cmd/link: remove elfsetstring out of the loader

Currently, we pass elfsetstring to the loader as a callback, for
a special case of Addstring. This is only used for ELF when adding
strings to the section header string table. Move the logic to the
caller instead, so the loader would not have this special case.

Change-Id: Icfb91f380fe4ba435985c3019681597932f58242
Reviewed-on: https://go-review.googlesource.com/c/go/+/492718
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>

diff --git a/src/cmd/link/internal/ld/data_test.go b/src/cmd/link/internal/ld/data_test.go
index f91493bc417db47b87f2e0b6c5f024fd494501c1..2c22cfeb014de0f9caee765d63677b0b0369b0d3 100644 (file)
--- a/src/cmd/link/internal/ld/data_test.go
+++ b/src/cmd/link/internal/ld/data_test.go
@@ -14,10 +14,9 @@ import (
 
 func setUpContext(arch *sys.Arch, iself bool, ht objabi.HeadType, bm, lm string) *Link {
        ctxt := linknew(arch)
-       edummy := func(str string, off int) {}
        ctxt.HeadType = ht
        er := loader.ErrorReporter{}
-       ctxt.loader = loader.NewLoader(0, edummy, &er)
+       ctxt.loader = loader.NewLoader(0, &er)
        ctxt.BuildMode.Set(bm)
        ctxt.LinkMode.Set(lm)
        ctxt.IsELF = iself

diff --git a/src/cmd/link/internal/ld/dwarf.go b/src/cmd/link/internal/ld/dwarf.go
index 4eb0baf63c181a7c24ad47070e88352854c3ecf8..d060dda54d800f5ac7a18ba5410aafa36b79d40b 100644 (file)
--- a/src/cmd/link/internal/ld/dwarf.go
+++ b/src/cmd/link/internal/ld/dwarf.go
@@ -2147,21 +2147,20 @@ func (d *dwctxt) collectUnitLocs(u *sym.CompilationUnit) []loader.Sym {
        return syms
 }
 
-/*
- *  Elf.
- */
-func dwarfaddshstrings(ctxt *Link, shstrtab *loader.SymbolBuilder) {
+// Add DWARF section names to the section header string table, by calling add
+// on each name. ELF only.
+func dwarfaddshstrings(ctxt *Link, add func(string)) {
        if *FlagW { // disable dwarf
                return
        }
 
        secs := []string{"abbrev", "frame", "info", "loc", "line", "gdb_scripts", "ranges"}
        for _, sec := range secs {
-               shstrtab.Addstring(".debug_" + sec)
+               add(".debug_" + sec)
                if ctxt.IsExternal() {
-                       shstrtab.Addstring(elfRelType + ".debug_" + sec)
+                       add(elfRelType + ".debug_" + sec)
                } else {
-                       shstrtab.Addstring(".zdebug_" + sec)
+                       add(".zdebug_" + sec)
                }
        }
 }

diff --git a/src/cmd/link/internal/ld/elf.go b/src/cmd/link/internal/ld/elf.go
index cc387da68b1bcebf6fa4a615d0ecd0c980cbf714..713f7739a5bb22752eed329b9bb7295bc9634182 100644 (file)
--- a/src/cmd/link/internal/ld/elf.go
+++ b/src/cmd/link/internal/ld/elf.go
@@ -1390,83 +1390,88 @@ func (ctxt *Link) doelf() {
 
        shstrtab.SetType(sym.SELFROSECT)
 
-       shstrtab.Addstring("")
-       shstrtab.Addstring(".text")
-       shstrtab.Addstring(".noptrdata")
-       shstrtab.Addstring(".data")
-       shstrtab.Addstring(".bss")
-       shstrtab.Addstring(".noptrbss")
-       shstrtab.Addstring(".go.fuzzcntrs")
-       shstrtab.Addstring(".go.buildinfo")
+       shstrtabAddstring := func(s string) {
+               off := shstrtab.Addstring(s)
+               elfsetstring(ctxt, 0, s, int(off))
+       }
+
+       shstrtabAddstring("")
+       shstrtabAddstring(".text")
+       shstrtabAddstring(".noptrdata")
+       shstrtabAddstring(".data")
+       shstrtabAddstring(".bss")
+       shstrtabAddstring(".noptrbss")
+       shstrtabAddstring(".go.fuzzcntrs")
+       shstrtabAddstring(".go.buildinfo")
        if ctxt.IsMIPS() {
-               shstrtab.Addstring(".MIPS.abiflags")
-               shstrtab.Addstring(".gnu.attributes")
+               shstrtabAddstring(".MIPS.abiflags")
+               shstrtabAddstring(".gnu.attributes")
        }
 
