>
|
||||
|
||||
<hr>
|
||||
|
||||
<h2>What Else Could Be Built</h2>
|
||||
|
||||
<p>The three tools verify the lowering through concrete execution, structural analysis, and bounded enumeration. More sophisticated techniques from the formal verification literature could extend the pipeline further. These are not built — the DSL’s finite, bounded nature makes them unnecessary — but they represent natural next steps for a larger system.</p>
|
||||
|
||||
<h3>Symbolic Execution Engine (KLEE-inspired)</h3>
|
||||
|
||||
<p><strong>What it is:</strong> Instead of running the program with concrete values (price=7, qty=3), symbolic execution treats inputs as symbolic variables and tracks constraints along execution paths. Each branch creates a fork with the branch condition added as a constraint.</p>
|
||||
|
||||
<p><strong>What it would add:</strong> The current verification proves correctness for the program’s specific constants. Symbolic execution would prove correctness for <em>parameterized</em> inputs — that for <em>any</em> price P and quantity Q, the lowering preserves <code>total = total + P * Q</code>.</p>
|
||||
|
||||
<p><strong>Why it’s not needed yet:</strong> L1 programs have fixed inputs (leaf actions use constant expressions). There are no symbolic parameters — every execution is fully determined by the source text.</p>
|
||||
|
||||
<h3>Inductive Invariant Synthesis (IC3/PDR-inspired)</h3>
|
||||
|
||||
<p><strong>What it is:</strong> IC3/PDR synthesizes inductive invariants — properties that hold at every reachable state and are preserved by every transition. It works backward from a safety property, finding increasingly strong invariants until it proves the property or finds a counterexample.</p>
|
||||
|
||||
<p><strong>What it would add:</strong> Proofs that hold across <em>arbitrary</em> step counts. Our bounded explorer verifies <code>steps: 4</code>. IC3 could prove that for <code>steps: N</code> (any N), the lowering is correct — that the correspondence between L1 and L0 is an inductive invariant of the step function.</p>
|
||||
|
||||
<p><strong>Why it’s not needed yet:</strong> L1 cores declare a fixed step count. We enumerate all states. If the step count were parameterized, inductive invariant synthesis would be essential.</p>
|
||||
|
||||
<h3>Proof Certificate Generation (CompCert-inspired)</h3>
|
||||
|
||||
<p><strong>What it is:</strong> CompCert generates machine-checkable proof certificates verified by an independent proof checker (Coq). The certificate proves the compiled code refines the source semantics, and the proof checker confirms validity without trusting the compiler.</p>
|
||||
|
||||
<p><strong>What it would add:</strong> Independent verifiability. Our verification tools are part of the same codebase as the compiler — a bug in the verifier could mask a bug in the compiler. Proof certificates allow an external tool to independently confirm correctness.</p>
|
||||
|
||||
<p><strong>Why it’s not needed yet:</strong> The system is small enough for direct auditing. The three tools are independent of compilation logic. Proof certificates become valuable when the compiler is too complex for direct review.</p>
|
||||
|
||||
<hr>
|
||||
|
||||
<h2>Pipeline Summary</h2>
|
||||
|
||||
<div class="pipeline">
|
||||
<div class="pipeline-title">Full Verification Pipeline — product.l1</div>
|
||||
<div class="pipeline-flow">
|
||||
<div class="pf-node">Parse <small>DSL → L1 IR</small></div>
|
||||
<div class="pf-edge pf-gate">Verify L1 (6 checks)</div>
|
||||
<div class="pf-node">Emit <small>L1 IR → L0 IR</small></div>
|
||||
<div class="pf-edge pf-gate">Verify L0 (7 checks)</div>
|
||||
<div class="pf-node">Translation Validation</div>
|
||||
<div class="pf-edge">Tool 1: Trace Equivalence</div>
|
||||
<div class="pf-node pf-pass">PASS <small>4 outputs, 1 actor</small></div>
|
||||
<div class="pf-edge">Tool 2: Structural Correspondence</div>
|
||||
<div class="pf-node pf-pass">PASS <small>7 invariants verified</small></div>
|
||||
<div class="pf-edge">Tool 3: Bounded Model Check</div>
|
||||
<div class="pf-node pf-pass">PASS <small>5 states, 4/4 blocks, 4/4 regions</small></div>
|
||||
<div class="pf-edge"></div>
|
||||
<div class="pf-node pf-final">Overall: PASS</div>
|
||||
</div>
|
||||
</div>
|
||||
|
||||
<h3>Commands to reproduce</h3>
|
||||
|
||||
<pre><code class="language-bash"># Full verification pipeline
|
||||
cargo run -- verify examples/product.l1
|
||||
|
||||
# Run the program (standard execution)
|
||||
cargo run -- examples/product.l1
|
||||
|
||||
# Dump all intermediate representations
|
||||
cargo run -- examples/product.l1 --dump-ir
|
||||
|
||||
# Run the REPL and verify interactively
|
||||
cargo run -- repl
|
||||
# then: :load examples/product.l1
|
||||
# then: :verify
|
||||
|
||||
# Run all tests (includes verification tool tests)
|
||||
cargo test
|
||||
</code></pre>
|
||||
|
||||
</article>
|
||||
<script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/prism.min.js"></script>
|
||||
<script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/components/prism-bash.min.js"></script>
|
||||
<script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/components/prism-clike.min.js"></script>
|
||||
</body>
|
||||
</html>
|
||||
437
formal_verification_demo.md
Normal file
437
formal_verification_demo.md
Normal file
|
|
@ -0,0 +1,437 @@
|
|||
# Formal Verification Pipeline: Proving L1→L0 Lowering Correctness
|
||||
|
||||
This document walks through the formal verification pipeline that proves the L1→L0 compilation preserves semantics. Three verification tools — inspired by real-world formal methods — examine the lowering from different angles. Together, they provide strong evidence that the compiler does what it claims.
|
||||
|
||||
The program used is `examples/product.l1` — a product tracker with multi-field state, compound arithmetic, and observable output. It exercises every DSL feature: actors, windows, message handlers, leaves, pipelines, and bounded execution.
|
||||
|
||||
**Reproducibility.** Every output shown here can be regenerated:
|
||||
|
||||
```bash
|
||||
cargo run -- verify examples/product.l1 # full verification pipeline
|
||||
cargo run -- examples/product.l1 # execution output
|
||||
cargo run -- examples/product.l1 --dump-ir # all IRs + hex dump
|
||||
```
|
||||
|
||||
## Pipeline Overview
|
||||
|
||||
The verification pipeline extends the standard compilation pipeline with a translation validation phase:
|
||||
|
||||
```
|
||||
┌──────────┐ ┌───────┐ ┌───────────┐ ┌───────┐ ┌───────────┐
|
||||
│ DSL │ │ L1 │ │ L1 IR │ │ L0 │ │ L0 IR │
|
||||
│ Source │─────▶│ IR │─────▶│ (verified) │─────▶│ IR │─────▶│ (verified) │
|
||||
│ (.l1) │ │ │ │ │ │ │ │ │
|
||||
└──────────┘ └───────┘ └───────────┘ └───────┘ └───────────┘
|
||||
Parse Verify(L1) Emit Verify(L0)
|
||||
│
|
||||
▼
|
||||
┌─────────────────────────┐
|
||||
│ Translation Validation │
|
||||
│ ┌───────────────────┐ │
|
||||
│ │ Trace Equivalence │ │
|
||||
│ │ (CompCert-style) │ │
|
||||
│ └───────────────────┘ │
|
||||
│ ┌───────────────────┐ │
|
||||
│ │ Structural │ │
|
||||
│ │ Correspondence │ │
|
||||
│ │ (Refinement-type) │ │
|
||||
│ └───────────────────┘ │
|
||||
│ ┌───────────────────┐ │
|
||||
│ │ Bounded Model │ │
|
||||
│ │ Checking (CBMC) │ │
|
||||
│ └───────────────────┘ │
|
||||
└─────────────────────────┘
|
||||
│
|
||||
▼
|
||||
┌─────────────────┐
|
||||
│ Verification │
|
||||
│ Report │
|
||||
│ (PASS / FAIL) │
|
||||
└─────────────────┘
|
||||
```
|
||||
|
||||
After the standard L0 verification gate passes, the translation validation phase runs three independent verification tools. All three must pass for the translation to be considered correct.
|
||||
|
||||
## The Example Program
|
||||
|
||||
```l1
|
||||
actor ledger {
|
||||
state {
|
||||
count: u64 = 0
|
||||
total: u64 = 0
|
||||
}
|
||||
|
||||
window summary : (count, total)
|
||||
readers(report)
|
||||
|
||||
on Purchase(price: u64, qty: u64) {
|
||||
count = count + qty
|
||||
total = total + (price * qty)
|
||||
}
|
||||
}
|
||||
|
||||
leaf buy {
|
||||
process {
|
||||
forward(ledger, Purchase(7, 3))
|
||||
}
|
||||
}
|
||||
|
||||
leaf report {
|
||||
reads ledger.summary
|
||||
process {
|
||||
read(ledger.summary.total)
|
||||
emit(total)
|
||||
}
|
||||
}
|
||||
|
||||
pipeline main {
|
||||
buy -> ledger -> report
|
||||
}
|
||||
|
||||
core main {
|
||||
actors: [ledger]
|
||||
leaves: [buy, report]
|
||||
pipelines: [main]
|
||||
steps: 4
|
||||
}
|
||||
```
|
||||
|
||||
After 4 steps: `count` = 12, `total` = 84, emitted values = [21, 42, 63, 84].
|
||||
|
||||
This program is ideal for verification because it exercises:
|
||||
- **Multi-field state** — two fields at different offsets, both mutated per step
|
||||
- **Compound arithmetic** — `price * qty` nested inside an addition
|
||||
- **Window reads** — a leaf reading actor state through a read-only window
|
||||
- **Observable output** — emitted values that both L1 and L0 must agree on
|
||||
|
||||
---
|
||||
|
||||
## Tool 1: L1 Reference Interpreter
|
||||
|
||||
**Tradition:** CompCert's translation validation approach requires a *reference semantics* — a definition of what the source program means, independent of the compiler.
|
||||
|
||||
**What it is:** An abstract interpreter that executes L1 IR directly, without lowering to L0. It steps through the program's pipeline stages, dispatches messages to actor handlers, updates state, reads windows, and collects emitted outputs.
|
||||
|
||||
**Why it exists:** To prove the L0 lowering is correct, we need something to compare against. The L1 interpreter *is* the specification. If the L0 execution produces the same observable trace, the lowering preserved semantics.
|
||||
|
||||
### Execution trace for product.l1
|
||||
|
||||
```
|
||||
--- Step 0 ---
|
||||
send Purchase([7, 3]) -> ledger
|
||||
read ledger.summary.total = 21
|
||||
emit 21
|
||||
ledger { count=3, total=21 }
|
||||
--- Step 1 ---
|
||||
send Purchase([7, 3]) -> ledger
|
||||
read ledger.summary.total = 42
|
||||
emit 42
|
||||
ledger { count=6, total=42 }
|
||||
--- Step 2 ---
|
||||
send Purchase([7, 3]) -> ledger
|
||||
read ledger.summary.total = 63
|
||||
emit 63
|
||||
ledger { count=9, total=63 }
|
||||
--- Step 3 ---
|
||||
send Purchase([7, 3]) -> ledger
|
||||
read ledger.summary.total = 84
|
||||
emit 84
|
||||
ledger { count=12, total=84 }
|
||||
--- Final ---
|
||||
ledger { count=12, total=84 }
|
||||
outputs: [21, 42, 63, 84]
|
||||
```
|
||||
|
||||
**What the trace shows:** Each step follows the pipeline order: `buy` forwards a `Purchase(7, 3)` message to `ledger`, the actor processes it (multiplying price × qty and accumulating), then `report` reads the updated total through the window and emits it. The state evolves deterministically: count increments by 3 each step, total by 21.
|
||||
|
||||
### Operational semantics
|
||||
|
||||
The interpreter's step function:
|
||||
|
||||
1. For each pipeline in the core's pipeline list:
|
||||
2. Walk stages left to right.
|
||||
3. If the stage is a **leaf**: execute its actions (forward messages, read windows, emit outputs).
|
||||
4. If the stage is an **actor**: pop messages from its queue and execute matching handlers.
|
||||
5. After all pipelines complete: record the trace step (state snapshot, messages, reads, outputs).
|
||||
|
||||
This is the *reference semantics*. Any correct lowering must produce the same final state and the same output sequence.
|
||||
|
||||
---
|
||||
|
||||
## Tool 2: Trace Equivalence Checker
|
||||
|
||||
**Tradition:** CompCert's verified C compiler uses translation validation — running both the source semantics and the compiled output on the same input, then comparing observable behavior. Our trace equivalence checker follows this pattern exactly.
|
||||
|
||||
**What it does:**
|
||||
1. Runs the L1 reference interpreter (Tool 1) on the program.
|
||||
2. Runs the L0 codegen + x86-64 execution on the same program.
|
||||
3. Compares final actor states field by field: L1 interpreter values vs. L0 region memory.
|
||||
4. Compares emitted output sequences element by element.
|
||||
|
||||
### Side-by-side comparison for product.l1
|
||||
|
||||
| Observable | L1 Interpreter | L0 Execution | Match |
|
||||
|---|---|---|---|
|
||||
| `ledger.count` (final) | 12 | `ledger_state[0]` = 12 | ✓ |
|
||||
| `ledger.total` (final) | 84 | `ledger_state[8]` = 84 | ✓ |
|
||||
| Output[0] | 21 | 21 | ✓ |
|
||||
| Output[1] | 42 | 42 | ✓ |
|
||||
| Output[2] | 63 | 63 | ✓ |
|
||||
| Output[3] | 84 | 84 | ✓ |
|
||||
|
||||
**Result: PASS** — outputs match (4 values), final states agree across 1 actor.
|
||||
|
||||
### What it catches
|
||||
|
||||
If the emitter generated `Sub` instead of `Add` for the handler's `count = count + qty`:
|
||||
- L1 interpreter would compute `count = 0 + 3 = 3` at step 0
|
||||
- L0 execution would compute `count = 0 - 3 = 18446744073709551613` (wrapping subtraction)
|
||||
- Diagnostic: `"final state mismatch: ledger.count = 3 (L1) vs 18446744073709551613 (L0)"`
|
||||
|
||||
This is not a hypothetical — the test suite includes a deliberate corruption test that verifies this exact scenario.
|
||||
|
||||
### How it differs from CompCert
|
||||
|
||||
CompCert's translation validation runs on each compilation pass independently, with pass-specific simulation relations. Our version is end-to-end: L1 interpreter vs. final x86-64 execution. This is coarser (it can't pinpoint *which* pass introduced a bug) but simpler and catches any bug that affects observable behavior, regardless of which compilation stage introduced it.
|
||||
|
||||
---
|
||||
|
||||
## Tool 3: Structural Correspondence Checker
|
||||
|
||||
**Tradition:** Refinement type systems (Liquid Haskell, F*) prove that a concrete implementation refines an abstract specification by establishing a correspondence between abstract and concrete types. Our structural checker does the same at the IR level: it verifies that L1 IR structures map to the expected L0 IR structures.
|
||||
|
||||
**What it does:** Walk the L1 IR and L0 IR in parallel, verifying structural invariants. Unlike the trace checker (which tests specific inputs), the structural checker verifies properties that hold for *all* inputs to the program.
|
||||
|
||||
### Structural checks for product.l1
|
||||
|
||||
**Check 1: Actor state → L0 region mapping**
|
||||
|
||||
| L1 Field | L0 Region | Offset | Size | Init Store in `entry` |
|
||||
|---|---|---|---|---|
|
||||
| `ledger.count` : u64 | `ledger_state` (State, 16 bytes) | 0 | 8 | `store.64 ledger_state[0], r0` ✓ |
|
||||
| `ledger.total` : u64 | `ledger_state` (State, 16 bytes) | 8 | 8 | `store.64 ledger_state[8], r0` ✓ |
|
||||
|
||||
Every L1 actor state field maps to a correctly typed, correctly sized L0 region slot at the right offset.
|
||||
|
||||
**Check 2: Handler → queue_pop + arithmetic**
|
||||
|
||||
| L1 Handler | L0 Queue Region | Args | Pops | Arithmetic Ops (L1) | Arithmetic Ops (L0) |
|
||||
|---|---|---|---|---|---|
|
||||
| `ledger.on Purchase(price, qty)` | `ledger_purchase_queue` (Queue) | 2 | 2 ✓ | 3 (add, mul, add) | ≥3 ✓ |
|
||||
|
||||
The handler has 2 arguments, so L0 must have 2 `queue_pop` operations from the purchase queue. The handler body has 3 arithmetic operations (`count + qty`, `price * qty`, `total + ...`), and L0's step block has at least 3 `Arith` operations.
|
||||
|
||||
**Check 3: Leaf forward → queue_push**
|
||||
|
||||
| L1 Leaf | Forward Target | L0 Queue Push |
|
||||
|---|---|---|
|
||||
| `buy` | `ledger` | `queue_push ledger_purchase_queue` ✓ |
|
||||
|
||||
**Check 4: Window read → state region load**
|
||||
|
||||
| L1 Leaf | Window Read | L0 Load |
|
||||
|---|---|---|
|
||||
| `report` | `ledger.summary.total` | `load.64 ledger_state[8]` ✓ |
|
||||
|
||||
The window field `total` is at offset 8 in the actor's state. The L0 step block contains a load from `ledger_state[8]`.
