Bazel: Migrate to bzlmod (#1530)

This migrates the bazel integration to the new Bazel dependency system
"bzlmod". bzlmod is becoming mandatory this year (see second sentence
here: https://bazel.build/external/migration).

This is a backwards incompatible migration, directly removing the old
WORKSPACE based approach. Users will have to change how they depend on
bzlmod, however I assume pretty much every user will be happy about it,
because they are forced to use bzlmod anyway or add extra flags to
continue to build with newer Bazel versions. Given that users normally
depend on specific git commits in the old system, they won't be hit with
this until they decide to upgrade emsdk.

The basic principle here is simple: I took everything that WORKSPACE did
and searched an alternative in bzlmod. Some interesting bits:

- We have less worries about multiple versions and people depending on
emscripten multiple times in different ways. This is resolved by the new
system: Bazel first iterates through the MODULE.bazel files recursively,
then finds the minimum version needed for each module and then executes
the module extensions that define repos exactly once at that version. So
no more ifs needed to detect multiple inclusions.
- A bunch of nodejs stuff moves to MODULE.bazel, because that is how the
nodejs module works now. As their module extension gets executed only
once you need to declare everything that you could need before that in
the MODULE.bazel file. A side effect of that is that we have to make a
fake repository when emscripten doesn't have an arm64 binary for linux,
because we can't actually figure that out in MODULE.bazel, so we have to
declare that it always exists and then create one in all cases.

There is a bunch of autoformatter changes in here as well, I could try
to revert them if you prefer.

Closes #1509

.circleci/config.yml

@@ -38,6 +38,39 @@ commands:
           command: |
             source emsdk_env.sh
             test/test.py
+  test-bazel-linux:
+    steps:
+      - checkout
+      - run:
+          name: install bazelisk
+          command: |
+            wget https://github.com/bazelbuild/bazelisk/releases/download/v1.25.0/bazelisk-linux-amd64
+            chmod +x bazelisk-linux-amd64
+            mv bazelisk-linux-amd64 /usr/local/bin/bazel
+      - run: test/test_bazel.sh
+  test-bazel-mac:
+    steps:
+      - checkout
+      - run:
+          name: install bazelisk
+          command: |
+            brew install bazelisk
+      - run: test/test_bazel_mac.sh
+  test-bazel-windows:
+    steps:
+      - checkout
+      - run:
+          name: Download Bazelisk
+          shell: powershell.exe
+          command: |
+            $ProgressPreference = "SilentlyContinue"
+            Invoke-WebRequest -Uri https://github.com/bazelbuild/bazelisk/releases/download/v1.10.1/bazelisk-windows-amd64.exe -OutFile ( New-Item -Path "temp\bazel\bazel.exe" -Force )
+      - run:
+          name: Run Tests
+          shell: powershell.exe
+          command: |
+            $env:Path += ";C:\Python27amd64;$pwd\temp\bazel"
+            .\test\test_bazel.ps1
 
 jobs:
   flake8:
@@ -223,60 +256,52 @@ jobs:
             docker login -u "$DOCKER_USER" -p "$DOCKER_PASS"
             make -C ./docker version=${CIRCLE_TAG} alias=${CIRCLE_TAG}-arm64 only_alias=true push
 
-  test-bazel-linux:
+  test-bazel7-linux:
+    executor: ubuntu
+    environment:
+      USE_BAZEL_VERSION: "7.x"
+    steps:
+      - test-bazel-linux
+
+  test-bazel-latest-linux:
     executor: ubuntu
     steps:
-      - checkout
+      - test-bazel-linux
-      - run: apt-get install -q -y curl gnupg
-      - run: curl -fsSL https://bazel.build/bazel-release.pub.gpg | gpg --dearmor > bazel.gpg
-      - run: mv bazel.gpg /etc/apt/trusted.gpg.d/
-      - run: echo "deb [arch=amd64] https://storage.googleapis.com/bazel-apt stable jdk1.8" | tee /etc/apt/sources.list.d/bazel.list
-      - run:
-          name: install pip
-          command: |
-            apt-get update -q
-            apt-get install -q -y python3-pip
-      - run: pip3 install absl-py
-      - run:
-          name: install bazel
-          command: |
-            apt-get install -q -y bazel-7.4.1
-      - run: test/test_bazel.sh
 
-  test-bazel-mac-arm64:
+  test-bazel7-mac-arm64:
     executor: mac_arm64
     environment:
-      USE_BAZEL_VERSION: "7.4.1"
+      USE_BAZEL_VERSION: "7.x"
     steps:
-      - checkout
+      - test-bazel-mac
-      - run:
-          name: install bazelisk
-          command: |
-            brew install bazelisk
-      - run: test/test_bazel_mac.sh
 
