作者：hurkg
项目：g
func stacksplitPost(ctxt *obj.Link, p *obj.Prog, pPre *obj.Prog, pPreempt *obj.Prog) *obj.Prog {
// MOVD LR, R5
p = obj.Appendp(ctxt, p)
pPre.Pcond = p
p.As = AMOVD
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_LR
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R5
if pPreempt != nil {
pPreempt.Pcond = p
}
// BL runtime.morestack(SB)
p = obj.Appendp(ctxt, p)
p.As = ABL
p.To.Type = obj.TYPE_BRANCH
if ctxt.Cursym.Cfunc {
p.To.Sym = obj.Linklookup(ctxt, "runtime.morestackc", 0)
} else if ctxt.Cursym.Text.From3.Offset&obj.NEEDCTXT == 0 {
p.To.Sym = obj.Linklookup(ctxt, "runtime.morestack_noctxt", 0)
} else {
p.To.Sym = obj.Linklookup(ctxt, "runtime.morestack", 0)
}
// BR start
p = obj.Appendp(ctxt, p)
p.As = ABR
p.To.Type = obj.TYPE_BRANCH
p.Pcond = ctxt.Cursym.Text.Link
return p
}
作者：arnold
项目：g
func initdiv(ctxt *obj.Link) {
if ctxt.Sym_div != nil {
return
}
ctxt.Sym_div = obj.Linklookup(ctxt, "_div", 0)
ctxt.Sym_divu = obj.Linklookup(ctxt, "_divu", 0)
ctxt.Sym_mod = obj.Linklookup(ctxt, "_mod", 0)
ctxt.Sym_modu = obj.Linklookup(ctxt, "_modu", 0)
}
作者：kuangchanglan
项目：g
func stacksplitPost(ctxt *obj.Link, p *obj.Prog, pPre *obj.Prog, pPreempt *obj.Prog, framesize int32) *obj.Prog {
// Now we are at the end of the function, but logically
// we are still in function prologue. We need to fix the
// SP data and PCDATA.
spfix := obj.Appendp(ctxt, p)
spfix.As = obj.ANOP
spfix.Spadj = -framesize
pcdata := obj.Appendp(ctxt, spfix)
pcdata.Lineno = ctxt.Cursym.Text.Lineno
pcdata.Mode = ctxt.Cursym.Text.Mode
pcdata.As = obj.APCDATA
pcdata.From.Type = obj.TYPE_CONST
pcdata.From.Offset = obj.PCDATA_StackMapIndex
pcdata.To.Type = obj.TYPE_CONST
pcdata.To.Offset = -1 // pcdata starts at -1 at function entry
// MOVD LR, R5
p = obj.Appendp(ctxt, pcdata)
pPre.Pcond = p
p.As = AMOVD
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_LR
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R5
if pPreempt != nil {
pPreempt.Pcond = p
}
// BL runtime.morestack(SB)
p = obj.Appendp(ctxt, p)
p.As = ABL
p.To.Type = obj.TYPE_BRANCH
if ctxt.Cursym.Cfunc {
p.To.Sym = obj.Linklookup(ctxt, "runtime.morestackc", 0)
} else if ctxt.Cursym.Text.From3.Offset&obj.NEEDCTXT == 0 {
p.To.Sym = obj.Linklookup(ctxt, "runtime.morestack_noctxt", 0)
} else {
p.To.Sym = obj.Linklookup(ctxt, "runtime.morestack", 0)
}
// BR start
p = obj.Appendp(ctxt, p)
p.As = ABR
p.To.Type = obj.TYPE_BRANCH
p.Pcond = ctxt.Cursym.Text.Link
return p
}
作者：oshimay
项目：g
func stringsym(s string) (data *obj.LSym) {
var symname string
if len(s) > 100 {
// Huge strings are hashed to avoid long names in object files.
// Indulge in some paranoia by writing the length of s, too,
// as protection against length extension attacks.
h := sha256.New()
io.WriteString(h, s)
symname = fmt.Sprintf(".gostring.%d.%x", len(s), h.Sum(nil))
} else {
// Small strings get named directly by their contents.
symname = strconv.Quote(s)
}
const prefix = "go.string."
symdataname := prefix + symname
symdata := obj.Linklookup(Ctxt, symdataname, 0)
if !symdata.SeenGlobl() {
// string data
off := dsnameLSym(symdata, 0, s)
ggloblLSym(symdata, int32(off), obj.DUPOK|obj.RODATA|obj.LOCAL)
}
return symdata
}
作者：duhaibo040
项目：go-
func rewriteToPcrel(ctxt *obj.Link, p *obj.Prog) {
// RegTo2 is set on the instructions we insert here so they don't get
// processed twice.
if p.RegTo2 != 0 {
return
}
if p.As == obj.ATEXT || p.As == obj.AFUNCDATA || p.As == obj.ACALL || p.As == obj.ARET || p.As == obj.AJMP {
return
}
// Any Prog (aside from the above special cases) with an Addr with Name ==
// NAME_EXTERN, NAME_STATIC or NAME_GOTREF has a CALL __x86.get_pc_thunk.cx
// inserted before it.
