4 files changed, 183 insertions, 121 deletions

diff --git a/bfd/bfd.c b/bfd/bfd.c
index 8fd86f6..ace2f67 100644
--- a/bfd/bfd.c
+++ b/bfd/bfd.c
@@ -1565,10 +1565,91 @@ err_sprintf (void *stream, const char *fmt, ...)
   return total;
 }
 
-/* Communicate the bfd processed by bfd_check_format_matches to the
-   error handling function error_handler_sprintf.  */
+/*
+INTERNAL
+.{* Cached _bfd_check_format messages are put in this.  *}
+.struct per_xvec_message
+.{
+.  struct per_xvec_message *next;
+.  char message[];
+.};
+.
+.{* A list of per_xvec_message objects.  The targ field indicates
+.   which xvec this list holds; PER_XVEC_NO_TARGET is only set for the
+.   root of the list and indicates that the entry isn't yet used.  The
+.   abfd field is only needed in the root entry of the list.  *}
+.struct per_xvec_messages
+.{
+.  bfd *abfd;
+.  const bfd_target *targ;
+.  struct per_xvec_message *messages;
+.  struct per_xvec_messages *next;
+.};
+.
+.#define PER_XVEC_NO_TARGET ((const bfd_target *) -1)
+*/
+
+/* Helper function to find or allocate the correct per-xvec object
+   when emitting a message.  */
+
+static struct per_xvec_message *
+_bfd_per_xvec_warn (struct per_xvec_messages *messages, size_t alloc)
+{
+  const bfd_target *targ = messages->abfd->xvec;
+
+  struct per_xvec_messages *prev = NULL;
+  struct per_xvec_messages *iter = messages;
+
+  if (iter->targ == PER_XVEC_NO_TARGET)
+    iter->targ = targ;
+  else
+    for (; iter != NULL; iter = iter->next)
+      {
+	if (iter->targ == targ)
+	  break;
+	prev = iter;
+      }
+
+  if (iter == NULL)
+    {
+      iter = bfd_malloc (sizeof (*iter));
+      if (iter == NULL)
+	return NULL;
+      iter->abfd = messages->abfd;
+      iter->targ = targ;
+      iter->messages = NULL;
+      iter->next = NULL;
+      prev->next = iter;
+    }
+
+  struct per_xvec_message **m = &iter->messages;
+  int count = 0;
+  while (*m)
+    {
+      m = &(*m)->next;
+      count++;
+    }
+  /* Anti-fuzzer measure.  Don't cache more than 5 messages.  */
+  if (count < 5)
+    {
+      *m = bfd_malloc (sizeof (**m) + alloc);
+      if (*m != NULL)
+	(*m)->next = NULL;
+    }
+  return *m;
+}
 
-static bfd *error_handler_bfd;
+/* Communicate the error-message container processed by
+   bfd_check_format_matches to the error handling function
+   error_handler_sprintf.  When non-NULL, _bfd_error_handler will call
+   error_handler_sprintf; when NULL, _bfd_error_internal will be used
+   instead.  */
+
+static TLS struct per_xvec_messages *error_handler_messages;
+
+/* A special value for error_handler_messages that indicates that the
+   error should simply be ignored.  */
+#define IGNORE_ERROR_MESSAGES ((struct per_xvec_messages *) -1)
 
 /* An error handler that prints to a string, then dups that string to
    a per-xvec cache.  */
@@ -1585,12 +1666,12 @@ error_handler_sprintf (const char *fmt, va_list ap)
   _bfd_print (err_sprintf, &error_stream, fmt, ap);
 
   size_t len = error_stream.ptr - error_buf;
-  struct per_xvec_message **warn
-    = _bfd_per_xvec_warn (error_handler_bfd->xvec, len + 1);
-  if (*warn)
+  struct per_xvec_message *warn
+    = _bfd_per_xvec_warn (error_handler_messages, len + 1);
+  if (warn)
     {
-      memcpy ((*warn)->message, error_buf, len);
-      (*warn)->message[len] = 0;
+      memcpy (warn->message, error_buf, len);
+      warn->message[len] = 0;
     }
 }
 
