4 files changed, 69 insertions, 9 deletions

diff --git a/m4/manywarnings.m4 b/m4/manywarnings.m4
index 2760efb3f27..f3cb23be1cd 100644
--- a/m4/manywarnings.m4
+++ b/m4/manywarnings.m4
@@ -1,4 +1,4 @@
-# manywarnings.m4 serial 4
+# manywarnings.m4 serial 5
 dnl Copyright (C) 2008-2012 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -35,14 +35,12 @@ AC_DEFUN([gl_MANYWARN_COMPLEMENT],
 # make sure your gcc understands it.
 AC_DEFUN([gl_MANYWARN_ALL_GCC],
 [
-  dnl First, check if -Wno-missing-field-initializers is needed.
-  dnl -Wmissing-field-initializers is implied by -W, but that issues
-  dnl warnings with GCC version before 4.7, for the common idiom
-  dnl of initializing types on the stack to zero, using { 0, }
+  dnl First, check for some issues that only occur when combining multiple
+  dnl gcc warning categories.
   AC_REQUIRE([AC_PROG_CC])
   if test -n "$GCC"; then
 
-    dnl First, check -W -Werror -Wno-missing-field-initializers is supported
+    dnl Check if -W -Werror -Wno-missing-field-initializers is supported
     dnl with the current $CC $CFLAGS $CPPFLAGS.
     AC_MSG_CHECKING([whether -Wno-missing-field-initializers is supported])
     AC_CACHE_VAL([gl_cv_cc_nomfi_supported], [
@@ -77,8 +75,24 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC],
       ])
       AC_MSG_RESULT([$gl_cv_cc_nomfi_needed])
     fi
+
+    dnl Next, check if -Werror -Wuninitialized is useful with the
+    dnl user's choice of $CFLAGS; some versions of gcc warn that it
+    dnl has no effect if -O is not also used
+    AC_MSG_CHECKING([whether -Wuninitialized is supported])
+    AC_CACHE_VAL([gl_cv_cc_uninitialized_supported], [
+      gl_save_CFLAGS="$CFLAGS"
+      CFLAGS="$CFLAGS -Werror -Wuninitialized"
+      AC_COMPILE_IFELSE(
+        [AC_LANG_PROGRAM([[]], [[]])],
+        [gl_cv_cc_uninitialized_supported=yes],
+        [gl_cv_cc_uninitialized_supported=no])
+      CFLAGS="$gl_save_CFLAGS"])
+    AC_MSG_RESULT([$gl_cv_cc_uninitialized_supported])
+
   fi
 
+  # List all gcc warning categories.
   gl_manywarn_set=
   for gl_manywarn_item in \
     -W \
@@ -197,10 +211,14 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC],
     gl_manywarn_set="$gl_manywarn_set $gl_manywarn_item"
   done
 
-  # Disable the missing-field-initializers warning if needed
+  # Disable specific options as needed.
   if test "$gl_cv_cc_nomfi_needed" = yes; then
     gl_manywarn_set="$gl_manywarn_set -Wno-missing-field-initializers"
   fi
 
+  if test "$gl_cv_cc_uninitialized_supported" = no; then
+    gl_manywarn_set="$gl_manywarn_set -Wno-uninitialized"
+  fi
+
   $1=$gl_manywarn_set
 ])
diff --git a/m4/pselect.m4 b/m4/pselect.m4
index 97bf12cd2d6..5edacd28f85 100644
--- a/m4/pselect.m4
+++ b/m4/pselect.m4
@@ -1,4 +1,4 @@
-# pselect.m4
+# pselect.m4 serial 2
 dnl Copyright (C) 2011-2012 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -23,6 +23,44 @@ AC_DEFUN([gl_FUNC_PSELECT],
                 return !p;]])],
          [gl_cv_sig_pselect=yes],
          [gl_cv_sig_pselect=no])])
+
+    dnl On FreeBSD 8.2, pselect() doesn't always reject bad fds.
+    AC_CACHE_CHECK([whether pselect detects invalid fds],
+      [gl_cv_func_pselect_detects_ebadf],
+      [
+        AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <sys/time.h>
+#if HAVE_SYS_SELECT_H
+# include <sys/select.h>
+#endif
+#include <unistd.h>
+#include <errno.h>
+]],[[
+  fd_set set;
+  dup2(0, 16);
+  FD_ZERO(&set);
+  FD_SET(16, &set);
+  close(16);
+  struct timespec timeout;
+  timeout.tv_sec = 0;
+  timeout.tv_nsec = 5000;
+  return pselect (17, &set, NULL, NULL, &timeout, NULL) != -1 || errno != EBADF;
+]])], [gl_cv_func_pselect_detects_ebadf=yes],
+      [gl_cv_func_pselect_detects_ebadf=no],
+          [
+           case "$host_os" in
+                    # Guess yes on glibc systems.
+            *-gnu*) gl_cv_func_pselect_detects_ebadf="guessing yes" ;;
+                    # If we don't know, assume the worst.
+            *)      gl_cv_func_pselect_detects_ebadf="guessing no" ;;
+           esac
+          ])
+      ])
+    case $gl_cv_func_pselect_detects_ebadf in
+      *yes) ;;
+      *) REPLACE_PSELECT=1 ;;
+    esac
   fi
 
   if test $ac_cv_func_pselect = no || test $gl_cv_sig_pselect = no; then
diff --git a/m4/stdlib_h.m4 b/m4/stdlib_h.m4
index ab43728ace4..9c69f2e4d15 100644
--- a/m4/stdlib_h.m4
+++ b/m4/stdlib_h.m4
@@ -102,6 +102,7 @@ AC_DEFUN([gl_STDLIB_H_DEFAULTS],
   REPLACE_MALLOC=0;          AC_SUBST([REPLACE_MALLOC])
   REPLACE_MBTOWC=0;          AC_SUBST([REPLACE_MBTOWC])
   REPLACE_MKSTEMP=0;         AC_SUBST([REPLACE_MKSTEMP])
+  REPLACE_PTSNAME=0;         AC_SUBST([REPLACE_PTSNAME])
   REPLACE_PTSNAME_R=0;       AC_SUBST([REPLACE_PTSNAME_R])
   REPLACE_PUTENV=0;          AC_SUBST([REPLACE_PUTENV])
   REPLACE_RANDOM_R=0;        AC_SUBST([REPLACE_RANDOM_R])
diff --git a/m4/sys_stat_h.m4 b/m4/sys_stat_h.m4
index 8af3353ea51..f45dee1dc4d 100644
--- a/m4/sys_stat_h.m4
+++ b/m4/sys_stat_h.m4
@@ -1,4 +1,4 @@
-# sys_stat_h.m4 serial 28   -*- Autoconf -*-
+# sys_stat_h.m4 serial 27   -*- Autoconf -*-
 dnl Copyright (C) 2006-2012 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -11,6 +11,9 @@ AC_DEFUN([gl_HEADER_SYS_STAT_H],
 [
   AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
 
+  dnl For the mkdir substitute.
+  AC_REQUIRE([AC_C_INLINE])
+
   dnl Check for broken stat macros.
   AC_REQUIRE([AC_HEADER_STAT])