| /* ldcref.c -- output a cross reference table |
| Copyright (C) 1996-2024 Free Software Foundation, Inc. |
| Written by Ian Lance Taylor <ian@cygnus.com> |
| |
| This file is part of the GNU Binutils. |
| |
| 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 3 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., 51 Franklin Street - Fifth Floor, Boston, |
| MA 02110-1301, 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 "sysdep.h" |
| #include "bfd.h" |
| #include "bfdlink.h" |
| #include "ctf-api.h" |
| #include "libiberty.h" |
| #include "demangle.h" |
| #include "objalloc.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. */ |
| const 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 bool check_nocrossref (struct cref_hash_entry *, void *); |
| static void check_refs (const char *, bool, 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, \ |
| (bool (*) (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 bool cref_initialized; |
| |
| /* The number of symbols seen so far. */ |
| |
| static size_t cref_symcount; |
| |
| /* Used to take a snapshot of the cref hash table when starting to |
| add syms from an as-needed library. */ |
| static struct bfd_hash_entry **old_table; |
| static unsigned int old_size; |
| static unsigned int old_count; |
| static void *old_tab; |
| static void *alloc_mark; |
| static size_t tabsize, entsize, refsize; |
| static size_t old_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, |
| sizeof (struct cref_hash_entry))) |
| 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 = (struct cref_ref *) bfd_hash_allocate (&cref_table.root, sizeof *r); |
| if (r == NULL) |
| einfo (_("%X%P: cref alloc failed: %E\n")); |
| 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; |
| } |
| |
| /* Called before loading an as-needed library to take a snapshot of |
| the cref hash table, and after we have loaded or found that the |
| library was not needed. */ |
| |
| bool |
| handle_asneeded_cref (bfd *abfd ATTRIBUTE_UNUSED, |
| enum notice_asneeded_action act) |
| { |
| unsigned int i; |
| |
| if (!cref_initialized) |
| return true; |
| |
| if (act == notice_as_needed) |
| { |
| char *old_ent, *old_ref; |
| |
| for (i = 0; i < cref_table.root.size; i++) |
| { |
| struct bfd_hash_entry *p; |
| struct cref_hash_entry *c; |
| struct cref_ref *r; |
| |
| for (p = cref_table.root.table[i]; p != NULL; p = p->next) |
| { |
| entsize += cref_table.root.entsize; |
| c = (struct cref_hash_entry *) p; |
| for (r = c->refs; r != NULL; r = r->next) |
| refsize += sizeof (struct cref_ref); |
| } |
| } |
| |
| tabsize = cref_table.root.size * sizeof (struct bfd_hash_entry *); |
| old_tab = xmalloc (tabsize + entsize + refsize); |
| |
| alloc_mark = bfd_hash_allocate (&cref_table.root, 1); |
| if (alloc_mark == NULL) |
| return false; |
| |
| memcpy (old_tab, cref_table.root.table, tabsize); |
| old_ent = (char *) old_tab + tabsize; |
| old_ref = (char *) old_ent + entsize; |
| old_table = cref_table.root.table; |
| old_size = cref_table.root.size; |
| old_count = cref_table.root.count; |
| old_symcount = cref_symcount; |
| |
| for (i = 0; i < cref_table.root.size; i++) |
| { |
| struct bfd_hash_entry *p; |
| struct cref_hash_entry *c; |
| struct cref_ref *r; |
| |
| for (p = cref_table.root.table[i]; p != NULL; p = p->next) |
| { |
| memcpy (old_ent, p, cref_table.root.entsize); |
| old_ent = (char *) old_ent + cref_table.root.entsize; |
| c = (struct cref_hash_entry *) p; |
| for (r = c->refs; r != NULL; r = r->next) |
