[google][4.6]Make option -freorder-functions= invoke function reordering linker plugin

gcc/gcc.c

Index: gcc/gcc.c 
=================================================================== 
--- gcc/gcc.c	(revision 185372) 
+++ gcc/gcc.c	(working copy) 
@@ -663,6 +663,9 @@ proper position among the other output files. */ 
 -plugin-opt=-fresolution=%u.res \ 
 %{!nostdlib:%{!nodefaultlibs:%:pass-through-libs(%(link_gcc_c_sequence))}} \ 
 }"PLUGIN_COND_CLOSE" \ 
+ %{freorder-functions=*: \ 
+ -plugin %(func_reorder_linker_plugin_file) \ 
+ -plugin-opt=%(func_reorder_linker_plugin_opt)} \ 
 %{flto|flto=*:%<fcompare-debug*} \ 
 %{flto} %{flto=*} %l " LINK_PIE_SPEC \ 
 "%{fuse-ld=gold:%{fuse-ld=bfd:%e-fuse-ld=gold and -fuse-ld=bfd may not be used together}} \ 
@@ -717,6 +720,8 @@ static const char *endfile_spec = ENDFILE_SPEC; 
 static const char *startfile_spec = STARTFILE_SPEC; 
 static const char *linker_name_spec = LINKER_NAME; 
 static const char *linker_plugin_file_spec = ""; 
+static const char *func_reorder_linker_plugin_file_spec = ""; 
+static const char *func_reorder_linker_plugin_opt = ""; 
 static const char *lto_wrapper_spec = ""; 
 static const char *lto_gcc_spec = ""; 
 static const char *link_command_spec = LINK_COMMAND_SPEC; 
@@ -1206,6 +1211,10 @@ static struct spec_list static_specs[] = 
 INIT_STATIC_SPEC ("multilib_options",	&multilib_options), 
 INIT_STATIC_SPEC ("linker",	&linker_name_spec), 
 INIT_STATIC_SPEC ("linker_plugin_file",	&linker_plugin_file_spec), 
+ INIT_STATIC_SPEC ("func_reorder_linker_plugin_file", 
+ &func_reorder_linker_plugin_file_spec), 
+ INIT_STATIC_SPEC ("func_reorder_linker_plugin_opt", 
+ &func_reorder_linker_plugin_opt), 
 INIT_STATIC_SPEC ("lto_wrapper",	&lto_wrapper_spec), 
 INIT_STATIC_SPEC ("lto_gcc",	&lto_gcc_spec), 
 INIT_STATIC_SPEC ("link_libgcc",	&link_libgcc_spec), 
@@ -6108,6 +6117,51 @@ compare_files (char *cmpfile[]) 
 return ret; 
 } 
 
+/* Set func_reorder_linker_plugin_file_spec and func_reorder_linker_plugin_opt 
+ here. This is the linker plugin to do global function reordering and is 
+ enabled with -freorder-functions=*. */ 
+ 
+static void 
+set_func_reorder_linker_plugin_spec (void) 
+{ 
+ int i; 
+ const char *plugin_opt_none = "group=none"; 
+ const char *plugin_opt_callgraph = "group=callgraph"; 
+ 
+ /* Find the linker plugin that does function ordering. */ 
+ func_reorder_linker_plugin_file_spec = find_a_file (&exec_prefixes, 
+ FRPLUGINSONAME, R_OK, false); 
+ 
+ if (!func_reorder_linker_plugin_file_spec) 
+ fatal_error ("-freorder-functions=*, but " 
+ FRPLUGINSONAME " file not found"); 
+ 
+ func_reorder_linker_plugin_opt = plugin_opt_none; 
+ 
+ /* Set linker plugin options here. Option ordering is also checked here. 
+ -fno-reorder-functions or -freorder-functions should disable any 
+ previous -freorder-functions=*. */ 
+ for (i = 0; (int) i < n_switches; i++) 
+ { 
+ /* Check for match with "-freorder-functions=callgraph". */ 
+ if (func_reorder_linker_plugin_opt != plugin_opt_callgraph 
+ && !strcmp (switches[i].part1, "freorder-functions=callgraph")) 
+	{ 
+ func_reorder_linker_plugin_opt = plugin_opt_callgraph; 
+ continue; 
+	} 
+ /* Set option to none if it matches -fno-reorder-functions 
+ or -freorder-functions */ 
+ if (func_reorder_linker_plugin_opt != plugin_opt_none 
+ && (!strcmp (switches[i].part1, "fno-reorder-functions") 
+ || !strcmp (switches[i].part1, "freorder-functions"))) 
+	{ 
+ func_reorder_linker_plugin_opt = plugin_opt_none; 
+ continue; 
+	} 
+ } 
+} 
+ 
 extern int main (int, char **); 
 
 int 
@@ -6843,6 +6897,8 @@ warranty; not even for MERCHANTABILITY or FITNESS 
 const char *fuse_linker_plugin = "fuse-linker-plugin"; 
 #endif 
 
+ const char *freorder_functions_ = "freorder-functions="; 
+ 
 /* We'll use ld if we can't find collect2. */ 
 if (! strcmp (linker_name_spec, "collect2")) 
	{ 
@@ -6866,6 +6922,12 @@ warranty; not even for MERCHANTABILITY or FITNESS 
 fatal_error ("-fuse-linker-plugin, but " LTOPLUGINSONAME " not found"); 
	} 
 lto_gcc_spec = argv[0]; 
+ 
+ /* The function reordering linker plugin will be loaded if the option 
+ -freorder-functions= is present in the command-line. */ 
+ if (switch_matches (freorder_functions_, 
+ freorder_functions_ + strlen (freorder_functions_), 1)) 
+	set_func_reorder_linker_plugin_spec (); 
 
 /* Rebuild the COMPILER_PATH and LIBRARY_PATH environment variables 
 for collect. */