// gold.cc -- main linker functions
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright (C) 2006-2020 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include <cstdio>
#include <cstring>
#include <unistd.h>
+#include <algorithm>
#include "libiberty.h"
#include "options.h"
+#include "target-select.h"
+#include "debug.h"
#include "workqueue.h"
#include "dirsearch.h"
#include "readsyms.h"
#include "layout.h"
#include "reloc.h"
#include "defstd.h"
+#include "plugin.h"
+#include "gc.h"
+#include "icf.h"
+#include "incremental.h"
+#include "timer.h"
namespace gold
{
+class Object;
+
const char* program_name;
+static Task*
+process_incremental_input(Incremental_binary*, unsigned int, Input_objects*,
+ Symbol_table*, Layout*, Dirsearch*, Mapfile*,
+ Task_token*, Task_token*);
+
void
-gold_exit(bool status)
+gold_exit(Exit_status status)
{
- if (!status && parameters != NULL)
- unlink_if_ordinary(parameters->output_file_name());
- exit(status ? EXIT_SUCCESS : EXIT_FAILURE);
+ if (parameters != NULL
+ && parameters->options_valid()
+ && parameters->options().has_plugins())
+ parameters->options().plugins()->cleanup();
+ if (status != GOLD_OK && parameters != NULL && parameters->options_valid())
+ unlink_if_ordinary(parameters->options().output_file_name());
+ exit(status);
}
void
// We are out of memory, so try hard to print a reasonable message.
// Note that we don't try to translate this message, since the
// translation process itself will require memory.
- write(2, program_name, strlen(program_name));
- const char* const s = ": out of memory\n";
- write(2, s, strlen(s));
- gold_exit(false);
+
+ // LEN only exists to avoid a pointless warning when write is
+ // declared with warn_use_result, as when compiling with
+ // -D_USE_FORTIFY on GNU/Linux. Casting to void does not appear to
+ // work, at least not with gcc 4.3.0.
+
+ ssize_t len = write(2, program_name, strlen(program_name));
+ if (len >= 0)
+ {
+ const char* const s = ": out of memory\n";
+ len = write(2, s, strlen(s));
+ }
+ gold_exit(GOLD_ERR);
}
// Handle an unreachable case.
{
fprintf(stderr, _("%s: internal error in %s, at %s:%d\n"),
program_name, function, filename, lineno);
- gold_exit(false);
+ gold_exit(GOLD_ERR);
}
// This class arranges to run the functions done in the middle of the
Middle_runner(const General_options& options,
const Input_objects* input_objects,
Symbol_table* symtab,
- Layout* layout)
+ Layout* layout, Mapfile* mapfile)
: options_(options), input_objects_(input_objects), symtab_(symtab),
- layout_(layout)
+ layout_(layout), mapfile_(mapfile)
{ }
void
- run(Workqueue*);
+ run(Workqueue*, const Task*);
+
+ private:
+ const General_options& options_;
+ const Input_objects* input_objects_;
+ Symbol_table* symtab_;
+ Layout* layout_;
+ Mapfile* mapfile_;
+};
+
+void
+Middle_runner::run(Workqueue* workqueue, const Task* task)
+{
+ queue_middle_tasks(this->options_, task, this->input_objects_, this->symtab_,
+ this->layout_, workqueue, this->mapfile_);
+}
+
+// This class arranges the tasks to process the relocs for garbage collection.
+
+class Gc_runner : public Task_function_runner
+{
+ public:
+ Gc_runner(const General_options& options,
+ const Input_objects* input_objects,
+ Symbol_table* symtab,
+ Layout* layout, Mapfile* mapfile)
+ : options_(options), input_objects_(input_objects), symtab_(symtab),
+ layout_(layout), mapfile_(mapfile)
+ { }
+
+ void
+ run(Workqueue*, const Task*);
private:
const General_options& options_;
const Input_objects* input_objects_;
Symbol_table* symtab_;
Layout* layout_;
+ Mapfile* mapfile_;
};
void
-Middle_runner::run(Workqueue* workqueue)
+Gc_runner::run(Workqueue* workqueue, const Task* task)
{
- queue_middle_tasks(this->options_, this->input_objects_, this->symtab_,
- this->layout_, workqueue);
+ queue_middle_gc_tasks(this->options_, task, this->input_objects_,
+ this->symtab_, this->layout_, workqueue,
+ this->mapfile_);
}
// Queue up the initial set of tasks for this link job.