isName := func(a *obj.Addr) bool {
if a.Sym == nil || (a.Type != obj.TYPE_MEM && a.Type != obj.TYPE_ADDR) || a.Reg != 0 {
return false
}
if a.Sym.Type == obj.STLSBSS {
return false
}
return a.Name == obj.NAME_EXTERN || a.Name == obj.NAME_STATIC || a.Name == obj.NAME_GOTREF
}
if isName(&p.From) && p.From.Type == obj.TYPE_ADDR {
// Handle things like "MOVL $sym, (SP)" or "PUSHL $sym" by rewriting
// to "MOVL $sym, CX; MOVL CX, (SP)" or "MOVL $sym, CX; PUSHL CX"
// respectively.
if p.To.Type != obj.TYPE_REG {
q := obj.Appendp(ctxt, p)
q.As = p.As
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_CX
q.To = p.To
p.As = AMOVL
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_CX
p.To.Sym = nil
p.To.Name = obj.NAME_NONE
}
}
if !isName(&p.From) && !isName(&p.To) && (p.From3 == nil || !isName(p.From3)) {
return
}
q := obj.Appendp(ctxt, p)
q.RegTo2 = 1
r := obj.Appendp(ctxt, q)
r.RegTo2 = 1
q.As = obj.ACALL
q.To.Sym = obj.Linklookup(ctxt, "__x86.get_pc_thunk.cx", 0)
q.To.Type = obj.TYPE_MEM
q.To.Name = obj.NAME_EXTERN
q.To.Sym.Local = true
r.As = p.As
r.Scond = p.Scond
r.From = p.From
r.From3 = p.From3
r.Reg = p.Reg
r.To = p.To
obj.Nopout(p)
}
作者：2theto
项目：g
func dimportpath(p *Pkg) {
if p.Pathsym != nil {
return
}
// If we are compiling the runtime package, there are two runtime packages around
// -- localpkg and Runtimepkg. We don't want to produce import path symbols for
// both of them, so just produce one for localpkg.
if myimportpath == "runtime" && p == Runtimepkg {
return
}
var str string
if p == localpkg {
// Note: myimportpath != "", or else dgopkgpath won't call dimportpath.
str = myimportpath
} else {
str = p.Path
}
s := obj.Linklookup(Ctxt, "type..importpath."+p.Prefix+".", 0)
ot := dnameData(s, 0, str, "", nil, false)
ggloblLSym(s, int32(ot), obj.DUPOK|obj.RODATA)
p.Pathsym = s
}
作者：2theto
项目：g
// dname creates a reflect.name for a struct field or method.
func dname(name, tag string, pkg *Pkg, exported bool) *obj.LSym {
// Write out data as "type.." to signal two things to the
// linker, first that when dynamically linking, the symbol
// should be moved to a relro section, and second that the
// contents should not be decoded as a type.
sname := "type..namedata."
if pkg == nil {
// In the common case, share data with other packages.
if name == "" {
if exported {
sname += "-noname-exported." + tag
} else {
sname += "-noname-unexported." + tag
}
} else {
sname += name + "." + tag
}
} else {
sname = fmt.Sprintf(`%s"".%d`, sname, dnameCount)
dnameCount++
}
s := obj.Linklookup(Ctxt, sname, 0)
if len(s.P) > 0 {
return s
}
ot := dnameData(s, 0, name, tag, pkg, exported)
ggloblLSym(s, int32(ot), obj.DUPOK|obj.RODATA)
return s
}
作者：duhaibo040
项目：go-
// dname dumps a reflect.name for a struct field or method.
func dname(s *Sym, ot int, name, tag string, pkg *Pkg, exported bool) int {
if len(name) > 1<<16-1 {
Fatalf("name too long: %s", name)
}
if len(tag) > 1<<16-1 {
Fatalf("tag too long: %s", tag)
}
// Encode name and tag. See reflect/type.go for details.
var bits byte
l := 1 + 2 + len(name)
if exported {
bits |= 1 << 0
}
if len(tag) > 0 {
l += 2 + len(tag)
bits |= 1 << 1
}
if pkg != nil {
bits |= 1 << 2
}
b := make([]byte, l)
b[0] = bits
b[1] = uint8(len(name) >> 8)
b[2] = uint8(len(name))
copy(b[3:], name)
if len(tag) > 0 {
tb := b[3+len(name):]
tb[0] = uint8(len(tag) >> 8)
tb[1] = uint8(len(tag))
copy(tb[2:], tag)
}
// Very few names require a pkgPath *string (only those
// defined in a different package than their type). So if
// there is no pkgPath, we treat the name contents as string
// data that duplicates across packages.
var bsym *obj.LSym
if pkg == nil {
_, bsym = stringsym(string(b))
} else {
// Write out data as "type.." to signal two things to the
// linker, first that when dynamically linking, the symbol
// should be moved to a relro section, and second that the
// contents should not be decoded as a type.
bsymname := fmt.Sprintf(`type..methodname."".%d`, dnameCount)
dnameCount++
bsym = obj.Linklookup(Ctxt, bsymname, 0)
bsym.P = b
boff := len(b)
boff = int(Rnd(int64(boff), int64(Widthptr)))
boff = dgopkgpathLSym(bsym, boff, pkg)
ggloblLSym(bsym, int32(boff), obj.RODATA|obj.LOCAL)
}
ot = dsymptrLSym(Linksym(s), ot, bsym, 0)
return ot
}
作者：kuangchanglan
项目：g
func stringsym(s string) (hdr, data *obj.LSym) {
var symname string
if len(s) > 100 {
// Huge strings are hashed to avoid long names in object files.
