gold patch committed: Clean up FreeBSD handling

[Ian Lance Taylor <iant at google dot com>]

There has been some ugliness in gold for a while in that the i386 and
x86_64 targets inherit from the FreeBSD target.  This is really a
confusion of processor and OS, and involved a rather ugly function in
freebsd.h.  This patch cleans it up somewhat.  The Target_selector in
i386 and x86_64 still inherits from Target_selector_freebsd, but at
least Target_i386 and Target_x86_64 are cleaner.  Committed to mainline.

Ian


2011-06-28  Ian Lance Taylor  <iant@google.com>

	* target.h (class Target): Add osabi_ field.
	(Target::osabi): New function.
	(Target::set_osabi): New function.
	(Target::Target): Initialize osabi_.
	(Target::do_adjust_elf_header): Make pure virtual.
	(Sized_target::do_adjust_elf_header): Declare.
	* target.cc (Sized_target::do_adjust_elf_header): New function.
	(class Sized_target): Instantiate all versions.
	* freebsd.h (class Target_freebsd): Remove.
	(Target_selector_freebsd::do_recognize): Call set_osabi on
	Target.
	(Target_selector_freebsd::do_recognize_by_name): Likewise.
	(Target_selector_freebsd::set_osabi): Remove.
	* i386.cc (class Target_i386): Inherit from Sized_target rather
	than Target_freebsd.
	* x86_64.cc (class Target_x86_64): Likewise.


Index: freebsd.h
===================================================================
RCS file: /cvs/src/src/gold/freebsd.h,v
retrieving revision 1.4
diff -u -p -r1.4 freebsd.h
--- freebsd.h	14 Dec 2009 19:53:04 -0000	1.4
+++ freebsd.h	28 Jun 2011 22:21:46 -0000
@@ -1,6 +1,6 @@
 // freebsd.h -- FreeBSD support for gold    -*- C++ -*-
 
-// Copyright 2009 Free Software Foundation, Inc.
+// Copyright 2009, 2011 Free Software Foundation, Inc.
 // Written by Ian Lance Taylor <iant@google.com>.
 
 // This file is part of gold.
@@ -30,59 +30,8 @@ namespace gold
 {
 
 // FreeBSD 4.1 and later wants the EI_OSABI field in the ELF header to
-// be set to ELFOSABI_FREEBSD.  This is a subclass of Sized_target
-// which supports that.  The real target would be a subclass of this
-// one.  We permit combining FreeBSD and non-FreeBSD object files.
-// The effect of this target is to set the code in the output file.
-
-template<int size, bool big_endian>
-class Target_freebsd : public Sized_target<size, big_endian>
-{
- public:
-  // Set the value to use for the EI_OSABI field in the ELF header.
-  void
-  set_osabi(elfcpp::ELFOSABI osabi)
-  { this->osabi_ = osabi; }
-
- protected:
-  Target_freebsd(const Target::Target_info* pti)
-    : Sized_target<size, big_endian>(pti),
-      osabi_(elfcpp::ELFOSABI_NONE)
-  { }
-
-  virtual void
-  do_adjust_elf_header(unsigned char* view, int len) const;
-
- private:
-  // Value to store in the EI_OSABI field of the ELF file header.
-  elfcpp::ELFOSABI osabi_;
-};
-
-// Adjust the ELF file header by storing the requested value in the
-// OSABI field.  This is for FreeBSD support.
-
-template<int size, bool big_endian>
-inline void
-Target_freebsd<size, big_endian>::do_adjust_elf_header(unsigned char* view,
-						       int len) const
-{
-  if (this->osabi_ != elfcpp::ELFOSABI_NONE)
-    {
-      gold_assert(len == elfcpp::Elf_sizes<size>::ehdr_size);
-
-      elfcpp::Ehdr<size, false> ehdr(view);
-      unsigned char e_ident[elfcpp::EI_NIDENT];
-      memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
-
-      e_ident[elfcpp::EI_OSABI] = this->osabi_;
-
-      elfcpp::Ehdr_write<size, false> oehdr(view);
-      oehdr.put_e_ident(e_ident);
-    }
-}
-
-// A target selector for targets which permit combining both FreeBSD
-// and non-FreeBSD object files.
+// be set to ELFOSABI_FREEBSD.  This is a target selector for targets
+// which permit combining both FreeBSD and non-FreeBSD object files.
 
