Re: __attribute__((__unused__)) problem

[Akim Demaille]

Le 8 avr. 2013 à 10:28, Akim Demaille <address@hidden> a écrit :

> Hi Victor,
> 
> You are right, this is a serious issue :(  I will prepare a 2.7.1
> asap.  Could you please help me making sure it works properly with
> Microsoft compilers?  Actually, it would be nice if you could also
> help me kill some compiler warnings.   Please, have a look at the
> following message.
> 
> http://lists.gnu.org/archive/html/bug-bison/2013-03/msg00003.html

I will install this is {maint}.  Could you please confirm
that the following tarball addresses your issue?  Thanks in
advance!

http://www.lrde.epita.fr/~akim/download/bison-2.7.7-a565f.tar.gz

commit 80a2826e69b201f9a64c3f18825afe879472efb4
Author: Akim Demaille <address@hidden>
Date:   Mon Apr 8 10:39:48 2013 +0200

    yacc.c: do not use __attribute__ unprotected
    
    Reported by Victor Khomenko.
    http://lists.gnu.org/archive/html/bug-bison/2013-04/msg00001.html
    
    * data/glr.c (YYUSE, __attribute__): Fuse their definition into...
    * data/c.m4 (b4_attribute_define): this new macro.
    * data/yacc.c, data/glr.c: Use it.

diff --git a/NEWS b/NEWS
index 8da9cf9..b499cc1 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,11 @@ GNU Bison NEWS
 
 * Noteworthy changes in release ?.? (????-??-??) [?]
 
+** Bug fixes
+
+*** Fix compiler attribute portability (yacc.c)
+
+  With locations enabled, __attribute__ was used unprotected.
 
 * Noteworthy changes in release 2.7 (2012-12-12) [stable]
 
diff --git a/THANKS b/THANKS
index ed978d3..9b24974 100644
--- a/THANKS
+++ b/THANKS
@@ -121,6 +121,7 @@ Tom Tromey                address@hidden
 Tommy Nordgren            address@hidden
 Troy A. Johnson           address@hidden
 Tys Lefering              address@hidden
+Victor Khomenko           address@hidden
 Vin Shelton               address@hidden
 W.C.A. Wijngaards         address@hidden
 Wayne Green               address@hidden
diff --git a/data/c.m4 b/data/c.m4
index dc3d303..a1dc2c5 100644
--- a/data/c.m4
+++ b/data/c.m4
@@ -187,9 +187,29 @@ m4_define([b4_table_value_equals],
        [(!!(($2) == ($3)))])])
 
 
-## ---------##
-## Values.  ##
-## ---------##
+## ----------------- ##
+## Compiler issues.  ##
+## ----------------- ##
+
+# b4_attribute_define
+# -------------------
+# Provide portability for __attribute__.
+m4_define([b4_attribute_define],
+[#ifndef __attribute__
+/* This feature is available in gcc versions 2.5 and later.  */
+# if (! defined __GNUC__ || __GNUC__ < 2 \
+      || (__GNUC__ == 2 && __GNUC_MINOR__ < 5))
+#  define __attribute__(Spec) /* empty */
+# endif
+#endif
+
+/* Suppress unused-variable warnings by "using" E.  */
+#if ! defined lint || defined __GNUC__
+# define YYUSE(E) ((void) (E))
+#else
+# define YYUSE(E) /* empty */
+#endif
+])
 
 
 # b4_null_define
@@ -405,7 +425,7 @@ m4_define([b4_c_arg],
 ## ----------- ##
 
 # b4_sync_start(LINE, FILE)
-# -----------------------
+# -------------------------
 m4_define([b4_sync_start], [[#]line $1 $2])
 
 
diff --git a/data/glr.c b/data/glr.c
index 02a76c2..958b040 100644
--- a/data/glr.c
+++ b/data/glr.c
@@ -246,13 +246,6 @@ b4_percent_code_get[]dnl
 # endif
 #endif
 
-/* Suppress unused-variable warnings by "using" E.  */
-#if ! defined lint || defined __GNUC__
-# define YYUSE(E) ((void) (E))
-#else
-# define YYUSE(E) /* empty */
-#endif
-
 /* Identity function, used to suppress warnings about constant conditions.  */
 #ifndef lint
 # define YYID(N) (N)
@@ -291,17 +284,7 @@ b4_percent_code_get[]dnl
 # define YYLONGJMP(Env, Val) (longjmp (Env, Val), YYASSERT (0))
 #endif
 
-/*-----------------.
-| GCC extensions.  |
-`-----------------*/
-
-#ifndef __attribute__
-/* This feature is available in gcc versions 2.5 and later.  */
-# if (! defined __GNUC__ || __GNUC__ < 2 \
-      || (__GNUC__ == 2 && __GNUC_MINOR__ < 5))
-#  define __attribute__(Spec) /* empty */
-# endif
-#endif
+]b4_attribute_define[
 
 #ifndef YYASSERT
 # define YYASSERT(Condition) ((void) ((Condition) || (abort (), 0)))
diff --git a/data/yacc.c b/data/yacc.c
index b34549f..abc949b 100644
--- a/data/yacc.c
+++ b/data/yacc.c
@@ -447,12 +447,7 @@ typedef short int yytype_int16;
 # endif
 #endif
 
-/* Suppress unused-variable warnings by "using" E.  */
-#if ! defined lint || defined __GNUC__
-# define YYUSE(E) ((void) (E))
-#else
-# define YYUSE(E) /* empty */
-#endif
+]b4_attribute_define[
 
 /* Identity function, used to suppress warnings about constant conditions.  */
 #ifndef lint