|
||||
|
||||
**Check 5: Emit → output region**
|
||||
|
||||
L1 has `emit(total)` in leaf `report` → L0 has `region output` of kind `Output` ✓
|
||||
|
||||
**Check 6: Control structure**
|
||||
|
||||
Required L0 blocks present: `entry` ✓, `loop_check` ✓, `step` ✓, `exit` ✓
|
||||
|
||||
**Check 7: Step counter**
|
||||
|
||||
`step_counter` region of kind `Control` exists ✓
|
||||
|
||||
**Result: PASS** — all structural invariants verified.
|
||||
|
||||
### What it catches vs. trace equivalence
|
||||
|
||||
The trace checker catches bugs that manifest on a specific input (the program's constants). The structural checker catches *classes* of bugs:
|
||||
|
||||
- A missing state field initialization (no `store` in `entry` for a field)
|
||||
- A wrong queue region kind (using `State` instead of `Queue`)
|
||||
- A mismatched argument count (handler expects 2 args but only 1 `queue_pop`)
|
||||
- A missing control block (no `loop_check` means no bounded execution)
|
||||
|
||||
These are structural properties of the lowering that hold regardless of what values flow through the program.
|
||||
|
||||
---
|
||||
|
||||
## Tool 4: Bounded State Space Explorer
|
||||
|
||||
**Tradition:** CBMC (bounded model checking for C) and similar tools exhaustively explore all reachable states within a finite bound. Our bounded explorer exploits the fact that L1 programs have inherently finite state spaces: the core's step count bounds execution, and all state fields are initialized with known values with known arithmetic applied each step.
|
||||
|
||||
**What it does:**
|
||||
1. Run the L1 interpreter through all steps, collecting every unique actor state observed.
|
||||
2. Verify all L0 blocks are reachable (no dead blocks).
|
||||
3. Verify all L0 regions are accessed (no dead regions).
|
||||
4. Verify the L0 loop limit matches the L1 core step count.
|
||||
5. Verify the exit block contains `Terminate`.
|
||||
6. Verify control flow: entry → loop_check, loop_check → step/exit, step → loop_check.
|
||||
|
||||
### State space enumeration for product.l1
|
||||
|
||||
| Step | ledger.count | ledger.total | State ID |
|
||||
|---|---|---|---|
|
||||
| (init) | 0 | 0 | S0 |
|
||||
| 0 | 3 | 21 | S1 |
|
||||
| 1 | 6 | 42 | S2 |
|
||||
| 2 | 9 | 63 | S3 |
|
||||
| 3 | 12 | 84 | S4 |
|
||||
|
||||
**5 unique states** explored across 4 steps.
|
||||
|
||||
### Exploration statistics
|
||||
|
||||
| Metric | Value |
|
||||
|---|---|
|
||||
| States explored | 5 |
|
||||
| L0 blocks reached | 4/4 (100%) |
|
||||
| L0 regions used | 4/4 (100%) |
|
||||
| L0 loop limit | 4 (matches L1 core steps ✓) |
|
||||
| Exit block has `Terminate` | ✓ |
|
||||
| Control flow well-formed | ✓ |
|
||||
|
||||
**Result: PASS** — all 4 L0 blocks reachable, all 4 regions accessed, bounded execution verified.
|
||||
|
||||
### Why bounded model checking works here
|
||||
|
||||
Traditional bounded model checkers like CBMC must handle arbitrary C programs with unbounded loops, dynamic memory, and pointer arithmetic — requiring SAT/SMT solvers to reason about feasibility. Our DSL is fundamentally different:
|
||||
|
||||
- **Execution is bounded by construction.** The `steps: N` declaration in the core means the program always terminates in exactly N iterations. No SAT solver needed — we simply enumerate.
|
||||
- **State is finite and small.** Actor fields are typed (`u64`) and initialized with known values. With known constant inputs each step, the state at step N is fully determined by N.
|
||||
- **The state space is tractable.** For product.l1: 5 states (init + 4 steps). Even programs with many actors and fields have state counts bounded by `steps + 1`.
|
||||
|
||||
This makes exhaustive enumeration not just feasible but trivial. The "bounded" model check is actually a *complete* check — there are no states outside the bound.
|
||||
|
||||
---
|
||||
|
||||
## Verification Report
|
||||
|
||||
Running `cargo run -- verify examples/product.l1` produces:
|
||||
|
||||
```
|
||||
=== Translation Validation Report ===
|
||||
[PASS] Trace Equivalence
|
||||
[Trace Equivalence] INFO: outputs match: 4 values, final states agree across 1 actors
|
||||
[PASS] Structural Correspondence
|
||||
[Structural Correspondence] INFO: all structural invariants verified
|
||||
[PASS] Bounded Model Check
|
||||
[Bounded Model Check] INFO: explored 5 unique states across 4 steps
|
||||
[Bounded Model Check] INFO: L0 loop limit (4) matches L1 core steps
|
||||
[Bounded Model Check] INFO: all 4 L0 blocks reachable, all 4 regions accessed, bounded execution verified
|
||||
--- Field Mappings ---
|
||||
ledger.count -> ledger_state[0]
|
||||
ledger.total -> ledger_state[8]
|
||||
--- Exploration Stats ---
|
||||
states explored: 5
|
||||
L0 blocks reached: 4/4
|
||||
L0 regions used: 4/4
|
||||
Overall: PASS
|
||||
```
|
||||
|
||||
All three tools pass. The lowering is verified correct.
|
||||
|
||||
---
|
||||
|
||||
## What Else Could Be Built
|
||||
|
||||
The three tools implemented here verify the lowering through concrete execution, structural analysis, and bounded enumeration. More sophisticated techniques from the formal verification literature could extend the pipeline further. These are not built — the DSL's finite, bounded nature makes them unnecessary — but they represent natural next steps for a larger system.
|
||||
|
||||
### Symbolic Execution Engine (KLEE-inspired)
|
||||
|
||||
**What it is:** Instead of running the program with concrete values (price=7, qty=3), symbolic execution treats inputs as symbolic variables and tracks constraints along execution paths. Each branch creates a fork with the branch condition added as a constraint.
|
||||
|
||||
**What it would add:** The current verification proves correctness for the program's specific constants. Symbolic execution would prove correctness for *parameterized* inputs — e.g., that for *any* price P and quantity Q, the lowering preserves `total = total + P * Q`.
|
||||
|
||||
**Why it's not needed yet:** L1 programs have fixed inputs (leaf actions use constant expressions). There are no symbolic parameters — every execution is fully determined by the source text. Symbolic execution would become relevant if L1 gained runtime input channels.
|
||||
|
||||
### Inductive Invariant Synthesis (IC3/PDR-inspired)
|
||||
|
||||
**What it is:** IC3 (IC3/PDR) synthesizes inductive invariants — properties that hold at every reachable state and are preserved by every transition. It works backward from a safety property, finding increasingly strong invariants until it either proves the property or finds a counterexample.
|
||||
|
||||
**What it would add:** Proofs that hold across *arbitrary* step counts. Our bounded explorer verifies `steps: 4`. IC3 could prove that for `steps: N` (any N), the lowering is correct — that the correspondence between L1 and L0 is an inductive invariant of the step function.
|
||||
|
||||
**Why it's not needed yet:** L1 cores declare a fixed step count. We enumerate all states. If the step count were parameterized (e.g., `steps: N` where N is a runtime input), inductive invariant synthesis would be essential.
|
||||
|
||||
### Proof Certificate Generation (CompCert-inspired)
|
||||
|
||||
**What it is:** CompCert generates machine-checkable proof certificates that can be verified by an independent proof checker (Coq). The certificate proves that the compiled code refines the source semantics, and the proof checker confirms the certificate is valid without trusting the compiler.
|
||||
|
||||
**What it would add:** Independent verifiability. Our verification tools are part of the same codebase as the compiler — a bug in the verifier could mask a bug in the compiler. Proof certificates would allow an external tool (a small, trusted proof checker) to independently confirm correctness.
|
||||
|
||||
**Why it's not needed yet:** The system is small enough that the verification code can be audited directly. The three tools are independent of the compilation code (they don't share transformation logic). Proof certificates become valuable when the compiler is too complex for direct auditing.
|
||||
|
||||
---
|
||||
|
||||
## Pipeline Summary
|
||||
|
||||
The full verification pipeline for `examples/product.l1`:
|
||||
|
||||
```
|
||||
┌─────────────────────────────────────────────────────────────────────┐
|
||||
│ Full Verification Pipeline │
|
||||
├─────────────────────────────────────────────────────────────────────┤
|
||||
│ │
|
||||
│ 1. Parse cargo run -- examples/product.l1 │
|
||||
│ DSL source (.l1) → L1 IR │
|
||||
│ │
|
||||
│ 2. Verify L1 6 structural checks │
|
||||
│ Reference resolution, ownership, window safety, │
|
||||
│ pipeline well-formedness, buffer conservation, finiteness │
|
||||
│ │
|
||||
│ 3. Emit L1 IR → L0 IR │
|
||||
│ Actors→regions, messages→queues, pipelines→loops, │
|
||||
│ windows→loads, emit→output queue_push │
|
||||
│ │
|
||||
│ 4. Verify L0 7 concrete checks │
|
||||
│ Control flow targets, reachability, region declarations, │
|
||||
│ region bounds, access mode, queue safety, memory capacity │
|
||||
│ │
|
||||
│ 5. Translation Validation 3 verification tools │
|
||||
│ ┌─────────────────────────────────────────────┐ │
|
||||
│ │ a. Trace Equivalence (CompCert-style) │ │
|
||||
│ │ L1 interpreter vs L0 execution │ │
|
||||
│ │ Compare: final states + output values │ │
|
||||
│ │ Result: PASS (4 outputs, 1 actor) │ │
|
||||
│ ├─────────────────────────────────────────────┤ │
|
||||
│ │ b. Structural Correspondence (refinement) │ │
|
||||
│ │ L1 IR ↔ L0 IR parallel walk │ │
|
||||
│ │ 7 structural invariant checks │ │
|
||||
│ │ Result: PASS (all invariants hold) │ │
|
||||
│ ├─────────────────────────────────────────────┤ │
|
||||
│ │ c. Bounded Model Check (CBMC-style) │ │
|
||||
│ │ 5 states explored, 4/4 blocks, 4/4 regions│ │
|
||||
│ │ Result: PASS (bounded execution verified) │ │
|
||||
│ └─────────────────────────────────────────────┘ │
|
||||
│ │
|
||||
│ Overall: PASS │
|
||||
│ │
|
||||
└─────────────────────────────────────────────────────────────────────┘
|
||||
```
|
||||
|
||||
### Commands to reproduce
|
||||
|
||||
```bash
|
||||
# Full verification pipeline
|
||||
cargo run -- verify examples/product.l1
|
||||
|
||||
# Run the program (standard execution)
|
||||
cargo run -- examples/product.l1
|
||||
|
||||
# Dump all intermediate representations
|
||||
cargo run -- examples/product.l1 --dump-ir
|
||||
|
||||
# Run the REPL and verify interactively
|
||||
cargo run -- repl
|
||||
# then: :load examples/product.l1
|
||||
# then: :verify
|
||||
|
||||
# Run all tests (includes verification tool tests)
|
||||
cargo test
|
||||
```
|
||||
914
protocol_demo.html
Normal file
914
protocol_demo.html
Normal file
|
|
@ -0,0 +1,914 @@
|
|||
<!DOCTYPE html>
|
||||
<html lang="en">
|
||||
<head>
|
||||
<meta charset="utf-8">
|
||||
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=5.0">
|
||||
<title>Pipeline Walkthrough: L1 Source to x86-64</title>
|
||||
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/themes/prism-tomorrow.min.css">
|
||||
<style>
|
||||
:root {
|
||||
--bg: #1a1a2e;
|
||||
--bg-code: #16213e;
|
||||
--bg-inline: #0f3460;
|
||||
--fg: #e0e0e0;
|
||||
--fg-dim: #a0a0b0;
|
||||
--accent: #e94560;
|
||||
--accent2: #53a8b6;
|
||||
--border: #2a2a4a;
|
||||
--table-stripe: #1e1e3a;
|
||||
}
|
||||
|
||||
* { box-sizing: border-box; margin: 0; padding: 0; }
|
||||
|
||||
html {
|
||||
font-size: 16px;
|
||||
-webkit-text-size-adjust: 100%;
|
||||
scroll-behavior: smooth;
|
||||
}
|
||||
|
||||
body {
|
||||
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto,
|
||||
'Helvetica Neue', Arial, sans-serif;
|
||||
background: var(--bg);
|
||||
color: var(--fg);
|
||||
line-height: 1.7;
|
||||
padding: 1rem;
|
||||
max-width: 100%;
|
||||
overflow-x: hidden;
|
||||
overflow-wrap: break-word;
|
||||
}
|
||||
|
||||
article {
|
||||
max-width: 720px;
|
||||
margin: 0 auto;
|
||||
}
|
||||
|
||||
h1 {
|
||||
font-size: clamp(1.3rem, 4vw, 1.6rem);
|
||||
margin: 1.5rem 0 0.8rem;
|
||||
color: var(--accent);
|
||||
line-height: 1.3;
|
||||
border-bottom: 2px solid var(--accent);
|
||||
padding-bottom: 0.4rem;
|
||||
}
|
||||
|
||||
h2 {
|
||||
font-size: clamp(1.1rem, 3vw, 1.3rem);
|
||||
margin: 2rem 0 0.6rem;
|
||||
color: var(--accent2);
|
||||
border-bottom: 1px solid var(--border);
|
||||
padding-bottom: 0.3rem;
|
||||
}
|
||||
|
||||
h3 {
|
||||
font-size: clamp(1rem, 2.5vw, 1.1rem);
|
||||
margin: 1.5rem 0 0.5rem;
|
||||
color: var(--fg);
|
||||
}
|
||||
|
||||
p {
|
||||
margin: 0.6rem 0;
|
||||
}
|
||||
|
||||
strong {
|
||||
color: var(--accent2);
|
||||
}
|
||||
|
||||
a {
|
||||
color: var(--accent2);
|
||||
text-decoration: none;
|
||||
}
|
||||
|
||||
/* Code blocks */
|
||||
pre {
|
||||
background: var(--bg-code);
|
||||
border: 1px solid var(--border);
|
||||
border-radius: 6px;
|
||||
padding: 0.8rem;
|
||||
margin: 0.8rem 0;
|
||||
overflow-x: auto;
|
||||
-webkit-overflow-scrolling: touch;
|
||||
font-size: clamp(0.7rem, 1.8vw, 0.82rem);
|
||||
line-height: 1.5;
|
||||
white-space: pre;
|
||||
word-wrap: normal;
|
||||
}
|
||||
|
||||
/* Override Prism theme to match page palette */
|
||||
pre[class*="language-"],
|
||||
code[class*="language-"] {
|
||||
background: var(--bg-code) !important;
|
||||
text-shadow: none !important;
|
||||
}
|
||||
|
||||
pre code {
|
||||
background: none !important;
|
||||
padding: 0;
|
||||
border: none;
|
||||
font-size: inherit;
|
||||
color: var(--fg);
|
||||
}
|
||||
|
||||
code {
|
||||
font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Menlo',
|
||||
'Consolas', monospace;
|
||||
background: var(--bg-inline);
|
||||
padding: 0.15rem 0.35rem;
|
||||
border-radius: 3px;
|
||||
font-size: 0.88em;
|
||||
}
|
||||
|
||||
/* Pipeline flow diagram */
|
||||
.pipeline {
|
||||
margin: 1.2rem 0;
|
||||
padding: 1rem;
|
||||
border: 1px solid var(--border);
|
||||
border-radius: 8px;
|
||||
background: var(--bg-code);
|
||||
}
|
||||
|
||||
.pipeline-title {
|
||||
text-align: center;
|
||||
font-weight: 600;
|
||||
color: var(--accent2);
|
||||
margin-bottom: 1rem;
|
||||
font-size: 0.95rem;
|
||||
}
|
||||
|
||||
.pipeline-flow {
|
||||
display: flex;
|
||||
flex-direction: column;
|
||||
align-items: center;
|
||||
}
|
||||
|
||||
.pf-node {
|
||||
background: var(--bg);
|
||||
border: 1px solid var(--border);
|
||||
border-radius: 6px;
|
||||
padding: 0.45rem 1.2rem;
|
||||
text-align: center;
|
||||
font-size: 0.88rem;
|
||||
font-weight: 500;
|
||||
width: 100%;
|
||||
max-width: 14rem;
|
||||
}
|
||||
|
||||
.pf-node small {
|
||||
font-size: 0.78rem;
|
||||
color: var(--fg-dim);
|
||||
font-weight: 400;
|
||||
}
|
||||
|
||||
.pf-node.pf-final {
|
||||
border-color: var(--accent);
|
||||
color: var(--accent);
|
||||
}
|
||||
|
||||
.pf-edge {
|
||||
display: flex;
|
||||
flex-direction: column;
|
||||
align-items: center;
|
||||
padding: 0.15rem 0;
|
||||
font-size: 0.75rem;
|
||||
color: var(--fg-dim);
|
||||
font-style: italic;
|
||||
line-height: 1.2;
|
||||
}
|
||||
|
||||
.pf-edge::after {
|
||||
content: '\25BC';
|
||||
color: var(--accent2);
|
||||
font-size: 0.7rem;
|
||||
font-style: normal;
|
||||
}
|
||||
|
||||
.pf-gate {
|
||||
color: var(--accent);
|
||||
font-weight: 600;
|
||||
font-style: normal;
|
||||
}
|
||||
|
||||
/* Tables */
|
||||
.table-wrapper {
|
||||
overflow-x: auto;
|
||||
