cmake: Refactor detection of operating system

Add new module WaffleDefineOS that defines booleans `waffle_on_linux`
and `waffle_on_mac`. Replace each check on CMAKE_SYSTEM_NAME with
a check on one of these new bools.

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>

9 files changed, 44 insertions, 11 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7a809c5..a6695fe 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,6 +29,7 @@ cmake_minimum_required(VERSION 2.8)
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake/Modules")
 
+include(WaffleDefineOS)
 include(Options.cmake)
 include(WaffleDefineInternalOptions)
 include(WaffleValidateOptions)
diff --git a/Options.cmake b/Options.cmake
index cc50dc5..923505b 100644
--- a/Options.cmake
+++ b/Options.cmake
@@ -1,4 +1,4 @@
-if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
+if(waffle_on_linux)
     # On Linux, you must enable at least one of the below options.
     option(waffle_has_glx "Build support for GLX" OFF)
     option(waffle_has_wayland "Build support for Wayland" OFF)
diff --git a/cmake/Modules/WaffleDefineCompilerFlags.cmake b/cmake/Modules/WaffleDefineCompilerFlags.cmake
index b2628df..0f4cdec 100644
--- a/cmake/Modules/WaffleDefineCompilerFlags.cmake
+++ b/cmake/Modules/WaffleDefineCompilerFlags.cmake
@@ -29,7 +29,7 @@ set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} --std=c99")
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror=implicit-function-declaration")
 
-if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
+if(waffle_on_linux)
     # On MacOS, the SSE2 headers trigger this error.
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror=missing-prototypes")
 endif()
@@ -50,7 +50,7 @@ if(waffle_has_tls_model_initial_exec)
     add_definitions(-DWAFFLE_HAS_TLS_MODEL_INITIAL_EXEC)
 endif()
 
-if("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
+if(waffle_on_mac)
     add_definitions(-DWAFFLE_HAS_CGL)
 endif()
 
diff --git a/cmake/Modules/WaffleDefineOS.cmake b/cmake/Modules/WaffleDefineOS.cmake
new file mode 100644
index 0000000..e437947
--- /dev/null
+++ b/cmake/Modules/WaffleDefineOS.cmake
@@ -0,0 +1,32 @@
+# Copyright 2013 Intel Corporation
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# - Redistributions of source code must retain the above copyright notice, this
+#   list of conditions and the following disclaimer.
+#
+# - Redistributions in binary form must reproduce the above copyright notice,
+#   this list of conditions and the following disclaimer in the documentation
+#   and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
+    set(waffle_on_linux true)
+elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
+    set(waffle_on_mac true)
+else()
+    message(FATAL_ERROR "Unrecognized CMAKE_SYSTEM_NAME=\"${CMAKE_SYSTEM_NAME|\"")
+endif()
diff --git a/cmake/Modules/WaffleFindDependencies.cmake b/cmake/Modules/WaffleFindDependencies.cmake
index 498d775..8fb9d2a 100644
--- a/cmake/Modules/WaffleFindDependencies.cmake
+++ b/cmake/Modules/WaffleFindDependencies.cmake
@@ -25,7 +25,7 @@
 
 find_package(PkgConfig)
 
-if("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
+if(waffle_on_mac)
     find_package(OpenGL REQUIRED)
     find_library(COCOA_FRAMEWORK Cocoa REQUIRED)
     find_library(CORE_FOUNDATION_FRAMEWORK CoreFoundation REQUIRED)
diff --git a/cmake/Modules/WaffleValidateOptions.cmake b/cmake/Modules/WaffleValidateOptions.cmake
index 8bc7d16..03eb4ba 100644
--- a/cmake/Modules/WaffleValidateOptions.cmake
+++ b/cmake/Modules/WaffleValidateOptions.cmake
@@ -44,7 +44,7 @@ if(DEFINED waffle_install_docdir)
             "details.")
 endif()
 
-if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
+if(waffle_on_linux)
     if(NOT waffle_has_glx AND NOT waffle_has_wayland AND
        NOT waffle_has_x11_egl AND NOT waffle_has_gbm)
         message(FATAL_ERROR
@@ -52,7 +52,7 @@ if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
                 "waffle_has_glx, waffle_has_wayland, "
                 "waffle_has_x11_egl, waffle_has_gbm.")
     endif()
-elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
+elseif(waffle_on_mac)
     if(waffle_has_gbm)
         message(FATAL_ERROR "Option is not supported on Darwin: waffle_has_gbm.")
     endif()
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index eb09669..48147f9 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -7,7 +7,7 @@ install(FILES Makefile.example
 # Target: simple-x11-egl (executable)
 # ----------------------------------------------------------------------------
 
-if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
+if(waffle_on_linux)
     add_executable(simple-x11-egl simple-x11-egl.c)
     target_link_libraries(simple-x11-egl ${waffle_libname})
 endif()
@@ -19,7 +19,7 @@ endif()
 add_executable(gl_basic gl_basic.c)
 target_link_libraries(gl_basic ${waffle_libname})
 
-if("${CMAKE_SYSTEM_NAME}" STREQUAL Darwin)
+if(waffle_on_mac)
     set_target_properties(gl_basic
         PROPERTIES
         COMPILE_FLAGS "-ObjC"
diff --git a/src/waffle/CMakeLists.txt b/src/waffle/CMakeLists.txt
index cdb8981..a743096 100644
--- a/src/waffle/CMakeLists.txt
+++ b/src/waffle/CMakeLists.txt
@@ -59,7 +59,7 @@ set(waffle_sources
     core/wcore_util.c
     )
 
-if("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
+if(waffle_on_mac)
     list(APPEND waffle_sources
         cgl/cgl_config.m
         cgl/cgl_context.m
@@ -98,7 +98,7 @@ if(waffle_has_glx)
         )
 endif()
 
-if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
+if(waffle_on_linux)
     list(APPEND waffle_sources
         linux/linux_dl.c
         linux/linux_platform.c
diff --git a/tests/functional/CMakeLists.txt b/tests/functional/CMakeLists.txt
index dbf481c..6ad923d 100644
--- a/tests/functional/CMakeLists.txt
+++ b/tests/functional/CMakeLists.txt
@@ -7,7 +7,7 @@ set(gl_basic_test_sources
     gl_basic_test.c
     )
 
-if("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
+if(waffle_on_mac)
     list(APPEND gl_basic_test_sources
         gl_basic_cocoa.m
         )