[dev.link] cmd/internal/goobj2, cmd/link: add and use new Sym accessors
Along the line with Reloc and Aux, use new-style accessors for
the Sym type. They avoid reading unnecessary fields, and also
look nicer (to me).
Change-Id: Ie37c5149a6edb2184724b3dfa26952015e74c085
Reviewed-on: https://go-review.googlesource.com/c/go/+/226798
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
diff --git a/src/cmd/internal/goobj2/objfile.go b/src/cmd/internal/goobj2/objfile.go
index db84e8a..54316cd 100644
--- a/src/cmd/internal/goobj2/objfile.go
+++ b/src/cmd/internal/goobj2/objfile.go
@@ -253,6 +253,30 @@
func (s *Sym) IsGoType() bool { return s.Flag&SymFlagGoType != 0 }
func (s *Sym) TopFrame() bool { return s.Flag&SymFlagTopFrame != 0 }
+const SymSize = stringRefSize + 2 + 1 + 1 + 4
+
+type Sym2 [SymSize]byte
+
+func (s *Sym2) Name(r *Reader) string {
+ len := binary.LittleEndian.Uint32(s[:])
+ off := binary.LittleEndian.Uint32(s[4:])
+ return r.StringAt(off, len)
+}
+
+func (s *Sym2) ABI() uint16 { return binary.LittleEndian.Uint16(s[8:]) }
+func (s *Sym2) Type() uint8 { return s[10] }
+func (s *Sym2) Flag() uint8 { return s[11] }
+func (s *Sym2) Siz() uint32 { return binary.LittleEndian.Uint32(s[12:]) }
+
+func (s *Sym2) Dupok() bool { return s.Flag()&SymFlagDupok != 0 }
+func (s *Sym2) Local() bool { return s.Flag()&SymFlagLocal != 0 }
+func (s *Sym2) Typelink() bool { return s.Flag()&SymFlagTypelink != 0 }
+func (s *Sym2) Leaf() bool { return s.Flag()&SymFlagLeaf != 0 }
+func (s *Sym2) NoSplit() bool { return s.Flag()&SymFlagNoSplit != 0 }
+func (s *Sym2) ReflectMethod() bool { return s.Flag()&SymFlagReflectMethod != 0 }
+func (s *Sym2) IsGoType() bool { return s.Flag()&SymFlagGoType != 0 }
+func (s *Sym2) TopFrame() bool { return s.Flag()&SymFlagTopFrame != 0 }
+
// Symbol reference.
type SymRef struct {
PkgIdx uint32
@@ -593,6 +617,12 @@
return r.h.Offsets[BlkSymdef] + uint32(i*symsiz)
}
+// Sym2 returns a pointer to the i-th symbol.
+func (r *Reader) Sym2(i int) *Sym2 {
+ off := r.SymOff(i)
+ return (*Sym2)(unsafe.Pointer(&r.b[off]))
+}
+
// NReloc returns the number of relocations of the i-th symbol.
func (r *Reader) NReloc(i int) int {
relocIdxOff := r.h.Offsets[BlkRelocIdx] + uint32(i*4)
diff --git a/src/cmd/link/internal/loader/loader.go b/src/cmd/link/internal/loader/loader.go
index bf40f5b..5f12874 100644
--- a/src/cmd/link/internal/loader/loader.go
+++ b/src/cmd/link/internal/loader/loader.go
@@ -387,15 +387,14 @@
return oldi, false
}
oldr, oldli := l.toLocal(oldi)
- oldsym := goobj2.Sym{}
- oldsym.ReadWithoutName(oldr.Reader, oldr.SymOff(oldli))
+ oldsym := oldr.Sym2(oldli)
if oldsym.Dupok() {
return oldi, false
}
overwrite := r.DataSize(li) != 0
if overwrite {
// new symbol overwrites old symbol.
- oldtyp := sym.AbiSymKindToSymKind[objabi.SymKind(oldsym.Type)]
+ oldtyp := sym.AbiSymKindToSymKind[objabi.SymKind(oldsym.Type())]
if !(oldtyp.IsData() && oldr.DataSize(oldli) == 0) {
log.Fatalf("duplicated definition of symbol " + name)
}
@@ -617,9 +616,7 @@
return pp.name
}
r, li := l.toLocal(i)
- osym := goobj2.Sym{}
- osym.Read(r.Reader, r.SymOff(li))
- return osym.Name
+ return r.Sym2(li).Name(r.Reader)
}
// Returns the (patched) name of the i-th symbol.