-webkit-overflow-scrolling: touch;
|
||||
margin: 0.8rem 0;
|
||||
border-radius: 6px;
|
||||
}
|
||||
|
||||
table {
|
||||
width: 100%;
|
||||
border-collapse: collapse;
|
||||
font-size: 0.88rem;
|
||||
}
|
||||
|
||||
th, td {
|
||||
border: 1px solid var(--border);
|
||||
padding: 0.5rem 0.6rem;
|
||||
text-align: left;
|
||||
}
|
||||
|
||||
th {
|
||||
background: var(--bg-code);
|
||||
font-weight: 600;
|
||||
color: var(--accent2);
|
||||
white-space: nowrap;
|
||||
}
|
||||
|
||||
td {
|
||||
white-space: normal;
|
||||
}
|
||||
|
||||
tr:nth-child(even) {
|
||||
background: var(--table-stripe);
|
||||
}
|
||||
|
||||
/* Responsive card tables on mobile */
|
||||
@media (max-width: 600px) {
|
||||
table.responsive-cards,
|
||||
table.responsive-cards thead,
|
||||
table.responsive-cards tbody,
|
||||
table.responsive-cards tr,
|
||||
table.responsive-cards th,
|
||||
table.responsive-cards td {
|
||||
display: block;
|
||||
}
|
||||
|
||||
table.responsive-cards thead {
|
||||
position: absolute;
|
||||
width: 1px;
|
||||
height: 1px;
|
||||
overflow: hidden;
|
||||
clip: rect(0, 0, 0, 0);
|
||||
}
|
||||
|
||||
table.responsive-cards tr {
|
||||
margin-bottom: 0.8rem;
|
||||
border: 1px solid var(--border);
|
||||
border-radius: 6px;
|
||||
background: var(--bg-code);
|
||||
overflow: hidden;
|
||||
}
|
||||
|
||||
table.responsive-cards tr:nth-child(even) {
|
||||
background: var(--bg-code);
|
||||
}
|
||||
|
||||
table.responsive-cards td {
|
||||
border: none;
|
||||
border-bottom: 1px solid var(--border);
|
||||
padding: 0.5rem 0.7rem;
|
||||
}
|
||||
|
||||
table.responsive-cards td:last-child {
|
||||
border-bottom: none;
|
||||
}
|
||||
|
||||
table.responsive-cards td::before {
|
||||
content: attr(data-label);
|
||||
display: block;
|
||||
font-weight: 600;
|
||||
color: var(--accent2);
|
||||
font-size: 0.75rem;
|
||||
text-transform: uppercase;
|
||||
letter-spacing: 0.03em;
|
||||
margin-bottom: 0.15rem;
|
||||
}
|
||||
}
|
||||
|
||||
/* Simple 2-col tables */
|
||||
table.simple-table th,
|
||||
table.simple-table td {
|
||||
white-space: nowrap;
|
||||
}
|
||||
|
||||
/* Lists */
|
||||
ul, ol {
|
||||
margin: 0.5rem 0 0.5rem 1.2rem;
|
||||
}
|
||||
|
||||
li {
|
||||
margin: 0.3rem 0;
|
||||
}
|
||||
|
||||
li > ul, li > ol {
|
||||
margin: 0.2rem 0 0.2rem 1rem;
|
||||
}
|
||||
|
||||
/* Horizontal rules */
|
||||
hr {
|
||||
border: none;
|
||||
border-top: 1px solid var(--border);
|
||||
margin: 2rem 0;
|
||||
}
|
||||
|
||||
/* Blockquotes */
|
||||
blockquote {
|
||||
border-left: 3px solid var(--accent);
|
||||
padding: 0.4rem 0.8rem;
|
||||
margin: 0.8rem 0;
|
||||
color: var(--fg-dim);
|
||||
background: var(--bg-code);
|
||||
border-radius: 0 4px 4px 0;
|
||||
}
|
||||
|
||||
/* Mobile adjustments */
|
||||
@media (max-width: 600px) {
|
||||
body {
|
||||
padding: 0.6rem;
|
||||
}
|
||||
|
||||
pre {
|
||||
padding: 0.6rem;
|
||||
border-radius: 4px;
|
||||
}
|
||||
|
||||
table { font-size: 0.82rem; }
|
||||
th, td { padding: 0.4rem 0.5rem; }
|
||||
}
|
||||
|
||||
/* Scroll hint for wide content on mobile */
|
||||
.scroll-hint {
|
||||
text-align: center;
|
||||
font-size: 0.72rem;
|
||||
color: var(--fg-dim);
|
||||
margin-top: -0.4rem;
|
||||
margin-bottom: 0.6rem;
|
||||
}
|
||||
|
||||
@media (min-width: 768px) {
|
||||
.scroll-hint {
|
||||
display: none;
|
||||
}
|
||||
}
|
||||
|
||||
/* Print-friendly */
|
||||
@media print {
|
||||
body { background: white; color: black; }
|
||||
pre { border-color: #ccc; background: #f8f8f8; }
|
||||
h1 { color: #333; border-color: #333; }
|
||||
h2 { color: #555; }
|
||||
}
|
||||
</style>
|
||||
</head>
|
||||
<body>
|
||||
<article>
|
||||
<h1>Pipeline Walkthrough: From L1 Source to x86-64 Execution</h1>
|
||||
<p>This document traces a single L1 program through every stage of the compiler pipeline, from DSL source text to x86-64 machine code and execution. Every intermediate representation is shown in full. Nothing is excerpted, summarized, or hidden. The purpose is to demonstrate that each transformation preserves meaning while lowering abstraction, and that verification gates between stages ensure each representation is structurally sound before the next stage consumes it.</p>
|
||||
<p>The program used is <code>examples/product.l1</code> — a product tracker that accumulates purchase quantities and costs, with an observer that emits the running total after each step.</p>
|
||||
<p><strong>Reproducibility.</strong> Every output shown in this document can be regenerated:</p>
|
||||
<pre><code class="language-bash">cargo run -- examples/product.l1 --dump-ir # all IRs + hex dump
|
||||
cargo run -- examples/product.l1 # execution output
|
||||
</code></pre>
|
||||
<h2>Pipeline Overview</h2>
|
||||
<div class="pipeline">
|
||||
<div class="pipeline-title">Compiler Pipeline</div>
|
||||
<div class="pipeline-flow">
|
||||
<div class="pf-node">DSL Source <small>(.l1)</small></div>
|
||||
<div class="pf-edge">Parse</div>
|
||||
<div class="pf-node">L1 IR</div>
|
||||
<div class="pf-edge pf-gate">Verify (L1)</div>
|
||||
<div class="pf-node">L1 IR <small>(verified)</small></div>
|
||||
<div class="pf-edge">Emit</div>
|
||||
<div class="pf-node">L0 IR</div>
|
||||
<div class="pf-edge pf-gate">Verify (L0)</div>
|
||||
<div class="pf-node">L0 IR <small>(verified)</small></div>
|
||||
<div class="pf-edge">Codegen</div>
|
||||
<div class="pf-node">x86-64 Machine Code</div>
|
||||
<div class="pf-edge"></div>
|
||||
<div class="pf-node pf-final">Execute</div>
|
||||
</div>
|
||||
</div>
|
||||
<p>Two verification gates sit between the representations. The first (L1 verification) checks structural properties of the high-level IR before lowering. The second (L0 verification) checks concrete properties of the machine-level IR before codegen. Each gate is a pass/fail decision. If verification fails, the pipeline stops — no invalid IR reaches the next stage.</p>
|
||||
<h2>The Source Program</h2>
|
||||
<p>The program models a product ledger. Each step, a purchase arrives: 3 units at price 7. The <code>ledger</code> actor multiplies price by quantity to compute the line cost, accumulates both a running unit count and a running cost total. An observer reads the total through a window and emits it as output.</p>
|
||||
<p>After 4 steps, the expected state is:</p>
|
||||
<ul>
|
||||
<li><code>count</code> = 12 (4 purchases × 3 units each)</li>
|
||||
<li><code>total</code> = 84 (4 × (7 × 3) = 4 × 21)</li>
|
||||
<li>Emitted values: [21, 42, 63, 84] — the running total after each step</li>
|
||||
</ul>
|
||||
<pre><code class="language-clike">// Product tracker: accumulates quantity and total cost from purchase events.
|
||||
//
|
||||
// Each step, a purchase of 3 units at price 7 arrives.
|
||||
// The actor multiplies price * quantity to get the line cost,
|
||||
// then adds it to the running total.
|
||||
//
|
||||
// After 4 steps:
|
||||
// count = 4 * 3 = 12
|
||||
// total = 4 * (7 * 3) = 84
|
||||
// emitted values: [21, 42, 63, 84]
|
||||
|
||||
actor ledger {
|
||||
state {
|
||||
count: u64 = 0
|
||||
total: u64 = 0
|
||||
}
|
||||
|
||||
window summary : (count, total)
|
||||
readers(report)
|
||||
|
||||
on Purchase(price: u64, qty: u64) {
|
||||
count = count + qty
|
||||
total = total + (price * qty)
|
||||
}
|
||||
}
|
||||
|
||||
leaf buy {
|
||||
process {
|
||||
forward(ledger, Purchase(7, 3))
|
||||
}
|
||||
}
|
||||
|
||||
leaf report {
|
||||
reads ledger.summary
|
||||
process {
|
||||
read(ledger.summary.total)
|
||||
emit(total)
|
||||
}
|
||||
}
|
||||
|
||||
pipeline main {
|
||||
buy -> ledger -> report
|
||||
}
|
||||
|
||||
core main {
|
||||
actors: [ledger]
|
||||
leaves: [buy, report]
|
||||
pipelines: [main]
|
||||
steps: 4
|
||||
}
|
||||
</code></pre>
|
||||
<p>The key DSL concepts at work:</p>
|
||||
<ul>
|
||||
<li><strong>Actor</strong> (<code>ledger</code>): Owns mutable state. Processes messages one at a time, serialized. State fields <code>count</code> and <code>total</code> are typed (<code>u64</code>) and initialized to zero.</li>
|
||||
<li><strong>Window</strong> (<code>summary</code>): Grants read-only access to a subset of actor state. The <code>report</code> leaf can read <code>count</code> and <code>total</code> through this window, but cannot write to them. Safety requires that readers and the actor's message handler never execute concurrently.</li>
|
||||
<li><strong>Leaves</strong> (<code>buy</code>, <code>report</code>): Stateless processors. <code>buy</code> forwards a <code>Purchase</code> message to the actor. <code>report</code> reads state through the window and emits the total as observable output.</li>
|
||||
<li><strong>Pipeline</strong> (<code>main</code>): An ordered execution chain — <code>buy → ledger → report</code>. Each step, the pipeline executes left to right: the leaf sends a message, the actor processes it, the observer reads the result.</li>
|
||||
<li><strong>Core</strong> (<code>main</code>): The execution schedule. Declares which actors, leaves, and pipelines participate, and bounds execution to exactly 4 steps.</li>
|
||||
</ul>
|
||||
<h2>L1 IR</h2>
|
||||
<p>Parsing transforms the source text into a structured, normalized intermediate representation. The parser resolves all names, validates syntax, and produces the L1 IR shown below.</p>
|
||||
<pre><code class="language-clike">actor ledger {
|
||||
state {
|
||||
count: u64 = 0
|
||||
total: u64 = 0
|
||||
}
|
||||
window summary : (count, total) readers(report)
|
||||
on Purchase(price: u64, qty: u64) { count = (count + qty); total = (total + (price * qty)) }
|
||||
}
|
||||
leaf buy { forward(ledger, Purchase(7, 3)); }
|
||||
leaf report { reads ledger.summary; read(ledger.summary.total); emit(total); }
|
||||
pipeline main { buy -> ledger -> report }
|
||||
core main {
|
||||
actors: [ledger]
|
||||
leaves: [buy, report]
|
||||
pipelines: [main]
|
||||
steps: 4
|
||||
}
|
||||
</code></pre>
|
||||
<p>What parsing resolved:</p>
|
||||
<ul>
|
||||
<li><strong>Structural normalization.</strong> The actor's state block, window declarations, and message handlers are parsed into distinct typed structures. The handler body <code>count = count + qty</code> / <code>total = total + (price * qty)</code> becomes an explicit block of assignment expressions with nested arithmetic nodes.</li>
|
||||
<li><strong>Name binding.</strong> Every reference — the leaf's <code>forward(ledger, ...)</code>, the window's <code>readers(report)</code>, the pipeline's <code>buy -> ledger -> report</code>, the core's entity lists — resolves to a declared entity. If any name were misspelled or missing, the parser would reject the program before the IR is constructed.</li>
|
||||
<li><strong>Syntactic sugar dissolved.</strong> The <code>process { ... }</code> wrapper in leaf declarations is dissolved — the IR stores the action list directly. The semicolons and braces of the display format are the IR's canonical serialization, not the source syntax.</li>
|
||||
</ul>
|
||||
<p>What is preserved: the complete program semantics. Every actor, state field, initialization value, handler, window, leaf action, pipeline ordering, and schedule parameter appears in the IR exactly as declared. Nothing is lost, nothing is added. The IR is a total, unambiguous description of the program.</p>
|
||||
<h2>L1 Verification</h2>
|
||||
<p>L1 verification is a pass/fail gate — it produces no new IR. It reads the L1 IR and checks six structural properties. If any check fails, the pipeline stops and reports the specific violation.</p>
|
||||
<p>The checks, mapped to the spec's four property categories:</p>
|
||||
<div class="table-wrapper">
|
||||
<table class="responsive-cards">
|
||||
<thead>
|
||||
<tr>
|
||||
<th>Property</th>
|
||||
<th>Check</th>
|
||||
<th>What it catches</th>
|
||||
</tr>
|
||||
</thead>
|
||||
<tbody><tr>
|
||||
<td data-label="Property"><strong>Safety</strong></td>
|
||||
<td data-label="Check">Ref resolution</td>
|
||||
<td data-label="What it catches">Every name in cores, pipelines, windows, and leaf actions resolves to a declared actor, leaf, or pipeline. Catches dangling references — a <code>forward</code> to a non-existent actor, a window naming a non-existent reader, a pipeline referencing an undeclared entity.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Property"><strong>Safety</strong></td>
|
||||
<td data-label="Check">Exclusive ownership</td>
|
||||
<td data-label="What it catches">Each actor and leaf belongs to exactly one core. Prevents the same entity from being claimed by two different execution contexts.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Property"><strong>Safety</strong></td>
|
||||
<td data-label="Check">Window separation</td>
|
||||
<td data-label="What it catches">Window readers must be leaves (not actors). Readers must be in the same core as the actor. A leaf that both reads a window on an actor AND forwards messages to that same actor is rejected — this would create a read-write hazard.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Property"><strong>Consistency</strong></td>
|
||||
<td data-label="Check">Pipeline well-formedness</td>
|
||||
<td data-label="What it catches">Every pipeline has at least 2 stages. No stage appears twice within a pipeline (which would indicate a cycle).</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Property"><strong>Liveness</strong></td>
|
||||
<td data-label="Check">Buffer conservation</td>
|
||||
<td data-label="What it catches">Every leaf has at least one action (forward, read, or emit). A leaf with no actions would mean its input is never consumed.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Property"><strong>Resource bound</strong></td>
|
||||
<td data-label="Check">Finiteness</td>
|
||||
<td data-label="What it catches">Every core has <code>steps > 0</code>. Cross-pipeline cycles are detected via topological sort — if the entity ordering across all pipelines contains a cycle, the program cannot make progress and is rejected.</td>
|
||||
</tr>
|
||||
</tbody></table>
|
||||
</div>
|
||||
<p>By the time verification passes, the L1 IR has been proven structurally sound: all references resolve, ownership is exclusive, windows are safe, pipelines are well-formed, buffers are consumed, and execution is bounded. The emit stage can trust its input completely.</p>
|
||||
<h2>L0 IR</h2>
|
||||
<p>Emission transforms the verified L1 IR into L0 IR — the machine-level representation. This is the most important transformation in the pipeline. High-level concepts dissolve into explicit, low-level operations over named memory regions.</p>
|
||||
<pre><code>=== Regions ===
|
||||
region ledger_state : 16 bytes, rw, state
|
||||
region ledger_purchase_queue : 272 bytes, rw, queue
|
||||
region step_counter : 8 bytes, rw, control
|
||||
region output : 48 bytes, rw, output
|
||||
=== Blocks ===
|
||||
entry:
|
||||
r0 = imm #0
|
||||
store.64 ledger_state[0], r0
|
||||
store.64 ledger_state[8], r0
|
||||
store.64 step_counter[0], r0
|
||||
store.64 output[0], r0
|
||||
jump -> loop_check
|
||||
loop_check:
|
||||
r1 = load.64 step_counter[0]
|
||||
r2 = imm #4
|
||||
r3 = cmp.lt r1, r2
|
||||
branch r3 -> step, exit
|
||||
step:
|
||||
r4 = imm #7
|
||||
queue_push ledger_purchase_queue, r4
|
||||
r5 = imm #3
|
||||
queue_push ledger_purchase_queue, r5
|
||||
r6 = queue_pop ledger_purchase_queue
|
||||
r7 = queue_pop ledger_purchase_queue