// Indulge in some paranoia by writing the length of s, too,
// as protection against length extension attacks.
h := sha256.New()
io.WriteString(h, s)
symname = fmt.Sprintf(".gostring.%d.%x", len(s), h.Sum(nil))
} else {
// Small strings get named directly by their contents.
symname = strconv.Quote(s)
}
const prefix = "go.string."
symdataname := prefix + symname
// All the strings have the same prefix, so ignore it for map
// purposes, but use a slice of the symbol name string to
// reduce long-term memory overhead.
key := symdataname[len(prefix):]
if syms, ok := stringConstants[key]; ok {
return syms.hdr, syms.data
}
symhdrname := "go.string.hdr." + symname
symhdr := obj.Linklookup(Ctxt, symhdrname, 0)
symdata := obj.Linklookup(Ctxt, symdataname, 0)
stringConstants[key] = stringConstantSyms{symhdr, symdata}
// string header
off := 0
off = dsymptrLSym(symhdr, off, symdata, 0)
off = duintxxLSym(symhdr, off, uint64(len(s)), Widthint)
ggloblLSym(symhdr, int32(off), obj.DUPOK|obj.RODATA|obj.LOCAL)
// string data
off = dsnameLSym(symdata, 0, s)
ggloblLSym(symdata, int32(off), obj.DUPOK|obj.RODATA|obj.LOCAL)
return symhdr, symdata
}
作者：2theto
项目：g
// dgopkgpathOffLSym writes an offset relocation in s at offset ot to the pkg path symbol.
func dgopkgpathOffLSym(s *obj.LSym, ot int, pkg *Pkg) int {
if pkg == nil {
return duintxxLSym(s, ot, 0, 4)
}
if pkg == localpkg && myimportpath == "" {
// If we don't know the full import path of the package being compiled
// (i.e. -p was not passed on the compiler command line), emit a reference to
// type..importpath.""., which the linker will rewrite using the correct import path.
// Every package that imports this one directly defines the symbol.
// See also https://groups.google.com/forum/#!topic/golang-dev/myb9s53HxGQ.
ns := obj.Linklookup(Ctxt, `type..importpath."".`, 0)
return dsymptrOffLSym(s, ot, ns, 0)
}
dimportpath(pkg)
return dsymptrOffLSym(s, ot, pkg.Pathsym, 0)
}
作者：ronaldsl
项目：g
func Linksym(s *Sym) *obj.LSym {
if s == nil {
return nil
}
if s.Lsym != nil {
return s.Lsym
}
var name string
if isblanksym(s) {
name = "_"
} else if s.Linkname != "" {
name = s.Linkname
} else {
name = s.Pkg.Prefix + "." + s.Name
}
ls := obj.Linklookup(Ctxt, name, 0)
s.Lsym = ls
return ls
}
作者：achand
项目：g
//.........这里部分代码省略.........
}
}
order(Curfn)
if nerrors != 0 {
return
}
hasdefer = false
walk(Curfn)
if nerrors != 0 {
return
}
if instrumenting {
instrument(Curfn)
}
if nerrors != 0 {
return
}
// Build an SSA backend function.
ssafn := buildssa(Curfn)
if nerrors != 0 {
return
}
newplist()
setlineno(Curfn)
nam := Curfn.Func.Nname
if isblank(nam) {
nam = nil
}
ptxt := Gins(obj.ATEXT, nam, nil)
ptxt.From3 = new(obj.Addr)
if fn.Func.Dupok {
ptxt.From3.Offset |= obj.DUPOK
}
if fn.Func.Wrapper {
ptxt.From3.Offset |= obj.WRAPPER
}
if fn.Func.Needctxt {
ptxt.From3.Offset |= obj.NEEDCTXT
}
if fn.Func.Pragma&Nosplit != 0 {
ptxt.From3.Offset |= obj.NOSPLIT
}
if fn.Func.ReflectMethod {
ptxt.From3.Offset |= obj.REFLECTMETHOD
}
if fn.Func.Pragma&Systemstack != 0 {
ptxt.From.Sym.Set(obj.AttrCFunc, true)
}
// Clumsy but important.
