[Go] Encode ABI0 in function symbol names - #77
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zhouguangyuan0718 merged 1 commit intoAug 13, 2026
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Use a reserved <ABI0> suffix as the sole ABI0 function identity across IR declarations, definitions, MC symbols, and GoObj references. Strip the suffix while writing GoObj and preserve unsuffixed ABIInternal function names.\n\nRemove goobj.symbol.name and MC ABI override state. Late morestack calls acquire the ABI0 suffix, while unsuffixed late call relocations such as write barriers resolve as ABIInternal.
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## Summary - use `go-nosplit` as the sole opt-out from the native Go stack check; split functions call `runtime.morestack*<ABI0>` with an ordinary target call - emit one function-level `EntryArgsStackMapID` record for every GoObj Go function, independent of split/nosplit behavior - serialize the entry map as map 0 and use the Machine-CFG-derived PCSP stream to restore map 0 on entry-stack-depth paths, without identifying `runtime.morestack*` in GoObj emission - serialize ordinary statepoints as additional live maps and let same-PC statepoints override a CFG map-0 transition - retain complete ABI register homes for morestack retries while omitting unused, potentially poison incoming pointer values from the entry GC bitmap - model `go-systemstack` with `g.stackguard1` and `runtime.morestackc` ## Stack position This is 2/3 in the runtime LLVM support stack. Depends on #77. Next/final layer: #76, X86 ABI0/ABIInternal boundary repair. #75 has been folded into this PR so the stack semantics and the entry-map contract can be reviewed as one coherent change. ## Testing - fresh Release build of `llc` for X86 and AArch64 - 12 `GoObjStackMapUtilsTest` unit tests - 38 Generic/X86/AArch64 GoObj codegen tests - dedicated object test covering map 0 -> ordinary map 1 -> CFG-derived map 0 on both targets
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## Summary - keep R14 and XMM15 reserved under both Go calling conventions and retain the shared Go preserved-register model - repair ABIInternal reserved state in a late X86 machine pass after register allocation, frame lowering, and scheduling - identify direct ABI0 callees solely through the `<ABI0>` symbol suffix; statepoints use their existing calling-convention operand - leave late special calls outside the ordinary ABI transition path: morestack resumes through `gogo`, and write-barrier thunks use their dedicated ABIInternal clobber contract - keep SP-relative Go locals while preserving ABI-specific fixed incoming argument homes - emit native-compatible symbol-free x86 TLS relocations for the R14 reload ## Design R14 and XMM15 are fixed reserved registers rather than ordinary caller-saved or callee-saved allocation resources. The transition repair therefore does not participate in SelectionDAG lowering and does not require a target pseudo or a distinct ABI0 register mask. The `x86-go-abi` pre-emit pass scans finalized MachineInstr calls. For an ordinary Go call, `<ABI0>` is the only ABI0 identity. It inserts `XORPS XMM15, XMM15` and a TLS reload of R14 before ABI0-to-ABIInternal calls or after ABIInternal-to-ABI0 calls. Calls inserted late without the ordinary Go call mask are intentionally ignored. This matches native Go behavior for split-stack morestack calls and write-barrier thunks. ## Stack position This is the X86 ABI-boundary layer on top of merged #73 and merged #77. #71 remains the temporary cross-repository integration and payload PR until this PR is merged. ## Testing - independent Release plus assertions build of `llc` and `FileCheck` - focused LLVM lit validation: 7 of 7 passed - verified normal calls, statepoints, stack-return statepoints, GoObj relocations, stack growth, PCSP CFG handling, and ABI symbol naming - verified pass timing: no repair at finalize-isel or immediately before `x86-go-abi`; repair appears only after the late pass - verified native-special behavior: no repair is inserted after morestack or write-barrier calls
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Use the LLVM symbol name as the sole ABI identity contract for Go functions:
<ABI0>suffix.<ABI0>and writes ABI0; unsuffixed Go function symbols write ABIInternal.goobj.symbol.namemetadata and MC ABI override state.runtime.morestack*calls use suffixed ABI0 names; unsuffixed late call relocations such as write barriers resolve as ABIInternal.The tests cover same-name ABI0/ABIInternal definitions, declarations referenced through function pointers, mismatch rejection, x86_64/AArch64 morestack lowering, write barriers, and raw MC call/data relocation defaults.
Validation: