1 files changed, 314 insertions, 0 deletions
diff --git a/src/cmd/internal/obj/plist.go b/src/cmd/internal/obj/plist.go
new file mode 100644
index 0000000..2b09699
--- /dev/null
+++ b/src/cmd/internal/obj/plist.go
@@ -0,0 +1,314 @@
+// 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 (
+	"cmd/internal/objabi"
+	"fmt"
+	"strings"
+)
+
+type Plist struct {
+	Firstpc *Prog
+	Curfn   interface{} // holds a *gc.Node, if non-nil
+}
+
+// ProgAlloc is a function that allocates Progs.
+// It is used to provide access to cached/bulk-allocated Progs to the assemblers.
+type ProgAlloc func() *Prog
+
+func Flushplist(ctxt *Link, plist *Plist, newprog ProgAlloc, myimportpath string) {
+	// Build list of symbols, and assign instructions to lists.
+	var curtext *LSym
+	var etext *Prog
+	var text []*LSym
+
+	var plink *Prog
+	for p := plist.Firstpc; p != nil; p = plink {
+		if ctxt.Debugasm > 0 && ctxt.Debugvlog {
+			fmt.Printf("obj: %v\n", p)
+		}
+		plink = p.Link
+		p.Link = nil
+
+		switch p.As {
+		case AEND:
+			continue
+
+		case ATEXT:
+			s := p.From.Sym
+			if s == nil {
+				// func _() { }
+				curtext = nil
+				continue
+			}
+			text = append(text, s)
+			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 != objabi.FUNCDATA_ArgsPointerMaps {
+					ctxt.Diag("FUNCDATA use of go_args_stackmap(SB) without FUNCDATA_ArgsPointerMaps")
+				}
+				p.To.Sym = ctxt.LookupDerived(curtext, curtext.Name+".args_stackmap")
+			}
+
+		}
+
+		if curtext == nil {
+			etext = nil
+			continue
+		}
+		etext.Link = p
+		etext = p
+	}
+
+	if newprog == nil {
+		newprog = ctxt.NewProg
+	}
+
+	// Add reference to Go arguments for C or assembly functions without them.
+	for _, s := range text {
+		if !strings.HasPrefix(s.Name, "\"\".") {
+			continue
+		}
+		found := false
+		for p := s.Func().Text; p != nil; p = p.Link {
+			if p.As == AFUNCDATA && p.From.Type == TYPE_CONST && p.From.Offset == objabi.FUNCDATA_ArgsPointerMaps {
+				found = true
+				break
+			}
+		}
+
+		if !found {
+			p := Appendp(s.Func().Text, newprog)
+			p.As = AFUNCDATA
+			p.From.Type = TYPE_CONST
+			p.From.Offset = objabi.FUNCDATA_ArgsPointerMaps
+			p.To.Type = TYPE_MEM
+			p.To.Name = NAME_EXTERN
+			p.To.Sym = ctxt.LookupDerived(s, s.Name+".args_stackmap")
+		}
+	}
+
+	// Turn functions into machine code images.
