Update Gnulib to v0.1-77-gd9361da

[bpt/guile.git] / m4 / gettimeofday.m4

diff --git a/m4/gettimeofday.m4 b/m4/gettimeofday.m4
new file mode 100644 (file)
index 0000000..1c2d66e
--- /dev/null
+++ b/m4/gettimeofday.m4
@@ -0,0 +1,138 @@
+# serial 21
+
+# Copyright (C) 2001-2003, 2005, 2007, 2009-2014 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+dnl From Jim Meyering.
+
+AC_DEFUN([gl_FUNC_GETTIMEOFDAY],
+[
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([gl_HEADER_SYS_TIME_H])
+  AC_REQUIRE([gl_HEADER_SYS_TIME_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([gettimeofday])
+
+  gl_gettimeofday_timezone=void
+  if test $ac_cv_func_gettimeofday != yes; then
+    HAVE_GETTIMEOFDAY=0
+  else
+    gl_FUNC_GETTIMEOFDAY_CLOBBER
+    AC_CACHE_CHECK([for gettimeofday with POSIX signature],
+      [gl_cv_func_gettimeofday_posix_signature],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM(
+            [[#include <sys/time.h>
+              struct timeval c;
+              int gettimeofday (struct timeval *restrict, void *restrict);
+            ]],
+            [[/* glibc uses struct timezone * rather than the POSIX void *
+                 if _GNU_SOURCE is defined.  However, since the only portable
+                 use of gettimeofday uses NULL as the second parameter, and
+                 since the glibc definition is actually more typesafe, it is
+                 not worth wrapping this to get a compliant signature.  */
+              int (*f) (struct timeval *restrict, void *restrict)
+                = gettimeofday;
+              int x = f (&c, 0);
+              return !(x | c.tv_sec | c.tv_usec);
+            ]])],
+          [gl_cv_func_gettimeofday_posix_signature=yes],
+          [AC_COMPILE_IFELSE(
+            [AC_LANG_PROGRAM(
+              [[#include <sys/time.h>
+int gettimeofday (struct timeval *restrict, struct timezone *restrict);
+              ]])],
+            [gl_cv_func_gettimeofday_posix_signature=almost],
+            [gl_cv_func_gettimeofday_posix_signature=no])])])
+    if test $gl_cv_func_gettimeofday_posix_signature = almost; then
+      gl_gettimeofday_timezone='struct timezone'
+    elif test $gl_cv_func_gettimeofday_posix_signature != yes; then
+      REPLACE_GETTIMEOFDAY=1
+    fi
+    dnl If we override 'struct timeval', we also have to override gettimeofday.
+    if test $REPLACE_STRUCT_TIMEVAL = 1; then
+      REPLACE_GETTIMEOFDAY=1
+    fi
+    m4_ifdef([gl_FUNC_TZSET_CLOBBER], [
+      gl_FUNC_TZSET_CLOBBER
+      case "$gl_cv_func_tzset_clobber" in
+        *yes)
+          REPLACE_GETTIMEOFDAY=1
+          gl_GETTIMEOFDAY_REPLACE_LOCALTIME
+          AC_DEFINE([tzset], [rpl_tzset],
+            [Define to rpl_tzset if the wrapper function should be used.])
+          AC_DEFINE([TZSET_CLOBBERS_LOCALTIME], [1],
+            [Define if tzset clobbers localtime's static buffer.])
+          ;;
+      esac
+    ])
+  fi
+  AC_DEFINE_UNQUOTED([GETTIMEOFDAY_TIMEZONE], [$gl_gettimeofday_timezone],
+    [Define this to 'void' or 'struct timezone' to match the system's
+     declaration of the second argument to gettimeofday.])
+])
+
+
+dnl See if gettimeofday clobbers the static buffer that localtime uses
+dnl for its return value.  The gettimeofday function from Mac OS X 10.0.4
+dnl (i.e., Darwin 1.3.7) has this problem.
+dnl
+dnl If it does, then arrange to use gettimeofday and localtime only via
+dnl the wrapper functions that work around the problem.
+
+AC_DEFUN([gl_FUNC_GETTIMEOFDAY_CLOBBER],
+[
+ AC_REQUIRE([gl_HEADER_SYS_TIME_H])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+
+ AC_CACHE_CHECK([whether gettimeofday clobbers localtime buffer],
+  [gl_cv_func_gettimeofday_clobber],
+  [AC_RUN_IFELSE(
+     [AC_LANG_PROGRAM(
+        [[#include <string.h>
+          #include <sys/time.h>
+          #include <time.h>
+          #include <stdlib.h>
+        ]],
+        [[
+          time_t t = 0;
+          struct tm *lt;
+          struct tm saved_lt;
+          struct timeval tv;
+          lt = localtime (&t);
+          saved_lt = *lt;
+          gettimeofday (&tv, NULL);
+          return memcmp (lt, &saved_lt, sizeof (struct tm)) != 0;
+        ]])],
+     [gl_cv_func_gettimeofday_clobber=no],
+     [gl_cv_func_gettimeofday_clobber=yes],
+     [# When cross-compiling:
+      case "$host_os" in
+                # Guess all is fine on glibc systems.
+        *-gnu*) gl_cv_func_gettimeofday_clobber="guessing no" ;;
+                # If we don't know, assume the worst.
+        *)      gl_cv_func_gettimeofday_clobber="guessing yes" ;;
+      esac
+     ])])
+
+ case "$gl_cv_func_gettimeofday_clobber" in
+   *yes)
+     REPLACE_GETTIMEOFDAY=1
+     gl_GETTIMEOFDAY_REPLACE_LOCALTIME
+     AC_DEFINE([GETTIMEOFDAY_CLOBBERS_LOCALTIME], [1],
+       [Define if gettimeofday clobbers the localtime buffer.])
+     ;;
+ esac
+])
+
+AC_DEFUN([gl_GETTIMEOFDAY_REPLACE_LOCALTIME], [
+  REPLACE_GMTIME=1
+  REPLACE_LOCALTIME=1
+])
+
+# Prerequisites of lib/gettimeofday.c.
+AC_DEFUN([gl_PREREQ_GETTIMEOFDAY], [
+  AC_CHECK_HEADERS([sys/timeb.h])
+  AC_CHECK_FUNCS([_ftime])
+])