void
queue_initial_tasks(const General_options& options,
- const Dirsearch& search_path,
+ Dirsearch& search_path,
const Command_line& cmdline,
Workqueue* workqueue, Input_objects* input_objects,
- Symbol_table* symtab, Layout* layout)
+ Symbol_table* symtab, Layout* layout, Mapfile* mapfile)
{
- if (cmdline.begin() == cmdline.end())
- gold_fatal(_("no input files"));
+ if (cmdline.number_of_input_files() == 0)
+ {
+ bool is_ok = false;
+ if (options.printed_version())
+ is_ok = true;
+ if (options.print_output_format())
+ {
+ print_output_format();
+ is_ok = true;
+ }
+ if (is_ok)
+ gold_exit(GOLD_OK);
+ gold_fatal(_("no input files"));
+ }
int thread_count = options.thread_count_initial();
if (thread_count == 0)
thread_count = cmdline.number_of_input_files();
workqueue->set_thread_count(thread_count);
+ // For incremental links, the base output file.
+ Incremental_binary* ibase = NULL;
+
+ if (parameters->incremental_update())
+ {
+ Output_file* of = new Output_file(options.output_file_name());
+ if (of->open_base_file(options.incremental_base(), true))
+ {
+ ibase = open_incremental_binary(of);
+ if (ibase != NULL
+ && ibase->check_inputs(cmdline, layout->incremental_inputs()))
+ ibase->init_layout(layout);
+ else
+ {
+ delete ibase;
+ ibase = NULL;
+ of->close();
+ }
+ }
+ if (ibase == NULL)
+ {
+ if (set_parameters_incremental_full())
+ gold_info(_("linking with --incremental-full"));
+ else
+ gold_fallback(_("restart link with --incremental-full"));
+ }
+ }
+
// Read the input files. We have to add the symbols to the symbol
// table in order. We do this by creating a separate blocker for
// each input file. We associate the blocker with the following
// input file, to give us a convenient place to delete it.
Task_token* this_blocker = NULL;
- for (Command_line::const_iterator p = cmdline.begin();
- p != cmdline.end();
+ if (ibase == NULL)
+ {
+ // Normal link. Queue a Read_symbols task for each input file
+ // on the command line.
+ for (Command_line::const_iterator p = cmdline.begin();
+ p != cmdline.end();
+ ++p)
+ {
+ Task_token* next_blocker = new Task_token(true);
+ next_blocker->add_blocker();
+ workqueue->queue(new Read_symbols(input_objects, symtab, layout,
+ &search_path, 0, mapfile, &*p, NULL,
+ NULL, this_blocker, next_blocker));
+ this_blocker = next_blocker;
+ }
+ }
+ else
+ {
+ // Incremental update link. Process the list of input files
+ // stored in the base file, and queue a task for each file:
+ // a Read_symbols task for a changed file, and an Add_symbols task
+ // for an unchanged file. We need to mark all the space used by
+ // unchanged files before we can start any tasks running.
+ unsigned int input_file_count = ibase->input_file_count();
+ std::vector<Task*> tasks;
+ tasks.reserve(input_file_count);
+ for (unsigned int i = 0; i < input_file_count; ++i)
+ {
+ Task_token* next_blocker = new Task_token(true);
+ next_blocker->add_blocker();
+ Task* t = process_incremental_input(ibase, i, input_objects, symtab,
+ layout, &search_path, mapfile,
+ this_blocker, next_blocker);
+ tasks.push_back(t);
+ this_blocker = next_blocker;
+ }
+ // Now we can queue the tasks.