|
||||
r8 = load.64 ledger_state[0]
|
||||
r9 = add r8, r7
|
||||
store.64 ledger_state[0], r9
|
||||
r10 = load.64 ledger_state[8]
|
||||
r11 = mul r6, r7
|
||||
r12 = add r10, r11
|
||||
store.64 ledger_state[8], r12
|
||||
r13 = load.64 ledger_state[8]
|
||||
r14 = load.64 ledger_state[8]
|
||||
queue_push output, r14
|
||||
r15 = load.64 step_counter[0]
|
||||
r16 = add r15, #1
|
||||
store.64 step_counter[0], r16
|
||||
jump -> loop_check
|
||||
exit:
|
||||
terminate
|
||||
</code></pre>
|
||||
<p class="scroll-hint">Swipe to scroll wide content</p>
|
||||
<p>Here is what happened to each L1 concept:</p>
|
||||
<p><strong>Actors became regions.</strong> The actor <code>ledger</code> with state fields <code>count: u64 = 0</code> and <code>total: u64 = 0</code> became <code>region ledger_state : 16 bytes, rw, state</code> — two 8-byte fields at offsets 0 and 8. The actor's identity dissolved. What remains is a named, sized, access-controlled memory region. Loads and stores name this region explicitly: <code>store.64 ledger_state[0]</code> writes the count field, <code>store.64 ledger_state[8]</code> writes the total field.</p>
|
||||
<p><strong>Messages became queues.</strong> The <code>forward(ledger, Purchase(7, 3))</code> in the <code>buy</code> leaf became two <code>queue_push</code> operations — one for each argument (price=7, qty=3) — into <code>region ledger_purchase_queue : 272 bytes, rw, queue</code>. The actor's <code>on Purchase(price, qty)</code> handler became two <code>queue_pop</code> operations that retrieve those values, followed by arithmetic on the state region. The queue region is a ring buffer: 16 bytes for head and tail pointers, plus capacity for 16 messages × 2 arguments × 8 bytes = 256 bytes of data.</p>
|
||||
<p><strong>The pipeline became a loop.</strong> The <code>steps: 4</code> in the core schedule became <code>region step_counter : 8 bytes, rw, control</code>, a <code>loop_check</code> block with <code>cmp.lt</code> against immediate #4, and a conditional branch. Each iteration walks the pipeline stages in order (buy's forward → ledger's handler → report's read and emit), then increments the step counter and jumps back to <code>loop_check</code>.</p>
|
||||
<p><strong>Window reads became loads.</strong> The <code>report</code> leaf's <code>read(ledger.summary.total)</code> became <code>r13 = load.64 ledger_state[8]</code> — a direct load from the state region at the total field's offset. The window abstraction is gone; what remains is a memory access that the verifier already proved safe.</p>
|
||||
<p><strong>Emit became a queue push.</strong> The <code>emit(total)</code> became <code>queue_push output, r14</code> — pushing the loaded total value into <code>region output : 48 bytes, rw, output</code>. The output region is sized for exactly 4 steps: 16 bytes header + 4 × 8 bytes data = 48 bytes.</p>
|
||||
<p><strong>Everything became explicit.</strong> Every load, every store, every register assignment, every comparison, every branch is visible. There is no implicit state, no hidden control flow, no magic. The L0 IR is a total description of what the machine will do.</p>
|
||||
<p>Walking through the blocks:</p>
|
||||
<ul>
|
||||
<li><strong><code>entry</code></strong>: Loads immediate 0, stores it to both state fields (<code>ledger_state[0]</code> and <code>[8]</code>), the step counter, and the output head. Jumps to <code>loop_check</code>.</li>
|
||||
<li><strong><code>loop_check</code></strong>: Loads the step counter, loads the bound (4), compares. Branches to <code>step</code> if counter < 4, otherwise to <code>exit</code>.</li>
|
||||
<li><strong><code>step</code></strong>: Executes one complete pipeline iteration. Pushes price (7) and qty (3) to the queue, pops them back (simulating message delivery), loads count, adds qty, stores count. Loads total, multiplies price × qty, adds to total, stores total. Reads total through the window, pushes it to output. Increments step counter. Jumps back to <code>loop_check</code>.</li>
|
||||
<li><strong><code>exit</code></strong>: Terminates execution.</li>
|
||||
</ul>
|
||||
<h2>L0 Verification</h2>
|
||||
<p>L0 verification checks the concrete IR after emission, before codegen. It collects all errors (unlike L1 verification which stops at the first). The checks:</p>
|
||||
<div class="table-wrapper">
|
||||
<table class="responsive-cards">
|
||||
<thead>
|
||||
<tr>
|
||||
<th>Property</th>
|
||||
<th>Check</th>
|
||||
<th>What it catches</th>
|
||||
</tr>
|
||||
</thead>
|
||||
<tbody><tr>
|
||||
<td data-label="Property"><strong>Safety</strong></td>
|
||||
<td data-label="Check">Control flow targets</td>
|
||||
<td data-label="What it catches">Every <code>branch</code> and <code>jump</code> names a block that exists. A dangling target would mean the program jumps into the void.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Property"><strong>Safety</strong></td>
|
||||
<td data-label="Check">Block reachability</td>
|
||||
<td data-label="What it catches">Every block is reachable from the entry block (the first block) via BFS over control flow edges. Unreachable blocks are dead code that may contain invalid operations.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Property"><strong>Safety</strong></td>
|
||||
<td data-label="Check">Region declarations</td>
|
||||
<td data-label="What it catches">Every <code>load</code> and <code>store</code> names a region that is declared in the regions list. An undeclared region reference would mean accessing memory that doesn't exist.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Property"><strong>Safety</strong></td>
|
||||
<td data-label="Check">Region bounds</td>
|
||||
<td data-label="What it catches">Every memory access satisfies <code>offset + access_size ≤ region_size</code>. Out-of-bounds access would read or write past the region boundary.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Property"><strong>Safety</strong></td>
|
||||
<td data-label="Check">Access mode</td>
|
||||
<td data-label="What it catches">Stores to read-only regions are rejected. The access mode is a compile-time invariant that codegen can rely on.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Property"><strong>Resource bound</strong></td>
|
||||
<td data-label="Check">Queue safety</td>
|
||||
<td data-label="What it catches"><code>queue_push</code> and <code>queue_pop</code> only operate on regions with queue or output kind. Using queue operations on a state or control region would corrupt its layout.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td data-label="Property"><strong>Resource bound</strong></td>
|
||||
<td data-label="Check">Memory capacity</td>
|
||||
<td data-label="What it catches">Total memory is bounded — every region has a fixed size, and all sizes are known at compile time. The <code>total_memory()</code> utility sums all region sizes (in this program: 16 + 272 + 8 + 48 = 344 bytes).</td>
|
||||
</tr>
|
||||
</tbody></table>
|
||||
</div>
|
||||
<p>After L0 verification passes, the IR is proven safe for codegen: all control flow is valid, all memory accesses are in-bounds, all access modes are respected, and all queue operations target the correct region kinds.</p>
|
||||
<h2>x86-64 Machine Code</h2>
|
||||
<p>Codegen translates the verified L0 IR into x86-64 machine code. The translation is mechanical: each L0 operation maps to a small, predictable cluster of x86 instructions.</p>
|
||||
<h3>Raw hex dump</h3>
|
||||
<pre><code>53 55 41 54 41 55 41 56 41 57 4c 8b a7 00 00 00
|
||||
00 4c 8b af 08 00 00 00 4c 8b b7 10 00 00 00 4c
|
||||
8b bf 18 00 00 00 48 b8 00 00 00 00 00 00 00 00
|
||||
49 89 84 24 00 00 00 00 49 89 84 24 08 00 00 00
|
||||
49 89 86 00 00 00 00 49 89 87 00 00 00 00 e9 00
|
||||
00 00 00 49 8b 8e 00 00 00 00 48 ba 04 00 00 00
|
||||
00 00 00 00 48 39 d1 0f 9c c3 48 0f b6 db 48 85
|
||||
db 0f 85 05 00 00 00 e9 64 01 00 00 48 be 07 00
|
||||
00 00 00 00 00 00 49 8b bd 00 00 00 00 48 89 fd
|
||||
48 b9 03 00 00 00 00 00 00 00 48 c1 e5 03 48 81
|
||||
c5 10 00 00 00 4c 01 ed 48 89 75 00 48 81 c7 01
|
||||
00 00 00 49 89 bd 00 00 00 00 49 b8 03 00 00 00
|
||||
00 00 00 00 49 8b bd 00 00 00 00 48 89 fd 48 b9
|
||||
03 00 00 00 00 00 00 00 48 c1 e5 03 48 81 c5 10
|
||||
00 00 00 4c 01 ed 4c 89 45 00 48 81 c7 01 00 00
|
||||
00 49 89 bd 00 00 00 00 49 8b bd 08 00 00 00 48
|
||||
89 fd 48 c1 e5 03 48 81 c5 10 00 00 00 4c 01 ed
|
||||
4c 8b 4d 00 48 81 c7 01 00 00 00 49 89 bd 08 00
|
||||
00 00 49 8b bd 08 00 00 00 48 89 fd 48 c1 e5 03
|
||||
48 81 c5 10 00 00 00 4c 01 ed 4c 8b 55 00 48 81
|
||||
c7 01 00 00 00 49 89 bd 08 00 00 00 4d 8b 9c 24
|
||||
00 00 00 00 4c 89 d8 4c 01 d0 49 89 84 24 00 00
|
||||
00 00 49 8b 8c 24 08 00 00 00 4c 89 ca 49 0f af
|
||||
d2 48 89 cb 48 01 d3 49 89 9c 24 08 00 00 00 49
|
||||
8b b4 24 08 00 00 00 4d 8b 84 24 08 00 00 00 49
|
||||
8b bf 00 00 00 00 48 89 fd 48 b9 03 00 00 00 00
|
||||
00 00 00 48 c1 e5 03 48 81 c5 10 00 00 00 4c 01
|
||||
fd 4c 89 45 00 48 81 c7 01 00 00 00 49 89 bf 00
|
||||
00 00 00 4d 8b 8e 00 00 00 00 4d 89 ca 49 81 c2
|
||||
01 00 00 00 4d 89 96 00 00 00 00 e9 73 fe ff ff
|
||||
41 5f 41 5e 41 5d 41 5c 5d 5b c3
|
||||
</code></pre>
|
||||
<p>491 bytes of x86-64 machine code.</p>
|
||||
<h3>Annotated disassembly</h3>
|
||||
<p>The generated function follows the System V AMD64 calling convention. It receives a single argument in <code>rdi</code>: a pointer to an array of region base addresses. Region bases are loaded into dedicated registers at entry:</p>
|
||||
<div class="table-wrapper">
|
||||
<table class="simple-table">
|
||||
<thead>
|
||||
<tr>
|
||||
<th>Register</th>
|
||||
<th>Region</th>
|
||||
</tr>
|
||||
</thead>
|
||||
<tbody><tr>
|
||||
<td>R12</td>
|
||||
<td><code>ledger_state</code> (16 bytes, state)</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>R13</td>
|
||||
<td><code>ledger_purchase_queue</code> (272 bytes, queue)</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>R14</td>
|
||||
<td><code>step_counter</code> (8 bytes, control)</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td>R15</td>
|
||||
<td><code>output</code> (48 bytes, output)</td>
|
||||
</tr>
|
||||
</tbody></table>
|
||||
</div>
|
||||
<p>SSA registers are allocated from the remaining pool: RAX, RCX, RDX, RBX, RSI, R8–R11. RBP and RDI are used as scratch temporaries for queue address computation.</p>
|
||||
<pre><code class="language-nasm">; === prologue: save callee-saved registers ===
|
||||
0x00: push rbx ; save callee-saved
|
||||
0x01: push rbp
|
||||
0x02: push r12
|
||||
0x04: push r13
|
||||
0x06: push r14
|
||||
0x08: push r15
|
||||
|
||||
; === load region base pointers from rdi array ===
|
||||
0x0a: mov r12, [rdi+0x00] ; r12 = &ledger_state
|
||||
0x11: mov r13, [rdi+0x08] ; r13 = &ledger_purchase_queue
|
||||
0x18: mov r14, [rdi+0x10] ; r14 = &step_counter
|
||||
0x1f: mov r15, [rdi+0x18] ; r15 = &output
|
||||
|
||||
; === entry block: initialize regions ===
|
||||
; r0 = imm #0
|
||||
0x26: movabs rax, 0x0 ; rax = 0 (r0)
|
||||
|
||||
; store.64 ledger_state[0], r0 — count = 0
|
||||
0x30: mov [r12+0x00], rax
|
||||
|
||||
; store.64 ledger_state[8], r0 — total = 0
|
||||
0x38: mov [r12+0x08], rax
|
||||
|
||||
; store.64 step_counter[0], r0 — step = 0
|
||||
0x40: mov [r14+0x00], rax
|
||||
|
||||
; store.64 output[0], r0 — output head = 0
|
||||
0x47: mov [r15+0x00], rax
|
||||
|
||||
; jump -> loop_check
|
||||
0x4e: jmp 0x53 ; fall through to loop_check
|
||||
|
||||
; === loop_check block: compare step counter to bound ===
|
||||
; r1 = load.64 step_counter[0]
|
||||
0x53: mov rcx, [r14+0x00] ; rcx = step counter (r1)
|
||||
|
||||
; r2 = imm #4
|
||||
0x5a: movabs rdx, 0x4 ; rdx = 4 (r2)
|
||||
|
||||
; r3 = cmp.lt r1, r2
|
||||
0x64: cmp rcx, rdx ; compare step < 4
|
||||
0x67: setl bl ; bl = 1 if less
|
||||
0x6a: movzx rbx, bl ; rbx = zero-extended result (r3)
|
||||
|
||||
; branch r3 -> step, exit
|
||||
0x6e: test rbx, rbx ; test condition
|
||||
0x71: jne 0x7c ; if true → step block
|
||||
0x77: jmp 0x1e0 ; if false → exit block
|
||||
|
||||
; === step block: pipeline execution ===
|
||||
|
||||
; --- leaf buy: forward(ledger, Purchase(7, 3)) ---
|
||||
; r4 = imm #7
|
||||
0x7c: movabs rsi, 0x7 ; rsi = 7, the price (r4)
|
||||
|
||||
; queue_push ledger_purchase_queue, r4
|
||||
; load head, compute slot address, store value, increment head
|
||||
0x86: mov rdi, [r13+0x00] ; rdi = queue head
|
||||
0x8d: mov rbp, rdi ; rbp = head (working copy)
|
||||
0x90: movabs rcx, 0x3 ; rcx = 3 (modulo constant, unused here)
|
||||
0x9a: shl rbp, 0x3 ; rbp = head * 8
|
||||
0x9e: add rbp, 0x10 ; rbp += 16 (skip header)
|
||||
0xa5: add rbp, r13 ; rbp = &queue[head] absolute
|
||||
0xa8: mov [rbp+0x00], rsi ; queue[head] = 7 (price)
|
||||
0xac: add rdi, 0x1 ; head++
|
||||
0xb3: mov [r13+0x00], rdi ; store updated head
|
||||
|
||||
; r5 = imm #3
|
||||
0xba: movabs r8, 0x3 ; r8 = 3, the quantity (r5)
|
||||
|
||||
; queue_push ledger_purchase_queue, r5
|
||||
0xc4: mov rdi, [r13+0x00] ; rdi = queue head
|
||||
0xcb: mov rbp, rdi
|
||||
0xce: movabs rcx, 0x3
|
||||
0xd8: shl rbp, 0x3
|
||||
0xdc: add rbp, 0x10
|
||||
0xe3: add rbp, r13
|
||||
0xe6: mov [rbp+0x00], r8 ; queue[head] = 3 (qty)
|
||||
0xea: add rdi, 0x1
|
||||
0xf1: mov [r13+0x00], rdi ; store updated head
|
||||
|
||||
; --- actor ledger: queue_pop × 2, then handler body ---
|
||||
; r6 = queue_pop ledger_purchase_queue (price)
|
||||
0xf8: mov rdi, [r13+0x08] ; rdi = queue tail
|
||||
0xff: mov rbp, rdi
|
||||
0x102: shl rbp, 0x3
|
||||
0x106: add rbp, 0x10
|
||||
0x10d: add rbp, r13
|
||||
0x110: mov r9, [rbp+0x00] ; r9 = popped price value (r6)
|
||||
0x114: add rdi, 0x1 ; tail++
|
||||
0x11b: mov [r13+0x08], rdi ; store updated tail
|
||||
|
||||
; r7 = queue_pop ledger_purchase_queue (qty)
|
||||
0x122: mov rdi, [r13+0x08] ; rdi = queue tail
|
||||
0x129: mov rbp, rdi
|
||||
0x12c: shl rbp, 0x3
|
||||
0x130: add rbp, 0x10
|
||||
0x137: add rbp, r13
|
||||
0x13a: mov r10, [rbp+0x00] ; r10 = popped qty value (r7)
|
||||
0x13e: add rdi, 0x1
|
||||
0x145: mov [r13+0x08], rdi
|
||||
|
||||
; --- handler: count = count + qty ---
|
||||
; r8 = load.64 ledger_state[0] — load count
|
||||
0x14c: mov r11, [r12+0x00] ; r11 = count (r8)
|
||||
|
||||
; r9 = add r8, r7 — count + qty
|
||||
0x154: mov rax, r11 ; rax = count
|
||||
0x157: add rax, r10 ; rax = count + qty (r9)
|
||||
|
||||
; store.64 ledger_state[0], r9 — store updated count
|
||||
0x15a: mov [r12+0x00], rax
|
||||
|
||||
; --- handler: total = total + (price * qty) ---
|
||||
; r10 = load.64 ledger_state[8] — load total
|
||||
0x162: mov rcx, [r12+0x08] ; rcx = total (r10)
|
||||
|
||||
; r11 = mul r6, r7 — price * qty
|
||||
0x16a: mov rdx, r9 ; rdx = price
|
||||
0x16d: imul rdx, r10 ; rdx = price * qty (r11)
|
||||
|
||||
; r12 = add r10, r11 — total + (price * qty)
|
||||
0x171: mov rbx, rcx ; rbx = total
|
||||
0x174: add rbx, rdx ; rbx = total + price*qty (r12)
|
||||
|
||||
; store.64 ledger_state[8], r12 — store updated total
|
||||
0x177: mov [r12+0x08], rbx
|
||||
|
||||
; --- leaf report: read + emit ---
|
||||
; r13 = load.64 ledger_state[8] — read total through window
|
||||
0x17f: mov rsi, [r12+0x08] ; rsi = total (r13)
|
||||
|
||||
; r14 = load.64 ledger_state[8] — emit expression: load total
|
||||
0x187: mov r8, [r12+0x08] ; r8 = total (r14)
|
||||
|
||||
; queue_push output, r14 — emit(total)
