2009-05-28 Doug Kwan <dougkwan@google.com>

        * configure.ac: Support gold for target arm*-*-*.
        * configure: Regenerate.
        * gold/Makefile.am (TARGETSOURCES): Add arm.cc.
        (ALL_TARGETOBJECTS): Add arm.$(OBJEXT)
        * gold/Makefile.in: Regenerate.
        * gold/arm.cc: New file.
        * gold/configure.tgt: Add armbe*-*-*, armeb*-*-* and arm*-*-* targets.

1 files changed, 672 insertions, 0 deletions

diff --git a/gold/arm.cc b/gold/arm.cc
new file mode 100644
index 0000000..580b3ef
--- /dev/null
+++ b/gold/arm.cc
@@ -0,0 +1,672 @@
+// arm.cc -- arm target support for gold.
+
+// Copyright 2009 Free Software Foundation, Inc.
+// Written by Doug Kwan <dougkwan@google.com> based on the i386 code
+// by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#include "gold.h"
+
+#include <cstring>
+#include <limits>
+#include <cstdio>
+#include <string>
+
+#include "elfcpp.h"
+#include "parameters.h"
+#include "reloc.h"
+#include "arm.h"
+#include "object.h"
+#include "symtab.h"
+#include "layout.h"
+#include "output.h"
+#include "copy-relocs.h"
+#include "target.h"
+#include "target-reloc.h"
+#include "target-select.h"
+#include "tls.h"
+#include "defstd.h"
+
+namespace
+{
+
+using namespace gold;
+
+// The arm target class.
+//
+// This is a very simple port of gold for ARM-EABI.  It is intended for
+// supporting Android only for the time being.  Only these relocation types
+// are supported.
+//
+// R_ARM_NONE
+// R_ARM_ABS32
+// R_ARM_REL32
+// R_ARM_THM_CALL
+// R_ARM_COPY
+// R_ARM_GLOB_DAT
+// R_ARM_BASE_PREL
+// R_ARM_JUMP_SLOT
+// R_ARM_RELATIVE
+// R_ARM_GOTOFF32
+// R_ARM_GOT_BREL
+// R_ARM_PLT32
+// R_ARM_CALL
+// R_ARM_JUMP24
+// R_ARM_TARGET1
+// R_ARM_PREL31
+// 
+// Coming soon (pending patches):
+// - Support for dynamic symbols (GOT, PLT and etc).
+// - Local scanner
+// - Global scanner
+// - Relocation
+// - Defining section symbols __exidx_start and __exidx_stop.
+// - Support interworking.
+// - Mergeing all .ARM.xxx.yyy sections into .ARM.xxx.  Currently, they
+//   are incorrectly merged into an .ARM section.
+//
+// TODOs:
+// - Create a PT_ARM_EXIDX program header for a shared object that
+//   might throw an exception.
+// - Support more relocation types as needed. 
+
+template<bool big_endian>
+class Target_arm : public Sized_target<32, big_endian>
+{
+ public:
+  typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
+    Reloc_section;
+
+  Target_arm()
+    : Sized_target<32, big_endian>(&arm_info)
+  { }
+
+  // Process the relocations to determine unreferenced sections for 
+  // garbage collection.
+  void
+  gc_process_relocs(const General_options& options,
+		    Symbol_table* symtab,
+		    Layout* layout,
+		    Sized_relobj<32, 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_symbols);
+
+  // Scan the relocations to look for symbol adjustments.
+  void
+  scan_relocs(const General_options& options,
+	      Symbol_table* symtab,
+	      Layout* layout,
+	      Sized_relobj<32, 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_symbols);
+
+  // Finalize the sections.
+  void
+  do_finalize_sections(Layout*);
+
+  // Return the value to use for a dynamic which requires special
+  // treatment.
+  uint64_t
+  do_dynsym_value(const Symbol*) const;
+
+  // Relocate a section.
+  void
+  relocate_section(const Relocate_info<32, big_endian>*,
+		   unsigned int sh_type,
+		   const unsigned char* prelocs,
+		   size_t reloc_count,
+		   Output_section* output_section,
+		   bool needs_special_offset_handling,
+		   unsigned char* view,
+		   elfcpp::Elf_types<32>::Elf_Addr view_address,
+		   section_size_type view_size);
+
+  // Scan the relocs during a relocatable link.
+  void
+  scan_relocatable_relocs(const General_options& options,
+			  Symbol_table* symtab,
+			  Layout* layout,
+			  Sized_relobj<32, 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_symbols,
+			  Relocatable_relocs*);
+
+  // Relocate a section during a relocatable link.