+ for (unsigned int i = 0; i < tasks.size(); i++)
+ workqueue->queue(tasks[i]);
+ }
+
+ if (options.has_plugins())
+ {
+ Task_token* next_blocker = new Task_token(true);
+ next_blocker->add_blocker();
+ workqueue->queue(new Plugin_hook(options, input_objects, symtab, layout,
+ &search_path, mapfile, this_blocker,
+ next_blocker));
+ this_blocker = next_blocker;
+ }
+
+ if (options.relocatable()
+ && (options.gc_sections() || options.icf_enabled()))
+ gold_error(_("cannot mix -r with --gc-sections or --icf"));
+
+ if (options.gc_sections() || options.icf_enabled())
+ {
+ workqueue->queue(new Task_function(new Gc_runner(options,
+ input_objects,
+ symtab,
+ layout,
+ mapfile),
+ this_blocker,
+ "Task_function Gc_runner"));
+ }
+ else
+ {
+ workqueue->queue(new Task_function(new Middle_runner(options,
+ input_objects,
+ symtab,
+ layout,
+ mapfile),
+ this_blocker,
+ "Task_function Middle_runner"));
+ }
+}
+
+// Process an incremental input file: if it is unchanged from the previous
+// link, return a task to add its symbols from the base file's incremental
+// info; if it has changed, return a normal Read_symbols task. We create a
+// task for every input file, if only to report the file for rebuilding the
+// incremental info.
+
+static Task*
+process_incremental_input(Incremental_binary* ibase,
+ unsigned int input_file_index,
+ Input_objects* input_objects,
+ Symbol_table* symtab,
+ Layout* layout,
+ Dirsearch* search_path,
+ Mapfile* mapfile,
+ Task_token* this_blocker,
+ Task_token* next_blocker)
+{
+ const Incremental_binary::Input_reader* input_reader =
+ ibase->get_input_reader(input_file_index);
+ Incremental_input_type input_type = input_reader->type();
+
+ // Get the input argument corresponding to this input file, matching on
+ // the argument serial number. If the input file cannot be matched
+ // to an existing input argument, synthesize a new one.
+ const Input_argument* input_argument =
+ ibase->get_input_argument(input_file_index);
+ if (input_argument == NULL)
+ {
+ Input_file_argument file(input_reader->filename(),
+ Input_file_argument::INPUT_FILE_TYPE_FILE,
+ "", false, parameters->options());
+ Input_argument* arg = new Input_argument(file);
+ arg->set_script_info(ibase->get_script_info(input_file_index));
+ input_argument = arg;
+ }
+
+ gold_debug(DEBUG_INCREMENTAL, "Incremental object: %s, type %d",
+ input_reader->filename(), input_type);
+
+ if (input_type == INCREMENTAL_INPUT_SCRIPT)
+ {
+ // Incremental_binary::check_inputs should have cancelled the
+ // incremental update if the script has changed.
+ gold_assert(!ibase->file_has_changed(input_file_index));
+ return new Check_script(layout, ibase, input_file_index, input_reader,
+ this_blocker, next_blocker);
+ }
+
+ if (input_type == INCREMENTAL_INPUT_ARCHIVE)
+ {
+ Incremental_library* lib = ibase->get_library(input_file_index);
+ gold_assert(lib != NULL);
+ if (lib->filename() == "/group/"
+ || !ibase->file_has_changed(input_file_index))
+ {
+ // Queue a task to check that no references have been added to any
+ // of the library's unused symbols.
+ return new Check_library(symtab, layout, ibase, input_file_index,
+ input_reader, this_blocker, next_blocker);
+ }
+ else
+ {
+ // Queue a Read_symbols task to process the archive normally.
+ return new Read_symbols(input_objects, symtab, layout, search_path,
+ 0, mapfile, input_argument, NULL, NULL,
+ this_blocker, next_blocker);
+ }
+ }
+
+ if (input_type == INCREMENTAL_INPUT_ARCHIVE_MEMBER)
+ {
+ // For archive members, check the timestamp of the containing archive.
+ Incremental_library* lib = ibase->get_library(input_file_index);
+ gold_assert(lib != NULL);
+ // Process members of a --start-lib/--end-lib group as normal objects.
+ if (lib->filename() != "/group/")
+ {
+ if (ibase->file_has_changed(lib->input_file_index()))
+ {
+ return new Read_member(input_objects, symtab, layout, mapfile,
+ input_reader, this_blocker, next_blocker);
+ }
+ else
+ {
+ // The previous contributions from this file will be kept.