+	for _, s := range text {
+		mkfwd(s)
+		linkpatch(ctxt, s, newprog)
+		ctxt.Arch.Preprocess(ctxt, s, newprog)
+		ctxt.Arch.Assemble(ctxt, s, newprog)
+		if ctxt.Errors > 0 {
+			continue
+		}
+		linkpcln(ctxt, s)
+		if myimportpath != "" {
+			ctxt.populateDWARF(plist.Curfn, s, myimportpath)
+		}
+	}
+}
+
+func (ctxt *Link) InitTextSym(s *LSym, flag int) {
+	if s == nil {
+		// func _() { }
+		return
+	}
+	if s.Func() != nil {
+		ctxt.Diag("InitTextSym double init for %s", s.Name)
+	}
+	s.NewFuncInfo()
+	if s.OnList() {
+		ctxt.Diag("symbol %s listed multiple times", s.Name)
+	}
+	name := strings.Replace(s.Name, "\"\"", ctxt.Pkgpath, -1)
+	s.Func().FuncID = objabi.GetFuncID(name, flag&WRAPPER != 0)
+	s.Set(AttrOnList, true)
+	s.Set(AttrDuplicateOK, flag&DUPOK != 0)
+	s.Set(AttrNoSplit, flag&NOSPLIT != 0)
+	s.Set(AttrReflectMethod, flag&REFLECTMETHOD != 0)
+	s.Set(AttrWrapper, flag&WRAPPER != 0)
+	s.Set(AttrNeedCtxt, flag&NEEDCTXT != 0)
+	s.Set(AttrNoFrame, flag&NOFRAME != 0)
+	s.Set(AttrTopFrame, flag&TOPFRAME != 0)
+	s.Type = objabi.STEXT
+	ctxt.Text = append(ctxt.Text, s)
+
+	// Set up DWARF entries for s
+	ctxt.dwarfSym(s)
+}
+
+func (ctxt *Link) Globl(s *LSym, size int64, flag int) {
+	if s.OnList() {
+		ctxt.Diag("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 = objabi.SBSS
+	}
+	if flag&DUPOK != 0 {
+		s.Set(AttrDuplicateOK, true)
+	}
+	if flag&RODATA != 0 {
+		s.Type = objabi.SRODATA
+	} else if flag&NOPTR != 0 {
+		if s.Type == objabi.SDATA {
+			s.Type = objabi.SNOPTRDATA
+		} else {
+			s.Type = objabi.SNOPTRBSS
+		}
+	} else if flag&TLSBSS != 0 {
+		s.Type = objabi.STLSBSS
+	}
+	if strings.HasPrefix(s.Name, "\"\"."+StaticNamePref) {
+		s.Set(AttrStatic, true)
+	}
+}
+
+// EmitEntryLiveness generates PCDATA Progs after p to switch to the
+// liveness map active at the entry of function s. It returns the last
+// Prog generated.
+func (ctxt *Link) EmitEntryLiveness(s *LSym, p *Prog, newprog ProgAlloc) *Prog {
+	pcdata := ctxt.EmitEntryStackMap(s, p, newprog)
+	pcdata = ctxt.EmitEntryUnsafePoint(s, pcdata, newprog)
+	return pcdata
+}
+
+// Similar to EmitEntryLiveness, but just emit stack map.
+func (ctxt *Link) EmitEntryStackMap(s *LSym, p *Prog, newprog ProgAlloc) *Prog {
+	pcdata := Appendp(p, newprog)
+	pcdata.Pos = s.Func().Text.Pos
+	pcdata.As = APCDATA
+	pcdata.From.Type = TYPE_CONST
+	pcdata.From.Offset = objabi.PCDATA_StackMapIndex
+	pcdata.To.Type = TYPE_CONST
+	pcdata.To.Offset = -1 // pcdata starts at -1 at function entry
+
+	return pcdata
+}
+
+// Similar to EmitEntryLiveness, but just emit unsafe point map.
+func (ctxt *Link) EmitEntryUnsafePoint(s *LSym, p *Prog, newprog ProgAlloc) *Prog {
+	pcdata := Appendp(p, newprog)
+	pcdata.Pos = s.Func().Text.Pos
+	pcdata.As = APCDATA
+	pcdata.From.Type = TYPE_CONST
+	pcdata.From.Offset = objabi.PCDATA_UnsafePoint
+	pcdata.To.Type = TYPE_CONST
+	pcdata.To.Offset = -1
+
+	return pcdata
+}
+
+// StartUnsafePoint generates PCDATA Progs after p to mark the
+// beginning of an unsafe point. The unsafe point starts immediately
+// after p.
+// It returns the last Prog generated.