+  void
+  relocate_for_relocatable(const Relocate_info<32, big_endian>*,
+			   unsigned int sh_type,
+			   const unsigned char* prelocs,
+			   size_t reloc_count,
+			   Output_section* output_section,
+			   off_t offset_in_output_section,
+			   const Relocatable_relocs*,
+			   unsigned char* view,
+			   elfcpp::Elf_types<32>::Elf_Addr view_address,
+			   section_size_type view_size,
+			   unsigned char* reloc_view,
+			   section_size_type reloc_view_size);
+
+  // Return whether SYM is defined by the ABI.
+  bool
+  do_is_defined_by_abi(Symbol* sym) const
+  { return strcmp(sym->name(), "__tls_get_addr") == 0; }
+
+  // Map platform-specific reloc types
+  static unsigned int
+  get_real_reloc_type (unsigned int r_type);
+
+ private:
+  // The class which scans relocations.
+  class Scan
+  {
+   public:
+    Scan()
+    { }
+
+    inline void
+    local(const General_options& options, Symbol_table* symtab,
+	  Layout* layout, Target_arm* target,
+	  Sized_relobj<32, big_endian>* object,
+	  unsigned int data_shndx,
+	  Output_section* output_section,
+	  const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
+	  const elfcpp::Sym<32, big_endian>& lsym);
+
+    inline void
+    global(const General_options& options, Symbol_table* symtab,
+	   Layout* layout, Target_arm* target,
+	   Sized_relobj<32, big_endian>* object,
+	   unsigned int data_shndx,
+	   Output_section* output_section,
+	   const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
+	   Symbol* gsym);
+
+   private:
+    static void
+    unsupported_reloc_local(Sized_relobj<32, big_endian>*,
+			    unsigned int r_type);
+
+    static void
+    unsupported_reloc_global(Sized_relobj<32, big_endian>*,
+			     unsigned int r_type, Symbol*);
+  };
+
+  // The class which implements relocation.
+  class Relocate
+  {
+   public:
+    Relocate()
+    { }
+
+    ~Relocate()
+    { }
+
+    // Do a relocation.  Return false if the caller should not issue
+    // any warnings about this relocation.
+    inline bool
+    relocate(const Relocate_info<32, big_endian>*, Target_arm*,
+	     Output_section*,  size_t relnum,
+	     const elfcpp::Rel<32, big_endian>&,
+	     unsigned int r_type, const Sized_symbol<32>*,
+	     const Symbol_value<32>*,
+	     unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
+	     section_size_type);
+  };
+
+  // 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*);
+  };
+
+  // Information about this specific target which we pass to the
+  // general Target structure.
+  static const Target::Target_info arm_info;
+};
+
+template<bool big_endian>
+const Target::Target_info Target_arm<big_endian>::arm_info =
+{
+  32,			// size
+  big_endian,		// is_big_endian
+  elfcpp::EM_ARM,	// machine_code
+  false,		// has_make_symbol
+  false,		// has_resolve
+  false,		// has_code_fill
+  true,			// is_default_stack_executable
+  '\0',			// wrap_char
+  "/usr/lib/libc.so.1",	// dynamic_linker
+  0x8000,		// default_text_segment_address
+  0x1000,		// abi_pagesize (overridable by -z max-page-size)
+  0x1000		// common_pagesize (overridable by -z common-page-size)
+};
+
+// Report an unsupported relocation against a local symbol.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::Scan::unsupported_reloc_local(
+    Sized_relobj<32, big_endian>* object,
+    unsigned int r_type)
+{
+  gold_error(_("%s: unsupported reloc %u against local symbol"),
+	     object->name().c_str(), r_type);
+}
+
+// Scan a relocation for a local symbol.
+
+template<bool big_endian>
+inline void
+Target_arm<big_endian>::Scan::local(const General_options&,
+				    Symbol_table* /* symtab */,
+				    Layout* /* layout */,
+				    Target_arm* /* target */,
+				    Sized_relobj<32, big_endian>* object,
+				    unsigned int /* data_shndx */,
+				    Output_section* /* output_section */,
+				    const elfcpp::Rel<32, big_endian>& /* reloc */,
+				    unsigned int r_type,
+				    const elfcpp::Sym<32, big_endian>&)
+{
+  r_type = get_real_reloc_type(r_type);
+  switch (r_type)
+    {
+    case elfcpp::R_ARM_NONE:
+      break;
+
+    default:
+      unsupported_reloc_local(object, r_type);
+      break;
+    }
+}
+
+// Report an unsupported relocation against a global symbol.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::Scan::unsupported_reloc_global(
+    Sized_relobj<32, big_endian>* object,
+    unsigned int r_type,
+    Symbol* gsym)
+{
+  gold_error(_("%s: unsupported reloc %u against global symbol %s"),
+	     object->name().c_str(), r_type, gsym->demangled_name().c_str());
+}
+
+// Scan a relocation for a global symbol.
