From db8ebd33ad899db5fff41fe4c7749783e540ca92 Mon Sep 17 00:00:00 2001
From: Ralph Castain <rhc@open-mpi.org>
Date: Mon, 18 Dec 2017 19:18:53 -0800
Subject: [PATCH] Fix the optnone attribute, add extension attribute

See how the various compilers handle these

Signed-off-by: Ralph Castain <rhc@open-mpi.org>
---
 config/opal_check_attributes.m4   | 10 +++++++++-
 opal/include/opal_config_bottom.h |  6 ++++++
 orte/orted/orted_submit.c         |  2 +-
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/config/opal_check_attributes.m4 b/config/opal_check_attributes.m4
index 9a23251d7b3..cd9acf6b4e2 100644
--- a/config/opal_check_attributes.m4
+++ b/config/opal_check_attributes.m4
@@ -561,12 +561,18 @@ AC_DEFUN([OPAL_CHECK_ATTRIBUTES], [
 
     _OPAL_CHECK_SPECIFIC_ATTRIBUTE([optnone],
         [
-        void foo(void) __attribute__ ((__optnone__));
+        void __attribute__ ((__optnone__)) foo(void);
         void foo(void) { return ; }
         ],
         [],
         [])
 
+    _OPAL_CHECK_SPECIFIC_ATTRIBUTE([extension],
+        [
+         #define FOO __extension__ ({size_t bar; bar = 3;})
+        ],
+        [],
+        [])
   fi
 
   # Now that all the values are set, define them
@@ -621,4 +627,6 @@ AC_DEFUN([OPAL_CHECK_ATTRIBUTES], [
                      [Whether your compiler has __attribute__ destructor or not])
   AC_DEFINE_UNQUOTED(OPAL_HAVE_ATTRIBUTE_OPTNONE, [$opal_cv___attribute__optnone],
                      [Whether your compiler has __attribute__ optnone or not])
+  AC_DEFINE_UNQUOTED(OPAL_HAVE_ATTRIBUTE_EXTENSION, [$opal_cv___attribute__extension],
+                     [Whether your compiler has __attribute__ extension or not])
 ])
diff --git a/opal/include/opal_config_bottom.h b/opal/include/opal_config_bottom.h
index c913c1f5107..58823471774 100644
--- a/opal/include/opal_config_bottom.h
+++ b/opal/include/opal_config_bottom.h
@@ -240,6 +240,12 @@
 #    define __opal_attribute_optnone__
 #endif
 
+#if OPAL_HAVE_ATTRIBUTE_EXTENSION
+#    define __opal_attribute_extension__    __extension__
+#else
+#    define __opal_attribute_extension__
+#endif
+
 #  if OPAL_C_HAVE_VISIBILITY
 #    define OPAL_DECLSPEC           __opal_attribute_visibility__("default")
 #    define OPAL_MODULE_DECLSPEC    __opal_attribute_visibility__("default")
diff --git a/orte/orted/orted_submit.c b/orte/orted/orted_submit.c
index 5c5f5fc4ae0..f4c350bc02a 100644
--- a/orte/orted/orted_submit.c
+++ b/orte/orted/orted_submit.c
@@ -173,7 +173,7 @@ char MPIR_attach_fifo[MPIR_MAX_PATH_LENGTH] = {0};
 int MPIR_force_to_main = 0;
 static void orte_debugger_init_before_spawn(orte_job_t *jdata);
 
-ORTE_DECLSPEC void* MPIR_Breakpoint(void)  __opal_attribute_optnone__;
+ORTE_DECLSPEC void* __opal_attribute_optnone__ MPIR_Breakpoint(void);
 
 /*
  * Breakpoint function for parallel debuggers