+ // Mark the pieces of output sections contributed by this
+ // object.
+ ibase->reserve_layout(input_file_index);
+ Object* obj = make_sized_incremental_object(ibase,
+ input_file_index,
+ input_type,
+ input_reader);
+ return new Add_symbols(input_objects, symtab, layout,
+ search_path, 0, mapfile, input_argument,
+ obj, lib, NULL, this_blocker,
+ next_blocker);
+ }
+ }
+ }
+
+ // Normal object file or shared library. Check if the file has changed
+ // since the last incremental link.
+ if (ibase->file_has_changed(input_file_index))
+ {
+ return new Read_symbols(input_objects, symtab, layout, search_path, 0,
+ mapfile, input_argument, NULL, NULL,
+ this_blocker, next_blocker);
+ }
+ else
+ {
+ // The previous contributions from this file will be kept.
+ // Mark the pieces of output sections contributed by this object.
+ ibase->reserve_layout(input_file_index);
+ Object* obj = make_sized_incremental_object(ibase,
+ input_file_index,
+ input_type,
+ input_reader);
+ return new Add_symbols(input_objects, symtab, layout, search_path, 0,
+ mapfile, input_argument, obj, NULL, NULL,
+ this_blocker, next_blocker);
+ }
+}
+
+// Queue up a set of tasks to be done before queueing the middle set
+// of tasks. This is only necessary when garbage collection
+// (--gc-sections) of unused sections is desired. The relocs are read
+// and processed here early to determine the garbage sections before the
+// relocs can be scanned in later tasks.
+
+void
+queue_middle_gc_tasks(const General_options& options,
+ const Task* ,
+ const Input_objects* input_objects,
+ Symbol_table* symtab,
+ Layout* layout,
+ Workqueue* workqueue,
+ Mapfile* mapfile)
+{
+ // Read_relocs for all the objects must be done and processed to find
+ // unused sections before any scanning of the relocs can take place.
+ Task_token* this_blocker = NULL;
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
++p)
{
- Task_token* next_blocker = new Task_token();
+ Task_token* next_blocker = new Task_token(true);
next_blocker->add_blocker();
- workqueue->queue(new Read_symbols(options, input_objects, symtab, layout,
- search_path, &*p, NULL, this_blocker,
- next_blocker));
+ workqueue->queue(new Read_relocs(symtab, layout, *p, this_blocker,
+ next_blocker));
this_blocker = next_blocker;
}
+ // If we are given only archives in input, we have no regular
+ // objects and THIS_BLOCKER is NULL here. Create a dummy
+ // blocker here so that we can run the middle tasks immediately.
+ if (this_blocker == NULL)
+ {
+ gold_assert(input_objects->number_of_relobjs() == 0);
+ this_blocker = new Task_token(true);
+ }
+
workqueue->queue(new Task_function(new Middle_runner(options,
input_objects,
symtab,
- layout),
- this_blocker));
+ layout,
+ mapfile),
+ this_blocker,
+ "Task_function Middle_runner"));
}
// Queue up the middle set of tasks. These are the tasks which run
void
queue_middle_tasks(const General_options& options,
+ const Task* task,
const Input_objects* input_objects,
Symbol_table* symtab,
Layout* layout,
- Workqueue* workqueue)
+ Workqueue* workqueue,
+ Mapfile* mapfile)
{
- if (input_objects->number_of_input_objects() == 0)
+ Timer* timer = parameters->timer();
+ if (timer != NULL)
+ timer->stamp(0);
+
+ // We have to support the case of not seeing any input objects, and
+ // generate an empty file. Existing builds depend on being able to
+ // pass an empty archive to the linker and get an empty object file
+ // out. In order to do this we need to use a default target.
+ if (input_objects->number_of_input_objects() == 0
+ && layout->incremental_base() == NULL)
+ parameters_force_valid_target();
+
+ // Add any symbols named with -u options to the symbol table.
+ symtab->add_undefined_symbols_from_command_line(layout);
+
+ // If garbage collection was chosen, relocs have been read and processed
+ // at this point by pre_middle_tasks. Layout can then be done for all
+ // objects.
+ if (parameters->options().gc_sections())
{
- // We had some input files, but we weren't able to open any of
- // them.