+
+template<bool big_endian>
+inline void
+Target_arm<big_endian>::Scan::global(const General_options&,
+				     Symbol_table* /* symtab */,
+				     Layout* /* layout */,
+				     Target_arm* /* target */,
+				     Sized_relobj<32, big_endian>* object,
+				     unsigned int /* data_shndx */,
+				     Output_section* /* output_section */,
+				     const elfcpp::Rel<32, big_endian>& /* reloc */,
+				     unsigned int r_type,
+				     Symbol* gsym)
+{
+  r_type = get_real_reloc_type(r_type);
+  switch (r_type)
+    {
+    case elfcpp::R_ARM_NONE:
+      break;
+
+    default:
+      unsupported_reloc_global(object, r_type, gsym);
+      break;
+    }
+}
+
+// Process relocations for gc.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::gc_process_relocs(const General_options& options,
+					  Symbol_table* symtab,
+					  Layout* layout,
+					  Sized_relobj<32, big_endian>* object,
+					  unsigned int data_shndx,
+					  unsigned int,
+					  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_symbols)
+{
+  typedef Target_arm<big_endian> Arm;
+  typedef typename Target_arm<big_endian>::Scan Scan;
+
+  gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan>(
+    options,
+    symtab,
+    layout,
+    this,
+    object,
+    data_shndx,
+    prelocs,
+    reloc_count,
+    output_section,
+    needs_special_offset_handling,
+    local_symbol_count,
+    plocal_symbols);
+}
+
+// Scan relocations for a section.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::scan_relocs(const General_options& options,
+				    Symbol_table* symtab,
+				    Layout* layout,
+				    Sized_relobj<32, 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_symbols)
+{
+  typedef typename Target_arm<big_endian>::Scan Scan;
+  if (sh_type == elfcpp::SHT_RELA)
+    {
+      gold_error(_("%s: unsupported RELA reloc section"),
+		 object->name().c_str());
+      return;
+    }
+
+  gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
+    options,
+    symtab,
+    layout,
+    this,
+    object,
+    data_shndx,
+    prelocs,
+    reloc_count,
+    output_section,
+    needs_special_offset_handling,
+    local_symbol_count,
+    plocal_symbols);
+}
+
+// Finalize the sections.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::do_finalize_sections(Layout* /* layout */)
+{
+  gold_unreachable ();
+}
+
+// Perform a relocation.
+
+template<bool big_endian>
+inline bool
+Target_arm<big_endian>::Relocate::relocate(
+    const Relocate_info<32, big_endian>* /* relinfo */,
+    Target_arm* /* target */,
+    Output_section* /* output_section */,
+    size_t /* relnum */,
+    const elfcpp::Rel<32, big_endian>& /* rel */,
+    unsigned int r_type,
+    const Sized_symbol<32>* /* gsym */,
+    const Symbol_value<32>* /* psymval */,
+    unsigned char* /* view */,
+    elfcpp::Elf_types<32>::Elf_Addr /* address */,
+    section_size_type /* view_size */ )
+{
+  switch (r_type)
+    {
+    case elfcpp::R_ARM_NONE:
+      break;
+
+    default:
+      gold_unreachable();
+    }
+
+  return true;
+}
+
+// Relocate section data.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::relocate_section(
+    const Relocate_info<32, big_endian>* relinfo,
+    unsigned int sh_type,
+    const unsigned char* prelocs,
+    size_t reloc_count,
+    Output_section* output_section,
+    bool needs_special_offset_handling,
+    unsigned char* view,
+    elfcpp::Elf_types<32>::Elf_Addr address,
+    section_size_type view_size)
+{
+  typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
+  gold_assert(sh_type == elfcpp::SHT_REL);
+
+  gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
+			 Arm_relocate>(
+    relinfo,
+    this,
+    prelocs,
+    reloc_count,
+    output_section,
+    needs_special_offset_handling,
+    view,
+    address,
+    view_size);
+}
+
+// Return the size of a relocation while scanning during a relocatable
+// link.
