Add plugin functionality for link-time optimization (LTO).

include/:
	* plugin-api.h: New file.

gold/:
	* configure.ac (plugins): Add --enable-plugins option.
	* configure: Regenerate.
	* config.in: Regenerate.
	* Makefile.am (LIBDL): New variable.
	(CCFILES): Add plugin.cc.
	(HFILES): Add plugin.h.
	(ldadd_var): Add LIBDL.
	* Makefile.in: Regenerate.

	* archive.cc: Include "plugin.h".
	(Archive::setup): Don't preread archive symbols when using a plugin.
	(Archive::get_file_and_offset): Add memsize parameter.  Change callers.
	(Archive::get_elf_object_for_member): Call plugin hooks for claiming
	files.
	(Archive::include_member): Add symbols from plugin objects.
	* archive.h (Archive::get_file_and_offset): Add memsize parameter.
	* descriptors.cc (Descriptors::open): Check for file descriptors
	abandoned by plugins.
	(Descriptors::claim_for_plugin): New function.
	* descriptors.h (Descriptors::claim_for_plugin): New function.
	(Open_descriptor::is_claimed): New field.
	(claim_descriptor_for_plugin): New function.
	* fileread.cc (File_read::claim_for_plugin): New function.
	* fileread.h (File_read::claim_for_plugin): New function.
	(File_read::descriptor): New function.
	* gold.cc: Include "plugin.h".
	(queue_initial_tasks): Add task to call plugin hooks for generating
	new object files.
	* main.cc: Include "plugin.h".
	(main): Load plugin libraries.
	* object.h (Pluginobj): Declare.
	(Object::pluginobj): New function.
	(Object::do_pluginobj): New function.
	(Object::set_target): New function.
	* options.cc: Include "plugin.h".
	(General_options::parse_plugin): New function.
	(General_options::General_options): Initialize plugins_ field.
	(General_options::add_plugin): New function.
	* options.h (Plugin_manager): Declare.
	(General_options): Add --plugin option.
	(General_options::has_plugins): New function.
	(General_options::plugins): New function.
	(General_options::add_plugin): New function.
	(General_options::plugins_): New field.
	* plugin.cc: New file.
	* plugin.h: New file.
	* readsyms.cc: Include "plugin.h".
	(Read_symbols::do_read_symbols): Check for archive before checking
	for ELF file.  Call plugin hooks to claim files.
	* resolve.cc (Symbol_table::resolve): Record when symbol is referenced
	from a real object file; force override when processing replacement
	files.
	* symtab.cc (Symbol::init_fields): Initialize in_real_elf_ field.
	(Symbol::init_base_object): Likewise.
	(Symbol::init_base_output_data): Likewise.
	(Symbol::init_base_output_segment): Likewise.
	(Symbol::init_base_constant): Likewise.
	(Symbol::init_base_undefined): Likewise.
	(Symbol::output_section): Assert that object is not a plugin.
	(Symbol_table::add_from_pluginobj): New function.
	(Symbol_table::sized_finalize_symbol): Treat symbols from plugins as
	undefined.
	(Symbol_table::sized_write_globals): Likewise.
	(Symbol_table::add_from_pluginobj): Instantiate template.
	* symtab.h (Sized_pluginobj): Declare.
	(Symbol::in_real_elf): New function.
	(Symbol::set_in_real_elf): New function.
	(Symbol::in_real_elf_): New field.
	(Symbol_table::add_from_pluginobj): New function.

	* testsuite/Makefile.am (AM_CFLAGS): New variable.
	(LIBDL): New variable.
	(LDADD): Add LIBDL.
	(check_PROGRAMS): Add plugin_test_1 and plugin_test_2.
	(check_SCRIPTS): Add plugin_test_1.sh and plugin_test_2.sh.
	(check_DATA): Add plugin_test_1.err and plugin_test_2.err.
	(MOSTLYCLEANFILES): Likewise.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/plugin_test.c: New file.
	* testsuite/plugin_test_1.sh: New file.
	* testsuite/plugin_test_2.sh: New file.

