| /* ldcref.c -- output a cross reference table |
| Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 |
| Free Software Foundation, Inc. |
| Written by Ian Lance Taylor <ian@cygnus.com> |
| |
| This file is part of GLD, the Gnu Linker. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| |
| /* This file holds routines that manage the cross reference table. |
| The table is used to generate cross reference reports. It is also |
| used to implement the NOCROSSREFS command in the linker script. */ |
| |
| #include "bfd.h" |
| #include "sysdep.h" |
| #include "bfdlink.h" |
| #include "libiberty.h" |
| |
| #include "ld.h" |
| #include "ldmain.h" |
| #include "ldmisc.h" |
| #include "ldexp.h" |
| #include "ldlang.h" |
| |
| /* We keep an instance of this structure for each reference to a |
| symbol from a given object. */ |
| |
| struct cref_ref { |
| /* The next reference. */ |
| struct cref_ref *next; |
| /* The object. */ |
| bfd *abfd; |
| /* True if the symbol is defined. */ |
| unsigned int def : 1; |
| /* True if the symbol is common. */ |
| unsigned int common : 1; |
| /* True if the symbol is undefined. */ |
| unsigned int undef : 1; |
| }; |
| |
| /* We keep a hash table of symbols. Each entry looks like this. */ |
| |
| struct cref_hash_entry { |
| struct bfd_hash_entry root; |
| /* The demangled name. */ |
| char *demangled; |
| /* References to and definitions of this symbol. */ |
| struct cref_ref *refs; |
| }; |
| |
| /* This is what the hash table looks like. */ |
| |
| struct cref_hash_table { |
| struct bfd_hash_table root; |
| }; |
| |
| /* Forward declarations. */ |
| |
| static void output_one_cref (FILE *, struct cref_hash_entry *); |
| static void check_local_sym_xref (lang_input_statement_type *); |
| static bfd_boolean check_nocrossref (struct cref_hash_entry *, void *); |
| static void check_refs (const char *, asection *, bfd *, |
| struct lang_nocrossrefs *); |
| static void check_reloc_refs (bfd *, asection *, void *); |
| |
| /* Look up an entry in the cref hash table. */ |
| |
| #define cref_hash_lookup(table, string, create, copy) \ |
| ((struct cref_hash_entry *) \ |
| bfd_hash_lookup (&(table)->root, (string), (create), (copy))) |
| |
| /* Traverse the cref hash table. */ |
| |
| #define cref_hash_traverse(table, func, info) \ |
| (bfd_hash_traverse \ |
| (&(table)->root, \ |
| (bfd_boolean (*) (struct bfd_hash_entry *, void *)) (func), \ |
| (info))) |
| |
| /* The cref hash table. */ |
| |
| static struct cref_hash_table cref_table; |
| |
| /* Whether the cref hash table has been initialized. */ |
| |
| static bfd_boolean cref_initialized; |
| |
| /* The number of symbols seen so far. */ |
| |
| static size_t cref_symcount; |
| |
| /* Create an entry in a cref hash table. */ |
| |
| static struct bfd_hash_entry * |
| cref_hash_newfunc (struct bfd_hash_entry *entry, |
| struct bfd_hash_table *table, |
| const char *string) |
| { |
| struct cref_hash_entry *ret = (struct cref_hash_entry *) entry; |
| |
| /* Allocate the structure if it has not already been allocated by a |
| subclass. */ |
| if (ret == NULL) |
| ret = ((struct cref_hash_entry *) |
| bfd_hash_allocate (table, sizeof (struct cref_hash_entry))); |
| if (ret == NULL) |
| return NULL; |
| |
| /* Call the allocation method of the superclass. */ |
| ret = ((struct cref_hash_entry *) |
| bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string)); |
| if (ret != NULL) |
| { |
| /* Set local fields. */ |
| ret->demangled = NULL; |
| ret->refs = NULL; |
| |
| /* Keep a count of the number of entries created in the hash |
| table. */ |
| ++cref_symcount; |
| } |
| |
| return &ret->root; |
| } |
| |
| /* Add a symbol to the cref hash table. This is called for every |
| global symbol that is seen during the link. */ |
| |
| void |
| add_cref (const char *name, |
| bfd *abfd, |
| asection *section, |
| bfd_vma value ATTRIBUTE_UNUSED) |
