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[dev.link] cmd/link: remove loader.Reloc

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We have Reloc and Reloc2. Reloc2 is the better approach and most
code uses Reloc2. There are still uses of Reloc. This CL migrates
them to Reloc2, and removes Reloc.

Change-Id: Id5f6a6019e1e044add682d05e70ebb1548ec58d9
Reviewed-on: https://go-review.googlesource.com/c/go/+/245577
Reviewed-by: Jeremy Faller <jeremy@golang.org>
This commit is contained in:
Cherry Zhang 2020-07-29 13:20:56 -04:00
parent 317c1ca9f2
commit 80b287fd28
10 changed files with 129 additions and 205 deletions
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69
src/cmd/link/internal/arm/asm.go
View file

@ -75,25 +75,19 @@ func gentext(ctxt *ld.Link, ldr *loader.Loader) {
o(0xe08f0000)
o(0xeafffffe)
rel := loader.Reloc{
Off: 8,
Size: 4,
Type: objabi.R_CALLARM,
Sym: addmoduledata,
Add: 0xeafffffe, // vomit
}
initfunc.AddReloc(rel)
rel, _ := initfunc.AddRel(objabi.R_CALLARM)
rel.SetOff(8)
rel.SetSiz(4)
rel.SetSym(addmoduledata)
rel.SetAdd(0xeafffffe) // vomit
o(0x00000000)
rel2 := loader.Reloc{
Off: 12,
Size: 4,
Type: objabi.R_PCREL,
Sym: ctxt.Moduledata,
Add: 4,
}
initfunc.AddReloc(rel2)
rel2, _ := initfunc.AddRel(objabi.R_PCREL)
rel2.SetOff(12)
rel2.SetSiz(4)
rel2.SetSym(ctxt.Moduledata)
rel2.SetAdd(4)
}
// Preserve highest 8 bits of a, and do addition to lower 24-bit
@ -452,14 +446,11 @@ func gentramp(arch *sys.Arch, linkmode ld.LinkMode, ldr *loader.Loader, tramp *l
tramp.SetData(P)
if linkmode == ld.LinkExternal {
r := loader.Reloc{
Off: 8,
Type: objabi.R_ADDR,
Size: 4,
Sym: target,
Add: offset,
}
tramp.AddReloc(r)
r, _ := tramp.AddRel(objabi.R_ADDR)
r.SetOff(8)
r.SetSiz(4)
r.SetSym(target)
r.SetAdd(offset)
}
}
@ -477,14 +468,11 @@ func gentramppic(arch *sys.Arch, tramp *loader.SymbolBuilder, target loader.Sym,
arch.ByteOrder.PutUint32(P[12:], o4)
tramp.SetData(P)
r := loader.Reloc{
Off: 12,
Type: objabi.R_PCREL,
Size: 4,
Sym: target,
Add: offset + 4,
}
tramp.AddReloc(r)
r, _ := tramp.AddRel(objabi.R_PCREL)
r.SetOff(12)
r.SetSiz(4)
r.SetSym(target)
r.SetAdd(offset + 4)
}
// generate a trampoline to target+offset in dynlink mode (using GOT)
@ -515,19 +503,16 @@ func gentrampdyn(arch *sys.Arch, tramp *loader.SymbolBuilder, target loader.Sym,
}
tramp.SetData(P)
r := loader.Reloc{
Off: 16,
Type: objabi.R_GOTPCREL,
Size: 4,
Sym: target,
Add: 8,
}
r, _ := tramp.AddRel(objabi.R_GOTPCREL)
r.SetOff(16)
r.SetSiz(4)
r.SetSym(target)
r.SetAdd(8)
if offset != 0 {
// increase reloc offset by 4 as we inserted an ADD instruction
r.Off = 20
r.Add = 12
r.SetOff(20)
r.SetAdd(12)
}
tramp.AddReloc(r)
}
func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loader.Reloc2, s loader.Sym, val int64) (o int64, nExtReloc int, ok bool) {

