Default text reordering fix with a flag to turn it off.

2013-01-24  Sriraman Tallam  <tmsriram@google.com>

	* layout.cc (Layout::layout): Check for option text_reorder.
	(Layout::make_output_section): Ditto.
	* options.h (text_reorder): New option.
	* output.cc (Input_section_sort_compare): Remove special ordering
	of section names.
	(Output_section::
	 Input_section_sort_section_name_special_ordering_compare::
	 operator()): New function.
	(Output_section::sort_attached_input_sections): Use new sort function
	for .text.
	* output.h (Input_section_sort_section_name_special_ordering_compare):
	New struct.
	* testsuite/Makefile.am (text_section_grouping): Test option
	--no-text-reorder
	* testsuite/Makefile.in: Regenerate.
	* testsuite/text_section_grouping.sh: Check order of functions without
	default text reordering.

1 files changed, 39 insertions, 13 deletions

diff --git a/gold/output.cc b/gold/output.cc
index 01126a3..22c0bf0 100644
--- a/gold/output.cc
+++ b/gold/output.cc
@@ -3389,19 +3389,6 @@ Output_section::Input_section_sort_compare::operator()(
       return s1.index() < s2.index();
     }
 
-  // Some input section names have special ordering requirements.
-  int o1 = Layout::special_ordering_of_input_section(s1.section_name().c_str());
-  int o2 = Layout::special_ordering_of_input_section(s2.section_name().c_str());
-  if (o1 != o2)
-    {
-      if (o1 < 0)
-	return false;
-      else if (o2 < 0)
-	return true;
-      else
-	return o1 < o2;
-    }
-
   // A section with a priority follows a section without a priority.
   bool s1_has_priority = s1.has_priority();
   bool s2_has_priority = s2.has_priority();
@@ -3508,6 +3495,42 @@ Output_section::Input_section_sort_section_order_index_compare::operator()(
   return s1_secn_index < s2_secn_index;
 }
 
+// Return true if S1 should come before S2.  This is the sort comparison
+// function for .text to sort sections with prefixes
+// .text.{unlikely,exit,startup,hot} before other sections.
+bool
+Output_section::Input_section_sort_section_name_special_ordering_compare
+  ::operator()(
+    const Output_section::Input_section_sort_entry& s1,
+    const Output_section::Input_section_sort_entry& s2) const
+{
+  // We sort all the sections with no names to the end.
+  if (!s1.section_has_name() || !s2.section_has_name())
+    {
+      if (s1.section_has_name())
+	return true;
+      if (s2.section_has_name())
+	return false;
+      return s1.index() < s2.index();
+    }
+ 
+  // Some input section names have special ordering requirements.
+  int o1 = Layout::special_ordering_of_input_section(s1.section_name().c_str());
+  int o2 = Layout::special_ordering_of_input_section(s2.section_name().c_str());
+  if (o1 != o2)
+    {
+      if (o1 < 0)
+	return false;
+      else if (o2 < 0)
+	return true;
+      else
+	return o1 < o2;
+    }
+
+  // Keep input order otherwise.
+  return s1.index() < s2.index();  
+}
+
 // This updates the section order index of input sections according to the
 // the order specified in the mapping from Section id to order index.
 
@@ -3576,6 +3599,9 @@ Output_section::sort_attached_input_sections()
           || this->type() == elfcpp::SHT_FINI_ARRAY)
         std::sort(sort_list.begin(), sort_list.end(),
 	          Input_section_sort_init_fini_compare());
+      else if (strcmp(this->name(), ".text") == 0)
+        std::sort(sort_list.begin(), sort_list.end(),
+	          Input_section_sort_section_name_special_ordering_compare());
       else
         std::sort(sort_list.begin(), sort_list.end(),
 	          Input_section_sort_compare());