symbols for bfd_simple_get_relocated_section_contents

Alan Modra amodra@gmail.com
Sat Aug 20 22:32:26 GMT 2022


If symbols are provided by the caller of this function they are
passed on to bfd_get_relocated_section_contents.  No surprises there.
It gets a little weird if they are not provided.  In that case they
are read from the bfd by _bfd_generic_link_add_symbols, and global
symbols are added to the generic linker hash table.  Global symbols
are not added to the linker hash table if symbols *are* provided.  Now
the linker hash table symbols are not used by the generic
bfd_get_relocated_section_conents, and also not by most target
versions when called from bfd_simple_get_relocated_section_contents
except for symbols like "_gp".  So it mostly doesn't matter whether
symbols are in the linker hash table, but it's odd that there is a
difference.  We could always add them, but I'm inclined to think that
is unnecessary work so this patch always leaves them out.  cc'ing the
gdb list since the uses in gdb/symfile.c and gdb/machoread.c are
possibly affected.

Also, symbols are canonicalized and written into a malloc'd buffer.
The buffer isn't freed, see commit 8e16317ca5eb.  I don't know whether
that matters any more, but in any case I can't see why we need another
copy of the symbols when _bfd_generic_link_read_symbols has already
cached symbols.

	* simple.c (bfd_simple_get_relocated_section_contents): If not
	provided, read symbols via bfd_generic_link_read_symbols.  Do
	not create another copy of symbols.  Tidy failure exits.
	Minor tidy of bfd_get_relocated_section_contents and
	bfd_get_full_section_contents arguments.

diff --git a/bfd/simple.c b/bfd/simple.c
index 6ccafd2259d..67e326d4625 100644
--- a/bfd/simple.c
+++ b/bfd/simple.c
@@ -23,6 +23,7 @@
 #include "bfd.h"
 #include "libbfd.h"
 #include "bfdlink.h"
+#include "genlink.h"
 
 static void
 simple_dummy_add_to_set (struct bfd_link_info * info ATTRIBUTE_UNUSED,
@@ -209,7 +210,6 @@ bfd_simple_get_relocated_section_contents (bfd *abfd,
   struct bfd_link_order link_order;
   struct bfd_link_callbacks callbacks;
   bfd_byte *contents, *data;
-  int storage_needed;
   struct saved_offsets saved_offsets;
   bfd *link_next;
 
@@ -218,10 +218,9 @@ bfd_simple_get_relocated_section_contents (bfd *abfd,
   if ((abfd->flags & (HAS_RELOC | EXEC_P | DYNAMIC)) != HAS_RELOC
       || ! (sec->flags & SEC_RELOC))
     {
-      contents = outbuf;
-      if (!bfd_get_full_section_contents (abfd, sec, &contents))
+      if (!bfd_get_full_section_contents (abfd, sec, &outbuf))
 	return NULL;
-      return contents;
+      return outbuf;
     }
 
   /* In order to use bfd_get_relocated_section_contents, we need
@@ -259,16 +258,13 @@ bfd_simple_get_relocated_section_contents (bfd *abfd,
   link_order.u.indirect.section = sec;
 
   data = NULL;
+  contents = NULL;
   if (outbuf == NULL)
     {
       bfd_size_type amt = sec->rawsize > sec->size ? sec->rawsize : sec->size;
       data = (bfd_byte *) bfd_malloc (amt);
       if (data == NULL)
-	{
-	  _bfd_generic_link_hash_table_free (abfd);
-	  abfd->link.next = link_next;
-	  return NULL;
-	}
+	goto out1;
       outbuf = data;
     }
 
@@ -276,37 +272,29 @@ bfd_simple_get_relocated_section_contents (bfd *abfd,
   saved_offsets.sections = malloc (sizeof (*saved_offsets.sections)
 				   * saved_offsets.section_count);
   if (saved_offsets.sections == NULL)
-    {
-      free (data);
-      _bfd_generic_link_hash_table_free (abfd);
-      abfd->link.next = link_next;
-      return NULL;
-    }
+    goto out2;
   bfd_map_over_sections (abfd, simple_save_output_info, &saved_offsets);
 
   if (symbol_table == NULL)
     {
-      _bfd_generic_link_add_symbols (abfd, &link_info);
-
-      storage_needed = bfd_get_symtab_upper_bound (abfd);
-      symbol_table = (asymbol **) bfd_malloc (storage_needed);
-      bfd_canonicalize_symtab (abfd, symbol_table);
+      if (!bfd_generic_link_read_symbols (abfd))
+	goto out3;
+      symbol_table = _bfd_generic_link_get_symbols (abfd);
     }
-  else
-    storage_needed = 0;
 
   contents = bfd_get_relocated_section_contents (abfd,
 						 &link_info,
 						 &link_order,
 						 outbuf,
-						 0,
+						 false,
 						 symbol_table);
-  if (contents == NULL)
-    free (data);
-
+ out3:
   bfd_map_over_sections (abfd, simple_restore_output_info, &saved_offsets);
   free (saved_offsets.sections);
-
+ out2:
+  if (contents == NULL)
+    free (data);
+ out1:
   _bfd_generic_link_hash_table_free (abfd);
   abfd->link.next = link_next;
   return contents;

-- 
Alan Modra
Australia Development Lab, IBM


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