@@ -1628,7 +1709,14 @@ _bfd_error_handler (const char *fmt, ...)
   va_list ap;
 
   va_start (ap, fmt);
-  _bfd_error_internal (fmt, ap);
+  if (error_handler_messages == IGNORE_ERROR_MESSAGES)
+    {
+      /* Nothing.  */
+    }
+  else if (error_handler_messages != NULL)
+    error_handler_sprintf (fmt, ap);
+  else
+    _bfd_error_internal (fmt, ap);
   va_end (ap);
 }
 
@@ -1659,18 +1747,42 @@ INTERNAL_FUNCTION
 	_bfd_set_error_handler_caching
 
 SYNOPSIS
-	bfd_error_handler_type _bfd_set_error_handler_caching (bfd *);
+	struct per_xvec_messages *_bfd_set_error_handler_caching (struct per_xvec_messages *);
 
 DESCRIPTION
 	Set the BFD error handler function to one that stores messages
-	to the per_xvec_warn array.  Returns the previous function.
+	to the per_xvec_messages object.  Returns the previous object
+	to which messages are stored.  Note that two sequential calls
+	to this with a non-NULL argument will cause output to be
+	dropped, rather than gathered.
 */
 
-bfd_error_handler_type
-_bfd_set_error_handler_caching (bfd *abfd)
+struct per_xvec_messages *
+_bfd_set_error_handler_caching (struct per_xvec_messages *messages)
+{
+  struct per_xvec_messages *old = error_handler_messages;
+  if (old == NULL)
+    error_handler_messages = messages;
+  else
+    error_handler_messages = IGNORE_ERROR_MESSAGES;
+  return old;
+}
+
+/*
+INTERNAL_FUNCTION
+	_bfd_restore_error_handler_caching
+
+SYNOPSIS
+	void _bfd_restore_error_handler_caching (struct per_xvec_messages *);
+
+DESCRIPTION
+	Reset the BFD error handler object to an earlier value.
+*/
+
+void
+_bfd_restore_error_handler_caching (struct per_xvec_messages *old)
 {
-  error_handler_bfd = abfd;
-  return bfd_set_error_handler (error_handler_sprintf);
+  error_handler_messages = old;
 }
 
 /*
diff --git a/bfd/format.c b/bfd/format.c
index 6d95683..2a700ba 100644
--- a/bfd/format.c
+++ b/bfd/format.c
@@ -272,10 +272,34 @@ clear_warnmsg (struct per_xvec_message **list)
   *list = NULL;
 }
 
+/* Free all the storage in LIST.  Note that the first element of LIST
+   is special and is assumed to be stack-allocated.  TARG is used for
+   re-issuing warning messages.  If TARG is PER_XVEC_NO_TARGET, then
+   it acts like a sort of wildcard -- messages are only reissued if
+   they are all associated with a single BFD target, regardless of
+   which one it is.  If TARG is anything else, then only messages
+   associated with TARG are emitted.  */
+
 static void
-null_error_handler (const char *fmt ATTRIBUTE_UNUSED,
-		    va_list ap ATTRIBUTE_UNUSED)
+print_and_clear_messages (struct per_xvec_messages *list,
+			  const bfd_target *targ)
 {
+  struct per_xvec_messages *iter = list;
+
+  if (targ == PER_XVEC_NO_TARGET && list->next == NULL)
+    print_warnmsg (&list->messages);
+
+  while (iter != NULL)
+    {
+      struct per_xvec_messages *next = iter->next;
+
+      if (iter->targ == targ)
+	print_warnmsg (&iter->messages);
+      clear_warnmsg (&iter->messages);
+      if (iter != list)
+	free (iter);
+      iter = next;
+    }
 }
 