-  test-bazel-windows:
+  test-bazel-latest-mac-arm64:
+    executor: mac_arm64
+    steps:
+      - test-bazel-mac
+
+  test-bazel7-windows:
     executor:
       name: win/server-2019
       shell: powershell.exe -ExecutionPolicy Bypass
     environment:
       PYTHONUNBUFFERED: "1"
       EMSDK_NOTTY: "1"
-      USE_BAZEL_VERSION: "5.4.0"
+      # For some reason version resolution with "7.x" does not work on Windows,
+      # so we have to specify a full version.
+      USE_BAZEL_VERSION: "7.6.1"
     steps:
-      - checkout
+      - test-bazel-windows
-      - run:
+
-          name: Download Bazelisk
+  test-bazel-latest-windows:
-          shell: powershell.exe
+    executor:
-          command: |
+      name: win/server-2019
-            $ProgressPreference = "SilentlyContinue"
+      shell: powershell.exe -ExecutionPolicy Bypass
-            Invoke-WebRequest -Uri https://github.com/bazelbuild/bazelisk/releases/download/v1.10.1/bazelisk-windows-amd64.exe -OutFile ( New-Item -Path "temp\bazel\bazel.exe" -Force )
+    environment:
-      - run:
+      PYTHONUNBUFFERED: "1"
-          name: Run Tests
+      EMSDK_NOTTY: "1"
-          shell: powershell.exe
+    steps:
-          command: |
+      - test-bazel-windows
-            $env:Path += ";C:\Python27amd64;$pwd\temp\bazel"
-            .\test\test_bazel.ps1
 
 workflows:
   flake8:
@@ -309,12 +334,21 @@ workflows:
               ignore: /.*/
             tags:
               only: /.*/
-  test-bazel-linux:
+  test-bazel7-linux:
     jobs:
-      - test-bazel-linux
+      - test-bazel7-linux
-  test-bazel-mac-arm64:
+  test-bazel-latest-linux:
     jobs:
-      - test-bazel-mac-arm64
+      - test-bazel-latest-linux
-  test-bazel-windows:
+  test-bazel7-mac-arm64:
     jobs:
-      - test-bazel-windows
+      - test-bazel7-mac-arm64
+  test-bazel-latest-mac-arm64:
+    jobs:
+      - test-bazel-latest-mac-arm64
+  test-bazel7-windows:
+    jobs:
+      - test-bazel7-windows
+  test-bazel-latest-windows:
+    jobs:
+      - test-bazel-latest-windows

bazel/BUILD

@@ -1,83 +1,7 @@
 package(default_visibility = ["//visibility:public"])
 
-config_setting(
-    name = "linux",
-    constraint_values = [
-        "@platforms//os:linux",
-        "@platforms//cpu:x86_64",
-    ],
-)
-
-config_setting(
-    name = "linux_arm64",
-    constraint_values = [
-        "@platforms//os:linux",
-        "@platforms//cpu:arm64",
-    ],
-)
-
-config_setting(
-    name = "macos",
-    constraint_values = [
-        "@platforms//os:macos",
-        "@platforms//cpu:x86_64",
-    ],
-)
-
-config_setting(
-    name = "macos_arm64",
-    constraint_values = [
-        "@platforms//os:macos",
-        "@platforms//cpu:arm64",
-    ],
-)
-
-config_setting(
-    name = "windows",
-    constraint_values = [
-        "@platforms//os:windows",
-        "@platforms//cpu:x86_64",
-    ],
-)
-
 filegroup(name = "empty")
 
-alias(
-    name = "compiler_files",
-    actual = select({
-        ":linux": "@emscripten_bin_linux//:compiler_files",
-        ":linux_arm64": "@emscripten_bin_linux_arm64//:compiler_files",
-        ":macos": "@emscripten_bin_mac//:compiler_files",
-        ":macos_arm64": "@emscripten_bin_mac_arm64//:compiler_files",
-        ":windows": "@emscripten_bin_win//:compiler_files",
-        "//conditions:default": ":empty",
-    }),
-)
-
-alias(
-    name = "linker_files",
-    actual = select({
-        ":linux": "@emscripten_bin_linux//:linker_files",
-        ":linux_arm64": "@emscripten_bin_linux_arm64//:linker_files",
-        ":macos": "@emscripten_bin_mac//:linker_files",
-        ":macos_arm64": "@emscripten_bin_mac_arm64//:linker_files",
-        ":windows": "@emscripten_bin_win//:linker_files",
-        "//conditions:default": ":empty",
-    }),
-)
-
-alias(
-    name = "ar_files",
-    actual = select({
-        ":linux": "@emscripten_bin_linux//:ar_files",
-        ":linux_arm64": "@emscripten_bin_linux_arm64//:ar_files",
-        ":macos": "@emscripten_bin_mac//:ar_files",
-        ":macos_arm64": "@emscripten_bin_mac_arm64//:ar_files",
-        ":windows": "@emscripten_bin_win//:ar_files",
-        "//conditions:default": ":empty",
-    }),
-)
-
 platform(
     name = "platform_wasm",
     constraint_values = [

