PATCH: PR ld/6931: COMDAT group is broken

["H.J. Lu" <hongjiu.lu@intel.com>]

bfd_elf_set_group_contents needs to handle group signature properly for
ld -r. The sh_info field of group section has the symbol table index 
of group signature. We need to get the symbol table index of group
signature in output file. We start with the symbol table index for
group signature in input file. If it is a global symbol, we can get
its index from ELF symbol hash table. If it is a local symbol, we
have to first get the symbol table entry for group signature in
input file and then compute the symbol table index in output file.

OK to install?


H.J.
--
bfd/

2008-10-02  H.J. Lu  <hongjiu.lu@intel.com>

	PR ld/6931
	* elf.c (bfd_elf_set_group_contents): Properly get the symbol
	table index for group signature for ld -r.

ld/testsuite/

2008-10-02  H.J. Lu  <hongjiu.lu@intel.com>

	PR ld/6931
	* ld-elf/group4.d: New.
	* ld-elf/group5.d: Likewise.
	* ld-elf/group6.d: Likewise.

--- binutils/bfd/elf.c.grp	2008-10-02 13:52:45.000000000 -0700
+++ binutils/bfd/elf.c	2008-10-02 14:00:14.000000000 -0700
@@ -2715,11 +2715,73 @@ bfd_elf_set_group_contents (bfd *abfd, a
   if (symindx == 0)
     {
       /* If called from the assembler, swap_out_syms will have set up
-	 elf_section_syms;  If called for "ld -r", use target_index.  */
+	 elf_section_syms.  */
       if (elf_section_syms (abfd) != NULL)
 	symindx = elf_section_syms (abfd)[sec->index]->udata.i;
       else
-	symindx = sec->target_index;
+	{
+	  struct bfd_link_order *lo;
+	  asection *input;
+	  Elf_Internal_Shdr *symtab_hdr;
+
+	  /* Handle "ld -r".  */
+	  input = NULL;
+	  for (lo = sec->map_head.link_order; lo != NULL; lo = lo->next)
+	    if (lo->type == bfd_indirect_link_order)
+	      {
+		/* There should be only one input section.  */
+		BFD_ASSERT (input == NULL);
+
+		input = lo->u.indirect.section;
+		/* Get the symbol table index for group signature in
+		   input file.  */
+		symindx = elf_section_data(input)->this_hdr.sh_info;
+	      }
+
+	  BFD_ASSERT (input != NULL);
+
+	  symtab_hdr = &elf_symtab_hdr (input->owner);
+	  if (symindx < symtab_hdr->sh_info)
+	    {
+	      unsigned char esym[sizeof (Elf64_External_Sym)];
+	      Elf_External_Sym_Shndx eshndx;
+	      Elf_Internal_Sym isym;
+	      Elf_Internal_Shdr *elf_sect;
+	      int target_index;
+
+	      /* Get the symbol table entry for group signature in
+		 input file.  */
+	      if (bfd_elf_get_elf_syms (input->owner, symtab_hdr, 1, 
+					symindx, &isym, esym, &eshndx)
+		  == NULL)
+		abort ();
+
+	      /* Get the group signature section in input file.  */
+	      elf_sect = elf_elfsections (input->owner)[isym.st_shndx];
+
+	      /* Compute the symbol table index for group signature
+		 in output file.  */
+	      target_index
+		= elf_sect->bfd_section->output_section->target_index;
+	      if (ELF_ST_TYPE (isym.st_info) == STT_SECTION)
+		symindx = target_index;
+	      else
+		symindx += target_index;
+	    }
+	  else
+	    {
+	      struct elf_link_hash_entry **sym_hashes;
+	      struct elf_link_hash_entry *h;
+
+	      sym_hashes = elf_sym_hashes (input->owner);
+	      h = sym_hashes[symindx - symtab_hdr->sh_info];
+	      while (h->root.type == bfd_link_hash_indirect
+		     || h->root.type == bfd_link_hash_warning)
+		h = (struct elf_link_hash_entry *) h->root.u.i.link;
+	      symindx = h->indx;
+	    }
+	}
+      BFD_ASSERT (symindx != 0);
     }
   elf_section_data (sec)->this_hdr.sh_info = symindx;
 
--- binutils/ld/testsuite/ld-elf/group4.d.grp	2008-10-02 13:52:46.000000000 -0700
+++ binutils/ld/testsuite/ld-elf/group4.d	2008-10-02 13:52:46.000000000 -0700
@@ -0,0 +1,16 @@
+#source: ../../../binutils/testsuite/binutils-all/group-2.s
+#ld: -r
+#readelf: -Sg --wide
+
+#...
+  \[[ 0-9]+\] .group[ \t]+GROUP[ \t]+.*
+#...
+  \[[ 0-9]+\] \.text.*[ \t]+PROGBITS[ \t0-9a-f]+AXG[ \t]+.*
+#...
+  \[[ 0-9]+\] \.data.*[ \t]+PROGBITS[ \t0-9a-f]+WAG[ \t]+.*
+#...
+COMDAT group section \[[ 0-9]+\] `.group' \[.text.foo\] contains 2 sections:
+   \[Index\]    Name
+   \[[ 0-9]+\]   .text.*
+   \[[ 0-9]+\]   .data.*
+#pass
--- binutils/ld/testsuite/ld-elf/group5.d.grp	2008-10-02 13:52:46.000000000 -0700
+++ binutils/ld/testsuite/ld-elf/group5.d	2008-10-02 13:52:46.000000000 -0700
@@ -0,0 +1,16 @@
+#source: ../../../binutils/testsuite/binutils-all/group-3.s
+#ld: -r
+#readelf: -Sg --wide
+
+#...
+  \[[ 0-9]+\] .group[ \t]+GROUP[ \t]+.*
+#...
+  \[[ 0-9]+\] \.text.*[ \t]+PROGBITS[ \t0-9a-f]+AXG[ \t]+.*
+#...
+  \[[ 0-9]+\] \.data.*[ \t]+PROGBITS[ \t0-9a-f]+WAG[ \t]+.*
+#...
+COMDAT group section \[[ 0-9]+\] `.group' \[foo\] contains 2 sections:
+   \[Index\]    Name
+   \[[ 0-9]+\]   .text.*
+   \[[ 0-9]+\]   .data.*
+#pass
--- binutils/ld/testsuite/ld-elf/group6.d.grp	2008-10-02 13:52:46.000000000 -0700
+++ binutils/ld/testsuite/ld-elf/group6.d	2008-10-02 13:52:46.000000000 -0700
@@ -0,0 +1,16 @@
+#source: ../../../binutils/testsuite/binutils-all/group-4.s
+#ld: -r
+#readelf: -Sg --wide
+
+#...
+  \[[ 0-9]+\] .group[ \t]+GROUP[ \t]+.*
+#...
+  \[[ 0-9]+\] \.text.*[ \t]+PROGBITS[ \t0-9a-f]+AXG[ \t]+.*
+#...
+  \[[ 0-9]+\] \.data.*[ \t]+PROGBITS[ \t0-9a-f]+WAG[ \t]+.*
+#...
+COMDAT group section \[[ 0-9]+\] `.group' \[foo\] contains 2 sections:
+   \[Index\]    Name
+   \[[ 0-9]+\]   .text.*
+   \[[ 0-9]+\]   .data.*
+#pass