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[google] Add function name to function_patch_* sections (issue9025045)
- From: harshit at google dot com (Harshit Chopra)
- To: gcc-patches at gcc dot gnu dot org, davidxl at google dot com, reply at codereview dot appspotmail dot com
- Date: Tue, 30 Apr 2013 13:34:55 -0700
- Subject: [google] Add function name to function_patch_* sections (issue9025045)
Adding function name to the function_patch_* sections when -ffunction-sections is provided. Helps in garbage collecting dead functions with the help of linker.
Tested:
Tested using 'make -k check-gcc RUNTESTFLAGS="i386.exp=patch* --target_board=unix\{-m32,,-m64\}"'.
2013-04-30 Harshit Chopra <harshit@google.com>
* gcc/config/i386/i386.c (ix86_output_function_nops_prologue_epilogue):
(ix86_elf_asm_named_section):
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index aa6ec82..7cb832b 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -11285,6 +11285,8 @@ ix86_output_function_nops_prologue_epilogue (FILE *file,
unsigned int section_flags = SECTION_RELRO;
char *section_name_comdat = NULL;
const char *decl_section_name = NULL;
+ const char *func_name = NULL;
+ char *section_name_function_sections = NULL;
size_t len;
gcc_assert (num_remaining_nops >= 0);
@@ -11336,12 +11338,24 @@ ix86_output_function_nops_prologue_epilogue (FILE *file,
{
decl_section_name =
TREE_STRING_POINTER (DECL_SECTION_NAME (current_function_decl));
- len = strlen (decl_section_name) + strlen (section_name) + 1;
+ len = strlen (decl_section_name) + strlen (section_name) + 2;
section_name_comdat = (char *) alloca (len);
sprintf (section_name_comdat, "%s.%s", section_name, decl_section_name);
section_name = section_name_comdat;
section_flags |= SECTION_LINKONCE;
}
+ else if (flag_function_sections)
+ {
+ func_name = XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0);
+ if (func_name)
+ {
+ len = strlen (func_name) + strlen (section_name) + 2;
+ section_name_function_sections = (char *) alloca (len);
+ sprintf (section_name_function_sections, "%s.%s", section_name,
+ func_name);
+ section_name = section_name_function_sections;
+ }
+ }
section = get_section (section_name, section_flags, current_function_decl);
switch_to_section (section);
/* Align the section to 8-byte boundary. */
@@ -11369,7 +11383,7 @@ ix86_elf_asm_named_section (const char *name, unsigned int flags,
tree decl)
{
const char *section_name = name;
- if (HAVE_COMDAT_GROUP && flags & SECTION_LINKONCE)
+ if (!flag_function_sections && HAVE_COMDAT_GROUP && flags & SECTION_LINKONCE)
{
const int prologue_section_name_length =
sizeof(FUNCTION_PATCH_PROLOGUE_SECTION) - 1;
--
This patch is available for review at http://codereview.appspot.com/9025045