Fix buglet in last patch.
[deliverable/binutils-gdb.git] / gold / layout.cc
index f7c1e40be3989946d90b48e825b881a7230bd45e..231e2c9f4146875b2516a589608ac940ab08e0bc 100644 (file)
@@ -32,6 +32,7 @@
 #include "symtab.h"
 #include "dynobj.h"
 #include "ehframe.h"
+#include "compressed_output.h"
 #include "layout.h"
 
 namespace gold
@@ -43,10 +44,11 @@ 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.
@@ -70,7 +72,9 @@ 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.
@@ -265,7 +269,7 @@ 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.
@@ -386,6 +390,22 @@ Layout::section_flags_to_segment(elfcpp::Elf_Xword flags)
   return ret;
 }
 
+// Sometimes we compress sections.  This is typically done for
+// sections that are not part of normal program execution (such as
+// .debug_* sections), and where the readers of these sections know
+// how to deal with compressed sections.  (To make it easier for them,
+// we will rename the ouput section in such cases from .foo to
+// .foo.zlib.nnnn, where nnnn is the uncompressed size.)  This routine
+// doesn't say for certain whether we'll compress -- it depends on
+// commandline options as well -- just whether this section is a
+// candidate for compression.
+
+static bool
+is_compressible_debug_section(const char* secname)
+{
+  return (strncmp(secname, ".debug", sizeof(".debug") - 1) == 0);
+}
+
 // Make a new Output_section, and attach it to segments as
 // appropriate.
 
@@ -393,7 +413,14 @@ Output_section*
 Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
                            elfcpp::Elf_Xword flags)
 {
-  Output_section* os = new Output_section(this->options_, name, type, flags);
+  Output_section* os;
+  if ((flags & elfcpp::SHF_ALLOC) == 0
+      && this->options_.compress_debug_sections()
+      && is_compressible_debug_section(name))
+    os = new Output_compressed_section(&this->options_, name, type, flags);
+  else
+    os = new Output_section(name, type, flags);
+
   this->section_list_.push_back(os);
 
   if ((flags & elfcpp::SHF_ALLOC) == 0)
@@ -628,12 +655,15 @@ 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(task, input_objects);
+
   this->create_gold_note();
   this->create_executable_stack_info(target);
 
@@ -653,7 +683,7 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab)
       std::vector<Symbol*> dynamic_symbols;
       unsigned int local_dynamic_count;
       Versions versions;
-      this->create_dynamic_symtab(target, symtab, &dynstr,
+      this->create_dynamic_symtab(input_objects, target, symtab, &dynstr,
                                  &local_dynamic_count, &dynamic_symbols,
                                  &versions);
 
@@ -703,7 +733,9 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab)
   off_t off = this->set_segment_offsets(target, load_seg, &shndx);
 
   // Create the symbol table sections.
-  this->create_symtab_sections(input_objects, symtab, &off);
+  this->create_symtab_sections(input_objects, symtab, task, &off);
+  if (!parameters->doing_static_link())
+    this->assign_local_dynsym_offsets(input_objects);
 
   // Create the .shstrtab section.
   Output_section* shstrtab_section = this->create_shstrtab();
@@ -718,6 +750,12 @@ 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
@@ -964,7 +1002,9 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
   // Find the PT_LOAD segments, and set their addresses and offsets
   // and their section's addresses and offsets.
   uint64_t addr;
-  if (options_.user_set_text_segment_address())
+  if (parameters->output_is_shared())
+    addr = 0;
+  else if (options_.user_set_text_segment_address())
     addr = options_.text_segment_address();
   else
     addr = target->default_text_segment_address();
@@ -1052,6 +1092,10 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
        (*p)->set_offset();
     }
 
+  // Set the TLS offsets for each section in the PT_TLS segment.
+  if (this->tls_segment_ != NULL)
+    this->tls_segment_->set_tls_offsets();
+
   return off;
 }
 
@@ -1069,14 +1113,21 @@ Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
       if (*p == this->symtab_section_)
        continue;
 
+      if (pass == BEFORE_INPUT_SECTIONS_PASS
+         && (*p)->requires_postprocessing())
+       {
+         (*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;
@@ -1085,23 +1136,14 @@ Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
       (*p)->set_file_offset(off);
       (*p)->finalize_data_size();
       off += (*p)->data_size();
+
+      // At this point the name must be set.
+      if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
+       this->namepool_.add((*p)->name(), false, NULL);
     }
   return off;
 }
 
-// Allow any section not associated with a segment to change its
-// output section name at the last minute.
-
-void
-Layout::modify_section_names()
-{
-  for (Section_list::iterator p = this->unattached_section_list_.begin();
-       p != this->unattached_section_list_.end();
-       ++p)
-    if ((*p)->maybe_modify_output_section_name())
-      this->namepool_.add((*p)->name(), true, NULL);
-}
-
 // Set the section indexes of all the sections not associated with a
 // segment.
 