bazel/MODULE.bazel

@@ -1 +1,79 @@
-bazel_dep(name = "platforms", version = "0.0.9")
+module(
+    name = "emsdk",
+    version = "4.0.6",
+)
+
+bazel_dep(name = "platforms", version = "0.0.11")
+bazel_dep(name = "bazel_skylib", version = "1.7.1")
+bazel_dep(name = "aspect_rules_js", version = "1.42.0")
+bazel_dep(name = "rules_nodejs", version = "6.3.2")
+bazel_dep(name = "rules_cc", version = "0.1.1")
+bazel_dep(name = "rules_python", version = "1.3.0")
+
+python = use_extension("@rules_python//python/extensions:python.bzl", "python")
+python.toolchain(
+    python_version = "3.13",
+)
+
+node = use_extension("@rules_nodejs//nodejs:extensions.bzl", "node")
+node.toolchain(node_version = "20.18.0")
+use_repo(node, "nodejs")
+
+emscripten_deps = use_extension(
+    "//:emscripten_deps.bzl",
+    "emscripten_deps",
+)
+use_repo(emscripten_deps, "emscripten_bin_linux")
+use_repo(emscripten_deps, "emscripten_bin_linux_arm64")
+use_repo(emscripten_deps, "emscripten_bin_mac")
+use_repo(emscripten_deps, "emscripten_bin_mac_arm64")
+use_repo(emscripten_deps, "emscripten_bin_win")
+
+npm = use_extension(
+    "@aspect_rules_js//npm:extensions.bzl",
+    "npm",
+)
+npm.npm_translate_lock(
+    name = "emscripten_npm_linux",
+    data = ["@emscripten_bin_linux//:emscripten/package.json"],
+    npm_package_lock = "@emscripten_bin_linux//:emscripten/package-lock.json",
+)
+npm.npm_translate_lock(
+    name = "emscripten_npm_linux_arm64",
+    data = ["@emscripten_bin_linux_arm64//:emscripten/package.json"],
+    npm_package_lock = "@emscripten_bin_linux_arm64//:emscripten/package-lock.json",
+)
+npm.npm_translate_lock(
+    name = "emscripten_npm_mac",
+    data = ["@emscripten_bin_mac//:emscripten/package.json"],
+    npm_package_lock = "@emscripten_bin_mac//:emscripten/package-lock.json",
+)
+npm.npm_translate_lock(
+    name = "emscripten_npm_mac_arm64",
+    data = ["@emscripten_bin_mac_arm64//:emscripten/package.json"],
+    npm_package_lock = "@emscripten_bin_mac_arm64//:emscripten/package-lock.json",
+)
+npm.npm_translate_lock(
+    name = "emscripten_npm_win",
+    data = ["@emscripten_bin_win//:emscripten/package.json"],
+    npm_package_lock = "@emscripten_bin_win//:emscripten/package-lock.json",
+)
+use_repo(
+    npm,
+    "emscripten_npm_linux",
+    "emscripten_npm_linux_arm64",
+    "emscripten_npm_mac",
+    "emscripten_npm_mac_arm64",
+    "emscripten_npm_win",
+)
+
+emscripten_cache = use_extension("//:emscripten_cache.bzl", "emscripten_cache")
+use_repo(emscripten_cache, "emscripten_cache")
+
+register_toolchains(
+    "//emscripten_toolchain:cc-toolchain-wasm-emscripten_linux",
+    "//emscripten_toolchain:cc-toolchain-wasm-emscripten_linux_arm64",
+    "//emscripten_toolchain:cc-toolchain-wasm-emscripten_mac",
+    "//emscripten_toolchain:cc-toolchain-wasm-emscripten_mac_arm64",
+    "//emscripten_toolchain:cc-toolchain-wasm-emscripten_win",
+)

bazel/README.md

@@ -2,35 +2,29 @@
 
 ## Setup Instructions
 
-In `WORKSPACE` file, put:
+Support for depending on emsdk with a WORKSPACE file was removed and last available in [emsdk version 4.0.6](https://github.com/emscripten-core/emsdk/tree/24fc909c0da13ef641d5ae75e89b5a97f25e37aa). Now we only support inclusion as a bzlmod module.
+
+In your `MODULE.bazel` file, put:
 ```starlark
-load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
+emsdk_version = "4.0.6"
-git_repository(
+bazel_dep(name = "emsdk", version = emsdk_version)
-    name = "emsdk",
+git_override(
+    module_name = "emsdk",
     remote = "https://github.com/emscripten-core/emsdk.git",
-    tag = "3.1.64",
     strip_prefix = "bazel",
+    tag = emsdk_version,
 )
-
-load("@emsdk//:deps.bzl", emsdk_deps = "deps")
-emsdk_deps()
-
-load("@emsdk//:emscripten_deps.bzl", emsdk_emscripten_deps = "emscripten_deps")
-emsdk_emscripten_deps(emscripten_version = "3.1.64")
-
-load("@emsdk//:toolchains.bzl", "register_emscripten_toolchains")
-register_emscripten_toolchains()
-```
-The `tag` and `emscripten_version` parameters correspond to the git revision of
-[emsdk 3.1.64](https://github.com/emscripten-core/emsdk/releases/tag/3.1.64). To get access to
-newer versions, you'll need to update those. To make use of older versions, change the
-parameter of `git_repository` and `emsdk_emscripten_deps()`. Supported versions are listed in `revisions.bzl`
-
-Bazel 7+ additionally requires `platforms` dependencies in the `MODULE.bazel` file.
-```starlark
-bazel_dep(name = "platforms", version = "0.0.9")
 ```
 
