Erik's patch to also check for the '__restrict__' or '__restrict' keywords

being recognized by the C compiler as the restrict qualifier.
This closes PR Cactus 1112.


git-svn-id: http://svn.cactuscode.org/flesh/trunk@2990 17b73243-c579-4c4c-a9d2-2d5706c11dac

1 files changed, 16 insertions, 17 deletions

diff --git a/lib/make/configure.in b/lib/make/configure.in
index 1b837a0e..1a82a215 100644
--- a/lib/make/configure.in
+++ b/lib/make/configure.in
@@ -204,25 +204,24 @@ fi
 AC_C_CONST
 AC_C_INLINE
 
-dnl Check for the presence of the restrict keyword
-AC_MSG_CHECKING([for restrict])
-AC_CACHE_VAL(cctk_cv_have_restrict,
-[AC_TRY_COMPILE([
-int foo(double * restrict a, double * restrict b)
-{
-  return 0;
-}],
-, eval "cctk_cv_have_restrict=yes",
-eval "cctk_cv_have_restrict=no")
+dnl Do nothing if the compiler accepts the restrict keyword.
+dnl Otherwise define restrict to __restrict__ or __restrict if one of
+dnl those work, otherwise define restrict to be empty.
+AC_DEFUN(AC_C_RESTRICT,
+[AC_CACHE_CHECK([for restrict], ac_cv_c_restrict,
+[ac_cv_c_restrict=no
+for ac_kw in restrict __restrict__ __restrict; do
+  AC_TRY_COMPILE(, [double * $ac_kw foo;], [ac_cv_c_restrict=$ac_kw; break])
+done
+])
+case "$ac_cv_c_restrict" in
+  restrict | yes) ;;
+  no) AC_DEFINE(restrict, ) ;;
+  *)  AC_DEFINE_UNQUOTED(restrict, $ac_cv_c_restrict) ;;
+esac
 ])
-if test "$cctk_cv_have_restrict" = "yes"; then
-  AC_DEFINE(restrict,restrict)
-  AC_MSG_RESULT(yes)
-else
-  AC_DEFINE(restrict,)
-  AC_MSG_RESULT(no)
-fi
 
+AC_C_RESTRICT
 
 # Check for sizes of integer types