From 89fc34211be8b1d74b83e4e2b18cfa4b4cf65ba9 Mon Sep 17 00:00:00 2001 From: Cary Coutant Date: Fri, 19 Sep 2008 22:54:57 +0000 Subject: 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. --- gold/descriptors.cc | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) (limited to 'gold/descriptors.cc') diff --git a/gold/descriptors.cc b/gold/descriptors.cc index 75a7a86..73c03bf 100644 --- a/gold/descriptors.cc +++ b/gold/descriptors.cc @@ -115,7 +115,9 @@ Descriptors::open(int descriptor, const char* name, int flags, int mode) pod->inuse = true; pod->is_write = (flags & O_ACCMODE) != O_RDONLY; - ++this->current_; + if (!pod->is_claimed) + ++this->current_; + pod->is_claimed = false; if (this->current_ >= this->limit_) this->close_some_descriptor(); @@ -166,6 +168,24 @@ Descriptors::release(int descriptor, bool permanent) } } +// Claim the file descriptor DESCRIPTOR for a plugin. This effectively +// removes the descriptor from the pool of linker-managed descriptors, +// as the plugin will assume responsibility for closing it. +// The IS_CLAIMED flag allows us to recognize when a file descriptor +// has been reused after being closed by the plugin. + +void +Descriptors::claim_for_plugin(int descriptor) +{ + Hold_lock hl(*this->lock_); + + gold_assert(descriptor >= 0 + && (static_cast(descriptor) + < this->open_descriptors_.size())); + Open_descriptor* pod = &this->open_descriptors_[descriptor]; + pod->is_claimed = true; +} + // Close some descriptor. The lock is held when this is called. We // close the descriptor on the top of the free stack. Note that this // is the opposite of an LRU algorithm--we close the most recently -- cgit v1.1