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-rw-r--r--gold/reloc.cc147
1 files changed, 143 insertions, 4 deletions
diff --git a/gold/reloc.cc b/gold/reloc.cc
index f6bef1d..669d87b 100644
--- a/gold/reloc.cc
+++ b/gold/reloc.cc
@@ -1,6 +1,6 @@
// reloc.cc -- relocate input files for gold.
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
@@ -62,11 +62,28 @@ Read_relocs::run(Workqueue* workqueue)
{
Read_relocs_data *rd = new Read_relocs_data;
this->object_->read_relocs(rd);
+ this->object_->set_relocs_data(rd);
this->object_->release();
- workqueue->queue_next(new Scan_relocs(this->options_, this->symtab_,
- this->layout_, this->object_, rd,
- this->symtab_lock_, this->blocker_));
+ // If garbage collection is desired, we must process the relocs
+ // instead of scanning the relocs as reloc processing is necessary
+ // to determine unused sections.
+ if (parameters->options().gc_sections())
+ {
+ workqueue->queue_next(new Gc_process_relocs(this->options_,
+ this->symtab_,
+ this->layout_,
+ this->object_, rd,
+ this->symtab_lock_,
+ this->blocker_));
+ }
+ else
+ {
+ workqueue->queue_next(new Scan_relocs(this->options_, this->symtab_,
+ this->layout_, this->object_, rd,
+ this->symtab_lock_,
+ this->blocker_));
+ }
}
// Return a debugging name for the task.
@@ -77,6 +94,43 @@ Read_relocs::get_name() const
return "Read_relocs " + this->object_->name();
}
+// Gc_process_relocs methods.
+
+// These tasks process the relocations read by Read_relocs and
+// determine which sections are referenced and which are garbage.
+// This task is done only when --gc-sections is used.
+
+Task_token*
+Gc_process_relocs::is_runnable()
+{
+ if (this->object_->is_locked())
+ return this->object_->token();
+ return NULL;
+}
+
+void
+Gc_process_relocs::locks(Task_locker* tl)
+{
+ tl->add(this, this->object_->token());
+ tl->add(this, this->blocker_);
+}
+
+void
+Gc_process_relocs::run(Workqueue*)
+{
+ this->object_->gc_process_relocs(this->options_, this->symtab_, this->layout_,
+ this->rd_);
+ this->object_->release();
+}
+
+// Return a debugging name for the task.
+
+std::string
+Gc_process_relocs::get_name() const
+{
+ return "Gc_process_relocs " + this->object_->name();
+}
+
// Scan_relocs methods.
// These tasks scan the relocations read by Read_relocs and mark up
@@ -296,6 +350,47 @@ Sized_relobj<size, big_endian>::do_read_relocs(Read_relocs_data* rd)
}
}
+// Process the relocs to generate mappings from source sections to referenced
+// sections. This is used during garbage colletion to determine garbage
+// sections.
+
+template<int size, bool big_endian>
+void
+Sized_relobj<size, big_endian>::do_gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Read_relocs_data* rd)
+{
+ Sized_target<size, big_endian>* target = this->sized_target();
+
+ const unsigned char* local_symbols;
+ if (rd->local_symbols == NULL)
+ local_symbols = NULL;
+ else
+ local_symbols = rd->local_symbols->data();
+
+ for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
+ p != rd->relocs.end();
+ ++p)
+ {
+ if (!parameters->options().relocatable())
+ {
+ // As noted above, when not generating an object file, we
+ // only scan allocated sections. We may see a non-allocated
+ // section here if we are emitting relocs.
+ if (p->is_data_section_allocated)
+ target->gc_process_relocs(options, symtab, layout, this,
+ p->data_shndx, p->sh_type,
+ p->contents->data(), p->reloc_count,
+ p->output_section,
+ p->needs_special_offset_handling,
+ this->local_symbol_count_,
+ local_symbols);
+ }
+ }
+}
+
+
// Scan the relocs and adjust the symbol table. This looks for
// relocations which require GOT/PLT/COPY relocations.
@@ -318,6 +413,14 @@ Sized_relobj<size, big_endian>::do_scan_relocs(const General_options& options,
p != rd->relocs.end();
++p)
{
+ // When garbage collection is on, unreferenced sections are not included
+ // in the link that would have been included normally. This is known only
+ // after Read_relocs hence this check has to be done again.
+ if (parameters->options().gc_sections())
+ {
+ if (p->output_section == NULL)
+ continue;
+ }
if (!parameters->options().relocatable())
{
// As noted above, when not generating an object file, we
@@ -1080,6 +1183,42 @@ Sized_relobj<64, true>::do_read_relocs(Read_relocs_data* rd);
#ifdef HAVE_TARGET_32_LITTLE
template
void
+Sized_relobj<32, false>::do_gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Read_relocs_data* rd);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+void
+Sized_relobj<32, true>::do_gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Read_relocs_data* rd);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+void
+Sized_relobj<64, false>::do_gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Read_relocs_data* rd);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+void
+Sized_relobj<64, true>::do_gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Read_relocs_data* rd);
+#endif
+
+#ifdef HAVE_TARGET_32_LITTLE
+template
+void
Sized_relobj<32, false>::do_scan_relocs(const General_options& options,
Symbol_table* symtab,
Layout* layout,