// See test/recover.go for test cases and src/reflect/value.go
// for the actual functions being considered.
if myimportpath == "reflect" {
if Curfn.Func.Nname.Sym.Name == "callReflect" || Curfn.Func.Nname.Sym.Name == "callMethod" {
ptxt.From3.Offset |= obj.WRAPPER
}
}
gcargs := makefuncdatasym("gcargs·", obj.FUNCDATA_ArgsPointerMaps)
gclocals := makefuncdatasym("gclocals·", obj.FUNCDATA_LocalsPointerMaps)
if obj.Fieldtrack_enabled != 0 && len(Curfn.Func.FieldTrack) > 0 {
trackSyms := make([]*Sym, 0, len(Curfn.Func.FieldTrack))
for sym := range Curfn.Func.FieldTrack {
trackSyms = append(trackSyms, sym)
}
sort.Sort(symByName(trackSyms))
for _, sym := range trackSyms {
gtrack(sym)
}
}
for _, n := range fn.Func.Dcl {
if n.Op != ONAME { // might be OTYPE or OLITERAL
continue
}
switch n.Class {
case PAUTO:
if !n.Used {
continue
}
fallthrough
case PPARAM, PPARAMOUT:
p := Gins(obj.ATYPE, n, nil)
p.From.Sym = obj.Linklookup(Ctxt, n.Sym.Name, 0)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = Linksym(ngotype(n))
}
}
genssa(ssafn, ptxt, gcargs, gclocals)
ssafn.Free()
}
作者：Ericea
项目：g
//.........这里部分代码省略.........
case 104:
yyDollar = yyS[yypt-1 : yypt+1]
//line a.y:665
{
yyVAL.addr = nullgen
yyVAL.addr.Type = obj.TYPE_REG
yyVAL.addr.Reg = int16(yyDollar[1].lval)
}
case 105:
yyDollar = yyS[yypt-4 : yypt+1]
//line a.y:671
{
yyVAL.addr = nullgen
yyVAL.addr.Type = obj.TYPE_REG
yyVAL.addr.Reg = int16(REG_F0 + yyDollar[3].lval)
}
case 106:
yyDollar = yyS[yypt-4 : yypt+1]
//line a.y:679
{
yyVAL.addr = nullgen
yyVAL.addr.Type = obj.TYPE_MEM
yyVAL.addr.Name = int8(yyDollar[3].lval)
yyVAL.addr.Sym = nil
yyVAL.addr.Offset = int64(yyDollar[1].lval)
}
case 107:
yyDollar = yyS[yypt-5 : yypt+1]
//line a.y:687
{
yyVAL.addr = nullgen
yyVAL.addr.Type = obj.TYPE_MEM
yyVAL.addr.Name = int8(yyDollar[4].lval)
yyVAL.addr.Sym = obj.Linklookup(asm.Ctxt, yyDollar[1].sym.Name, 0)
yyVAL.addr.Offset = int64(yyDollar[2].lval)
}
case 108:
yyDollar = yyS[yypt-7 : yypt+1]
//line a.y:695
{
yyVAL.addr = nullgen
yyVAL.addr.Type = obj.TYPE_MEM
yyVAL.addr.Name = obj.NAME_STATIC
yyVAL.addr.Sym = obj.Linklookup(asm.Ctxt, yyDollar[1].sym.Name, 1)
yyVAL.addr.Offset = int64(yyDollar[4].lval)
}
case 109:
yyDollar = yyS[yypt-0 : yypt+1]
//line a.y:704
{
yyVAL.lval = 0
}
case 110:
yyDollar = yyS[yypt-2 : yypt+1]
//line a.y:708
{
yyVAL.lval = yyDollar[2].lval
}
case 111:
yyDollar = yyS[yypt-2 : yypt+1]
//line a.y:712
{
yyVAL.lval = -yyDollar[2].lval
}
case 116:
yyDollar = yyS[yypt-1 : yypt+1]
作者：oshimay
项目：g
func dumptypestructs() {
// copy types from externdcl list to signatlist
for _, n := range externdcl {
if n.Op != OTYPE {
continue
}
signatlist = append(signatlist, n)
}
// Process signatlist. This can't use range, as entries are
// added to the list while it is being processed.
for i := 0; i < len(signatlist); i++ {
n := signatlist[i]
if n.Op != OTYPE {
continue
}
t := n.Type
dtypesym(t)
if t.Sym != nil {
dtypesym(ptrto(t))
}
}
// process itabs
for _, i := range itabs {
// dump empty itab symbol into i.sym
// type itab struct {
// inter *interfacetype
// _type *_type
// link *itab
// bad int32
// unused int32
// fun [1]uintptr // variable sized
// }
o := dsymptr(i.sym, 0, dtypesym(i.itype), 0)
o = dsymptr(i.sym, o, dtypesym(i.t), 0)
o += Widthptr + 8 // skip link/bad/unused fields
o += len(imethods(i.itype)) * Widthptr // skip fun method pointers
// at runtime the itab will contain pointers to types, other itabs and
// method functions. None are allocated on heap, so we can use obj.NOPTR.
ggloblsym(i.sym, int32(o), int16(obj.DUPOK|obj.NOPTR|obj.LOCAL))
ilink := Pkglookup(i.t.tconv(FmtLeft)+","+i.itype.tconv(FmtLeft), itablinkpkg)
dsymptr(ilink, 0, i.sym, 0)
ggloblsym(ilink, int32(Widthptr), int16(obj.DUPOK|obj.RODATA|obj.LOCAL))
}
// process ptabs
if localpkg.Name == "main" && len(ptabs) > 0 {
ot := 0
s := obj.Linklookup(Ctxt, "go.plugin.tabs", 0)
for _, p := range ptabs {
// Dump ptab symbol into go.pluginsym package.