 class Target_selector_freebsd : public Target_selector
 {
@@ -102,7 +51,7 @@ class Target_selector_freebsd : public T
   {
     Target* ret = this->instantiate_target();
     if (osabi == elfcpp::ELFOSABI_FREEBSD)
-      this->set_osabi(ret);
+      ret->set_osabi(static_cast<elfcpp::ELFOSABI>(osabi));
     return ret;
   }
   
@@ -115,7 +64,7 @@ class Target_selector_freebsd : public T
     else if (strcmp(name, this->freebsd_bfd_name_) == 0)
       {
 	Target* ret = this->instantiate_target();
-	this->set_osabi(ret);
+	ret->set_osabi(elfcpp::ELFOSABI_FREEBSD);
 	return ret;
       }
     else
@@ -131,32 +80,6 @@ class Target_selector_freebsd : public T
   }
 
  private:
-  // Set the OSABI field.  This is quite ugly.
-  void
-  set_osabi(Target* target)
-  {
-    if (this->get_size() == 32)
-      {
-	if (this->is_big_endian())
-	  static_cast<Target_freebsd<32, true>*>(target)->
-	    set_osabi(elfcpp::ELFOSABI_FREEBSD);
-	else
-	  static_cast<Target_freebsd<32, false>*>(target)->
-	    set_osabi(elfcpp::ELFOSABI_FREEBSD);
-      }
-    else if (this->get_size() == 64)
-      {
-	if (this->is_big_endian())
-	  static_cast<Target_freebsd<64, true>*>(target)->
-	    set_osabi(elfcpp::ELFOSABI_FREEBSD);
-	else
-	  static_cast<Target_freebsd<64, false>*>(target)->
-	    set_osabi(elfcpp::ELFOSABI_FREEBSD);
-      }
-    else
-      gold_unreachable();
-  }
-
   // The BFD name for the non-Freebsd target.
   const char* bfd_name_;
   // The BFD name for the Freebsd target.
Index: i386.cc
===================================================================
RCS file: /cvs/src/src/gold/i386.cc,v
retrieving revision 1.129
diff -u -p -r1.129 i386.cc
--- i386.cc	28 Jun 2011 21:15:42 -0000	1.129
+++ i386.cc	28 Jun 2011 22:21:47 -0000
@@ -158,13 +158,13 @@ class Output_data_plt_i386 : public Outp
 //   http://people.redhat.com/drepper/tls.pdf
 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
 
-class Target_i386 : public Target_freebsd<32, false>
+class Target_i386 : public Sized_target<32, false>
 {
  public:
   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
 
   Target_i386()
-    : Target_freebsd<32, false>(&i386_info),
+    : Sized_target<32, false>(&i386_info),
       got_(NULL), plt_(NULL), got_plt_(NULL), got_tlsdesc_(NULL),
       global_offset_table_(NULL), rel_dyn_(NULL),
       copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
Index: target.cc
===================================================================
RCS file: /cvs/src/src/gold/target.cc,v
retrieving revision 1.10
diff -u -p -r1.10 target.cc
--- target.cc	24 May 2011 21:41:10 -0000	1.10
+++ target.cc	28 Jun 2011 22:21:47 -0000
@@ -1,6 +1,6 @@
-// target.cc
+// target.cc -- target support for gold.
 
-// Copyright 2009, 2010 Free Software Foundation, Inc.
+// Copyright 2009, 2010, 2011 Free Software Foundation, Inc.
 // Written by Doug Kwan <dougkwan@google.com>.
 
 // This file is part of gold.
@@ -200,4 +200,49 @@ Target::set_view_to_nop(unsigned char* v
     }
 }
 
