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// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package obj
import (
"fmt"
"log"
"strings"
)
type Plist struct {
Firstpc *Prog
}
/*
* start a new Prog list.
*/
func Linknewplist(ctxt *Link) *Plist {
pl := new(Plist)
ctxt.Plists = append(ctxt.Plists, pl)
return pl
}
func Flushplist(ctxt *Link) {
flushplist(ctxt, ctxt.Debugasm == 0)
}
func FlushplistNoFree(ctxt *Link) {
flushplist(ctxt, false)
}
func flushplist(ctxt *Link, freeProgs bool) {
// Build list of symbols, and assign instructions to lists.
// Ignore ctxt->plist boundaries. There are no guarantees there,
// and the assemblers just use one big list.
var curtext *LSym
var etext *Prog
var text []*LSym
for _, pl := range ctxt.Plists {
var plink *Prog
for p := pl.Firstpc; p != nil; p = plink {
if ctxt.Debugasm != 0 && ctxt.Debugvlog != 0 {
fmt.Printf("obj: %v\n", p)
}
plink = p.Link
p.Link = nil
switch p.As {
case AEND:
continue
case ATYPE:
// Assume each TYPE instruction describes
// a different local variable or parameter,
// so no dedup.
// Using only the TYPE instructions means
// that we discard location information about local variables
// in C and assembly functions; that information is inferred
// from ordinary references, because there are no TYPE
// instructions there. Without the type information, gdb can't
// use the locations, so we don't bother to save them.
// If something else could use them, we could arrange to
// preserve them.
if curtext == nil {
continue
}
a := new(Auto)
a.Asym = p.From.Sym
a.Aoffset = int32(p.From.Offset)
a.Name = int16(p.From.Name)
a.Gotype = p.To.Sym
a.Link = curtext.Autom
curtext.Autom = a
continue
case ATEXT:
s := p.From.Sym
if s == nil {
// func _() { }
curtext = nil
continue
}
if s.Text != nil {
log.Fatalf("duplicate TEXT for %s", s.Name)
}
if s.OnList() {
log.Fatalf("symbol %s listed multiple times", s.Name)
}
s.Set(AttrOnList, true)
text = append(text, s)
flag := int(p.From3Offset())
if flag&DUPOK != 0 {
s.Set(AttrDuplicateOK, true)
}
if flag&NOSPLIT != 0 {
s.Set(AttrNoSplit, true)
}
if flag&REFLECTMETHOD != 0 {
s.Set(AttrReflectMethod, true)
}
s.Type = STEXT
s.Text = p
etext = p
curtext = s
continue
case AFUNCDATA:
// Rewrite reference to go_args_stackmap(SB) to the Go-provided declaration information.
if curtext == nil { // func _() {}
continue
}
if p.To.Sym.Name == "go_args_stackmap" {
if p.From.Type != TYPE_CONST || p.From.Offset != FUNCDATA_ArgsPointerMaps {
ctxt.Diag("FUNCDATA use of go_args_stackmap(SB) without FUNCDATA_ArgsPointerMaps")
}
p.To.Sym = Linklookup(ctxt, fmt.Sprintf("%s.args_stackmap", curtext.Name), int(curtext.Version))
}
}
if curtext == nil {
etext = nil
continue
}
etext.Link = p
etext = p
}
}
// Add reference to Go arguments for C or assembly functions without them.
for _, s := range text {
if !strings.HasPrefix(s.Name, "\"\".") {
continue
}
found := false
var p *Prog
for p = s.Text; p != nil; p = p.Link {
if p.As == AFUNCDATA && p.From.Type == TYPE_CONST && p.From.Offset == FUNCDATA_ArgsPointerMaps {
found = true
break
}
}
if !found {
p = Appendp(ctxt, s.Text)
p.As = AFUNCDATA
p.From.Type = TYPE_CONST
p.From.Offset = FUNCDATA_ArgsPointerMaps
p.To.Type = TYPE_MEM
p.To.Name = NAME_EXTERN
p.To.Sym = Linklookup(ctxt, fmt.Sprintf("%s.args_stackmap", s.Name), int(s.Version))
}
}
// Turn functions into machine code images.
for _, s := range text {
mkfwd(s)
linkpatch(ctxt, s)
if ctxt.Flag_optimize {
ctxt.Arch.Follow(ctxt, s)
}
ctxt.Arch.Preprocess(ctxt, s)
ctxt.Arch.Assemble(ctxt, s)
fieldtrack(ctxt, s)
linkpcln(ctxt, s)
if freeProgs {
s.Text = nil
}
}
// Add to running list in ctxt.
ctxt.Text = append(ctxt.Text, text...)
ctxt.Data = append(ctxt.Data, gendwarf(ctxt, text)...)
ctxt.Plists = nil
ctxt.Curp = nil
if freeProgs {
ctxt.freeProgs()
}
}
func (ctxt *Link) Globl(s *LSym, size int64, flag int) {
if s.SeenGlobl() {
fmt.Printf("duplicate %v\n", s)
}
s.Set(AttrSeenGlobl, true)
if s.OnList() {
log.Fatalf("symbol %s listed multiple times", s.Name)
}
s.Set(AttrOnList, true)
ctxt.Data = append(ctxt.Data, s)
s.Size = size
if s.Type == 0 || s.Type == SXREF {
s.Type = SBSS
}
if flag&DUPOK != 0 {
s.Set(AttrDuplicateOK, true)
}
if flag&RODATA != 0 {
s.Type = SRODATA
} else if flag&NOPTR != 0 {
s.Type = SNOPTRBSS
} else if flag&TLSBSS != 0 {
s.Type = STLSBSS
}
}
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