From 52723722c78d0fe474e6f03890d70283e9340bab Mon Sep 17 00:00:00 2001
Message-Id: <52723722c78d0fe474e6f03890d70283e9340bab.1366635207.git.brad.king@kitware.com>
From: Brad King <brad.king@kitware.com>
Date: Mon, 22 Apr 2013 08:50:08 -0400
Subject: [PATCH] Check{C,CXX}CompilerFlag: Test using C locale (#14102)

Set the locale to C while running the compiler for these checks because
we match the resulting warning messages in English only.

Suggested-by: Marco Nolden <m.nolden@dkfz-heidelberg.de>
---
 Modules/CheckCCompilerFlag.cmake   |   12 ++++++++++++
 Modules/CheckCXXCompilerFlag.cmake |   13 +++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/Modules/CheckCCompilerFlag.cmake b/Modules/CheckCCompilerFlag.cmake
index 08e80f7..02f7cb6 100644
--- a/Modules/CheckCCompilerFlag.cmake
+++ b/Modules/CheckCCompilerFlag.cmake
@@ -26,6 +26,12 @@ include(CheckCSourceCompiles)
 macro (CHECK_C_COMPILER_FLAG _FLAG _RESULT)
    set(SAFE_CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS}")
    set(CMAKE_REQUIRED_DEFINITIONS "${_FLAG}")
+   # Normalize locale during test compilation.
+   set(_CheckCCompilerFlag_LOCALE_VARS LC_ALL LC_MESSAGES LANG)
+   foreach(v ${_CheckCCompilerFlag_LOCALE_VARS})
+     set(_CheckCCompilerFlag_SAVED_${v} "$ENV{${v}}")
+     set(ENV{${v}} C)
+   endforeach()
    CHECK_C_SOURCE_COMPILES("int main(void) { return 0; }" ${_RESULT}
      # Some compilers do not fail with a bad flag
      FAIL_REGEX "command line option .* is valid for .* but not for C" # GNU
@@ -41,5 +47,11 @@ macro (CHECK_C_COMPILER_FLAG _FLAG _RESULT)
      FAIL_REGEX "command option .* is not recognized"       # XL
      FAIL_REGEX "WARNING: unknown flag:"                    # Open64
      )
+   foreach(v ${_CheckCCompilerFlag_LOCALE_VARS})
+     set(ENV{${v}} ${_CheckCCompilerFlag_SAVED_${v}})
+     unset(_CheckCCompilerFlag_SAVED_${v})
+   endforeach()
+   unset(_CheckCCompilerFlag_LOCALE_VARS)
+
    set (CMAKE_REQUIRED_DEFINITIONS "${SAFE_CMAKE_REQUIRED_DEFINITIONS}")
 endmacro ()
diff --git a/Modules/CheckCXXCompilerFlag.cmake b/Modules/CheckCXXCompilerFlag.cmake
index 6626403..a872a75 100644
--- a/Modules/CheckCXXCompilerFlag.cmake
+++ b/Modules/CheckCXXCompilerFlag.cmake
@@ -26,6 +26,13 @@ include(CheckCXXSourceCompiles)
 macro (CHECK_CXX_COMPILER_FLAG _FLAG _RESULT)
    set(SAFE_CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS}")
    set(CMAKE_REQUIRED_DEFINITIONS "${_FLAG}")
+
+   # Normalize locale during test compilation.
+   set(_CheckCXXCompilerFlag_LOCALE_VARS LC_ALL LC_MESSAGES LANG)
+   foreach(v ${_CheckCXXCompilerFlag_LOCALE_VARS})
+     set(_CheckCXXCompilerFlag_SAVED_${v} "$ENV{${v}}")
+     set(ENV{${v}} C)
+   endforeach()
    CHECK_CXX_SOURCE_COMPILES("int main() { return 0;}" ${_RESULT}
      # Some compilers do not fail with a bad flag
      FAIL_REGEX "command line option .* is valid for .* but not for C\\\\+\\\\+" # GNU
@@ -43,6 +50,12 @@ macro (CHECK_CXX_COMPILER_FLAG _FLAG _RESULT)
      FAIL_REGEX "File with unknown suffix passed to linker" # PGI
      FAIL_REGEX "WARNING: unknown flag:"                    # Open64
      )
+   foreach(v ${_CheckCXXCompilerFlag_LOCALE_VARS})
+     set(ENV{${v}} ${_CheckCXXCompilerFlag_SAVED_${v}})
+     unset(_CheckCXXCompilerFlag_SAVED_${v})
+   endforeach()
+   unset(_CheckCXXCompilerFlag_LOCALE_VARS)
+
    set (CMAKE_REQUIRED_DEFINITIONS "${SAFE_CMAKE_REQUIRED_DEFINITIONS}")
 endmacro ()
 
-- 
1.7.10.4