Re: [Patch] Potential fix for PR55033

[Alan Modra <amodra@gmail.com>]

On Tue, Oct 23, 2012 at 06:25:43PM +0200, Sebastian Huber wrote:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55033
> 
> This patch fixes my problem, but I am absolutely not sure if this is the
> right way.
[snip]

This is http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9571 all over again.

IMHO your patch is not wrong, but a better idea is that if we've used
categorize_decl_for_section to choose a section name, then we ought to
also use categorize_decl_for_section to choose section flags.

My original fix for pr9571 was to pass the decl down to
get_named_section.
http://gcc.gnu.org/ml/gcc-patches/2004-11/msg02487.html
That hit the assert in get_named_section when building libgfortran for
ia64, and my knee-jerk patch to fix that was to simply satisfy the
assert.  After looking at all the target section_type_flags functions,
I believe the following is what I should have done way back then.
Bootstrapped and regression tested powerpc64-linux.

	* varasm.c (default_elf_select_section): Move !DECL_P check..
	(get_named_section): ..to here before calling get_section_name.
	Adjust assertion.
	(default_section_type_flags): Add DECL_P check.
	* config/i386/winnt.c (i386_pe_section_type_flags): Likewise.
	* config/rs6000/rs6000.c (rs6000_xcoff_section_type_flags): Likewise.

Index: gcc/varasm.c
===================================================================
--- gcc/varasm.c	(revision 192660)
+++ gcc/varasm.c	(working copy)
@@ -403,12 +403,16 @@ get_named_section (tree decl, const char *name, in
 {
   unsigned int flags;
 
-  gcc_assert (!decl || DECL_P (decl));
   if (name == NULL)
-    name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
+    {
+      gcc_assert (decl && DECL_P (decl) && DECL_SECTION_NAME (decl));
+      name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
+    }
 
   flags = targetm.section_type_flags (decl, name, reloc);
 
+  if (decl && !DECL_P (decl))
+    decl = NULL_TREE;
   return get_section (name, flags, decl);
 }
 
@@ -5943,7 +5947,7 @@ default_section_type_flags (tree decl, const char
 	flags |= SECTION_RELRO;
     }
 
-  if (decl && DECL_ONE_ONLY (decl))
+  if (decl && DECL_P (decl) && DECL_ONE_ONLY (decl))
     flags |= SECTION_LINKONCE;
 
   if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
@@ -6299,8 +6303,6 @@ default_elf_select_section (tree decl, int reloc,
       gcc_unreachable ();
     }
 
-  if (!DECL_P (decl))
-    decl = NULL_TREE;
   return get_named_section (decl, sname, reloc);
 }
 
Index: gcc/config/i386/winnt.c
===================================================================
--- gcc/config/i386/winnt.c	(revision 192660)
+++ gcc/config/i386/winnt.c	(working copy)
@@ -476,7 +476,7 @@ i386_pe_section_type_flags (tree decl, const char
 	flags |= SECTION_PE_SHARED;
     }
 
-  if (decl && DECL_ONE_ONLY (decl))
+  if (decl && DECL_P (decl) && DECL_ONE_ONLY (decl))
     flags |= SECTION_LINKONCE;
 
   /* See if we already have an entry for this section.  */
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c	(revision 192660)
+++ gcc/config/rs6000/rs6000.c	(working copy)
@@ -25689,7 +25689,7 @@ rs6000_xcoff_section_type_flags (tree decl, const
   unsigned int flags = default_section_type_flags (decl, name, reloc);
 
   /* Align to at least UNIT size.  */
-  if (flags & SECTION_CODE || !decl)
+  if ((flags & SECTION_CODE) != 0 || !decl || !DECL_P (decl))
     align = MIN_UNITS_PER_WORD;
   else
     /* Increase alignment of large objects if not already stricter.  */

-- 
Alan Modra
Australia Development Lab, IBM