- gold_fatal(_("no input files"));
+ // Find the start symbol if any.
+ Symbol* sym = symtab->lookup(parameters->entry());
+ if (sym != NULL)
+ symtab->gc_mark_symbol(sym);
+ sym = symtab->lookup(parameters->options().init());
+ if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
+ symtab->gc_mark_symbol(sym);
+ sym = symtab->lookup(parameters->options().fini());
+ if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
+ symtab->gc_mark_symbol(sym);
+ // Symbols named with -u should not be considered garbage.
+ symtab->gc_mark_undef_symbols(layout);
+ gold_assert(symtab->gc() != NULL);
+ // Do a transitive closure on all references to determine the worklist.
+ symtab->gc()->do_transitive_closure();
+ }
+
+ // If identical code folding (--icf) is chosen it makes sense to do it
+ // only after garbage collection (--gc-sections) as we do not want to
+ // be folding sections that will be garbage.
+ if (parameters->options().icf_enabled())
+ {
+ symtab->icf()->find_identical_sections(input_objects, symtab);
+ }
+
+ // Call Object::layout for the second time to determine the
+ // output_sections for all referenced input sections. When
+ // --gc-sections or --icf is turned on, or when certain input
+ // sections have to be mapped to unique segments, Object::layout
+ // is called twice. It is called the first time when symbols
+ // are added.
+ if (parameters->options().gc_sections()
+ || parameters->options().icf_enabled()
+ || layout->is_unique_segment_for_sections_specified())
+ {
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ Task_lock_obj<Object> tlo(task, *p);
+ (*p)->layout(symtab, layout, NULL);
+ }
+ }
+
+ // Layout deferred objects due to plugins.
+ if (parameters->options().has_plugins())
+ {
+ Plugin_manager* plugins = parameters->options().plugins();
+ gold_assert(plugins != NULL);
+ plugins->layout_deferred_objects();
+ }
+
+ // Finalize the .eh_frame section.
+ layout->finalize_eh_frame_section();
+
+ /* If plugins have specified a section order, re-arrange input sections
+ according to a specified section order. If --section-ordering-file is
+ also specified, do not do anything here. */
+ if (parameters->options().has_plugins()
+ && layout->is_section_ordering_specified()
+ && !parameters->options().section_ordering_file ())
+ {
+ for (Layout::Section_list::const_iterator p
+ = layout->section_list().begin();
+ p != layout->section_list().end();
+ ++p)
+ (*p)->update_section_layout(layout->get_section_order_map());
+ }
+
+ if (parameters->options().gc_sections()
+ || parameters->options().icf_enabled())
+ {
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ // Update the value of output_section stored in rd.
+ Read_relocs_data* rd = (*p)->get_relocs_data();
+ for (Read_relocs_data::Relocs_list::iterator q = rd->relocs.begin();
+ q != rd->relocs.end();
+ ++q)
+ {
+ q->output_section = (*p)->output_section(q->data_shndx);
+ q->needs_special_offset_handling =
+ (*p)->is_output_section_offset_invalid(q->data_shndx);
+ }
+ }
}
int thread_count = options.thread_count_middle();
if (thread_count == 0)
- thread_count = input_objects->number_of_input_objects();
+ thread_count = std::max(2, input_objects->number_of_input_objects());
workqueue->set_thread_count(thread_count);
// Now we have seen all the input files.
- const bool doing_static_link = (!input_objects->any_dynamic()
- && !parameters->output_is_shared());
+ const bool doing_static_link =
+ (!input_objects->any_dynamic()
+ && !parameters->options().output_is_position_independent());
set_parameters_doing_static_link(doing_static_link);
if (!doing_static_link && options.is_static())
{
// We print out just the first .so we see; there may be others.
