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1.1 ! root 1: /* ! 2: * 8obj.c - identify and parse a 386 object file ! 3: */ ! 4: #include <u.h> ! 5: #include <libc.h> ! 6: #include <bio.h> ! 7: #include "8c/8.out.h" ! 8: #include "obj.h" ! 9: ! 10: typedef struct Addr Addr; ! 11: struct Addr ! 12: { ! 13: char sym; ! 14: char flags; ! 15: }; ! 16: static Addr addr(Biobuf*); ! 17: static char type2char(int); ! 18: static void skip(Biobuf*, int); ! 19: ! 20: int ! 21: _is8(char *t) ! 22: { ! 23: uchar *s = (uchar*)t; ! 24: ! 25: return s[0] == (ANAME&0xff) /* aslo = ANAME */ ! 26: && s[1] == ((ANAME>>8)&0xff) ! 27: && s[2] == D_FILE /* type */ ! 28: && s[3] == 1 /* sym */ ! 29: && s[4] == '<'; /* name of file */ ! 30: } ! 31: ! 32: int ! 33: _read8(Biobuf *bp, Prog* p) ! 34: { ! 35: int as, n, c; ! 36: Addr a; ! 37: ! 38: as = Bgetc(bp); /* as(low) */ ! 39: if(as < 0) ! 40: return 0; ! 41: c = Bgetc(bp); /* as(high) */ ! 42: if(c < 0) ! 43: return 0; ! 44: as |= ((c & 0xff) << 8); ! 45: p->kind = aNone; ! 46: if(as == ANAME){ ! 47: p->kind = aName; ! 48: p->type = type2char(Bgetc(bp)); /* type */ ! 49: p->sym = Bgetc(bp); /* sym */ ! 50: n = 0; ! 51: for(;;) { ! 52: as = Bgetc(bp); ! 53: if(as < 0) ! 54: return 0; ! 55: n++; ! 56: if(as == 0) ! 57: break; ! 58: } ! 59: p->id = malloc(n); ! 60: if(p->id == 0) ! 61: return 0; ! 62: Bseek(bp, -n, 1); ! 63: if(Bread(bp, p->id, n) != n) ! 64: return 0; ! 65: return 1; ! 66: } ! 67: if(as == ATEXT) ! 68: p->kind = aText; ! 69: if(as == AGLOBL) ! 70: p->kind = aData; ! 71: skip(bp, 4); /* lineno(4) */ ! 72: a = addr(bp); ! 73: addr(bp); ! 74: if(!(a.flags & T_SYM)) ! 75: p->kind = aNone; ! 76: p->sym = a.sym; ! 77: return 1; ! 78: } ! 79: ! 80: static Addr ! 81: addr(Biobuf *bp) ! 82: { ! 83: Addr a; ! 84: int t; ! 85: long off; ! 86: ! 87: off = 0; ! 88: a.sym = -1; ! 89: a.flags = Bgetc(bp); /* flags */ ! 90: if(a.flags & T_INDEX) ! 91: skip(bp, 2); ! 92: if(a.flags & T_OFFSET){ ! 93: off = Bgetc(bp); ! 94: off |= Bgetc(bp) << 8; ! 95: off |= Bgetc(bp) << 16; ! 96: off |= Bgetc(bp) << 24; ! 97: if(off < 0) ! 98: off = -off; ! 99: } ! 100: if(a.flags & T_SYM) ! 101: a.sym = Bgetc(bp); ! 102: if(a.flags & T_FCONST) ! 103: skip(bp, 8); ! 104: else ! 105: if(a.flags & T_SCONST) ! 106: skip(bp, NSNAME); ! 107: if(a.flags & T_TYPE) { ! 108: t = Bgetc(bp); ! 109: if(a.sym > 0 && (t==D_PARAM || t==D_AUTO)) ! 110: _offset(a.sym, off); ! 111: } ! 112: return a; ! 113: } ! 114: ! 115: static char ! 116: type2char(int t) ! 117: { ! 118: switch(t){ ! 119: case D_EXTERN: return 'U'; ! 120: case D_STATIC: return 'b'; ! 121: case D_AUTO: return 'a'; ! 122: case D_PARAM: return 'p'; ! 123: default: return UNKNOWN; ! 124: } ! 125: } ! 126: ! 127: static void ! 128: skip(Biobuf *bp, int n) ! 129: { ! 130: while (n-- > 0) ! 131: Bgetc(bp); ! 132: }
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