//
// type ptab struct {
// name nameOff
// typ typeOff // pointer to symbol
// }
nsym := dname(p.s.Name, "", nil, true)
ot = dsymptrOffLSym(s, ot, nsym, 0)
ot = dsymptrOffLSym(s, ot, Linksym(dtypesym(p.t)), 0)
}
ggloblLSym(s, int32(ot), int16(obj.RODATA))
ot = 0
s = obj.Linklookup(Ctxt, "go.plugin.exports", 0)
for _, p := range ptabs {
ot = dsymptrLSym(s, ot, Linksym(p.s), 0)
}
ggloblLSym(s, int32(ot), int16(obj.RODATA))
}
// generate import strings for imported packages
if forceObjFileStability {
// Sorting the packages is not necessary but to compare binaries created
// using textual and binary format we sort by path to reduce differences.
sort.Sort(pkgByPath(pkgs))
}
for _, p := range pkgs {
if p.Direct {
dimportpath(p)
}
}
// do basic types if compiling package runtime.
// they have to be in at least one package,
// and runtime is always loaded implicitly,
// so this is as good as any.
// another possible choice would be package main,
// but using runtime means fewer copies in .6 files.
if myimportpath == "runtime" {
for i := EType(1); i <= TBOOL; i++ {
dtypesym(ptrto(Types[i]))
}
dtypesym(ptrto(Types[TSTRING]))
dtypesym(ptrto(Types[TUNSAFEPTR]))
// emit type structs for error and func(error) string.
// The latter is the type of an auto-generated wrapper.
dtypesym(ptrto(errortype))
//.........这里部分代码省略.........
作者：duhaibo040
项目：go-
func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
if ctxt.Headtype == obj.Hplan9 && ctxt.Plan9privates == nil {
ctxt.Plan9privates = obj.Linklookup(ctxt, "_privates", 0)
}
ctxt.Cursym = cursym
if cursym.Text == nil || cursym.Text.Link == nil {
return
}
p := cursym.Text
autoffset := int32(p.To.Offset)
if autoffset < 0 {
autoffset = 0
}
var bpsize int
if p.Mode == 64 && obj.Framepointer_enabled != 0 && autoffset > 0 {
// Make room for to save a base pointer. If autoffset == 0,
// this might do something special like a tail jump to
// another function, so in that case we omit this.
bpsize = ctxt.Arch.Ptrsize
autoffset += int32(bpsize)
p.To.Offset += int64(bpsize)
} else {
bpsize = 0
}
textarg := int64(p.To.Val.(int32))
cursym.Args = int32(textarg)
cursym.Locals = int32(p.To.Offset)
// TODO(rsc): Remove.
if p.Mode == 32 && cursym.Locals < 0 {
cursym.Locals = 0
}
// TODO(rsc): Remove 'p.Mode == 64 &&'.
if p.Mode == 64 && autoffset < obj.StackSmall && p.From3Offset()&obj.NOSPLIT == 0 {
for q := p; q != nil; q = q.Link {
if q.As == obj.ACALL {
goto noleaf
}
if (q.As == obj.ADUFFCOPY || q.As == obj.ADUFFZERO) && autoffset >= obj.StackSmall-8 {
goto noleaf
}
}
p.From3.Offset |= obj.NOSPLIT
noleaf:
}
if p.From3Offset()&obj.NOSPLIT == 0 || p.From3Offset()&obj.WRAPPER != 0 {
p = obj.Appendp(ctxt, p)
p = load_g_cx(ctxt, p) // load g into CX
}
if cursym.Text.From3Offset()&obj.NOSPLIT == 0 {
p = stacksplit(ctxt, p, autoffset, int32(textarg)) // emit split check
}
if autoffset != 0 {
if autoffset%int32(ctxt.Arch.Regsize) != 0 {
ctxt.Diag("unaligned stack size %d", autoffset)
}
p = obj.Appendp(ctxt, p)
p.As = AADJSP
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(autoffset)
p.Spadj = autoffset
} else {
// zero-byte stack adjustment.
// Insert a fake non-zero adjustment so that stkcheck can
// recognize the end of the stack-splitting prolog.
p = obj.Appendp(ctxt, p)
p.As = obj.ANOP
p.Spadj = int32(-ctxt.Arch.Ptrsize)
p = obj.Appendp(ctxt, p)
p.As = obj.ANOP
p.Spadj = int32(ctxt.Arch.Ptrsize)
}
deltasp := autoffset
if bpsize > 0 {
// Save caller's BP
p = obj.Appendp(ctxt, p)
p.As = AMOVQ
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_BP
p.To.Type = obj.TYPE_MEM
p.To.Reg = REG_SP
p.To.Scale = 1
p.To.Offset = int64(autoffset) - int64(bpsize)
// Move current frame to BP
//.........这里部分代码省略.........
