| // Derived from Inferno utils/6c/txt.c |
| // https://bitbucket.org/inferno-os/inferno-os/src/master/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/ssa" |
| "cmd/compile/internal/types" |
| "cmd/internal/obj" |
| "cmd/internal/objabi" |
| "cmd/internal/src" |
| ) |
| |
| var sharedProgArray = 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 |
| |
| nextLive LivenessIndex // liveness index for the next Prog |
| prevLive LivenessIndex // last emitted liveness index |
| } |
| |
| // 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) |
| // PCDATA tables implicitly start with index -1. |
| pp.prevLive = LivenessIndex{-1, -1, false} |
| if go115ReduceLiveness { |
| pp.nextLive = pp.prevLive |
| } else { |
| pp.nextLive = LivenessInvalid |
| } |
| return pp |
| } |
| |
| func (pp *Progs) NewProg() *obj.Prog { |
| var p *obj.Prog |
| if pp.cacheidx < len(pp.progcache) { |
| p = &pp.progcache[pp.cacheidx] |
| pp.cacheidx++ |
| } else { |
| 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, myimportpath) |
| } |
| |
| // 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 { |
| if pp.nextLive.StackMapValid() && pp.nextLive.stackMapIndex != pp.prevLive.stackMapIndex { |
| // Emit stack map index change. |
| idx := pp.nextLive.stackMapIndex |
| pp.prevLive.stackMapIndex = idx |
| p := pp.Prog(obj.APCDATA) |
| Addrconst(&p.From, objabi.PCDATA_StackMapIndex) |
| Addrconst(&p.To, int64(idx)) |
| } |
| if !go115ReduceLiveness { |
| if pp.nextLive.isUnsafePoint { |
| // Unsafe points are encoded as a special value in the |
| // register map. |
| pp.nextLive.regMapIndex = objabi.PCDATA_RegMapUnsafe |
| } |
| if pp.nextLive.regMapIndex != pp.prevLive.regMapIndex { |
| // Emit register map index change. |
| idx := pp.nextLive.regMapIndex |
| pp.prevLive.regMapIndex = idx |
| p := pp.Prog(obj.APCDATA) |
| Addrconst(&p.From, objabi.PCDATA_RegMapIndex) |
| Addrconst(&p.To, int64(idx)) |
| } |
| } else { |
| if pp.nextLive.isUnsafePoint != pp.prevLive.isUnsafePoint { |
| // Emit unsafe-point marker. |
| pp.prevLive.isUnsafePoint = pp.nextLive.isUnsafePoint |
| p := pp.Prog(obj.APCDATA) |
| Addrconst(&p.From, objabi.PCDATA_UnsafePoint) |
| if pp.nextLive.isUnsafePoint { |
| Addrconst(&p.To, objabi.PCDATA_UnsafePointUnsafe) |
| } else { |
| Addrconst(&p.To, objabi.PCDATA_UnsafePointSafe) |
| } |
| } |
| } |
| |
| 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 |
| if pp.pos.IsStmt() == src.PosIsStmt { |
| // Clear IsStmt for later Progs at this pos provided that as can be marked as a stmt |
| if ssa.LosesStmtMark(as) { |
| return p |
| } |
| pp.pos = pp.pos.WithNotStmt() |
| } |
| 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 |
| |
| fn.Func.lsym.Func.Text = ptxt |
| ptxt.From.Type = obj.TYPE_MEM |
| ptxt.From.Name = obj.NAME_EXTERN |
| ptxt.From.Sym = fn.Func.lsym |
| } |
| |
| // initLSym defines f's obj.LSym and initializes it based on the |
| // properties of f. This includes setting the symbol flags and ABI and |
| // creating and initializing related DWARF symbols. |
| // |
| // initLSym must be called exactly once per function and must be |
| // called for both functions with bodies and functions without bodies. |
| func (f *Func) initLSym(hasBody bool) { |
| if f.lsym != nil { |
| Fatalf("Func.initLSym called twice") |
| } |
| |
| if nam := f.Nname; !nam.isBlank() { |
| f.lsym = nam.Sym.Linksym() |
| if f.Pragma&Systemstack != 0 { |
| f.lsym.Set(obj.AttrCFunc, true) |
| } |
| |
| var aliasABI obj.ABI |
| needABIAlias := false |
| defABI, hasDefABI := symabiDefs[f.lsym.Name] |
| if hasDefABI && defABI == obj.ABI0 { |
| // Symbol is defined as ABI0. Create an |
| // Internal -> ABI0 wrapper. |
| f.lsym.SetABI(obj.ABI0) |
| needABIAlias, aliasABI = true, obj.ABIInternal |
| } else { |
| // No ABI override. Check that the symbol is |
| // using the expected ABI. |
| want := obj.ABIInternal |
| if f.lsym.ABI() != want { |
| Fatalf("function symbol %s has the wrong ABI %v, expected %v", f.lsym.Name, f.lsym.ABI(), want) |
| } |
| } |
| |
| isLinknameExported := nam.Sym.Linkname != "" && (hasBody || hasDefABI) |
| if abi, ok := symabiRefs[f.lsym.Name]; (ok && abi == obj.ABI0) || isLinknameExported { |
| // Either 1) this symbol is definitely |
| // referenced as ABI0 from this package; or 2) |
| // this symbol is defined in this package but |
| // given a linkname, indicating that it may be |
| // referenced from another package. Create an |
| // ABI0 -> Internal wrapper so it can be |
| // called as ABI0. In case 2, it's important |
| // that we know it's defined in this package |
| // since other packages may "pull" symbols |
| // using linkname and we don't want to create |
| // duplicate ABI wrappers. |
| if f.lsym.ABI() != obj.ABI0 { |
| needABIAlias, aliasABI = true, obj.ABI0 |
| } |
| } |
| |
| if needABIAlias { |
| // These LSyms have the same name as the |
| // native function, so we create them directly |
| // rather than looking them up. The uniqueness |
| // of f.lsym ensures uniqueness of asym. |
| asym := &obj.LSym{ |
| Name: f.lsym.Name, |
| Type: objabi.SABIALIAS, |
| R: []obj.Reloc{{Sym: f.lsym}}, // 0 size, so "informational" |
| } |
| asym.SetABI(aliasABI) |
| asym.Set(obj.AttrDuplicateOK, true) |
| Ctxt.ABIAliases = append(Ctxt.ABIAliases, asym) |
| } |
| } |
| |
| if !hasBody { |
| // For body-less functions, we only create the LSym. |
| return |
| } |
| |
| var flag int |
| if f.Dupok() { |
| flag |= obj.DUPOK |
| } |
| if f.Wrapper() { |
| flag |= obj.WRAPPER |
| } |
| 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) |
| if nam.Name.LibfuzzerExtraCounter() { |
| s.Type = objabi.SLIBFUZZER_EXTRA_COUNTER |
| } |
| } |
| |
| 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 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 |
| } |