|
||||
0x18f: mov rdi, [r15+0x00] ; rdi = output head
|
||||
0x196: mov rbp, rdi
|
||||
0x199: movabs rcx, 0x3
|
||||
0x1a3: shl rbp, 0x3
|
||||
0x1a7: add rbp, 0x10
|
||||
0x1ae: add rbp, r15 ; rbp = &output[head]
|
||||
0x1b1: mov [rbp+0x00], r8 ; output[head] = total
|
||||
0x1b5: add rdi, 0x1
|
||||
0x1bc: mov [r15+0x00], rdi ; head++
|
||||
|
||||
; --- step counter increment ---
|
||||
; r15 = load.64 step_counter[0]
|
||||
0x1c3: mov r9, [r14+0x00] ; r9 = step counter (r15)
|
||||
|
||||
; r16 = add r15, #1
|
||||
0x1ca: mov r10, r9
|
||||
0x1cd: add r10, 0x1 ; r10 = step + 1 (r16)
|
||||
|
||||
; store.64 step_counter[0], r16
|
||||
0x1d4: mov [r14+0x00], r10 ; store updated step counter
|
||||
|
||||
; jump -> loop_check
|
||||
0x1db: jmp 0x53 ; back to loop_check
|
||||
|
||||
; === exit block: terminate ===
|
||||
; restore callee-saved registers and return
|
||||
0x1e0: pop r15
|
||||
0x1e2: pop r14
|
||||
0x1e4: pop r13
|
||||
0x1e6: pop r12
|
||||
0x1e8: pop rbp
|
||||
0x1e9: pop rbx
|
||||
0x1ea: ret
|
||||
</code></pre>
|
||||
<p class="scroll-hint">Swipe to scroll wide content</p>
|
||||
<p><strong>Codegen strategy:</strong></p>
|
||||
<ul>
|
||||
<li><p><strong>Regions become register-indirect memory.</strong> Each region's base address is loaded into a dedicated callee-saved register (R12–R15) at function entry. All loads and stores use these base registers with constant displacements: <code>mov [r12+0x08], rax</code> writes to <code>ledger_state</code> at offset 8 (the <code>total</code> field). Named regions preserve aliasing knowledge all the way to machine code — the codegen knows that <code>[r12+0x00]</code> and <code>[r14+0x00]</code> can never alias because they point to different regions.</p>
|
||||
</li>
|
||||
<li><p><strong>Block structure maps to jump targets.</strong> The L0 blocks (<code>entry</code>, <code>loop_check</code>, <code>step</code>, <code>exit</code>) become contiguous instruction sequences with <code>jmp</code>/<code>jne</code> instructions connecting them. Jump targets are resolved in a two-pass fixup: the first pass emits placeholder offsets, the second patches them once all block positions are known.</p>
|
||||
</li>
|
||||
<li><p><strong>Queue operations translate to ring buffer indexing.</strong> Each <code>queue_push</code> becomes: load head from <code>[base+0]</code>, compute slot address as <code>base + 16 + head*8</code>, store the value, increment head, store head back. <code>queue_pop</code> does the same with tail at <code>[base+8]</code>. The pattern is identical every time — five instructions for each queue operation.</p>
|
||||
</li>
|
||||
<li><p><strong>Arithmetic is direct.</strong> <code>add</code> → <code>add</code>, <code>mul</code> → <code>imul</code>. The move-then-operate pattern (<code>mov rax, r11; add rax, r10</code>) is the codegen's way of preserving SSA semantics in a register machine: the destination register is first loaded with the left operand, then the operation is applied with the right operand.</p>
|
||||
</li>
|
||||
<li><p><strong>Comparisons use <code>setcc</code> + <code>movzx</code>.</strong> The <code>cmp.lt</code> operation becomes <code>cmp rcx, rdx; setl bl; movzx rbx, bl</code> — compare, set a byte flag, zero-extend to 64 bits. The result feeds into <code>test rbx, rbx; jne</code> for the conditional branch.</p>
|
||||
</li>
|
||||
</ul>
|
||||
<h2>Execution</h2>
|
||||
<p>Running the program produces:</p>
|
||||
<pre><code>Execution complete.
|
||||
step_counter[0] = 4
|
||||
output[0] = 4
|
||||
ledger_state[0] = 12
|
||||
ledger_purchase_queue[0] = 8
|
||||
output values: [21, 42, 63, 84]
|
||||
</code></pre>
|
||||
<p>Interpreting the results:</p>
|
||||
<ul>
|
||||
<li><strong><code>ledger_state[0] = 12</code></strong>: The <code>count</code> field. 4 steps × 3 units per step = 12. Correct.</li>
|
||||
<li><strong><code>step_counter[0] = 4</code></strong>: The loop ran exactly 4 iterations. Correct.</li>
|
||||
<li><strong><code>ledger_purchase_queue[0] = 8</code></strong>: The queue head advanced 8 positions (2 pushes per step × 4 steps). Correct.</li>
|
||||
<li><strong><code>output[0] = 4</code></strong>: The output head — 4 values were emitted. Correct.</li>
|
||||
<li><strong><code>output values: [21, 42, 63, 84]</code></strong>: The running total after each step:<ul>
|
||||
<li>Step 1: 0 + (7 × 3) = 21</li>
|
||||
<li>Step 2: 21 + 21 = 42</li>
|
||||
<li>Step 3: 42 + 21 = 63</li>
|
||||
<li>Step 4: 63 + 21 = 84</li>
|
||||
</ul>
|
||||
</li>
|
||||
</ul>
|
||||
<p>Every value matches the program's intent. The total field (at <code>ledger_state[8]</code>, not shown in the summary line but readable from the region) holds 84. The loop from source intent to machine execution is closed.</p>
|
||||
<h2>Closing</h2>
|
||||
<p>This walkthrough traced a single program through six transformations: parse, L1 verify, emit, L0 verify, codegen, execute. At each stage, the representation was shown in full — no excerpts, no elisions.</p>
|
||||
<p>Three properties of the pipeline emerge from this trace. First, every representation is total and inspectable. The L1 IR is a complete, unambiguous description of the program. The L0 IR is a complete, explicit description of the execution. The machine code is a complete, executable binary. Nothing is hidden at any layer. Second, verification gates between representations mean each stage can trust its input. The emitter knows all references resolve because L1 verification proved it. The codegen knows all memory accesses are in-bounds because L0 verification proved it. Trust is replaced by proof.</p>
|
||||
<p>Third, the transformations are mechanical and traceable. Every L0 instruction maps back to an L1 concept. Every x86 instruction maps back to an L0 operation. No stage introduces decisions the previous stage didn't authorize. The machine code is a direct consequence of the source program, with every intermediate step visible and verifiable.</p>
|
||||
|
||||
</article>
|
||||
<script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/prism.min.js"></script>
|
||||
<script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/components/prism-nasm.min.js"></script>
|
||||
<script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/components/prism-bash.min.js"></script>
|
||||
</body>
|
||||
</html>
|
||||
516
protocol_demo.md
Normal file
516
protocol_demo.md
Normal file
|
|
@ -0,0 +1,516 @@
|
|||
# Pipeline Walkthrough: From L1 Source to x86-64 Execution
|
||||
|
||||
This document traces a single L1 program through every stage of the compiler pipeline, from DSL source text to x86-64 machine code and execution. Every intermediate representation is shown in full. Nothing is excerpted, summarized, or hidden. The purpose is to demonstrate that each transformation preserves meaning while lowering abstraction, and that verification gates between stages ensure each representation is structurally sound before the next stage consumes it.
|
||||
|
||||
The program used is `examples/product.l1` — a product tracker that accumulates purchase quantities and costs, with an observer that emits the running total after each step.
|
||||
|
||||
**Reproducibility.** Every output shown in this document can be regenerated:
|
||||
|
||||
```
|
||||
cargo run -- examples/product.l1 --dump-ir # all IRs + hex dump
|
||||
cargo run -- examples/product.l1 # execution output
|
||||
```
|
||||
|
||||
## Pipeline Overview
|
||||
|
||||
```
|
||||
┌─────────────────────────────────────────────────────────┐
|
||||
│ Compiler Pipeline │
|
||||
└─────────────────────────────────────────────────────────┘
|
||||
|
||||
┌──────────┐ ┌───────┐ ┌───────┐ ┌──────────┐ ┌───────┐
|
||||
│ DSL │ │ L1 │ │ L1 │ │ L0 │ │ L0 │
|
||||
│ Source │─────▶│ IR │─────▶│ IR │─────▶│ IR │─────▶│ IR │
|
||||
│ (.l1) │ │ │ │(verified) │ │ │(verified)
|
||||
└──────────┘ └───────┘ └───────┘ └──────────┘ └───────┘
|
||||
Parse Verify(L1) Emit Verify(L0)
|
||||
│
|
||||
▼
|
||||
┌───────────┐
|
||||
┌──────────┐ ┌───────────┐ │ Codegen │
|
||||
│ Execute │◀─────│ x86-64 │◀───────────│ │
|
||||
│ │ │ Machine │ └───────────┘
|
||||
└──────────┘ │ Code │
|
||||
└───────────┘
|
||||
```
|
||||
|
||||
Two verification gates sit between the representations. The first (L1 verification) checks structural properties of the high-level IR before lowering. The second (L0 verification) checks concrete properties of the machine-level IR before codegen. Each gate is a pass/fail decision. If verification fails, the pipeline stops — no invalid IR reaches the next stage.
|
||||
|
||||
## The Source Program
|
||||
|
||||
The program models a product ledger. Each step, a purchase arrives: 3 units at price 7. The `ledger` actor multiplies price by quantity to compute the line cost, accumulates both a running unit count and a running cost total. An observer reads the total through a window and emits it as output.
|
||||
|
||||
After 4 steps, the expected state is:
|
||||
- `count` = 12 (4 purchases × 3 units each)
|
||||
- `total` = 84 (4 × (7 × 3) = 4 × 21)
|
||||
- Emitted values: [21, 42, 63, 84] — the running total after each step
|
||||
|
||||
```l1
|
||||
// Product tracker: accumulates quantity and total cost from purchase events.
|
||||
//
|
||||
// Each step, a purchase of 3 units at price 7 arrives.
|
||||
// The actor multiplies price * quantity to get the line cost,
|
||||
// then adds it to the running total.
|
||||
//
|
||||
// After 4 steps:
|
||||
// count = 4 * 3 = 12
|
||||
// total = 4 * (7 * 3) = 84
|
||||
// emitted values: [21, 42, 63, 84]
|
||||
|
||||
actor ledger {
|
||||
state {
|
||||
count: u64 = 0
|
||||
total: u64 = 0
|
||||
}
|
||||
|
||||
window summary : (count, total)
|
||||
readers(report)
|
||||
|
||||
on Purchase(price: u64, qty: u64) {
|
||||
count = count + qty
|
||||
total = total + (price * qty)
|
||||
}
|
||||
}
|
||||
|
||||
leaf buy {
|
||||
process {
|
||||
forward(ledger, Purchase(7, 3))
|
||||
}
|
||||
}
|
||||
|
||||
leaf report {
|
||||
reads ledger.summary
|
||||
process {
|
||||
read(ledger.summary.total)
|
||||
emit(total)
|
||||
}
|
||||
}
|
||||
|
||||
pipeline main {
|
||||
buy -> ledger -> report
|
||||
}
|
||||
|
||||
core main {
|
||||
actors: [ledger]
|
||||
leaves: [buy, report]
|
||||
pipelines: [main]
|
||||
steps: 4
|
||||
}
|
||||
```
|
||||
|
||||
The key DSL concepts at work:
|
||||
|
||||
- **Actor** (`ledger`): Owns mutable state. Processes messages one at a time, serialized. State fields `count` and `total` are typed (`u64`) and initialized to zero.
|
||||
- **Window** (`summary`): Grants read-only access to a subset of actor state. The `report` leaf can read `count` and `total` through this window, but cannot write to them. Safety requires that readers and the actor's message handler never execute concurrently.
|
||||
- **Leaves** (`buy`, `report`): Stateless processors. `buy` forwards a `Purchase` message to the actor. `report` reads state through the window and emits the total as observable output.
|
||||
- **Pipeline** (`main`): An ordered execution chain — `buy → ledger → report`. Each step, the pipeline executes left to right: the leaf sends a message, the actor processes it, the observer reads the result.
|
||||
- **Core** (`main`): The execution schedule. Declares which actors, leaves, and pipelines participate, and bounds execution to exactly 4 steps.
|
||||
|
||||
## L1 IR
|
||||
|
||||
Parsing transforms the source text into a structured, normalized intermediate representation. The parser resolves all names, validates syntax, and produces the L1 IR shown below.
|
||||
|
||||
```
|
||||
actor ledger {
|
||||
state {
|
||||
count: u64 = 0
|
||||
total: u64 = 0
|
||||
}
|
||||
window summary : (count, total) readers(report)
|
||||
on Purchase(price: u64, qty: u64) { count = (count + qty); total = (total + (price * qty)) }
|
||||
}
|
||||
leaf buy { forward(ledger, Purchase(7, 3)); }
|
||||
leaf report { reads ledger.summary; read(ledger.summary.total); emit(total); }
|
||||
pipeline main { buy -> ledger -> report }
|
||||
core main {
|
||||
actors: [ledger]
|
||||
leaves: [buy, report]
|
||||
pipelines: [main]
|
||||
steps: 4
|
||||
}
|
||||
```
|
||||
|
||||
What parsing resolved:
|
||||
|
||||
- **Structural normalization.** The actor's state block, window declarations, and message handlers are parsed into distinct typed structures. The handler body `count = count + qty` / `total = total + (price * qty)` becomes an explicit block of assignment expressions with nested arithmetic nodes.
|
||||
- **Name binding.** Every reference — the leaf's `forward(ledger, ...)`, the window's `readers(report)`, the pipeline's `buy -> ledger -> report`, the core's entity lists — resolves to a declared entity. If any name were misspelled or missing, the parser would reject the program before the IR is constructed.
|
||||
- **Syntactic sugar dissolved.** The `process { ... }` wrapper in leaf declarations is dissolved — the IR stores the action list directly. The semicolons and braces of the display format are the IR's canonical serialization, not the source syntax.
|
||||
|
||||
What is preserved: the complete program semantics. Every actor, state field, initialization value, handler, window, leaf action, pipeline ordering, and schedule parameter appears in the IR exactly as declared. Nothing is lost, nothing is added. The IR is a total, unambiguous description of the program.
|
||||
|
||||
## L1 Verification
|
||||
|
||||
L1 verification is a pass/fail gate — it produces no new IR. It reads the L1 IR and checks six structural properties. If any check fails, the pipeline stops and reports the specific violation.
|
||||
|
||||
The checks, mapped to the spec's four property categories:
|
||||
|
||||
| Property | Check | What it catches |
|
||||
|---|---|---|
|
||||
| **Safety** | Ref resolution | Every name in cores, pipelines, windows, and leaf actions resolves to a declared actor, leaf, or pipeline. Catches dangling references — a `forward` to a non-existent actor, a window naming a non-existent reader, a pipeline referencing an undeclared entity. |
|
||||
| **Safety** | Exclusive ownership | Each actor and leaf belongs to exactly one core. Prevents the same entity from being claimed by two different execution contexts. |
|
||||
| **Safety** | Window separation | Window readers must be leaves (not actors). Readers must be in the same core as the actor. A leaf that both reads a window on an actor AND forwards messages to that same actor is rejected — this would create a read-write hazard. |
|
||||
| **Consistency** | Pipeline well-formedness | Every pipeline has at least 2 stages. No stage appears twice within a pipeline (which would indicate a cycle). |
|
||||
| **Liveness** | Buffer conservation | Every leaf has at least one action (forward, read, or emit). A leaf with no actions would mean its input is never consumed. |
|
||||
| **Resource bound** | Finiteness | Every core has `steps > 0`. Cross-pipeline cycles are detected via topological sort — if the entity ordering across all pipelines contains a cycle, the program cannot make progress and is rejected. |
|
||||
|
||||
By the time verification passes, the L1 IR has been proven structurally sound: all references resolve, ownership is exclusive, windows are safe, pipelines are well-formed, buffers are consumed, and execution is bounded. The emit stage can trust its input completely.
