From: Cherry Zhang Date: Fri, 10 Apr 2020 23:13:01 +0000 (-0400) Subject: [dev.link] cmd/link: stop populating lib/unit.Textp X-Git-Tag: go1.15beta1~556^2^2~4 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=14cf804aa047cfdb7be90098d53030773fc1424d;p=gostls13.git [dev.link] cmd/link: stop populating lib/unit.Textp lib.Textp was used for text address assignment and trampoline insertion. Now that it has been converted to using the loader, no need to populate lib.Textp. Port the logic of canonicalizing dupok symbol's package to the loader. unit.Textp was used for DWARF generation, which has also been converted to using the loader. Change-Id: I22d4dd30a52a29dd5b1b7b795d43a19f6215e4ac Reviewed-on: https://go-review.googlesource.com/c/go/+/228140 Run-TryBot: Cherry Zhang TryBot-Result: Gobot Gobot Reviewed-by: Than McIntosh --- diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go index 44eea8429e..d8c11fa4c0 100644 --- a/src/cmd/link/internal/ld/data.go +++ b/src/cmd/link/internal/ld/data.go @@ -413,7 +413,7 @@ func relocsym(target *Target, ldr *loader.Loader, err *ErrorReporter, syms *Arch case objabi.R_ADDRCUOFF: // debug_range and debug_loc elements use this relocation type to get an // offset from the start of the compile unit. - o = Symaddr(r.Sym) + r.Add - Symaddr(r.Sym.Unit.Textp[0]) + o = Symaddr(r.Sym) + r.Add - Symaddr(ldr.Syms[r.Sym.Unit.Textp2[0]]) // r->sym can be null when CALL $(constant) is transformed from absolute PC to relative PC call. case objabi.R_GOTPCREL: diff --git a/src/cmd/link/internal/ld/deadcode.go b/src/cmd/link/internal/ld/deadcode.go index 13ddcdac24..e5bd73cd94 100644 --- a/src/cmd/link/internal/ld/deadcode.go +++ b/src/cmd/link/internal/ld/deadcode.go @@ -5,7 +5,6 @@ package ld import ( - "cmd/internal/objabi" "cmd/link/internal/sym" ) @@ -46,11 +45,9 @@ func deadcode(ctxt *Link) { } // addToTextp populates the context Textp slice (needed in various places -// in the linker) and also the unit Textp slices (needed by the "old" -// phase 2 DWARF generation). +// in the linker). func addToTextp(ctxt *Link) { - - // First set up ctxt.Textp, based on ctxt.Textp2. + // Set up ctxt.Textp, based on ctxt.Textp2. textp := make([]*sym.Symbol, 0, len(ctxt.Textp2)) haveshlibs := len(ctxt.Shlibs) > 0 for _, tsym := range ctxt.Textp2 { @@ -64,37 +61,4 @@ func addToTextp(ctxt *Link) { textp = append(textp, sp) } ctxt.Textp = textp - - // Dupok symbols may be defined in multiple packages; the - // associated package for a dupok sym is chosen sort of - // arbitrarily (the first containing package that the linker - // loads). The loop below canonicalizes the File to the package - // with which it will be laid down in text. Assumes that - // ctxt.Library is already in postorder. - for _, doInternal := range [2]bool{true, false} { - for _, lib := range ctxt.Library { - if isRuntimeDepPkg(lib.Pkg) != doInternal { - continue - } - for _, dsym := range lib.DupTextSyms2 { - tsp := ctxt.loader.Syms[dsym] - if !tsp.Attr.OnList() { - tsp.Attr |= sym.AttrOnList - tsp.File = objabi.PathToPrefix(lib.Pkg) - } - } - } - } - - // Finally, set up compilation unit Textp slices. Can be removed - // once loader-Sym DWARF-gen phase 2 is always enabled. - for _, lib := range ctxt.Library { - for _, unit := range lib.Units { - for _, usym := range unit.Textp2 { - usp := ctxt.loader.Syms[usym] - usp.Attr |= sym.AttrOnList - unit.Textp = append(unit.Textp, usp) - } - } - } } diff --git a/src/cmd/link/internal/loader/loader.go b/src/cmd/link/internal/loader/loader.go index daf91dd258..ff5d8ed322 100644 --- a/src/cmd/link/internal/loader/loader.go +++ b/src/cmd/link/internal/loader/loader.go @@ -1252,10 +1252,10 @@ func (l *Loader) SymUnit(i Sym) *sym.CompilationUnit { // shared library), will hold the library name. // NOTE: this correspondes to sym.Symbol.File field. func (l *Loader) SymPkg(i Sym) string { + if f, ok := l.symPkg[i]; ok { + return f + } if l.IsExternal(i) { - if f, ok := l.symPkg[i]; ok { - return f - } pp := l.getPayload(i) if pp.objidx != 0 { r := l.objs[pp.objidx].r @@ -1275,9 +1275,6 @@ func (l *Loader) SetSymPkg(i Sym, pkg string) { if i >= Sym(len(l.objSyms)) || i == 0 { panic("bad symbol index in SetSymPkg") } - if !l.IsExternal(i) { - panic("can't set file for non-external sym") - } l.symPkg[i] = pkg } @@ -2452,7 +2449,6 @@ func (l *Loader) CreateStaticSym(name string) Sym { } func loadObjFull(l *Loader, r *oReader) { - lib := r.unit.Lib resolveSymRef := func(s goobj2.SymRef) *sym.Symbol { i := l.resolve(r, s) return l.Syms[i] @@ -2463,34 +2459,16 @@ func loadObjFull(l *Loader, r *oReader) { // content will actually be provided by a different object // (to which its global index points). Skip those symbols. gi := l.toGlobal(r, i) - var isdup bool if r2, i2 := l.toLocal(gi); r2 != r || i2 != i { - isdup = true - } - - osym := r.Sym(i) - dupok := osym.Dupok() - if dupok && isdup { - if l.attrReachable.Has(gi) { - // A dupok symbol is resolved to another package. We still need - // to record its presence in the current package, as the trampoline - // pass expects packages are laid out in dependency order. - s := l.Syms[gi] - if s.Type == sym.STEXT { - lib.DupTextSyms = append(lib.DupTextSyms, s) - } - } continue } - - if isdup { - continue // come from a different object - } s := l.Syms[gi] if s == nil { continue } + osym := r.Sym(i) + dupok := osym.Dupok() local := osym.Local() makeTypelink := osym.Typelink() size := osym.Siz() @@ -2711,7 +2689,7 @@ func (l *Loader) AssignTextSymbolOrder(libs []*sym.Library, intlibs []bool, exts } libtextp2 := []sym.LoaderSym{} lists := [2][]sym.LoaderSym{lib.Textp2, lib.DupTextSyms2} - for _, list := range lists { + for i, list := range lists { for _, s := range list { sym := Sym(s) if l.attrReachable.Has(sym) && !assignedToUnit.Has(sym) { @@ -2722,6 +2700,14 @@ func (l *Loader) AssignTextSymbolOrder(libs []*sym.Library, intlibs []bool, exts unit.Textp2 = append(unit.Textp2, s) assignedToUnit.Set(sym) } + // Dupok symbols may be defined in multiple packages; the + // associated package for a dupok sym is chosen sort of + // arbitrarily (the first containing package that the linker + // loads). Canonicalizes its Pkg to the package with which + // it will be laid down in text. + if i == 1 /* DupTextSyms2 */ && l.SymPkg(sym) != lib.Pkg { + l.SetSymPkg(sym, lib.Pkg) + } } } } diff --git a/src/cmd/link/internal/sym/library.go b/src/cmd/link/internal/sym/library.go index 21568dfbe2..bed16565ba 100644 --- a/src/cmd/link/internal/sym/library.go +++ b/src/cmd/link/internal/sym/library.go @@ -13,8 +13,6 @@ type Library struct { Hash string ImportStrings []string Imports []*Library - Textp []*Symbol // text symbols defined in this library - DupTextSyms []*Symbol // dupok text symbols defined in this library Main bool Safe bool Units []*CompilationUnit