Use C99 restrict via pg_restrict, rather than restrict directly.

Unfortunately using 'restrict' plainly causes problems with MSVC,
which supports restrict only as '__restrict'. Defining 'restrict' to
'__restrict' unfortunately causes a conflict with MSVC's usage of
__declspec(restrict) in headers.

Therefore define pg_restrict to the appropriate keyword instead, and
replace existing usages.

This replaces the temporary workaround introduced in 36b4b91ba078.

Author: Andres Freund
Discussion: https://postgr.es/m/2656.1507830907@sss.pgh.pa.us

1 files changed, 61 insertions, 46 deletions

diff --git a/configure b/configure
index 910f0fc3736..cdcb3ceb0c8 100755
--- a/configure
+++ b/configure
@@ -11545,52 +11545,6 @@ _ACEOF
     ;;
 esac
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for C/C++ restrict keyword" >&5
-$as_echo_n "checking for C/C++ restrict keyword... " >&6; }
-if ${ac_cv_c_restrict+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_cv_c_restrict=no
-   # The order here caters to the fact that C++ does not require restrict.
-   for ac_kw in __restrict __restrict__ _Restrict restrict; do
-     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-typedef int * int_ptr;
-	int foo (int_ptr $ac_kw ip) {
-	return ip[0];
-       }
-int
-main ()
-{
-int s[1];
-	int * $ac_kw t = s;
-	t[0] = 0;
-	return foo(t)
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_c_restrict=$ac_kw
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-     test "$ac_cv_c_restrict" != no && break
-   done
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_restrict" >&5
-$as_echo "$ac_cv_c_restrict" >&6; }
-
- case $ac_cv_c_restrict in
-   restrict) ;;
-   no) $as_echo "#define restrict /**/" >>confdefs.h
- ;;
-   *)  cat >>confdefs.h <<_ACEOF
-#define restrict $ac_cv_c_restrict
-_ACEOF
- ;;
- esac
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for printf format archetype" >&5
 $as_echo_n "checking for printf format archetype... " >&6; }
 if ${pgac_cv_printf_archetype+:} false; then :
@@ -12508,6 +12462,67 @@ $as_echo "#define LOCALE_T_IN_XLOCALE 1" >>confdefs.h
 
 fi
 
+# MSVC doesn't cope well with defining restrict to __restrict, the
+# spelling it understands, because it conflicts with
+# __declspec(restrict). Therefore we define pg_restrict to the
+# appropriate definition, which presumably won't conflict.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for C/C++ restrict keyword" >&5
+$as_echo_n "checking for C/C++ restrict keyword... " >&6; }
+if ${ac_cv_c_restrict+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_cv_c_restrict=no
+   # The order here caters to the fact that C++ does not require restrict.
+   for ac_kw in __restrict __restrict__ _Restrict restrict; do
+     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+typedef int * int_ptr;
+	int foo (int_ptr $ac_kw ip) {
+	return ip[0];
+       }
+int
+main ()
+{
+int s[1];
+	int * $ac_kw t = s;
+	t[0] = 0;
+	return foo(t)
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_c_restrict=$ac_kw
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+     test "$ac_cv_c_restrict" != no && break
+   done
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_restrict" >&5
+$as_echo "$ac_cv_c_restrict" >&6; }
+
+ case $ac_cv_c_restrict in
+   restrict) ;;
+   no) $as_echo "#define restrict /**/" >>confdefs.h
+ ;;
+   *)  cat >>confdefs.h <<_ACEOF
+#define restrict $ac_cv_c_restrict
+_ACEOF
+ ;;
+ esac
+
+if test "$ac_cv_c_restrict" = "no" ; then
+  pg_restrict=""
+else
+  pg_restrict="$ac_cv_c_restrict"
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define pg_restrict $pg_restrict
+_ACEOF
+
+
 ac_fn_c_check_type "$LINENO" "struct cmsgcred" "ac_cv_type_struct_cmsgcred" "#include <sys/socket.h>
 #include <sys/param.h>
 #ifdef HAVE_SYS_UCRED_H