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authorDoug Kwan <dougkwan@google.com>2009-10-24 09:36:15 +0000
committerDoug Kwan <dougkwan@google.com>2009-10-24 09:36:15 +0000
commit07f508a2532b91550e2ddafc1dd09ed05b6fa219 (patch)
tree3c5373d303af1872991c533def9157dd22e739d7 /gold
parentf09d60e19b823fd95f313d95449a933296ce6bc7 (diff)
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2009-10-24 Doug Kwan <dougkwan@google.com>
* arm.cc (Arm_output_section, Arm_relobj): Forward class declarations. (Arm_input_section::as_arm_input_section): New method. (Arm_output_section): New class definition. (Arm_output_section::create_stub_group, Arm_output_section::group_sections): New method definitions.
Diffstat (limited to 'gold')
-rw-r--r--gold/ChangeLog8
-rw-r--r--gold/arm.cc259
2 files changed, 267 insertions, 0 deletions
diff --git a/gold/ChangeLog b/gold/ChangeLog
index 60ef9d0..7799d6c 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,11 @@
+2009-10-24 Doug Kwan <dougkwan@google.com>
+
+ * arm.cc (Arm_output_section, Arm_relobj): Forward class declarations.
+ (Arm_input_section::as_arm_input_section): New method.
+ (Arm_output_section): New class definition.
+ (Arm_output_section::create_stub_group,
+ Arm_output_section::group_sections): New method definitions.
+
2009-10-22 Doug Kwan <dougkwan@google.com>
* arm.cc (Arm_input_section): New class definition.
diff --git a/gold/arm.cc b/gold/arm.cc
index b8bce33..4de6aab 100644
--- a/gold/arm.cc
+++ b/gold/arm.cc
@@ -62,6 +62,12 @@ template<bool big_endian>
class Arm_input_section;
template<bool big_endian>
+class Arm_output_section;
+
+template<bool big_endian>
+class Arm_relobj;
+
+template<bool big_endian>
class Target_arm;
// For convenience.
@@ -778,6 +784,12 @@ class Arm_input_section : public Output_relaxed_input_section
set_stub_table(Stub_table<big_endian>* stub_table)
{ this->stub_table_ = stub_table; }
+ // Downcast a base pointer to an Arm_input_section pointer. This is
+ // not type-safe but we only use Arm_input_section not the base class.
+ static Arm_input_section<big_endian>*
+ as_arm_input_section(Output_relaxed_input_section* poris)
+ { return static_cast<Arm_input_section<big_endian>*>(poris); }
+
protected:
// Write data to output file.
void
@@ -834,6 +846,44 @@ class Arm_input_section : public Output_relaxed_input_section
Stub_table<big_endian>* stub_table_;
};
+// Arm output section class. This is defined mainly to add a number of
+// stub generation methods.
+
+template<bool big_endian>
+class Arm_output_section : public Output_section
+{
+ public:
+ Arm_output_section(const char* name, elfcpp::Elf_Word type,
+ elfcpp::Elf_Xword flags)
+ : Output_section(name, type, flags)
+ { }
+
+ ~Arm_output_section()
+ { }
+
+ // Group input sections for stub generation.
+ void
+ group_sections(section_size_type, bool, Target_arm<big_endian>*);
+
+ // Downcast a base pointer to an Arm_output_section pointer. This is
+ // not type-safe but we only use Arm_output_section not the base class.
+ static Arm_output_section<big_endian>*
+ as_arm_output_section(Output_section* os)
+ { return static_cast<Arm_output_section<big_endian>*>(os); }
+
+ private:
+ // For convenience.
+ typedef Output_section::Input_section Input_section;
+ typedef Output_section::Input_section_list Input_section_list;
+
+ // Create a stub group.
+ void create_stub_group(Input_section_list::const_iterator,
+ Input_section_list::const_iterator,
+ Input_section_list::const_iterator,
+ Target_arm<big_endian>*,
+ std::vector<Output_relaxed_input_section*>*);
+};
+
// Utilities for manipulating integers of up to 32-bits
namespace utils
@@ -2649,6 +2699,215 @@ Arm_input_section<big_endian>::do_reset_address_and_file_offset()
this->set_current_data_size(off);
}
+// Arm_output_section methods.
+
+// Create a stub group for input sections from BEGIN to END. OWNER
+// points to the input section to be the owner a new stub table.
+
+template<bool big_endian>
+void
+Arm_output_section<big_endian>::create_stub_group(
+ Input_section_list::const_iterator begin,
+ Input_section_list::const_iterator end,
+ Input_section_list::const_iterator owner,
+ Target_arm<big_endian>* target,
+ std::vector<Output_relaxed_input_section*>* new_relaxed_sections)
+{
+ // Currently we convert ordinary input sections into relaxed sections only
+ // at this point but we may want to support creating relaxed input section
+ // very early. So we check here to see if owner is already a relaxed
+ // section.
+
+ Arm_input_section<big_endian>* arm_input_section;
+ if (owner->is_relaxed_input_section())
+ {
+ arm_input_section =
+ Arm_input_section<big_endian>::as_arm_input_section(
+ owner->relaxed_input_section());
+ }
+ else
+ {
+ gold_assert(owner->is_input_section());
+ // Create a new relaxed input section.
+ arm_input_section =
+ target->new_arm_input_section(owner->relobj(), owner->shndx());
+ new_relaxed_sections->push_back(arm_input_section);
+ }
+
+ // Create a stub table.
