Project: Synth - WebAssembly Component Synthesizer for Embedded Systems Version: 0.2.0 Last Updated: 2026-02-09 Status: Active Development
This section reflects what is actually implemented as of February 2026. The remaining sections describe the full architectural vision.
| Command | Description |
|---|---|
synth compile input.wat -o output.elf --cortex-m |
Single-function WASM to ARM Cortex-M ELF |
synth compile input.wat --all-exports --cortex-m -o out.elf |
Multi-function compilation |
synth compile --demo add --verify |
Compile + Z3 formal verification |
synth verify input.wat output.elf |
Standalone translation validation |
synth backends |
List available backends with capabilities |
synth compile --backend arm|w2c2 |
Backend selection (ARM functional, others stub) |
synth disasm output.elf |
Disassemble generated ELF |
synth-core
┌────────┴────────┐
│ Backend trait │
│ BackendRegistry │
└────────┬────────┘
│
┌───────────────┼───────────────┐
▼ ▼ ▼
synth-backend backend-awsm backend-wasker
(ARM, active) (stub) (stub)
All backends implement Backend::compile_function() and Backend::compile_module(). The ARM backend is fully functional; aWsm and wasker are stubs.
- Rule-level (ASIL D): Z3 SMT proves each synthesis rule (WASM op → ARM sequence) is semantically equivalent. 151/151 core ops have rules + unit tests; comparison ops (CMP+SetCond) verified via
ArmSequencepatterns. - Binary-level (ASIL B):
synth verifydisassembles generated ELF and validates against WASM source.
- 18 crates, ~45K lines of Rust
- 496+ tests (unit + Z3 verification + WAST integration + Renode emulation)
- 55+ Renode emulation tests pass (ARM Cortex-M4, via Bazel rules_renode)
- 151/151 WASM Core 1.0 ops have synthesis rules
┌─────────────┐
│ tests/wast/ │ 22 WAST files
└──────┬──────┘
│ synth-test generate
▼
┌─────────────┐
│ .robot files│ Robot Framework
└──────┬──────┘
│ bazel test (rules_renode)
▼
┌─────────────┐
│ Renode │ ARM Cortex-M4 emulation
└─────────────┘
Synth is a synthesizer, not just a compiler. The distinction is critical:
Traditional Compiler:
Source → Parse → Optimize → Generate → Machine Code
(deterministic transformations)
Synth Synthesizer:
WebAssembly Components → Analyze → Synthesize Optimal Implementation → Verify → Native Code
(explores space of equivalent programs, proves correctness)
- Synthesis-First: Explore optimization space, extract provably optimal code
- Component-Aware: Whole-program view of component compositions
- Hardware-Integrated: Leverage target-specific features (MPU/PMP, SIMD, XIP)
- Formally-Verified: Mechanically prove synthesis correctness
- Safety-Qualified: Generate certification artifacts for safety-critical use
VHDL Synthesis:
High-Level Description (VHDL)
→ Synthesis Tool (optimizes for area/power/timing)
→ Gate-Level Netlist
→ Place & Route
→ Physical Layout (FPGA/ASIC)
→ Formal Equivalence Checking
Synth (Software Synthesis):
High-Level Description (WebAssembly Components + WIT)
→ Synthesis Tool (optimizes for size/speed/power)
→ Intermediate Representation (optimized)
→ Target-Specific Lowering
→ Native Code (ARM/RISC-V)
→ Formal Translation Validation
┌─────────────────────────────────────────────────────────────┐
│ Development Environment │
│ │
│ ┌──────────┐ ┌──────────┐ ┌──────────┐ ┌──────────┐ │
│ │ Rust │ │ C │ │ C++ │ │ Other... │ │
│ │ Compiler │ │ Compiler │ │ Compiler │ │ Language │ │
│ └────┬─────┘ └────┬─────┘ └────┬─────┘ └────┬─────┘ │
│ │ │ │ │ │
│ └─────────────┴──────────────┴─────────────┘ │
│ │ │
│ WebAssembly │
│ Components │
│ ↓ │
│ ┌───────────────────────────────────────────────────────┐ │
│ │ │ │
│ │ SYNTH SYNTHESIZER │ │
│ │ │ │
│ │ Component Analysis → Optimization → Synthesis → │ │
│ │ Target Lowering → Verification │ │
│ │ │ │
│ └────────────────────┬───────────────────────────────────┘ │