+
+template<bool big_endian>
+unsigned int
+Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
+    unsigned int r_type,
+    Relobj* object)
+{
+  r_type = get_real_reloc_type(r_type);
+  switch (r_type)
+    {
+    case elfcpp::R_ARM_NONE:
+      return 0;
+
+    case elfcpp::R_ARM_ABS32:
+    case elfcpp::R_ARM_REL32:
+    case elfcpp::R_ARM_THM_CALL:
+    case elfcpp::R_ARM_GOTOFF32:
+    case elfcpp::R_ARM_BASE_PREL:
+    case elfcpp::R_ARM_GOT_BREL:
+    case elfcpp::R_ARM_PLT32:
+    case elfcpp::R_ARM_CALL:
+    case elfcpp::R_ARM_JUMP24:
+    case elfcpp::R_ARM_PREL31:
+      return 4;
+
+    case elfcpp::R_ARM_TARGET1:
+      // This should have been mapped to another type already.
+      // Fall through.
+    case elfcpp::R_ARM_COPY:
+    case elfcpp::R_ARM_GLOB_DAT:
+    case elfcpp::R_ARM_JUMP_SLOT:
+    case elfcpp::R_ARM_RELATIVE:
+      // These are relocations which should only be seen by the
+      // dynamic linker, and should never be seen here.
+      gold_error(_("%s: unexpected reloc %u in object file"),
+		 object->name().c_str(), r_type);
+      return 0;
+
+    default:
+      object->error(_("unsupported reloc %u in object file"), r_type);
+      return 0;
+    }
+}
+
+// Scan the relocs during a relocatable link.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::scan_relocatable_relocs(
+    const General_options& options,
+    Symbol_table* symtab,
+    Layout* layout,
+    Sized_relobj<32, 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_symbols,
+    Relocatable_relocs* rr)
+{
+  gold_assert(sh_type == elfcpp::SHT_REL);
+
+  typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
+    Relocatable_size_for_reloc> Scan_relocatable_relocs;
+
+  gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
+      Scan_relocatable_relocs>(
+    options,
+    symtab,
+    layout,
+    object,
+    data_shndx,
+    prelocs,
+    reloc_count,
+    output_section,
+    needs_special_offset_handling,
+    local_symbol_count,
+    plocal_symbols,
+    rr);
+}
+
+// Relocate a section during a relocatable link.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::relocate_for_relocatable(
+    const Relocate_info<32, big_endian>* relinfo,
+    unsigned int sh_type,
+    const unsigned char* prelocs,
+    size_t reloc_count,
+    Output_section* output_section,
+    off_t offset_in_output_section,
+    const Relocatable_relocs* rr,
+    unsigned char* view,
+    elfcpp::Elf_types<32>::Elf_Addr view_address,
+    section_size_type view_size,
+    unsigned char* reloc_view,
+    section_size_type reloc_view_size)
+{
+  gold_assert(sh_type == elfcpp::SHT_REL);
+
+  gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
+    relinfo,
+    prelocs,
+    reloc_count,
+    output_section,
+    offset_in_output_section,
+    rr,
+    view,
+    view_address,
+    view_size,
+    reloc_view,
+    reloc_view_size);
+}
+
+template<bool big_endian>
+uint64_t
+Target_arm<big_endian>::do_dynsym_value(const Symbol* /*gsym*/) const
+{
+  gold_unreachable ();
+  return 0;
+}
+
+// Map platform-specific relocs to real relocs
+//
+template<bool big_endian>
+unsigned int
+Target_arm<big_endian>::get_real_reloc_type (unsigned int r_type)
+{
+  switch (r_type)
+    {
+    case elfcpp::R_ARM_TARGET1:
+      // This is either R_ARM_ABS32 or R_ARM_REL32;
+      return elfcpp::R_ARM_ABS32;
+
+    case elfcpp::R_ARM_TARGET2:
+      // This can be any reloc type but ususally is R_ARM_GOT_PREL
+      return elfcpp::R_ARM_GOT_PREL;
+
+    default:
+      return r_type;
+    }
+}
+
+// The selector for arm object files.
+
+template<bool big_endian>
+class Target_selector_arm : public Target_selector
+{
+ public:
+  Target_selector_arm()
+    : Target_selector(elfcpp::EM_ARM, 32, big_endian,
+		      (big_endian ? "elf32-bigarm" : "elf32-littlearm"))
+  { }
+
+  Target*
+  do_instantiate_target()
+  { return new Target_arm<big_endian>(); }
+};
+
+Target_selector_arm<false> target_selector_arm;
+Target_selector_arm<true> target_selector_armbe;
+
+} // End anonymous namespace.