Refactor gold to enable support for MIPS-64 relocation format.

For MIPS-64, the r_info field in the relocation format is
replaced by several individual fields, including r_sym and
r_type. To enable support for this format, I've refactored
target-independent code to remove almost all uses of the r_info
field. (I've left alone a couple of routines used only for
incremental linking, which I can update if/when the MIPS target
adds support for incremental linking.)

For routines that are already templated on a Classify_reloc class
(namely, gc_process_relocs, relocate_section, and
relocate_relocs), I've extended the Classify_reloc interface to
include sh_type (which no longer needs to be a separate template
parameter) as well as get_r_sym() and get_r_type() methods for
extracting the r_sym and r_type fields. For
scan_relocatable_relocs, I've extended the
Default_scan_relocatable_relocs class by converting it to a class
template with Classify_reloc as a template parameter. For the
remaining routines that need to access r_sym, I've added a
virtual Target::get_r_sym() method with an override for the MIPS
target.

In elfcpp, I've added Mips64_rel, etc., accessor classes and
corresponding internal data structures. The MIPS target uses
these new classes within its own Mips_classify_reloc class.
The Mips64_ accessor classes also expose the r_ssym, r_type2,
and r_type3 fields from the relocation.

These changes should be functionally the same for all but the
MIPS target.

elfcpp/
	* elfcpp.h (Mips64_rel, Mips64_rel_write): New classes.
	(Mips64_rela, Mips64_rela_write): New classes.
	* elfcpp_internal.h (Mips64_rel_data, Mips64_rela_data): New structs.

gold/
	* gc.h (get_embedded_addend_size): Remove sh_type parameter.
	(gc_process_relocs): Remove sh_type template parameter.
	Use Classify_reloc to access r_sym, r_type, and r_addend fields.
	* object.h (Sized_relobj_file::split_stack_adjust): Add target
	parameter.
	(Sized_relobj_file::split_stack_adjust_reltype): Likewise.
	* reloc-types.h (Reloc_types::copy_reloc_addend): (SHT_REL and SHT_RELA
	specializations) Remove.
	* reloc.cc (Emit_relocs_strategy): Rename and move to target-reloc.h.
	(Sized_relobj_file::emit_relocs_scan): Call Target::emit_relocs_scan().
	(Sized_relobj_file::emit_relocs_scan_reltype): Remove.
	(Sized_relobj_file::split_stack_adjust): Add target parameter.
	Adjust all callers.
	(Sized_relobj_file::split_stack_adjust_reltype): Likewise. Call
	Target::get_r_sym() to get r_sym field from relocations.
	(Track_relocs::next_symndx): Call Target::get_r_sym().
	* target-reloc.h (scan_relocs): Remove sh_type template parameter;
	add Classify_reloc template parameter.  Use for accessing r_sym and
	r_type.
	(relocate_section): Likewise.
	(Default_classify_reloc): New class (renamed and moved from reloc.cc).
	(Default_scan_relocatable_relocs): Remove sh_type template parameter.
	(Default_scan_relocatable_relocs::Reltype): New typedef.
	(Default_scan_relocatable_relocs::reloc_size): New const.
	(Default_scan_relocatable_relocs::sh_type): New const.
	(Default_scan_relocatable_relocs::get_r_sym): New method.
	(Default_scan_relocatable_relocs::get_r_type): New method.
	(Default_emit_relocs_strategy): New class.
	(scan_relocatable_relocs): Replace sh_type template parameter with
	Scan_relocatable_relocs class.  Use it to access r_sym and r_type
	fields.
	(relocate_relocs): Replace sh_type template parameter with
	Classify_reloc class.  Use it to access r_sym and r_type fields.
	* target.h (Target::is_call_to_non_split): Replace r_type parameter
	with pointer to relocation. Adjust all callers.
	(Target::do_is_call_to_non_split): Likewise.
	(Target::emit_relocs_scan): New virtual method.
	(Sized_target::get_r_sym): New virtual method.
	* target.cc (Target::do_is_call_to_non_split): Replace r_type parameter
	with pointer to relocation.

