// gold.cc -- main linker functions
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "layout.h"
#include "reloc.h"
#include "defstd.h"
+#include "plugin.h"
+#include "gc.h"
+#include "icf.h"
+#include "incremental.h"
namespace gold
{
void
gold_exit(bool status)
{
+ if (parameters != NULL
+ && parameters->options_valid()
+ && parameters->options().has_plugins())
+ parameters->options().plugins()->cleanup();
if (!status && parameters != NULL && parameters->options_valid())
unlink_if_ordinary(parameters->options().output_file_name());
exit(status ? EXIT_SUCCESS : EXIT_FAILURE);
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
+Gc_runner::run(Workqueue* workqueue, const Task* task)
+{
+ 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
Symbol_table* symtab, Layout* layout, Mapfile* mapfile)
{
if (cmdline.begin() == cmdline.end())
- gold_fatal(_("no input files"));
+ {
+ if (options.printed_version())
+ gold_exit(true);
+ 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);
+ if (parameters->incremental())
+ {
+ Incremental_checker incremental_checker(
+ parameters->options().output_file_name(),
+ layout->incremental_inputs());
+ if (incremental_checker.can_incrementally_link_output_file())
+ {
+ // TODO: remove when incremental linking implemented.
+ printf("Incremental linking might be possible "
+ "(not implemented yet)\n");
+ }
+ // TODO: If we decide on an incremental build, fewer tasks
+ // should be scheduled.
+ }
+
// 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
{
Task_token* next_blocker = new Task_token(true);
next_blocker->add_blocker();
- workqueue->queue(new Read_symbols(options, input_objects, symtab, layout,
- &search_path, mapfile, &*p, NULL,
- this_blocker, next_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;
}
- workqueue->queue(new Task_function(new Middle_runner(options,
+ 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 (parameters->options().relocatable()
+ && (parameters->options().gc_sections()
+ || parameters->options().icf_enabled()))
+ gold_error(_("cannot mix -r with --gc-sections or --icf"));
+
+ if (parameters->options().gc_sections()
+ || parameters->options().icf_enabled())
+ {
+ workqueue->queue(new Task_function(new Gc_runner(options,
input_objects,
- symtab,
- layout,
- mapfile),
- this_blocker,
- "Task_function Middle_runner"));
+ 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"));
+ }
+}
+
+// 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(true);
+ next_blocker->add_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,
+ mapfile),
+ this_blocker,
+ "Task_function Middle_runner"));
}
// Queue up the middle set of tasks. These are the tasks which run
Workqueue* workqueue,
Mapfile* mapfile)
{
+ // 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())
+ {
+ // Find the start symbol if any.
+ Symbol* start_sym;
+ if (parameters->options().entry())
+ start_sym = symtab->lookup(parameters->options().entry());
+ else
+ start_sym = symtab->lookup("_start");
+ if (start_sym != NULL)
+ {
+ bool is_ordinary;
+ unsigned int shndx = start_sym->shndx(&is_ordinary);
+ if (is_ordinary)
+ {
+ symtab->gc()->worklist().push(
+ Section_id(start_sym->object(), shndx));
+ }
+ }
+ // 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, Object::layout is
+ // called twice. It is called the first time when the
+ // symbols are added.
+ 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_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();
+ }
+
+ 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);
+ }
+ }
+ }
+
// 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)
- set_parameters_target(¶meters->default_target());
+ parameters_force_valid_target();
int thread_count = options.thread_count_middle();
if (thread_count == 0)
workqueue->set_thread_count(thread_count);
// Now we have seen all the input files.
- const bool doing_static_link = (!input_objects->any_dynamic()
- && !parameters->options().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_error(_("cannot mix -r with dynamic object %s"),
+ 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)
+ gold_fatal(_("cannot mix split-stack '%s' and "
+ "non-split-stack '%s' when using -r"),
+ (*input_objects->relobj_begin())->name().c_str(),
+ (*p)->name().c_str());
+ }
+ }
+ }
+
if (is_debugging_enabled(DEBUG_SCRIPT))
layout->script_options()->print(stderr);
// TODO: if this is too slow, do this as a task, rather than inline.
symtab->detect_odr_violations(task, options.output_file_name());
+ // 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 symbols from any linker scripts.
layout->define_script_symbols(symtab);
- // Add any symbols named with -u options to the symbol table.
- symtab->add_undefined_symbols_from_command_line();
-
// Attach sections to segments.
layout->attach_sections_to_segments();
// Make sure we have symbols for any required group signatures.
layout->define_group_signatures(symtab);
- // 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(true);
- Task_token* symtab_lock = new Task_token(false);
- for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
- p != input_objects->relobj_end();
- ++p)
- {
- // 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));
- }
+ Task_token* this_blocker = NULL;
- // Allocate common symbols. This requires write access to the
- // symbol table, but is independent of the relocation processing.
+ // 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())
{
- blocker->add_blocker();
+ this_blocker = new Task_token(true);
+ this_blocker->add_blocker();
workqueue->queue(new Allocate_commons_task(symtab, layout, mapfile,
- symtab_lock, blocker));
+ 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
+ {
+ // 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;
+ }
+ }
+
+ 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(false);
+ }
}
// When all those tasks are complete, we can start laying out the
target,
layout,
mapfile),
- blocker,
+ this_blocker,
"Task_function Layout_task_runner"));
}
// written out.
Task_token* input_sections_blocker = NULL;
if (!any_postprocessing_sections)
- input_sections_blocker = new Task_token(true);
+ {
+ input_sections_blocker = new Task_token(true);
+ 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(true);
+ output_sections_blocker->add_blocker();
// Use a blocker to block the final cleanup task.
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(layout,
symtab,
input_objects,
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,
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
for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
p != input_objects->relobj_end();
++p)
- {
- if (input_sections_blocker != NULL)
- 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));
- }
+ 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. If there are any sections which require
// the output file.
if (!any_postprocessing_sections)
{
- final_blocker->add_blocker();
Task* t = new Write_after_input_sections_task(layout, of,
input_sections_blocker,
final_blocker);
}
else
{
- Task_token *new_final_blocker = new Task_token(true);
+ 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,
projects / thirdparty / binutils-gdb.git / blobdiff