@@ -1118,6 +1160,41 @@ Layout::set_section_indexes(unsigned int shndx)
   return shndx;
 }
 
+// Count the local symbols in the regular symbol table and the dynamic
+// symbol table, and build the respective string pools.
+
+void
+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(task, *p);
+      (*p)->count_local_symbols(&this->sympool_, &this->dynpool_);
+    }
+}
+
 // Create the symbol table sections.  Here we also set the final
 // values of the symbols.  At this point all the loadable sections are
 // fully laid out.
@@ -1125,6 +1202,7 @@ Layout::set_section_indexes(unsigned int shndx)
 void
 Layout::create_symtab_sections(const Input_objects* input_objects,
                               Symbol_table* symtab,
+                              const Task* task,
                               off_t* poff)
 {
   int symsize;
@@ -1170,10 +1248,8 @@ Layout::create_symtab_sections(const Input_objects* input_objects,
        p != input_objects->relobj_end();
        ++p)
     {
-      Task_lock_obj<Object> tlo(**p);
       unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
-                                                       off,
-                                                       &this->sympool_);
+                                                        off);
       off += (index - local_symbol_index) * symsize;
       local_symbol_index = index;
     }
@@ -1200,7 +1276,7 @@ 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,
+  off = symtab->finalize(task, local_symcount, off, dynoff, dyn_global_index,
                         dyncount, &this->sympool_);
 
   if (!parameters->strip_all())
@@ -1281,7 +1357,8 @@ Layout::create_shdrs(off_t* poff)
 // Create the dynamic symbol table.
 
 void
-Layout::create_dynamic_symtab(const Target* target, Symbol_table* symtab,
+Layout::create_dynamic_symtab(const Input_objects* input_objects,
+                              const Target* target, Symbol_table* symtab,
                              Output_section **pdynstr,
                              unsigned int* plocal_dynamic_count,
                              std::vector<Symbol*>* pdynamic_symbols,
@@ -1307,10 +1384,15 @@ Layout::create_dynamic_symtab(const Target* target, Symbol_table* symtab,
        }
     }
 
-  // FIXME: Some targets apparently require local symbols in the
-  // dynamic symbol table.  Here is where we will have to count them,
-  // and set the dynamic symbol indexes, and add the names to
-  // this->dynpool_.
+  // Count the local symbols that need to go in the dynamic symbol table,
+  // and set the dynamic symbol indexes.
+  for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+       p != input_objects->relobj_end();
+       ++p)
+    {
+      unsigned int new_index = (*p)->set_local_dynsym_indexes(index);
+      index = new_index;
+    }
 
   unsigned int local_symcount = index;
   *plocal_dynamic_count = local_symcount;
@@ -1400,6 +1482,28 @@ Layout::create_dynamic_symtab(const Target* target, Symbol_table* symtab,
   odyn->add_section_address(elfcpp::DT_HASH, hashsec);
 }
 
+// Assign offsets to each local portion of the dynamic symbol table.
+
+void
+Layout::assign_local_dynsym_offsets(const Input_objects* input_objects)
+{
+  Output_section* dynsym = this->dynsym_section_;
+  gold_assert(dynsym != NULL);
+
+  off_t off = dynsym->offset();
+
+  // Skip the dummy symbol at the start of the section.
+  off += dynsym->entsize();
+
+  for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+       p != input_objects->relobj_end();
+       ++p)
+    {
+      unsigned int count = (*p)->set_local_dynsym_offset(off);
+      off += count * dynsym->entsize();
+    }
+}
+
 // Create the version sections.
 
 void
@@ -1658,7 +1762,13 @@ Layout::finish_dynamic_section(const Input_objects* input_objects,
   // post-link tools can easily modify these flags if desired.
   unsigned int flags = 0;
   if (have_textrel)
-    flags |= elfcpp::DF_TEXTREL;
+    {
+      // Add a DT_TEXTREL for compatibility with older loaders.
+      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);
 }
 
@@ -1908,20 +2018,21 @@ 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);
-
-  // Determine the final section names as well (at least, for sections
-  // that we haven't written yet).
-  this->modify_section_names();
-
-  // 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();
@@ -1932,51 +2043,42 @@ 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);
 }
 
+// Print statistical information to stderr.  This is used for --stats.
+
+void
+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.
@@ -1991,18 +2093,18 @@ 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.
@@ -2017,18 +2119,18 @@ 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.
@@ -2044,20 +2146,20 @@ 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.
@@ -2073,7 +2175,7 @@ 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();
 }
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