| { |
| struct cref_hash_entry *h; |
| struct cref_ref *r; |
| |
| if (! cref_initialized) |
| { |
| if (! bfd_hash_table_init (&cref_table.root, cref_hash_newfunc)) |
| einfo (_("%X%P: bfd_hash_table_init of cref table failed: %E\n")); |
| cref_initialized = TRUE; |
| } |
| |
| h = cref_hash_lookup (&cref_table, name, TRUE, FALSE); |
| if (h == NULL) |
| einfo (_("%X%P: cref_hash_lookup failed: %E\n")); |
| |
| for (r = h->refs; r != NULL; r = r->next) |
| if (r->abfd == abfd) |
| break; |
| |
| if (r == NULL) |
| { |
| r = xmalloc (sizeof *r); |
| r->next = h->refs; |
| h->refs = r; |
| r->abfd = abfd; |
| r->def = FALSE; |
| r->common = FALSE; |
| r->undef = FALSE; |
| } |
| |
| if (bfd_is_und_section (section)) |
| r->undef = TRUE; |
| else if (bfd_is_com_section (section)) |
| r->common = TRUE; |
| else |
| r->def = TRUE; |
| } |
| |
| /* Copy the addresses of the hash table entries into an array. This |
| is called via cref_hash_traverse. We also fill in the demangled |
| name. */ |
| |
| static bfd_boolean |
| cref_fill_array (struct cref_hash_entry *h, void *data) |
| { |
| struct cref_hash_entry ***pph = data; |
| |
| ASSERT (h->demangled == NULL); |
| h->demangled = demangle (h->root.string); |
| |
| **pph = h; |
| |
| ++*pph; |
| |
| return TRUE; |
| } |
| |
| /* Sort an array of cref hash table entries by name. */ |
| |
| static int |
| cref_sort_array (const void *a1, const void *a2) |
| { |
| const struct cref_hash_entry * const *p1 = a1; |
| const struct cref_hash_entry * const *p2 = a2; |
| |
| return strcmp ((*p1)->demangled, (*p2)->demangled); |
| } |
| |
| /* Write out the cref table. */ |
| |
| #define FILECOL (50) |
| |
| void |
| output_cref (FILE *fp) |
| { |
| int len; |
| struct cref_hash_entry **csyms, **csym_fill, **csym, **csym_end; |
| const char *msg; |
| |
| fprintf (fp, _("\nCross Reference Table\n\n")); |
| msg = _("Symbol"); |
| fprintf (fp, "%s", msg); |
| len = strlen (msg); |
| while (len < FILECOL) |
| { |
| putc (' ', fp); |
| ++len; |
| } |
| fprintf (fp, _("File\n")); |
| |
| if (! cref_initialized) |
| { |
| fprintf (fp, _("No symbols\n")); |
| return; |
| } |
| |
| csyms = xmalloc (cref_symcount * sizeof (*csyms)); |
| |
| csym_fill = csyms; |
| cref_hash_traverse (&cref_table, cref_fill_array, &csym_fill); |
| ASSERT ((size_t) (csym_fill - csyms) == cref_symcount); |
| |
| qsort (csyms, cref_symcount, sizeof (*csyms), cref_sort_array); |
| |
| csym_end = csyms + cref_symcount; |
| for (csym = csyms; csym < csym_end; csym++) |
| output_one_cref (fp, *csym); |
| } |
| |
| /* Output one entry in the cross reference table. */ |
| |
| static void |
| output_one_cref (FILE *fp, struct cref_hash_entry *h) |
| { |
| int len; |
| struct bfd_link_hash_entry *hl; |
| struct cref_ref *r; |
| |
| hl = bfd_link_hash_lookup (link_info.hash, h->root.string, FALSE, |
| FALSE, TRUE); |
| if (hl == NULL) |
| einfo ("%P: symbol `%T' missing from main hash table\n", |
| h->root.string); |
| else |
| { |
| /* If this symbol is defined in a dynamic object but never |
| referenced by a normal object, then don't print it. */ |
| if (hl->type == bfd_link_hash_defined) |
| { |
| if (hl->u.def.section->output_section == NULL) |
| return; |
| if (hl->u.def.section->owner != NULL |
| && (hl->u.def.section->owner->flags & DYNAMIC) != 0) |
| { |
| for (r = h->refs; r != NULL; r = r->next) |
| if ((r->abfd->flags & DYNAMIC) == 0) |
| break; |
| if (r == NULL) |
| return; |
| } |
| } |
| } |
| |
| fprintf (fp, "%s ", h->demangled); |
| len = strlen (h->demangled) + 1; |
| |
| for (r = h->refs; r != NULL; r = r->next) |
| { |
| if (r->def) |
| { |
| while (len < FILECOL) |
| { |
| putc (' ', fp); |
| ++len; |
| } |
| lfinfo (fp, "%B\n", r->abfd); |
| len = 0; |
| } |
| } |
| |
| for (r = h->refs; r != NULL; r = r->next) |
| { |
| if (! r->def) |
| { |
| while (len < FILECOL) |
| { |
| putc (' ', fp); |
| ++len; |
| } |