+You can use a different version of this SDK by changing it in your `MODULE.bazel` file. The Emscripten version is by default the same as the SDK version, but you can use a different one as well by adding to your `MODULE.bazel`:
+
+```
+emscripten_deps = use_extension(
+    "@emsdk//:emscripten_deps.bzl",
+    "emscripten_deps",
+)
+emscripten_deps.config(version = "4.0.1")
+```
 
 ## Building
 
@@ -68,28 +62,29 @@ is the preferred way, since it also unpacks the resulting tarball.
 
 The Emscripten cache shipped by default does not include LTO, 64-bit or PIC
 builds of the system libraries and ports. If you wish to use these features you
-will need to declare the cache when you register the toolchain as follows. Note
+will need to declare the cache in your `MODULE.bazel` as follows. Note
 that the configuration consists of the same flags that can be passed to
-embuilder. If `targets` is not provided, all system libraries and ports will be
+embuilder. If `targets` is not set, all system libraries and ports will be
 built, i.e., the `ALL` option to embuilder.
 
 ```starlark
-load("@emsdk//:toolchains.bzl", "register_emscripten_toolchains")
+emscripten_cache = use_extension(
-register_emscripten_toolchains(cache = {
+    "@emsdk//:emscripten_cache.bzl",
-    "configuration": ["--lto"],
+    "emscripten_cache",
-    "targets": [
+)
-        "crtbegin",
+emscripten_cache.configuration(flags = ["--lto"])
-        "libprintf_long_double-debug",
+emscripten_cache.targets(targets = [
-        "libstubs-debug",
+    "crtbegin",
-        "libnoexit",
+    "libprintf_long_double-debug",
-        "libc-debug",
+    "libstubs-debug",
-        "libdlmalloc",
+    "libnoexit",
-        "libcompiler_rt",
+    "libc-debug",
-        "libc++-noexcept",
+    "libdlmalloc",
-        "libc++abi-debug-noexcept",
+    "libcompiler_rt",
-        "libsockets"
+    "libc++-noexcept",
-    ]
+    "libc++abi-debug-noexcept",
-})
+    "libsockets"
+])
 ```
 
 See `test_external/` for an example using [embind](https://emscripten.org/docs/porting/connecting_cpp_and_javascript/embind.html).

bazel/WORKSPACE

@@ -1,13 +0,0 @@
-workspace(name = "emsdk")
-
-load(":deps.bzl", "deps")
-
-deps()
-
-load(":emscripten_deps.bzl", "emscripten_deps")
-
-emscripten_deps()
-
-load(":toolchains.bzl", "register_emscripten_toolchains")
-
-register_emscripten_toolchains()

bazel/deps.bzl

@@ -1,52 +0,0 @@
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-load("@bazel_tools//tools/build_defs/repo:utils.bzl", "maybe")
-
-def deps():
-    maybe(
-        http_archive,
-        name = "platforms",
-        urls = [
-            "https://mirror.bazel.build/github.com/bazelbuild/platforms/releases/download/0.0.9/platforms-0.0.9.tar.gz",
-            "https://github.com/bazelbuild/platforms/releases/download/0.0.9/platforms-0.0.9.tar.gz",
-        ],
-        sha256 = "5eda539c841265031c2f82d8ae7a3a6490bd62176e0c038fc469eabf91f6149b",
-    )
-    maybe(
-        http_archive,
-        name = "bazel_skylib",
-        sha256 = "c6966ec828da198c5d9adbaa94c05e3a1c7f21bd012a0b29ba8ddbccb2c93b0d",
-        urls = [
-            "https://github.com/bazelbuild/bazel-skylib/releases/download/1.1.1/bazel-skylib-1.1.1.tar.gz",
-            "https://mirror.bazel.build/github.com/bazelbuild/bazel-skylib/releases/download/1.1.1/bazel-skylib-1.1.1.tar.gz",
-        ],
-    )
-    maybe(
-        http_archive,
-        name = "aspect_rules_js",
-        strip_prefix = "rules_js-1.42.0",
-        sha256 = "5a00869efaeb308245f8132a671fe86524bdfc4f8bfd1976d26f862b316dc3c9",
-        urls = ["https://github.com/aspect-build/rules_js/releases/download/v1.42.0/rules_js-v1.42.0.tar.gz"],
-    )
-
-    # Transitive dependencies of aspect_rules_js. We explicitly pull them here instead of calling their
-    # provided function to avoid requiring a call to rules_js_dependencies in WORKSPACE.
-    maybe(
-        http_archive,
-        name = "aspect_bazel_lib",
-        sha256 = "714cf8ce95a198bab0a6a3adaffea99e929d2f01bf6d4a59a2e6d6af72b4818c",
-        strip_prefix = "bazel-lib-2.7.8",
-        url = "https://github.com/aspect-build/bazel-lib/releases/download/v2.7.8/bazel-lib-v2.7.8.tar.gz",
-    )
-    maybe(
-        http_archive,
-        name = "rules_nodejs",
-        strip_prefix = "rules_nodejs-6.3.2",
-        sha256 = "158619723f1d8bd535dd6b93521f4e03cf24a5e107126d05685fbd9540ccad10",
-        urls = ["https://github.com/bazel-contrib/rules_nodejs/releases/download/v6.3.2/rules_nodejs-v6.3.2.tar.gz"],
-    )
-    http_archive(
-        name = "bazel_features",
-        sha256 = "f3082bfcdca73dc77dcd68faace806135a2e08c230b02b1d9fbdbd7db9d9c450",
-        strip_prefix = "bazel_features-0.1.0",
-        url = "https://github.com/bazel-contrib/bazel_features/releases/download/v0.1.0/bazel_features-v0.1.0.tar.gz",
-    )