22
src/cmd/link/internal/arm64/asm.go
View file

@ -56,24 +56,18 @@ func gentext(ctxt *ld.Link, ldr *loader.Loader) {
// 4: R_AARCH64_ADD_ABS_LO12_NC local.moduledata
o(0x90000000)
o(0x91000000)
rel := loader.Reloc{
Off: 0,
Size: 8,
Type: objabi.R_ADDRARM64,
Sym: ctxt.Moduledata,
}
initfunc.AddReloc(rel)
rel, _ := initfunc.AddRel(objabi.R_ADDRARM64)
rel.SetOff(0)
rel.SetSiz(8)
rel.SetSym(ctxt.Moduledata)
// 8: 14000000 b 0 <runtime.addmoduledata>
// 8: R_AARCH64_CALL26 runtime.addmoduledata
o(0x14000000)
rel2 := loader.Reloc{
Off: 8,
Size: 4,
Type: objabi.R_CALLARM64, // Really should be R_AARCH64_JUMP26 but doesn't seem to make any difference
Sym: addmoduledata,
}
initfunc.AddReloc(rel2)
rel2, _ := initfunc.AddRel(objabi.R_CALLARM64)
rel2.SetOff(8)
rel2.SetSiz(4)
rel2.SetSym(addmoduledata)
}
func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym, r loader.Reloc2, rIdx int) bool {

2
src/cmd/link/internal/ld/data.go
View file

@ -1063,7 +1063,7 @@ func addstrdata(arch *sys.Arch, l *loader.Loader, name, value string) {
bld.SetSize(0)
bld.SetData(make([]byte, 0, arch.PtrSize*2))
bld.SetReadOnly(false)
bld.SetRelocs(nil)
bld.ResetRelocs()
bld.AddAddrPlus(arch, sbld.Sym(), 0)
bld.AddUint(arch, uint64(len(value)))
}

3
src/cmd/link/internal/ld/lib.go
View file

@ -2106,7 +2106,8 @@ func ldshlibsyms(ctxt *Link, shlib string) {
}
su := l.MakeSymbolUpdater(alias)
su.SetType(sym.SABIALIAS)
su.AddReloc(loader.Reloc{Sym: s})
r, _ := su.AddRel(0) // type doesn't matter
r.SetSym(s)
}
}
ctxt.Shlibs = append(ctxt.Shlibs, Shlib{Path: libpath, Hash: hash, Deps: deps, File: f})

4
src/cmd/link/internal/ld/pe.go
View file

@ -1115,7 +1115,9 @@ func initdynimport(ctxt *Link) *Dll {
}
dynSym := ldr.CreateSymForUpdate(dynName, 0)
dynSym.SetType(sym.SHOSTOBJ)
sb.AddReloc(loader.Reloc{Sym: dynSym.Sym(), Type: objabi.R_ADDR, Off: 0, Size: uint8(ctxt.Arch.PtrSize)})
r, _ := sb.AddRel(objabi.R_ADDR)
r.SetSym(dynSym.Sym())
r.SetSiz(uint8(ctxt.Arch.PtrSize))
}
}
} else {

4
src/cmd/link/internal/ld/xcoff.go
View file

@ -1201,7 +1201,9 @@ func (f *xcoffFile) adddynimpsym(ctxt *Link, s loader.Sym) {
// Relocation to retrieve the external address
sb.AddBytes(make([]byte, 8))
sb.AddReloc(loader.Reloc{Off: 0, Size: uint8(ctxt.Arch.PtrSize), Type: objabi.R_ADDR, Sym: extsym.Sym()})
r, _ := sb.AddRel(objabi.R_ADDR)
r.SetSym(extsym.Sym())
r.SetSiz(uint8(ctxt.Arch.PtrSize))
// TODO: maybe this could be
// sb.SetSize(0)
// sb.SetData(nil)

