Define and use variables for all supported compilers

1 files changed, 27 insertions, 13 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bd0455223e..6df3f12649 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -19,10 +19,33 @@ if(POLICY CMP0025)
 endif()
 set(CMAKE_POLICY_WARNING_CMP0025 ON)
 
+#######################################################################
+# Compilers and toolchains
+
+if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  # GNU is GNU GCC
+  set(GNU_GCC true)
+else()
+  set(GNU_GCC false)
+endif()
+
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  # using regular Clang or AppleClang
+  set(CLANG true)
+else()
+  set(CLANG false)
+endif()
+
+# CMake implicitly sets the variable MSVC to true for Microsoft
+# Visual C++ or another compiler simulating Visual C++.
+# https://cmake.org/cmake/help/latest/variable/MSVC.html
+
+#######################################################################
+
 set(CMAKE_CXX_STANDARD 17)
 
 # Speed up builds on HDDs
-if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU") # GNU is GNU GCC
+if(GNU_GCC)
   add_compile_options(-pipe)
 endif()
 
@@ -112,8 +135,7 @@ else()
   endif()
   cmake_dependent_option(CCACHE_SUPPORT "Enable ccache support" ON "CCACHE_EXECUTABLE" OFF)
   if(CCACHE_SUPPORT)
-    if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" # GNU is GNU GCC
-      OR "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang") # either "AppleClang" or "Clang"
+    if(GNU_GCC OR CLANG)
       # without this compiler messages in `make` backend would be uncolored
       set(CMAKE_CXX_FLAGS  "${CMAKE_CXX_FLAGS} -fdiagnostics-color=auto")
     endif()
@@ -137,13 +159,6 @@ if(CMAKE_VERSION VERSION_LESS "3.7.0")
   set(CMAKE_INCLUDE_CURRENT_DIR ON)
 endif()
 
-if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-  # using regular Clang or AppleClang
-  set(CLANG ON)
-else()
-  set(CLANG OFF)
-endif()
-
 # Mixxx itself
 add_library(mixxx-lib STATIC EXCLUDE_FROM_ALL
   src/analyzer/analyzerbeats.cpp
@@ -712,8 +727,7 @@ if(UNIX AND NOT APPLE)
 endif()
 
 # Disable warnings in generated source files
-if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" # GNU is GNU GCC
-  OR "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang") # either "AppleClang" or "Clang"
+if(GNU_GCC OR CLANG)
   set_property(
     SOURCE src/library/rekordbox/rekordbox_anlz.cpp
     APPEND_STRING
@@ -2049,7 +2063,7 @@ if(NOT OPTIMIZE STREQUAL "off")
     else()
       message(FATAL_ERROR "Invalid value passed to OPTIMIZE option: ${OPTIMIZE}")
     endif()
-  elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  elseif(GNU_GCC)
     # Common flags to all optimizations.
     # -ffast-math will prevent a performance penalty by denormals
     # (floating point values almost Zero are treated as Zero)