Make libink build compatible with Mac on arm64

PiperOrigin-RevId: 900244650

Author: sfreilich

ink/geometry/internal/jni/partitioned_mesh_jni.cc

@@ -36,8 +36,13 @@ JNI_METHOD(geometry, PartitionedMeshNative, jlongArray,
   PartitionedMeshNative_fillRenderGroupMeshPointers(native_pointer, group_index,
                                                     meshes_ptrs.data());
   jlongArray mesh_pointers = env->NewLongArray(group_mesh_count);
+  // Both `jlong` and `int64_t` are required to be 64-bit integers which JNI and
+  // Kotlin-cinterop respectively both map to Kotlin `Long`. However, on MacOS
+  // they represent two distinct (though equivalent) types, `jlong` is `long`
+  // but `int64_t` is `long long`.
+  static_assert(sizeof(jlong) == sizeof(int64_t));
   env->SetLongArrayRegion(mesh_pointers, 0, group_mesh_count,
-                          meshes_ptrs.data());
+                          reinterpret_cast<jlong*>(meshes_ptrs.data()));
   return mesh_pointers;
 }
 

ink/jni/BUILD.bazel

@@ -21,17 +21,24 @@ package(
 
 cc_binary(
     name = "libink.so",
-    additional_linker_inputs = ["jni.lds"],
-    features = ["-legacy_whole_archive"],
-    linkopts = [
-        # Use a linker script to limit exported symbols to JNI functions.
-        "-Wl,--version-script=$(location :jni.lds)",
+    additional_linker_inputs = [
+        "exported_symbols.txt",
+        "jni.lds",
     ],
+    features = ["-legacy_whole_archive"],
+    linkopts = select({
+        "@platforms//os:macos": [
+            "-Wl,-exported_symbols_list,$(location :exported_symbols.txt)",
+        ],
+        "//conditions:default": [
+            # Use a linker script to limit exported symbols to JNI functions.
+            "-Wl,--version-script=$(location :jni.lds)",
+        ],
+    }),
     linkshared = 1,
     linkstatic = 1,
     deps = [
         ":android_all_jni",
-        ":jni.lds",
     ],
 )
 

ink/jni/exported_symbols.txt

@@ -0,0 +1,2 @@
+Java_*;
+JNI_*;