Make it possible to use the C++ headers without CMake

Detect the pointer size solely via the pre-processor

api/sixtyfps-cpp/CMakeLists.txt

@@ -24,13 +24,6 @@ add_library(SixtyFPS INTERFACE)
 add_library(SixtyFPS::SixtyFPS ALIAS SixtyFPS)
 target_link_libraries(SixtyFPS INTERFACE sixtyfps-cpp)
 target_compile_features(SixtyFPS INTERFACE cxx_std_17)
-if (CMAKE_SIZEOF_VOID_P EQUAL 8)
-    target_compile_definitions(SixtyFPS INTERFACE SIXTYFPS_TARGET_64)
-elseif (CMAKE_SIZEOF_VOID_P EQUAL 4)
-    target_compile_definitions(SixtyFPS INTERFACE SIXTYFPS_TARGET_32)
-else()
-    message(FATAL_ERROR "Unsupported CPU target architecture where the pointer size is neiter 4 nor 8")
-endif()
 
 file(GLOB api_headers RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}/include/"
     "${CMAKE_CURRENT_SOURCE_DIR}/include/*.h")

api/sixtyfps-cpp/include/sixtyfps_config.h

@@ -0,0 +1,18 @@
+/* LICENSE BEGIN
+    This file is part of the SixtyFPS Project -- https://sixtyfps.io
+    Copyright (c) 2020 Olivier Goffart <olivier.goffart@sixtyfps.io>
+    Copyright (c) 2020 Simon Hausmann <simon.hausmann@sixtyfps.io>
+
+    SPDX-License-Identifier: GPL-3.0-only
+    This file is also available under commercial licensing terms.
+    Please contact info@sixtyfps.io for more information.
+LICENSE END */
+#pragma once
+
+#include <cstdint>
+
+#if UINTPTR_MAX == 0xFFFFFFFF
+#    define SIXTYFPS_TARGET_32
+#elif UINTPTR_MAX == 0xFFFFFFFFFFFFFFFFu
+#    define SIXTYFPS_TARGET_64
+#endif

xtask/src/cbindgen.rs

@@ -256,6 +256,7 @@ fn gen_corelib(root_dir: &Path, include_dir: &Path) -> anyhow::Result<()> {
     cbindgen::Builder::new()
         .with_config(config)
         .with_src(crate_dir.join("lib.rs"))
+        .with_include("sixtyfps_config.h")
         .with_include("vtable.h")
         .with_include("sixtyfps_string.h")
         .with_include("sixtyfps_sharedvector.h")