+ gold_assert(input_objects->dynobj_begin() != input_objects->dynobj_end());
gold_error(_("cannot mix -static with dynamic object %s"),
(*input_objects->dynobj_begin())->name().c_str());
}
+ if (!doing_static_link && parameters->options().relocatable())
+ gold_fatal(_("cannot mix -r with dynamic object %s"),
+ (*input_objects->dynobj_begin())->name().c_str());
+ if (!doing_static_link
+ && options.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
+ gold_fatal(_("cannot use non-ELF output format with dynamic object %s"),
+ (*input_objects->dynobj_begin())->name().c_str());
+
+ if (parameters->options().relocatable())
+ {
+ Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ if (p != input_objects->relobj_end())
+ {
+ bool uses_split_stack = (*p)->uses_split_stack();
+ for (++p; p != input_objects->relobj_end(); ++p)
+ {
+ if ((*p)->uses_split_stack() != uses_split_stack)
+ {
+ const char *name1
+ = (*input_objects->relobj_begin())->name().c_str();
+ const char *name2 = (*p)->name().c_str();
+ const char *name_split = uses_split_stack ? name1 : name2;
+ const char *name_nosplit = uses_split_stack ? name2 : name1;
+ gold_fatal(_("cannot mix split-stack '%s' and "
+ "non-split-stack '%s' when using -r"),
+ name_split, name_nosplit);
+ }
+ }
+ }
+ }
+
+ // For incremental updates, record the existing GOT and PLT entries,
+ // and the COPY relocations.
+ if (parameters->incremental_update())
+ {
+ Incremental_binary* ibase = layout->incremental_base();
+ ibase->process_got_plt(symtab, layout);
+ ibase->emit_copy_relocs(symtab);
+ }
- // See if any of the input definitions violate the One Definition Rule.
- // TODO: if this is too slow, do this as a task, rather than inline.
- symtab->detect_odr_violations();
+ if (is_debugging_enabled(DEBUG_SCRIPT))
+ layout->script_options()->print(stderr);
+
+ // For each dynamic object, record whether we've seen all the
+ // dynamic objects that it depends upon.
+ input_objects->check_dynamic_dependencies();
+
+ // Do the --no-undefined-version check.
+ if (!parameters->options().undefined_version())
+ {
+ Script_options* so = layout->script_options();
+ so->version_script_info()->check_unmatched_names(symtab);
+ }
+
+ // Create any automatic note sections.
+ layout->create_notes();
+
+ // Create any output sections required by any linker script.
+ layout->create_script_sections();
// Define some sections and symbols needed for a dynamic link. This
// handles some cases we want to see before we read the relocs.
- layout->create_initial_dynamic_sections(input_objects, symtab);
-
- // Predefine standard symbols. This should be fast, so we don't
- // bother to create a task for it.
- define_standard_symbols(symtab, layout, input_objects->target());
-
- // Define __start and __stop symbols for output sections where
- // appropriate.
- layout->define_section_symbols(symtab, input_objects->target());
-
- // Read the relocations of the input files. We do this to find
- // which symbols are used by relocations which require a GOT and/or
- // a PLT entry, or a COPY reloc. When we implement garbage
- // collection we will do it here by reading the relocations in a
- // breadth first search by references.
- //
- // We could also read the relocations during the first pass, and
- // mark symbols at that time. That is how the old GNU linker works.
- // Doing that is more complex, since we may later decide to discard
- // some of the sections, and thus change our minds about the types
- // of references made to the symbols.
- Task_token* blocker = new Task_token();
- Task_token* symtab_lock = new Task_token();
- for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
- p != input_objects->relobj_end();
- ++p)
+ layout->create_initial_dynamic_sections(symtab);
+
+ // Define symbols from any linker scripts.
+ layout->define_script_symbols(symtab);
+
+ // TODO(csilvers): figure out a more principled way to get the target
+ Target* target = const_cast<Target*>(¶meters->target());
+
+ // Attach sections to segments.
+ layout->attach_sections_to_segments(target);
+
+ if (!parameters->options().relocatable())
+ {
+ // Predefine standard symbols.
+ define_standard_symbols(symtab, layout);
+
+ // Define __start and __stop symbols for output sections where
+ // appropriate.
+ layout->define_section_symbols(symtab);
+
+ // Define target-specific symbols.
+ target->define_standard_symbols(symtab, layout);
+ }
+
+ // Make sure we have symbols for any required group signatures.
+ layout->define_group_signatures(symtab);
+
+ Task_token* this_blocker = NULL;
+
+ // Allocate common symbols. We use a blocker to run this before the
+ // Scan_relocs tasks, because it writes to the symbol table just as
+ // they do.
