Coredistools wasm32#437
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Adds wasm32 as a supported target architecture for the coredistools
disassembler. This is the first step toward enabling SuperPMI asm-diffs
for collections produced by the LLVM/Wasm RyuJIT backend, which today
fall through to a host-arch decode and silently degrade to roughly
bitwise comparison of framed Wasm blobs.
Changes:
- coredistools.h: add Target_Wasm32 to TargetArch enum.
- coredistools.cpp: handle Target_Wasm32/Triple::wasm32 in setTarget()
host-detect and explicit-target switches; set a starter Wasm feature
string in init() covering the proposals the LLVM/Wasm JIT may emit
(simd128, sign-ext, nontrapping-fptoint, mutable-globals,
reference-types, bulk-memory, tail-call, exception-handling,
multivalue). Keep this in sync with the JIT's emitted feature set on
each LLVM bump.
- build-coredistools.{cmd,sh} and build-tblgen.{cmd,sh}: append
WebAssembly to the default LLVMTargetsToBuild. Per-arch restricted
matrix legs (linux-arm, linux-loongarch64, linux-riscv64, win-x86)
are left unchanged - wasm32 diffing is not a use case for those
hosts.
Follow-ups (not in this change):
- Frame-aware iteration: walking the per-funclet ULEB128 length prefix
and the per-body locals declaration before disassembling.
- Wasm-aware OffsetComparator on the SuperPMI side, driven by the
recorded relocation table.
- .wat-style dump output on diff.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The LLVM/Wasm RyuJIT backend writes its code buffer as a sequence of length-prefixed function/funclet bodies (ULEB128 body-length followed by the body bytes, where each body begins with the standard Wasm locals declaration). This shape doesn't fit the existing "flat instruction stream" assumption baked into nearDiff/dumpBlock, so Target_Wasm32 collections currently flow through asm-diffs as opaque bytes (or worse, get fed to the host-arch decoder). Add a Wasm-aware path that understands the framing: - Internal ULEB128 reader (readULEB128) plus parseWasmLocals/ formatWasmLocals helpers for the per-body header. - CorDisasm::dumpWasmFramedBlock walks each body, prints the locals header in (local i32 i32 ...) form, then disassembles the opcode stream using the existing LLVM WebAssembly MCInstPrinter (-> .wat- ish output). - CorAsmDiff::nearDiffWasmFramed walks both buffers in lockstep body by body, requires matching locals headers, and falls back to the OffsetComparator on differing integer immediates. The comparator is passed the opcode-byte offset measured from the start of the framed buffer so SuperPMI's recorded reloc tables can be looked up directly. - dumpDiffWasmFramed prints both sides with baseline/diff labels. New entry points NearDiffCodeBlocksFramed, DumpCodeBlockFramed and DumpDiffBlocksFramed are exported for callers that want to be explicit; the existing NearDiffCodeBlocks / DumpCodeBlock / DumpDiffBlocks entry points auto-route to the framed path when the configured target is Target_Wasm32 (the framing is intrinsic to the target, so this is safe). Bump nuspec version to 1.7.0 to reflect the added API surface. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Add Wasm32 support to coredistools.