| { |
| memcpy (old_ref, r, sizeof (struct cref_ref)); |
| old_ref = (char *) old_ref + sizeof (struct cref_ref); |
| } |
| } |
| } |
| return true; |
| } |
| |
| if (act == notice_not_needed) |
| { |
| char *old_ent, *old_ref; |
| |
| if (old_tab == NULL) |
| { |
| /* The only way old_tab can be NULL is if the cref hash table |
| had not been initialised when notice_as_needed. */ |
| bfd_hash_table_free (&cref_table.root); |
| cref_initialized = false; |
| return true; |
| } |
| |
| old_ent = (char *) old_tab + tabsize; |
| old_ref = (char *) old_ent + entsize; |
| cref_table.root.table = old_table; |
| cref_table.root.size = old_size; |
| cref_table.root.count = old_count; |
| memcpy (cref_table.root.table, old_tab, tabsize); |
| cref_symcount = old_symcount; |
| |
| for (i = 0; i < cref_table.root.size; i++) |
| { |
| struct bfd_hash_entry *p; |
| struct cref_hash_entry *c; |
| struct cref_ref *r; |
| |
| for (p = cref_table.root.table[i]; p != NULL; p = p->next) |
| { |
| memcpy (p, old_ent, cref_table.root.entsize); |
| old_ent = (char *) old_ent + cref_table.root.entsize; |
| c = (struct cref_hash_entry *) p; |
| for (r = c->refs; r != NULL; r = r->next) |
| { |
| memcpy (r, old_ref, sizeof (struct cref_ref)); |
| old_ref = (char *) old_ref + sizeof (struct cref_ref); |
| } |
| } |
| } |
| |
| objalloc_free_block ((struct objalloc *) cref_table.root.memory, |
| alloc_mark); |
| } |
| else if (act != notice_needed) |
| return false; |
| |
| free (old_tab); |
| old_tab = NULL; |
| return 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 bool |
| cref_fill_array (struct cref_hash_entry *h, void *data) |
| { |
| struct cref_hash_entry ***pph = (struct cref_hash_entry ***) data; |
| |
| ASSERT (h->demangled == NULL); |
| h->demangled = bfd_demangle (link_info.output_bfd, h->root.string, |
| DMGL_ANSI | DMGL_PARAMS); |
| if (h->demangled == NULL) |
| h->demangled = 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 |
| = (const struct cref_hash_entry *const *) a1; |
| const struct cref_hash_entry *const *p2 |
| = (const struct cref_hash_entry *const *) a2; |
| |
| if (demangling) |
| return strcmp ((*p1)->demangled, (*p2)->demangled); |
| else |
| return strcmp ((*p1)->root.string, (*p2)->root.string); |
| } |
| |
| /* 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 = (struct cref_hash_entry **) 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 `%pT' 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; |
| } |
| } |
| } |
| |
| if (demangling) |
| { |
| fprintf (fp, "%s ", h->demangled); |
| len = strlen (h->demangled) + 1; |
| } |
| else |
| { |
| fprintf (fp, "%s ", h->root.string); |
| len = strlen (h->root.string) + 1; |
| } |
| |
| for (r = h->refs; r != NULL; r = r->next) |
| { |
| if (r->def) |
| { |
| while (len < FILECOL) |
| { |
| putc (' ', fp); |
| ++len; |
| } |
| lfinfo (fp, "%pB\n", r->abfd); |
| len = 0; |
| } |
| } |
| |
| for (r = h->refs; r != NULL; r = r->next) |
| { |
| if (r->common) |
| { |
| while (len < FILECOL) |
| { |
| putc (' ', fp); |
| ++len; |
| } |
| lfinfo (fp, "%pB\n", r->abfd); |
| len = 0; |
| } |
| } |
| |
| for (r = h->refs; r != NULL; r = r->next) |
| { |
| if (!r->def && !r->common) |
| { |
| while (len < FILECOL) |
| { |
| putc (' ', fp); |
| ++len; |
| } |
| lfinfo (fp, "%pB\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; |
| asymbol **syms; |
| |
| abfd = statement->the_bfd; |
| if (abfd == NULL) |
| return; |
| |
| if (!bfd_generic_link_read_symbols (abfd)) |