        // generate .tbss section for dynamic internal linker or external
        // linking, so that various binutils could correctly calculate
        // PT_TLS size. See https://golang.org/issue/5200.
        if !*FlagD || ctxt.IsExternal() {
-               shstrtab.Addstring(".tbss")
+               shstrtabAddstring(".tbss")
        }
        if ctxt.IsNetbsd() {
-               shstrtab.Addstring(".note.netbsd.ident")
+               shstrtabAddstring(".note.netbsd.ident")
                if *flagRace {
-                       shstrtab.Addstring(".note.netbsd.pax")
+                       shstrtabAddstring(".note.netbsd.pax")
                }
        }
        if ctxt.IsOpenbsd() {
-               shstrtab.Addstring(".note.openbsd.ident")
+               shstrtabAddstring(".note.openbsd.ident")
        }
        if ctxt.IsFreebsd() {
-               shstrtab.Addstring(".note.tag")
+               shstrtabAddstring(".note.tag")
        }
        if len(buildinfo) > 0 {
-               shstrtab.Addstring(".note.gnu.build-id")
+               shstrtabAddstring(".note.gnu.build-id")
        }
        if *flagBuildid != "" {
-               shstrtab.Addstring(".note.go.buildid")
+               shstrtabAddstring(".note.go.buildid")
        }
-       shstrtab.Addstring(".elfdata")
-       shstrtab.Addstring(".rodata")
+       shstrtabAddstring(".elfdata")
+       shstrtabAddstring(".rodata")
        // See the comment about data.rel.ro.FOO section names in data.go.
        relro_prefix := ""
        if ctxt.UseRelro() {
-               shstrtab.Addstring(".data.rel.ro")
+               shstrtabAddstring(".data.rel.ro")
                relro_prefix = ".data.rel.ro"
        }
-       shstrtab.Addstring(relro_prefix + ".typelink")
-       shstrtab.Addstring(relro_prefix + ".itablink")
-       shstrtab.Addstring(relro_prefix + ".gosymtab")
-       shstrtab.Addstring(relro_prefix + ".gopclntab")
+       shstrtabAddstring(relro_prefix + ".typelink")
+       shstrtabAddstring(relro_prefix + ".itablink")
+       shstrtabAddstring(relro_prefix + ".gosymtab")
+       shstrtabAddstring(relro_prefix + ".gopclntab")
 
        if ctxt.IsExternal() {
                *FlagD = true
 
-               shstrtab.Addstring(elfRelType + ".text")
-               shstrtab.Addstring(elfRelType + ".rodata")
-               shstrtab.Addstring(elfRelType + relro_prefix + ".typelink")
-               shstrtab.Addstring(elfRelType + relro_prefix + ".itablink")
-               shstrtab.Addstring(elfRelType + relro_prefix + ".gosymtab")
-               shstrtab.Addstring(elfRelType + relro_prefix + ".gopclntab")
-               shstrtab.Addstring(elfRelType + ".noptrdata")
-               shstrtab.Addstring(elfRelType + ".data")
+               shstrtabAddstring(elfRelType + ".text")
+               shstrtabAddstring(elfRelType + ".rodata")
+               shstrtabAddstring(elfRelType + relro_prefix + ".typelink")
+               shstrtabAddstring(elfRelType + relro_prefix + ".itablink")
+               shstrtabAddstring(elfRelType + relro_prefix + ".gosymtab")
+               shstrtabAddstring(elfRelType + relro_prefix + ".gopclntab")
+               shstrtabAddstring(elfRelType + ".noptrdata")
+               shstrtabAddstring(elfRelType + ".data")
                if ctxt.UseRelro() {
-                       shstrtab.Addstring(elfRelType + ".data.rel.ro")
+                       shstrtabAddstring(elfRelType + ".data.rel.ro")
                }
-               shstrtab.Addstring(elfRelType + ".go.buildinfo")
+               shstrtabAddstring(elfRelType + ".go.buildinfo")
                if ctxt.IsMIPS() {
-                       shstrtab.Addstring(elfRelType + ".MIPS.abiflags")
-                       shstrtab.Addstring(elfRelType + ".gnu.attributes")
+                       shstrtabAddstring(elfRelType + ".MIPS.abiflags")
+                       shstrtabAddstring(elfRelType + ".gnu.attributes")
                }
 
