aboutsummaryrefslogtreecommitdiff
path: root/ld/ldcref.c
diff options
context:
space:
mode:
Diffstat (limited to 'ld/ldcref.c')
-rw-r--r--ld/ldcref.c549
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);
+}