+ Stub_table<big_endian>* stub_table =
+ target->new_stub_table(arm_input_section);
+
+ arm_input_section->set_stub_table(stub_table);
+
+ Input_section_list::const_iterator p = begin;
+ Input_section_list::const_iterator prev_p;
+
+ // Look for input sections or relaxed input sections in [begin ... end].
+ do
+ {
+ if (p->is_input_section() || p->is_relaxed_input_section())
+ {
+ // The stub table information for input sections live
+ // in their objects.
+ Arm_relobj<big_endian>* arm_relobj =
+ Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
+ arm_relobj->set_stub_table(p->shndx(), stub_table);
+ }
+ prev_p = p++;
+ }
+ while (prev_p != end);
+}
+
+// Group input sections for stub generation. GROUP_SIZE is roughly the limit
+// of stub groups. We grow a stub group by adding input section until the
+// size is just below GROUP_SIZE. The last input section will be converted
+// into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
+// input section after the stub table, effectively double the group size.
+//
+// This is similar to the group_sections() function in elf32-arm.c but is
+// implemented differently.
+
+template<bool big_endian>
+void
+Arm_output_section<big_endian>::group_sections(
+ section_size_type group_size,
+ bool stubs_always_after_branch,
+ Target_arm<big_endian>* target)
+{
+ // We only care about sections containing code.
+ if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
+ return;
+
+ // States for grouping.
+ typedef enum
+ {
+ // No group is being built.
+ NO_GROUP,
+ // A group is being built but the stub table is not found yet.
+ // We keep group a stub group until the size is just under GROUP_SIZE.
+ // The last input section in the group will be used as the stub table.
+ FINDING_STUB_SECTION,
+ // A group is being built and we have already found a stub table.
+ // We enter this state to grow a stub group by adding input section
+ // after the stub table. This effectively doubles the group size.
+ HAS_STUB_SECTION
+ } State;
+
+ // Any newly created relaxed sections are stored here.
+ std::vector<Output_relaxed_input_section*> new_relaxed_sections;
+
+ State state = NO_GROUP;
+ section_size_type off = 0;
+ section_size_type group_begin_offset = 0;
+ section_size_type group_end_offset = 0;
+ section_size_type stub_table_end_offset = 0;
+ Input_section_list::const_iterator group_begin =
+ this->input_sections().end();
+ Input_section_list::const_iterator stub_table =
+ this->input_sections().end();
+ Input_section_list::const_iterator group_end = this->input_sections().end();
+ for (Input_section_list::const_iterator p = this->input_sections().begin();
+ p != this->input_sections().end();
+ ++p)
+ {
+ section_size_type section_begin_offset =
+ align_address(off, p->addralign());
+ section_size_type section_end_offset =
+ section_begin_offset + p->data_size();
+
+ // Check to see if we should group the previously seens sections.
+ switch(state)
+ {
+ case NO_GROUP:
+ break;
+
+ case FINDING_STUB_SECTION:
+ // Adding this section makes the group larger than GROUP_SIZE.
+ if (section_end_offset - group_begin_offset >= group_size)
+ {
+ if (stubs_always_after_branch)
+ {
+ gold_assert(group_end != this->input_sections().end());
+ this->create_stub_group(group_begin, group_end, group_end,
+ target, &new_relaxed_sections);
+ state = NO_GROUP;
+ }
+ else
+ {
+ // But wait, there's more! Input sections up to
+ // stub_group_size bytes after the stub table can be
+ // handled by it too.
+ state = HAS_STUB_SECTION;
+ stub_table = group_end;
+ stub_table_end_offset = group_end_offset;
+ }
+ }
+ break;
+
+ case HAS_STUB_SECTION:
+ // Adding this section makes the post stub-section group larger
+ // than GROUP_SIZE.
+ if (section_end_offset - stub_table_end_offset >= group_size)
+ {
+ gold_assert(group_end != this->input_sections().end());
+ this->create_stub_group(group_begin, group_end, stub_table,
+ target, &new_relaxed_sections);
+ state = NO_GROUP;
+ }
+ break;
+
+ default:
+ gold_unreachable();
+ }
+
+ // If we see an input section and currently there is no group, start
+ // a new one. Skip any empty sections.
+ if ((p->is_input_section() || p->is_relaxed_input_section())
+ && (p->relobj()->section_size(p->shndx()) != 0))
+ {
+ if (state == NO_GROUP)
+ {
+ state = FINDING_STUB_SECTION;
+ group_begin = p;
+ group_begin_offset = section_begin_offset;
+ }
+
+ // Keep track of the last input section seen.
+ group_end = p;
+ group_end_offset = section_end_offset;
+ }
+
+ off = section_end_offset;
+ }
+
+ // Create a stub group for any ungrouped sections.
+ if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
+ {
+ gold_assert(group_end != this->input_sections().end());
+ this->create_stub_group(group_begin, group_end,
+ (state == FINDING_STUB_SECTION
+ ? group_end
+ : stub_table),
+ target, &new_relaxed_sections);
+ }
+
+ // Convert input section into relaxed input section in a batch.
+ if (!new_relaxed_sections.empty())
+ this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
+
+ // Update the section offsets
+ for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
+ {
+ Arm_relobj<big_endian>* arm_relobj =
+ Arm_relobj<big_endian>::as_arm_relobj(
+ new_relaxed_sections[i]->relobj());
+ unsigned int shndx = new_relaxed_sections[i]->shndx();
+ // Tell Arm_relobj that this input section is converted.
+ arm_relobj->convert_input_section_to_relaxed_section(shndx);
+ }
+}
+
// A class to handle the PLT data.
template<bool big_endian>