fix ARM build failing for SDL2

Author: silbinarywolf

.github/workflows/ci.yml

@@ -36,21 +36,21 @@ jobs:
     - name: Setup Android SDK
       uses: android-actions/setup-android@v3
       with:
-        packages: 'tools platform-tools platforms;android-35 build-tools;35.0.0 ndk;27.0.12077973'
+        packages: 'tools platform-tools platforms;android-35 build-tools;35.0.0 ndk;29.0.13113456'
 
-    - name: Setup Zig 0.13.0
+    - name: Setup Zig 0.14.0
       # note(jae): 2024-09-15
       # Uses download mirror first as preferred by Zig Foundation
       # see: https://ziglang.org/news/migrate-to-self-hosting/
       uses: mlugg/setup-zig@v1
       with:
-        version: "0.13.0"
+        version: "0.14.0"
 
-    - name: Build Minimal Example (Zig 0.13.0)
+    - name: Build Minimal Example (Zig Nightly)
       run: zig build -Dandroid=true --verbose
       working-directory: examples/minimal
 
-    - name: Build SDL2 Example (Zig 0.13.0)
+    - name: Build SDL2 Example (Zig Nightly)
       run: zig build -Dandroid=true --verbose
       working-directory: examples/sdl2
 
@@ -64,11 +64,5 @@ jobs:
       working-directory: examples/minimal
 
     - name: Build SDL2 Example (Zig Nightly)
-      # "zig build -Dandroid=true" fails for 0.14.0-dev.1632
-      #
-      # android/sdk/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include/android/hardware_buffer.h:322:42:
-      # error: expression is not an integral constant expression
-      #
-      # See: https://github.com/silbinarywolf/zig-android-sdk/actions/runs/10979711793/job/30484520174?pr=5#step:10:30
-      run: zig build -Dtarget=x86_64-linux-android --verbose
+      run: zig build -Dandroid=true --verbose
       working-directory: examples/sdl2

examples/minimal/build.zig

@@ -22,7 +22,7 @@ pub fn build(b: *std.Build) void {
         const android_tools = android.Tools.create(b, .{
             .api_level = .android15,
             .build_tools_version = "35.0.0",
-            .ndk_version = "27.0.12077973",
+            .ndk_version = "29.0.13113456",
         });
         const apk = android.APK.create(b, android_tools);
 

examples/sdl2/build.zig

@@ -21,7 +21,16 @@ pub fn build(b: *std.Build) void {
         const android_tools = android.Tools.create(b, .{
             .api_level = .android15,
             .build_tools_version = "35.0.0",
-            .ndk_version = "27.0.12077973",
+            .ndk_version = "29.0.13113456",
+            // NOTE(jae): 2025-03-09
+            // Previously this example used 'ndk' "27.0.12077973".
+            //
+            // However that has issues with the latest SDL2 version when including 'hardware_buffer.h'
+            // for 32-bit builds.
+            //
+            // - AHARDWAREBUFFER_USAGE_FRONT_BUFFER = 1UL << 32
+            //  - ndk/27.0.12077973/toolchains/llvm/prebuilt/{OS}-x86_64/sysroot/usr/include/android/hardware_buffer.h:322:42:
+            //  - error: expression is not an integral constant expression
         });
         const apk = android.APK.create(b, android_tools);
 

src/androidbuild/androidbuild.zig

@@ -151,15 +151,11 @@ const supported_android_targets = [_]AndroidTargetQuery{
         .cpu_arch = .aarch64,
         .cpu_features_add = Target.aarch64.featureSet(&.{.v8a}),
     },
-    // TODO(jae): 2024-09-08
-    // This doesn't work for compiling C code like SDL2 or OpenXR due to "__ARM_ARCH" not being "7"
-    // or similar. I might be messing something up here but not sure.
-    //
-    // TODO(jae): 2025-03-08
-    // Look into fixing: src/cpuinfo/SDL_cpuinfo.c:93:10: error: 'cpu-features.h' file not found
-    // .{
-    //     // arm-linux-androideabi
-    //     .cpu_arch = .arm,
-    //     .cpu_features_add = Target.arm.featureSet(&.{.v7a}),
-    // },
+    // NOTE(jae): 2024-09-08
+    // 'arm-linux-androideabi' previously didn't work with Zig 0.13.0 for compiling C code like SDL2 or OpenXR due to "__ARM_ARCH" not being "7"
+    .{
+        // arm-linux-androideabi
+        .cpu_arch = .arm,
+        .cpu_features_add = Target.arm.featureSet(&.{.v7a}),
+    },
 };

src/androidbuild/apk.zig

@@ -129,6 +129,19 @@ pub const APK = struct {
         // - "java.lang.UnsatisfiedLinkError: dlopen failed: TLS symbol "_ZZN8gwp_asan15getThreadLocalsEvE6Locals" in dlopened"
         const android_api_version: u32 = @intFromEnum(apk.tools.api_level);
 
+        // NOTE(jae): 2025-03-09
+        // Resolve issue where building SDL2 gets the following error for 'arm-linux-androideabi'
+        // SDL2-2.32.2/src/cpuinfo/SDL_cpuinfo.c:93:10: error: 'cpu-features.h' file not found
+        //
+        // This include is specifically needed for: #if defined(__ANDROID__) && defined(__arm__) && !defined(HAVE_GETAUXVAL)
+        //
+        // ie. $ANDROID_HOME/ndk/{ndk_version}/sources/android/cpufeatures
+        if (module.resolved_target) |resolved_target| {
+            if (resolved_target.result.cpu.arch == .arm) {
+                module.addIncludePath(.{ .cwd_relative = b.fmt("{s}/ndk/{s}/sources/android/cpufeatures", .{ apk.tools.android_sdk_path, apk.tools.ndk_version }) });
+            }
+        }
+
         // ie. $ANDROID_HOME/ndk/{ndk_version}/toolchains/llvm/prebuilt/{host_os_and_arch}/sysroot ++ usr/lib/aarch64-linux-android/35
         module.addLibraryPath(.{ .cwd_relative = b.fmt("{s}/usr/lib/{s}/{d}", .{ android_ndk_sysroot, system_target, android_api_version }) });
         // ie. $ANDROID_HOME/ndk/{ndk_version}/toolchains/llvm/prebuilt/{host_os_and_arch}/sysroot ++ /usr/lib/aarch64-linux-android