test/goroot: expand Go 1.26 compiler coverage#2063
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Replaces the size-class counters with gc-shaped heap profiling: sampled allocations are attributed to physical call stacks at exact statement lines, and records hold RAW sampled counts — consumers (pprof, goroot heapsampling.go) apply the Poisson correction themselves, exactly as with gc. - Sampling mirrors gc's mcache.nextSample: bytes count down to an exponentially distributed threshold (mean MemProfileRate), sample once on crossing, redraw. The memoryless distribution is load-bearing: with any bounded-support threshold a near-periodic allocation pattern phase-locks the sample points onto the large sites (observed 1.6x per-site skew on heapsampling's interleaved sizes). ln() is a small local approximation — the runtime core cannot import math. - Stacks come from the FP walk at sample time (fpCallers via a hook the public runtime registers), bucketed by stack hash; allocator plumbing (including __llgo_stub. wrapper frames of the hook) is trimmed at read time. A reentrancy flag spans the whole decision path: threshold drawing and bucket allocation themselves allocate, and a recursive sample overflows the stack. - Heap allocations get statement anchors in tracked functions, and a package that reads the memory profile (runtime.MemProfile / MemProfileRate under either the "runtime" or the patched lib-runtime spelling) pins all its trackable functions: per-site attribution loses sites to inlining otherwise. Profiling packages are rare and accuracy beats inlining there; gc gets both via its inline tree (P4). goroot heapsampling.go passes on darwin/arm64 and linux/arm64 (the latter was a pre-existing platform gap). Depends on --icf=none from the line-directive PR: heapsampling's three identical wrapper functions must keep distinct pcs. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
…upport Re-expresses the surviving value of xgo-dev#1892 on the xgo-dev#2023 base (its other ~10k lines were an earlier draft of the funcinfo/pclntab machinery, since superseded by xgo-dev#2012/xgo-dev#2016/xgo-dev#2019): - //go:nointerface methods no longer satisfy interfaces: the pragma is recorded at import (cl/import.go -> Program.SetNoInterfaceMethod) and filtered out of abi uncommon method tables; GlobalDCE metadata takes the filtered selection list. Retires the typeparam/mdempsky/15 goroot xfails (validated go1.26 darwin, ci directive mode). - Type-assertion failure between same-named types from different scopes appends '(types from different scopes)' (gc wording). - MatchesClosure unwraps closure types on both sides, fixing assertions between closure and plain function types. - reflect.(*rtype).Method builds the method func value with the closure layout allocation (fixes reflect method-value identity). - xfail: retire fixedbugs/issue16130, fixedbugs/issue29735 (validated go1.24 + go1.26 darwin), and reword typeparam/mdempsky/16 - the panic value now implements runtime.Error; the message still lacks the source interface type and prints the command-line-arguments package path.
Re-expresses xgo-dev#1918 on the xgo-dev#2023 base (its remaining ~11k diff lines were the pre-xgo-dev#2012 funcinfo draft, superseded by the stage-5 chain): - recover() only succeeds when called directly by a deferred function (gc semantics): the panic node records the owning Defer frame at rethrow (panicKey/panicNode + GoDeferData), and Recover checks the caller is that frame's direct deferred call. Closure wraps carry StartRecoverFrameAlias/EndRecoverFrame so method-value and closure adapters stay transparent to the ownership check. - Rethrow keeps the xgo-dev#2023 PanicTraceback hook on the unrecovered path. - xfail: retire fixedbugs/issue4066 (2m-timeout entries; now runs in ~2.7s), fixedbugs/issue73916 and issue73916b (go1.26 recover semantics), validated on darwin/arm64 go1.26. Supersedes xgo-dev#1918.
…s; recover conformance Re-expresses the surviving value of xgo-dev#1882 on top of xgo-dev#2033 (its remaining ~11k diff lines were the pre-xgo-dev#2012 funcinfo draft, superseded): - Failed (non-comma-ok) type assertions panic with a real *runtime.TypeAssertionError built at runtime (TypeAssertError + missing-method lookup from abi tables) instead of a plain errorString; the recovered value implements runtime.Error, matching gc. The source-interface abi type is deliberately not materialized at the assert site: doing so can reference another package's private local-generic symbols (undefined at link); the message's interface name is the documented mdempsky/16 residual. - SIGBUS joins SIGSEGV in the fault-to-panic signal path (per-OS signal constants; darwin/linux). - goroot xfails retired, validated darwin go1.26 + go1.24: recover2.go, recover4.go, zerodivide.go, fixedbugs/issue73917.go, issue73920.go. - recover1.go stays xfailed with an updated reason (recursive-panic sub-call recover masking - Defer-node model follow-up); three ported tests covering the same class are t.Skip'ed with that pointer. - Golden CHECK updates: assert-failure sites now emit TypeAssertError+Panic; constants renumbered from actual IR. Supersedes xgo-dev#1882.
Re-expresses xgo-dev#1906 on the xgo-dev#2023 base (its remaining ~11k diff lines were the pre-xgo-dev#2012 funcinfo draft, superseded by the stage-5 chain): - cl gains a liveness analysis for stack-allocated objects: allocas whose last use has passed are cleared so bdwgc's conservative stack scan stops keeping dead stack objects (and what they point to) alive; pointer registers are clobbered around the trigger points (llgo_clobber_pointer_regs) and dead stack slots holding the target are zeroed (llgo_clear_stack_ptr, pthread stack-bounds walk). - runtime.SetFinalizer paths (mfinal, runtime_gc, bdwgc binding) hook the cleared-slot machinery so finalizers for dead stack objects run. - xfail: retire deferfin.go, stackobj.go, stackobj3.go, validated on darwin/arm64 go1.24 + go1.26 (stackobj2 already passed). Carries the xgo-dev#2035 shared-GOCACHE commit temporarily (same patch-id, auto-dedups when the chain rebases after xgo-dev#2035 merges). Supersedes xgo-dev#1906.
