[MeteorsLiu]

Verify every retained native signal symbol and exercise real handler delivery while preserving the existing Signal contract.

The implementation includes:

• Generate native signal records and APIs from macOS 14 and Bootlin glibc 2.24 for macOS arm64 and Linux amd64/arm64 using unmodified llcppg.
• Keep Signal returning the Sigaction installation status and NativeSignal returning C signal's previous handler; use generated records and union accessors without changing existing public function signatures.
• Remove private C implementation entry points and the private macOS wrapper source, and exclude Linux SysSiglist with explicit approval because current glibc provides no default sys_siglist export.
• Cover every retained C function with a symbol-address and native-prototype check, and check all public type layouts, constants, native globals and generated union accessors; recognize _xgo_union storage as a C union while retaining all size/alignment assertions.
• Exercise guarded sigaction output, signal-set operations, handler installation/restoration, real Raise delivery, Kill(self, 0), and the complete Linux non-notifying timer lifecycle. TimerCreate keeps its link check and uses an approved static signature/ABI check to avoid the dependency's reflection-wrapper limitation.

Executed LLGo v1.0.8 (c171abfa130108bc6451e01fcf15a8a3474eb0a7) GC and nogc tests pass on all three targets. Validation includes #45's root c files at 99ddac92c7335a53a1c996174e1753bcd72c5050 and #51's c/time files at 855f0c294499b32a0d3380d1d608592255155e89; merge #45, then #51, before this draft. Standalone build CI currently reports undefined: lltime.TimerT because #51 is not merged. The existing c/time full-signature reflection limitation remains documented and unchanged. This PR changes only c/signal and makes missing symbol coverage and native layout regressions visible.

[MeteorsLiu]

Merge order: #45 → #51 → #48 → #49 → #44 → #47 → #46 → #50 → #52.

This draft changes only c/signal. Its validation snapshot includes #45's root c files at 99ddac92c7335a53a1c996174e1753bcd72c5050 and #51's c/time at 855f0c294499b32a0d3380d1d608592255155e89. Linux signal bindings require the timer types from #51, so that prerequisite must merge first.

All retained native signal functions have link-address and native-prototype coverage; public types, constants, globals and generated union accessors also have complete source-inventory coverage. Executed tests pass on macOS arm64, Linux amd64 and Linux arm64 with GC and -tags=nogc, using LLGo v1.0.8 (c171abfa). Runtime tests include real signal delivery to the installed handler and the unchanged Linux timer lifecycle assertions.

Private C entry points and their private macOS wrapper are removed. Linux SysSiglist is excluded with explicit approval, while macOS keeps its native globals. Signal and NativeSignal retain their distinct status-return and previous-handler-return contracts. The approved static TimerCreate prototype test preserves its full link and lifecycle checks without modifying c/time or llcppg. The PR remains draft.

Standalone build CI currently stops at c/signal/libc_linux_amd64.go:655:81: undefined: lltime.TimerT, because #51 has not merged. The six passing signal runs include the documented prerequisite snapshots.

[fennoai]

Review — c/signal native types

Ran code-quality, performance, security, and documentation passes over the four generated files.

Verified correct — no action needed

• Struct layouts match the glibc amd64 ABI, confirmed with a size/offset probe: SiginfoT = 128 bytes (__SI_MAX_SIZE) with _sifields at offset 16, Sigval = 8 bytes, SigsetT = 128 bytes ([16]c.Ulong). Darwin SigsetT resolves to a 4-byte uint32, matching __darwin_sigset_t.
• Every XGof_ref_* accessor casts strictly within its backing union — no out-of-bounds reads — and they are zero-cost unsafe.Pointer reinterpretations (no copies/allocations).
• Package builds for linux/amd64 and darwin/arm64; all files are gofmt-clean.

Findings (non-blocking)
These are llcppg-generated files, so fixes most likely belong in the generator/config rather than hand edits.

• Platform-coverage gap on the published type surface — see inline on llcppg.pub.
• [???] doc placeholder — see inline on types_darwin_arm64.go.

Minor nits

• _llcppg_anon_34 (_sigsys, libc_linux_amd64.go:113) is the only _sifields union member without the category doc comment its siblings carry (glibc labels it /* SIGSYS. */).
• Darwin maps __uint32_t to c.Uint (types_darwin_arm64.go:9) while the linux file uses c.Uint32T for the analogous 32-bit field — same width today, purely a cross-file consistency nit.

[fennoai]

llcppg.pub publishes SiginfoT, Sigval, and X__SigvalT as package types, but they are defined only for linux && amd64 (libc_linux_amd64.go). On darwin/arm64 only SigsetT exists, and on other platforms none of these do — so any consumer that references signal.SiginfoT or signal.Sigval will fail to build outside linux/amd64. If this is an intended incremental first step, no change needed; otherwise consider generating the darwin (and other-platform) definitions so the published surface matches what is actually available.

[fennoai]

The doc comment // [???] signal set carries a [???] placeholder artifact that surfaces in godoc. __darwin_sigset_t is simply __uint32_t, so this should read something like // signal set. Worth fixing at the generator so the placeholder is not emitted.