cmake: make SDL_CPU_xxx variable visible when using CMAKE_OSX_ARCHITECTURES

(cherry picked from commit ebb52973e1)

CMakeLists.txt

@@ -79,6 +79,12 @@ include("${SDL3_SOURCE_DIR}/cmake/PreseedEmscriptenCache.cmake")
 
 SDL_DetectCompiler()
 SDL_DetectTargetCPUArchitectures(SDL_CPUS)
+if(APPLE AND CMAKE_OSX_ARCHITECTURES)
+  list(LENGTH CMAKE_OSX_ARCHITECTURES _num_arches)
+  if(_num_arches GREATER 1)
+    set(APPLE_MULTIARCH TRUE)
+  endif()
+endif()
 
 # Increment this if there is an incompatible change - but if that happens,
 # we should rename the library from SDL3 to SDL4, at which point this would
@@ -350,7 +356,7 @@ dep_option(SDL_WASAPI              "Use the Windows WASAPI audio driver" ON "WIN
 dep_option(SDL_RENDER_D3D          "Enable the Direct3D 9 render driver" ON "SDL_RENDER;SDL_DIRECTX" OFF)
 dep_option(SDL_RENDER_D3D11        "Enable the Direct3D 11 render driver" ON "SDL_RENDER;SDL_DIRECTX" OFF)
 dep_option(SDL_RENDER_D3D12        "Enable the Direct3D 12 render driver" ON "SDL_RENDER;SDL_DIRECTX" OFF)
-dep_option(SDL_RENDER_METAL        "Enable the Metal render driver" ON "SDL_RENDER;${APPLE}" OFF)
+dep_option(SDL_RENDER_METAL        "Enable the Metal render driver" ON "SDL_RENDER;APPLE" OFF)
 dep_option(SDL_RENDER_GPU          "Enable the SDL_GPU render driver" ON "SDL_RENDER;SDL_GPU" OFF)
 dep_option(SDL_VIVANTE             "Use Vivante EGL video driver" ON "${UNIX_SYS};SDL_CPU_ARM32" OFF)
 dep_option(SDL_VULKAN              "Enable Vulkan support" ON "SDL_VIDEO;ANDROID OR APPLE OR LINUX OR FREEBSD OR WINDOWS" OFF)
@@ -658,7 +664,7 @@ if(SDL_ASSEMBLY)
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -mmmx")
     endif()
-    check_c_source_compiles("
+    check_x86_source_compiles([==[
       #include <mmintrin.h>
       void ints_add(int *dest, int *a, int *b, unsigned size) {
         for (; size >= 2; size -= 2, dest += 2, a += 2, b += 2) {
@@ -668,7 +674,7 @@ if(SDL_ASSEMBLY)
       int main(int argc, char *argv[]) {
         ints_add((int*)0, (int*)0, (int*)0, 0);
         return 0;
-      }" COMPILER_SUPPORTS_MMX)
+      }]==] COMPILER_SUPPORTS_MMX)
     cmake_pop_check_state()
     if(COMPILER_SUPPORTS_MMX)
       set(HAVE_MMX TRUE)
@@ -679,7 +685,7 @@ if(SDL_ASSEMBLY)
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -msse")
     endif()
-    check_c_source_compiles("
+    check_x86_source_compiles([==[
       #include <xmmintrin.h>
       void floats_add(float *dest, float *a, float *b, unsigned size) {
         for (; size >= 4; size -= 4, dest += 4, a += 4, b += 4) {
@@ -689,7 +695,7 @@ if(SDL_ASSEMBLY)
       int main(int argc, char **argv) {
         floats_add((float*)0, (float*)0, (float*)0, 0);
         return 0;
-      }" COMPILER_SUPPORTS_SSE)
+      }]==] COMPILER_SUPPORTS_SSE)
     cmake_pop_check_state()
     if(COMPILER_SUPPORTS_SSE)
       set(HAVE_SSE TRUE)
@@ -700,7 +706,7 @@ if(SDL_ASSEMBLY)
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -msse2")
     endif()
-    check_c_source_compiles("
+    check_x86_source_compiles([==[
       #include <emmintrin.h>
       void doubles_add(double *dest, double *a, double *b, unsigned size) {
         for (; size >= 4; size -= 4, dest += 4, a += 4, b += 4) {
@@ -710,7 +716,7 @@ if(SDL_ASSEMBLY)
       int main(int argc, char **argv) {
         doubles_add((double*)0, (double*)0, (double*)0, 0);
         return 0;
-      }" COMPILER_SUPPORTS_SSE2)
+      }]==] COMPILER_SUPPORTS_SSE2)
     cmake_pop_check_state()
     if(COMPILER_SUPPORTS_SSE2)
       set(HAVE_SSE2 TRUE)
@@ -721,7 +727,7 @@ if(SDL_ASSEMBLY)
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -msse3")
     endif()
-    check_c_source_compiles("
+    check_x86_source_compiles([==[
       #include <pmmintrin.h>
       void ints_add(int *dest, int *a, int *b, unsigned size) {
         for (; size >= 4; size -= 4, dest += 4, a += 4, b += 4) {
@@ -731,7 +737,7 @@ if(SDL_ASSEMBLY)
       int main(int argc, char **argv) {
         ints_add((int*)0, (int*)0, (int*)0, 0);
         return 0;
-      }" COMPILER_SUPPORTS_SSE3)
+      }]==] COMPILER_SUPPORTS_SSE3)
     cmake_pop_check_state()
     if(COMPILER_SUPPORTS_SSE3)
       set(HAVE_SSE3 TRUE)
@@ -742,7 +748,7 @@ if(SDL_ASSEMBLY)
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -msse4.1")
     endif()
-    check_c_source_compiles("
+    check_x86_source_compiles([==[
       #include <smmintrin.h>
       void ints_mul(int *dest, int *a, int *b, unsigned size) {
         for (; size >= 4; size -= 4, dest += 4, a += 4, b += 4) {
@@ -752,7 +758,7 @@ if(SDL_ASSEMBLY)
       int main(int argc, char **argv) {
         ints_mul((int*)0, (int*)0, (int*)0, 0);
         return 0;
-      }" COMPILER_SUPPORTS_SSE4_1)
+      }]==] COMPILER_SUPPORTS_SSE4_1)
     cmake_pop_check_state()
     if(COMPILER_SUPPORTS_SSE4_1)
       set(HAVE_SSE4_1 TRUE)
@@ -763,14 +769,14 @@ if(SDL_ASSEMBLY)
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -msse4.2")
     endif()
-    check_c_source_compiles("
+    check_x86_source_compiles([==[
       #include <nmmintrin.h>
       __m128i bitmask;
       char data[16];
       int main(int argc, char **argv) {
         bitmask = _mm_cmpgt_epi64(_mm_set1_epi64x(0), _mm_loadu_si128((void*)data));
         return 0;
-      }" COMPILER_SUPPORTS_SSE4_2)
+      }]==] COMPILER_SUPPORTS_SSE4_2)
     cmake_pop_check_state()
     if(COMPILER_SUPPORTS_SSE4_2)
       set(HAVE_SSE4_2 TRUE)
@@ -781,7 +787,7 @@ if(SDL_ASSEMBLY)
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -mavx")
     endif()
-    check_c_source_compiles("
+    check_x86_source_compiles([==[
       #include <immintrin.h>
       void floats_add(float *dest, float *a, float *b, unsigned size) {
         for (; size >= 8; size -= 8, dest += 8, a += 8, b += 8) {
@@ -791,7 +797,7 @@ if(SDL_ASSEMBLY)
       int main(int argc, char **argv) {
         floats_add((float*)0, (float*)0, (float*)0, 0);
         return 0;
-      }" COMPILER_SUPPORTS_AVX)
+      }]==] COMPILER_SUPPORTS_AVX)
     cmake_pop_check_state()
     if(COMPILER_SUPPORTS_AVX)
       set(HAVE_AVX TRUE)
@@ -802,7 +808,7 @@ if(SDL_ASSEMBLY)
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -mavx2")
     endif()
-    check_c_source_compiles("
+    check_x86_source_compiles([==[
       #include <immintrin.h>
       void ints_add(int *dest, int *a, int *b, unsigned size) {
         for (; size >= 8; size -= 8, dest += 8, a += 8, b += 8) {
@@ -812,7 +818,7 @@ if(SDL_ASSEMBLY)
       int main(int argc, char **argv) {
         ints_add((int*)0, (int*)0, (int*)0, 0);
         return 0;
-      }" COMPILER_SUPPORTS_AVX2)
+      }]==] COMPILER_SUPPORTS_AVX2)
     cmake_pop_check_state()
     if(COMPILER_SUPPORTS_AVX2)
       set(HAVE_AVX2 TRUE)
@@ -823,7 +829,7 @@ if(SDL_ASSEMBLY)
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -mavx512f")
     endif()
-    check_c_source_compiles("
+    check_x86_source_compiles([==[
       #include <immintrin.h>
       void floats_add(float *dest, float *a, float *b, unsigned size) {
         for (; size >= 16; size -= 16, dest += 16, a += 16, b += 16) {
@@ -833,7 +839,7 @@ if(SDL_ASSEMBLY)
       int main(int argc, char **argv) {
         floats_add((float*)0, (float*)0, (float*)0, 0);
         return 0;
-      }" COMPILER_SUPPORTS_AVX512F)
+      }]==] COMPILER_SUPPORTS_AVX512F)
     cmake_pop_check_state()
     if(COMPILER_SUPPORTS_AVX512F)
       set(HAVE_AVX512F TRUE)
@@ -841,18 +847,17 @@ if(SDL_ASSEMBLY)
   endif()
 