bazel/emscripten_build_file.bzl

@@ -0,0 +1,93 @@
+"""A templated build file for emscripten repositories"""
+
+EMSCRIPTEN_BUILD_FILE_CONTENT_TEMPLATE = """
+package(default_visibility = ['//visibility:public'])
+
+filegroup(
+    name = "all",
+    srcs = glob(["**"]),
+)
+
+filegroup(
+    name = "includes",
+    srcs = glob([
+        "emscripten/cache/sysroot/include/c++/v1/**",
+        "emscripten/cache/sysroot/include/compat/**",
+        "emscripten/cache/sysroot/include/**",
+        "lib/clang/**/include/**",
+    ]),
+)
+
+filegroup(
+    name = "emcc_common",
+    srcs = [
+        "emscripten/emcc.py",
+        "emscripten/embuilder.py",
+        "emscripten/emscripten-version.txt",
+        "emscripten/cache/sysroot_install.stamp",
+        "emscripten/src/settings.js",
+        "emscripten/src/settings_internal.js",
+    ] + glob(
+        include = [
+            "emscripten/third_party/**",
+            "emscripten/tools/**",
+        ],
+        exclude = [
+            "**/__pycache__/**",
+        ],
+    ),
+)
+
+filegroup(
+    name = "compiler_files",
+    srcs = [
+        "bin/clang{bin_extension}",
+        "bin/clang++{bin_extension}",
+        ":emcc_common",
+        ":includes",
+    ],
+)
+
+filegroup(
+    name = "linker_files",
+    srcs = [
+        "bin/clang{bin_extension}",
+        "bin/llvm-ar{bin_extension}",
+        "bin/llvm-dwarfdump{bin_extension}",
+        "bin/llvm-nm{bin_extension}",
+        "bin/llvm-objcopy{bin_extension}",
+        "bin/wasm-ctor-eval{bin_extension}",
+        "bin/wasm-emscripten-finalize{bin_extension}",
+        "bin/wasm-ld{bin_extension}",
+        "bin/wasm-metadce{bin_extension}",
+        "bin/wasm-opt{bin_extension}",
+        "bin/wasm-split{bin_extension}",
+        "bin/wasm2js{bin_extension}",
+        ":emcc_common",
+    ] + glob(
+        include = [
+            "emscripten/cache/sysroot/lib/**",
+            "emscripten/node_modules/**",
+            "emscripten/src/**",
+        ],
+    ),
+)
+
+filegroup(
+    name = "ar_files",
+    srcs = [
+        "bin/llvm-ar{bin_extension}",
+        "emscripten/emar.py",
+        "emscripten/emscripten-version.txt",
+        "emscripten/src/settings.js",
+        "emscripten/src/settings_internal.js",
+    ] + glob(
+        include = [
+            "emscripten/tools/**",
+        ],
+        exclude = [
+            "**/__pycache__/**",
+        ],
+    ),
+)
+"""

bazel/emscripten_cache.bzl

@@ -10,46 +10,48 @@ LLVM_ROOT = '{llvm_root}'
 """
 