	* aarch64.cc (Target_aarch64::emit_relocs_scan): New method.
	(Target_aarch64::Relocatable_size_for_reloc): Remove.
	(Target_aarch64::gc_process_relocs): Use Default_classify_reloc.
	(Target_aarch64::scan_relocs): Likewise.
	(Target_aarch64::relocate_section): Likewise.
	(Target_aarch64::Relocatable_size_for_reloc::get_size_for_reloc):
	Remove.
	(Target_aarch64::scan_relocatable_relocs): Use Default_classify_reloc.
	(Target_aarch64::relocate_relocs): Use Default_classify_reloc.
	* arm.cc (Target_arm::Arm_scan_relocatable_relocs): Remove sh_type
	template parameter.
	(Target_arm::emit_relocs_scan): New method.
	(Target_arm::Relocatable_size_for_reloc): Replace with...
	(Target_arm::Classify_reloc): ...this.
	(Target_arm::gc_process_relocs): Use Classify_reloc.
	(Target_arm::scan_relocs): Likewise.
	(Target_arm::relocate_section): Likewise.
	(Target_arm::scan_relocatable_relocs): Likewise.
	(Target_arm::relocate_relocs): Likewise.
	* i386.cc (Target_i386::emit_relocs_scan): New method.
	(Target_i386::Relocatable_size_for_reloc): Replace with...
	(Target_i386::Classify_reloc): ...this.
	(Target_i386::gc_process_relocs): Use Classify_reloc.
	(Target_i386::scan_relocs): Likewise.
	(Target_i386::relocate_section): Likewise.
	(Target_i386::scan_relocatable_relocs): Likewise.
	(Target_i386::relocate_relocs): Likewise.
	* mips.cc (Mips_scan_relocatable_relocs): Remove sh_type template
	parameter.
	(Mips_reloc_types): New class template.
	(Mips_classify_reloc): New class template.
	(Target_mips::Reltype): New typedef.
	(Target_mips::Relatype): New typedef.
	(Target_mips::emit_relocs_scan): New method.
	(Target_mips::get_r_sym): New method.
	(Target_mips::Relocatable_size_for_reloc): Replace with
	Mips_classify_reloc.
	(Target_mips::copy_reloc): Use Mips_classify_reloc.
	(Target_mips::gc_process_relocs): Likewise.
	(Target_mips::scan_relocs): Likewise.
	(Target_mips::relocate_section): Likewise.
	(Target_mips::scan_relocatable_relocs): Likewise.
	(Target_mips::relocate_relocs): Likewise.
	(mips_get_size_for_reloc): New function, factored out from
	Relocatable_size_for_reloc::get_size_for_reloc.
	(Target_mips::Scan::local): Use Mips_classify_reloc.
	(Target_mips::Scan::global): Likewise.
	(Target_mips::Relocate::relocate): Likewise.
	* powerpc.cc (Target_powerpc::emit_relocs_scan): New method.
	(Target_powerpc::Relocatable_size_for_reloc): Remove.
	(Target_powerpc::gc_process_relocs): Use Default_classify_reloc.
	(Target_powerpc::scan_relocs): Likewise.
	(Target_powerpc::relocate_section): Likewise.
	(Powerpc_scan_relocatable_reloc): Convert to class template.
	(Powerpc_scan_relocatable_reloc::Reltype): New typedef.
	(Powerpc_scan_relocatable_reloc::reloc_size): New const.
	(Powerpc_scan_relocatable_reloc::sh_type): New const.
	(Powerpc_scan_relocatable_reloc::get_r_sym): New method.
	(Powerpc_scan_relocatable_reloc::get_r_type): New method.
	(Target_powerpc::scan_relocatable_relocs): Use
	Powerpc_scan_relocatable_reloc.
	(Target_powerpc::relocate_relocs): Use Default_classify_reloc.
	* s390.cc (Target_s390::emit_relocs_scan): New method.
	(Target_s390::Relocatable_size_for_reloc): Remove.
	(Target_s390::gc_process_relocs): Use Default_classify_reloc.
	(Target_s390::scan_relocs): Likewise.
	(Target_s390::relocate_section): Likewise.
	(Target_s390::Relocatable_size_for_reloc::get_size_for_reloc):
	Remove.
	(Target_s390::scan_relocatable_relocs): Use Default_classify_reloc.
	(Target_s390::relocate_relocs): Use Default_classify_reloc.
	* sparc.cc (Target_sparc::emit_relocs_scan): New method.
	(Target_sparc::Relocatable_size_for_reloc): Remove.
	(Target_sparc::gc_process_relocs): Use Default_classify_reloc.
	(Target_sparc::scan_relocs): Likewise.
	(Target_sparc::relocate_section): Likewise.
	(Target_sparc::Relocatable_size_for_reloc::get_size_for_reloc):
	Remove.
	(Target_sparc::scan_relocatable_relocs): Use Default_classify_reloc.
	(Target_sparc::relocate_relocs): Use Default_classify_reloc.
	* tilegx.cc (Target_tilegx::emit_relocs_scan): New method.
	(Target_tilegx::Relocatable_size_for_reloc): Remove.
	(Target_tilegx::gc_process_relocs): Use Default_classify_reloc.
	(Target_tilegx::scan_relocs): Likewise.
	(Target_tilegx::relocate_section): Likewise.
	(Target_tilegx::Relocatable_size_for_reloc::get_size_for_reloc):
	Remove.
	(Target_tilegx::scan_relocatable_relocs): Use Default_classify_reloc.
	(Target_tilegx::relocate_relocs): Use Default_classify_reloc.
	* x86_64.cc (Target_x86_64::emit_relocs_scan): New method.
	(Target_x86_64::Relocatable_size_for_reloc): Remove.
	(Target_x86_64::gc_process_relocs): Use Default_classify_reloc.
	(Target_x86_64::scan_relocs): Likewise.
	(Target_x86_64::relocate_section): Likewise.
	(Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc):
	Remove.
	(Target_x86_64::scan_relocatable_relocs): Use Default_classify_reloc.
	(Target_x86_64::relocate_relocs): Use Default_classify_reloc.

