On nios2-linux-gnu, the testcase gcc.dg/pr65658.c was failing with a
link error. The problem was that the nios2 back end was emitting
GP-relative addressing for an uninitialized common symbol (C tentative
declaration) that had a strong definition in a shared library. That's a
dumb thing to do -- it should be treating uninitialized common symbols
similarly to weak definitions. I've checked in the attached patch to
fix it.
-Sandra
2015-10-06 Sandra Loosemore <san...@codesourcery.com>
gcc/
* config/nios2/nios2.c (nios2_symbol_ref_in_small_data_p):
For -mgpopt=local, also exclude unintialized common symbols.
* doc/invoke.texi (Nios II Options): Document the change.
Index: gcc/config/nios2/nios2.c
===================================================================
--- gcc/config/nios2/nios2.c (revision 228499)
+++ gcc/config/nios2/nios2.c (working copy)
@@ -2099,13 +2099,17 @@ nios2_symbol_ref_in_small_data_p (rtx sy
case gpopt_local:
/* Use GP-relative addressing for small data symbols that are
- not external or weak, plus any symbols that have explicitly
- been placed in a small data section. */
+ not external or weak or uninitialized common, plus any symbols
+ that have explicitly been placed in a small data section. */
if (decl && DECL_SECTION_NAME (decl))
return nios2_small_section_name_p (DECL_SECTION_NAME (decl));
return (SYMBOL_REF_SMALL_P (sym)
&& !SYMBOL_REF_EXTERNAL_P (sym)
- && !(decl && DECL_WEAK (decl)));
+ && !(decl && DECL_WEAK (decl))
+ && !(decl && DECL_COMMON (decl)
+ && (DECL_INITIAL (decl) == NULL
+ || (!in_lto_p
+ && DECL_INITIAL (decl) == error_mark_node))));
case gpopt_global:
/* Use GP-relative addressing for small data symbols, even if
Index: gcc/doc/invoke.texi
===================================================================
--- gcc/doc/invoke.texi (revision 228499)
+++ gcc/doc/invoke.texi (working copy)
@@ -18535,13 +18535,14 @@ Do not generate GP-relative accesses.
@item local
Generate GP-relative accesses for small data objects that are not
-external or weak. Also use GP-relative addressing for objects that
+external, weak, or uninitialized common symbols.
+Also use GP-relative addressing for objects that
have been explicitly placed in a small data section via a @code{section}
attribute.
@item global
As for @samp{local}, but also generate GP-relative accesses for
-small data objects that are external or weak. If you use this option,
+small data objects that are external, weak, or common. If you use this option,
you must ensure that all parts of your program (including libraries) are
compiled with the same @option{-G} setting.
