ref: ad26dc48a6dc05da02f96e5f1e7b82de58ff5b2c
dir: /sys/src/libmach/obj.c/
/* * obj.c * routines universal to all object files */ #include <u.h> #include <libc.h> #include <bio.h> #include <ar.h> #include <mach.h> #include "obj.h" #define islocal(t) ((t)=='a' || (t)=='p') enum { NNAMES = 50, MAXIS = 8, /* max length to determine if a file is a .? file */ MAXOFF = 0x7fffffff, /* larger than any possible local offset */ NHASH = 1024, /* must be power of two */ HASHMUL = 79L, }; int _is2(char*), /* in [$OS].c */ _is5(char*), _is6(char*), _is7(char*), _is8(char*), _is9(char*), _isk(char*), _isq(char*), _isv(char*), _isu(char*), _read2(Biobuf*, Prog*), _read5(Biobuf*, Prog*), _read6(Biobuf*, Prog*), _read7(Biobuf*, Prog*), _read8(Biobuf*, Prog*), _read9(Biobuf*, Prog*), _readk(Biobuf*, Prog*), _readq(Biobuf*, Prog*), _readv(Biobuf*, Prog*), _readu(Biobuf*, Prog*); typedef struct Obj Obj; typedef struct Symtab Symtab; struct Obj /* functions to handle each intermediate (.$O) file */ { char *name; /* name of each $O file */ int (*is)(char*); /* test for each type of $O file */ int (*read)(Biobuf*, Prog*); /* read for each type of $O file*/ }; static Obj obj[] = { /* functions to identify and parse each type of obj */ [Obj68020] "68020 .2", _is2, _read2, [ObjAmd64] "amd64 .6", _is6, _read6, [ObjArm] "arm .5", _is5, _read5, [ObjArm64] "arm64 .7", _is7, _read7, [Obj386] "386 .8", _is8, _read8, [ObjSparc] "sparc .k", _isk, _readk, [ObjPower] "power .q", _isq, _readq, [ObjMips] "mips .v", _isv, _readv, [ObjSparc64] "sparc64 .u", _isu, _readu, [ObjPower64] "power64 .9", _is9, _read9, [Maxobjtype] 0, 0 }; struct Symtab { struct Sym s; struct Symtab *next; }; static Symtab *hash[NHASH]; static Sym *names[NNAMES]; /* working set of active names */ static int processprog(Prog*,int); /* decode each symbol reference */ static void objreset(void); static void objlookup(int, char *, int, uint); static void objupdate(int, int); int objtype(Biobuf *bp, char **name) { int i; char buf[MAXIS]; if(Bread(bp, buf, MAXIS) < MAXIS) return -1; Bseek(bp, -MAXIS, 1); for (i = 0; i < Maxobjtype; i++) { if (obj[i].is && (*obj[i].is)(buf)) { if (name) *name = obj[i].name; return i; } } return -1; } int isar(Biobuf *bp) { int n; char magbuf[SARMAG]; n = Bread(bp, magbuf, SARMAG); if(n == SARMAG && strncmp(magbuf, ARMAG, SARMAG) == 0) return 1; return 0; } /* * determine what kind of object file this is and process it. * return whether or not this was a recognized intermediate file. */ int readobj(Biobuf *bp, int objtype) { Prog p; if (objtype < 0 || objtype >= Maxobjtype || obj[objtype].is == 0) return 1; objreset(); while ((*obj[objtype].read)(bp, &p)) if (!processprog(&p, 1)) return 0; return 1; } int readar(Biobuf *bp, int objtype, vlong end, int doautos) { Prog p; if (objtype < 0 || objtype >= Maxobjtype || obj[objtype].is == 0) return 1; objreset(); while ((*obj[objtype].read)(bp, &p) && Boffset(bp) < end) if (!processprog(&p, doautos)) return 0; return 1; } /* * decode a symbol reference or definition */ static int processprog(Prog *p, int doautos) { if(p->kind == aNone) return 1; if(p->sym < 0 || p->sym >= NNAMES) return 0; switch(p->kind) { case aName: if (!doautos) if(p->type != 'U' && p->type != 'b') break; objlookup(p->sym, p->id, p->type, p->sig); break; case aText: objupdate(p->sym, 'T'); break; case aData: objupdate(p->sym, 'D'); break; default: break; } return 1; } /* * find the entry for s in the symbol array. * make a new entry if it is not already there. */ static void objlookup(int id, char *name, int type, uint sig) { long h; char *cp; Sym *s; Symtab *sp; s = names[id]; if(s && strcmp(s->name, name) == 0) { s->type = type; s->sig = sig; return; } h = *name; for(cp = name+1; *cp; h += *cp++) h *= HASHMUL; if(h < 0) h = ~h; h &= (NHASH-1); if (type == 'U' || type == 'b' || islocal(type)) { for(sp = hash[h]; sp; sp = sp->next) if(strcmp(sp->s.name, name) == 0) { switch(sp->s.type) { case 'T': case 'D': case 'U': if (type == 'U') { names[id] = &sp->s; return; } break; case 't': case 'd': case 'b': if (type == 'b') { names[id] = &sp->s; return; } break; case 'a': case 'p': if (islocal(type)) { names[id] = &sp->s; return; } break; default: break; } } } sp = malloc(sizeof(Symtab)); sp->s.name = name; sp->s.type = type; sp->s.sig = sig; sp->s.value = islocal(type) ? MAXOFF : 0; names[id] = &sp->s; sp->next = hash[h]; hash[h] = sp; return; } /* * traverse the symbol lists */ void objtraverse(void (*fn)(Sym*, void*), void *pointer) { int i; Symtab *s; for(i = 0; i < NHASH; i++) for(s = hash[i]; s; s = s->next) (*fn)(&s->s, pointer); } /* * update the offset information for a 'a' or 'p' symbol in an intermediate file */ void _offset(int id, vlong off) { Sym *s; s = names[id]; if (s && s->name[0] && islocal(s->type) && s->value > off) s->value = off; } /* * update the type of a global text or data symbol */ static void objupdate(int id, int type) { Sym *s; s = names[id]; if (s && s->name[0]) if (s->type == 'U') s->type = type; else if (s->type == 'b') s->type = tolower(type); } /* * look for the next file in an archive */ int nextar(Biobuf *bp, int offset, char *buf) { struct ar_hdr a; int i, r; long arsize; if (offset&01) offset++; Bseek(bp, offset, 0); r = Bread(bp, &a, SAR_HDR); if(r != SAR_HDR) return 0; if(strncmp(a.fmag, ARFMAG, sizeof(a.fmag))) return -1; for(i=0; i<sizeof(a.name) && i<SARNAME && a.name[i] != ' '; i++) buf[i] = a.name[i]; buf[i] = 0; arsize = strtol(a.size, 0, 0); if (arsize&1) arsize++; return arsize + SAR_HDR; } static void objreset(void) { int i; Symtab *s, *n; for(i = 0; i < NHASH; i++) { for(s = hash[i]; s; s = n) { n = s->next; free(s->s.name); free(s); } hash[i] = 0; } memset(names, 0, sizeof names); }