│ │ │
│ Native Binary │
│ ↓ │
└─────────────────────────────────────────────────────────────┘
│
┌────────────────┴────────────────┐
│ │
┌──────▼────────┐ ┌─────────▼────────┐
│ ARM Cortex-M │ │ RISC-V │
│ Embedded │ │ Embedded │
│ Devices │ │ Devices │
└───────────────┘ └──────────────────┘
┌──────────────────────────────────────────────────────────────┐
│ SYNTH CORE │
├──────────────────────────────────────────────────────────────┤
│ │
│ ┌────────────────────────────────────────────────────────┐ │
│ │ FRONTEND: Component Model Parser & Validator │ │
│ │ - Parse WebAssembly Component binaries │ │
│ │ - Validate component structure │ │
│ │ - WIT interface processing │ │
│ │ - Build component dependency graph │ │
│ └───────────────────────┬────────────────────────────────┘ │
│ │ │
│ ↓ │
│ ┌────────────────────────────────────────────────────────┐ │
│ │ ANALYSIS: Whole-Program Analysis │ │
│ │ - Component composition analysis │ │
│ │ - Memory layout analysis (multi-memory) │ │
│ │ - Call graph construction │ │
│ │ - Data flow analysis │ │
│ │ - Hardware capability detection │ │
│ └───────────────────────┬────────────────────────────────┘ │
│ │ │
│ ↓ │
│ ┌────────────────────────────────────────────────────────┐ │
│ │ OPTIMIZATION: Synthesis Engine │ │
│ │ - E-graph construction (equality saturation) │ │
│ │ - ISLE-based rewrite rules │ │
│ │ - Cross-component optimization │ │
│ │ - Memory layout optimization │ │
│ │ - Bounds check optimization │ │
│ └───────────────────────┬────────────────────────────────┘ │
│ │ │
│ ↓ │
│ ┌────────────────────────────────────────────────────────┐ │
│ │ SYNTHESIS: Target-Specific Code Generation │ │
│ │ - ISLE instruction selection │ │
│ │ - Register allocation (regalloc2) │ │
│ │ - Hardware protection mapping (MPU/PMP) │ │
│ │ - XIP binary generation │ │
│ └───────────────────────┬────────────────────────────────┘ │
│ │ │
│ ↓ │
│ ┌────────────────────────────────────────────────────────┐ │
│ │ VERIFICATION: Formal Proof & Validation │ │
│ │ - Translation validation (SMT) │ │
│ │ - Memory safety proofs │ │
│ │ - CFI verification │ │
│ │ - Component isolation proofs │ │
│ └───────────────────────┬────────────────────────────────┘ │
│ │ │
│ ↓ │
│ ┌────────────────────────────────────────────────────────┐ │
│ │ BACKEND: Target Emission │ │
│ │ - ELF generation │ │
│ │ - Raw binary generation │ │
│ │ - Debug info (DWARF) │ │
│ │ - Certification artifacts │ │
│ └────────────────────────────────────────────────────────┘ │
│ │
└──────────────────────────────────────────────────────────────┘
Responsibilities:
- Parse WebAssembly Component Model binary format
- Validate component structure and types
- Process WIT interface definitions
- Build Abstract Syntax Tree (AST) representation
Architecture:
pub mod frontend {
pub struct ComponentParser {
wasm_parser: wasmparser::Parser,
wit_parser: wit_parser::Interface,
}
pub struct ComponentAST {
modules: Vec<CoreModule>,
components: Vec<Component>,
instances: Vec<ComponentInstance>,
interfaces: HashMap<String, WITInterface>,
}
pub struct ValidationContext {
type_checker: TypeChecker,
capability_checker: CapabilityChecker,
}
}Key Dependencies:
wasmparser(Bytecode Alliance)wit-parser(Bytecode Alliance)wasm-tools(validation)
Input: WebAssembly Component binaries (.wasm), WIT files (.wit) Output: Validated ComponentAST
Responsibilities:
- Construct component dependency graph
- Analyze memory usage across components
- Build call graph (with devirtualization opportunities)
- Perform data flow analysis
- Detect hardware capabilities
Architecture:
pub mod analysis {
pub struct DependencyGraph {
components: Vec<ComponentNode>,
edges: Vec<DependencyEdge>,
}
pub struct MemoryLayout {
linear_memories: Vec<MemoryRegion>,
mpu_regions: Vec<MPURegion>, // ARM
pmp_entries: Vec<PMPEntry>, // RISC-V
