ref: 540373b9f603825f27f853a441c6c046a04a0972
dir: /sys/src/libmach/6obj.c/
/* * 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); }