19
src/cmd/link/internal/loader/loader.go
View file

@ -37,17 +37,6 @@ type Relocs struct {
l *Loader // loader
}
// Reloc contains the payload for a specific relocation.
// TODO: replace this with sym.Reloc, once we change the
// relocation target from "*sym.Symbol" to "loader.Sym" in sym.Reloc.
type Reloc struct {
Off int32 // offset to rewrite
Size uint8 // number of bytes to rewrite: 0, 1, 2, or 4
Type objabi.RelocType // the relocation type
Add int64 // addend
Sym Sym // global index of symbol the reloc addresses
}
// ExtReloc contains the payload for an external relocation.
type ExtReloc struct {
Xsym Sym
@ -1859,14 +1848,6 @@ func (l *Loader) relocs(r *oReader, li uint32) Relocs {
}
}
// RelocByOff implements sort.Interface for sorting relocations by offset.
type RelocByOff []Reloc
func (x RelocByOff) Len() int { return len(x) }
func (x RelocByOff) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x RelocByOff) Less(i, j int) bool { return x[i].Off < x[j].Off }
// FuncInfo provides hooks to access goobj2.FuncInfo in the objects.
type FuncInfo struct {
l *Loader

49
src/cmd/link/internal/loader/loader_test.go
View file

@ -163,12 +163,18 @@ func TestAddMaterializedSymbol(t *testing.T) {
}
// Add some relocations to the new symbols.
r1 := Reloc{0, 1, objabi.R_ADDR, 0, ts1}
r2 := Reloc{3, 8, objabi.R_CALL, 0, ts2}
r3 := Reloc{7, 1, objabi.R_USETYPE, 0, ts3}
sb1.AddReloc(r1)
sb1.AddReloc(r2)
sb2.AddReloc(r3)
r1, _ := sb1.AddRel(objabi.R_ADDR)
r1.SetOff(0)
r1.SetSiz(1)
r1.SetSym(ts1)
r2, _ := sb1.AddRel(objabi.R_CALL)
r2.SetOff(3)
r2.SetSiz(8)
r2.SetSym(ts2)
r3, _ := sb2.AddRel(objabi.R_USETYPE)
r3.SetOff(7)
r3.SetSiz(1)
r3.SetSym(ts3)
// Add some data to the symbols.
d1 := []byte{1, 2, 3}
@ -179,7 +185,7 @@ func TestAddMaterializedSymbol(t *testing.T) {
// Now invoke the usual loader interfaces to make sure
// we're getting the right things back for these symbols.
// First relocations...
expRel := [][]Reloc{[]Reloc{r1, r2}, []Reloc{r3}}
expRel := [][]Reloc2{{r1, r2}, {r3}}
for k, sb := range []*SymbolBuilder{sb1, sb2} {
rsl := sb.Relocs()
exp := expRel[k]
@ -213,18 +219,18 @@ func TestAddMaterializedSymbol(t *testing.T) {
}
}
func sameRelocSlice(s1 *Relocs, s2 []Reloc) bool {
func sameRelocSlice(s1 *Relocs, s2 []Reloc2) bool {
if s1.Count() != len(s2) {
return false
}
for i := 0; i < s1.Count(); i++ {
r1 := s1.At2(i)
r2 := &s2[i]
if r1.Sym() != r2.Sym ||
r1.Type() != r2.Type ||
r1.Off() != r2.Off ||
r1.Add() != r2.Add ||
r1.Siz() != r2.Size {
if r1.Sym() != r2.Sym() ||
r1.Type() != r2.Type() ||
r1.Off() != r2.Off() ||
r1.Add() != r2.Add() ||
r1.Siz() != r2.Siz() {
return false
}
}
@ -233,6 +239,15 @@ func sameRelocSlice(s1 *Relocs, s2 []Reloc) bool {
type addFunc func(l *Loader, s Sym, s2 Sym) Sym
func mkReloc(l *Loader, typ objabi.RelocType, off int32, siz uint8, add int64, sym Sym) Reloc2 {
r := Reloc2{&goobj2.Reloc{}, l.extReader, l, typ}
r.SetOff(off)
r.SetSiz(siz)
r.SetAdd(add)
r.SetSym(sym)
return r
}
func TestAddDataMethods(t *testing.T) {
ldr := mkLoader()
dummyOreader := oReader{version: -1, syms: make([]Sym, 100)}
@ -248,7 +263,7 @@ func TestAddDataMethods(t *testing.T) {
addDataFunc addFunc
expData []byte
expKind sym.SymKind
expRel []Reloc
expRel []Reloc2
}{
{
which: "AddUint8",
@ -301,7 +316,7 @@ func TestAddDataMethods(t *testing.T) {
},
expData: []byte{0, 0, 0, 0, 0, 0, 0, 0},
expKind: sym.SDATA,
expRel: []Reloc{Reloc{Type: objabi.R_ADDR, Size: 8, Add: 3, Sym: 6}},
expRel: []Reloc2{mkReloc(ldr, objabi.R_ADDR, 0, 8, 3, 6)},
},
{
which: "AddAddrPlus4",
@ -312,7 +327,7 @@ func TestAddDataMethods(t *testing.T) {
},
expData: []byte{0, 0, 0, 0},
expKind: sym.SDATA,
expRel: []Reloc{Reloc{Type: objabi.R_ADDR, Size: 4, Add: 3, Sym: 7}},
expRel: []Reloc2{mkReloc(ldr, objabi.R_ADDR, 0, 4, 3, 7)},
},
{
which: "AddCURelativeAddrPlus",
@ -323,7 +338,7 @@ func TestAddDataMethods(t *testing.T) {
},
expData: []byte{0, 0, 0, 0, 0, 0, 0, 0},
expKind: sym.SDATA,
expRel: []Reloc{Reloc{Type: objabi.R_ADDRCUOFF, Size: 8, Add: 7, Sym: 8}},
expRel: []Reloc2{mkReloc(ldr, objabi.R_ADDRCUOFF, 0, 8, 7, 8)},
},
}