|
||||
|
||||
## L0 IR
|
||||
|
||||
Emission transforms the verified L1 IR into L0 IR — the machine-level representation. This is the most important transformation in the pipeline. High-level concepts dissolve into explicit, low-level operations over named memory regions.
|
||||
|
||||
```
|
||||
=== Regions ===
|
||||
region ledger_state : 16 bytes, rw, state
|
||||
region ledger_purchase_queue : 272 bytes, rw, queue
|
||||
region step_counter : 8 bytes, rw, control
|
||||
region output : 48 bytes, rw, output
|
||||
=== Blocks ===
|
||||
entry:
|
||||
r0 = imm #0
|
||||
store.64 ledger_state[0], r0
|
||||
store.64 ledger_state[8], r0
|
||||
store.64 step_counter[0], r0
|
||||
store.64 output[0], r0
|
||||
jump -> loop_check
|
||||
loop_check:
|
||||
r1 = load.64 step_counter[0]
|
||||
r2 = imm #4
|
||||
r3 = cmp.lt r1, r2
|
||||
branch r3 -> step, exit
|
||||
step:
|
||||
r4 = imm #7
|
||||
queue_push ledger_purchase_queue, r4
|
||||
r5 = imm #3
|
||||
queue_push ledger_purchase_queue, r5
|
||||
r6 = queue_pop ledger_purchase_queue
|
||||
r7 = queue_pop ledger_purchase_queue
|
||||
r8 = load.64 ledger_state[0]
|
||||
r9 = add r8, r7
|
||||
store.64 ledger_state[0], r9
|
||||
r10 = load.64 ledger_state[8]
|
||||
r11 = mul r6, r7
|
||||
r12 = add r10, r11
|
||||
store.64 ledger_state[8], r12
|
||||
r13 = load.64 ledger_state[8]
|
||||
r14 = load.64 ledger_state[8]
|
||||
queue_push output, r14
|
||||
r15 = load.64 step_counter[0]
|
||||
r16 = add r15, #1
|
||||
store.64 step_counter[0], r16
|
||||
jump -> loop_check
|
||||
exit:
|
||||
terminate
|
||||
```
|
||||
|
||||
Here is what happened to each L1 concept:
|
||||
|
||||
**Actors became regions.** The actor `ledger` with state fields `count: u64 = 0` and `total: u64 = 0` became `region ledger_state : 16 bytes, rw, state` — two 8-byte fields at offsets 0 and 8. The actor's identity dissolved. What remains is a named, sized, access-controlled memory region. Loads and stores name this region explicitly: `store.64 ledger_state[0]` writes the count field, `store.64 ledger_state[8]` writes the total field.
|
||||
|
||||
**Messages became queues.** The `forward(ledger, Purchase(7, 3))` in the `buy` leaf became two `queue_push` operations — one for each argument (price=7, qty=3) — into `region ledger_purchase_queue : 272 bytes, rw, queue`. The actor's `on Purchase(price, qty)` handler became two `queue_pop` operations that retrieve those values, followed by arithmetic on the state region. The queue region is a ring buffer: 16 bytes for head and tail pointers, plus capacity for 16 messages × 2 arguments × 8 bytes = 256 bytes of data.
|
||||
|
||||
**The pipeline became a loop.** The `steps: 4` in the core schedule became `region step_counter : 8 bytes, rw, control`, a `loop_check` block with `cmp.lt` against immediate #4, and a conditional branch. Each iteration walks the pipeline stages in order (buy's forward → ledger's handler → report's read and emit), then increments the step counter and jumps back to `loop_check`.
|
||||
|
||||
**Window reads became loads.** The `report` leaf's `read(ledger.summary.total)` became `r13 = load.64 ledger_state[8]` — a direct load from the state region at the total field's offset. The window abstraction is gone; what remains is a memory access that the verifier already proved safe.
|
||||
|
||||
**Emit became a queue push.** The `emit(total)` became `queue_push output, r14` — pushing the loaded total value into `region output : 48 bytes, rw, output`. The output region is sized for exactly 4 steps: 16 bytes header + 4 × 8 bytes data = 48 bytes.
|
||||
|
||||
**Everything became explicit.** Every load, every store, every register assignment, every comparison, every branch is visible. There is no implicit state, no hidden control flow, no magic. The L0 IR is a total description of what the machine will do.
|
||||
|
||||
Walking through the blocks:
|
||||
|
||||
- **`entry`**: Loads immediate 0, stores it to both state fields (`ledger_state[0]` and `[8]`), the step counter, and the output head. Jumps to `loop_check`.
|
||||
- **`loop_check`**: Loads the step counter, loads the bound (4), compares. Branches to `step` if counter < 4, otherwise to `exit`.
|
||||
- **`step`**: Executes one complete pipeline iteration. Pushes price (7) and qty (3) to the queue, pops them back (simulating message delivery), loads count, adds qty, stores count. Loads total, multiplies price × qty, adds to total, stores total. Reads total through the window, pushes it to output. Increments step counter. Jumps back to `loop_check`.
|
||||
- **`exit`**: Terminates execution.
|
||||
|
||||
## L0 Verification
|
||||
|
||||
L0 verification checks the concrete IR after emission, before codegen. It collects all errors (unlike L1 verification which stops at the first). The checks:
|
||||
|
||||
| Property | Check | What it catches |
|
||||
|---|---|---|
|
||||
| **Safety** | Control flow targets | Every `branch` and `jump` names a block that exists. A dangling target would mean the program jumps into the void. |
|
||||
| **Safety** | Block reachability | Every block is reachable from the entry block (the first block) via BFS over control flow edges. Unreachable blocks are dead code that may contain invalid operations. |
|
||||
| **Safety** | Region declarations | Every `load` and `store` names a region that is declared in the regions list. An undeclared region reference would mean accessing memory that doesn't exist. |
|
||||
| **Safety** | Region bounds | Every memory access satisfies `offset + access_size ≤ region_size`. Out-of-bounds access would read or write past the region boundary. |
|
||||
| **Safety** | Access mode | Stores to read-only regions are rejected. The access mode is a compile-time invariant that codegen can rely on. |
|
||||
| **Resource bound** | Queue safety | `queue_push` and `queue_pop` only operate on regions with queue or output kind. Using queue operations on a state or control region would corrupt its layout. |
|
||||
| **Resource bound** | Memory capacity | Total memory is bounded — every region has a fixed size, and all sizes are known at compile time. The `total_memory()` utility sums all region sizes (in this program: 16 + 272 + 8 + 48 = 344 bytes). |
|
||||
|
||||
After L0 verification passes, the IR is proven safe for codegen: all control flow is valid, all memory accesses are in-bounds, all access modes are respected, and all queue operations target the correct region kinds.
|
||||
|
||||
## x86-64 Machine Code
|
||||
|
||||
Codegen translates the verified L0 IR into x86-64 machine code. The translation is mechanical: each L0 operation maps to a small, predictable cluster of x86 instructions.
|
||||
|
||||
### Raw hex dump
|
||||
|
||||
```
|
||||
53 55 41 54 41 55 41 56 41 57 4c 8b a7 00 00 00
|
||||
00 4c 8b af 08 00 00 00 4c 8b b7 10 00 00 00 4c
|
||||
8b bf 18 00 00 00 48 b8 00 00 00 00 00 00 00 00
|
||||
49 89 84 24 00 00 00 00 49 89 84 24 08 00 00 00
|
||||
49 89 86 00 00 00 00 49 89 87 00 00 00 00 e9 00
|
||||
00 00 00 49 8b 8e 00 00 00 00 48 ba 04 00 00 00
|
||||
00 00 00 00 48 39 d1 0f 9c c3 48 0f b6 db 48 85
|
||||
db 0f 85 05 00 00 00 e9 64 01 00 00 48 be 07 00
|
||||
00 00 00 00 00 00 49 8b bd 00 00 00 00 48 89 fd
|
||||
48 b9 03 00 00 00 00 00 00 00 48 c1 e5 03 48 81
|
||||
c5 10 00 00 00 4c 01 ed 48 89 75 00 48 81 c7 01
|
||||
00 00 00 49 89 bd 00 00 00 00 49 b8 03 00 00 00
|
||||
00 00 00 00 49 8b bd 00 00 00 00 48 89 fd 48 b9
|
||||
03 00 00 00 00 00 00 00 48 c1 e5 03 48 81 c5 10
|
||||
00 00 00 4c 01 ed 4c 89 45 00 48 81 c7 01 00 00
|
||||
00 49 89 bd 00 00 00 00 49 8b bd 08 00 00 00 48
|
||||
89 fd 48 c1 e5 03 48 81 c5 10 00 00 00 4c 01 ed
|
||||
4c 8b 4d 00 48 81 c7 01 00 00 00 49 89 bd 08 00
|
||||
00 00 49 8b bd 08 00 00 00 48 89 fd 48 c1 e5 03
|
||||
48 81 c5 10 00 00 00 4c 01 ed 4c 8b 55 00 48 81
|
||||
c7 01 00 00 00 49 89 bd 08 00 00 00 4d 8b 9c 24
|
||||
00 00 00 00 4c 89 d8 4c 01 d0 49 89 84 24 00 00
|
||||
00 00 49 8b 8c 24 08 00 00 00 4c 89 ca 49 0f af
|
||||
d2 48 89 cb 48 01 d3 49 89 9c 24 08 00 00 00 49
|
||||
8b b4 24 08 00 00 00 4d 8b 84 24 08 00 00 00 49
|
||||
8b bf 00 00 00 00 48 89 fd 48 b9 03 00 00 00 00
|
||||
00 00 00 48 c1 e5 03 48 81 c5 10 00 00 00 4c 01
|
||||
fd 4c 89 45 00 48 81 c7 01 00 00 00 49 89 bf 00
|
||||
00 00 00 4d 8b 8e 00 00 00 00 4d 89 ca 49 81 c2
|
||||
01 00 00 00 4d 89 96 00 00 00 00 e9 73 fe ff ff
|
||||
41 5f 41 5e 41 5d 41 5c 5d 5b c3
|
||||
```
|
||||
|
||||
491 bytes of x86-64 machine code.
|
||||
|
||||
### Annotated disassembly
|
||||
|
||||
The generated function follows the System V AMD64 calling convention. It receives a single argument in `rdi`: a pointer to an array of region base addresses. Region bases are loaded into dedicated registers at entry:
|
||||
|
||||
| Register | Region |
|
||||
|---|---|
|
||||
| R12 | `ledger_state` (16 bytes, state) |
|
||||
| R13 | `ledger_purchase_queue` (272 bytes, queue) |
|
||||
| R14 | `step_counter` (8 bytes, control) |
|
||||
| R15 | `output` (48 bytes, output) |
|
||||
|
||||
SSA registers are allocated from the remaining pool: RAX, RCX, RDX, RBX, RSI, R8–R11. RBP and RDI are used as scratch temporaries for queue address computation.
|
||||
|
||||
```asm
|
||||
; === prologue: save callee-saved registers ===
|
||||
0x00: push rbx ; save callee-saved
|
||||
0x01: push rbp
|
||||
0x02: push r12
|
||||
0x04: push r13
|
||||
0x06: push r14
|
||||
0x08: push r15
|
||||
|
||||
; === load region base pointers from rdi array ===
|
||||
0x0a: mov r12, [rdi+0x00] ; r12 = &ledger_state
|
||||
0x11: mov r13, [rdi+0x08] ; r13 = &ledger_purchase_queue
|
||||
0x18: mov r14, [rdi+0x10] ; r14 = &step_counter
|
||||
0x1f: mov r15, [rdi+0x18] ; r15 = &output
|
||||
|
||||
; === entry block: initialize regions ===
|
||||
; r0 = imm #0
|
||||
0x26: movabs rax, 0x0 ; rax = 0 (r0)
|
||||
|
||||
; store.64 ledger_state[0], r0 — count = 0
|
||||
0x30: mov [r12+0x00], rax
|
||||
|
||||
; store.64 ledger_state[8], r0 — total = 0
|
||||
0x38: mov [r12+0x08], rax
|
||||
|
||||
; store.64 step_counter[0], r0 — step = 0
|
||||
0x40: mov [r14+0x00], rax
|
||||
|
||||
; store.64 output[0], r0 — output head = 0
|
||||
0x47: mov [r15+0x00], rax
|
||||
|
||||
; jump -> loop_check
|
||||
0x4e: jmp 0x53 ; fall through to loop_check
|
||||
|
||||
; === loop_check block: compare step counter to bound ===
|
||||
; r1 = load.64 step_counter[0]
|
||||
0x53: mov rcx, [r14+0x00] ; rcx = step counter (r1)
|
||||
|
||||
; r2 = imm #4
|
||||
0x5a: movabs rdx, 0x4 ; rdx = 4 (r2)
|
||||
|
||||
; r3 = cmp.lt r1, r2
|
||||
0x64: cmp rcx, rdx ; compare step < 4
|
||||
0x67: setl bl ; bl = 1 if less
|
||||
0x6a: movzx rbx, bl ; rbx = zero-extended result (r3)
|
||||
|
||||
; branch r3 -> step, exit
|
||||
0x6e: test rbx, rbx ; test condition
|
||||
0x71: jne 0x7c ; if true → step block
|
||||
0x77: jmp 0x1e0 ; if false → exit block
|
||||
|
||||
; === step block: pipeline execution ===
|
||||
|
||||
; --- leaf buy: forward(ledger, Purchase(7, 3)) ---
|
||||
; r4 = imm #7
|
||||
0x7c: movabs rsi, 0x7 ; rsi = 7, the price (r4)
|
||||
|
||||
; queue_push ledger_purchase_queue, r4
|
||||
; load head, compute slot address, store value, increment head
|
||||
0x86: mov rdi, [r13+0x00] ; rdi = queue head
|
||||
0x8d: mov rbp, rdi ; rbp = head (working copy)
|
||||
0x90: movabs rcx, 0x3 ; rcx = 3 (modulo constant, unused here)
|
||||
0x9a: shl rbp, 0x3 ; rbp = head * 8
|
||||
0x9e: add rbp, 0x10 ; rbp += 16 (skip header)
|
||||
0xa5: add rbp, r13 ; rbp = &queue[head] absolute
|
||||
0xa8: mov [rbp+0x00], rsi ; queue[head] = 7 (price)
|
||||
0xac: add rdi, 0x1 ; head++
|
||||
0xb3: mov [r13+0x00], rdi ; store updated head
|
||||
|
||||
; r5 = imm #3
|
||||
0xba: movabs r8, 0x3 ; r8 = 3, the quantity (r5)
|
||||
|
||||
; queue_push ledger_purchase_queue, r5
|
||||
0xc4: mov rdi, [r13+0x00] ; rdi = queue head
|
||||
0xcb: mov rbp, rdi
|
||||
0xce: movabs rcx, 0x3
|
||||
0xd8: shl rbp, 0x3
|
||||
0xdc: add rbp, 0x10
|
||||
0xe3: add rbp, r13
|
||||
0xe6: mov [rbp+0x00], r8 ; queue[head] = 3 (qty)
|
||||
0xea: add rdi, 0x1
|
||||
0xf1: mov [r13+0x00], rdi ; store updated head
|
||||
|
||||
; --- actor ledger: queue_pop × 2, then handler body ---
|
||||
; r6 = queue_pop ledger_purchase_queue (price)
|
||||
0xf8: mov rdi, [r13+0x08] ; rdi = queue tail
|
||||
0xff: mov rbp, rdi
|
||||
0x102: shl rbp, 0x3
|
||||
0x106: add rbp, 0x10
|
||||
0x10d: add rbp, r13
|
||||
0x110: mov r9, [rbp+0x00] ; r9 = popped price value (r6)
|
||||
0x114: add rdi, 0x1 ; tail++
|
||||
0x11b: mov [r13+0x08], rdi ; store updated tail
|
||||
|
||||
; r7 = queue_pop ledger_purchase_queue (qty)
|
||||
0x122: mov rdi, [r13+0x08] ; rdi = queue tail
|
||||
0x129: mov rbp, rdi
|
||||
0x12c: shl rbp, 0x3
|
||||
0x130: add rbp, 0x10
|
||||
0x137: add rbp, r13
|
||||
0x13a: mov r10, [rbp+0x00] ; r10 = popped qty value (r7)
|
||||
0x13e: add rdi, 0x1
|
||||
0x145: mov [r13+0x08], rdi
|
||||
|
||||
; --- handler: count = count + qty ---
|
||||
; r8 = load.64 ledger_state[0] — load count
|
||||
0x14c: mov r11, [r12+0x00] ; r11 = count (r8)
|
||||
|
||||
; r9 = add r8, r7 — count + qty
|
||||
0x154: mov rax, r11 ; rax = count
|
||||
0x157: add rax, r10 ; rax = count + qty (r9)
|
||||
|
||||
; store.64 ledger_state[0], r9 — store updated count
|
||||
0x15a: mov [r12+0x00], rax
|
||||
|
||||
; --- handler: total = total + (price * qty) ---
|
||||
; r10 = load.64 ledger_state[8] — load total
|
||||
0x162: mov rcx, [r12+0x08] ; rcx = total (r10)
|
||||
|
||||
; r11 = mul r6, r7 — price * qty
|
||||
0x16a: mov rdx, r9 ; rdx = price
|
||||
0x16d: imul rdx, r10 ; rdx = price * qty (r11)
|
||||
|
||||
; r12 = add r10, r11 — total + (price * qty)
|
||||
0x171: mov rbx, rcx ; rbx = total
|
||||
0x174: add rbx, rdx ; rbx = total + price*qty (r12)
|
||||
|
||||
; store.64 ledger_state[8], r12 — store updated total
|
||||
0x177: mov [r12+0x08], rbx
|
||||
|
||||
; --- leaf report: read + emit ---
|
||||
; r13 = load.64 ledger_state[8] — read total through window
|
||||
0x17f: mov rsi, [r12+0x08] ; rsi = total (r13)
|
||||
|
||||
; r14 = load.64 ledger_state[8] — emit expression: load total
|
||||
0x187: mov r8, [r12+0x08] ; r8 = total (r14)
|
||||
|
||||
; queue_push output, r14 — emit(total)
|
||||
0x18f: mov rdi, [r15+0x00] ; rdi = output head
|
||||
0x196: mov rbp, rdi
|
||||
0x199: movabs rcx, 0x3
|
||||
0x1a3: shl rbp, 0x3
|
||||
0x1a7: add rbp, 0x10
|
||||
0x1ae: add rbp, r15 ; rbp = &output[head]
|
||||
0x1b1: mov [rbp+0x00], r8 ; output[head] = total
|
||||
0x1b5: add rdi, 0x1
|
||||
0x1bc: mov [r15+0x00], rdi ; head++
|
||||
|
||||
; --- step counter increment ---
|
||||
; r15 = load.64 step_counter[0]
|
||||
0x1c3: mov r9, [r14+0x00] ; r9 = step counter (r15)
|
||||
|
||||
; r16 = add r15, #1
|
||||
0x1ca: mov r10, r9
|
||||
0x1cd: add r10, 0x1 ; r10 = step + 1 (r16)
|
||||
|
||||
; store.64 step_counter[0], r16
|
||||
0x1d4: mov [r14+0x00], r10 ; store updated step counter
|
||||
|
||||
; jump -> loop_check
|
||||
0x1db: jmp 0x53 ; back to loop_check
|
||||
|
||||
; === exit block: terminate ===
|
||||
; restore callee-saved registers and return
|
||||
0x1e0: pop r15
|
||||
0x1e2: pop r14
|
||||
0x1e4: pop r13
|
||||
0x1e6: pop r12
|
||||
0x1e8: pop rbp
|
||||
0x1e9: pop rbx
|
||||
0x1ea: ret
|
||||
```
|
||||
|
||||
**Codegen strategy:**
|
||||
|
||||
- **Regions become register-indirect memory.** Each region's base address is loaded into a dedicated callee-saved register (R12–R15) at function entry. All loads and stores use these base registers with constant displacements: `mov [r12+0x08], rax` writes to `ledger_state` at offset 8 (the `total` field). Named regions preserve aliasing knowledge all the way to machine code — the codegen knows that `[r12+0x00]` and `[r14+0x00]` can never alias because they point to different regions.
