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Diffstat (limited to 'ld/ldcref.c')
-rw-r--r-- | ld/ldcref.c | 549 |
1 files changed, 549 insertions, 0 deletions
diff --git a/ld/ldcref.c b/ld/ldcref.c new file mode 100644 index 0000000..96e0d2d --- /dev/null +++ b/ld/ldcref.c @@ -0,0 +1,549 @@ +/* ldcref.c -- output a cross reference table + Copyright (C) 1996, 1997, 1998 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; +}; + +/* Local functions. */ + +static struct bfd_hash_entry *cref_hash_newfunc + PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *)); +static boolean cref_fill_array PARAMS ((struct cref_hash_entry *, PTR)); +static int cref_sort_array PARAMS ((const PTR, const PTR)); +static void output_one_cref PARAMS ((FILE *, struct cref_hash_entry *)); +static boolean check_nocrossref PARAMS ((struct cref_hash_entry *, PTR)); +static void check_refs + PARAMS ((struct cref_hash_entry *, struct bfd_link_hash_entry *, + struct lang_nocrossrefs *)); +static void check_reloc_refs PARAMS ((bfd *, asection *, PTR)); + +/* 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, \ + (boolean (*) PARAMS ((struct bfd_hash_entry *, PTR))) (func), \ + (info))) + +/* The cref hash table. */ + +static struct cref_hash_table cref_table; + +/* Whether the cref hash table has been initialized. */ + +static 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 (entry, table, string) + 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 (struct bfd_hash_entry *) ret; + + /* 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 (struct bfd_hash_entry *) ret; +} + +/* Add a symbol to the cref hash table. This is called for every + symbol that is seen during the link. */ + +/*ARGSUSED*/ +void +add_cref (name, abfd, section, value) + const char *name; + bfd *abfd; + asection *section; + bfd_vma value; +{ + 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 = (struct cref_ref *) 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 boolean +cref_fill_array (h, data) + struct cref_hash_entry *h; + PTR data; +{ + struct cref_hash_entry ***pph = (struct cref_hash_entry ***) 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 (a1, a2) + const PTR a1; + const PTR a2; +{ + const struct cref_hash_entry **p1 = (const struct cref_hash_entry **) a1; + const struct cref_hash_entry **p2 = (const struct cref_hash_entry **) a2; + + return strcmp ((*p1)->demangled, (*p2)->demangled); +} + +/* Write out the cref table. */ + +#define FILECOL (50) + +void +output_cref (fp) + 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, 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 (fp, h) + 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 () +{ + if (! cref_initialized) + return; + + cref_hash_traverse (&cref_table, check_nocrossref, (PTR) NULL); +} + +/* Check one symbol to see if it is a prohibited cross reference. */ + +/*ARGSUSED*/ +static boolean +check_nocrossref (h, ignore) + struct cref_hash_entry *h; + PTR ignore; +{ + struct bfd_link_hash_entry *hl; + asection *defsec; + const char *defsecname; + struct lang_nocrossrefs *ncrs; + struct lang_nocrossref *ncr; + + 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) + check_refs (h, hl, 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 +{ + struct cref_hash_entry *h; + asection *defsec; + struct lang_nocrossrefs *ncrs; + asymbol **asymbols; + boolean same; +}; + +/* 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 (h, hl, ncrs) + struct cref_hash_entry *h; + struct bfd_link_hash_entry *hl; + struct lang_nocrossrefs *ncrs; +{ + struct cref_ref *ref; + + for (ref = h->refs; ref != NULL; ref = ref->next) + { + 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; for this + case, we set the SAME field in INFO, which will cause + CHECK_RELOCS_REFS to check for relocations against the + section as well as against the symbol. */ + + li = (lang_input_statement_type *) ref->abfd->usrdata; + if (li != NULL && li->asymbols != NULL) + asymbols = li->asymbols; + else + { + long symsize; + long symbol_count; + + symsize = bfd_get_symtab_upper_bound (ref->abfd); + if (symsize < 0) + einfo (_("%B%F: could not read symbols; %E\n"), ref->abfd); + asymbols = (asymbol **) xmalloc (symsize); + symbol_count = bfd_canonicalize_symtab (ref->abfd, asymbols); + if (symbol_count < 0) + einfo (_("%B%F: could not read symbols: %E\n"), ref->abfd); + if (li != NULL) + { + li->asymbols = asymbols; + li->symbol_count = symbol_count; + } + } + + info.h = h; + info.defsec = hl->u.def.section; + info.ncrs = ncrs; + info.asymbols = asymbols; + if (ref->abfd == hl->u.def.section->owner) + info.same = true; + else + info.same = false; + bfd_map_over_sections (ref->abfd, check_reloc_refs, (PTR) &info); + + if (li == NULL) + free (asymbols); + } +} + +/* This is called via bfd_map_over_sections. INFO->H 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->H, then we report a prohibited cross reference error. */ + +static void +check_reloc_refs (abfd, sec, iarg) + bfd *abfd; + asection *sec; + PTR 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; + 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->H. */ + + symname = info->h->root.string; + + 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 = (arelent **) 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 + && (strcmp (bfd_asymbol_name (*q->sym_ptr_ptr), symname) == 0 + || (info->same + && 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); +} |