 def get_root_and_script_ext(repository_ctx):
-    if repository_ctx.os.name.startswith('linux'):
+    if repository_ctx.os.name.startswith("linux"):
-        if 'amd64' in repository_ctx.os.arch or 'x86_64' in repository_ctx.os.arch:
+        if "amd64" in repository_ctx.os.arch or "x86_64" in repository_ctx.os.arch:
-            return (repository_ctx.path(Label("@emscripten_bin_linux//:BUILD.bazel")).dirname, '')
+            return (repository_ctx.path(Label("@emscripten_bin_linux//:BUILD.bazel")).dirname, "")
-        elif 'aarch64' in repository_ctx.os.arch:
+        elif "aarch64" in repository_ctx.os.arch:
-            return (repository_ctx.path(Label("@emscripten_bin_linux_arm64//:BUILD.bazel")).dirname, '')
+            return (repository_ctx.path(Label("@emscripten_bin_linux_arm64//:BUILD.bazel")).dirname, "")
         else:
-            fail('Unsupported architecture for Linux')
+            fail("Unsupported architecture for Linux")
-    elif repository_ctx.os.name.startswith('mac'):
+    elif repository_ctx.os.name.startswith("mac"):
-        if 'amd64' in repository_ctx.os.arch or 'x86_64' in repository_ctx.os.arch:
+        if "amd64" in repository_ctx.os.arch or "x86_64" in repository_ctx.os.arch:
-            return (repository_ctx.path(Label("@emscripten_bin_mac//:BUILD.bazel")).dirname, '')
+            return (repository_ctx.path(Label("@emscripten_bin_mac//:BUILD.bazel")).dirname, "")
-        elif 'aarch64' in repository_ctx.os.arch:
+        elif "aarch64" in repository_ctx.os.arch:
-            return (repository_ctx.path(Label("@emscripten_bin_mac_arm64//:BUILD.bazel")).dirname, '')
+            return (repository_ctx.path(Label("@emscripten_bin_mac_arm64//:BUILD.bazel")).dirname, "")
         else:
-            fail('Unsupported architecture for MacOS')
+            fail("Unsupported architecture for MacOS")
-    elif repository_ctx.os.name.startswith('windows'):
+    elif repository_ctx.os.name.startswith("windows"):
-        return (repository_ctx.path(Label("@emscripten_bin_win//:BUILD.bazel")).dirname, '.bat')
+        return (repository_ctx.path(Label("@emscripten_bin_win//:BUILD.bazel")).dirname, ".bat")
     else:
-        fail('Unsupported operating system')
+        fail("Unsupported operating system")
 
-def _emscripten_cache_impl(repository_ctx):
+def _emscripten_cache_repository_impl(repository_ctx):
     # Read the default emscripten configuration file
     default_config = repository_ctx.read(
         repository_ctx.path(
-            Label("@emsdk//emscripten_toolchain:default_config")
+            Label("@emsdk//emscripten_toolchain:default_config"),
-        )
+        ),
     )
 
     if repository_ctx.attr.targets or repository_ctx.attr.configuration:
         root, script_ext = get_root_and_script_ext(repository_ctx)
         llvm_root = root.get_child("bin")
         cache = repository_ctx.path("cache")
+
         # Create configuration file
         embuilder_config_content = EMBUILDER_CONFIG_TEMPLATE.format(
-            cache=cache,
+            cache = cache,
-            binaryen_root=root,
+            binaryen_root = root,
-            llvm_root=llvm_root,
+            llvm_root = llvm_root,
         )
         repository_ctx.file("embuilder_config", embuilder_config_content)
         embuilder_config_path = repository_ctx.path("embuilder_config")
         embuilder_path = "{}{}".format(root.get_child("emscripten").get_child("embuilder"), script_ext)
+
         # Prepare the command line
         if repository_ctx.attr.targets:
             targets = repository_ctx.attr.targets
@@ -58,38 +60,54 @@ def _emscripten_cache_impl(repository_ctx):
             targets = ["ALL"]
         flags = ["--em-config", embuilder_config_path] + repository_ctx.attr.configuration
         embuilder_args = [embuilder_path] + flags + ["build"] + targets
+
         # Run embuilder
         repository_ctx.report_progress("Building secondary cache")
         result = repository_ctx.execute(
             embuilder_args,
-            quiet=True,
+            quiet = True,
             environment = {
                 "EM_IGNORE_SANITY": "1",
                 "EM_NODE_JS": "empty",
-            }
+            },
         )
         if result.return_code != 0:
             fail("Embuilder exited with a non-zero return code")
+
         # Override Emscripten's cache with the secondary cache
         default_config += "CACHE = '{}'\n".format(cache)
 
     # Create the configuration file for the toolchain and export
-    repository_ctx.file('emscripten_config', default_config)
+    repository_ctx.file("emscripten_config", default_config)
-    repository_ctx.file('BUILD.bazel', BUILD_FILE_CONTENT_TEMPLATE)
+    repository_ctx.file("BUILD.bazel", BUILD_FILE_CONTENT_TEMPLATE)
 
-_emscripten_cache = repository_rule(
+_emscripten_cache_repository = repository_rule(
-    implementation = _emscripten_cache_impl,
+    implementation = _emscripten_cache_repository_impl,
     attrs = {
         "configuration": attr.string_list(),
         "targets": attr.string_list(),
     },
 )
 
