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Use a more bulletproof test for whether finite() and isinf() are present.

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It seems that recent gcc versions can optimize away calls to these functions
even when the functions do not exist on the platform, resulting in a bogus
positive result.  Avoid this by using a non-constant argument and ensuring
that the function result is not simply discarded.  Per report from
François Laupretre.
This commit is contained in:
Tom Lane
2006-01-12 19:24:48 +00:00
parent b4feb29e0d
commit 158c7f32b4
2 changed files with 18 additions and 10 deletions
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10
configure vendored
View File

@@ -10382,7 +10382,6 @@ fi
# do this one the hard way in case isinf() is a macro
echo "$as_me:$LINENO: checking for isinf" >&5
echo $ECHO_N "checking for isinf... $ECHO_C" >&6
if test "${ac_cv_func_isinf+set}" = set; then
@@ -10391,7 +10390,9 @@ else
cat >conftest.$ac_ext <<_ACEOF
#line $LINENO "configure"
#include "confdefs.h"
#include <math.h>
double glob_double;
#ifdef F77_DUMMY_MAIN
# ifdef __cplusplus
@@ -10402,7 +10403,7 @@ else
int
main ()
{
double x = 0.0; int res = isinf(x);
return isinf(glob_double) ? 0 : 1;
;
return 0;
}
@@ -10913,7 +10914,10 @@ echo $ECHO_N "checking for finite... $ECHO_C" >&6
cat >conftest.$ac_ext <<_ACEOF
#line $LINENO "configure"
#include "confdefs.h"
#include <math.h>
double glob_double;
#ifdef F77_DUMMY_MAIN
# ifdef __cplusplus
extern "C"
@@ -10923,7 +10927,7 @@ cat >conftest.$ac_ext <<_ACEOF
int
main ()
{
int dummy=finite(1.0);
return finite(glob_double) ? 0 : 1;
;
return 0;
}

18
configure.in
View File

@@ -1,5 +1,5 @@
dnl Process this file with autoconf to produce a configure script.
dnl $Header: /cvsroot/pgsql/configure.in,v 1.217.2.21 2006/01/05 03:59:19 momjian Exp $
dnl $Header: /cvsroot/pgsql/configure.in,v 1.217.2.22 2006/01/12 19:24:47 tgl Exp $
dnl
dnl Developers, please strive to achieve this order:
dnl
@@ -823,12 +823,13 @@ AC_CHECK_FUNCS(vsnprintf, [], pgac_need_repl_snprintf=yes)
AC_CHECK_DECLS([snprintf, vsnprintf])
# do this one the hard way in case isinf() is a macro
dnl Cannot use AC_CHECK_FUNC because isinf may be a macro
AC_CACHE_CHECK([for isinf], ac_cv_func_isinf,
[AC_TRY_LINK(
[#include <math.h>
[AC_TRY_LINK([
#include <math.h>
double glob_double;
],
[double x = 0.0; int res = isinf(x);],
[return isinf(glob_double) ? 0 : 1;],
[ac_cv_func_isinf=yes],
[ac_cv_func_isinf=no])])
@@ -877,8 +878,11 @@ fi
dnl Cannot use AC_CHECK_FUNC because finite may be a macro
AC_MSG_CHECKING(for finite)
AC_TRY_LINK([#include <math.h>],
[int dummy=finite(1.0);],
AC_TRY_LINK([
#include <math.h>
double glob_double;
],
[return finite(glob_double) ? 0 : 1;],
[AC_DEFINE(HAVE_FINITE, 1, [Set to 1 if you have finite()])
AC_MSG_RESULT(yes)],
[AC_MSG_RESULT(no)])