2009-06-05 Doug Kwan <dougkwan@google.com>

	* Makefile.am (CCFILES): Add target.cc.
	* Makefile.in: Regenerate.
	* i386.cc (class Target_i386): Define new virtual method to
	override do_is_local_label_name in parent.
	* object.cc (Sized_relobj::do_count_local_symbols): Discard
	local symbols if --discard-locals or -X is given.
	* options.h (class General_options): Declare new options
	'--discard-locals' and '-X' for discarding locals.
	* target.h (class Target): Define new methods is_local_label_name.
	Declare new virtual method do_is_local_label_name.
	* target.cc: New file.
	* testsuite/Makefile.am (check_PROGRAMS): Add discard_locals_test.
	(check_SCRIPTS): Add discard_locals_test.sh.
	(check_DATA): Add discard_local_tests.syms.
	(discard_locals_test_SOURCES, discard_locals_test_LDFLAGS): Define.
	(discard_local_tests.syms, discard_locals_test.o): New make rules.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/discard_locals_test.c: New file.
	* testsuite/discard_locals_test.sh: Same.

1 files changed, 23 insertions, 1 deletions

diff --git a/gold/object.cc b/gold/object.cc
index 77ddce6..88b6028 100644
--- a/gold/object.cc
+++ b/gold/object.cc
@@ -1439,6 +1439,7 @@ Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
   unsigned int dyncount = 0;
   // Skip the first, dummy, symbol.
   psyms += sym_size;
+  bool discard_locals = parameters->options().discard_locals();
   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
     {
       elfcpp::Sym<size, big_endian> sym(psyms);
@@ -1484,8 +1485,29 @@ Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
 	  continue;
 	}
 
-      // Add the symbol to the symbol table string pool.
+      // If --discard-locals option is used, discard all temporary local
+      // symbols.  These symbols start with system-specific local label
+      // prefixes, typically .L for ELF system.  We want to be compatible
+      // with GNU ld so here we essentially use the same check in
+      // bfd_is_local_label().  The code is different because we already
+      // know that:
+      //
+      //   - the symbol is local and thus cannot have global or weak binding.
+      //   - the symbol is not a section symbol.
+      //   - the symbol has a name.
+      //
+      // We do not discard a symbol if it needs a dynamic symbol entry.
       const char* name = pnames + sym.get_st_name();
+      if (discard_locals
+	  && sym.get_st_type() != elfcpp::STT_FILE
+	  && !lv.needs_output_dynsym_entry()
+	  && parameters->target().is_local_label_name(name))
+	{
+	  lv.set_no_output_symtab_entry();
+	  continue;
+	}
+
+      // Add the symbol to the symbol table string pool.
       pool->add(name, true, NULL);
       ++count;