2011-09-29 Sriraman Tallam <tmsriram@google.com>

	* layout.h (section_order_map_): New member.
	(get_section_order_map): New member function.
	* output.cc (Output_section::add_input_section): Check for patterns
	only when --section-ordering-file is specified.
	* gold.cc (queue_middle_tasks): Delay updating order of sections till
	output_sections have been formed.
	* layout.cc (Layout_Layout): Initialize section_order_map_.
	* plugin.cc (update_section_order): Store order in order_map. Do not
	update the order.
	* testsuite/Makefile.am: Add test case for plugin_final_layout.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/plugin_section_order.c: New file.
	* testsuite/plugin_final_layout.cc: New file.
	* testsuite/plugin_final_layout.sh: New file.

1 files changed, 167 insertions, 0 deletions

diff --git a/gold/testsuite/plugin_section_order.c b/gold/testsuite/plugin_section_order.c
new file mode 100644
index 0000000..0e2079b
--- /dev/null
+++ b/gold/testsuite/plugin_section_order.c
@@ -0,0 +1,167 @@
+/* plugin_section_reorder.c -- Simple plugin to reorder function sections
+
+   Copyright 2011 Free Software Foundation, Inc.
+   Written by Sriraman Tallam <tmsriram@google.com>.
+
+   This file is part of gold.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+   MA 02110-1301, USA.  */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include "plugin-api.h"
+
+static ld_plugin_get_input_section_count get_input_section_count = NULL;
+static ld_plugin_get_input_section_type get_input_section_type = NULL;
+static ld_plugin_get_input_section_name get_input_section_name = NULL;
+static ld_plugin_get_input_section_contents get_input_section_contents = NULL;
+static ld_plugin_update_section_order update_section_order = NULL;
+static ld_plugin_allow_section_ordering allow_section_ordering = NULL;
+
+enum ld_plugin_status onload(struct ld_plugin_tv *tv);
+enum ld_plugin_status claim_file_hook(const struct ld_plugin_input_file *file,
+                                      int *claimed);
+enum ld_plugin_status all_symbols_read_hook(void);
+
+/* Plugin entry point.  */
+enum ld_plugin_status
+onload(struct ld_plugin_tv *tv)
+{
+  struct ld_plugin_tv *entry;
+  for (entry = tv; entry->tv_tag != LDPT_NULL; ++entry)
+    {
+      switch (entry->tv_tag)
+        {
+        case LDPT_REGISTER_CLAIM_FILE_HOOK:
+          assert((*entry->tv_u.tv_register_claim_file) (claim_file_hook) == LDPS_OK);
+          break;
+	case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK:
+          assert((*entry->tv_u.tv_register_all_symbols_read) (all_symbols_read_hook)
+		  == LDPS_OK);
+          break;
+        case LDPT_GET_INPUT_SECTION_COUNT:
+          get_input_section_count = *entry->tv_u.tv_get_input_section_count;
+          break;
+        case LDPT_GET_INPUT_SECTION_TYPE:
+          get_input_section_type = *entry->tv_u.tv_get_input_section_type;
+          break;
+        case LDPT_GET_INPUT_SECTION_NAME:
+          get_input_section_name = *entry->tv_u.tv_get_input_section_name;
+          break;
+        case LDPT_GET_INPUT_SECTION_CONTENTS:
+          get_input_section_contents = *entry->tv_u.tv_get_input_section_contents;
+          break;
+	case LDPT_UPDATE_SECTION_ORDER:
+	  update_section_order = *entry->tv_u.tv_update_section_order;
+	  break;
+	case LDPT_ALLOW_SECTION_ORDERING:
+	  allow_section_ordering = *entry->tv_u.tv_allow_section_ordering;
+	  break;
+        default:
+          break;
+        }
+    }
+
+  if (get_input_section_count == NULL
+      || get_input_section_type == NULL
+      || get_input_section_name == NULL
+      || get_input_section_contents == NULL
+      || update_section_order == NULL
+      || allow_section_ordering == NULL)
+    {
+      fprintf(stderr, "Some interfaces are missing\n");
+      return LDPS_ERR;
+    }
+
+  return LDPS_OK;
+}
+
+inline static int is_prefix_of(const char *prefix, const char *str)
+{
+  return strncmp(prefix, str, strlen (prefix)) == 0;
+}
+
+struct ld_plugin_section section_list[3];
+int num_entries = 0;
+
+/* This function is called by the linker for every new object it encounters.  */
+enum ld_plugin_status
+claim_file_hook(const struct ld_plugin_input_file *file, int *claimed)
+{
+  static int is_ordering_specified = 0;
+  struct ld_plugin_section section;
+  unsigned int count = 0;
+  unsigned int shndx;
+
+  *claimed = 0;
+  if (is_ordering_specified == 0)
+    {
+      /* Inform the linker to prepare for section reordering.  */
+      (*allow_section_ordering)();
+      is_ordering_specified = 1;
+    }
+
+  (*get_input_section_count)(file->handle, &count);
+
+  for (shndx = 0; shndx < count; ++shndx)
+    {
+      char *name = NULL;
+      int position = 3;
+
+      section.handle = file->handle;
+      section.shndx = shndx;
+      (*get_input_section_name)(section, &name);
+
+      /* Order is foo() followed by bar() followed by baz()  */
+      if (is_prefix_of(".text.", name))
+	{
+	  if (strstr(name, "_Z3foov") != NULL)
+	    position = 0;
+	  else if (strstr(name, "_Z3barv") != NULL)
+	    position = 1;
+	  else if (strstr(name, "_Z3bazv") != NULL)
+	    position = 2;
+	  else
+	    position = 3;
+	}
+      if (position < 3)
+	{
+	  section_list[position].handle = file->handle;
+	  section_list[position].shndx = shndx;
+	  num_entries++;
+	}
+    }
+  return LDPS_OK;
+}
+
+/* This function is called by the linker after all the symbols have been read.
+   At this stage, it is fine to tell the linker the desired function order.  */
+
+enum ld_plugin_status
+all_symbols_read_hook(void)
+{
+  if (num_entries == 3)
+    update_section_order(section_list, num_entries);
+
+  return LDPS_OK;
+}
+