| // 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/internal/obj" |
| "cmd/internal/src" |
| ) |
| |
| // 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 |
| } |
| |
| // newProgs returns a new Progs for fn. |
| func newProgs(fn *Node) *Progs { |
| pp := new(Progs) |
| pp.curfn = fn |
| |
| // prime the pump |
| pp.next = Ctxt.NewProg() |
| pp.clearp(pp.next) |
| |
| pp.pos = fn.Pos |
| pp.settext(fn) |
| return pp |
| } |
| |
| // Flush converts from pp to machine code. |
| func (pp *Progs) Flush() { |
| plist := &obj.Plist{Firstpc: pp.Text, Curfn: pp.curfn} |
| obj.Flushplist(Ctxt, plist) |
| // Clear pp to enable GC and 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 = Ctxt.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 := Ctxt.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) |
| if nam := fn.Func.Nname; !isblank(nam) { |
| ptxt.From.Type = obj.TYPE_MEM |
| ptxt.From.Name = obj.NAME_EXTERN |
| ptxt.From.Sym = Linksym(nam.Sym) |
| if fn.Func.Pragma&Systemstack != 0 { |
| ptxt.From.Sym.Set(obj.AttrCFunc, true) |
| } |
| } |
| |
| 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.NoFramePointer() { |
| ptxt.From3.Offset |= obj.NOFRAME |
| } |
| 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 |
| } |
| |
| // 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 fn.Func.Nname.Sym.Name { |
| case "callReflect", "callMethod": |
| ptxt.From3.Offset |= obj.WRAPPER |
| } |
| } |
| |
| pp.Text = ptxt |
| } |
| |
| func ggloblnod(nam *Node) { |
| s := Linksym(nam.Sym) |
| s.Gotype = Linksym(ngotype(nam)) |
| flags := 0 |
| if nam.Name.Readonly() { |
| flags = obj.RODATA |
| } |
| if nam.Type != nil && !haspointers(nam.Type) { |
| flags |= obj.NOPTR |
| } |
| Ctxt.Globl(s, nam.Type.Width, flags) |
| } |
| |
| func ggloblsym(s *Sym, width int32, flags int16) { |
| ggloblLSym(Linksym(s), width, flags) |
| } |
| |
| func ggloblLSym(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 *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 |
| } |
| |
| // nodarg returns a Node for the function argument denoted by t, |
| // which is either the entire function argument or result struct (t is a struct *Type) |
| // or a specific argument (t is a *Field within a struct *Type). |
| // |
| // If fp is 0, the node is for use by a caller invoking the given |
| // function, preparing the arguments before the call |
| // or retrieving the results after the call. |
| // In this case, the node will correspond to an outgoing argument |
| // slot like 8(SP). |
| // |
| // If fp is 1, the node is for use by the function itself |
| // (the callee), to retrieve its arguments or write its results. |
| // In this case the node will be an ONAME with an appropriate |
| // type and offset. |
| func nodarg(t interface{}, fp int) *Node { |
| var n *Node |
| |
| var funarg Funarg |
| switch t := t.(type) { |
| default: |
| Fatalf("bad nodarg %T(%v)", t, t) |
| |
| case *Type: |
| // Entire argument struct, not just one arg |
| if !t.IsFuncArgStruct() { |
| Fatalf("nodarg: bad type %v", t) |
| } |
| funarg = t.StructType().Funarg |
| |
| // Build fake variable name for whole arg struct. |
| n = newname(lookup(".args")) |
| n.Type = t |
| first := t.Field(0) |
| if first == nil { |
| Fatalf("nodarg: bad struct") |
| } |
| if first.Offset == BADWIDTH { |
| Fatalf("nodarg: offset not computed for %v", t) |
| } |
| n.Xoffset = first.Offset |
| |
| case *Field: |
| funarg = t.Funarg |
| if fp == 1 { |
| // NOTE(rsc): This should be using t.Nname directly, |
| // except in the case where t.Nname.Sym is the blank symbol and |
| // so the assignment would be discarded during code generation. |
| // In that case we need to make a new node, and there is no harm |
| // in optimization passes to doing so. But otherwise we should |
| // definitely be using the actual declaration and not a newly built node. |
| // The extra Fatalf checks here are verifying that this is the case, |
| // without changing the actual logic (at time of writing, it's getting |
| // toward time for the Go 1.7 beta). |
| // At some quieter time (assuming we've never seen these Fatalfs happen) |
| // we could change this code to use "expect" directly. |
| expect := t.Nname |
| if expect.isParamHeapCopy() { |
| expect = expect.Name.Param.Stackcopy |
| } |
| |
| for _, n := range Curfn.Func.Dcl { |
| if (n.Class == PPARAM || n.Class == PPARAMOUT) && !isblanksym(t.Sym) && n.Sym == t.Sym { |
| if n != expect { |
| Fatalf("nodarg: unexpected node: %v (%p %v) vs %v (%p %v)", n, n, n.Op, t.Nname, t.Nname, t.Nname.Op) |
| } |
| return n |
| } |
| } |
| |
| if !isblanksym(expect.Sym) { |
| Fatalf("nodarg: did not find node in dcl list: %v", expect) |
| } |
| } |
| |
| // Build fake name for individual variable. |
| // This is safe because if there was a real declared name |
| // we'd have used it above. |
| n = newname(lookup("__")) |
| n.Type = t.Type |
| if t.Offset == BADWIDTH { |
| Fatalf("nodarg: offset not computed for %v", t) |
| } |
| n.Xoffset = t.Offset |
| n.Orig = t.Nname |
| } |
| |
| // Rewrite argument named _ to __, |
| // or else the assignment to _ will be |
| // discarded during code generation. |
| if isblank(n) { |
| n.Sym = lookup("__") |
| } |
| |
| switch fp { |
| default: |
| Fatalf("bad fp") |
| |
| case 0: // preparing arguments for call |
| n.Op = OINDREGSP |
| n.Xoffset += Ctxt.FixedFrameSize() |
| |
| case 1: // reading arguments inside call |
| n.Class = PPARAM |
| if funarg == FunargResults { |
| n.Class = PPARAMOUT |
| } |
| } |
| |
| n.Typecheck = 1 |
| n.SetAddrtaken(true) // keep optimizers at bay |
| return n |
| } |
| |
| 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 |
| } |