                // add a .note.GNU-stack section to mark the stack as non-executable
-               shstrtab.Addstring(".note.GNU-stack")
+               shstrtabAddstring(".note.GNU-stack")
 
                if ctxt.IsShared() {
-                       shstrtab.Addstring(".note.go.abihash")
-                       shstrtab.Addstring(".note.go.pkg-list")
-                       shstrtab.Addstring(".note.go.deps")
+                       shstrtabAddstring(".note.go.abihash")
+                       shstrtabAddstring(".note.go.pkg-list")
+                       shstrtabAddstring(".note.go.deps")
                }
        }
 
@@ -1479,35 +1484,35 @@ func (ctxt *Link) doelf() {
        }
 
        if hasinitarr {
-               shstrtab.Addstring(".init_array")
-               shstrtab.Addstring(elfRelType + ".init_array")
+               shstrtabAddstring(".init_array")
+               shstrtabAddstring(elfRelType + ".init_array")
        }
 
        if !*FlagS {
-               shstrtab.Addstring(".symtab")
-               shstrtab.Addstring(".strtab")
-               dwarfaddshstrings(ctxt, shstrtab)
+               shstrtabAddstring(".symtab")
+               shstrtabAddstring(".strtab")
+               dwarfaddshstrings(ctxt, shstrtabAddstring)
        }
 
-       shstrtab.Addstring(".shstrtab")
+       shstrtabAddstring(".shstrtab")
 
        if !*FlagD { /* -d suppresses dynamic loader format */
-               shstrtab.Addstring(".interp")
-               shstrtab.Addstring(".hash")
-               shstrtab.Addstring(".got")
+               shstrtabAddstring(".interp")
+               shstrtabAddstring(".hash")
+               shstrtabAddstring(".got")
                if ctxt.IsPPC64() {
-                       shstrtab.Addstring(".glink")
-               }
-               shstrtab.Addstring(".got.plt")
-               shstrtab.Addstring(".dynamic")
-               shstrtab.Addstring(".dynsym")
-               shstrtab.Addstring(".dynstr")
-               shstrtab.Addstring(elfRelType)
-               shstrtab.Addstring(elfRelType + ".plt")
-
-               shstrtab.Addstring(".plt")
-               shstrtab.Addstring(".gnu.version")
-               shstrtab.Addstring(".gnu.version_r")
+                       shstrtabAddstring(".glink")
+               }
+               shstrtabAddstring(".got.plt")
+               shstrtabAddstring(".dynamic")
+               shstrtabAddstring(".dynsym")
+               shstrtabAddstring(".dynstr")
+               shstrtabAddstring(elfRelType)
+               shstrtabAddstring(elfRelType + ".plt")
+
+               shstrtabAddstring(".plt")
+               shstrtabAddstring(".gnu.version")
+               shstrtabAddstring(".gnu.version_r")
 