|
||||
|
||||
- **Block structure maps to jump targets.** The L0 blocks (`entry`, `loop_check`, `step`, `exit`) become contiguous instruction sequences with `jmp`/`jne` instructions connecting them. Jump targets are resolved in a two-pass fixup: the first pass emits placeholder offsets, the second patches them once all block positions are known.
|
||||
|
||||
- **Queue operations translate to ring buffer indexing.** Each `queue_push` becomes: load head from `[base+0]`, compute slot address as `base + 16 + head*8`, store the value, increment head, store head back. `queue_pop` does the same with tail at `[base+8]`. The pattern is identical every time — five instructions for each queue operation.
|
||||
|
||||
- **Arithmetic is direct.** `add` → `add`, `mul` → `imul`. The move-then-operate pattern (`mov rax, r11; add rax, r10`) is the codegen's way of preserving SSA semantics in a register machine: the destination register is first loaded with the left operand, then the operation is applied with the right operand.
|
||||
|
||||
- **Comparisons use `setcc` + `movzx`.** The `cmp.lt` operation becomes `cmp rcx, rdx; setl bl; movzx rbx, bl` — compare, set a byte flag, zero-extend to 64 bits. The result feeds into `test rbx, rbx; jne` for the conditional branch.
|
||||
|
||||
## Execution
|
||||
|
||||
Running the program produces:
|
||||
|
||||
```
|
||||
Execution complete.
|
||||
step_counter[0] = 4
|
||||
output[0] = 4
|
||||
ledger_state[0] = 12
|
||||
ledger_purchase_queue[0] = 8
|
||||
output values: [21, 42, 63, 84]
|
||||
```
|
||||
|
||||
Interpreting the results:
|
||||
|
||||
- **`ledger_state[0] = 12`**: The `count` field. 4 steps × 3 units per step = 12. Correct.
|
||||
- **`step_counter[0] = 4`**: The loop ran exactly 4 iterations. Correct.
|
||||
- **`ledger_purchase_queue[0] = 8`**: The queue head advanced 8 positions (2 pushes per step × 4 steps). Correct.
|
||||
- **`output[0] = 4`**: The output head — 4 values were emitted. Correct.
|
||||
- **`output values: [21, 42, 63, 84]`**: The running total after each step:
|
||||
- Step 1: 0 + (7 × 3) = 21
|
||||
- Step 2: 21 + 21 = 42
|
||||
- Step 3: 42 + 21 = 63
|
||||
- Step 4: 63 + 21 = 84
|
||||
|
||||
Every value matches the program's intent. The total field (at `ledger_state[8]`, not shown in the summary line but readable from the region) holds 84. The loop from source intent to machine execution is closed.
|
||||
|
||||
## Closing
|
||||
|
||||
This walkthrough traced a single program through six transformations: parse, L1 verify, emit, L0 verify, codegen, execute. At each stage, the representation was shown in full — no excerpts, no elisions.
|
||||
|
||||
Three properties of the pipeline emerge from this trace. First, every representation is total and inspectable. The L1 IR is a complete, unambiguous description of the program. The L0 IR is a complete, explicit description of the execution. The machine code is a complete, executable binary. Nothing is hidden at any layer. Second, verification gates between representations mean each stage can trust its input. The emitter knows all references resolve because L1 verification proved it. The codegen knows all memory accesses are in-bounds because L0 verification proved it. Trust is replaced by proof.
|
||||
|
||||
Third, the transformations are mechanical and traceable. Every L0 instruction maps back to an L1 concept. Every x86 instruction maps back to an L0 operation. No stage introduces decisions the previous stage didn't authorize. The machine code is a direct consequence of the source program, with every intermediate step visible and verifiable.
|
||||
|
|
@ -9,3 +9,4 @@ pub mod pipeline;
|
|||
pub mod interpret_l1;
|
||||
pub mod translate_validate;
|
||||
pub mod repl;
|
||||
pub mod runtime;
|
||||
|
|
|
|||
24
src/main.rs
24
src/main.rs
|
|
@ -5,6 +5,7 @@ fn main() {
|
|||
if args.len() < 2 {
|
||||
eprintln!("Usage: l0-cpu-runtime <file.l1> [--dump-ir]");
|
||||
eprintln!(" l0-cpu-runtime verify <file.l1>");
|
||||
eprintln!(" l0-cpu-runtime run-verified <file.l1>");
|
||||
eprintln!(" l0-cpu-runtime repl");
|
||||
std::process::exit(1);
|
||||
}
|
||||
|
|
@ -38,6 +39,29 @@ fn main() {
|
|||
return;
|
||||
}
|
||||
|
||||
// Handle "run-verified" subcommand
|
||||
if args[1] == "run-verified" {
|
||||
if args.len() < 3 {
|
||||
eprintln!("Usage: l0-cpu-runtime run-verified <file.l1>");
|
||||
std::process::exit(1);
|
||||
}
|
||||
let path = &args[2];
|
||||
let source = std::fs::read_to_string(path).unwrap_or_else(|e| {
|
||||
eprintln!("Error reading '{}': {}", path, e);
|
||||
std::process::exit(1);
|
||||
});
|
||||
match pipeline::run_verified(&source) {
|
||||
Ok(report) => {
|
||||
print!("{}", report);
|
||||
}
|
||||
Err(e) => {
|
||||
eprintln!("Verified execution failed: {}", e);
|
||||
std::process::exit(1);
|
||||
}
|
||||
}
|
||||
return;
|
||||
}
|
||||
|
||||
let path = &args[1];
|
||||
let source = std::fs::read_to_string(path).unwrap_or_else(|e| {
|
||||
eprintln!("Error reading '{}': {}", path, e);
|
||||
|
|
|
|||
507
src/pipeline.rs
507
src/pipeline.rs
|
|
@ -3,9 +3,11 @@ use crate::emit::{self, EmitError};
|
|||
use crate::l0_ir::L0Program;
|
||||
use crate::l1_ir::L1Program;
|
||||
use crate::parser::{self, ParseError};
|
||||
use crate::runtime::{InvariantKind, InvariantResult, RuntimeTrace, check_output_determinism, RuntimeEngine};
|
||||
use crate::translate_validate::{self, VerificationReport};
|
||||
use crate::verify_l0;
|
||||
use crate::verify_l1::{self, VerifyError};
|
||||
use std::collections::HashMap;
|
||||
use std::fmt;
|
||||
|
||||
/// Errors from any stage of the pipeline.
|
||||
|
|
@ -17,6 +19,7 @@ pub enum PipelineError {
|
|||
VerifyL0(Vec<verify_l0::L0VerifyError>),
|
||||
Codegen(CodegenError),
|
||||
TranslationValidation(String),
|
||||
Runtime(String),
|
||||
}
|
||||
|
||||
impl fmt::Display for PipelineError {
|
||||
|
|
@ -34,6 +37,7 @@ impl fmt::Display for PipelineError {
|
|||
}
|
||||
PipelineError::Codegen(e) => write!(f, "codegen: {}", e),
|
||||
PipelineError::TranslationValidation(msg) => write!(f, "translation validation: {}", msg),
|
||||
PipelineError::Runtime(msg) => write!(f, "runtime: {}", msg),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -131,6 +135,193 @@ pub fn verify_translation(source: &str) -> Result<VerificationReport, PipelineEr
|
|||
Ok(report)
|
||||
}
|
||||
|
||||
/// Per-step summary of invariant check results.
|
||||
#[derive(Debug, Clone)]
|
||||
pub struct StepInvariantSummary {
|
||||
pub step: u64,
|
||||
pub checks: Vec<(InvariantKind, InvariantResult)>,
|
||||
}
|
||||
|
||||
/// Comprehensive report from the verified execution pipeline.
|
||||
#[derive(Debug)]
|
||||
pub struct VerifiedExecutionReport {
|
||||
/// Full runtime execution trace (phase transitions, messages, snapshots, outputs).
|
||||
pub trace: RuntimeTrace,
|
||||
/// Invariant check results grouped by step.
|
||||
pub step_invariants: Vec<StepInvariantSummary>,
|
||||
/// Final actor states as (name, fields) pairs.
|
||||
pub final_states: Vec<(String, Vec<(String, u64)>)>,
|
||||
/// Output values from the program.
|
||||
pub outputs: Vec<u64>,
|
||||
/// Translation validation report.
|
||||
pub verification_report: VerificationReport,
|
||||
/// Human-readable summary line.
|
||||
pub summary: String,
|
||||
}
|
||||
|
||||
impl fmt::Display for VerifiedExecutionReport {
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
writeln!(f, "=== Verified Execution Report ===")?;
|
||||
writeln!(f)?;
|
||||
|
||||
// Translation validation summary
|
||||
writeln!(f, "-- Translation Validation --")?;
|
||||
for result in &self.verification_report.results {
|
||||
let status = if result.passed { "PASS" } else { "FAIL" };
|
||||
writeln!(f, " [{}] {}", status, result.tool)?;
|
||||
}
|
||||
writeln!(f)?;
|
||||
|
||||
// Runtime invariants summary
|
||||
writeln!(f, "-- Runtime Invariants --")?;
|
||||
let total_checks: usize = self.step_invariants.iter()
|
||||
.map(|s| s.checks.len())
|
||||
.sum();
|
||||
let total_passed: usize = self.step_invariants.iter()
|
||||
.flat_map(|s| &s.checks)
|
||||
.filter(|(_, r)| *r == InvariantResult::Pass)
|
||||
.count();
|
||||
writeln!(f, " {} invariant checks across {} steps: {} passed, {} failed",
|
||||
total_checks, self.step_invariants.len(), total_passed, total_checks - total_passed)?;
|
||||
|
||||
// Per-kind summary
|
||||
let mut kind_counts: HashMap<InvariantKind, (usize, usize)> = HashMap::new();
|
||||
for step in &self.step_invariants {
|
||||
for (kind, result) in &step.checks {
|
||||
let entry = kind_counts.entry(*kind).or_insert((0, 0));
|
||||
entry.0 += 1;
|
||||
if *result == InvariantResult::Pass {
|
||||
entry.1 += 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
for kind in &[
|
||||
InvariantKind::Termination,
|
||||
InvariantKind::ActorSerialization,
|
||||
InvariantKind::MessageIntegrity,
|
||||
InvariantKind::StateIsolation,
|
||||
InvariantKind::WindowConsistency,
|
||||
InvariantKind::OutputDeterminism,
|
||||
] {
|
||||
if let Some((total, passed)) = kind_counts.get(kind) {
|
||||
let status = if total == passed { "PASS" } else { "FAIL" };
|
||||
writeln!(f, " [{}] {} ({}/{})", status, kind, passed, total)?;
|
||||
}
|
||||
}
|
||||
writeln!(f)?;
|
||||
|
||||
// Final states
|
||||
writeln!(f, "-- Final States --")?;
|
||||
for (name, fields) in &self.final_states {
|
||||
let flds: Vec<String> = fields.iter().map(|(n, v)| format!("{}={}", n, v)).collect();
|
||||
writeln!(f, " {} {{ {} }}", name, flds.join(", "))?;
|
||||
}
|
||||
|
||||
// Outputs
|
||||
if !self.outputs.is_empty() {
|
||||
writeln!(f, " outputs: {:?}", self.outputs)?;
|
||||
}
|
||||
writeln!(f)?;
|
||||
|
||||
writeln!(f, "-- Summary --")?;
|
||||
writeln!(f, " {}", self.summary)?;
|
||||
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
|
||||
/// Run the full verified execution pipeline: parse → L1 verify → emit → L0 verify
|
||||
/// → translation validation → runtime execution with all invariants → report.
