chore(build): Migrate existing warning handling to new warnings project

CMakeLists.txt

@@ -31,7 +31,7 @@ option(SVGZ_ICON "Compress the SVG icon of qTox" ON)
 option(ASAN "Compile with AddressSanitizer" OFF)
 option(TSAN "Compile with ThreadSanitizer" OFF)
 option(DESKTOP_NOTIFICATIONS "Use snorenotify for desktop notifications" OFF)
-option(STRICT_OPTIONS "Enable strict compile options, used by CI" OFF)
+option(STRICT_OPTIONS "Error on compile warning, used by CI" OFF)
 
 # process generated files if cmake >= 3.10
 if(POLICY CMP0071)
@@ -93,27 +93,8 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-rtti")
 # Hardening flags (ASLR, warnings, etc)
 set(POSITION_INDEPENDENT_CODE True)
 
-include(CheckCXXCompilerFlag)
-CHECK_CXX_COMPILER_FLAG(-Wweak-vtables COMPILER_SUPPORTS_WARNING_WEAK_VTABLES)
-if(COMPILER_SUPPORTS_WARNING_WEAK_VTABLES)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wweak-vtables")
-endif()
-
-# Extra-strict compile options that we don't want to subject all users to by default
-if (STRICT_OPTIONS)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror")
-endif()
-
-# avoid timestamps in binary for reproducible builds, not added until GCC 4.9
-include(CheckCXXCompilerFlag)
-CHECK_CXX_COMPILER_FLAG(-Wdate-time COMPILER_SUPPORTS_WDATE_TIME)
-if (COMPILER_SUPPORTS_WDATE_TIME)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wdate-time")
-endif()
-
 if (NOT WIN32 AND NOT HAIKU)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstack-protector-all")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wstack-protector")
 endif()
 
 if (UNIX AND NOT APPLE)
@@ -123,7 +104,6 @@ endif()
 
 include(CheckAtomic)
 
-
 # Use ccache when available to speed up builds.
 if (USE_CCACHE)
   find_program(CCACHE_FOUND ccache)

cmake/warnings/CMakeLists.txt

@@ -11,6 +11,10 @@ if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
     endif()
 endif()
 
+include(CheckCXXCompilerFlag)
+CHECK_CXX_COMPILER_FLAG(-Wweak-vtables COMPILER_SUPPORTS_WARNING_WEAK_VTABLES)
+CHECK_CXX_COMPILER_FLAG(-Wdate-time COMPILER_SUPPORTS_WDATE_TIME)
+
 target_compile_options(${PROJECT_NAME} INTERFACE
     $<$<OR:$<BOOL:${CLANG}>,$<CXX_COMPILER_ID:GNU>>:
         -fno-common;
@@ -20,7 +24,6 @@ target_compile_options(${PROJECT_NAME} INTERFACE
         -Wall;
         -Wcast-align;
         -Wdouble-promotion;
-        -Werror;
         -Wextra;
         -Wformat=2;
         -Wmissing-declarations;
@@ -72,4 +75,16 @@ target_compile_options(${PROJECT_NAME} INTERFACE
                  # loss of data # This one is sort of required for gtest.
         /WX;
     >
+    $<$<BOOL:${STRICT_OPTIONS}>:
+        -Werror;
+    >
+    $<$<BOOL:${COMPILER_SUPPORTS_WARNING_WEAK_VTABLES}>:
+        -Wweak-vtables; # https://llvm.org/docs/CodingStandards.html#provide-a-virtual-method-anchor-for-classes-in-headers
+    >
+    $<$<BOOL:${COMPILER_SUPPORTS_WDATE_TIME}>:
+        -Wdate-time; # avoid timestamps in binary for reproducible builds, not added until GCC 4.9
+    >
+    $<$<AND:$<NOT:$<BOOL:${WIN32}>>,$<NOT:$<BOOL:${HAIKU}>>>:
+        -Wstack-protector;
+    >
 )