}
pub struct CallGraph {
functions: HashMap<FunctionID, FunctionNode>,
direct_calls: Vec<CallEdge>,
indirect_calls: Vec<IndirectCallSite>,
devirtualization_opportunities: Vec<DevirtualizationHint>,
}
pub struct HardwareCapabilities {
target: TargetArch,
has_mpu: bool,
mpu_regions: u8,
has_fpu: bool,
simd_support: SIMDLevel,
xip_capable: bool,
}
}Analyses Performed:
-
Component Dependency Analysis
- Shared-everything vs shared-nothing linking
- Identify optimization boundaries
-
Memory Layout Analysis
- Total memory requirements
- Multi-memory mapping to hardware regions
- Stack size estimation
-
Call Graph Construction
- Direct calls (statically known targets)
- Indirect calls (tables, dynamic dispatch)
- Devirtualization opportunities
-
Data Flow Analysis
- Constant propagation candidates
- Dead code identification
- Inlining candidates
Output: AnalysisResults containing all analysis data
Responsibilities:
- Construct e-graph of equivalent programs
- Apply synthesis/rewrite rules (ISLE-based)
- Explore optimization space via equality saturation
- Extract optimal program from e-graph
Architecture:
pub mod optimization {
use egg::{EGraph, Rewrite, Extractor};
pub struct SynthesisEngine {
egraph: EGraph<ComponentIR, ComponentAnalysis>,
rules: Vec<Rewrite<ComponentIR, ComponentAnalysis>>,
}
pub struct ComponentIR {
// E-graph representation of components
nodes: Vec<ENode>,
classes: Vec<EClass>,
}
pub struct ISLERules {
optimization_rules: Vec<ISLERule>,
target_lowering_rules: Vec<ISLERule>,
}
}Optimization Strategies:
1. Equality Saturation (E-Graphs):
Component IR → E-Graph Construction
→ Apply All Rewrite Rules
→ Saturation (fixed point)
→ Cost Model Extraction
→ Optimal Program
2. ISLE-Based Rewrites:
;; Example: Memory layout optimization
(rule (component_memory (mem_size s1) (mem_size s2))
(if (and (aligned s1) (aligned s2))
(merged_memory (+ s1 s2))))
;; Example: Devirtualization
(rule (indirect_call (known_target f) args)
(direct_call f args))
;; Example: Bounds check optimization
(rule (bounds_check addr (static_mem size))
(if (provably_in_bounds addr size)
(checked_access addr))) ;; Hardware check only
3. Cross-Component Optimization:
- Inline across component boundaries (shared-everything)
- Constant propagation through Canonical ABI
- Dead code elimination of unused exports
4. Memory Optimization:
- Merge compatible memories
- Optimize for MPU/PMP alignment
- Minimize total memory footprint
Output: Optimized ComponentIR ready for lowering
Responsibilities:
- Lower optimized IR to target-specific instructions (ISLE)
- Allocate registers (regalloc2)
- Map memories to hardware protection regions
- Generate XIP-capable binaries
Architecture:
pub mod synthesis {
pub struct TargetSynthesizer {
target: TargetDescriptor,
isle_lowering: ISLELowering,
reg_alloc: RegAllocator,
hw_mapper: HardwareMapper,
}
pub enum TargetDescriptor {
ARMCortexM {
variant: CortexMVariant,
has_fpu: bool,
has_mve: bool,
mpu_regions: u8,
},
RISCV {
variant: RISCVVariant,
extensions: Extensions,
pmp_entries: u8,
},
}
pub struct ISLELowering {
rules: Vec<LoweringRule>,
extractors: HashMap<String, Extractor>,
constructors: HashMap<String, Constructor>,
}
}Synthesis Steps:
1. ISLE Instruction Selection:
;; ARM Cortex-M specific lowering
(rule (lower (iadd x y))
(if (has_thumb2)
(add_reg (to_reg x) (to_reg y))
(add_reg_imm (to_reg x) (to_reg y))))
;; Memory access with MPU check
(rule (lower (load addr))
(if (has_mpu)
(load_with_mpu_check (map_to_region addr))
(load_with_software_check addr)))
;; RISC-V compressed instructions
(rule (lower (iconst n))
(if (and (has_rvc) (fits_in_ci n))
(c_li n) ;; 16-bit compressed
(li n))) ;; 32-bit standard
2. Register Allocation:
- Use regalloc2 from Cranelift
- Handle target-specific constraints (e.g., ARM R0-R3 for args)
