Originally from Craig Silverstein, with changes: support using a
[external/binutils.git] / gold / layout.cc
index 0a08f71..38bdcd9 100644 (file)
@@ -1,6 +1,6 @@
 // layout.cc -- lay out output file sections for gold
 
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
 // Written by Ian Lance Taylor <iant@google.com>.
 
 // This file is part of gold.
@@ -28,6 +28,7 @@
 #include <utility>
 
 #include "parameters.h"
+#include "options.h"
 #include "output.h"
 #include "symtab.h"
 #include "dynobj.h"
@@ -44,15 +45,15 @@ namespace gold
 // have been read.
 
 void
-Layout_task_runner::run(Workqueue* workqueue)
+Layout_task_runner::run(Workqueue* workqueue, const Task* task)
 {
   off_t file_size = this->layout_->finalize(this->input_objects_,
-                                           this->symtab_);
+                                           this->symtab_,
+                                           task);
 
   // Now we know the final size of the output file and we know where
   // each piece of information goes.
-  Output_file* of = new Output_file(this->options_,
-                                    this->input_objects_->target());
+  Output_file* of = new Output_file(parameters->output_file_name());
   of->open(file_size);
 
   // Queue up the final set of tasks.
@@ -62,8 +63,9 @@ Layout_task_runner::run(Workqueue* workqueue)
 
 // Layout methods.
 
-Layout::Layout(const General_options& options)
-  : options_(options), namepool_(), sympool_(), dynpool_(), signatures_(),
+Layout::Layout(const General_options& options, Script_options* script_options)
+  : options_(options), script_options_(script_options), namepool_(),
+    sympool_(), dynpool_(), signatures_(),
     section_name_map_(), segment_list_(), section_list_(),
     unattached_section_list_(), special_output_list_(),
     section_headers_(NULL), tls_segment_(NULL), symtab_section_(NULL),
@@ -71,7 +73,9 @@ Layout::Layout(const General_options& options)
     eh_frame_section_(NULL), output_file_size_(-1),
     input_requires_executable_stack_(false),
     input_with_gnu_stack_note_(false),
-    input_without_gnu_stack_note_(false)
+    input_without_gnu_stack_note_(false),
+    has_static_tls_(false),
+    any_postprocessing_sections_(false)
 {
   // Make space for more than enough segments for a typical file.
   // This is just for efficiency--it's OK if we wind up needing more.
@@ -266,7 +270,7 @@ Layout::layout(Sized_relobj<size, big_endian>* object, unsigned int shndx,
 
   // Canonicalize the section name.
   Stringpool::Key name_key;
-  name = this->namepool_.add_prefix(name, len, &name_key);
+  name = this->namepool_.add_with_length(name, len, true, &name_key);
 
   // Find the output section.  The output section is selected based on
   // the section name, type, and flags.
@@ -652,13 +656,14 @@ Layout::find_first_load_seg()
 // This function returns the size of the output file.
 
 off_t
-Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab)
+Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab,
+                const Task* task)
 {
   Target* const target = input_objects->target();
 
   target->finalize_sections(this);
 
-  this->count_local_symbols(input_objects);
+  this->count_local_symbols(task, input_objects);
 
   this->create_gold_note();
   this->create_executable_stack_info(target);
@@ -678,7 +683,7 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab)
       Output_section* dynstr;
       std::vector<Symbol*> dynamic_symbols;
       unsigned int local_dynamic_count;
-      Versions versions;
+      Versions versions(this->options_, &this->dynpool_);
       this->create_dynamic_symtab(input_objects, target, symtab, &dynstr,
                                  &local_dynamic_count, &dynamic_symbols,
                                  &versions);
@@ -716,7 +721,8 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab)
 
   // Lay out the file header.
   Output_file_header* file_header;
-  file_header = new Output_file_header(target, symtab, segment_headers);
+  file_header = new Output_file_header(target, symtab, segment_headers,
+                                      this->script_options_->entry());
   load_seg->add_initial_output_data(file_header);
   this->special_output_list_.push_back(file_header);
 
