From 79bb9c8e114aa6d8934407b48cb5a1be3a6531df Mon Sep 17 00:00:00 2001
From: maier <maier@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Mon, 11 Mar 2013 18:16:02 +0000
Subject: [PATCH] CMake: Bugfixes, be more robust in two macros

git-svn-id: https://svn.dealii.org/trunk@28856 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/cmake/macros/macro_add_flags.cmake       |  4 +++-
 .../cmake/macros/macro_enable_if_supported.cmake | 16 +++++++++-------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/deal.II/cmake/macros/macro_add_flags.cmake b/deal.II/cmake/macros/macro_add_flags.cmake
index b3d15f1b14..2bcddaa0a8 100644
--- a/deal.II/cmake/macros/macro_add_flags.cmake
+++ b/deal.II/cmake/macros/macro_add_flags.cmake
@@ -21,6 +21,8 @@
 #
 
 MACRO(ADD_FLAGS _variable _flags)
-  SET(${_variable} "${${_variable}} ${_flags}")
+  IF(NOT "${_flags}" STREQUAL "")
+    SET(${_variable} "${${_variable}} ${_flags}")
+  ENDIF()
 ENDMACRO()
 
diff --git a/deal.II/cmake/macros/macro_enable_if_supported.cmake b/deal.II/cmake/macros/macro_enable_if_supported.cmake
index 817018746c..d843de50da 100644
--- a/deal.II/cmake/macros/macro_enable_if_supported.cmake
+++ b/deal.II/cmake/macros/macro_enable_if_supported.cmake
@@ -21,13 +21,15 @@
 #
 
 MACRO(ENABLE_IF_SUPPORTED _variable _flag)
-  STRING(REGEX REPLACE "^-" "" _flag_name "${_flag}")
-  CHECK_CXX_COMPILER_FLAG(
-    "${_flag}"
-    DEAL_II_HAVE_FLAG_${_flag_name}
-    )
-  IF(DEAL_II_HAVE_FLAG_${_flag_name})
-    SET(${_variable} "${${_variable}} ${_flag}")
+  IF(NOT "${_flag}" STREQUAL "")
+    STRING(REGEX REPLACE "^-" "" _flag_name "${_flag}")
+    CHECK_CXX_COMPILER_FLAG(
+      "${_flag}"
+      DEAL_II_HAVE_FLAG_${_flag_name}
+      )
+    IF(DEAL_II_HAVE_FLAG_${_flag_name})
+      SET(${_variable} "${${_variable}} ${_flag}")
+    ENDIF()
   ENDIF()
 ENDMACRO()
 
-- 
2.39.5