| einfo (_("%F%P: %pB: could not read symbols: %E\n"), abfd); |
| |
| for (syms = bfd_get_outsymbols (abfd); *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, false, sym->section, abfd, ncrs); |
| /* The NOCROSSREFS_TO command only checks symbols defined in |
| the first section in the list. */ |
| if (ncrs->onlyfirst) |
| break; |
| } |
| } |
| } |
| } |
| |
| /* Check one symbol to see if it is a prohibited cross reference. */ |
| |
| static bool |
| 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 `%pT' 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_section_name (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, true, hl->u.def.section, |
| ref->abfd, ncrs); |
| /* The NOCROSSREFS_TO command only checks symbols defined in the first |
| section in the list. */ |
| if (ncrs->onlyfirst) |
| break; |
| } |
| |
| 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; |
| bool global; |
| }; |
| |
| /* 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, |
| bool global, |
| asection *sec, |
| bfd *abfd, |
| struct lang_nocrossrefs *ncrs) |
| { |
| 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. */ |
| |
| if (!bfd_generic_link_read_symbols (abfd)) |
| einfo (_("%F%P: %pB: could not read symbols: %E\n"), abfd); |
| |
| info.sym_name = name; |
| info.global = global; |
| info.defsec = sec; |
| info.ncrs = ncrs; |
| info.asymbols = bfd_get_outsymbols (abfd); |
| bfd_map_over_sections (abfd, check_reloc_refs, &info); |
| } |
| |
| /* 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 = (struct check_refs_info *) iarg; |
| asection *outsec; |
| const char *outsecname; |
| asection *outdefsec; |
| const char *outdefsecname; |
| struct lang_nocrossref *ncr; |
| const char *symname; |
| bool global; |
| long relsize; |
| arelent **relpp; |
| long relcount; |
| arelent **p, **pend; |
| |
| outsec = sec->output_section; |
| outsecname = bfd_section_name (outsec); |
| |
| outdefsec = info->defsec->output_section; |
| outdefsecname = bfd_section_name (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. If INFO->GLOBAL is TRUE, the |
| definition is global, check for relocations against the global |
| symbols. Otherwise check for relocations against the local and |
| section symbols. */ |
| |
| symname = info->sym_name; |
| global = info->global; |
| |
| relsize = bfd_get_reloc_upper_bound (abfd, sec); |
| if (relsize < 0) |
| einfo (_("%F%P: %pB: could not read relocs: %E\n"), abfd); |
| if (relsize == 0) |
| return; |
| |
| relpp = (arelent **) xmalloc (relsize); |
| relcount = bfd_canonicalize_reloc (abfd, sec, relpp, info->asymbols); |
| if (relcount < 0) |
| einfo (_("%F%P: %pB: 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 |
| && ((global |
| && (bfd_is_und_section (bfd_asymbol_section (*q->sym_ptr_ptr)) |
| || bfd_is_com_section (bfd_asymbol_section (*q->sym_ptr_ptr)) |
| || ((*q->sym_ptr_ptr)->flags & (BSF_GLOBAL |
| | BSF_WEAK)) != 0)) |
| || (!global |
| && ((*q->sym_ptr_ptr)->flags & (BSF_LOCAL |
| | BSF_SECTION_SYM)) != 0 |
| && bfd_asymbol_section (*q->sym_ptr_ptr) == info->defsec)) |
| && (symname != NULL |
| ? strcmp (bfd_asymbol_name (*q->sym_ptr_ptr), symname) == 0 |
| : ((*q->sym_ptr_ptr)->flags & BSF_SECTION_SYM) != 0)) |
| { |
| /* 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%P: %H: prohibited cross reference from %s to `%pT' in %s\n"), |
| abfd, sec, q->address, outsecname, |
| bfd_asymbol_name (*q->sym_ptr_ptr), outdefsecname); |
| } |
| } |
| |
| free (relpp); |
| } |