Rewrite ppc32 backend .sdata and .sdata2 handling

1) _SDA_BASE_ and _SDA2_BASE_ and defined automatically, in a similar
   manner to the way _GLOBAL_OFFSET_TABLE_ is handled.  It's a little
   more complicated to remove the symbols because _SDA_BASE_ needs to
   be there if either .sdata or .sbss is present, and similarly for
   _SDA2_BASE.
2) The linker created .sdata and .sdata2 sections used for
   R_PPC_EMB_SDAI16 and R_PPC_EMB_SDA2I16 pointers are created early.
   Nowadays we strip unneeded sections from the output, so it isn't
   necessary to delay creating the sections.
3) The output section for targets of various SDA relocs is now checked
   as per the ABI(s).  We previously allowed .sdata.foo and similar,
   most likely because at some stage we were checking input sections.

Also, the patch fixes a long-standing bug in size_input_sections
that affects the values of symbols defined in stripped input
sections.

	PR 16952
bfd/
	* elf32-ppc.c (ppc_elf_create_linker_section): Move earlier.
	Remove redundant setting of htab->elf.dynobj.  Don't align.
	Define .sdata symbols using _bfd_elf_define_linkage_sym.
	(ppc_elf_create_glink): Call ppc_elf_create_linker_section.
	(create_sdata_sym): Delete.
	(elf_allocate_pointer_linker_section): Rename from
	elf_create_pointer_linker_section.  Align section.
	(ppc_elf_check_relocs): Don't call ppc_elf_creat_linker_section
	directly here, or create_sdata_sym.  Set ref_regular on _SDA_BASE_
	and _SDA2_BASE_.
	(ppc_elf_size_dynamic_sections): Remove ATTRIBUTE_UNUSED on param.
	Remove unnecessary tests on _SDA_BASE_ sym.
	(maybe_strip_sdasym, ppc_elf_maybe_strip_sdata_syms): New functions.
	(ppc_elf_relocate_section): Tighten SDA reloc symbol section checks.
	* elf32-ppc.h (ppc_elf_set_sdata_syms): Delete.
	(ppc_elf_maybe_strip_sdata_syms): Declare.
ld/
	* emulparams/elf32ppccommon.sh (_SDA_BASE_, _SDA2_BASE_): Delete.
	* emultempl/ppc32elf.em (ppc_before_allocation): Call
	ppc_elf_maybe_strip_sdata_syms.
	* ldlang.c (size_input_section): Correct output_offset value
	for excluded input sections.

4 files changed, 17 insertions, 11 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index b8e926e..53f9f94 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,12 @@
+2014-05-20  Alan Modra  <amodra@gmail.com>
+
+	PR 16952
+	* emulparams/elf32ppccommon.sh (_SDA_BASE_, _SDA2_BASE_): Delete.
+	* emultempl/ppc32elf.em (ppc_before_allocation): Call
+	ppc_elf_maybe_strip_sdata_syms.
+	* ldlang.c (size_input_section): Correct output_offset value
+	for excluded input sections.
+
 2014-05-16  John Marino  <binutils@marino.st>
 
 	* configure.tgt: Add /lib to dragonfly NATIVE_LIB_DIRS.
diff --git a/ld/emulparams/elf32ppccommon.sh b/ld/emulparams/elf32ppccommon.sh
index 049fdb9..1f54ef8 100644
--- a/ld/emulparams/elf32ppccommon.sh
+++ b/ld/emulparams/elf32ppccommon.sh
@@ -13,8 +13,6 @@ ARCH=powerpc:common
 MACHINE=
 EXECUTABLE_SYMBOLS='PROVIDE (__stack = 0); PROVIDE (___stack = 0);'
 if test -z "${CREATE_SHLIB}"; then
-  SDATA_START_SYMBOLS="PROVIDE (_SDA_BASE_ = 32768);"
-  SDATA2_START_SYMBOLS="PROVIDE (_SDA2_BASE_ = 32768);"
   SBSS_START_SYMBOLS="PROVIDE (__sbss_start = .); PROVIDE (___sbss_start = .);"
   SBSS_END_SYMBOLS="PROVIDE (__sbss_end = .); PROVIDE (___sbss_end = .);"
 else
diff --git a/ld/emultempl/ppc32elf.em b/ld/emultempl/ppc32elf.em
index 069acd2..0e2af12 100644
--- a/ld/emultempl/ppc32elf.em
+++ b/ld/emultempl/ppc32elf.em
@@ -135,6 +135,8 @@ ppc_before_allocation (void)
 
   gld${EMULATION_NAME}_before_allocation ();
 
+  ppc_elf_maybe_strip_sdata_syms (&link_info);
+
   if (RELAXATION_ENABLED)
     params.branch_trampolines = 1;
 
diff --git a/ld/ldlang.c b/ld/ldlang.c
index 8d1e3f7..7c076a2 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -4608,12 +4608,15 @@ size_input_section
 {
   lang_input_section_type *is = &((*this_ptr)->input_section);
   asection *i = is->section;
+  asection *o = output_section_statement->bfd_section;
 
-  if (i->sec_info_type != SEC_INFO_TYPE_JUST_SYMS
-      && (i->flags & SEC_EXCLUDE) == 0)
+  if (i->sec_info_type == SEC_INFO_TYPE_JUST_SYMS)
+    i->output_offset = i->vma - o->vma;
+  else if ((i->flags & SEC_EXCLUDE) != 0)
+    i->output_offset = dot - o->vma;
+  else
     {
       bfd_size_type alignment_needed;
-      asection *o;
 
       /* Align this section first to the input sections requirement,
 	 then to the output section's requirement.  If this alignment
@@ -4623,7 +4626,6 @@ size_input_section
       if (output_section_statement->subsection_alignment != -1)
 	i->alignment_power = output_section_statement->subsection_alignment;
 
-      o = output_section_statement->bfd_section;
       if (o->alignment_power < i->alignment_power)
 	o->alignment_power = i->alignment_power;
 
@@ -4636,17 +4638,12 @@ size_input_section
 	}
 
       /* Remember where in the output section this input section goes.  */
-
       i->output_offset = dot - o->vma;
 
       /* Mark how big the output section must be to contain this now.  */
       dot += TO_ADDR (i->size);
       o->size = TO_SIZE (dot - o->vma);
     }
-  else
-    {
-      i->output_offset = i->vma - output_section_statement->bfd_section->vma;
-    }
 
   return dot;
 }