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/*
* 6obj.c - identify and parse an amd64 object file
*/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <mach.h>
#include "6c/6.out.h"
#include "obj.h"
typedef struct Addr Addr;
struct Addr
{
char sym;
char flags;
};
static Addr addr(Biobuf*);
static char type2char(int);
static void skip(Biobuf*, int);
int
_is6(char *t)
{
uchar *s = (uchar*)t;
return s[0] == (ANAME&0xff) /* aslo = ANAME */
&& s[1] == ((ANAME>>8)&0xff)
&& s[2] == D_FILE /* type */
&& s[3] == 1 /* sym */
&& s[4] == '<'; /* name of file */
}
int
_read6(Biobuf *bp, Prog* p)
{
int as, n, c;
Addr a;
as = Bgetc(bp); /* as(low) */
if(as < 0)
return 0;
c = Bgetc(bp); /* as(high) */
if(c < 0)
return 0;
as |= ((c & 0xff) << 8);
p->kind = aNone;
p->sig = 0;
if(as == ANAME || as == ASIGNAME){
if(as == ASIGNAME){
Bread(bp, &p->sig, 4);
p->sig = leswal(p->sig);
}
p->kind = aName;
p->type = type2char(Bgetc(bp)); /* type */
p->sym = Bgetc(bp); /* sym */
n = 0;
for(;;) {
as = Bgetc(bp);
if(as < 0)
return 0;
n++;
if(as == 0)
break;
}
p->id = malloc(n);
if(p->id == 0)
return 0;
Bseek(bp, -n, 1);
if(Bread(bp, p->id, n) != n)
return 0;
return 1;
}
if(as == ATEXT)
p->kind = aText;
if(as == AGLOBL)
p->kind = aData;
skip(bp, 4); /* lineno(4) */
a = addr(bp);
addr(bp);
if(!(a.flags & T_SYM))
p->kind = aNone;
p->sym = a.sym;
return 1;
}
static Addr
addr(Biobuf *bp)
{
Addr a;
int t;
long l;
vlong off;
off = 0;
a.sym = -1;
a.flags = Bgetc(bp); /* flags */
if(a.flags & T_INDEX)
skip(bp, 2);
if(a.flags & T_OFFSET){
l = Bgetc(bp);
l |= Bgetc(bp) << 8;
l |= Bgetc(bp) << 16;
l |= Bgetc(bp) << 24;
off = l;
if(a.flags & T_64){
l = Bgetc(bp);
l |= Bgetc(bp) << 8;
l |= Bgetc(bp) << 16;
l |= Bgetc(bp) << 24;
off = ((vlong)l << 32) | (off & 0xFFFFFFFF);
}
if(off < 0)
off = -off;
}
if(a.flags & T_SYM)
a.sym = Bgetc(bp);
if(a.flags & T_FCONST)
skip(bp, 8);
else
if(a.flags & T_SCONST)
skip(bp, NSNAME);
if(a.flags & T_TYPE) {
t = Bgetc(bp);
if(a.sym > 0 && (t==D_PARAM || t==D_AUTO))
_offset(a.sym, off);
}
return a;
}
static char
type2char(int t)
{
switch(t){
case D_EXTERN: return 'U';
case D_STATIC: return 'b';
case D_AUTO: return 'a';
case D_PARAM: return 'p';
default: return UNKNOWN;
}
}
static void
skip(Biobuf *bp, int n)
{
while (n-- > 0)
Bgetc(bp);
}
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