 /* This a copy of lto_section defined in GCC (lto-streamer.h).  */
@@ -357,8 +381,8 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
   unsigned int initial_section_id = _bfd_section_id;
   struct bfd_preserve preserve, preserve_match;
   bfd_cleanup cleanup = NULL;
-  bfd_error_handler_type orig_error_handler;
-  static int in_check_format;
+  struct per_xvec_messages messages = { abfd, PER_XVEC_NO_TARGET, NULL, NULL };
+  struct per_xvec_messages *orig_messages;
 
   if (matching != NULL)
     *matching = NULL;
@@ -392,11 +416,7 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
 
   /* Don't report errors on recursive calls checking the first element
      of an archive.  */
-  if (in_check_format)
-    orig_error_handler = bfd_set_error_handler (null_error_handler);
-  else
-    orig_error_handler = _bfd_set_error_handler_caching (abfd);
-  ++in_check_format;
+  orig_messages = _bfd_set_error_handler_caching (&messages);
 
   preserve_match.marker = NULL;
   if (!bfd_preserve_save (abfd, &preserve, NULL))
@@ -638,15 +658,9 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
       if (preserve_match.marker != NULL)
 	bfd_preserve_finish (abfd, &preserve_match);
       bfd_preserve_finish (abfd, &preserve);
-      bfd_set_error_handler (orig_error_handler);
+      _bfd_restore_error_handler_caching (orig_messages);
 
-      struct per_xvec_message **list = _bfd_per_xvec_warn (abfd->xvec, 0);
-      if (*list)
-	print_warnmsg (list);
-      list = _bfd_per_xvec_warn (NULL, 0);
-      for (size_t i = 0; i < _bfd_target_vector_entries + 1; i++)
-	clear_warnmsg (list++);
-      --in_check_format;
+      print_and_clear_messages (&messages, abfd->xvec);
 
       bfd_set_lto_type (abfd);
 
@@ -692,27 +706,8 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
   if (preserve_match.marker != NULL)
     bfd_preserve_finish (abfd, &preserve_match);
   bfd_preserve_restore (abfd, &preserve);
-  bfd_set_error_handler (orig_error_handler);
-  struct per_xvec_message **list = _bfd_per_xvec_warn (NULL, 0);
-  struct per_xvec_message **one = NULL;
-  for (size_t i = 0; i < _bfd_target_vector_entries + 1; i++)
-    {
-      if (list[i])
-	{
-	  if (!one)
-	    one = list + i;
-	  else
-	    {
-	      one = NULL;
-	      break;
-	    }
-	}
-    }
-  if (one)
-    print_warnmsg (one);
-  for (size_t i = 0; i < _bfd_target_vector_entries + 1; i++)
-    clear_warnmsg (list++);
-  --in_check_format;
+  _bfd_restore_error_handler_caching (orig_messages);
+  print_and_clear_messages (&messages, PER_XVEC_NO_TARGET);
   return false;
 }
 
diff --git a/bfd/libbfd.h b/bfd/libbfd.h
index 5f5ad2d..d106262 100644
--- a/bfd/libbfd.h
+++ b/bfd/libbfd.h
@@ -963,7 +963,29 @@ void _bfd_clear_error_data (void) ATTRIBUTE_HIDDEN;
 
 char *bfd_asprintf (const char *fmt, ...) ATTRIBUTE_HIDDEN;
 
-bfd_error_handler_type _bfd_set_error_handler_caching (bfd *) ATTRIBUTE_HIDDEN;
+/* Cached _bfd_check_format messages are put in this.  */
+struct per_xvec_message
+{
+  struct per_xvec_message *next;
+  char message[];
+};
+
+/* A list of per_xvec_message objects.  The targ field indicates
+   which xvec this list holds; PER_XVEC_NO_TARGET is only set for the
+   root of the list and indicates that the entry isn't yet used.  The
+   abfd field is only needed in the root entry of the list.  */
+struct per_xvec_messages
+{
+  bfd *abfd;
+  const bfd_target *targ;
+  struct per_xvec_message *messages;
+  struct per_xvec_messages *next;
+};
+
+#define PER_XVEC_NO_TARGET ((const bfd_target *) -1)
+struct per_xvec_messages *_bfd_set_error_handler_caching (struct per_xvec_messages *) ATTRIBUTE_HIDDEN;
+
+void _bfd_restore_error_handler_caching (struct per_xvec_messages *) ATTRIBUTE_HIDDEN;
 
 const char *_bfd_get_error_program_name (void) ATTRIBUTE_HIDDEN;
 
