[GOLD] PowerPC .gnu.attributes support

elfcpp/
	* powerpc.h (Tag_GNU_Power_ABI_FP): Define.
	(Tag_GNU_Power_ABI_Vector, Tag_GNU_Power_ABI_Struct_Return): Define.
gold/
	* powerpc.cc: Include attributes.h.
	(Powerpc_relobj::attributes_section_data_): New variable, with
	accessor and associated constructor and destructor support.
	(Powerpc_dynobj::attributes_section_data_): Likewise.
	(Powerpc_relobj::do_read_symbols): Stash SHT_GNU_ATTRIBUTES section
	contents in attributes_section_data_.
	(Powerpc_dynobj::do_read_symbols): Likewise.
	(Target_powerpc): Add attributes_section_data_, last_fp_, last_ld_,
	last_vec_, and last_struct_ vars.
	(Target_powerpc::merge_object_attributes): New function.
	(Target_powerpc::do_finalize_sections): Iterate over input objects
	merging attributes.  Create output attributes section.

1 files changed, 26 insertions, 0 deletions

diff --git a/elfcpp/powerpc.h b/elfcpp/powerpc.h
index 71de459..5996691 100644
--- a/elfcpp/powerpc.h
+++ b/elfcpp/powerpc.h
@@ -230,6 +230,32 @@ enum
   EF_PPC64_ABI = 3
 };
 
+// Object attribute tags.  0-3 are generic.
+enum
+{
+  // FP ABI, low 2 bits:
+  // 1 for double precision hard-float,
+  // 2 for soft-float,
+  // 3 for single precision hard-float.
+  // 0 for not tagged or not using any ABIs affected by the differences.
+  // Next 2 bits:
+  // 1 for ibm long double
+  // 2 for 64-bit long double
+  // 3 for IEEE long double.
+  // 0 for not tagged or not using any ABIs affected by the differences.
+  Tag_GNU_Power_ABI_FP = 4,
+
+  // Value 1 for general purpose registers only, 2 for AltiVec
+  // registers, 3 for SPE registers; 0 for not tagged or not using any
+  // ABIs affected by the differences.
+  Tag_GNU_Power_ABI_Vector = 8,
+
+  // Value 1 for ABIs using r3/r4 for returning structures <= 8 bytes,
+  // 2 for ABIs using memory; 0 for not tagged or not using any ABIs
+  // affected by the differences.
+  Tag_GNU_Power_ABI_Struct_Return = 12
+};
+
 // DT_PPC_OPT bits
 enum
 {