#1217 Read compiler informations from Path file, with possibility to override from command line.

CMakeLists.txt

@@ -2,7 +2,25 @@
 cmake_minimum_required(VERSION 3.8)
 
 # TODO Add check whether the provided value is valid.
+
+
+# ===================================================================================================================
+# Include a file with default setting. Some of them might be overriden by command line, such as the C or C++ compiler.
+# ===================================================================================================================
+if(NOT PATH_FILE)
+    message(FATAL_ERROR "-DPATH_FILE must be present in the command line and point to a file that specify the paths and settings to use in the build. A default one is defined in cmake/Paths.cmake; feel free to copy and adapt it to your needs.")
+endif()
+
+include(${PATH_FILE})
+
+
+# ===================================================================================================================
+# Set some values in the path file that night be overridden by cache variables.
+# WARNING: all those calls must occur BEFORE the call to project, so that overriding remains possible.
+# ===================================================================================================================
+
 # From https://cmake.org/pipermail/cmake/2008-September/023808.html
+# Ensure if the user doesn't specify arenything in command line debug is chosen (CMake default is no optimization and no debug symbol, which is rather useless).
 if(DEFINED CMAKE_BUILD_TYPE)
    set(CMAKE_BUILD_TYPE ${CMAKE_BUILD_TYPE} CACHE STRING "Choose the type of
 build, options are: None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used) Debug
@@ -13,11 +31,19 @@ options are: None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used) Debug Release
 RelWithDebInfo MinSizeRel.")
 endif()
 
+# Set C and CXX compilers from the values read in the setting file. Might be overridden in command line.
+set(CMAKE_C_COMPILER ${CC} CACHE STRING "C compiler (or the Mpi wrapper over it).")
+set(CMAKE_CXX_COMPILER ${CXX} CACHE STRING "C++ compiler (or the Mpi wrapper over it).")
 
+
+# ===================================================================================================================
+# Set project.
+# ===================================================================================================================
 project( "MoReFEM_CMAKE")
 
 set_property(GLOBAL PROPERTY USE_FOLDERS OFF)
 
+
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
@@ -28,11 +54,7 @@ MESSAGE("Module path: ${CMAKE_MODULE_PATH}")
 
 include(CustomCommands)
 
-if(NOT PATH_FILE)
-    message(FATAL_ERROR "-DPATH_FILE must be present in the command line and point to a file that specify the paths and settings to use in the build. A default one is defined in cmake/Paths.cmake; feel free to copy and adapt it to your needs.")
-endif()
 
-include(${PATH_FILE})
 
 # All --all_load in target_link_libraries of executables if STATIC library are chose.
     
@@ -55,11 +77,6 @@ else()
     set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
 endif()        
 
-
-message("CMAKE_C_COMPILER " ${CMAKE_C_COMPILER})
-message("CMAKE_C_COMPILER_ID" ${CMAKE_C_COMPILER_ID})
-
-
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}/Sources /
                     ${CMAKE_CURRENT_SOURCE_DIR}/Sources/ThirdParty/Source/Tclap/include /
                     ${OPS_DIR} /

cmake/Compiler.cmake

@@ -16,7 +16,7 @@ if(${CMAKE_C_COMPILER_ID} STREQUAL "AppleClang" OR ${CMAKE_C_COMPILER_ID} STREQU
     add_cxx_compiler_flag("-stdlib=libc++") 
     
     if (${CMAKE_BUILD_TYPE} STREQUAL "Debug")
-        add_definitions("_LIBCPP_DEBUG2=0") # Additional checks such as index out of bounds in vectors in libc++; might 
+        add_definitions(-D_LIBCPP_DEBUG2=0) # Additional checks such as index out of bounds in vectors in libc++; might 
                                             # be removed at any point from libc++.
     endif()
     

cmake/Paths.cmake

 # Choose C and C++ compilers. You might also specifies here clang static analyzer (paths to ccc-analyzer and c++-analyzer respectively) to perform static analysis of the code.
-set(COMPILER 'clang )
-set(COMPILER_DIRECTORY 'clang )
-set(CC /Users/Shared/LibraryVersions/clang/Openmpi/bin/mpicc )
-set(CXX /Users/Shared/LibraryVersions/clang/Openmpi/bin/mpic++ )
+set(CC /Users/Shared/LibraryVersions/llvm-clang/Openmpi/bin/mpicc )
+set(CXX /Users/Shared/LibraryVersions/llvm-clang/Openmpi/bin/mpic++ )
 
 # Choose either 'debug' or 'release'.
 set(MODE debug)