ref: 39fb26df70b6d8878953ff18046cdc12817a2e42
dir: /sys/src/libmach/2obj.c/
/* * 2obj.c - identify and parse a 68020 object file */ #include <u.h> #include <libc.h> #include <bio.h> #include <mach.h> #include "2c/2.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 _is2(char *t) { uchar *s = (uchar *)t; return s[0] == (ANAME&0xff) /* aslo = ANAME */ && s[1] == ((ANAME>>8)&0xff) /* ashi = ANAME */ && s[2] == D_FILE /* type */ && s[3] == 1 /* sym */ && s[4] == '<'; /* name of file */ } int _read2(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 = beswal(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; else if(as == AGLOBL) p->kind = aData; skip(bp, 4); /*lineno: low, high, lowhigh, highigh*/ 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 off; a.flags = Bgetc(bp); /* flags */ a.sym = -1; off = 0; if(a.flags & T_FIELD) skip(bp, 2); if(a.flags & T_INDEX) skip(bp, 7); if(a.flags & T_OFFSET){ off = Bgetc(bp); off |= Bgetc(bp) << 8; off |= Bgetc(bp) << 16; off |= Bgetc(bp) << 24; 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); else{ t = Bgetc(bp); if(a.flags & T_TYPE) t |= Bgetc(bp) << 8; t &= D_MASK; 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); }