作者：duhaibo040
项目：go-
//.........这里部分代码省略.........
if ctxt.Headtype == obj.Hnacl && p.Mode == 64 {
if p.From3 != nil {
nacladdr(ctxt, p, p.From3)
}
nacladdr(ctxt, p, &p.From)
nacladdr(ctxt, p, &p.To)
}
// Rewrite float constants to values stored in memory.
switch p.As {
// Convert AMOVSS $(0), Xx to AXORPS Xx, Xx
case AMOVSS:
if p.From.Type == obj.TYPE_FCONST {
// f == 0 can't be used here due to -0, so use Float64bits
if f := p.From.Val.(float64); math.Float64bits(f) == 0 {
if p.To.Type == obj.TYPE_REG && REG_X0 <= p.To.Reg && p.To.Reg <= REG_X15 {
p.As = AXORPS
p.From = p.To
break
}
}
}
fallthrough
case AFMOVF,
AFADDF,
AFSUBF,
AFSUBRF,
AFMULF,
AFDIVF,
AFDIVRF,
AFCOMF,
AFCOMFP,
AADDSS,
ASUBSS,
AMULSS,
ADIVSS,
ACOMISS,
AUCOMISS:
if p.From.Type == obj.TYPE_FCONST {
f32 := float32(p.From.Val.(float64))
i32 := math.Float32bits(f32)
literal := fmt.Sprintf("$f32.%08x", i32)
s := obj.Linklookup(ctxt, literal, 0)
p.From.Type = obj.TYPE_MEM
p.From.Name = obj.NAME_EXTERN
p.From.Sym = s
p.From.Sym.Local = true
p.From.Offset = 0
}
case AMOVSD:
// Convert AMOVSD $(0), Xx to AXORPS Xx, Xx
if p.From.Type == obj.TYPE_FCONST {
// f == 0 can't be used here due to -0, so use Float64bits
if f := p.From.Val.(float64); math.Float64bits(f) == 0 {
if p.To.Type == obj.TYPE_REG && REG_X0 <= p.To.Reg && p.To.Reg <= REG_X15 {
p.As = AXORPS
p.From = p.To
break
}
}
}
fallthrough
case AFMOVD,
AFADDD,
AFSUBD,
AFSUBRD,
AFMULD,
AFDIVD,
AFDIVRD,
AFCOMD,
AFCOMDP,
AADDSD,
ASUBSD,
AMULSD,
ADIVSD,
ACOMISD,
AUCOMISD:
if p.From.Type == obj.TYPE_FCONST {
i64 := math.Float64bits(p.From.Val.(float64))
literal := fmt.Sprintf("$f64.%016x", i64)
s := obj.Linklookup(ctxt, literal, 0)
p.From.Type = obj.TYPE_MEM
p.From.Name = obj.NAME_EXTERN
p.From.Sym = s
p.From.Sym.Local = true
p.From.Offset = 0
}
}
if ctxt.Flag_dynlink {
rewriteToUseGot(ctxt, p)
}
if ctxt.Flag_shared != 0 && p.Mode == 32 {
rewriteToPcrel(ctxt, p)
}
}
作者：duhaibo040
项目：go-
// Rewrite p, if necessary, to access global data via the global offset table.
func rewriteToUseGot(ctxt *obj.Link, p *obj.Prog) {
var add, lea, mov obj.As
var reg int16
if p.Mode == 64 {
add = AADDQ
lea = ALEAQ
mov = AMOVQ
reg = REG_R15
} else {
add = AADDL
lea = ALEAL
mov = AMOVL
reg = REG_CX
}
if p.As == obj.ADUFFCOPY || p.As == obj.ADUFFZERO {
// ADUFFxxx $offset
// becomes
// $MOV [email protected], $reg
// $ADD $offset, $reg
// CALL $reg
var sym *obj.LSym
if p.As == obj.ADUFFZERO {
sym = obj.Linklookup(ctxt, "runtime.duffzero", 0)
} else {
sym = obj.Linklookup(ctxt, "runtime.duffcopy", 0)
}
offset := p.To.Offset
p.As = mov
p.From.Type = obj.TYPE_MEM
p.From.Name = obj.NAME_GOTREF
p.From.Sym = sym
p.To.Type = obj.TYPE_REG
p.To.Reg = reg
p.To.Offset = 0
p.To.Sym = nil
p1 := obj.Appendp(ctxt, p)
p1.As = add
p1.From.Type = obj.TYPE_CONST
p1.From.Offset = offset
p1.To.Type = obj.TYPE_REG
p1.To.Reg = reg
p2 := obj.Appendp(ctxt, p1)
p2.As = obj.ACALL
p2.To.Type = obj.TYPE_REG
p2.To.Reg = reg
}
// We only care about global data: NAME_EXTERN means a global
// symbol in the Go sense, and p.Sym.Local is true for a few
// internally defined symbols.