@@ -3708,15 +3730,6 @@ bool _bfd_write_stab_strings (bfd *, struct stab_info *) ATTRIBUTE_HIDDEN;
 bfd_vma _bfd_stab_section_offset (asection *, void *, bfd_vma) ATTRIBUTE_HIDDEN;
 
 /* Extracted from targets.c.  */
-/* Cached _bfd_check_format messages are put in this.  */
-struct per_xvec_message
-{
-  struct per_xvec_message *next;
-  char message[];
-};
-
-struct per_xvec_message **_bfd_per_xvec_warn (const bfd_target *, size_t) ATTRIBUTE_HIDDEN;
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/bfd/targets.c b/bfd/targets.c
index 532b646..0d5d73b 100644
--- a/bfd/targets.c
+++ b/bfd/targets.c
@@ -1454,9 +1454,6 @@ const bfd_target *const *const bfd_associated_vector = _bfd_associated_vector;
    number of entries that the array could possibly need.  */
 const size_t _bfd_target_vector_entries = ARRAY_SIZE (_bfd_target_vector);
 
-/* A place to stash a warning from _bfd_check_format.  */
-static struct per_xvec_message *per_xvec_warn[ARRAY_SIZE (_bfd_target_vector)
-					      + 1];
 
 /* This array maps configuration triplets onto BFD vectors.  */
 
@@ -1476,61 +1473,6 @@ static const struct targmatch bfd_target_match[] = {
   { NULL, NULL }
 };
 
-/*
-INTERNAL
-.{* Cached _bfd_check_format messages are put in this.  *}
-.struct per_xvec_message
-.{
-.  struct per_xvec_message *next;
-.  char message[];
-.};
-.
-INTERNAL_FUNCTION
-	_bfd_per_xvec_warn
-
-SYNOPSIS
-	struct per_xvec_message **_bfd_per_xvec_warn (const bfd_target *, size_t);
-
-DESCRIPTION
-	Return a location for the given target xvec to use for
-	warnings specific to that target.  If TARG is NULL, returns
-	the array of per_xvec_message pointers, otherwise if ALLOC is
-	zero, returns a pointer to a pointer to the list of messages
-	for TARG, otherwise (both TARG and ALLOC non-zero), allocates
-	a new 	per_xvec_message with space for a string of ALLOC
-	bytes and returns a pointer to a pointer to it.  May return a
-	pointer to a NULL pointer on allocation failure.
-*/
-
-struct per_xvec_message **
-_bfd_per_xvec_warn (const bfd_target *targ, size_t alloc)
-{
-  size_t idx;
-
-  if (!targ)
-    return per_xvec_warn;
-  for (idx = 0; idx < ARRAY_SIZE (_bfd_target_vector); idx++)
-    if (_bfd_target_vector[idx] == targ)
-      break;
-  struct per_xvec_message **m = per_xvec_warn + idx;
-  if (!alloc)
-    return m;
-  int count = 0;
-  while (*m)
-    {
-      m = &(*m)->next;
-      count++;
-    }
-  /* Anti-fuzzer measure.  Don't cache more than 5 messages.  */
-  if (count < 5)
-    {
-      *m = bfd_malloc (sizeof (**m) + alloc);
-      if (*m != NULL)
-	(*m)->next = NULL;
-    }
-  return m;
-}
-
 /* Find a target vector, given a name or configuration triplet.  */
 
 static const bfd_target *