// 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.
// Code and data passes.
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <link.h>
Prog*
brchain(Link *ctxt, Prog *p)
{
int i;
for(i=0; i<20; i++) {
if(p == nil || p->as != ctxt->arch->AJMP)
return p;
p = p->pcond;
}
return nil;
}
Prog*
brloop(Link *ctxt, Prog *p)
{
int c;
Prog *q;
c = 0;
for(q = p; q != nil; q = q->pcond) {
if(q->as != ctxt->arch->AJMP)
break;
c++;
if(c >= 5000)
return nil;
}
return q;
}
void
linkpatch(Link *ctxt, LSym *sym)
{
int32 c;
Prog *p, *q;
ctxt->cursym = sym;
for(p = sym->text; p != nil; p = p->link) {
if(ctxt->arch->progedit)
ctxt->arch->progedit(ctxt, p);
if(p->to.type != ctxt->arch->D_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 = p->to.offset;
for(q = sym->text; q != nil;) {
if(c == q->pc)
break;
if(q->forwd != nil && c >= q->forwd->pc)
q = q->forwd;
else
q = q->link;
}
if(q == nil) {
ctxt->diag("branch out of range (%#ux)\n%P [%s]",
c, p, p->to.sym ? p->to.sym->name : "<nil>");
p->to.type = ctxt->arch->D_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 == ctxt->arch->D_BRANCH)
p->to.offset = p->pcond->pc;
}
}
}