@@ -629,9 +626,7 @@
return pp.name
}
r, li := l.toLocal(i)
- osym := goobj2.Sym{}
- osym.Read(r.Reader, r.SymOff(li))
- return strings.Replace(osym.Name, "\"\".", r.pkgprefix, -1)
+ return strings.Replace(r.Sym2(li).Name(r.Reader), "\"\".", r.pkgprefix, -1)
}
// Returns the version of the i-th symbol.
@@ -641,9 +636,7 @@
return pp.ver
}
r, li := l.toLocal(i)
- osym := goobj2.Sym{}
- osym.ReadWithoutName(r.Reader, r.SymOff(li))
- return int(abiToVer(osym.ABI, r.version))
+ return int(abiToVer(r.Sym2(li).ABI(), r.version))
}
// Returns the type of the i-th symbol.
@@ -656,9 +649,7 @@
return 0
}
r, li := l.toLocal(i)
- osym := goobj2.Sym{}
- osym.ReadWithoutName(r.Reader, r.SymOff(li))
- return sym.AbiSymKindToSymKind[objabi.SymKind(osym.Type)]
+ return sym.AbiSymKindToSymKind[objabi.SymKind(r.Sym2(li).Type())]
}
// Returns the attributes of the i-th symbol.
@@ -668,9 +659,7 @@
return 0
}
r, li := l.toLocal(i)
- osym := goobj2.Sym{}
- osym.ReadFlag(r.Reader, r.SymOff(li))
- return osym.Flag
+ return r.Sym2(li).Flag()
}
// AttrReachable returns true for symbols that are transitively
@@ -772,9 +761,7 @@
// might make more sense to copy the flag value out of the object
// into a larger bitmap during preload.
r, li := l.toLocal(i)
- osym := goobj2.Sym{}
- osym.ReadFlag(r.Reader, r.SymOff(li))
- return osym.Dupok()
+ return r.Sym2(li).Dupok()
}
return l.attrDuplicateOK.Has(l.extIndex(i))
}
@@ -1302,18 +1289,6 @@
return r.NAux(li)
}
-// Returns the referred symbol of the j-th aux symbol of the i-th
-// symbol.
-func (l *Loader) AuxSym(i Sym, j int) Sym {
- if l.IsExternal(i) {
- return 0
- }
- r, li := l.toLocal(i)
- a := goobj2.Aux{}
- a.Read(r.Reader, r.AuxOff(li, j))
- return l.resolve(r, a.Sym)
-}
-
// Returns the "handle" to the j-th aux symbol of the i-th symbol.
func (l *Loader) Aux2(i Sym, j int) Aux2 {
if l.IsExternal(i) {
@@ -1612,12 +1587,11 @@
l.growSyms(len(l.objSyms) + end - start)
l.growAttrBitmaps(len(l.objSyms) + end - start)
for i := start; i < end; i++ {
- osym := goobj2.Sym{}
- osym.Read(r.Reader, r.SymOff(i))
- name := strings.Replace(osym.Name, "\"\".", r.pkgprefix, -1)
- v := abiToVer(osym.ABI, r.version)
+ osym := r.Sym2(i)
+ name := strings.Replace(osym.Name(r.Reader), "\"\".", r.pkgprefix, -1)
+ v := abiToVer(osym.ABI(), r.version)
dupok := osym.Dupok()
- gi, added := l.AddSym(name, v, r, i, kind, dupok, sym.AbiSymKindToSymKind[objabi.SymKind(osym.Type)])
+ gi, added := l.AddSym(name, v, r, i, kind, dupok, sym.AbiSymKindToSymKind[objabi.SymKind(osym.Type())])
r.syms[i] = gi
if !added {
continue
@@ -1659,10 +1633,9 @@
func loadObjRefs(l *Loader, r *oReader, syms *sym.Symbols) {
ndef := r.NSym() + r.NNonpkgdef()
for i, n := 0, r.NNonpkgref(); i < n; i++ {
- osym := goobj2.Sym{}
- osym.Read(r.Reader, r.SymOff(ndef+i))
- name := strings.Replace(osym.Name, "\"\".", r.pkgprefix, -1)
- v := abiToVer(osym.ABI, r.version)
+ osym := r.Sym2(ndef + i)
+ name := strings.Replace(osym.Name(r.Reader), "\"\".", r.pkgprefix, -1)