1 files changed, 11 insertions, 3 deletions

diff --git a/gold/Makefile.in b/gold/Makefile.in
index bbc5417..f6a80d0 100644
--- a/gold/Makefile.in
+++ b/gold/Makefile.in
@@ -82,7 +82,7 @@ am__objects_1 = archive.$(OBJEXT) binary.$(OBJEXT) common.$(OBJEXT) \
 	fileread.$(OBJEXT) gold.$(OBJEXT) gold-threads.$(OBJEXT) \
 	layout.$(OBJEXT) mapfile.$(OBJEXT) merge.$(OBJEXT) \
 	object.$(OBJEXT) options.$(OBJEXT) output.$(OBJEXT) \
-	parameters.$(OBJEXT) readsyms.$(OBJEXT) \
+	parameters.$(OBJEXT) plugin.$(OBJEXT) readsyms.$(OBJEXT) \
 	reduced_debug_output.$(OBJEXT) reloc.$(OBJEXT) \
 	resolve.$(OBJEXT) script-sections.$(OBJEXT) script.$(OBJEXT) \
 	stringpool.$(OBJEXT) symtab.$(OBJEXT) target-select.$(OBJEXT) \
@@ -101,7 +101,7 @@ am__DEPENDENCIES_1 =
 am__DEPENDENCIES_2 = ../libiberty/libiberty.a
 am__DEPENDENCIES_3 = $(am__DEPENDENCIES_1) libgold.a \
 	$(am__DEPENDENCIES_2) $(am__DEPENDENCIES_1) \
-	$(am__DEPENDENCIES_1)
+	$(am__DEPENDENCIES_1) $(am__DEPENDENCIES_1)
 am__DEPENDENCIES_4 = @LIBOBJS@
 am__ld1_SOURCES_DIST = main.cc
 @GCC_TRUE@@NATIVE_LINKER_TRUE@am_ld1_OBJECTS = $(am__objects_4)
@@ -227,6 +227,8 @@ PACKAGE_STRING = @PACKAGE_STRING@
 PACKAGE_TARNAME = @PACKAGE_TARNAME@
 PACKAGE_VERSION = @PACKAGE_VERSION@
 PATH_SEPARATOR = @PATH_SEPARATOR@
+PLUGINS_FALSE = @PLUGINS_FALSE@
+PLUGINS_TRUE = @PLUGINS_TRUE@
 POSUB = @POSUB@
 RANDOM_SEED_CFLAGS = @RANDOM_SEED_CFLAGS@
 RANLIB = @RANLIB@
@@ -308,6 +310,7 @@ INCLUDES = \
 	@INCINTL@
 
 LIBIBERTY = ../libiberty/libiberty.a
+@PLUGINS_TRUE@LIBDL = -ldl
 @THREADS_TRUE@THREADSLIB = -lpthread
 AM_YFLAGS = -d
 noinst_LIBRARIES = libgold.a
@@ -336,6 +339,7 @@ CCFILES = \
 	options.cc \
 	output.cc \
 	parameters.cc \
+	plugin.cc \
 	readsyms.cc \
 	reduced_debug_output.cc \
 	reloc.cc \
@@ -373,6 +377,7 @@ HFILES = \
 	options.h \
 	output.h \
 	parameters.h \
+	plugin.h \
 	readsyms.h \
 	reduced_debug_output.h \
 	reloc.h \
@@ -403,7 +408,9 @@ ALL_TARGETOBJS = \
 libgold_a_SOURCES = $(CCFILES) $(HFILES) $(YFILES)
 sources_var = main.cc
 deps_var = $(TARGETOBJS) libgold.a $(LIBIBERTY) $(LIBINTL_DEP)
-ldadd_var = $(TARGETOBJS) libgold.a $(LIBIBERTY) $(LIBINTL) $(THREADSLIB)
+ldadd_var = $(TARGETOBJS) libgold.a $(LIBIBERTY) $(LIBINTL) \
+	 $(THREADSLIB) $(LIBDL)
+
 ld_new_SOURCES = $(sources_var)
 ld_new_DEPENDENCIES = $(deps_var) $(LIBOBJS)
 ld_new_LDADD = $(ldadd_var) $(LIBOBJS)
@@ -550,6 +557,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/options.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/output.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/parameters.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/plugin.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/powerpc.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/readsyms.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/reduced_debug_output.Po@am__quote@