Merge from gnulib.

2013-05-15 manywarnings: update for GCC 4.8.0
2013-05-15 stdio: use __REDIRECT for fwrite, fwrite_unlocked
2013-05-15 sig2str, stdio, warnings: port to clang

ChangeLog

@@ -1,3 +1,10 @@
+2013-05-16  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Merge from gnulib, incorporating:
+	2013-05-15 manywarnings: update for GCC 4.8.0
+	2013-05-15 stdio: use __REDIRECT for fwrite, fwrite_unlocked
+	2013-05-15 sig2str, stdio, warnings: port to clang
+
 2013-05-15  Stefan Monnier  <monnier@iro.umontreal.ca>
 
 	* Makefile.in (install-doc): DOC file is not version specific any more.

lib/sig2str.c

@@ -325,21 +325,25 @@ sig2str (int signum, char *signame)
   {
     int rtmin = SIGRTMIN;
     int rtmax = SIGRTMAX;
+    int base, delta;
 
     if (! (rtmin <= signum && signum <= rtmax))
       return -1;
 
     if (signum <= rtmin + (rtmax - rtmin) / 2)
       {
-        int delta = signum - rtmin;
+        strcpy (signame, "RTMIN");
-        sprintf (signame, delta ? "RTMIN+%d" : "RTMIN", delta);
+        base = rtmin;
       }
     else
       {
-        int delta = rtmax - signum;
+        strcpy (signame, "RTMAX");
-        sprintf (signame, delta ? "RTMAX-%d" : "RTMAX", delta);
+        base = rtmax;
       }
 
+    delta = signum - base;
+    if (delta != 0)
+      sprintf (signame + 5, "%+d", delta);
     return 0;
   }
 }

lib/stdio.in.h

@@ -579,13 +579,23 @@ _GL_CXXALIAS_SYS (fwrite, size_t,
    <http://sources.redhat.com/bugzilla/show_bug.cgi?id=11959>,
    which sometimes causes an unwanted diagnostic for fwrite calls.
    This affects only function declaration attributes under certain
-   versions of gcc, and is not needed for C++.  */
+   versions of gcc and clang, and is not needed for C++.  */
 #  if (0 < __USE_FORTIFY_LEVEL                                          \
        && __GLIBC__ == 2 && 4 <= __GLIBC_MINOR__ && __GLIBC_MINOR__ <= 15 \
        && 3 < __GNUC__ + (4 <= __GNUC_MINOR__)                          \
        && !defined __cplusplus)
 #   undef fwrite
-#   define fwrite(a, b, c, d) ({size_t __r = fwrite (a, b, c, d); __r; })
+#   undef fwrite_unlocked
+extern size_t __REDIRECT (rpl_fwrite,
+                          (const void *__restrict, size_t, size_t,
+                           FILE *__restrict),
+                          fwrite);
+extern size_t __REDIRECT (rpl_fwrite_unlocked,
+                          (const void *__restrict, size_t, size_t,
+                           FILE *__restrict),
+                          fwrite_unlocked);
+#   define fwrite rpl_fwrite
+#   define fwrite_unlocked rpl_fwrite_unlocked
 #  endif
 # endif
 _GL_CXXALIASWARN (fwrite);

m4/manywarnings.m4

@@ -98,6 +98,7 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC],
     -W \
     -Wabi \
     -Waddress \
+    -Waggressive-loop-optimizations \
     -Wall \
     -Warray-bounds \
     -Wattributes \
@@ -125,7 +126,6 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC],
     -Wformat-security \
     -Wformat-y2k \
     -Wformat-zero-length \
-    -Wformat=2 \
     -Wfree-nonheap-object \
     -Wignored-qualifiers \
     -Wimplicit \
@@ -143,9 +143,7 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC],
     -Wmissing-braces \
     -Wmissing-declarations \
     -Wmissing-field-initializers \
-    -Wmissing-format-attribute \
     -Wmissing-include-dirs \
-    -Wmissing-noreturn \
     -Wmissing-parameter-type \
     -Wmissing-prototypes \
     -Wmudflap \
@@ -166,6 +164,7 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC],
     -Wpointer-sign \
     -Wpointer-to-int-cast \
     -Wpragmas \
+    -Wreturn-local-addr \
     -Wreturn-type \
     -Wsequence-point \
     -Wshadow \
@@ -187,7 +186,6 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC],
     -Wtype-limits \
     -Wuninitialized \
     -Wunknown-pragmas \
-    -Wunreachable-code \
     -Wunsafe-loop-optimizations \
     -Wunused \
     -Wunused-but-set-parameter \

m4/warnings.m4

@@ -1,4 +1,4 @@
-# warnings.m4 serial 7
+# warnings.m4 serial 8
 dnl Copyright (C) 2008-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -27,7 +27,7 @@ AC_DEFUN([gl_COMPILER_OPTION_IF],
 AS_VAR_PUSHDEF([gl_Flags], [_AC_LANG_PREFIX[]FLAGS])dnl
 AC_CACHE_CHECK([whether _AC_LANG compiler handles $1], m4_defn([gl_Warn]), [
   gl_save_compiler_FLAGS="$gl_Flags"
-  gl_AS_VAR_APPEND(m4_defn([gl_Flags]), [" $1"])
+  gl_AS_VAR_APPEND(m4_defn([gl_Flags]), [" $gl_unknown_warnings_are_errors $1"])
   AC_COMPILE_IFELSE([m4_default([$4], [AC_LANG_PROGRAM([])])],
                     [AS_VAR_SET(gl_Warn, [yes])],
                     [AS_VAR_SET(gl_Warn, [no])])
@@ -38,6 +38,14 @@ AS_VAR_POPDEF([gl_Flags])dnl
 AS_VAR_POPDEF([gl_Warn])dnl
 ])
 
+# gl_UNKNOWN_WARNINGS_ARE_ERRORS
+# ------------------------------
+# Clang doesn't complain about unknown warning options unless one also
+# specifies -Wunknown-warning-option -Werror.  Detect this.
+AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS],
+[gl_COMPILER_OPTION_IF([-Werror -Wunknown-warning-option],
+   [gl_unknown_warnings_are_errors='-Wunknown-warning-option -Werror'],
+   [gl_unknown_warnings_are_errors=])])
 
 # gl_WARN_ADD(OPTION, [VARIABLE = WARN_CFLAGS],
 #             [PROGRAM = AC_LANG_PROGRAM()])
@@ -47,7 +55,8 @@ AS_VAR_POPDEF([gl_Warn])dnl
 #
 # If VARIABLE is a variable name, AC_SUBST it.
 AC_DEFUN([gl_WARN_ADD],
-[gl_COMPILER_OPTION_IF([$1],
+[AC_REQUIRE([gl_UNKNOWN_WARNINGS_ARE_ERRORS])
+gl_COMPILER_OPTION_IF([$1],
   [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_CFLAGS]], [[$2]]), [" $1"])],
   [],
   [$3])