	* testsuite/testfile.cc (Target_test::emit_relocs_scan): New method.

1 files changed, 85 insertions, 22 deletions

diff --git a/gold/powerpc.cc b/gold/powerpc.cc
index b1c5aea..e26a198 100644
--- a/gold/powerpc.cc
+++ b/gold/powerpc.cc
@@ -663,6 +663,21 @@ class Target_powerpc : public Sized_target<size, big_endian>
 			  const unsigned char* plocal_symbols,
 			  Relocatable_relocs*);
 
+  // Scan the relocs for --emit-relocs.
+  void
+  emit_relocs_scan(Symbol_table* symtab,
+		   Layout* layout,
+		   Sized_relobj_file<size, big_endian>* object,
+		   unsigned int data_shndx,
+		   unsigned int sh_type,
+		   const unsigned char* prelocs,
+		   size_t reloc_count,
+		   Output_section* output_section,
+		   bool needs_special_offset_handling,
+		   size_t local_symbol_count,
+		   const unsigned char* plocal_syms,
+		   Relocatable_relocs* rr);
+
   // Emit relocations for a section.
   void
   relocate_relocs(const Relocate_info<size, big_endian>*,
@@ -1105,19 +1120,6 @@ class Target_powerpc : public Sized_target<size, big_endian>
     }
   };
 
-  // A class which returns the size required for a relocation type,
-  // used while scanning relocs during a relocatable link.
-  class Relocatable_size_for_reloc
-  {
-   public:
-    unsigned int
-    get_size_for_reloc(unsigned int, Relobj*)
-    {
-      gold_unreachable();
-      return 0;
-    }
-  };
-
   // Optimize the TLS relocation type based on what we know about the
   // symbol.  IS_FINAL is true if the final address of this symbol is
   // known at link time.
@@ -6430,7 +6432,9 @@ Target_powerpc<size, big_endian>::gc_process_relocs(
     const unsigned char* plocal_symbols)
 {
   typedef Target_powerpc<size, big_endian> Powerpc;
-  typedef typename Target_powerpc<size, big_endian>::Scan Scan;
+  typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, big_endian>
+      Classify_reloc;
+
   Powerpc_relobj<size, big_endian>* ppc_object
     = static_cast<Powerpc_relobj<size, big_endian>*>(object);
   if (size == 64)
@@ -6460,8 +6464,7 @@ Target_powerpc<size, big_endian>::gc_process_relocs(
       return;
     }
 
-  gold::gc_process_relocs<size, big_endian, Powerpc, elfcpp::SHT_RELA, Scan,
-			  typename Target_powerpc::Relocatable_size_for_reloc>(
+  gold::gc_process_relocs<size, big_endian, Powerpc, Scan, Classify_reloc>(
     symtab,
     layout,
     this,
@@ -6707,7 +6710,8 @@ Target_powerpc<size, big_endian>::scan_relocs(
     const unsigned char* plocal_symbols)
 {
   typedef Target_powerpc<size, big_endian> Powerpc;
-  typedef typename Target_powerpc<size, big_endian>::Scan Scan;
+  typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, big_endian>
+      Classify_reloc;
 
   if (sh_type == elfcpp::SHT_REL)
     {
@@ -6716,7 +6720,7 @@ Target_powerpc<size, big_endian>::scan_relocs(
       return;
     }
 
