Re: EXTERN doesn't work as -u

[Alan Modra]

On Thu, Mar 14, 2002 at 12:07:53PM +0100, Marcus Brinkmann wrote:
> ulysses:/tmp# make
> echo 'main() {};' > foo.c
> cc    -c -o foo.o foo.c
> echo 'bar() { return 0; }' > bar.c
> cc    -c -o bar.o bar.c
> ar cru libbar.a bar.o
> ranlib libbar.a
> gcc -static -o foo1 foo.o -u bar libbar.a
> echo 'EXTERN(bar);' > libbar-script.a
> gcc -static -o foo2 foo.o libbar-script.a libbar.a
> objdump --syms foo1 | grep bar && echo BAR defined in foo1 || echo BAR 
> undefined in foo1
> 00000000 l    df *ABS*  00000000 bar.c
> 080481d0 g     F .text  00000009 bar
> BAR defined in foo1
> objdump --syms foo2 | grep bar && echo BAR defined in foo2 || echo BAR 
> undefined in foo2
> BAR undefined in foo2
> 
> I would expect that foo2 also contains the symbol bar.

Fixed like this.

ld/ChangeLog
        * ldlang.c (ldlang_add_undef): If the output bfd has been opened,
        add the symbol to the linker hash table immediately.
        (lang_place_undefineds): Split symbol creation out..
        (insert_undefined): ..to here.

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre

Index: ld/ldlang.c
===================================================================
RCS file: /cvs/src/src/ld/ldlang.c,v
retrieving revision 1.78
diff -u -p -r1.78 ldlang.c
--- ldlang.c    2002/03/18 02:55:51     1.78
+++ ldlang.c    2002/03/20 07:46:26
@@ -92,6 +92,7 @@ static bfd *open_output PARAMS ((const c
 static void ldlang_open_output PARAMS ((lang_statement_union_type *));
 static void open_input_bfds PARAMS ((lang_statement_union_type *, boolean));
 static void lang_reasonable_defaults PARAMS ((void));
+static void insert_undefined PARAMS ((const char *));
 static void lang_place_undefineds PARAMS ((void));
 static void map_input_to_output_sections
   PARAMS ((lang_statement_union_type *, const char *,
@@ -2010,7 +2011,11 @@ lang_reasonable_defaults ()
 }
 
 /* Add the supplied name to the symbol table as an undefined reference.
-   Remove items from the chain as we open input bfds.  */
+   This is a two step process as the symbol table doesn't even exist at
+   the time the ld command line is processed.  First we put the name
+   on a list, then, once the output file has been opened, transfer the
+   name to the symbol table.  */
+
 typedef struct ldlang_undef_chain_list
 {
   struct ldlang_undef_chain_list *next;
@@ -2031,6 +2036,28 @@ ldlang_add_undef (name)
   ldlang_undef_chain_list_head = new;
 
   new->name = xstrdup (name);
+
+  if (output_bfd != NULL)
+    insert_undefined (new->name);
+}
+
+/* Insert NAME as undefined in the symbol table.  */
+
+static void
+insert_undefined (name)
+     const char *name;
+{
+  struct bfd_link_hash_entry *h;
+
+  h = bfd_link_hash_lookup (link_info.hash, name, true, false, true);
+  if (h == (struct bfd_link_hash_entry *) NULL)
+    einfo (_("%P%F: bfd_link_hash_lookup failed: %E\n"));
+  if (h->type == bfd_link_hash_new)
+    {
+      h->type = bfd_link_hash_undefined;
+      h->u.undef.abfd = NULL;
+      bfd_link_add_undef (link_info.hash, h);
+    }
 }
 
 /* Run through the list of undefineds created above and place them
@@ -2046,17 +2073,7 @@ lang_place_undefineds ()
        ptr != (ldlang_undef_chain_list_type *) NULL;
        ptr = ptr->next)
     {
-      struct bfd_link_hash_entry *h;
-
-      h = bfd_link_hash_lookup (link_info.hash, ptr->name, true, false, true);
-      if (h == (struct bfd_link_hash_entry *) NULL)
-       einfo (_("%P%F: bfd_link_hash_lookup failed: %E\n"));
-      if (h->type == bfd_link_hash_new)
-       {
-         h->type = bfd_link_hash_undefined;
-         h->u.undef.abfd = NULL;
-         bfd_link_add_undef (link_info.hash, h);
-       }
+      insert_undefined (ptr->name);
     }
 }