| lfinfo (fp, "%B\n", r->abfd); |
| len = 0; |
| } |
| } |
| |
| ASSERT (len == 0); |
| } |
| |
| /* Check for prohibited cross references. */ |
| |
| void |
| check_nocrossrefs (void) |
| { |
| if (! cref_initialized) |
| return; |
| |
| cref_hash_traverse (&cref_table, check_nocrossref, NULL); |
| |
| lang_for_each_file (check_local_sym_xref); |
| } |
| |
| /* Check for prohibited cross references to local and section symbols. */ |
| |
| static void |
| check_local_sym_xref (lang_input_statement_type *statement) |
| { |
| bfd *abfd; |
| lang_input_statement_type *li; |
| asymbol **asymbols, **syms; |
| |
| abfd = statement->the_bfd; |
| if (abfd == NULL) |
| return; |
| |
| li = abfd->usrdata; |
| if (li != NULL && li->asymbols != NULL) |
| asymbols = li->asymbols; |
| else |
| { |
| long symsize; |
| long symbol_count; |
| |
| symsize = bfd_get_symtab_upper_bound (abfd); |
| if (symsize < 0) |
| einfo (_("%B%F: could not read symbols; %E\n"), abfd); |
| asymbols = xmalloc (symsize); |
| symbol_count = bfd_canonicalize_symtab (abfd, asymbols); |
| if (symbol_count < 0) |
| einfo (_("%B%F: could not read symbols: %E\n"), abfd); |
| if (li != NULL) |
| { |
| li->asymbols = asymbols; |
| li->symbol_count = symbol_count; |
| } |
| } |
| |
| for (syms = asymbols; *syms; ++syms) |
| { |
| asymbol *sym = *syms; |
| if (sym->flags & (BSF_GLOBAL | BSF_WARNING | BSF_INDIRECT | BSF_FILE)) |
| continue; |
| if ((sym->flags & (BSF_LOCAL | BSF_SECTION_SYM)) != 0 |
| && sym->section->output_section != NULL) |
| { |
| const char *outsecname, *symname; |
| struct lang_nocrossrefs *ncrs; |
| struct lang_nocrossref *ncr; |
| |
| outsecname = sym->section->output_section->name; |
| symname = NULL; |
| if ((sym->flags & BSF_SECTION_SYM) == 0) |
| symname = sym->name; |
| for (ncrs = nocrossref_list; ncrs != NULL; ncrs = ncrs->next) |
| for (ncr = ncrs->list; ncr != NULL; ncr = ncr->next) |
| if (strcmp (ncr->name, outsecname) == 0) |
| check_refs (symname, sym->section, abfd, ncrs); |
| } |
| } |
| |
| if (li == NULL) |
| free (asymbols); |
| } |
| |
| /* Check one symbol to see if it is a prohibited cross reference. */ |
| |
| static bfd_boolean |
| check_nocrossref (struct cref_hash_entry *h, void *ignore ATTRIBUTE_UNUSED) |
| { |
| struct bfd_link_hash_entry *hl; |
| asection *defsec; |
| const char *defsecname; |
| struct lang_nocrossrefs *ncrs; |
| struct lang_nocrossref *ncr; |
| struct cref_ref *ref; |
| |
| hl = bfd_link_hash_lookup (link_info.hash, h->root.string, FALSE, |
| FALSE, TRUE); |
| if (hl == NULL) |
| { |
| einfo (_("%P: symbol `%T' missing from main hash table\n"), |
| h->root.string); |
| return TRUE; |
| } |
| |
| if (hl->type != bfd_link_hash_defined |
| && hl->type != bfd_link_hash_defweak) |
| return TRUE; |
| |
| defsec = hl->u.def.section->output_section; |
| if (defsec == NULL) |
| return TRUE; |
| defsecname = bfd_get_section_name (defsec->owner, defsec); |
| |
| for (ncrs = nocrossref_list; ncrs != NULL; ncrs = ncrs->next) |
| for (ncr = ncrs->list; ncr != NULL; ncr = ncr->next) |
| if (strcmp (ncr->name, defsecname) == 0) |
| for (ref = h->refs; ref != NULL; ref = ref->next) |
| check_refs (hl->root.string, hl->u.def.section, ref->abfd, ncrs); |
| |
| return TRUE; |
| } |
| |
| /* The struct is used to pass information from check_refs to |
| check_reloc_refs through bfd_map_over_sections. */ |
| |
| struct check_refs_info { |
| const char *sym_name; |
| asection *defsec; |
| struct lang_nocrossrefs *ncrs; |
| asymbol **asymbols; |
| }; |
| |
| /* This function is called for each symbol defined in a section which |
| prohibits cross references. We need to look through all references |
| to this symbol, and ensure that the references are not from |
| prohibited sections. */ |
| |
| static void |
| check_refs (const char *name, |
| asection *sec, |
| bfd *abfd, |
| struct lang_nocrossrefs *ncrs) |
| { |
