Add platform macros

Author: cschreib

tests/CMakeLists.txt

@@ -1,3 +1,18 @@
+# set OS preprocessor defines
+if(CMAKE_SYSTEM_NAME MATCHES "Emscripten")
+    set(OUP_PLATFORM_WASM TRUE)
+    set(OUP_COMPILER_EMSCRIPTEN TRUE)
+elseif (APPLE)
+    set(OUP_PLATFORM_OSX TRUE)
+elseif (UNIX)
+    set(OUP_PLATFORM_LINUX TRUE)
+elseif (WIN32)
+    set(OUP_PLATFORM_WINDOWS TRUE)
+    if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+        set(OUP_COMPILER_MSVC TRUE)
+    endif()
+endif()
+
 include(FetchContent)
 
 FetchContent_Declare(
@@ -13,6 +28,13 @@ set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${Catch2_SOURCE_DIR}/extras")
 add_executable(oup_tests ${PROJECT_SOURCE_DIR}/tests/runtime_tests.cpp)
 target_link_libraries(oup_tests PRIVATE Catch2::Catch2WithMain)
 target_link_libraries(oup_tests PRIVATE oup::oup)
+target_compile_definitions(oup_tests PRIVATE
+  OUP_PLATFORM_OSX
+  OUP_PLATFORM_WASM
+  OUP_PLATFORM_LINUX
+  OUP_PLATFORM_WINDOWS
+  OUP_COMPILER_MSVC
+  OUP_COMPILER_EMSCRIPTEN)
 
 include(CTest)
 include(Catch)

tests/runtime_tests.cpp

@@ -10,10 +10,14 @@ std::size_t num_allocations = 0u;
 std::size_t double_delete = 0u;
 bool memory_tracking = false;
 
-// NB: getting weird errors on MacOS when doing this
-#if !defined(__APPLE__)
-void* operator new(size_t size)
-{
+#if defined(OUP_PLATFORM_OSX)
+// Getting weird errors on MacOS when overriding operator new and delete,
+// so disable the memory leak checking for this platform.
+#   define CHECK_MEMORY_LEAKS 0
+#endif
+
+#if defined(CHECK_MEMORY_LEAKS) && CHECK_MEMORY_LEAKS
+void* allocate(std::size_t size, bool array) {
     if (memory_tracking && num_allocations == max_allocations) {
         throw std::bad_alloc();
     }