64
src/cmd/link/internal/loader/symbolbuilder.go
View file

@ -118,18 +118,10 @@ func (sb *SymbolBuilder) Relocs() Relocs {
return sb.l.Relocs(sb.symIdx)
}
func (sb *SymbolBuilder) SetRelocs(rslice []Reloc) {
n := len(rslice)
if cap(sb.relocs) < n {
sb.relocs = make([]goobj2.Reloc, n)
sb.reltypes = make([]objabi.RelocType, n)
} else {
sb.relocs = sb.relocs[:n]
sb.reltypes = sb.reltypes[:n]
}
for i := range rslice {
sb.SetReloc(i, rslice[i])
}
// ResetRelocs removes all relocations on this symbol.
func (sb *SymbolBuilder) ResetRelocs() {
sb.relocs = sb.relocs[:0]
sb.reltypes = sb.reltypes[:0]
}
// SetRelocType sets the type of the 'i'-th relocation on this sym to 't'
@ -180,26 +172,6 @@ func (p *relocsByOff) Swap(i, j int) {
p.reltypes[i], p.reltypes[j] = p.reltypes[j], p.reltypes[i]
}
// AddReloc appends the specified reloc to the symbols list of
// relocations. Return value is the index of the newly created
// reloc.
func (sb *SymbolBuilder) AddReloc(r Reloc) uint32 {
// Populate a goobj2.Reloc from external reloc record.
rval := uint32(len(sb.relocs))
var b goobj2.Reloc
b.Set(r.Off, r.Size, 0, r.Add, goobj2.SymRef{PkgIdx: 0, SymIdx: uint32(r.Sym)})
sb.relocs = append(sb.relocs, b)
sb.reltypes = append(sb.reltypes, r.Type)
return rval
}
// Update the j-th relocation in place.
func (sb *SymbolBuilder) SetReloc(j int, r Reloc) {
// Populate a goobj2.Reloc from external reloc record.
sb.relocs[j].Set(r.Off, r.Size, 0, r.Add, goobj2.SymRef{PkgIdx: 0, SymIdx: uint32(r.Sym)})
sb.reltypes[j] = r.Type
}
func (sb *SymbolBuilder) Reachable() bool {
return sb.l.AttrReachable(sb.symIdx)
}
@ -323,14 +295,12 @@ func (sb *SymbolBuilder) SetAddrPlus(arch *sys.Arch, off int64, tgt Sym, add int
sb.size = off + int64(arch.PtrSize)
sb.Grow(sb.size)
}
var r Reloc
r.Sym = tgt
r.Off = int32(off)
r.Size = uint8(arch.PtrSize)
r.Type = objabi.R_ADDR
r.Add = add
sb.AddReloc(r)
return off + int64(r.Size)
r, _ := sb.AddRel(objabi.R_ADDR)
r.SetSym(tgt)
r.SetOff(int32(off))
r.SetSiz(uint8(arch.PtrSize))
r.SetAdd(add)
return off + int64(r.Siz())
}
func (sb *SymbolBuilder) SetAddr(arch *sys.Arch, off int64, tgt Sym) int64 {
@ -361,15 +331,13 @@ func (sb *SymbolBuilder) addSymRef(tgt Sym, add int64, typ objabi.RelocType, rsi
sb.size += int64(rsize)
sb.Grow(sb.size)
var r Reloc
r.Sym = tgt
r.Off = int32(i)
r.Size = uint8(rsize)
r.Type = typ
r.Add = add
sb.AddReloc(r)
r, _ := sb.AddRel(typ)
r.SetSym(tgt)
r.SetOff(int32(i))
r.SetSiz(uint8(rsize))
r.SetAdd(add)
return i + int64(r.Size)
return i + int64(rsize)
}
// Add a symbol reference (relocation) with given type, addend, and size

