Adding upstream version 4.2.2.upstream/4.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/cmake/modules/CheckCLinkerFlag.cmake b/cmake/modules/CheckCLinkerFlag.cmake
new file mode 100644
index 0000000..f21d573
--- /dev/null
+++ b/cmake/modules/CheckCLinkerFlag.cmake
@@ -0,0 +1,57 @@
+# - Check whether the C linker supports a given flag.
+# CHECK_C_LINKER_FLAG(FLAG VARIABLE)
+#
+#  FLAG - the compiler flag
+#  VARIABLE - variable to store the result
+# 
+#  This actually calls the check_c_source_compiles macro.
+#  See help for CheckCSourceCompiles for a listing of variables
+#  that can modify the build.
+
+# Copyright (c) 2010, Joerg Mayer (see AUTHORS file)
+#
+# Redistribution and use is allowed according to the terms of the BSD license.
+
+INCLUDE(CheckCSourceRuns)
+
+MACRO (CHECK_C_LINKER_FLAG _FLAG _RESULT)
+   #
+   # This is ugly.
+   #
+   # See CMake bug 0015934:
+   #
+   #    https://cmake.org/Bug/view.php?id=15934
+   #
+   # So we add the flags to CMAKE_REQUIRED_LIBRARIES, to sneak it into
+   # the linker flags.
+   #
+   # This may or may not work with versions earlier than 2.8.11, although
+   # 2.8.10's Xcode generator doesn't appear to work at all - it fails
+   # with an internal CMake error.
+   #
+   # With 3.2 and later, we could also set policy CMP0056 to NEW and
+   # set CMAKE_EXE_LINKER_FLAGS.
+   #
+   set(save_CMAKE_REQUIRED_LIBRARIES "${CMAKE_REQUIRED_LIBRARIES}")
+   set(CMAKE_REQUIRED_LIBRARIES "${_FLAG}")
+   if(CMAKE_C_COMPILER_ID MATCHES "MSVC")
+      #
+      # This means the linker is presumably the Microsoft linker;
+      # we need to pass /WX in order to have the linker fail,
+      # rather than just complaining and driving on, if it's
+      # passed a flag it doesn't handle.
+      #
+      set(CMAKE_REQUIRED_LIBRARIES "/WX ${CMAKE_REQUIRED_LIBRARIES}")
+   elseif(CMAKE_C_COMPILER_ID MATCHES "Clang")
+      #
+      # We'll be running the linker through the compiler driver, so
+      # we may need to pass -Werror=unused-command-line-argument to have it
+      # fail, rather than just complaining and driving on, if it's
+      # passed a flag it doesn't handle.
+      set(CMAKE_REQUIRED_LIBRARIES
+         "-Werror=unused-command-line-argument ${CMAKE_REQUIRED_LIBRARIES}")
+   endif()
+   check_c_source_compiles("int main(void) { return 0;}" ${_RESULT})
+   set(CMAKE_REQUIRED_LIBRARIES "${save_CMAKE_REQUIRED_LIBRARIES}")
+ENDMACRO (CHECK_C_LINKER_FLAG)
+