| lang_input_statement_type *li; |
| asymbol **asymbols; |
| struct check_refs_info info; |
| |
| /* We need to look through the relocations for this BFD, to see |
| if any of the relocations which refer to this symbol are from |
| a prohibited section. Note that we need to do this even for |
| the BFD in which the symbol is defined, since even a single |
| BFD might contain a prohibited cross reference. */ |
| |
| li = abfd->usrdata; |
| if (li != NULL && li->asymbols != NULL) |
| asymbols = li->asymbols; |
| else |
| { |
| long symsize; |
| long symbol_count; |
| |
| symsize = bfd_get_symtab_upper_bound (abfd); |
| if (symsize < 0) |
| einfo (_("%B%F: could not read symbols; %E\n"), abfd); |
| asymbols = xmalloc (symsize); |
| symbol_count = bfd_canonicalize_symtab (abfd, asymbols); |
| if (symbol_count < 0) |
| einfo (_("%B%F: could not read symbols: %E\n"), abfd); |
| if (li != NULL) |
| { |
| li->asymbols = asymbols; |
| li->symbol_count = symbol_count; |
| } |
| } |
| |
| info.sym_name = name; |
| info.defsec = sec; |
| info.ncrs = ncrs; |
| info.asymbols = asymbols; |
| bfd_map_over_sections (abfd, check_reloc_refs, &info); |
| |
| if (li == NULL) |
| free (asymbols); |
| } |
| |
| /* This is called via bfd_map_over_sections. INFO->SYM_NAME is a symbol |
| defined in INFO->DEFSECNAME. If this section maps into any of the |
| sections listed in INFO->NCRS, other than INFO->DEFSECNAME, then we |
| look through the relocations. If any of the relocations are to |
| INFO->SYM_NAME, then we report a prohibited cross reference error. */ |
| |
| static void |
| check_reloc_refs (bfd *abfd, asection *sec, void *iarg) |
| { |
| struct check_refs_info *info = iarg; |
| asection *outsec; |
| const char *outsecname; |
| asection *outdefsec; |
| const char *outdefsecname; |
| struct lang_nocrossref *ncr; |
| const char *symname; |
| long relsize; |
| arelent **relpp; |
| long relcount; |
| arelent **p, **pend; |
| |
| outsec = sec->output_section; |
| outsecname = bfd_get_section_name (outsec->owner, outsec); |
| |
| outdefsec = info->defsec->output_section; |
| outdefsecname = bfd_get_section_name (outdefsec->owner, outdefsec); |
| |
| /* The section where the symbol is defined is permitted. */ |
| if (strcmp (outsecname, outdefsecname) == 0) |
| return; |
| |
| for (ncr = info->ncrs->list; ncr != NULL; ncr = ncr->next) |
| if (strcmp (outsecname, ncr->name) == 0) |
| break; |
| |
| if (ncr == NULL) |
| return; |
| |
| /* This section is one for which cross references are prohibited. |
| Look through the relocations, and see if any of them are to |
| INFO->SYM_NAME. If INFO->SYMNAME is NULL, check for relocations |
| against the section symbol. */ |
| |
| symname = info->sym_name; |
| |
| relsize = bfd_get_reloc_upper_bound (abfd, sec); |
| if (relsize < 0) |
| einfo (_("%B%F: could not read relocs: %E\n"), abfd); |
| if (relsize == 0) |
| return; |
| |
| relpp = xmalloc (relsize); |
| relcount = bfd_canonicalize_reloc (abfd, sec, relpp, info->asymbols); |
| if (relcount < 0) |
| einfo (_("%B%F: could not read relocs: %E\n"), abfd); |
| |
| p = relpp; |
| pend = p + relcount; |
| for (; p < pend && *p != NULL; p++) |
| { |
| arelent *q = *p; |
| |
| if (q->sym_ptr_ptr != NULL |
| && *q->sym_ptr_ptr != NULL |
| && (symname != NULL |
| ? strcmp (bfd_asymbol_name (*q->sym_ptr_ptr), symname) == 0 |
| : (((*q->sym_ptr_ptr)->flags & BSF_SECTION_SYM) != 0 |
| && bfd_get_section (*q->sym_ptr_ptr) == info->defsec))) |
| { |
| /* We found a reloc for the symbol. The symbol is defined |
| in OUTSECNAME. This reloc is from a section which is |
| mapped into a section from which references to OUTSECNAME |
| are prohibited. We must report an error. */ |
| einfo (_("%X%C: prohibited cross reference from %s to `%T' in %s\n"), |
| abfd, sec, q->address, outsecname, |
| bfd_asymbol_name (*q->sym_ptr_ptr), outdefsecname); |
| } |
| } |
| |
| free (relpp); |
| } |