Re: Bad patch to elf.c.

[Alan Modra <alan at linuxcare dot com dot au>]

On Thu, 12 Oct 2000, Alan Modra wrote:

> The attached patch seems to work for me, but I'll sleep on it first before
> committing to CVS.

This one is neater.  We might as well make use of the bfd section symbol
to store values.  DJ, take note I moved (and renamed) one of your comdat
structure fields, which was unused as far as I could see.

bfd/ChangeLog
	* section.c (struct sec): Add kept_section.
	(struct bfd_comdat_info): Remove sec, we can use above.
	(STD_SECTION): Add initializer.
	(bfd_make_section_anyway): Init here too.

	* bfd-in2.h: Regenerate.

	* elflink.h (elf_link_add_object_symbols): Remove unnecessary
	zeroing of `flags'.  
	(elf_link_input_bfd): Set all asection->symbol->value's here, and
	fudge values for discarded link-once section symbols.

ld/ChangeLog
	* ldlang.c (section_already_linked): Set kept_section instead of
	sec->comdat->sec.

Alan Modra
-- 
Linuxcare.  Support for the Revolution.

Index: bfd/elflink.h
===================================================================
RCS file: /cvs/src/src/bfd/elflink.h,v
retrieving revision 1.73
diff -u -p -r1.73 elflink.h
--- elflink.h	2000/10/07 13:40:33	1.73
+++ elflink.h	2000/10/12 02:47:48
@@ -1371,8 +1371,6 @@ elf_link_add_object_symbols (abfd, info)
 	  if (sym.st_shndx != SHN_UNDEF
 	      && sym.st_shndx != SHN_COMMON)
 	    flags = BSF_GLOBAL;
-	  else
-	    flags = 0;
 	}
       else if (bind == STB_WEAK)
 	flags = BSF_WEAK;
@@ -5536,14 +5534,41 @@ elf_link_input_bfd (finfo, input_bfd)
       if (esym == external_syms)
 	continue;
 
+      if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
+	{
+	  asection *ksec;
+
+	  /* Save away all section symbol values.  */
+	  if (isec != NULL)
+	    isec->symbol->value = isym->st_value;
+
+	  /* If this is a discarded link-once section symbol, update
+	     it's value to that of the kept section symbol.  The
+	     linker will keep the first of any matching link-once
+	     sections, so we should have already seen it's section
+	     symbol.  I trust no-one will have the bright idea of
+	     re-ordering the bfd list...  */
+	  if (isec != NULL
+	      && (bfd_get_section_flags (input_bfd, isec) & SEC_LINK_ONCE) != 0
+	      && (ksec = isec->kept_section) != NULL)
+	    {
+	      isym->st_value = ksec->symbol->value;
+
+	      /* That put the value right, but the section info is all
+		 wrong.  I hope this works.  */
+	      isec->output_offset = ksec->output_offset;
+	      isec->output_section = ksec->output_section;
+	    }
+
+	  /* We never output section symbols.  Instead, we use the
+	     section symbol of the corresponding section in the output
+	     file.  */
+	  continue;
+	}
+
       /* If we are stripping all symbols, we don't want to output this
 	 one.  */
       if (finfo->info->strip == strip_all)
-	continue;
-
-      /* We never output section symbols.  Instead, we use the section
-	 symbol of the corresponding section in the output file.  */
-      if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
 	continue;
 
       /* If we are discarding all local symbols, we don't want to
Index: bfd/section.c
===================================================================
RCS file: /cvs/src/src/bfd/section.c,v
retrieving revision 1.24
diff -u -p -r1.24 section.c
--- section.c	2000/10/10 15:23:38	1.24
+++ section.c	2000/10/12 02:47:53
@@ -165,10 +165,6 @@ CODE_FRAGMENT
 .     specific code; it is not an index into the list returned by
 .     bfd_canonicalize_symtab.  *}
 .  long symbol;
-.
-.  {* If this section is being discarded, the linker uses this field
-.     to point to the input section which is being kept.  *}
-.  struct sec *sec;
 .};
 .
 .typedef struct sec
@@ -471,6 +467,10 @@ CODE_FRAGMENT
 .
 .  struct bfd_comdat_info *comdat;
 .
+.  {* Points to the kept section if this section is a link-once section,
+.     and is discarded.  *}
+.  struct sec *kept_section;
+.
 .  {* When a section is being output, this value changes as more
 .     linenumbers are written out.  *}
 .
@@ -578,11 +578,11 @@ static const asymbol global_syms[] =
     /* line_filepos, userdata, contents, lineno, lineno_count,       */	\
        0,            NULL,     NULL,     NULL,   0,			\
 									\
-    /* comdat, moving_line_filepos, target_index, used_by_bfd,       */	\
-       NULL,   0,                   0,            NULL,			\
+    /* comdat, kept_section, moving_line_filepos, target_index,      */	\
+       NULL,   NULL,         0,                   0,			\
 									\
-    /* constructor_chain, owner,                                     */	\
-       NULL,              NULL,						\
+    /* used_by_bfd, constructor_chain, owner,                        */	\
+       NULL,        NULL,              NULL,				\
 									\
     /* symbol,                                                       */	\
        (struct symbol_cache_entry *) &global_syms[IDX],			\
@@ -789,6 +789,7 @@ bfd_make_section_anyway (abfd, name)
   newsect->line_filepos = 0;
   newsect->owner = abfd;
   newsect->comdat = NULL;
+  newsect->kept_section = NULL;
 
   /* Create a symbol whos only job is to point to this section. This is
      useful for things like relocs which are relative to the base of a
Index: ld/ldlang.c
===================================================================
RCS file: /cvs/src/src/ld/ldlang.c,v
retrieving revision 1.33
diff -u -p -r1.33 ldlang.c
--- ldlang.c	2000/10/09 15:09:17	1.33
+++ ldlang.c	2000/10/12 02:48:56
@@ -995,8 +995,7 @@ section_already_linked (abfd, sec, data)
 	     discarded, we must retain a pointer to the section which
 	     we are really going to use.  */
 	  sec->output_section = bfd_abs_section_ptr;
-	  if (sec->comdat != NULL)
-	    sec->comdat->sec = l->sec;
+	  sec->kept_section = l->sec;
 
 	  return;
 	}