ref: 1057a859b8aa0270f330b2fc11118e1f5f924d74
dir: /sys/src/libmach/qobj.c/
/* * qobj.c - identify and parse a PowerPC object file * [email protected] */ #include <u.h> #include <libc.h> #include <bio.h> #include <mach.h> #include "qc/q.out.h" #include "obj.h" typedef struct Addr Addr; struct Addr { char type; char sym; char name; }; static Addr addr(Biobuf*); static char type2char(int); static void skip(Biobuf*, int); int _isq(char *s) { return (s[0]&0377) == ANAME /* ANAME */ && (s[1]&0377) == ANAME>>8 && s[2] == D_FILE /* type */ && s[3] == 1 /* sym */ && s[4] == '<'; /* name of file */ } int _readq(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; n = Bgetc(bp); /* reg and flag */ skip(bp, 4); /* lineno(4) */ a = addr(bp); if(n & 0x40) addr(bp); addr(bp); if(a.type != D_OREG || a.name != D_STATIC && a.name != D_EXTERN) p->kind = aNone; p->sym = a.sym; return 1; } static Addr addr(Biobuf *bp) { Addr a; long off; a.type = Bgetc(bp); /* a.type */ skip(bp,1); /* reg */ a.sym = Bgetc(bp); /* sym index */ a.name = Bgetc(bp); /* sym type */ switch(a.type){ default: case D_NONE: case D_REG: case D_FREG: case D_CREG: case D_FPSCR: case D_MSR: case D_SREG: break; case D_SPR: case D_OREG: case D_DCR: case D_CONST: case D_BRANCH: off = Bgetc(bp); off |= Bgetc(bp) << 8; off |= Bgetc(bp) << 16; off |= Bgetc(bp) << 24; if(off < 0) off = -off; if(a.sym && (a.name==D_PARAM || a.name==D_AUTO)) _offset(a.sym, off); break; case D_SCONST: skip(bp, NSNAME); break; case D_FCONST: skip(bp, 8); break; } 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); }