@@ -728,16 +734,26 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab)
   // they contain.
   off_t off = this->set_segment_offsets(target, load_seg, &shndx);
 
+  // Set the file offsets of all the non-data sections we've seen so
+  // far which don't have to wait for the input sections.  We need
+  // this in order to finalize local symbols in non-allocated
+  // sections.
+  off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
+
   // Create the symbol table sections.
   this->create_symtab_sections(input_objects, symtab, &off);
   if (!parameters->doing_static_link())
     this->assign_local_dynsym_offsets(input_objects);
 
+  // Process any symbol assignments from a linker script.  This must
+  // be called after the symbol table has been finalized.
+  this->script_options_->finalize_symbols(symtab, this);
+
   // Create the .shstrtab section.
   Output_section* shstrtab_section = this->create_shstrtab();
 
-  // Set the file offsets of all the non-data sections which don't
-  // have to wait for the input sections.
+  // Set the file offsets of the rest of the non-data sections which
+  // don't have to wait for the input sections.
   off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
 
   // Now that all sections have been created, set the section indexes.
@@ -746,6 +762,12 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab)
   // Create the section table header.
   this->create_shdrs(&off);
 
+  // If there are no sections which require postprocessing, we can
+  // handle the section names now, and avoid a resize later.
+  if (!this->any_postprocessing_sections_)
+    off = this->set_section_offsets(off,
+                                   STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
+
   file_header->set_section_info(this->section_headers_, shstrtab_section);
 
   // Now we know exactly where everything goes in the output file
@@ -1103,18 +1125,25 @@ Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
       if (*p == this->symtab_section_)
        continue;
 
+      // If we've already set the data size, don't set it again.
+      if ((*p)->is_offset_valid() && (*p)->is_data_size_valid())
+       continue;
+
       if (pass == BEFORE_INPUT_SECTIONS_PASS
          && (*p)->requires_postprocessing())
-       (*p)->create_postprocessing_buffer();
+       {
+         (*p)->create_postprocessing_buffer();
+         this->any_postprocessing_sections_ = true;
+       }
 
       if (pass == BEFORE_INPUT_SECTIONS_PASS
           && (*p)->after_input_sections())
         continue;
-      else if (pass == AFTER_INPUT_SECTIONS_PASS
+      else if (pass == POSTPROCESSING_SECTIONS_PASS
                && (!(*p)->after_input_sections()
                    || (*p)->type() == elfcpp::SHT_STRTAB))
         continue;
-      else if (pass == STRTAB_AFTER_INPUT_SECTIONS_PASS
+      else if (pass == STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
                && (!(*p)->after_input_sections()
                    || (*p)->type() != elfcpp::SHT_STRTAB))
         continue;
@@ -1125,7 +1154,7 @@ Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
       off += (*p)->data_size();
 
       // At this point the name must be set.
-      if (pass != STRTAB_AFTER_INPUT_SECTIONS_PASS)
+      if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
        this->namepool_.add((*p)->name(), false, NULL);
     }
   return off;
@@ -1151,13 +1180,33 @@ Layout::set_section_indexes(unsigned int shndx)
 // symbol table, and build the respective string pools.
 
