cmd/compile: bug in cmd/compile/internal/noder.(*reader).localIdent

[prattmic]

Issue created by stacks.

This stack hs84Kg was reported by telemetry:

• compile/bug
• cmd/compile/internal/base.FatalfAt:+3
• cmd/compile/internal/base.Fatalf:=195
• cmd/compile/internal/gc.handlePanic:+7
• runtime.gopanic:+50
• internal/pkgbits.assert:=11
• internal/pkgbits.(*Decoder).rawReloc:=296
• internal/pkgbits.(*Decoder).Reloc:+2
• internal/pkgbits.(*Decoder).String:+2
• cmd/compile/internal/noder.(*reader).localIdent:=1084
• cmd/compile/internal/noder.(*reader).param:+2
• cmd/compile/internal/noder.(*reader).params:+4
• cmd/compile/internal/noder.(*reader).signature:+4
• cmd/compile/internal/noder.(*reader).method:+6
• cmd/compile/internal/noder.(*pkgReader).objIdxMayFail:+152
• cmd/compile/internal/noder.(*pkgReader).objIdx:+1
• cmd/compile/internal/noder.(*pkgReader).objInstIdx:+8

cmd/compile@go1.23.2 go1.23.2 linux/amd64  (1)

[gabyhelp]

Related Issues

• cmd/compile: bug in cmd/compile/internal/noder.(*pkgReader).objIdxMayFail #70997
• cmd/compile: bug in cmd/compile/internal/importer.(*pkgReader).objIdx.func1 #70996
• cmd/compile: bug in cmd/compile/internal/staticdata.WriteEmbed #70995 (closed)
• cmd/compile: assertion failure when building syntax package with gotypesalias enabled #66873 (closed)
• cmd/compile: Unified IR failed to compile recursive generic type #54722 (closed)
• cmd/compile: unreachable panic with GODEBUG=gotypesalias=1 #65778 (closed)
• cmd/compile: internal compiler error: assertion failed #53762 (closed)
• cmd/compile: crash compiling code with local generic type #50350 (closed)
• cmd/compile: ICE with `assertion failed` when using `GODEBUG=gotypesalias=1` #65893 (closed)
• cmd/compile: range over rune literal causes internal compiler error #64471 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[prattmic]

Many of these issues involve internal/pkgbits decoding. I suspect that they are all related, but I've avoided deduping them thus far because I'm not particularly familiar with export data.

Full set of issues:

• cmd/compile: bug in cmd/compile/internal/noder.(*reader).localIdent #70998
• cmd/compile: bug in cmd/compile/internal/importer.(*reader).pkg #71000
• cmd/compile: bug in cmd/compile/internal/noder.readPackage #71004
• cmd/compile: bug in cmd/compile/internal/importer.(*reader).typInfo #71012
• cmd/compile: bug in cmd/compile/internal/noder.readImportFile #71013
• cmd/compile: bug in cmd/compile/internal/importer.(*pkgReader).newReader #71016
• cmd/compile: bug in cmd/compile/internal/noder.(*pkgReader).posBaseIdx #71017

Others involving export data, but not internal/pkgbits decoding specifically:

• cmd/compile: bug in cmd/compile/internal/importer.(*pkgReader).objIdx.func1 #70996
• cmd/compile: bug in cmd/compile/internal/noder.(*pkgReader).objIdxMayFail #70997
• cmd/compile: bug in cmd/compile/internal/types.NewNamed #71001
• cmd/compile: bug in cmd/compile/internal/noder.(*pkgWriter).pkgIdx #71006 (internal/pkgbits encoding)
• cmd/compile: bug in cmd/compile/internal/types.(*Type).Elem #71008
• cmd/compile: bug in cmd/compile/internal/noder.(*pkgWriter).pkgIdx #71015 (also export data writing)
• cmd/compile: bug in cmd/compile/internal/types.CalcSize #71018
• cmd/compile: bug in cmd/compile/internal/noder.(*reader).doPkg #71019
• cmd/compile: bug in cmd/compile/internal/types.NewField #71021
• cmd/compile: bug in cmd/compile/internal/types.(*Type).wantEtype #71022
• cmd/compile: bug in cmd/compile/internal/noder.(*linker).exportBody #71023 (relocs)
• cmd/compile: bug in cmd/compile/internal/noder.(*reader).typeParamNames #71024