Fix openal-soft warning flags scope

- target_compile_options(alsoft.common PUBLIC ${C_FLAGS}) propagated
  strict warnings to all dependents.
- Change to PRIVATE so only alsoft.common uses them.

Author: halx99

3rdparty/README.md

@@ -189,7 +189,8 @@
   - Linking `fmt::fmt` instead `alsoft::fmt`
   - Exclude target `alsoft::excommon`
   - Fix `al::char_as_u8/al::u8_as_char` in `common/alstring.hpp` with compiler flag: `-fno-char8_t` or `/Zc:char8_t-`
-  - Disable non‑standard [[clang::nonblocking]] attribute on Win32 to avoid compiler compatibility issues
+  - Disable non‑standard [[clang::nonblocking]] attribute to avoid compiler compatibility issues
+  - Restrict warning flags scope to target: `alsoft.common`
 - License: LGPL-2.1
 
 ## OpenSSL

3rdparty/openal/CMakeLists.txt

@@ -364,8 +364,7 @@ if(MSVC)
     # C4373 - virtual function overrides 'base_function', previous versions of
     #         the compiler did not override when parameters only differed by
     #         const/volatile qualifiers
-    # Axmol spec: Remove /W4 to avoid produces excessive warnings outside Axmol's codebase.
-    list(APPEND C_FLAGS /wd4127 /wd4324 /wd4373 /utf-8 $<$<COMPILE_LANGUAGE:CXX>:/EHsc>)
+    list(APPEND C_FLAGS /W4 /wd4127 /wd4324 /wd4373 /utf-8 $<$<COMPILE_LANGUAGE:CXX>:/EHsc>)
 
     if(NOT DXSDK_DIR)
         string(REGEX REPLACE "\\\\" "/" DXSDK_DIR "$ENV{DXSDK_DIR}")
@@ -1651,7 +1650,7 @@ endif()
 target_include_directories(alsoft.common
     PUBLIC ${OpenAL_BINARY_DIR} ${OpenAL_SOURCE_DIR}/common ${OpenAL_SOURCE_DIR}/gsl/include)
 target_compile_definitions(alsoft.common PUBLIC ${CPP_DEFS})
-target_compile_options(alsoft.common PUBLIC ${C_FLAGS})
+target_compile_options(alsoft.common PRIVATE ${C_FLAGS})
 target_link_libraries(alsoft.common PUBLIC Threads::Threads ${LINKER_FLAGS} fmt::fmt)
 set_target_properties(alsoft.common PROPERTIES ${ALSOFT_STD_VERSION_PROPS}
     POSITION_INDEPENDENT_CODE TRUE)