+ if (parameters->options().define_common())
+ {
+ this_blocker = new Task_token(true);
+ this_blocker->add_blocker();
+ workqueue->queue(new Allocate_commons_task(symtab, layout, mapfile,
+ this_blocker));
+ }
+
+ // If doing garbage collection, the relocations have already been read.
+ // Otherwise, read and scan the relocations.
+ if (parameters->options().gc_sections()
+ || parameters->options().icf_enabled())
+ {
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ Task_token* next_blocker = new Task_token(true);
+ next_blocker->add_blocker();
+ workqueue->queue(new Scan_relocs(symtab, layout, *p,
+ (*p)->get_relocs_data(),
+ this_blocker, next_blocker));
+ this_blocker = next_blocker;
+ }
+ }
+ else
{
- // We can read and process the relocations in any order. But we
- // only want one task to write to the symbol table at a time.
- // So we queue up a task for each object to read the
- // relocations. That task will in turn queue a task to wait
- // until it can write to the symbol table.
- blocker->add_blocker();
- workqueue->queue(new Read_relocs(options, symtab, layout, *p,
- symtab_lock, blocker));
+ // Read the relocations of the input files. We do this to find
+ // which symbols are used by relocations which require a GOT and/or
+ // a PLT entry, or a COPY reloc. When we implement garbage
+ // collection we will do it here by reading the relocations in a
+ // breadth first search by references.
+ //
+ // We could also read the relocations during the first pass, and
+ // mark symbols at that time. That is how the old GNU linker works.
+ // Doing that is more complex, since we may later decide to discard
+ // some of the sections, and thus change our minds about the types
+ // of references made to the symbols.
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ Task_token* next_blocker = new Task_token(true);
+ next_blocker->add_blocker();
+ workqueue->queue(new Read_relocs(symtab, layout, *p, this_blocker,
+ next_blocker));
+ this_blocker = next_blocker;
+ }
}
- // Allocate common symbols. This requires write access to the
- // symbol table, but is independent of the relocation processing.
- blocker->add_blocker();
- workqueue->queue(new Allocate_commons_task(options, symtab, layout,
- symtab_lock, blocker));
+ if (this_blocker == NULL)
+ {
+ if (input_objects->number_of_relobjs() == 0)
+ {
+ // If we are given only archives in input, we have no regular
+ // objects and THIS_BLOCKER is NULL here. Create a dummy
+ // blocker here so that we can run the layout task immediately.
+ this_blocker = new Task_token(true);
+ }
+ else
+ {
+ // If we failed to open any input files, it's possible for
+ // THIS_BLOCKER to be NULL here. There's no real point in
+ // continuing if that happens.
+ gold_assert(parameters->errors()->error_count() > 0);
+ gold_exit(GOLD_ERR);
+ }
+ }
// When all those tasks are complete, we can start laying out the
// output file.
workqueue->queue(new Task_function(new Layout_task_runner(options,
input_objects,
symtab,
- layout),
- blocker));
+ target,
+ layout,
+ mapfile),
+ this_blocker,
+ "Task_function Layout_task_runner"));
}
// Queue up the final set of tasks. This is called at the end of
queue_final_tasks(const General_options& options,
const Input_objects* input_objects,
const Symbol_table* symtab,
- const Layout* layout,
+ Layout* layout,
Workqueue* workqueue,
Output_file* of)
{
+ Timer* timer = parameters->timer();
+ if (timer != NULL)
+ timer->stamp(1);
+
int thread_count = options.thread_count_final();
if (thread_count == 0)
- thread_count = input_objects->number_of_input_objects();
+ thread_count = std::max(2, input_objects->number_of_input_objects());
workqueue->set_thread_count(thread_count);
+ bool any_postprocessing_sections = layout->any_postprocessing_sections();
+
// Use a blocker to wait until all the input sections have been
// written out.
- Task_token* input_sections_blocker = new Task_token();
+ Task_token* input_sections_blocker = NULL;
+ if (!any_postprocessing_sections)
+ {
+ input_sections_blocker = new Task_token(true);
+ // Write_symbols_task, Relocate_tasks.
