Simplify browser builds and SPIR-V testing

.github/workflows/build.yml

@@ -14,6 +14,9 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
+      - uses: actions/setup-python@v7
+        with:
+          python-version: "3.13"
       - if: runner.os == 'Linux'
         run: |
           sudo apt-get update

CHANGELOG.md

@@ -35,3 +35,4 @@ browser target.
 - The legacy raw WebGPU C API implementation, manual resource pools, custom
   half implementation, Haskell binding, obsolete build files, and abandoned
   experimental targets.
+- The Closure compiler and Java dependency from browser builds.

CMakeLists.txt

@@ -30,10 +30,7 @@ if(EMSCRIPTEN)
   endif()
   target_compile_options(gpucpp INTERFACE "${EMDAWN_PORT}" "-fwasm-exceptions")
   target_link_options(gpucpp INTERFACE "${EMDAWN_PORT}" "-fwasm-exceptions"
-                                           "-sJSPI=1" "--closure=1")
-  if(CMAKE_HOST_APPLE)
-    target_link_options(gpucpp INTERFACE "--closure-args=--platform=java")
-  endif()
+                                           "-sJSPI=1")
 else()
 
 set(GPUCPP_DAWN_ROOT "${CMAKE_CURRENT_SOURCE_DIR}/third_party/dawn" CACHE PATH

DEV.md

@@ -11,8 +11,7 @@ The same file pins the emsdk revision and Emscripten version recorded in
 Dawn's DEPS. `tools/build_emdawn.sh` builds `emdawnwebgpu_pkg` from that exact
 Dawn source and stages its local Emscripten port under
 `third_party/emdawnwebgpu/`. The sibling `../emsdk` clone and staged package are
-not committed. Closure is required by Emdawn release links and uses OpenJDK on
-macOS ARM.
+not committed.
 
 The top-level build fetches the tagged pybind11 release declared in
 `CMakeLists.txt`; consumers using only the C++ target do not fetch or build it.
@@ -69,9 +68,9 @@ local release path.
 `./test --web` cross-compiles the same public core and Embind API against
 Emdawnwebgpu, opens the result with `emrun`, and checks rejected invalid WGSL,
 context reuse, typed-array upload, dispatch, and readback in Chrome. The
-release build uses Closure, Wasm exceptions, and JSPI. CI uses
-`./test --build-web` to compile the same artifacts without requiring a browser
-GPU; the complete story remains the local runtime contract.
+release build uses Wasm exceptions and JSPI. CI uses `./test --build-web` to
+compile the same artifacts without requiring a browser GPU; the complete story
+remains the local runtime contract.
 
 ## Architecture
 

README.md

@@ -27,11 +27,10 @@ Dawn library, and stages its headers, library, and `spirv-as` under
 and build trees under `third_party/local/dawn/` directly.
 
 Browser builds require Chrome with WebGPU and JSPI, plus a sibling `../emsdk`
-clone. On macOS they also require OpenJDK for Closure:
+clone:
 
 ```bash
 git clone --depth 1 https://github.com/emscripten-core/emsdk.git ../emsdk
-brew install openjdk
 ./test --rebuild-web
 ```
 
@@ -132,6 +131,23 @@ target_link_libraries(my_program PRIVATE gpucpp)
 See [DEV.md](DEV.md) for the dependency layout and update process, and
 [CHANGELOG.md](CHANGELOG.md) for release notes.
 
+Browser consumers can supply their own Embind surface while inheriting the
+Emdawnwebgpu, Wasm-exception, and JSPI settings from `gpucpp`:
+
+```cmake
+add_subdirectory(path/to/gpu.cpp EXCLUDE_FROM_ALL)
+add_executable(my_web_app app.cpp)
+set_target_properties(my_web_app PROPERTIES SUFFIX ".js")
+target_link_libraries(my_web_app PRIVATE gpucpp)
+target_link_options(my_web_app PRIVATE "--bind" "--no-entry"
+  "-sMODULARIZE=1" "-sEXPORT_NAME=createModule" "-sENVIRONMENT=web"
+  "-sALLOW_MEMORY_GROWTH=1")
+```
+
+The Embind functions that call `createContext()`, `wait()`, or browser-facing
+helpers containing them must use `emscripten::async()` so JSPI can suspend the
+Wasm stack.
+
 ## Python
 
 Install the self-contained macOS ARM64 wheel from PyPI with `pip install

test

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
+external_spirv=
 if [[ ${1:-} == --web || ${1:-} == --build-web || \
       ${1:-} == --rebuild-web ]]; then
   if [[ ${1:-} == --rebuild-web || \
@@ -9,15 +10,6 @@ if [[ ${1:-} == --web || ${1:-} == --build-web || \
   fi
   export EMSDK_QUIET=1
   source "${GPUCPP_EMSDK_ROOT:-../emsdk}/emsdk_env.sh" >/dev/null
-  if [[ $(uname -s) == Darwin ]]; then
-    if [[ -x /opt/homebrew/opt/openjdk/bin/java ]]; then
-      export PATH="/opt/homebrew/opt/openjdk/bin:$PATH"
-    fi
-    if ! java -version >/dev/null 2>&1; then
-      echo "Closure requires Java on macOS; install it with brew install openjdk" >&2
-      exit 1
-    fi
-  fi
   emcmake cmake -S . -B build-web -G Ninja -DCMAKE_BUILD_TYPE=Release
   cmake --build build-web --target gpu_cpp_web web_binding_test
   if [[ ${1:-} != --build-web ]]; then
@@ -26,8 +18,10 @@ if [[ ${1:-} == --web || ${1:-} == --build-web || \
   exit
 elif [[ ${1:-} == --rebuild-dawn ]]; then
   tools/build_dawn.sh
+elif [[ ${1:-} == --spirv && $# -eq 2 ]]; then
+  external_spirv=$2
 elif [[ $# -ne 0 ]]; then
-  echo "usage: ./test [--rebuild-dawn|--web|--build-web|--rebuild-web]" >&2
+  echo "usage: ./test [--rebuild-dawn|--web|--build-web|--rebuild-web|--spirv FILE]" >&2
   exit 2
 elif [[ ! -f third_party/dawn/include/dawn/webgpu_cpp.h &&
         ! -f third_party/local/dawn/build-latest/gen/include/dawn/webgpu_cpp.h ]]; then
@@ -37,3 +31,6 @@ fi
 cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
 cmake --build build
 ctest --test-dir build --output-on-failure
+if [[ -n $external_spirv ]]; then
+  build/gpu_test build/write42.spv "$external_spirv"
+fi

tests/gpu_test.cpp

@@ -51,7 +51,8 @@ static void expect(const std::vector<T> &actual,
 }
 
 int main(int argc, char **argv) {
-  if (argc != 2) throw std::runtime_error("expected assembled SPIR-V path");
+  if (argc != 2 && argc != 3)
+    throw std::runtime_error("expected assembled SPIR-V path");
 
   // Ordinary WGSL covers upload, explicit binding access, dispatch, and readback.
   auto context = createContext();
@@ -98,5 +99,19 @@ int main(int argc, char **argv) {
   wait(spirvContext, answerDownloaded);
   expect(answer, std::vector<int32_t>{42}, "SPIR-V compute");
 
+  if (argc == 3) {
+    std::vector<int32_t> externalAnswer(1);
+    auto externalOutput = createTensor(spirvContext, {1}, ki32);
+    auto external = createKernel(
+        spirvContext, SPIRV{readSPIRV(argv[2]), "external SPIR-V", "main"},
+        Bindings{readWrite(externalOutput)});
+    auto externalDispatched = dispatchKernel(spirvContext, external);
+    wait(spirvContext, externalDispatched);
+    auto externalDownloaded =
+        toCPU(spirvContext, externalOutput, externalAnswer);
+    wait(spirvContext, externalDownloaded);
+    expect(externalAnswer, std::vector<int32_t>{42}, "external SPIR-V compute");
+  }
+
   std::cout << "WGSL, f16, and SPIR-V compute stories passed\n";
 }