-def register_emscripten_toolchains(cache = {}):
+def _emscripten_cache_impl(ctx):
-    _emscripten_cache(
+    all_configuration = []
+    all_targets = []
+    for mod in ctx.modules:
+        for configuration in mod.tags.configuration:
+            all_configuration += configuration.flags
+        for targets in mod.tags.targets:
+            all_targets += targets.targets
+
+    _emscripten_cache_repository(
         name = "emscripten_cache",
-        configuration = cache["configuration"] if "configuration" in cache else [],
+        configuration = all_configuration,
-        targets = cache["targets"] if "targets" in cache else [],
+        targets = all_targets,
     )
 
-    native.register_toolchains(str(Label("//emscripten_toolchain:cc-toolchain-wasm")))
+emscripten_cache = module_extension(
+    tag_classes = {
+        "configuration": tag_class(attrs = {"flags": attr.string_list()}),
+        "targets": tag_class(attrs = {"targets": attr.string_list()}),
+    },
+    implementation = _emscripten_cache_impl,
+)

bazel/emscripten_deps.bzl

@@ -1,210 +1,99 @@
-load("@aspect_rules_js//npm:repositories.bzl", "npm_translate_lock")
+load(":remote_emscripten_repository.bzl", "remote_emscripten_repository")
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-load("@rules_nodejs//nodejs:repositories.bzl", "nodejs_register_toolchains")
 load(":revisions.bzl", "EMSCRIPTEN_TAGS")
 
 def _parse_version(v):
     return [int(u) for u in v.split(".")]
 
-BUILD_FILE_CONTENT_TEMPLATE = """
+def _empty_repository_impl(ctx):
-package(default_visibility = ['//visibility:public'])
+    ctx.file("MODULE.bazel", """module(name = "{}")""".format(ctx.name))
+    ctx.file("BUILD.bazel", "")
 
-filegroup(
+_empty_repository = repository_rule(
-    name = "all",
+    implementation = _empty_repository_impl,
-    srcs = glob(["**"]),
 )
 
-filegroup(
+def emscripten_repo_name(name):
-    name = "includes",
+    return "emscripten_bin_{}".format(name)
-    srcs = glob([
-        "emscripten/cache/sysroot/include/c++/v1/**",
-        "emscripten/cache/sysroot/include/compat/**",
-        "emscripten/cache/sysroot/include/**",
-        "lib/clang/**/include/**",
-    ]),
-)
 
-filegroup(
+def _emscripten_deps_impl(ctx):
-    name = "emcc_common",
+    version = None
-    srcs = [
-        "emscripten/emcc.py",
-        "emscripten/embuilder.py",
-        "emscripten/emscripten-version.txt",
-        "emscripten/cache/sysroot_install.stamp",
-        "emscripten/src/settings.js",
-        "emscripten/src/settings_internal.js",
-    ] + glob(
-        include = [
-            "emscripten/third_party/**",
-            "emscripten/tools/**",
-        ],
-        exclude = [
-            "**/__pycache__/**",
-        ],
-    ),
-)
 
-filegroup(
+    for mod in ctx.modules:
-    name = "compiler_files",
+        for config in mod.tags.config:
-    srcs = [
+            if config.version and version != None:
-        "bin/clang{bin_extension}",
+                fail("More than one emscripten version specified!")
-        "bin/clang++{bin_extension}",
+            version = config.version
-        ":emcc_common",
+    if version == None:
-        ":includes",
+        version = "latest"
-    ],
-)
-
-filegroup(
-    name = "linker_files",
-    srcs = [
-        "bin/clang{bin_extension}",
-        "bin/llvm-ar{bin_extension}",
-        "bin/llvm-dwarfdump{bin_extension}",
-        "bin/llvm-nm{bin_extension}",
-        "bin/llvm-objcopy{bin_extension}",
-        "bin/wasm-ctor-eval{bin_extension}",
-        "bin/wasm-emscripten-finalize{bin_extension}",
-        "bin/wasm-ld{bin_extension}",
-        "bin/wasm-metadce{bin_extension}",
-        "bin/wasm-opt{bin_extension}",
-        "bin/wasm-split{bin_extension}",
-        "bin/wasm2js{bin_extension}",
-        ":emcc_common",
-    ] + glob(
-        include = [
-            "emscripten/cache/sysroot/lib/**",
-            "emscripten/node_modules/**",
-            "emscripten/src/**",
-        ],
-    ),
-)
-
-filegroup(
-    name = "ar_files",
-    srcs = [
-        "bin/llvm-ar{bin_extension}",
-        "emscripten/emar.py",
-        "emscripten/emscripten-version.txt",
-        "emscripten/src/settings.js",
-        "emscripten/src/settings_internal.js",
-    ] + glob(
-        include = [
-            "emscripten/tools/**",
-        ],
-        exclude = [
-            "**/__pycache__/**",
-        ],
-    ),
-)
-"""
-
-def emscripten_deps(emscripten_version = "latest"):
-    version = emscripten_version
 
     if version == "latest":
         version = reversed(sorted(EMSCRIPTEN_TAGS.keys(), key = _parse_version))[0]
 
