gcc rodata regression

[Segher Boessenkool]

On Sat, Jan 31, 2015 at 05:09:29PM -0700, Simon Glass wrote:
> I have been fighting with a strange problem on ARM where gcc puts all
> the .rodata from a number of files lumped into a single .rodata
> section even when -fdata-sections is used.
> 
> I searched and found a bug report here:
> 
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54303
> 
> which exactly describes the problem I see.

You could try this patch.  I think there were still some problems with
it, there must have been some reason I didn't submit it.  Cannot have
been just laziness :-P

Cheers,


Segher


>From 1c1ebc41fca45f497e019a5ab433c68d23010f31 Mon Sep 17 00:00:00 2001
Message-Id: <1c1ebc41fca45f497e019a5ab433c68d23010f31.1422864485.git.segher@kernel.crashing.org>
From: Segher Boessenkool <segher@kernel.crashing.org>
Date: Sat, 12 Oct 2013 15:41:50 -0700
Subject: [PATCH] Make mergeable read-only sections per-function, if requested.

---
 gcc/varasm.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/gcc/varasm.c b/gcc/varasm.c
index 295c27d..ee57a45 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -740,6 +740,16 @@ default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
   return readonly_data_section;
 }
 
+const char *
+function_mergeable_rodata_prefix (void)
+{
+  section *s = targetm.asm_out.function_rodata_section (current_function_decl);
+  if (SECTION_STYLE (s) == SECTION_NAMED)
+    return s->named.name;
+      else
+    return targetm.asm_out.mergeable_rodata_prefix;
+}
+
 /* Return the section to use for string merging.  */
 
 static section *
@@ -761,7 +771,7 @@ mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
       const char *str;
       HOST_WIDE_INT i;
       int j, unit;
-      const char *prefix = targetm.asm_out.mergeable_rodata_prefix;
+      const char *prefix = function_mergeable_rodata_prefix ();
       char *name = (char *) alloca (strlen (prefix) + 30);
 
       mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
@@ -814,7 +824,7 @@ mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
       && align <= 256
       && (align & (align - 1)) == 0)
     {
-      const char *prefix = targetm.asm_out.mergeable_rodata_prefix;
+      const char *prefix = function_mergeable_rodata_prefix ();
       char *name = (char *) alloca (strlen (prefix) + 30);
 
       sprintf (name, "%s.cst%d", prefix, (int) (align / 8));
-- 
1.8.1.4