| // Inferno utils/6l/pass.c |
| // http://code.google.com/p/inferno-os/source/browse/utils/6l/pass.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 obj |
| |
| // Code and data passes. |
| |
| func Brchain(ctxt *Link, p *Prog) *Prog { |
| for i := 0; i < 20; i++ { |
| if p == nil || p.As != AJMP || p.Pcond == nil { |
| return p |
| } |
| p = p.Pcond |
| } |
| |
| return nil |
| } |
| |
| func brloop(ctxt *Link, p *Prog) *Prog { |
| var q *Prog |
| |
| c := 0 |
| for q = p; q != nil; q = q.Pcond { |
| if q.As != AJMP || q.Pcond == nil { |
| break |
| } |
| c++ |
| if c >= 5000 { |
| return nil |
| } |
| } |
| |
| return q |
| } |
| |
| func checkaddr(ctxt *Link, p *Prog, a *Addr) { |
| // Check expected encoding, especially TYPE_CONST vs TYPE_ADDR. |
| switch a.Type { |
| case TYPE_NONE: |
| return |
| |
| case TYPE_BRANCH: |
| if a.Reg != 0 || a.Index != 0 || a.Scale != 0 || a.Name != 0 { |
| break |
| } |
| return |
| |
| case TYPE_TEXTSIZE: |
| if a.Reg != 0 || a.Index != 0 || a.Scale != 0 || a.Name != 0 { |
| break |
| } |
| return |
| |
| //if(a->u.bits != 0) |
| // break; |
| case TYPE_MEM: |
| return |
| |
| // TODO(rsc): After fixing SHRQ, check a->index != 0 too. |
| case TYPE_CONST: |
| if a.Name != 0 || a.Sym != nil || a.Reg != 0 { |
| ctxt.Diag("argument is TYPE_CONST, should be TYPE_ADDR, in %v", p) |
| return |
| } |
| |
| if a.Reg != 0 || a.Scale != 0 || a.Name != 0 || a.Sym != nil || a.U.Bits != 0 { |
| break |
| } |
| return |
| |
| case TYPE_FCONST, |
| TYPE_SCONST: |
| if a.Reg != 0 || a.Index != 0 || a.Scale != 0 || a.Name != 0 || a.Offset != 0 || a.Sym != nil { |
| break |
| } |
| return |
| |
| // TODO(rsc): After fixing PINSRQ, check a->offset != 0 too. |
| // TODO(rsc): After fixing SHRQ, check a->index != 0 too. |
| case TYPE_REG: |
| if a.Scale != 0 || a.Name != 0 || a.Sym != nil { |
| break |
| } |
| return |
| |
| case TYPE_ADDR: |
| if a.U.Bits != 0 { |
| break |
| } |
| if a.Reg == 0 && a.Index == 0 && a.Scale == 0 && a.Name == 0 && a.Sym == nil { |
| ctxt.Diag("argument is TYPE_ADDR, should be TYPE_CONST, in %v", p) |
| } |
| return |
| |
| case TYPE_SHIFT: |
| if a.Index != 0 || a.Scale != 0 || a.Name != 0 || a.Sym != nil || a.U.Bits != 0 { |
| break |
| } |
| return |
| |
| case TYPE_REGREG: |
| if a.Index != 0 || a.Scale != 0 || a.Name != 0 || a.Sym != nil || a.U.Bits != 0 { |
| break |
| } |
| return |
| |
| case TYPE_REGREG2: |
| return |
| |
| // Expect sym and name to be set, nothing else. |
| // Technically more is allowed, but this is only used for *name(SB). |
| case TYPE_INDIR: |
| if a.Reg != 0 || a.Index != 0 || a.Scale != 0 || a.Name == 0 || a.Offset != 0 || a.Sym == nil || a.U.Bits != 0 { |
| break |
| } |
| return |
| } |
| |
| ctxt.Diag("invalid encoding for argument %v", p) |
| } |
| |
| func linkpatch(ctxt *Link, sym *LSym) { |
| var c int32 |
| var name string |
| var q *Prog |
| |
| ctxt.Cursym = sym |
| |
| for p := sym.Text; p != nil; p = p.Link { |
| checkaddr(ctxt, p, &p.From) |
| checkaddr(ctxt, p, &p.From3) |
| checkaddr(ctxt, p, &p.To) |
| |
| if ctxt.Arch.Progedit != nil { |
| ctxt.Arch.Progedit(ctxt, p) |
| } |
| if p.To.Type != TYPE_BRANCH { |
| continue |
| } |
| if p.To.U.Branch != nil { |
| // TODO: Remove to.u.branch in favor of p->pcond. |
| p.Pcond = p.To.U.Branch |
| |
| continue |
| } |
| |
| if p.To.Sym != nil { |
| continue |
| } |
| c = int32(p.To.Offset) |
| for q = sym.Text; q != nil; { |
| if int64(c) == q.Pc { |
| break |
| } |
| if q.Forwd != nil && int64(c) >= q.Forwd.Pc { |
| q = q.Forwd |
| } else { |
| q = q.Link |
| } |
| } |
| |
| if q == nil { |
| name = "<nil>" |
| if p.To.Sym != nil { |
| name = p.To.Sym.Name |
| } |
| ctxt.Diag("branch out of range (%#x)\n%v [%s]", uint32(c), p, name) |
| p.To.Type = TYPE_NONE |
| } |
| |
| p.To.U.Branch = q |
| p.Pcond = q |
| } |
| |
| for p := sym.Text; p != nil; p = p.Link { |
| p.Mark = 0 /* initialization for follow */ |
| if p.Pcond != nil { |
| p.Pcond = brloop(ctxt, p.Pcond) |
| if p.Pcond != nil { |
| if p.To.Type == TYPE_BRANCH { |
| p.To.Offset = p.Pcond.Pc |
| } |
| } |
| } |
| } |
| } |