X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gold%2Fgold.cc;h=564ca39ebba2a1e5dc10f931690540ac9b66b9cb;hb=4fb3aee212ad7ebb51327a61db1066303084d515;hp=396a5a940f3744feb63b45e9e64ac38a4be085ad;hpb=f3e9c5c5170afd576cb1c31464472587aba05f52;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/gold.cc b/gold/gold.cc index 396a5a940f..564ca39ebb 100644 --- a/gold/gold.cc +++ b/gold/gold.cc @@ -1,6 +1,6 @@ // 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 . // This file is part of gold. @@ -40,6 +40,10 @@ #include "layout.h" #include "reloc.h" #include "defstd.h" +#include "plugin.h" +#include "gc.h" +#include "icf.h" +#include "incremental.h" namespace gold { @@ -49,6 +53,10 @@ const char* program_name; 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); @@ -60,9 +68,18 @@ gold_nomem() // 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)); + + // 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(false); } @@ -85,9 +102,9 @@ class Middle_runner : public Task_function_runner 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 @@ -98,13 +115,46 @@ class Middle_runner : public Task_function_runner 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->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. @@ -114,16 +164,35 @@ queue_initial_tasks(const General_options& options, 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 (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 @@ -135,18 +204,95 @@ queue_initial_tasks(const General_options& options, { 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_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), - 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 @@ -159,14 +305,99 @@ queue_middle_tasks(const General_options& options, const Input_objects* input_objects, Symbol_table* symtab, Layout* layout, - Workqueue* workqueue) + 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 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) @@ -174,23 +405,42 @@ queue_middle_tasks(const General_options& options, 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); @@ -202,6 +452,16 @@ queue_middle_tasks(const General_options& options, // 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(); @@ -212,9 +472,6 @@ queue_middle_tasks(const General_options& options, // 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(); @@ -231,40 +488,78 @@ queue_middle_tasks(const General_options& options, // 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) + 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()) { - // 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)); + this_blocker = new Task_token(true); + this_blocker->add_blocker(); + workqueue->queue(new Allocate_commons_task(symtab, layout, mapfile, + this_blocker)); } - // Allocate common symbols. This requires write access to the - // symbol table, but is independent of the relocation processing. - if (parameters->options().define_common()) + // 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 { - blocker->add_blocker(); - workqueue->queue(new Allocate_commons_task(symtab, layout, 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; + } + } + + 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 @@ -275,8 +570,9 @@ queue_middle_tasks(const General_options& options, input_objects, symtab, target, - layout), - blocker, + layout, + mapfile), + this_blocker, "Task_function Layout_task_runner")); } @@ -302,17 +598,26 @@ queue_final_tasks(const General_options& options, // 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, @@ -322,13 +627,10 @@ queue_final_tasks(const General_options& options, 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 @@ -336,15 +638,10 @@ queue_final_tasks(const General_options& options, 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 @@ -352,7 +649,6 @@ queue_final_tasks(const General_options& options, // 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); @@ -360,7 +656,7 @@ queue_final_tasks(const General_options& options, } 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,