+// Class Sized_target.
+
+// Set the EI_OSABI field of the ELF header if requested.
+
+template<int size, bool big_endian>
+void
+Sized_target<size, big_endian>::do_adjust_elf_header(unsigned char* view,
+						     int len) const
+{
+  elfcpp::ELFOSABI osabi = this->osabi();
+  if (osabi != elfcpp::ELFOSABI_NONE)
+    {
+      gold_assert(len == elfcpp::Elf_sizes<size>::ehdr_size);
+
+      elfcpp::Ehdr<size, false> ehdr(view);
+      unsigned char e_ident[elfcpp::EI_NIDENT];
+      memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
+
+      e_ident[elfcpp::EI_OSABI] = osabi;
+
+      elfcpp::Ehdr_write<size, false> oehdr(view);
+      oehdr.put_e_ident(e_ident);
+    }
+}
+
+#ifdef HAVE_TARGET_32_LITTLE
+template
+class Sized_target<32, false>;
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+class Sized_target<32, true>;
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+class Sized_target<64, false>;
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+class Sized_target<64, true>;
+#endif
+
 } // End namespace gold.
Index: target.h
===================================================================
RCS file: /cvs/src/src/gold/target.h,v
retrieving revision 1.59
diff -u -p -r1.59 target.h
--- target.h	28 Jun 2011 21:15:42 -0000	1.59
+++ target.h	28 Jun 2011 22:21:47 -0000
@@ -375,6 +375,17 @@ class Target
   select_as_default_target()
   { this->do_select_as_default_target(); } 
 
+  // Return the value to store in the EI_OSABI field in the ELF
+  // header.
+  elfcpp::ELFOSABI
+  osabi() const
+  { return this->osabi_; }
+
+  // Set the value to store in the EI_OSABI field in the ELF header.
+  void
+  set_osabi(elfcpp::ELFOSABI osabi)
+  { this->osabi_ = osabi; }
+
  protected:
   // This struct holds the constant information for a child class.  We
   // use a struct to avoid the overhead of virtual function calls for
@@ -427,7 +438,7 @@ class Target
 
   Target(const Target_info* pti)
     : pti_(pti), processor_specific_flags_(0),
-      are_processor_specific_flags_set_(false)
+      are_processor_specific_flags_set_(false), osabi_(elfcpp::ELFOSABI_NONE)
   { }
 
   // Virtual function which may be implemented by the child class.
@@ -459,10 +470,10 @@ class Target
   // Adjust the output file header before it is written out.  VIEW
   // points to the header in external form.  LEN is the length, and
   // will be one of the values of elfcpp::Elf_sizes<size>::ehdr_size.
-  // By default, we do nothing.
+  // By default, we set the EI_OSABI field if requested (in
+  // Sized_target).
   virtual void
-  do_adjust_elf_header(unsigned char*, int) const
-  { }
+  do_adjust_elf_header(unsigned char*, int) const = 0;
 
   // Virtual function which may be overridden by the child class.
   virtual bool
@@ -622,6 +633,10 @@ class Target
   elfcpp::Elf_Word processor_specific_flags_;
   // Whether the processor-specific flags are set at least once.
   bool are_processor_specific_flags_set_;
+  // If not ELFOSABI_NONE, the value to put in the EI_OSABI field of
+  // the ELF header.  This is handled at this level because it is
+  // OS-specific rather than processor-specific.
+  elfcpp::ELFOSABI osabi_;
 };
 
 // The abstract class for a specific size and endianness of target.
@@ -873,6 +888,10 @@ class Sized_target : public Target
     gold_assert(pti->size == size);
     gold_assert(pti->is_big_endian ? big_endian : !big_endian);
   }
+
+  // Set the EI_OSABI field if requested.
+  virtual void
+  do_adjust_elf_header(unsigned char*, int) const;
 };
 
 } // End namespace gold.
Index: x86_64.cc
===================================================================
RCS file: /cvs/src/src/gold/x86_64.cc,v
retrieving revision 1.128
diff -u -p -r1.128 x86_64.cc
--- x86_64.cc	28 Jun 2011 21:15:42 -0000	1.128
+++ x86_64.cc	28 Jun 2011 22:21:47 -0000
@@ -201,7 +201,7 @@ class Output_data_plt_x86_64 : public Ou
 //   http://people.redhat.com/drepper/tls.pdf
 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
 
-class Target_x86_64 : public Target_freebsd<64, false>
+class Target_x86_64 : public Sized_target<64, false>
 {
  public:
   // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
@@ -209,7 +209,7 @@ class Target_x86_64 : public Target_free
   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
 
   Target_x86_64()
-    : Target_freebsd<64, false>(&x86_64_info),
+    : Sized_target<64, false>(&x86_64_info),
       got_(NULL), plt_(NULL), got_plt_(NULL), got_tlsdesc_(NULL),
       global_offset_table_(NULL), rela_dyn_(NULL),
       copy_relocs_(elfcpp::R_X86_64_COPY), dynbss_(NULL),