- Minimize spills for small register files (Cortex-M: 16 regs)
3. Hardware Protection Mapping:
ARM Cortex-M MPU:
pub struct MPUMapper {
available_regions: u8, // 8 or 16 depending on variant
}
impl MPUMapper {
fn allocate_regions(&self, memories: &[Memory]) -> MPUConfig {
// Map each WebAssembly memory to MPU region
// Optimize for alignment (must be power-of-2 sized)
// Generate configuration code
}
}RISC-V PMP:
pub struct PMPMapper {
available_entries: u8, // Up to 16
}
impl PMPMapper {
fn allocate_entries(&self, memories: &[Memory]) -> PMPConfig {
// Map memories to PMP entries
// Configure for user-mode execution
// Generate CSR configuration code
}
}4. XIP Binary Generation:
- Position-independent code generation
- Minimal relocations
- Flash-friendly memory layout
- Indirect function calls via tables
Output: Target-specific machine code with hardware configuration
Responsibilities:
- Translation validation using SMT solvers
- Prove memory safety properties
- Verify control-flow integrity
- Check component isolation
Architecture:
pub mod verification {
pub struct TranslationValidator {
smt_solver: Z3Context,
wasm_semantics: WasmSemantics,
native_semantics: NativeSemantics,
}
pub struct MemorySafetyProver {
bounds_checker: BoundsChecker,
isolation_checker: IsolationChecker,
}
pub struct CFIVerifier {
call_checker: CallTargetChecker,
return_checker: ReturnChecker,
}
}Verification Approach:
1. Translation Validation (Per-Compilation):
For each synthesized function f:
1. Encode WebAssembly semantics as SMT formula φ_wasm
2. Encode native code semantics as SMT formula φ_native
3. Query SMT solver: ∀inputs. φ_wasm ≡ φ_native
4. If UNSAT: synthesis is correct
5. If SAT: counterexample found → bug in synthesis
2. Memory Safety Proof:
Theorem (Bounds Safety):
∀ memory access addr in synthesized code:
addr ∈ [memory.base, memory.base + memory.size)
Proof Strategy:
- Instrument all memory accesses
- Check bounds via SMT or runtime assertion
- If hardware MPU/PMP: prove configuration correct
3. Component Isolation Proof:
Theorem (Isolation):
∀ components C1, C2 with separate memories M1, M2:
Code in C1 cannot access M2 (except via Canonical ABI)
Proof Strategy:
- Static analysis of memory accesses
- Verify all accesses go through bounds checks
- Prove MPU/PMP regions don't overlap
4. Control-Flow Integrity Verification:
Theorem (CFI):
∀ indirect call sites:
target ∈ valid_function_table
type_signature_matches(target, expected_signature)
Proof Strategy:
- Verify type check inserted before every indirect call
- Check table bounds
- Prove function table immutable after initialization
Output: Verification results, proofs (for Coq), or SMT traces
Responsibilities:
- Generate final binary formats
- Emit debug information
- Create certification artifacts
Architecture:
pub mod backend {
pub struct BinaryEmitter {
format: BinaryFormat,
debug_info: DebugInfoGenerator,
}
pub enum BinaryFormat {
ELF { arch: Architecture },
RawBinary,
IntelHex,
}
pub struct DebugInfoGenerator {
dwarf_gen: DwarfGenerator,
source_map: SourceMap,
}
pub struct CertificationArtifactGenerator {
traceability: TraceabilityMatrix,
verification_evidence: VerificationEvidence,
}
}Generated Outputs:
-
Binary Files:
- ELF (with sections for text, data, bss)
- Raw binary (for direct flash programming)
- Intel HEX or Motorola S-Record
-
Debug Information:
- DWARF debug info
- Source-to-binary mapping
- Variable locations
-
Certification Artifacts:
- Requirements traceability matrix
- Verification evidence (SMT traces, proofs)
- Test coverage reports
- Static analysis results
Input: WebAssembly Components (.wasm) + WIT Interfaces (.wit) + Target Config
┌──────────────────────────────────────────────────────────┐
│ 1. FRONTEND: Parse & Validate │
│ - Parse component binaries │
│ - Validate structure and types │
