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// Derived from Inferno utils/6c/txt.c
// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6c/txt.c
//
// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
// Portions Copyright © 1997-1999 Vita Nuova Limited
// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
// Portions Copyright © 2004,2006 Bruce Ellis
// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
// Portions Copyright © 2009 The Go Authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package gc
import (
"cmd/compile/internal/types"
"cmd/internal/obj"
"cmd/internal/objabi"
"cmd/internal/src"
)
var sharedProgArray *[10000]obj.Prog = new([10000]obj.Prog) // *T instead of T to work around issue 19839
// Progs accumulates Progs for a function and converts them into machine code.
type Progs struct {
Text *obj.Prog // ATEXT Prog for this function
next *obj.Prog // next Prog
pc int64 // virtual PC; count of Progs
pos src.XPos // position to use for new Progs
curfn *Node // fn these Progs are for
progcache []obj.Prog // local progcache
cacheidx int // first free element of progcache
}
// newProgs returns a new Progs for fn.
// worker indicates which of the backend workers will use the Progs.
func newProgs(fn *Node, worker int) *Progs {
pp := new(Progs)
if Ctxt.CanReuseProgs() {
sz := len(sharedProgArray) / nBackendWorkers
pp.progcache = sharedProgArray[sz*worker : sz*(worker+1)]
}
pp.curfn = fn
// prime the pump
pp.next = pp.NewProg()
pp.clearp(pp.next)
pp.pos = fn.Pos
pp.settext(fn)
return pp
}
func (pp *Progs) NewProg() *obj.Prog {
if pp.cacheidx < len(pp.progcache) {
p := &pp.progcache[pp.cacheidx]
p.Ctxt = Ctxt
pp.cacheidx++
return p
}
p := new(obj.Prog)
p.Ctxt = Ctxt
return p
}
// Flush converts from pp to machine code.
func (pp *Progs) Flush() {
plist := &obj.Plist{Firstpc: pp.Text, Curfn: pp.curfn}
obj.Flushplist(Ctxt, plist, pp.NewProg)
}
// Free clears pp and any associated resources.
func (pp *Progs) Free() {
if Ctxt.CanReuseProgs() {
// Clear progs to enable GC and avoid abuse.
s := pp.progcache[:pp.cacheidx]
for i := range s {
s[i] = obj.Prog{}
}
}
// Clear pp to avoid abuse.
*pp = Progs{}
}
// Prog adds a Prog with instruction As to pp.
func (pp *Progs) Prog(as obj.As) *obj.Prog {
p := pp.next
pp.next = pp.NewProg()
pp.clearp(pp.next)
p.Link = pp.next
if !pp.pos.IsKnown() && Debug['K'] != 0 {
Warn("prog: unknown position (line 0)")
}
p.As = as
p.Pos = pp.pos
return p
}
func (pp *Progs) clearp(p *obj.Prog) {
obj.Nopout(p)
p.As = obj.AEND
p.Pc = pp.pc
pp.pc++
}
func (pp *Progs) Appendpp(p *obj.Prog, as obj.As, ftype obj.AddrType, freg int16, foffset int64, ttype obj.AddrType, treg int16, toffset int64) *obj.Prog {
q := pp.NewProg()
pp.clearp(q)
q.As = as
q.Pos = p.Pos
q.From.Type = ftype
q.From.Reg = freg
q.From.Offset = foffset
q.To.Type = ttype
q.To.Reg = treg
q.To.Offset = toffset
q.Link = p.Link
p.Link = q
return q
}
func (pp *Progs) settext(fn *Node) {
if pp.Text != nil {
Fatalf("Progs.settext called twice")
}
ptxt := pp.Prog(obj.ATEXT)
pp.Text = ptxt
if fn.Func.lsym == nil {
// func _() { }
return
}
fn.Func.lsym.Func.Text = ptxt
ptxt.From.Type = obj.TYPE_MEM
ptxt.From.Name = obj.NAME_EXTERN
ptxt.From.Sym = fn.Func.lsym
p := pp.Prog(obj.AFUNCDATA)
Addrconst(&p.From, objabi.FUNCDATA_ArgsPointerMaps)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = &fn.Func.lsym.Func.GCArgs
p = pp.Prog(obj.AFUNCDATA)
Addrconst(&p.From, objabi.FUNCDATA_LocalsPointerMaps)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = &fn.Func.lsym.Func.GCLocals
}
func (f *Func) initLSym() {
if f.lsym != nil {
Fatalf("Func.initLSym called twice")
}
if nam := f.Nname; !isblank(nam) {
f.lsym = nam.Sym.Linksym()
if f.Pragma&Systemstack != 0 {
f.lsym.Set(obj.AttrCFunc, true)
}
}
var flag int
if f.Dupok() {
flag |= obj.DUPOK
}
if f.Wrapper() {
flag |= obj.WRAPPER
}
if f.NoFramePointer() {
flag |= obj.NOFRAME
}
if f.Needctxt() {
flag |= obj.NEEDCTXT
}
if f.Pragma&Nosplit != 0 {
flag |= obj.NOSPLIT
}
if f.ReflectMethod() {
flag |= obj.REFLECTMETHOD
}
// Clumsy but important.
// See test/recover.go for test cases and src/reflect/value.go
// for the actual functions being considered.
if myimportpath == "reflect" {
switch f.Nname.Sym.Name {
case "callReflect", "callMethod":
flag |= obj.WRAPPER
}
}
Ctxt.InitTextSym(f.lsym, flag)
}
func ggloblnod(nam *Node) {
s := nam.Sym.Linksym()
s.Gotype = ngotype(nam).Linksym()
flags := 0
if nam.Name.Readonly() {
flags = obj.RODATA
}
if nam.Type != nil && !types.Haspointers(nam.Type) {
flags |= obj.NOPTR
}
Ctxt.Globl(s, nam.Type.Width, flags)
}
func ggloblsym(s *obj.LSym, width int32, flags int16) {
if flags&obj.LOCAL != 0 {
s.Set(obj.AttrLocal, true)
flags &^= obj.LOCAL
}
Ctxt.Globl(s, int64(width), int(flags))
}
func isfat(t *types.Type) bool {
if t != nil {
switch t.Etype {
case TSTRUCT, TARRAY, TSLICE, TSTRING,
TINTER: // maybe remove later
return true
}
}
return false
}
func Addrconst(a *obj.Addr, v int64) {
a.Sym = nil
a.Type = obj.TYPE_CONST
a.Offset = v
}
func Patch(p *obj.Prog, to *obj.Prog) {
if p.To.Type != obj.TYPE_BRANCH {
Fatalf("patch: not a branch")
}
p.To.Val = to
p.To.Offset = to.Pc
}