ref: e96b586c7023078936c3a1b1081b9239288b9567
dir: /src/cmd/ld/pass1.c/
#include <ctype.h> #include <stdarg.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <scc/mach.h> #include <scc/scc.h> #include <scc/ar.h> #include "ld.h" enum { OUTLIB, INLIB, }; int bintype = -1; static Objops *binops; static Symbol refhead = { .next = &refhead, .prev = &refhead, }; Symbol defhead = { .next = &defhead, .prev = &defhead, }; static Objlst *objlast; Objlst *objhead; static Symbol * linksym(Symbol *list, Symbol *sym) { sym->next = list; sym->prev = list->prev; list->prev->next = sym; list->prev = sym; return sym; } static Symbol * unlinksym(Symbol *sym) { sym->next->prev = sym->prev; sym->prev->next = sym->next; return sym; } static Symbol * undef(char *name) { return linksym(&refhead, install(name)); } static Symbol * define(Objsym *osym, Obj *obj) { Symbol *sym = lookup(osym->name); if (!sym) { sym = undef(osym->name); } else if (sym->def && sym->def->type != 'C') { error("%s: symbol redefined", osym->name); return NULL; } /* TODO: deal with C symbols */ sym->obj = obj; sym->def = osym; sym->size = osym->size; sym->value = osym->value; unlinksym(sym); linksym(&defhead, sym); return sym; } static int moreundef(void) { return refhead.next != &refhead; } static void listundef(void) { Symbol *sym; for (sym = refhead.next; sym != &refhead; sym = sym->next) { fprintf(stderr, "ld: symbol '%s' not defined\n", sym->name); } } static int is_needed(Obj *obj) { Symbol *sym; for (sym = refhead.next; sym != &refhead; sym = sym->next) { if (objlookup(obj, sym->name, 0)) return 1; } return 0; } static int newsym(Objsym *osym, Obj *obj) { Symbol *sym; switch (osym->type) { case 'U': if ((sym = lookup(osym->name)) == NULL) sym = undef(osym->name); break; case '?': case 'N': break; case 'C': sym = lookup(osym->name); if (!sym || !sym->def) { sym = define(osym, obj); break; } if (sym->def->type != 'C') break; if (sym->size < osym->size) sym->size = osym->size; break; default: if (isupper(osym->type)) define(osym, obj); break; } return 1; } static void addobj(Obj *obj, FILE *fp) { int n; Objlst *lst; Objsym *sym; Objsect *secp; if ((lst = malloc(sizeof(*lst))) == NULL) { error("out of memory"); return; } lst->obj = obj; lst->next = NULL; if (!objlast) objlast = objhead = lst; else objlast = objlast->next = lst; for (sym = obj->syms; sym; sym = sym->next) newsym(sym, obj); } static void newobject(FILE *fp, int type, int inlib) { Obj *obj; if (bintype != -1 && bintype != type) { error("not compatible object file"); return; } bintype = type; binops = obj->ops; if ((obj = objnew(type)) == NULL) { error("out of memory"); return; } if ((*binops->read)(obj, fp) < 0) { error("object file corrupted"); goto delete; } if (inlib && !is_needed(obj)) goto delete; addobj(obj, fp); return; delete: (*binops->del)(obj); return; } static void addlib(FILE *fp) { int t, added; long n; Objsymdef *def, *dp; Symbol *sym; if ((*binops->getidx)(&n, &def, fp) < 0) { error("corrupted index"); return; } for (added = 0; moreundef(); added = 0) { for (dp = def; dp; dp = dp->next) { sym = lookup(dp->name); if (!sym || sym->def) continue; if (fseek(fp, dp->offset, SEEK_SET) == EOF) { error(errstr()); goto clean; } if ((t = objtype(fp, NULL)) == -1) { error("library file corrupted"); goto clean; } if (t != bintype) { error("incompatible library"); goto clean; } newobject(fp, t, OUTLIB); added = 1; } if (!added) break; } clean: free(def); } static int newmember(FILE *fp, char *name, void *data) { int t; int *nmemb = data; if (bintype == -1) { error("an object file is needed before any library"); return 0; } if (*nmemb++ == 0) { if (!strncmp(name, "/", SARNAM) || !strncmp(name, "__.SYMDEF", SARNAM)) { addlib(fp); return 0; } } membname = name; if ((t = objtype(fp, NULL)) == -1) return 1; if (bintype != t) { error("wrong object file format"); return 1; } newobject(fp, t, INLIB); membname = NULL; return 1; } static int newlibrary(FILE *fp) { int nmemb = 0; return formember(fp, newmember, &nmemb); } static FILE * openfile(char *name, char *buffer) { size_t pathlen, len; FILE *fp; char **bp; char libname[FILENAME_MAX]; extern char *syslibs[]; filename = name; membname = NULL; if (name[0] != '-' || name[1] != 'l') { if ((fp = fopen(name, "rb")) == NULL) error(errstr()); return fp; } len = strlen(name+2) + 3; if (len > FILENAME_MAX-1) { error("library name too long"); return NULL; } strcat(strcpy(buffer, "lib"), name+2); filename = buffer; if ((fp = fopen(libname, "rb")) != NULL) return fp; for (bp = syslibs; *bp; ++bp) { pathlen = strlen(*bp); if (pathlen + len > FILENAME_MAX-1) continue; memcpy(libname, *bp, pathlen); memcpy(libname+pathlen+1, buffer, len); buffer[pathlen] = '/'; if ((fp = fopen(buffer, "rb")) != NULL) return fp; } error("not found"); return NULL; } static void load(char *name) { int t; FILE *fp; char buff[FILENAME_MAX]; if ((fp = openfile(name, buff)) == NULL) return; if ((t = objtype(fp, NULL)) != -1) newobject(fp, t, OUTLIB); else if (archive(fp)) newlibrary(fp); else error("bad format"); } /* * Get the list of object files that are going to be linked */ void pass1(int argc, char *argv[]) { char **ap, *cp, *arg; for (ap = argv+1; *ap; ++ap) { if (ap[0][0] != '-') { load(*ap); continue; } for (cp = &ap[0][1]; *cp; ++cp) { switch (*cp) { case 'l': arg = (cp[1]) ? cp+1 : *++ap; load(arg); continue; case 'u': arg = (cp[1]) ? cp+1 : *++ap; undef(arg); continue; } } } if (moreundef()) { listundef(); exit(EXIT_FAILURE); } }