│ - Build ComponentAST │
│ Output: Validated ComponentAST │
└────────────────────┬─────────────────────────────────────┘
│
↓
┌──────────────────────────────────────────────────────────┐
│ 2. ANALYSIS: Whole-Program Analysis │
│ - Build dependency graph │
│ - Analyze memory layout │
│ - Construct call graph │
│ - Detect hardware capabilities │
│ Output: AnalysisResults │
└────────────────────┬─────────────────────────────────────┘
│
↓
┌──────────────────────────────────────────────────────────┐
│ 3. OPTIMIZATION: E-Graph Synthesis │
│ - Construct e-graph from ComponentAST │
│ - Apply ISLE rewrite rules │
│ - Saturate (run until fixed point) │
│ - Extract optimal program via cost model │
│ Output: Optimized ComponentIR │
└────────────────────┬─────────────────────────────────────┘
│
↓
┌──────────────────────────────────────────────────────────┐
│ 4. SYNTHESIS: Target-Specific Lowering │
│ - ISLE instruction selection │
│ - Register allocation (regalloc2) │
│ - Map memories to MPU/PMP regions │
│ - Generate hardware config code │
│ Output: Target-specific machine code │
└────────────────────┬─────────────────────────────────────┘
│
↓
┌──────────────────────────────────────────────────────────┐
│ 5. VERIFICATION: Formal Validation │
│ - SMT-based translation validation │
│ - Memory safety proofs │
│ - CFI verification │
│ - Isolation proofs │
│ Output: Verification results + proofs │
└────────────────────┬─────────────────────────────────────┘
│
↓
┌──────────────────────────────────────────────────────────┐
│ 6. BACKEND: Binary Emission │
│ - Generate ELF/binary │
│ - Emit debug info (DWARF) │
│ - Create certification artifacts │
│ Output: Native binary + artifacts │
└──────────────────────────────────────────────────────────┘
Final Output:
- Native binary (ELF/raw)
- Debug information
- Verification proofs
- Certification artifacts
WebAssembly: (i32.load offset=4 align=2 (local.get $addr))
↓ FRONTEND: Parse
Load { offset: 4, align: 2, addr: Local(0) }
↓ ANALYSIS: Memory Layout Analysis
- Memory 0 mapped to MPU region 2 (0x20000000-0x20010000)
- Access pattern: sequential reads
- Alignment: 4-byte aligned
↓ OPTIMIZATION: E-Graph Synthesis
- Combine offset into addressing mode
- Recognize sequential pattern (potential for load-multiple)
- Bounds check optimization: hardware MPU covers this region
↓ SYNTHESIS: ARM Cortex-M Lowering (ISLE)
Rule: (load (+ base (const 4)))
→ ldr r0, [r1, #4] ;; Offset in instruction, no bounds check needed
Hardware config:
MPU Region 2: 0x20000000, 64KB, Read/Write, User accessible
↓ VERIFICATION: Translation Validation
SMT query:
wasm_memory[addr + 4] ≡ native_memory[mpu_region_2_base + addr + 4]
Result: UNSAT (semantics equivalent)
Memory safety proof:
addr + 4 < 0x10000 (within 64KB) → MPU allows access
Proven correct
↓ BACKEND: Code Emission
Generated ARM code:
ldr r0, [r1, #4] ; Load with offset
MPU config code:
MPU->RNR = 2;
MPU->RBAR = 0x20000000;
MPU->RASR = (SIZE_64KB | RW | USER);
Decision: Use egg library for equality saturation
Rationale:
- Solves phase-ordering problems
- Explores all equivalent programs simultaneously
- Provably optimal extraction
- Production-ready Rust implementation
Alternatives Considered:
- Traditional pass-based optimizer (rejected: phase-ordering issues)
- Custom rewrite system (rejected: reinventing wheel)
Consequences:
- Increased compilation time (acceptable for AOT)
- Requires learning e-graph concepts
- Better optimization results
Decision: Use ISLE DSL for instruction lowering and rewrites
Rationale:
- Declarative specification enables formal verification
- Proven in Cranelift production use
- Modular, testable rules
- VeriISLE provides SMT-based verification
Alternatives Considered:
- Hand-written Rust code (rejected: hard to verify, error-prone)