+ v := abiToVer(osym.ABI(), r.version)
r.syms[ndef+i] = l.LookupOrCreateSym(name, v)
if osym.Local() {
gi := r.syms[ndef+i]
@@ -2079,10 +2052,9 @@
if r2, i2 := l.toLocal(gi); r2 != r || i2 != i {
continue // come from a different object
}
- osym := goobj2.Sym{}
- osym.Read(r.Reader, r.SymOff(i))
- name := strings.Replace(osym.Name, "\"\".", r.pkgprefix, -1)
- t := sym.AbiSymKindToSymKind[objabi.SymKind(osym.Type)]
+ osym := r.Sym2(i)
+ name := strings.Replace(osym.Name(r.Reader), "\"\".", r.pkgprefix, -1)
+ t := sym.AbiSymKindToSymKind[objabi.SymKind(osym.Type())]
// NB: for the test below, we can skip most anonymous symbols
// since they will never be turned into sym.Symbols (ex:
// funcdata), however DWARF subprogram DIE symbols (which are
@@ -2092,7 +2064,7 @@
if name == "" && t != sym.SDWARFINFO {
continue
}
- ver := abiToVer(osym.ABI, r.version)
+ ver := abiToVer(osym.ABI(), r.version)
if t == sym.SXREF {
log.Fatalf("bad sxref")
}
@@ -2117,9 +2089,9 @@
// We use this to delay populating FuncInfo until we can batch-allocate
// slices for their sub-objects.
type funcInfoSym struct {
- s *sym.Symbol // sym.Symbol for a live function
- osym goobj2.Sym // object file symbol data for that function
- isym int // global symbol index of FuncInfo aux sym for func
+ s *sym.Symbol // sym.Symbol for a live function
+ osym *goobj2.Sym2 // object file symbol data for that function
+ isym int // global symbol index of FuncInfo aux sym for func
}
// funcAllocInfo records totals/counts for all functions in an objfile;
@@ -2146,19 +2118,18 @@
l.growSyms(int(symIdx))
// Read the particulars from object.
- osym := goobj2.Sym{}
r, li := l.toLocal(symIdx)
- osym.Read(r.Reader, r.SymOff(li))
- sname := strings.Replace(osym.Name, "\"\".", r.pkgprefix, -1)
- sver := abiToVer(osym.ABI, r.version)
- skind := sym.AbiSymKindToSymKind[objabi.SymKind(osym.Type)]
+ osym := r.Sym2(li)
+ sname := strings.Replace(osym.Name(r.Reader), "\"\".", r.pkgprefix, -1)
+ sver := abiToVer(osym.ABI(), r.version)
+ skind := sym.AbiSymKindToSymKind[objabi.SymKind(osym.Type())]
// Create new symbol, update version and kind.
pi := l.newPayload(sname, sver)
pp := l.payloads[pi]
pp.kind = skind
pp.ver = sver
- pp.size = int64(osym.Siz)
+ pp.size = int64(osym.Siz())
pp.objidx = r.objidx
// If this is a def, then copy the guts. We expect this case
@@ -2346,8 +2317,7 @@
isdup = true
}
- osym := goobj2.Sym{}
- osym.ReadWithoutName(r.Reader, r.SymOff(i))
+ osym := r.Sym2(i)
dupok := osym.Dupok()
if dupok && isdup {
if l.attrReachable.Has(gi) {
@@ -2372,7 +2342,7 @@
local := osym.Local()
makeTypelink := osym.Typelink()
- size := osym.Siz
+ size := osym.Siz()
// Symbol data
s.P = r.Data(i)
@@ -2655,9 +2625,8 @@
if !l.attrReachable.Has(gi) {
continue
}
- osym := goobj2.Sym{}
- osym.ReadWithoutName(r.Reader, r.SymOff(i))
- st := sym.AbiSymKindToSymKind[objabi.SymKind(osym.Type)]
+ osym := r.Sym2(i)
+ st := sym.AbiSymKindToSymKind[objabi.SymKind(osym.Type())]
if st != sym.STEXT {
continue
}