+ input_sections_blocker->add_blocker();
+ input_sections_blocker->add_blockers(input_objects->number_of_relobjs());
+ }
// Use a blocker to block any objects which have to wait for the
// output sections to complete before they can apply relocations.
- Task_token* output_sections_blocker = new Task_token();
+ Task_token* output_sections_blocker = new Task_token(true);
+ output_sections_blocker->add_blocker();
// Use a blocker to block the final cleanup task.
- Task_token* final_blocker = new Task_token();
-
- // Queue a task for each input object to relocate the sections and
- // write out the local symbols.
- for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
- p != input_objects->relobj_end();
- ++p)
- {
- input_sections_blocker->add_blocker();
- final_blocker->add_blocker();
- workqueue->queue(new Relocate_task(options, symtab, layout, *p, of,
- input_sections_blocker,
- output_sections_blocker,
- final_blocker));
- }
+ Task_token* final_blocker = new Task_token(true);
+ // Write_symbols_task, Write_sections_task, Write_data_task,
+ // Relocate_tasks.
+ final_blocker->add_blockers(3);
+ final_blocker->add_blockers(input_objects->number_of_relobjs());
+ if (!any_postprocessing_sections)
+ final_blocker->add_blocker();
// Queue a task to write out the symbol table.
- final_blocker->add_blocker();
- workqueue->queue(new Write_symbols_task(symtab,
- input_objects->target(),
+ workqueue->queue(new Write_symbols_task(layout,
+ symtab,
+ input_objects,
layout->sympool(),
layout->dynpool(),
of,
final_blocker));
// Queue a task to write out the output sections.
- output_sections_blocker->add_blocker();
- final_blocker->add_blocker();
workqueue->queue(new Write_sections_task(layout, of, output_sections_blocker,
+ input_sections_blocker,
final_blocker));
// Queue a task to write out everything else.
- final_blocker->add_blocker();
workqueue->queue(new Write_data_task(layout, symtab, of, final_blocker));
+ // Queue a task for each input object to relocate the sections and
+ // write out the local symbols.
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ workqueue->queue(new Relocate_task(symtab, layout, *p, of,
+ input_sections_blocker,
+ output_sections_blocker,
+ final_blocker));
+
// Queue a task to write out the output sections which depend on
- // input sections.
- final_blocker->add_blocker();
- workqueue->queue(new Write_after_input_sections_task(layout, of,
- input_sections_blocker,
- final_blocker));
-
- // Queue a task to close the output file. This will be blocked by
- // FINAL_BLOCKER.
- workqueue->queue(new Task_function(new Close_task_runner(of),
- final_blocker));
+ // input sections. If there are any sections which require
+ // postprocessing, then we need to do this last, since it may resize
+ // the output file.
+ if (!any_postprocessing_sections)
+ {
+ Task* t = new Write_after_input_sections_task(layout, of,
+ input_sections_blocker,
+ final_blocker);
+ workqueue->queue(t);
+ }
+ else
+ {
+ Task_token* new_final_blocker = new Task_token(true);
+ new_final_blocker->add_blocker();
+ Task* t = new Write_after_input_sections_task(layout, of,
+ final_blocker,
+ new_final_blocker);
+ workqueue->queue(t);
+ final_blocker = new_final_blocker;
+ }
+
+ // Create tasks for tree-style build ID computation, if necessary.
+ if (strcmp(options.build_id(), "tree") == 0)
+ {
+ // Queue a task to compute the build id. This will be blocked by
+ // FINAL_BLOCKER, and will in turn schedule the task to close
+ // the output file.
+ workqueue->queue(new Task_function(new Build_id_task_runner(&options,
+ layout,
+ of),
+ final_blocker,
+ "Task_function Build_id_task_runner"));
+ }
+ else
+ {
+ // Queue a task to close the output file. This will be blocked by
+ // FINAL_BLOCKER.
+ workqueue->queue(new Task_function(new Close_task_runner(&options, layout,
+ of, NULL, 0),
+ final_blocker,
+ "Task_function Close_task_runner"));
+ }
+
}
} // End namespace gold.
projects / deliverable / binutils-gdb.git / blobdiff