Force "restrict" not to be used when compiling with xlc.

Per buildfarm animal Hornet and followup manual testing by Noah Misch,
it appears xlc miscompiles code using "restrict" in at least some
cases. Allow disabling restrict usage with FORCE_DISABLE_RESTRICT=yes
in template files, and do so for aix/xlc.

Author: Andres Freund and Tom Lane
Discussion: https://postgr.es/m/1820.1507918762@sss.pgh.pa.us

diff --git a/configure b/configure
index cdcb3ceb0c80e888941785491c44369b56dc911b..4ecd2e19224c187d2fa98d6cb7e093bd4556c231 100755 (executable)
--- a/configure
+++ b/configure
@@ -12466,6 +12466,10 @@ fi
 # spelling it understands, because it conflicts with
 # __declspec(restrict). Therefore we define pg_restrict to the
 # appropriate definition, which presumably won't conflict.
+#
+# Allow platforms with buggy compilers to force restrict to not be
+# used by setting $FORCE_DISABLE_RESTRICT=yes in the relevant
+# template.
 { $as_echo "$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 :
@@ -12512,7 +12516,7 @@ _ACEOF
  ;;
  esac
 
-if test "$ac_cv_c_restrict" = "no" ; then
+if test "$ac_cv_c_restrict" = "no" -o "x$FORCE_DISABLE_RESTRICT" = "xyes"; then
   pg_restrict=""
 else
   pg_restrict="$ac_cv_c_restrict"

diff --git a/configure.in b/configure.in
index 32bb7bf940d2792f2e6a82da760196cae2ed95f8..cea7fd075534d632cafa7b403f27a86a51f1a047 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -1329,8 +1329,12 @@ PGAC_TYPE_LOCALE_T
 # spelling it understands, because it conflicts with
 # __declspec(restrict). Therefore we define pg_restrict to the
 # appropriate definition, which presumably won't conflict.
+#
+# Allow platforms with buggy compilers to force restrict to not be
+# used by setting $FORCE_DISABLE_RESTRICT=yes in the relevant
+# template.
 AC_C_RESTRICT
-if test "$ac_cv_c_restrict" = "no" ; then
+if test "$ac_cv_c_restrict" = "no" -o "x$FORCE_DISABLE_RESTRICT" = "xyes"; then
   pg_restrict=""
 else
   pg_restrict="$ac_cv_c_restrict"

diff --git a/src/template/aix b/src/template/aix
index b566ff129df6008b28d3b90470371e30e4f4adb4..ed832849dae984f72145527d59b53c7307e3ee90 100644 (file)
--- a/src/template/aix
+++ b/src/template/aix
@@ -10,6 +10,10 @@ if test "$GCC" != yes ; then
       CFLAGS="-O2 -qmaxmem=16384 -qsrcmsg"
       ;;
   esac
+
+  # Due to a compiler bug, see 20171013023536.GA492146@rfd.leadboat.com for details,
+  # force restrict not to be used when compiling with xlc.
+  FORCE_DISABLE_RESTRICT=yes
 fi
 
 # Native memset() is faster, tested on: