Implement C++17 aligned-new support for macOS < 10.14

cmake/SfizzConfig.cmake

@@ -1,6 +1,7 @@
 include(CMakeDependentOption)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
+include(CheckCXXSourceCompiles)
 include(GNUWarnings)
 
 set(CMAKE_CXX_STANDARD 11 CACHE STRING "C++ standard to be used")
@@ -52,7 +53,30 @@ endif()
 
 # Set macOS compatibility level
 if(APPLE)
-    set(CMAKE_OSX_DEPLOYMENT_TARGET "10.14")
+    set(CMAKE_OSX_DEPLOYMENT_TARGET "10.9")
+endif()
+
+# If using C++17, check if aligned-new has runtime support on the platform;
+# on macOS, this depends on the deployment target.
+if(CMAKE_CXX_STANDARD LESS 17)
+    # not necessary on older C++, it will call ordinary new and delete
+    set(SFIZZ_IMPLEMENT_CXX17_ALIGNED_NEW_SUPPORT FALSE)
+else()
+    check_cxx_source_compiles("
+struct Test { alignas(1024) int z; };
+int main() { new Test; return 0; }
+" SFIZZ_HAVE_CXX17_ALIGNED_NEW)
+    # if support is absent, sfizz will provide a substitute implementation
+    if(SFIZZ_HAVE_CXX17_ALIGNED_NEW)
+        set(SFIZZ_IMPLEMENT_CXX17_ALIGNED_NEW_SUPPORT FALSE)
+    else()
+        # on macOS, this mandatory flag tells that allocation functions are user-provided
+        check_cxx_compiler_flag("-faligned-allocation" SFIZZ_HAVE_CXXFLAG_FALIGNED_ALLOCATION)
+        if(SFIZZ_HAVE_CXXFLAG_FALIGNED_ALLOCATION)
+            add_compile_options("$<$<COMPILE_LANGUAGE:CXX>:-faligned-allocation>")
+        endif()
+        set(SFIZZ_IMPLEMENT_CXX17_ALIGNED_NEW_SUPPORT TRUE)
+    endif()
 endif()
 
 # Do not define macros `min` and `max`

src/CMakeLists.txt

@@ -193,7 +193,8 @@ set(SFIZZ_SOURCES
     sfizz/effects/impl/ResonantStringAVX.cpp
     sfizz/effects/impl/ResonantArray.cpp
     sfizz/effects/impl/ResonantArraySSE.cpp
-    sfizz/effects/impl/ResonantArrayAVX.cpp)
+    sfizz/effects/impl/ResonantArrayAVX.cpp
+    sfizz/utility/c++17/AlignedMemorySupport.cpp)
 
 include(SfizzSIMDSourceFiles)
 sfizz_add_simd_sources(SFIZZ_SOURCES ".")
@@ -303,6 +304,9 @@ endif()
 if(SFIZZ_RELEASE_ASSERTS)
     target_compile_definitions(sfizz_internal PUBLIC "SFIZZ_ENABLE_RELEASE_ASSERT=1")
 endif()
+if(SFIZZ_IMPLEMENT_CXX17_ALIGNED_NEW_SUPPORT)
+    target_compile_definitions(sfizz_internal PRIVATE "SFIZZ_IMPLEMENT_CXX17_ALIGNED_NEW_SUPPORT=1")
+endif()
 sfizz_enable_fast_math(sfizz_internal)
 
 # Check that sfizz and cmake-side definitions are matching

src/sfizz/utility/c++17/AlignedMemorySupport.cpp

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: BSD-2-Clause
+
+// This code is part of the sfizz library and is licensed under a BSD 2-clause
+// license. You should have receive a LICENSE.md file along with the code.
+// If not, contact the sfizz maintainers at https://github.com/sfztools/sfizz
+
+#if defined(SFIZZ_IMPLEMENT_CXX17_ALIGNED_NEW_SUPPORT)
+#include <new>
+#if defined(_WIN32)
+#   include <malloc.h>
+#else
+#   include <stdlib.h>
+#endif
+
+void* operator new(std::size_t count, std::align_val_t al, const std::nothrow_t&) noexcept
+{
+    void *ptr;
+#if defined(_WIN32)
+    ptr = ::_aligned_malloc(count, static_cast<std::size_t>(al));
+#else
+    if (::posix_memalign(&ptr, static_cast<std::size_t>(al), count) != 0)
+        ptr = nullptr;
+#endif
+    return ptr;
+}
+
+void operator delete(void* ptr, std::align_val_t, const std::nothrow_t&) noexcept
+{
+#if defined(_WIN32)
+    ::_aligned_free(ptr);
+#else
+    ::free(ptr);
+#endif
+}
+
+//------------------------------------------------------------------------------
+
+void* operator new(std::size_t count, std::align_val_t al)
+{
+    void *ptr = operator new(count, al, std::nothrow);
+    if (!ptr)
+        throw std::bad_alloc();
+    return ptr;
+}
+
+void operator delete(void* ptr, std::align_val_t al) noexcept
+{
+    operator delete(ptr, al, std::nothrow);
+}
+
+//------------------------------------------------------------------------------
+
+void* operator new[](std::size_t count, std::align_val_t al)
+{
+    return operator new(count, al);
+}
+
+void* operator new[](std::size_t count, std::align_val_t al, const std::nothrow_t& tag) noexcept
+{
+    return operator new(count, al, tag);
+}
+
+void operator delete[](void* ptr, std::align_val_t al) noexcept
+{
+    operator delete(ptr, al);
+}
+
+void operator delete[](void* ptr, std::align_val_t al, const std::nothrow_t& tag) noexcept
+{
+    operator delete(ptr, al, tag);
+}
+
+
+#endif // defined(SFIZZ_IMPLEMENT_CXX17_ALIGNED_NEW_SUPPORT)