   if(SDL_ARMNEON)
-    check_c_source_compiles("
-        #include <arm_neon.h>
-        void floats_add(float *dest, float *a, float *b, unsigned size) {
-          for (; size >= 4; size -= 4, dest += 4, a += 4, b += 4) {
-            vst1q_f32(dest, vaddq_f32(vld1q_f32(a), vld1q_f32(b)));
-          }
+    check_arm_source_compiles([==[
+      #include <arm_neon.h>
+      void floats_add(float *dest, float *a, float *b, unsigned size) {
+        for (; size >= 4; size -= 4, dest += 4, a += 4, b += 4) {
+          vst1q_f32(dest, vaddq_f32(vld1q_f32(a), vld1q_f32(b)));
         }
-        int main(int argc, char *argv[]) {
-          floats_add((float*)0, (float*)0, (float*)0, 0);
-          return 0;
-         }" COMPILER_SUPPORTS_ARMNEON)
-
+      }
+      int main(int argc, char *argv[]) {
+        floats_add((float*)0, (float*)0, (float*)0, 0);
+        return 0;
+      }]==] COMPILER_SUPPORTS_ARMNEON)
     if(COMPILER_SUPPORTS_ARMNEON)
       set(HAVE_ARMNEON TRUE)
     endif()

cmake/sdlcompilers.cmake

@@ -160,3 +160,63 @@ function(SDL_AddCommonCompilerFlags TARGET)
     endif()
   endif()
 endfunction()
+
+function(check_x86_source_compiles BODY VAR)
+  if(ARGN)
+    message(FATAL_ERROR "Unknown arguments: ${ARGN}")
+  endif()
+  if(APPLE_MULTIARCH AND (SDL_CPU_X86 OR SDL_CPU_X64))
+    set(test_conditional 1)
+  else()
+    set(test_conditional 0)
+  endif()
+  check_c_source_compiles("
+    #if ${test_conditional}
+    # if defined(__i386__) || defined(__x86_64__)
+    #  define test_enabled 1
+    # else
+    #  define test_enabled 0 /* feign success in Apple multi-arch configs */
+    # endif
+    #else                    /* test normally */
+    # define test_enabled 1
+    #endif
+    #if test_enabled
+    ${BODY}
+    #else
+    int main(int argc, char *argv[]) {
+      (void)argc;
+      (void)argv;
+      return 0;
+    }
+    #endif" ${VAR})
+endfunction()
+
+function(check_arm_source_compiles BODY VAR)
+  if(ARGN)
+    message(FATAL_ERROR "Unknown arguments: ${ARGN}")
+  endif()
+  if(APPLE_MULTIARCH AND (SDL_CPU_ARM32 OR SDL_CPU_ARM64))
+    set(test_conditional 1)
+  else()
+    set(test_conditional 0)
+  endif()
+  check_c_source_compiles("
+    #if ${test_conditional}
+    # if defined(__arm__) || defined(__aarch64__)
+    #  define test_enabled 1
+    # else
+    #  define test_enabled 0 /* feign success in Apple multi-arch configs */
+    # endif
+    #else                    /* test normally */
+    # define test_enabled 1
+    #endif
+    #if test_enabled
+    ${BODY}
+    #else
+    int main(int argc, char *argv[]) {
+      (void)argc;
+      (void)argv;
+      return 0;
+    }
+    #endif" ${VAR})
+endfunction()

cmake/sdlcpu.cmake

@@ -4,15 +4,15 @@ function(SDL_DetectTargetCPUArchitectures DETECTED_ARCHS)
 
   if(APPLE AND CMAKE_OSX_ARCHITECTURES)
     foreach(known_arch IN LISTS known_archs)
-      set(SDL_CPU_${known_arch} "0")
+      set(SDL_CPU_${known_arch} "0" PARENT_SCOPE)
     endforeach()
     set(detected_archs)
     foreach(osx_arch IN LISTS CMAKE_OSX_ARCHITECTURES)
       if(osx_arch STREQUAL "x86_64")
-        set(SDL_CPU_X64 "1")
+        set(SDL_CPU_X64 "1" PARENT_SCOPE)
         list(APPEND detected_archs "X64")
       elseif(osx_arch STREQUAL "arm64")
-        set(SDL_CPU_ARM64 "1")
+        set(SDL_CPU_ARM64 "1" PARENT_SCOPE)
         list(APPEND detected_archs "ARM64")
       endif()
     endforeach()