With the shared go-build cache the four heavy test packages (cl, ssa, internal/cabi, test/go) no longer stagger naturally on cold caches; their compile phases overlap fully, and the burst of concurrent clang/lld children has been killing ubuntu runners mid-run (three consecutive 'runner received a shutdown signal' deaths on this branch, each ~8 minutes into the heavy-package phase) and showing up on mac as go-list WaitDelay expirations. -p 2 caps the concurrent package count; wall time is dominated by the cl package either way.
An acceptance regression asserts exact per-line attribution at rate=1 (raw counts are exact there), and a cl unit test covers the memprofile-package pinning criterion under both runtime spellings. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
… capture path The frame-table init allocates; when one of those allocations crossed the sampling threshold, captureMemProfileStack -> fpCallers re-entered initRuntimeFuncPCFramesSlow on the thread that already held the Busy latch and usleep-spun forever. First testing.callerName call of a test binary triggers the init, so whole test binaries hung at startup — which packages hit it depends on the deterministic threshold sequence meeting the binary's pre-init allocation volume: net/rpc and net/rpc/jsonrpc under go1.24 stdlib, net/http/expvar/cookiejar under go1.26 (CI shard timeouts on ubuntu, both attempts). Entering an Uninit latch from the capture path is safe (the whole sample runs under memProfileInSample, so init's own allocations cannot re-sample); only Busy must not be waited on. Drop that one sample.
…ks see the panic frames gc runs deferred functions on top of the panicked stack; LLGo's longjmp unwinding removes those frames physically, so runtime.Caller / CallersFrames / debug.Stack from a deferred function (before or after recover) could not see the panic site. Now: - Panic() captures the physical pc chain (the existing SavePanicCallerFrames hook, empty since the shadow stack left) into a per-thread snapshot; Recover() marks the recovering frame so the snapshot stays observable exactly while that frame is live. - Caller-info walks splice the snapshot below the live deferred frames at the defer-owner junction, keeping one panic-machinery frame where gc has runtime.gopanic (fixed Caller depths count it). - Hardware faults (SIGSEGV/SIGBUS and previously-fatal SIGFPE) install a SA_SIGINFO handler that captures from the interrupted ucontext pc/fp — the handler's own chain dead-ends at the signal trampoline — so fault tracebacks start at the fault site, through C frames into the Go callers. C is compiled with -fno-omit-frame-pointer so x86-64 chains hold. - Defer execution is attributed to the function's closing brace like gc, and explicit panic statements get their own statement anchor. Signal-path robustness (the reflectmake flake, ~7% -> 0 over 300 runs): - The recover mark reads the frame-pointer chain, which after siglongjmp can reach a stale/unmapped slot; the guarded read (msync page probe) lives in the public runtime via a RecoverMark hook, and the core just calls it — an unguarded read self-faulted and corrupted the value the recover was extracting. - The fault handler does no async-signal-unsafe work: the snapshot buffer is preallocated (no bdwgc malloc in signal context) and the page size is primed at install (no sysconf). SA_NODEFER + an unblock on capture keep a savemask=0 longjmp escape from leaving the fault signal blocked, and a re-entered handler restores the default disposition for one clean core; fault-context walks probe page readability before dereferencing. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Remove issue14646/issue5856/issue33724 xfails; the C-fault regression runs three sequential faults (a handler leaving the signal blocked after the longjmp escape cores on the second) and asserts the fault-site chain. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
…o codex/stage5-integrate-current
…dex/stage5-integrate-current # Conflicts: # runtime/internal/lib/runtime/unwind_llgo.go
…dex/stage5-integrate-current
… codex/stage5-integrate-current # Conflicts: # runtime/internal/runtime/z_rt.go # test/goroot/xfail.yaml
…o codex/stage5-integrate-current # Conflicts: # test/goroot/xfail.yaml
… into codex/stage5-integrate-current # Conflicts: # runtime/internal/lib/runtime/_wrap/runtime.c # test/goroot/xfail.yaml
…te-current # Conflicts: # cl/_testgo/abimethod/in.go # cl/_testgo/tpinst/main.go
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Closing this premature draft. Coverage implementation and per-case local validation will be completed before the branch is pushed and a replacement draft PR is opened. |
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Summary
This draft starts the Go 1.26 GOROOT coverage work tracked in #2062 on top of the merged Stage 5 integration branch.
The current commits establish and verify the merged runtime/compiler baseline, retire stale expectations, and classify the remaining Darwin failures before adding new directive support.
Current Go 1.26
darwin/arm64inventory:compileerrorcheckerrorcheckandrundircasesAll Go language, runtime, ABI, standard-library, compile-only, diagnostic, and hybrid diagnostic/run cases are in scope. Exclusions must be limited to audited Go-compiler-specific implementation tests and documented explicitly.
Base integration
This branch is based on the local integration of:
xgo-dev/mainCurrent changes
fixedbugs/bug449.go;Planned coverage work
compiledirective execution without linking or requiring an executable artifact.errorcheckdiagnostic and source-position matching.errorcheckandrundircoverage: diagnostics first, then link/run/output verification.rundir,runindir, andbuildrundircases.Verification completed so far
GOMAXPROCS=2,-p 1, nice priority, sharding, and per-step timeouts.Draft: implementation and coverage classification are still in progress.
Refs #2062