 void
-Layout::count_local_symbols(const Input_objects* input_objects)
+Layout::count_local_symbols(const Task* task,
+                           const Input_objects* input_objects)
 {
+  // First, figure out an upper bound on the number of symbols we'll
+  // be inserting into each pool.  This helps us create the pools with
+  // the right size, to avoid unnecessary hashtable resizing.
+  unsigned int symbol_count = 0;
+  for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+       p != input_objects->relobj_end();
+       ++p)
+    symbol_count += (*p)->local_symbol_count();
+
+  // Go from "upper bound" to "estimate."  We overcount for two
+  // reasons: we double-count symbols that occur in more than one
+  // object file, and we count symbols that are dropped from the
+  // output.  Add it all together and assume we overcount by 100%.
+  symbol_count /= 2;
+
+  // We assume all symbols will go into both the sympool and dynpool.
+  this->sympool_.reserve(symbol_count);
+  this->dynpool_.reserve(symbol_count);
+
   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
        p != input_objects->relobj_end();
        ++p)
     {
-      Task_lock_obj<Object> tlo(**p);
+      Task_lock_obj<Object> tlo(task, *p);
       (*p)->count_local_symbols(&this->sympool_, &this->dynpool_);
     }
 }
@@ -1242,8 +1291,8 @@ Layout::create_symtab_sections(const Input_objects* input_objects,
                  == this->dynsym_section_->data_size() - locsize);
     }
 
-  off = symtab->finalize(local_symcount, off, dynoff, dyn_global_index,
-                        dyncount, &this->sympool_);
+  off = symtab->finalize(off, dynoff, dyn_global_index, dyncount,
+                        &this->sympool_, &local_symcount);
 
   if (!parameters->strip_all())
     {
@@ -1670,6 +1719,13 @@ Layout::finish_dynamic_section(const Input_objects* input_objects,
       odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname());
     }
 
+  if (parameters->output_is_shared())
+    {
+      const char* soname = this->options_.soname();
+      if (soname != NULL)
+       odyn->add_string(elfcpp::DT_SONAME, soname);
+    }
+
   // FIXME: Support --init and --fini.
   Symbol* sym = symtab->lookup("_init");
   if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
@@ -1733,6 +1789,8 @@ Layout::finish_dynamic_section(const Input_objects* input_objects,
       odyn->add_constant(elfcpp::DT_TEXTREL, 0);
       flags |= elfcpp::DF_TEXTREL;
     }
+  if (parameters->output_is_shared() && this->has_static_tls())
+    flags |= elfcpp::DF_STATIC_TLS;
   odyn->add_constant(elfcpp::DT_FLAGS, flags);
 }
 
@@ -1982,16 +2040,21 @@ Layout::write_sections_after_input_sections(Output_file* of)
   // file size.  Note we finalize the .shstrab last, to allow the
   // after_input_section sections to modify their section-names before
   // writing.
-  off_t off = this->output_file_size_;
-  off = this->set_section_offsets(off, AFTER_INPUT_SECTIONS_PASS);
-
-  // Now that we've finalized the names, we can finalize the shstrab.
-  off = this->set_section_offsets(off, STRTAB_AFTER_INPUT_SECTIONS_PASS);
-
-  if (off > this->output_file_size_)
+  if (this->any_postprocessing_sections_)
     {
-      of->resize(off);
-      this->output_file_size_ = off;
+      off_t off = this->output_file_size_;
+      off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS);
+      
+      // Now that we've finalized the names, we can finalize the shstrab.
+      off =
+       this->set_section_offsets(off,
+                                 STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
+
+      if (off > this->output_file_size_)
+       {
+         of->resize(off);
+         this->output_file_size_ = off;
+       }
     }
 
   for (Section_list::const_iterator p = this->section_list_.begin();
@@ -2002,14 +2065,6 @@ Layout::write_sections_after_input_sections(Output_file* of)
        (*p)->write(of);
     }
 
-  for (Section_list::const_iterator p = this->unattached_section_list_.begin();
-       p != this->unattached_section_list_.end();
-       ++p)
-    {
-      if ((*p)->after_input_sections())
-       (*p)->write(of);
-    }
-
   this->section_headers_->write(of);
 }
 
@@ -2021,42 +2076,31 @@ Layout::print_stats() const
   this->namepool_.print_stats("section name pool");
   this->sympool_.print_stats("output symbol name pool");
   this->dynpool_.print_stats("dynamic name pool");
+
+  for (Section_list::const_iterator p = this->section_list_.begin();
+       p != this->section_list_.end();
+       ++p)
+    (*p)->print_merge_stats();
 }
 
 // Write_sections_task methods.
 