98
src/cmd/link/internal/ppc64/asm.go
View file

@ -152,13 +152,10 @@ func genaddmoduledata(ctxt *ld.Link, ldr *loader.Loader) {
// addis r2, r12, .TOC.-func@ha
toc := ctxt.DotTOC[0]
rel1 := loader.Reloc{
Off: 0,
Size: 8,
Type: objabi.R_ADDRPOWER_PCREL,
Sym: toc,
}
initfunc.AddReloc(rel1)
rel1, _ := initfunc.AddRel(objabi.R_ADDRPOWER_PCREL)
rel1.SetOff(0)
rel1.SetSiz(8)
rel1.SetSym(toc)
o(0x3c4c0000)
// addi r2, r2, .TOC.-func@l
o(0x38420000)
@ -175,24 +172,18 @@ func genaddmoduledata(ctxt *ld.Link, ldr *loader.Loader) {
} else {
tgt = ldr.LookupOrCreateSym("runtime.firstmoduledata", 0)
}
rel2 := loader.Reloc{
Off: int32(initfunc.Size()),
Size: 8,
Type: objabi.R_ADDRPOWER_GOT,
Sym: tgt,
}
initfunc.AddReloc(rel2)
rel2, _ := initfunc.AddRel(objabi.R_ADDRPOWER_GOT)
rel2.SetOff(int32(initfunc.Size()))
rel2.SetSiz(8)
rel2.SetSym(tgt)
o(0x3c620000)
// ld r3, local.moduledata@got@l(r3)
o(0xe8630000)
// bl runtime.addmoduledata
rel3 := loader.Reloc{
Off: int32(initfunc.Size()),
Size: 4,
Type: objabi.R_CALLPOWER,
Sym: addmoduledata,
}
initfunc.AddReloc(rel3)
rel3, _ := initfunc.AddRel(objabi.R_CALLPOWER)
rel3.SetOff(int32(initfunc.Size()))
rel3.SetSiz(4)
rel3.SetSym(addmoduledata)
o(0x48000001)
// nop
o(0x60000000)
@ -233,31 +224,25 @@ func gencallstub(ctxt *ld.Link, ldr *loader.Loader, abicase int, stub *loader.Sy
stub.AddUint32(ctxt.Arch, 0xf8410018) // std r2,24(r1)
// Load the function pointer from the PLT.
rel := loader.Reloc{
Off: int32(stub.Size()),
Size: 2,
Add: int64(ldr.SymPlt(targ)),
Type: objabi.R_POWER_TOC,
Sym: plt,
}
rel, ri1 := stub.AddRel(objabi.R_POWER_TOC)
rel.SetOff(int32(stub.Size()))
rel.SetSiz(2)
rel.SetAdd(int64(ldr.SymPlt(targ)))
rel.SetSym(plt)
if ctxt.Arch.ByteOrder == binary.BigEndian {
rel.Off += int32(rel.Size)
rel.SetOff(rel.Off() + int32(rel.Siz()))
}
ri1 := stub.AddReloc(rel)
ldr.SetRelocVariant(stub.Sym(), int(ri1), sym.RV_POWER_HA)
stub.AddUint32(ctxt.Arch, 0x3d820000) // addis r12,r2,targ@plt@toc@ha
rel2 := loader.Reloc{
Off: int32(stub.Size()),
Size: 2,
Add: int64(ldr.SymPlt(targ)),
Type: objabi.R_POWER_TOC,
Sym: plt,