if p.As == lea && p.From.Type == obj.TYPE_MEM && p.From.Name == obj.NAME_EXTERN && !p.From.Sym.Local {
// $LEA sym, Rx becomes $MOV $sym, Rx which will be rewritten below
p.As = mov
p.From.Type = obj.TYPE_ADDR
}
if p.From.Type == obj.TYPE_ADDR && p.From.Name == obj.NAME_EXTERN && !p.From.Sym.Local {
// $MOV $sym, Rx becomes $MOV [email protected], Rx
// $MOV $sym+<off>, Rx becomes $MOV [email protected], Rx; $LEA <off>(Rx), Rx
// On 386 only, more complicated things like PUSHL $sym become $MOV [email protected], CX; PUSHL CX
cmplxdest := false
pAs := p.As
var dest obj.Addr
if p.To.Type != obj.TYPE_REG || pAs != mov {
if p.Mode == 64 {
ctxt.Diag("do not know how to handle LEA-type insn to non-register in %v with -dynlink", p)
}
cmplxdest = true
dest = p.To
p.As = mov
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_CX
p.To.Sym = nil
p.To.Name = obj.NAME_NONE
}
p.From.Type = obj.TYPE_MEM
p.From.Name = obj.NAME_GOTREF
q := p
if p.From.Offset != 0 {
q = obj.Appendp(ctxt, p)
q.As = lea
q.From.Type = obj.TYPE_MEM
q.From.Reg = p.To.Reg
q.From.Offset = p.From.Offset
q.To = p.To
p.From.Offset = 0
}
if cmplxdest {
q = obj.Appendp(ctxt, q)
q.As = pAs
q.To = dest
q.From.Type = obj.TYPE_REG
q.From.Reg = REG_CX
}
}
if p.From3 != nil && p.From3.Name == obj.NAME_EXTERN {
ctxt.Diag("don't know how to handle %v with -dynlink", p)
}
var source *obj.Addr
//.........这里部分代码省略.........
作者：gmw
项目：g
//.........这里部分代码省略.........
p.From.Offset = int64(framesize) + obj.StackGuard - obj.StackSmall
p.To.Type = obj.TYPE_REG
p.To.Reg = REGTMP
p = obj.Appendp(ctxt, p)
p.As = ACMPU
p.From.Type = obj.TYPE_REG
p.From.Reg = REGTMP
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R4
}
// q1: BLT done
p = obj.Appendp(ctxt, p)
q1 := p
p.As = ABLT
p.To.Type = obj.TYPE_BRANCH
// MOVD LR, R5
p = obj.Appendp(ctxt, p)
p.As = AMOVD
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_LR
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R5
if q != nil {
q.Pcond = p
}
var morestacksym *obj.LSym
if ctxt.Cursym.Cfunc != 0 {
morestacksym = obj.Linklookup(ctxt, "runtime.morestackc", 0)
} else if ctxt.Cursym.Text.From3.Offset&obj.NEEDCTXT == 0 {
morestacksym = obj.Linklookup(ctxt, "runtime.morestack_noctxt", 0)
} else {
morestacksym = obj.Linklookup(ctxt, "runtime.morestack", 0)
}
if ctxt.Flag_dynlink {
// Avoid calling morestack via a PLT when dynamically linking. The
// PLT stubs generated by the system linker on ppc64le when "std r2,
// 24(r1)" to save the TOC pointer in their callers stack
// frame. Unfortunately (and necessarily) morestack is called before
// the function that calls it sets up its frame and so the PLT ends
// up smashing the saved TOC pointer for its caller's caller.
//
// According to the ABI documentation there is a mechanism to avoid
// the TOC save that the PLT stub does (put a R_PPC64_TOCSAVE
// relocation on the nop after the call to morestack) but at the time
// of writing it is not supported at all by gold and my attempt to
// use it with ld.bfd caused an internal linker error. So this hack
// seems preferable.
// MOVD $runtime.morestack(SB), R12
p = obj.Appendp(ctxt, p)
p.As = AMOVD
p.From.Type = obj.TYPE_MEM
p.From.Sym = morestacksym
p.From.Name = obj.NAME_GOTREF
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R12
// MOVD R12, CTR
p = obj.Appendp(ctxt, p)
作者：arnold
项目：g
//.........这里部分代码省略.........
p.From.Offset = int64(-framesize)
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p = obj.Appendp(ctxt, p)
p.As = ACMP
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R1
p.Reg = REG_R2
} else {
// Such a large stack we need to protect against wraparound
// if SP is close to zero.
// SP-stackguard+StackGuard < framesize + (StackGuard-StackSmall)
// The +StackGuard on both sides is required to keep the left side positive:
// SP is allowed to be slightly below stackguard. See stack.h.