 // We can always run this task.
 
-Task::Is_runnable_type
-Write_sections_task::is_runnable(Workqueue*)
+Task_token*
+Write_sections_task::is_runnable()
 {
-  return IS_RUNNABLE;
+  return NULL;
 }
 
 // We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
 // when finished.
 
-class Write_sections_task::Write_sections_locker : public Task_locker
-{
- public:
-  Write_sections_locker(Task_token& output_sections_blocker,
-                       Task_token& final_blocker,
-                       Workqueue* workqueue)
-    : output_sections_block_(output_sections_blocker, workqueue),
-      final_block_(final_blocker, workqueue)
-  { }
-
- private:
-  Task_block_token output_sections_block_;
-  Task_block_token final_block_;
-};
-
-Task_locker*
-Write_sections_task::locks(Workqueue* workqueue)
+void
+Write_sections_task::locks(Task_locker* tl)
 {
-  return new Write_sections_locker(*this->output_sections_blocker_,
-                                  *this->final_blocker_,
-                                  workqueue);
+  tl->add(this, this->output_sections_blocker_);
+  tl->add(this, this->final_blocker_);
 }
 
 // Run the task--write out the data.
@@ -2071,18 +2115,18 @@ Write_sections_task::run(Workqueue*)
 
 // We can always run this task.
 
-Task::Is_runnable_type
-Write_data_task::is_runnable(Workqueue*)
+Task_token*
+Write_data_task::is_runnable()
 {
-  return IS_RUNNABLE;
+  return NULL;
 }
 
 // We need to unlock FINAL_BLOCKER when finished.
 
-Task_locker*
-Write_data_task::locks(Workqueue* workqueue)
+void
+Write_data_task::locks(Task_locker* tl)
 {
-  return new Task_locker_block(*this->final_blocker_, workqueue);
+  tl->add(this, this->final_blocker_);
 }
 
 // Run the task--write out the data.
@@ -2097,18 +2141,18 @@ Write_data_task::run(Workqueue*)
 
 // We can always run this task.
 
-Task::Is_runnable_type
-Write_symbols_task::is_runnable(Workqueue*)
+Task_token*
+Write_symbols_task::is_runnable()
 {
-  return IS_RUNNABLE;
+  return NULL;
 }
 
 // We need to unlock FINAL_BLOCKER when finished.
 
-Task_locker*
-Write_symbols_task::locks(Workqueue* workqueue)
+void
+Write_symbols_task::locks(Task_locker* tl)
 {
-  return new Task_locker_block(*this->final_blocker_, workqueue);
+  tl->add(this, this->final_blocker_);
 }
 
 // Run the task--write out the symbols.
@@ -2124,20 +2168,20 @@ Write_symbols_task::run(Workqueue*)
 
 // We can only run this task after the input sections have completed.
 
-Task::Is_runnable_type
-Write_after_input_sections_task::is_runnable(Workqueue*)
+Task_token*
+Write_after_input_sections_task::is_runnable()
 {
   if (this->input_sections_blocker_->is_blocked())
-    return IS_BLOCKED;
-  return IS_RUNNABLE;
+    return this->input_sections_blocker_;
+  return NULL;
 }
 
 // We need to unlock FINAL_BLOCKER when finished.
 
-Task_locker*
-Write_after_input_sections_task::locks(Workqueue* workqueue)
+void
+Write_after_input_sections_task::locks(Task_locker* tl)
 {
-  return new Task_locker_block(*this->final_blocker_, workqueue);
+  tl->add(this, this->final_blocker_);
 }
 
 // Run the task.
@@ -2153,7 +2197,7 @@ Write_after_input_sections_task::run(Workqueue*)
 // Run the task--close the file.
 
 void
-Close_task_runner::run(Workqueue*)
+Close_task_runner::run(Workqueue*, const Task*)
 {
   this->of_->close();
 }