|
||||
pub fn run_verified(source: &str) -> Result<VerifiedExecutionReport, PipelineError> {
|
||||
// Parse
|
||||
let l1 = parser::parse(source).map_err(PipelineError::Parse)?;
|
||||
|
||||
// Verify L1
|
||||
verify_l1::verify(&l1).map_err(PipelineError::VerifyL1)?;
|
||||
|
||||
// Emit L0 IR
|
||||
let l0 = emit::emit(&l1).map_err(PipelineError::Emit)?;
|
||||
|
||||
// Verify L0
|
||||
verify_l0::verify(&l0).map_err(PipelineError::VerifyL0)?;
|
||||
|
||||
// Translation validation
|
||||
let verification_report = translate_validate::validate(&l1, &l0);
|
||||
if !verification_report.all_passed() {
|
||||
return Err(PipelineError::TranslationValidation(format!("{}", verification_report)));
|
||||
}
|
||||
|
||||
// Runtime execution with invariants
|
||||
let mut engine = RuntimeEngine::new(&l1);
|
||||
let trace = engine.run_with_invariants(true)
|
||||
.map_err(|e| PipelineError::Runtime(e.message))?;
|
||||
|
||||
// Output determinism: run a second time and compare
|
||||
let mut engine2 = RuntimeEngine::new(&l1);
|
||||
let trace2 = engine2.run_with_invariants(false)
|
||||
.map_err(|e| PipelineError::Runtime(e.message))?;
|
||||
let determinism_result = check_output_determinism(&trace, &trace2);
|
||||
|
||||
// Build step invariant summaries
|
||||
let mut step_invariants: Vec<StepInvariantSummary> = Vec::new();
|
||||
for check in &trace.invariant_checks {
|
||||
let step_summary = step_invariants.iter_mut()
|
||||
.find(|s| s.step == check.step);
|
||||
match step_summary {
|
||||
Some(s) => s.checks.push((check.kind, check.result.clone())),
|
||||
None => step_invariants.push(StepInvariantSummary {
|
||||
step: check.step,
|
||||
checks: vec![(check.kind, check.result.clone())],
|
||||
}),
|
||||
}
|
||||
}
|
||||
|
||||
// Add output determinism to the last step's checks
|
||||
if let Some(last) = step_invariants.last_mut() {
|
||||
last.checks.push((InvariantKind::OutputDeterminism, determinism_result.clone()));
|
||||
}
|
||||
|
||||
// Final states
|
||||
let final_states: Vec<(String, Vec<(String, u64)>)> = trace.final_actor_states.iter()
|
||||
.map(|snap| (snap.actor_name.clone(), snap.fields.clone()))
|
||||
.collect();
|
||||
|
||||
let outputs = trace.all_outputs.clone();
|
||||
|
||||
// Build summary
|
||||
let total_checks: usize = step_invariants.iter().map(|s| s.checks.len()).sum();
|
||||
let all_invariants_passed = step_invariants.iter()
|
||||
.flat_map(|s| &s.checks)
|
||||
.all(|(_, r)| *r == InvariantResult::Pass);
|
||||
let all_translation_passed = verification_report.all_passed();
|
||||
|
||||
let summary = if all_invariants_passed && all_translation_passed {
|
||||
format!(
|
||||
"all {} invariant checks passed across {} steps; translation validation passed",
|
||||
total_checks, trace.steps.len()
|
||||
)
|
||||
} else {
|
||||
let failed: Vec<String> = step_invariants.iter()
|
||||
.flat_map(|s| &s.checks)
|
||||
.filter(|(_, r)| *r != InvariantResult::Pass)
|
||||
.map(|(k, r)| match r {
|
||||
InvariantResult::Fail(msg) => format!("{}: {}", k, msg),
|
||||
InvariantResult::Pass => unreachable!(),
|
||||
})
|
||||
.collect();
|
||||
format!("FAILURES: {}", failed.join("; "))
|
||||
};
|
||||
|
||||
Ok(VerifiedExecutionReport {
|
||||
trace,
|
||||
step_invariants,
|
||||
final_states,
|
||||
outputs,
|
||||
verification_report,
|
||||
summary,
|
||||
})
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
mod tests {
|
||||
use super::*;
|
||||
|
|
@ -304,4 +495,320 @@ mod tests {
|
|||
let result = verify_translation("invalid garbage");
|
||||
assert!(result.is_err());
|
||||
}
|
||||
|
||||
// ── Stage 4: Verified Execution Pipeline Tests ──────────────
|
||||
|
||||
#[test]
|
||||
fn run_verified_counter_all_invariants_pass() {
|
||||
let source = include_str!("../examples/counter.l1");
|
||||
let report = run_verified(source).expect("run_verified should succeed for counter");
|
||||
|
||||
// All six invariant kinds should be present
|
||||
let all_kinds: std::collections::HashSet<_> = report.step_invariants.iter()
|
||||
.flat_map(|s| s.checks.iter().map(|(k, _)| *k))
|
||||
.collect();
|
||||
assert!(all_kinds.contains(&crate::runtime::InvariantKind::Termination));
|
||||
assert!(all_kinds.contains(&crate::runtime::InvariantKind::ActorSerialization));
|
||||
assert!(all_kinds.contains(&crate::runtime::InvariantKind::MessageIntegrity));
|
||||
assert!(all_kinds.contains(&crate::runtime::InvariantKind::StateIsolation));
|
||||
assert!(all_kinds.contains(&crate::runtime::InvariantKind::WindowConsistency));
|
||||
assert!(all_kinds.contains(&crate::runtime::InvariantKind::OutputDeterminism));
|
||||
|
||||
// All should pass
|
||||
let all_pass = report.step_invariants.iter()
|
||||
.flat_map(|s| &s.checks)
|
||||
.all(|(_, r)| *r == crate::runtime::InvariantResult::Pass);
|
||||
assert!(all_pass, "all invariants should pass for counter");
|
||||
|
||||
// Final state should match
|
||||
assert_eq!(report.final_states.len(), 1);
|
||||
assert_eq!(report.final_states[0].0, "counter");
|
||||
assert_eq!(report.final_states[0].1, vec![("count".to_string(), 5)]);
|
||||
|
||||
// Summary should be positive
|
||||
assert!(report.summary.contains("passed"), "summary should indicate success: {}", report.summary);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn run_verified_window_all_invariants_pass() {
|
||||
let source = include_str!("../examples/window.l1");
|
||||
let report = run_verified(source).expect("run_verified should succeed for window");
|
||||
|
||||
let all_pass = report.step_invariants.iter()
|
||||
.flat_map(|s| &s.checks)
|
||||
.all(|(_, r)| *r == crate::runtime::InvariantResult::Pass);
|
||||
assert!(all_pass, "all invariants should pass for window");
|
||||
|
||||
assert_eq!(report.outputs, vec![10, 20, 30]);
|
||||
assert!(report.summary.contains("passed"));
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn run_verified_product_all_invariants_pass() {
|
||||
let source = include_str!("../examples/product.l1");
|
||||
let report = run_verified(source).expect("run_verified should succeed for product");
|
||||
|
||||
let all_pass = report.step_invariants.iter()
|
||||
.flat_map(|s| &s.checks)
|
||||
.all(|(_, r)| *r == crate::runtime::InvariantResult::Pass);
|
||||
assert!(all_pass, "all invariants should pass for product");
|
||||
|
||||
assert_eq!(report.outputs, vec![21, 42, 63, 84]);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn run_verified_report_final_states_match_jit() {
|
||||
let source = include_str!("../examples/counter.l1");
|
||||
let report = run_verified(source).expect("run_verified should succeed");
|
||||
let (jit_result, _) = run(source).expect("JIT should succeed");
|
||||
|
||||
let jit_count = jit_result.read_u64("counter_state", 0).unwrap();
|
||||
let verified_count = report.final_states[0].1.iter()
|
||||
.find(|(n, _)| n == "count").unwrap().1;
|
||||
assert_eq!(verified_count, jit_count, "verified and JIT final states must agree");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn run_verified_report_final_states_match_interpreter() {
|
||||
let source = include_str!("../examples/window.l1");
|
||||
let report = run_verified(source).expect("run_verified should succeed");
|
||||
let program = crate::parser::parse(source).unwrap();
|
||||
let interp_trace = crate::interpret_l1::interpret(&program).unwrap();
|
||||
|
||||
let verified_total = report.final_states[0].1.iter()
|
||||
.find(|(n, _)| n == "total").unwrap().1;
|
||||
let interp_total = interp_trace.final_actor_states[0].fields.iter()
|
||||
.find(|(n, _)| n == "total").unwrap().1;
|
||||
assert_eq!(verified_total, interp_total, "verified and interpreter final states must agree");
|
||||
assert_eq!(report.outputs, interp_trace.all_outputs, "verified and interpreter outputs must agree");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn run_verified_report_contains_translation_validation() {
|
||||
let source = include_str!("../examples/counter.l1");
|
||||
let report = run_verified(source).expect("run_verified should succeed");
|
||||
|
||||
assert_eq!(report.verification_report.results.len(), 3, "should have 3 translation validation tool results");
|
||||
assert!(report.verification_report.all_passed());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn run_verified_report_display_is_readable() {
|
||||
let source = include_str!("../examples/counter.l1");
|
||||
let report = run_verified(source).expect("run_verified should succeed");
|
||||
let text = format!("{}", report);
|
||||
|
||||
assert!(text.contains("Verified Execution Report"));
|
||||
assert!(text.contains("Translation Validation"));
|
||||
assert!(text.contains("Runtime Invariants"));
|
||||
assert!(text.contains("Final States"));
|
||||
assert!(text.contains("Summary"));
|
||||
assert!(text.contains("counter"));
|
||||
assert!(text.contains("count=5"));
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn run_verified_invalid_input() {
|
||||
let result = run_verified("invalid garbage");
|
||||
assert!(result.is_err());
|
||||
}
|
||||
|
||||
// ── Stage 5: Cross-Validation and Negative Testing ──────────
|
||||
|
||||
// --- Mutated L0 IR tests: corrupt emitted L0, verify translation validation catches it ---
|
||||
|
||||
fn emit_l0_for(source: &str) -> (crate::l1_ir::L1Program, crate::l0_ir::L0Program) {
|
||||
let l1 = crate::parser::parse(source).expect("parse");
|
||||
crate::verify_l1::verify(&l1).expect("verify L1");
|
||||
let l0 = crate::emit::emit(&l1).expect("emit");
|
||||
crate::verify_l0::verify(&l0).expect("verify L0");
|
||||
(l1, l0)
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn mutated_l0_counter_add_to_sub_caught() {
|
||||
let source = include_str!("../examples/counter.l1");
|
||||
let (l1, mut l0) = emit_l0_for(source);
|
||||
|
||||
// Corrupt: change Add to Sub in the step block
|
||||
let step = l0.blocks.iter_mut().find(|b| b.name == "step").unwrap();
|
||||
let mut mutated = false;
|
||||
for op in step.ops.iter_mut() {
|
||||
if let crate::l0_ir::Op::Arith { kind, .. } = op {
|
||||
if *kind == crate::l0_ir::ArithKind::Add {
|
||||
*kind = crate::l0_ir::ArithKind::Sub;
|
||||
mutated = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
assert!(mutated, "should have found an Add to corrupt");
|
||||
|
||||
let report = crate::translate_validate::validate(&l1, &l0);
|
||||
let trace_result = report.results.iter()
|
||||
.find(|r| r.tool == crate::translate_validate::ToolName::TraceEquivalence)
|
||||
.unwrap();
|
||||
assert!(!trace_result.passed, "trace checker should catch Add→Sub corruption");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn mutated_l0_window_add_to_sub_caught() {
|
||||
let source = include_str!("../examples/window.l1");
|
||||
let (l1, mut l0) = emit_l0_for(source);
|
||||
|
||||
let step = l0.blocks.iter_mut().find(|b| b.name == "step").unwrap();
|
||||
for op in step.ops.iter_mut() {
|
||||
if let crate::l0_ir::Op::Arith { kind, .. } = op {
|
||||
if *kind == crate::l0_ir::ArithKind::Add {
|
||||
*kind = crate::l0_ir::ArithKind::Sub;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
let report = crate::translate_validate::validate(&l1, &l0);
|
||||
assert!(!report.all_passed(), "should catch Add→Sub mutation in window example");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn mutated_l0_product_add_to_mul_caught() {
|
||||
let source = include_str!("../examples/product.l1");
|
||||
let (l1, mut l0) = emit_l0_for(source);
|
||||
|
||||
// Product uses Add for count and Mul for total — corrupt the Mul to Add
|
||||
let step = l0.blocks.iter_mut().find(|b| b.name == "step").unwrap();
|
||||
let mut mutated = false;
|
||||
for op in step.ops.iter_mut() {
|
||||
if let crate::l0_ir::Op::Arith { kind, .. } = op {
|
||||
if *kind == crate::l0_ir::ArithKind::Mul {
|
||||
*kind = crate::l0_ir::ArithKind::Add;
|
||||
mutated = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
assert!(mutated, "should have found a Mul to corrupt");
|
||||
|
||||
let report = crate::translate_validate::validate(&l1, &l0);
|
||||
assert!(!report.all_passed(), "should catch Mul→Add mutation in product example");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn mutated_l0_remove_queue_pop_caught() {
|
||||
let source = include_str!("../examples/counter.l1");
|
||||
let (l1, mut l0) = emit_l0_for(source);
|
||||
|
||||
// Remove all queue_pop ops from step block
|
||||
let step = l0.blocks.iter_mut().find(|b| b.name == "step").unwrap();
|
||||
let before = step.ops.len();
|
||||
step.ops.retain(|op| !matches!(op, crate::l0_ir::Op::QueuePop { .. }));
|
||||
assert!(step.ops.len() < before, "should have removed queue_pop ops");
|
||||
|
||||
let report = crate::translate_validate::validate(&l1, &l0);
|
||||
// Structural checker should catch missing queue_pop
|
||||
let structural = report.results.iter()
|
||||
.find(|r| r.tool == crate::translate_validate::ToolName::StructuralCorrespondence)
|
||||
.unwrap();
|
||||
assert!(!structural.passed, "structural checker should catch missing queue_pop");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn mutated_l0_wrong_loop_limit_caught() {
|
||||
let source = include_str!("../examples/counter.l1");
|
||||
let (l1, mut l0) = emit_l0_for(source);
|
||||
|
||||
// Change the loop limit from 5 to 3
|
||||
let loop_check = l0.blocks.iter_mut().find(|b| b.name == "loop_check").unwrap();
|
||||
for op in loop_check.ops.iter_mut() {
|
||||
if let crate::l0_ir::Op::LoadImm { value, .. } = op {
|
||||
if *value == 5 {
|
||||
*value = 3;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
let report = crate::translate_validate::validate(&l1, &l0);
|
||||
// Both trace checker (wrong final state) and BMC (wrong loop limit) should catch this
|
||||
assert!(!report.all_passed(), "should catch wrong loop limit");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn mutated_l0_remove_state_region_caught() {
|
||||
let source = include_str!("../examples/window.l1");
|
||||
let (l1, mut l0) = emit_l0_for(source);
|
||||
|
||||
l0.regions.retain(|r| r.name != "accumulator_state");
|
||||
|
||||
let report = crate::translate_validate::validate(&l1, &l0);
|
||||
let structural = report.results.iter()
|
||||
.find(|r| r.tool == crate::translate_validate::ToolName::StructuralCorrespondence)
|
||||
.unwrap();
|
||||
assert!(!structural.passed, "structural checker should catch missing state region");
|
||||
}
|
||||
|
||||
// --- Round-trip agreement: three-way cross-validation for all examples ---
|
||||
|
||||
fn three_way_agreement(source: &str, actor_name: &str, region_name: &str) {
|
||||
// 1. JIT pipeline
|
||||
let (jit_result, _) = run(source).expect("JIT pipeline should succeed");
|
||||
|
||||
// 2. Verified runtime
|
||||
let report = run_verified(source).expect("verified pipeline should succeed");
|
||||
|
||||
// 3. L1 interpreter
|
||||
let program = crate::parser::parse(source).unwrap();
|
||||
let interp_trace = crate::interpret_l1::interpret(&program).unwrap();
|
||||
|
||||
// Compare final actor states
|
||||
let verified_fields = &report.final_states.iter()
|
||||
.find(|(n, _)| n == actor_name).unwrap().1;
|
||||
let interp_fields = &interp_trace.final_actor_states.iter()
|
||||
.find(|s| s.actor_name == actor_name).unwrap().fields;
|
||||
|
||||
// Verified == Interpreter
|
||||
assert_eq!(verified_fields, interp_fields,
|
||||
"verified runtime and interpreter must agree on {} final state", actor_name);
|
||||
|
||||
// Verified == JIT (compare each field)
|
||||
let mut jit_offset = 0usize;
|
||||
for (name, verified_val) in verified_fields {
|
||||
let jit_val = jit_result.read_u64(region_name, jit_offset)
|
||||
.unwrap_or_else(|| panic!("JIT should have field {} at offset {}", name, jit_offset));
|
||||
assert_eq!(*verified_val, jit_val,
|
||||
"verified runtime and JIT must agree on {}.{}", actor_name, name);
|
||||
jit_offset += 8;
|
||||
}
|
||||
|
||||
// Compare outputs
|
||||
assert_eq!(report.outputs, interp_trace.all_outputs,
|
||||
"verified and interpreter outputs must agree");
|
||||
let jit_outputs = jit_result.read_output_values();
|
||||
assert_eq!(report.outputs, jit_outputs,
|
||||
"verified and JIT outputs must agree");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn round_trip_counter_three_way_agreement() {
|
||||
three_way_agreement(
|
||||
include_str!("../examples/counter.l1"),
|
||||
"counter", "counter_state",
|
||||
);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn round_trip_window_three_way_agreement() {
|
||||
three_way_agreement(
|
||||
include_str!("../examples/window.l1"),
|
||||
"accumulator", "accumulator_state",
|
||||
);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn round_trip_product_three_way_agreement() {
|
||||
three_way_agreement(
|
||||
include_str!("../examples/product.l1"),
|
||||
"ledger", "ledger_state",
|
||||
);
|
||||
}
|
||||
}
|
||||
|
|
|
|||
15
src/repl.rs
15
src/repl.rs
|
|
@ -707,6 +707,20 @@ pub fn execute_command<W: Write>(
|
|||
}
|
||||
}
|
||||
}
|
||||
"run-verified" => {
|
||||
if state.source.is_empty() {
|
||||
writeln!(out, "No program loaded. Use :load <file> or type declarations.").ok();
|
||||
} else {
|
||||
match pipeline::run_verified(&state.source) {
|
||||
Ok(report) => {
|
||||
write!(out, "{}", report).ok();
|
||||
}
|
||||
Err(e) => {
|
||||
write_colored(out, Color::Red, &format!("Verified execution failed: {}\n", e));
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
"help" => {
|
||||
print_help(out);
|
||||
}
|
||||
|
|
@ -800,6 +814,7 @@ fn print_help<W: Write>(out: &mut W) {
|
|||
(":ir", "Show current L1 IR with pipeline diagram"),
|
||||
(":l0", "Show emitted L0 IR (syntax-highlighted)"),
|
||||
(":verify", "Run formal verification pipeline"),
|
||||
(":run-verified", "Run with all invariant checks and produce verified report"),
|
||||
(":help", "Show this help and DSL reference"),
|
||||
(":examples", "List built-in examples"),
|
||||
(":examples <name>", "Load example with annotated walkthrough"),
|
||||
|
|
|
|||
Loading…
Reference in a new issue