+func (ctxt *Link) StartUnsafePoint(p *Prog, newprog ProgAlloc) *Prog {
+	pcdata := Appendp(p, newprog)
+	pcdata.As = APCDATA
+	pcdata.From.Type = TYPE_CONST
+	pcdata.From.Offset = objabi.PCDATA_UnsafePoint
+	pcdata.To.Type = TYPE_CONST
+	pcdata.To.Offset = objabi.PCDATA_UnsafePointUnsafe
+
+	return pcdata
+}
+
+// EndUnsafePoint generates PCDATA Progs after p to mark the end of an
+// unsafe point, restoring the register map index to oldval.
+// The unsafe point ends right after p.
+// It returns the last Prog generated.
+func (ctxt *Link) EndUnsafePoint(p *Prog, newprog ProgAlloc, oldval int64) *Prog {
+	pcdata := Appendp(p, newprog)
+	pcdata.As = APCDATA
+	pcdata.From.Type = TYPE_CONST
+	pcdata.From.Offset = objabi.PCDATA_UnsafePoint
+	pcdata.To.Type = TYPE_CONST
+	pcdata.To.Offset = oldval
+
+	return pcdata
+}
+
+// MarkUnsafePoints inserts PCDATAs to mark nonpreemptible and restartable
+// instruction sequences, based on isUnsafePoint and isRestartable predicate.
+// p0 is the start of the instruction stream.
+// isUnsafePoint(p) returns true if p is not safe for async preemption.
+// isRestartable(p) returns true if we can restart at the start of p (this Prog)
+// upon async preemption. (Currently multi-Prog restartable sequence is not
+// supported.)
+// isRestartable can be nil. In this case it is treated as always returning false.
+// If isUnsafePoint(p) and isRestartable(p) are both true, it is treated as
+// an unsafe point.
+func MarkUnsafePoints(ctxt *Link, p0 *Prog, newprog ProgAlloc, isUnsafePoint, isRestartable func(*Prog) bool) {
+	if isRestartable == nil {
+		// Default implementation: nothing is restartable.
+		isRestartable = func(*Prog) bool { return false }
+	}
+	prev := p0
+	prevPcdata := int64(-1) // entry PC data value
+	prevRestart := int64(0)
+	for p := prev.Link; p != nil; p, prev = p.Link, p {
+		if p.As == APCDATA && p.From.Offset == objabi.PCDATA_UnsafePoint {
+			prevPcdata = p.To.Offset
+			continue
+		}
+		if prevPcdata == objabi.PCDATA_UnsafePointUnsafe {
+			continue // already unsafe
+		}
+		if isUnsafePoint(p) {
+			q := ctxt.StartUnsafePoint(prev, newprog)
+			q.Pc = p.Pc
+			q.Link = p
+			// Advance to the end of unsafe point.
+			for p.Link != nil && isUnsafePoint(p.Link) {
+				p = p.Link
+			}
+			if p.Link == nil {
+				break // Reached the end, don't bother marking the end
+			}
+			p = ctxt.EndUnsafePoint(p, newprog, prevPcdata)
+			p.Pc = p.Link.Pc
+			continue
+		}
+		if isRestartable(p) {
+			val := int64(objabi.PCDATA_Restart1)
+			if val == prevRestart {
+				val = objabi.PCDATA_Restart2
+			}
+			prevRestart = val
+			q := Appendp(prev, newprog)
+			q.As = APCDATA
+			q.From.Type = TYPE_CONST
+			q.From.Offset = objabi.PCDATA_UnsafePoint
+			q.To.Type = TYPE_CONST
+			q.To.Offset = val
+			q.Pc = p.Pc
+			q.Link = p
+
+			if p.Link == nil {
+				break // Reached the end, don't bother marking the end
+			}
+			if isRestartable(p.Link) {
+				// Next Prog is also restartable. No need to mark the end
+				// of this sequence. We'll just go ahead mark the next one.
+				continue
+			}
+			p = Appendp(p, newprog)
+			p.As = APCDATA
+			p.From.Type = TYPE_CONST
+			p.From.Offset = objabi.PCDATA_UnsafePoint
+			p.To.Type = TYPE_CONST
+			p.To.Offset = prevPcdata
+			p.Pc = p.Link.Pc
+		}
+	}
+}