}
rel2, ri2 := stub.AddRel(objabi.R_POWER_TOC)
rel2.SetOff(int32(stub.Size()))
rel2.SetSiz(2)
rel2.SetAdd(int64(ldr.SymPlt(targ)))
rel2.SetSym(plt)
if ctxt.Arch.ByteOrder == binary.BigEndian {
rel2.Off += int32(rel.Size)
rel2.SetOff(rel2.Off() + int32(rel2.Siz()))
}
ri2 := stub.AddReloc(rel2)
ldr.SetRelocVariant(stub.Sym(), int(ri2), sym.RV_POWER_LO)
stub.AddUint32(ctxt.Arch, 0xe98c0000) // ld r12,targ@plt@toc@l(r12)
@ -751,13 +736,10 @@ func gentramp(ctxt *ld.Link, ldr *loader.Loader, tramp *loader.SymbolBuilder, ta
toctramp.SetType(sym.SXCOFFTOC)
toctramp.AddAddrPlus(ctxt.Arch, target, offset)
r := loader.Reloc{
Off: 0,
Type: objabi.R_ADDRPOWER_TOCREL_DS,
Size: 8, // generates 2 relocations: HA + LO
Sym: toctramp.Sym(),
}
tramp.AddReloc(r)
r, _ := tramp.AddRel(objabi.R_ADDRPOWER_TOCREL_DS)
r.SetOff(0)
r.SetSiz(8) // generates 2 relocations: HA + LO
r.SetSym(toctramp.Sym())
} else {
// Used for default build mode for an executable
// Address of the call target is generated using
@ -768,14 +750,11 @@ func gentramp(ctxt *ld.Link, ldr *loader.Loader, tramp *loader.SymbolBuilder, ta
// With external linking, the target address must be
// relocated using LO and HA
if ctxt.IsExternal() {
r := loader.Reloc{
Off: 0,
Type: objabi.R_ADDRPOWER,
Size: 8, // generates 2 relocations: HA + LO
Sym: target,
Add: offset,
}
tramp.AddReloc(r)
r, _ := tramp.AddRel(objabi.R_ADDRPOWER)
r.SetOff(0)
r.SetSiz(8) // generates 2 relocations: HA + LO
r.SetSym(target)
r.SetAdd(offset)
} else {
// adjustment needed if lo has sign bit set
// when using addi to compute address
@ -1000,13 +979,10 @@ func addpltsym(ctxt *ld.Link, ldr *loader.Loader, s loader.Sym) {
// Write symbol resolver stub (just a branch to the
// glink resolver stub)
rel := loader.Reloc{
Off: int32(glink.Size()),
Size: 4,
Type: objabi.R_CALLPOWER,
Sym: glink.Sym(),
}
glink.AddReloc(rel)
rel, _ := glink.AddRel(objabi.R_CALLPOWER)
rel.SetOff(int32(glink.Size()))
rel.SetSiz(4)
rel.SetSym(glink.Sym())
glink.AddUint32(ctxt.Arch, 0x48000000) // b .glink
// In the ppc64 ABI, the dynamic linker is responsible