Initial revision

1 files changed, 549 insertions, 0 deletions

diff --git a/ld/ldcref.c b/ld/ldcref.c
new file mode 100644
index 0000000000..96e0d2d9df
--- /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);
+}