- LLVM backend (rejected: too heavyweight, hard to customize)
- Custom DSL (rejected: significant development cost)
Consequences:
- Need to learn ISLE language
- Dependency on Cranelift's ISLE compiler
- Clear verification path
Decision: Map WebAssembly memories to MPU/PMP regions
Rationale:
- Leverages existing hardware for sandboxing
- Reduces performance overhead vs software checks
- Enables formal verification of memory isolation
- Natural fit for multi-memory proposal
Alternatives Considered:
- Software-only bounds checks (rejected: performance overhead)
- Virtual memory guard pages (rejected: not available on Cortex-M)
- No bounds checking (rejected: loses WebAssembly guarantees)
Consequences:
- Requires careful region allocation
- Limited number of regions (8-16)
- Need fallback for targets without MPU/PMP
Decision: Support AOT compilation only, no JIT
Rationale:
- Embedded targets often prohibit dynamic code generation
- Deterministic performance critical for real-time
- Enables ahead-of-time formal verification
- Simpler architecture
Alternatives Considered:
- JIT compilation (rejected: security concerns, determinism issues)
- Hybrid AOT+JIT (rejected: added complexity)
Consequences:
- Longer build times acceptable
- All code known at synthesis time
- Easier verification
Decision: Target WebAssembly Component Model, not core modules
Rationale:
- Component Model provides structured composition
- Multi-memory support for isolation
- Canonical ABI for cross-language interop
- Future-proof for WASI evolution
Alternatives Considered:
- Core WebAssembly only (rejected: lacks composition features)
- Custom module system (rejected: not standards-based)
Consequences:
- Requires Component Model tooling (wasm-tools, etc.)
- Smaller initial ecosystem vs core Wasm
- Better long-term architecture
Decision: Implement Synth in Rust
Rationale:
- Memory safety without garbage collection
- Excellent WebAssembly tooling ecosystem (Bytecode Alliance)
- Strong type system for correctness
- Good performance
Alternatives Considered:
- C++ (rejected: memory safety concerns)
- OCaml (rejected: smaller embedded tooling ecosystem)
- Zig (rejected: less mature, smaller ecosystem)
Consequences:
- Learning curve for Rust
- Compile times can be long
- Excellent safety and correctness
WebAssembly Tooling:
wasmparser0.222 - Parse WASM binarieswast222.0 - WAST text format parsing (test infrastructure)wat1.222 - WAT to WASM binary conversionwasm-tools- Validation and component manipulationwit-parser,wit-component- Component Model support
Code Generation (custom — no LLVM/Cranelift dependency):
- Custom
ArmEncoder- ARM Thumb-2 machine code emission - Custom
InstructionSelector- WASM→ARM lowering via pattern matching - Custom
ElfBuilder- ELF32 binary generation - Custom
VectorTable,ResetHandler- Cortex-M startup code
Verification:
z30.12 /z3-sys0.8 - SMT solver for translation validation- Custom
arm_semantics.rs(~3000 lines) - ARM instruction SMT encoding
Build Systems:
- Cargo (primary:
cargo test --workspace) - Bazel 8.x (Renode integration tests:
bazel test //...) rules_renode(PulseEngine fork with macOS support)
Testing Infrastructure:
- 22 WAST files auto-generate Robot Framework tests
synth-testcrate: WAST parser → Robot generator → Renode execution- Bazel hermetic Renode (no system install needed)
CI/CD:
- GitHub Actions (
cargo test,cargo clippy, Z3 verification)
synth compile <INPUT.wat> -o <OUTPUT.elf> [OPTIONS]
--cortex-m Generate complete Cortex-M binary (vector table + startup)
--all-exports Compile all exported functions
--backend <NAME> Select backend (arm, w2c2, awsm, wasker)
--verify Run Z3 formal verification after compilation
--no-optimize Skip optimization passes
synth verify <INPUT.wat> <OUTPUT.elf>
Standalone translation validation via Z3 SMT
synth disasm <ELF>