                /* dynamic symbol table - first entry all zeros */
                dynsym := ldr.CreateSymForUpdate(".dynsym", 0)

diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index 03b13da37a5b64ec822f27fa3b88f448eaca325e..0febb3081f7d144581a9ca42ac6dfe14137ff82e 100644 (file)
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -528,8 +528,7 @@ func (ctxt *Link) loadlib() {
        default:
                log.Fatalf("invalid -strictdups flag value %d", *FlagStrictDups)
        }
-       elfsetstring1 := func(str string, off int) { elfsetstring(ctxt, 0, str, off) }
-       ctxt.loader = loader.NewLoader(flags, elfsetstring1, &ctxt.ErrorReporter.ErrorReporter)
+       ctxt.loader = loader.NewLoader(flags, &ctxt.ErrorReporter.ErrorReporter)
        ctxt.ErrorReporter.SymName = func(s loader.Sym) string {
                return ctxt.loader.SymName(s)
        }

diff --git a/src/cmd/link/internal/loader/loader.go b/src/cmd/link/internal/loader/loader.go
index fa74dcede423038c9ef363fa72aaa54d02b35666..f4b075b07708c6408b85fc8dc6e842f3a7065f92 100644 (file)
--- a/src/cmd/link/internal/loader/loader.go
+++ b/src/cmd/link/internal/loader/loader.go
@@ -261,8 +261,6 @@ type Loader struct {
 
        strictDupMsgs int // number of strict-dup warning/errors, when FlagStrictDups is enabled
 
-       elfsetstring elfsetstringFunc
-
        errorReporter *ErrorReporter
 
        npkgsyms    int // number of package symbols, for accounting
@@ -284,8 +282,6 @@ const (
        goObjStart
 )
 
-type elfsetstringFunc func(str string, off int)
-
 // extSymPayload holds the payload (data + relocations) for linker-synthesized
 // external symbols (note that symbol value is stored in a separate slice).
 type extSymPayload struct {
@@ -304,7 +300,7 @@ const (
        FlagStrictDups = 1 << iota
 )
 
-func NewLoader(flags uint32, elfsetstring elfsetstringFunc, reporter *ErrorReporter) *Loader {
+func NewLoader(flags uint32, reporter *ErrorReporter) *Loader {
        nbuiltin := goobj.NBuiltin()
        extReader := &oReader{objidx: extObj}
        ldr := &Loader{
@@ -333,7 +329,6 @@ func NewLoader(flags uint32, elfsetstring elfsetstringFunc, reporter *ErrorRepor
                extStaticSyms:        make(map[nameVer]Sym),
                builtinSyms:          make([]Sym, nbuiltin),
                flags:                flags,
-               elfsetstring:         elfsetstring,
                errorReporter:        reporter,
                sects:                []*sym.Section{nil}, // reserve index 0 for nil section
        }

diff --git a/src/cmd/link/internal/loader/loader_test.go b/src/cmd/link/internal/loader/loader_test.go
index 8ee4be033b7f76be49c5e48b7d32ac3683f7139d..32ff2586cebfb71f5a9f77c8a9912d71915825c0 100644 (file)
--- a/src/cmd/link/internal/loader/loader_test.go
+++ b/src/cmd/link/internal/loader/loader_test.go
@@ -26,9 +26,8 @@ func addDummyObjSym(t *testing.T, ldr *Loader, or *oReader, name string) Sym {
 }
 
 func mkLoader() *Loader {
-       edummy := func(str string, off int) {}
        er := ErrorReporter{}
-       ldr := NewLoader(0, edummy, &er)
+       ldr := NewLoader(0, &er)
        er.ldr = ldr
        return ldr
 }

diff --git a/src/cmd/link/internal/loader/symbolbuilder.go b/src/cmd/link/internal/loader/symbolbuilder.go
index 1744df2784e744c751e4e35920a8ca13eb744fde..5a3e88b90eb09e2018d8ca0d11e49245b9c277d5 100644 (file)
--- a/src/cmd/link/internal/loader/symbolbuilder.go
+++ b/src/cmd/link/internal/loader/symbolbuilder.go
@@ -332,10 +332,6 @@ func (sb *SymbolBuilder) Addstring(str string) int64 {
                sb.kind = sym.SNOPTRDATA
        }
        r := sb.size
-       if sb.name == ".shstrtab" {
-               // FIXME: find a better mechanism for this
-               sb.l.elfsetstring(str, int(r))
-       }
        sb.data = append(sb.data, str...)
        sb.data = append(sb.data, 0)
        sb.size = int64(len(sb.data))