// CMP $StackPreempt, R1
// MOVW.NE $StackGuard(SP), R2
// SUB.NE R1, R2
// MOVW.NE $(framesize+(StackGuard-StackSmall)), R3
// CMP.NE R3, R2
p = obj.Appendp(ctxt, p)
p.As = ACMP
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(uint32(obj.StackPreempt & (1<<32 - 1)))
p.Reg = REG_R1
p = obj.Appendp(ctxt, p)
p.As = AMOVW
p.From.Type = obj.TYPE_ADDR
p.From.Reg = REGSP
p.From.Offset = obj.StackGuard
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p.Scond = C_SCOND_NE
p = obj.Appendp(ctxt, p)
p.As = ASUB
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R1
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p.Scond = C_SCOND_NE
p = obj.Appendp(ctxt, p)
p.As = AMOVW
p.From.Type = obj.TYPE_ADDR
p.From.Offset = int64(framesize) + (obj.StackGuard - obj.StackSmall)
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R3
p.Scond = C_SCOND_NE
p = obj.Appendp(ctxt, p)
p.As = ACMP
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R3
p.Reg = REG_R2
p.Scond = C_SCOND_NE
}
// BLS call-to-morestack
bls := obj.Appendp(ctxt, p)
bls.As = ABLS
bls.To.Type = obj.TYPE_BRANCH
var last *obj.Prog
for last = ctxt.Cursym.Text; last.Link != nil; last = last.Link {
}
// MOVW LR, R3
movw := obj.Appendp(ctxt, last)
movw.As = AMOVW
movw.From.Type = obj.TYPE_REG
movw.From.Reg = REGLINK
movw.To.Type = obj.TYPE_REG
movw.To.Reg = REG_R3
bls.Pcond = movw
// BL runtime.morestack
call := obj.Appendp(ctxt, movw)
call.As = obj.ACALL
call.To.Type = obj.TYPE_BRANCH
morestack := "runtime.morestack"
switch {
case ctxt.Cursym.Cfunc != 0:
morestack = "runtime.morestackc"
case ctxt.Cursym.Text.From3.Offset&obj.NEEDCTXT == 0:
morestack = "runtime.morestack_noctxt"
}
call.To.Sym = obj.Linklookup(ctxt, morestack, 0)
// B start
b := obj.Appendp(ctxt, call)
b.As = obj.AJMP
b.To.Type = obj.TYPE_BRANCH
b.Pcond = ctxt.Cursym.Text.Link
return bls
}
作者：hurkg
项目：g
//.........这里部分代码省略.........
p.As = ACMP
p.From.Type = obj.TYPE_CONST
p.From.Offset = obj.StackPreempt
p.Reg = REG_R1
p = obj.Appendp(ctxt, p)
q = p
p.As = ABEQ
p.To.Type = obj.TYPE_BRANCH
p = obj.Appendp(ctxt, p)
p.As = AADD
p.From.Type = obj.TYPE_CONST
p.From.Offset = obj.StackGuard
p.Reg = REGSP
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p = obj.Appendp(ctxt, p)
p.As = ASUB
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R1
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R2
p = obj.Appendp(ctxt, p)
p.As = AMOVD
p.From.Type = obj.TYPE_CONST
p.From.Offset = int64(framesize) + (obj.StackGuard - obj.StackSmall)
p.To.Type = obj.TYPE_REG
p.To.Reg = REG_R3
p = obj.Appendp(ctxt, p)
p.As = ACMP
p.From.Type = obj.TYPE_REG
p.From.Reg = REG_R3
p.Reg = REG_R2
}
// BLS do-morestack
bls := obj.Appendp(ctxt, p)
bls.As = ABLS
bls.To.Type = obj.TYPE_BRANCH
var last *obj.Prog
for last = ctxt.Cursym.Text; last.Link != nil; last = last.Link {
}
spfix := obj.Appendp(ctxt, last)
spfix.As = obj.ANOP
spfix.Spadj = -framesize
// MOV LR, R3
movlr := obj.Appendp(ctxt, spfix)
movlr.As = AMOVD
movlr.From.Type = obj.TYPE_REG
movlr.From.Reg = REGLINK
movlr.To.Type = obj.TYPE_REG
movlr.To.Reg = REG_R3
if q != nil {
q.Pcond = movlr
}
bls.Pcond = movlr
debug := movlr
if false {
debug = obj.Appendp(ctxt, debug)
debug.As = AMOVD
debug.From.Type = obj.TYPE_CONST
debug.From.Offset = int64(framesize)
debug.To.Type = obj.TYPE_REG
debug.To.Reg = REGTMP
}
// BL runtime.morestack(SB)
call := obj.Appendp(ctxt, debug)
call.As = ABL
call.To.Type = obj.TYPE_BRANCH
morestack := "runtime.morestack"
switch {
case ctxt.Cursym.Cfunc:
morestack = "runtime.morestackc"
case ctxt.Cursym.Text.From3.Offset&obj.NEEDCTXT == 0:
morestack = "runtime.morestack_noctxt"
}
call.To.Sym = obj.Linklookup(ctxt, morestack, 0)
// B start
jmp := obj.Appendp(ctxt, call)
jmp.As = AB
jmp.To.Type = obj.TYPE_BRANCH
jmp.Pcond = ctxt.Cursym.Text.Link
jmp.Spadj = +framesize
// placeholder for bls's jump target
// p = obj.Appendp(ctxt, p)
// p.As = obj.ANOP
return bls
}