Disassemble and display generated ARM code
synth backends
List available backends and their capabilities
synth parse <INPUT.wasm>
Parse and analyze WASM module structure
use synth::{Synthesizer, TargetConfig, SynthesisOptions};
let config = TargetConfig::cortex_m4f()
.with_mpu_regions(8)
.with_xip(true);
let options = SynthesisOptions::default()
.optimize_for_size()
.enable_verification();
let synthesizer = Synthesizer::new(config, options)?;
let binary = synthesizer.synthesize_from_file("app.wasm")?;
binary.write_elf("output.elf")?;
binary.emit_artifacts("artifacts/")?;Cargo Integration (Rust):
[build-dependencies]
synth = "0.1"
[package.metadata.synth]
target = "thumbv7em-none-eabihf"
opt-level = "z"
verify = trueCMake Integration (C/C++):
find_package(Synth REQUIRED)
add_wasm_component(my_app
SOURCES app.c
WIT_INTERFACE interface.wit
TARGET cortex-m4f
OPTIMIZE_FOR size
)
synth_synthesize(my_app
OUTPUT my_app.elf
VERIFY ON
)Expected Performance:
- Small components (<100KB): <1 second
- Medium components (100KB-1MB): 1-10 seconds
- Large components (>1MB): 10-60 seconds
- With full verification: 2-10x slower
Optimization Strategies:
- Parallel compilation of independent components
- Incremental compilation (cache analysis results)
- Lazy verification (only verify changed components)
Target Performance (vs hand-written native):
- ≥80% for compute-intensive code
- ≥85% for memory-intensive code
- ≥90% for control-flow-heavy code
Key Optimizations:
- Hardware-assisted bounds checking (near-zero overhead)
- Devirtualization (eliminate indirect call overhead)
- SIMD utilization (Helium on M55, RISC-V V extension)
- XIP (no load-time overhead)
Code Size:
- Target: <120% of equivalent native code
- XIP reduces RAM requirements significantly
Runtime Memory:
- No allocator required for synthesized code
- Predictable stack usage (static analysis)
- Minimal metadata overhead
Threat: Malicious WebAssembly components
Mitigation:
- Comprehensive validation before synthesis
- Bounds on resource usage (memory, stack)
- Reject invalid or malformed components
Threat: Bugs in synthesizer leading to unsafe code
Mitigation:
- Translation validation (SMT-based)
- Fuzzing with differential testing
- Formal verification of critical paths
- Continuous integration testing
Threat: Component escaping sandbox
Mitigation:
- Hardware-enforced memory isolation (MPU/PMP)
- Control-flow integrity verification
- Component isolation proofs
- Runtime trap handling
- Additional Targets: Xtensa (ESP32), ARMv8-A (Cortex-A)
- SIMD Optimization: Advanced auto-vectorization
- Profiling Integration: Profile-guided optimization
- Incremental Compilation: Faster rebuild times
- WebAssembly GC Support: Garbage collection proposal
- WASI Preview 3: Async/await support
- End-to-End Verification: Full mechanized proof in Coq
- Safety Certification: ISO 26262 / IEC 62304 qualified tool
- Multi-Core Support: Parallel component execution
- Dynamic Linking: Runtime component loading (with constraints)
- Custom Instructions: Target-specific ISA extensions
- Hardware Accelerators: Offload to DSPs, FPGAs
- ✓ Synthesis time <10s for typical component
- ✓ Generated code ≥80% native performance
- ✓ Code size <120% of native equivalent
- ✓ Verification time <60s for typical component
- ✓ Pass 100% of WebAssembly Component Model test suite
- ✓ Zero known correctness bugs in stable releases
- ✓ >90% code coverage in test suite
- ✓ Translation validation passes for all syntheses
- ✓ <10 steps to synthesize first component
- ✓ Clear error messages for all failures
- ✓ Comprehensive documentation with examples
- ✓ Integration with popular toolchains (Cargo, CMake)
Document Status: Draft v0.1 Next Steps: Review and refine, begin prototype implementation Approval Required: Technical Lead, Architecture Review Board