-  gold::scan_relocs<size, big_endian, Powerpc, elfcpp::SHT_RELA, Scan>(
+  gold::scan_relocs<size, big_endian, Powerpc, Scan, Classify_reloc>(
     symtab,
     layout,
     this,
@@ -8177,11 +8181,13 @@ Target_powerpc<size, big_endian>::relocate_section(
   typedef typename Target_powerpc<size, big_endian>::Relocate Powerpc_relocate;
   typedef typename Target_powerpc<size, big_endian>::Relocate_comdat_behavior
     Powerpc_comdat_behavior;
+  typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, big_endian>
+      Classify_reloc;
 
   gold_assert(sh_type == elfcpp::SHT_RELA);
 
-  gold::relocate_section<size, big_endian, Powerpc, elfcpp::SHT_RELA,
-			 Powerpc_relocate, Powerpc_comdat_behavior>(
+  gold::relocate_section<size, big_endian, Powerpc, Powerpc_relocate,
+			 Powerpc_comdat_behavior, Classify_reloc>(
     relinfo,
     this,
     prelocs,
@@ -8194,9 +8200,26 @@ Target_powerpc<size, big_endian>::relocate_section(
     reloc_symbol_changes);
 }
 
+template<int size, bool big_endian>
 class Powerpc_scan_relocatable_reloc
 {
 public:
+  typedef typename Reloc_types<elfcpp::SHT_RELA, size, big_endian>::Reloc
+      Reltype;
+  static const int reloc_size =
+      Reloc_types<elfcpp::SHT_RELA, size, big_endian>::reloc_size;
+  static const int sh_type = elfcpp::SHT_RELA;
+
+  // Return the symbol referred to by the relocation.
+  static inline unsigned int
+  get_r_sym(const Reltype* reloc)
+  { return elfcpp::elf_r_sym<size>(reloc->get_r_info()); }
+
+  // Return the type of the relocation.
+  static inline unsigned int
+  get_r_type(const Reltype* reloc)
+  { return elfcpp::elf_r_type<size>(reloc->get_r_info()); }
+
   // Return the strategy to use for a local symbol which is not a
   // section symbol, given the relocation type.
   inline Relocatable_relocs::Reloc_strategy
@@ -8244,10 +8267,11 @@ Target_powerpc<size, big_endian>::scan_relocatable_relocs(
     const unsigned char* plocal_symbols,
     Relocatable_relocs* rr)
 {
+  typedef Powerpc_scan_relocatable_reloc<size, big_endian> Scan_strategy;
+
   gold_assert(sh_type == elfcpp::SHT_RELA);
 
-  gold::scan_relocatable_relocs<size, big_endian, elfcpp::SHT_RELA,
-				Powerpc_scan_relocatable_reloc>(
+  gold::scan_relocatable_relocs<size, big_endian, Scan_strategy>(
     symtab,
     layout,
     object,
@@ -8261,6 +8285,45 @@ Target_powerpc<size, big_endian>::scan_relocatable_relocs(
     rr);
 }
 
+// Scan the relocs for --emit-relocs.
+
+template<int size, bool big_endian>
+void
+Target_powerpc<size, big_endian>::emit_relocs_scan(
+    Symbol_table* symtab,
+    Layout* layout,
+    Sized_relobj_file<size, big_endian>* object,
+    unsigned int data_shndx,
+    unsigned int sh_type,
+    const unsigned char* prelocs,
+    size_t reloc_count,
+    Output_section* output_section,
+    bool needs_special_offset_handling,
+    size_t local_symbol_count,
+    const unsigned char* plocal_syms,
+    Relocatable_relocs* rr)
+{
+  typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, big_endian>
+      Classify_reloc;
+  typedef gold::Default_emit_relocs_strategy<Classify_reloc>
+      Emit_relocs_strategy;
+
+  gold_assert(sh_type == elfcpp::SHT_RELA);
+
+  gold::scan_relocatable_relocs<size, big_endian, Emit_relocs_strategy>(
+    symtab,
+    layout,
+    object,
+    data_shndx,
+    prelocs,
+    reloc_count,
+    output_section,
+    needs_special_offset_handling,
+    local_symbol_count,
+    plocal_syms,
+    rr);
+}
+
 // Emit relocations for a section.
 // This is a modified version of the function by the same name in
 // target-reloc.h.  Using relocate_special_relocatable for