-    if version not in EMSCRIPTEN_TAGS.keys():
-        error_msg = "Emscripten version {} not found.".format(version)
-        error_msg += " Look at @emsdk//:revisions.bzl for the list "
-        error_msg += "of currently supported versions."
-        fail(error_msg)
-
     revision = EMSCRIPTEN_TAGS[version]
 
     emscripten_url = "https://storage.googleapis.com/webassembly/emscripten-releases-builds/{}/{}/wasm-binaries{}.{}"
 
-    # This could potentially backfire for projects with multiple emscripten
+    remote_emscripten_repository(
-    # dependencies that use different emscripten versions
+        name = emscripten_repo_name("linux"),
-    excludes = native.existing_rules().keys()
+        bin_extension = "",
-    if "nodejs_toolchains" not in excludes:
+        sha256 = revision.sha_linux,
-        # Node 16 is the first version that supports darwin_arm64
+        strip_prefix = "install",
-        nodejs_register_toolchains(
+        type = "tar.xz",
-            node_version = "20.18.0",
+        url = emscripten_url.format("linux", revision.hash, "", "tar.xz"),
-        )
+    )
 
-    if "emscripten_bin_linux" not in excludes:
+    # Not all versions have a linux/arm64 release: https://github.com/emscripten-core/emsdk/issues/547
-        http_archive(
+    if hasattr(revision, "sha_linux_arm64"):
-            name = "emscripten_bin_linux",
+        remote_emscripten_repository(
+            name = emscripten_repo_name("linux_arm64"),
+            bin_extension = "",
+            sha256 = revision.sha_linux_arm64,
             strip_prefix = "install",
-            url = emscripten_url.format("linux", revision.hash, "", "tar.xz"),
-            sha256 = revision.sha_linux,
-            build_file_content = BUILD_FILE_CONTENT_TEMPLATE.format(bin_extension = ""),
             type = "tar.xz",
-        )
-
-    if "emscripten_bin_linux_arm64" not in excludes:
-        http_archive(
-            name = "emscripten_bin_linux_arm64",
-            strip_prefix = "install",
             url = emscripten_url.format("linux", revision.hash, "-arm64", "tar.xz"),
-            # Not all versions have a linux/arm64 release: https://github.com/emscripten-core/emsdk/issues/547
+        )
-            sha256 = getattr(revision, "sha_linux_arm64", None),
+    else:
-            build_file_content = BUILD_FILE_CONTENT_TEMPLATE.format(bin_extension = ""),
+        _empty_repository(
-            type = "tar.xz",
+            name = emscripten_repo_name("linux_arm64"),
         )
 
-    if "emscripten_bin_mac" not in excludes:
+    remote_emscripten_repository(
-        http_archive(
+        name = emscripten_repo_name("mac"),
-            name = "emscripten_bin_mac",
+        bin_extension = "",
-            strip_prefix = "install",
+        sha256 = revision.sha_mac,
-            url = emscripten_url.format("mac", revision.hash, "", "tar.xz"),
+        strip_prefix = "install",
-            sha256 = revision.sha_mac,
+        type = "tar.xz",
-            build_file_content = BUILD_FILE_CONTENT_TEMPLATE.format(bin_extension = ""),
+        url = emscripten_url.format("mac", revision.hash, "", "tar.xz"),
-            type = "tar.xz",
+    )
-        )
 
-    if "emscripten_bin_mac_arm64" not in excludes:
+    remote_emscripten_repository(
-        http_archive(
+        name = emscripten_repo_name("mac_arm64"),
-            name = "emscripten_bin_mac_arm64",
+        bin_extension = "",
-            strip_prefix = "install",
+        sha256 = revision.sha_mac_arm64,
-            url = emscripten_url.format("mac", revision.hash, "-arm64", "tar.xz"),
+        strip_prefix = "install",
-            sha256 = revision.sha_mac_arm64,
+        type = "tar.xz",
-            build_file_content = BUILD_FILE_CONTENT_TEMPLATE.format(bin_extension = ""),
+        url = emscripten_url.format("mac", revision.hash, "-arm64", "tar.xz"),
-            type = "tar.xz",
+    )
-        )
 
-    if "emscripten_bin_win" not in excludes:
+    remote_emscripten_repository(
-        http_archive(
+        name = emscripten_repo_name("win"),
-            name = "emscripten_bin_win",
+        bin_extension = ".exe",
-            strip_prefix = "install",
+        sha256 = revision.sha_win,
-            url = emscripten_url.format("win", revision.hash, "", "zip"),
+        strip_prefix = "install",
-            sha256 = revision.sha_win,
+        type = "zip",
-            build_file_content = BUILD_FILE_CONTENT_TEMPLATE.format(bin_extension = ".exe"),
+        url = emscripten_url.format("win", revision.hash, "", "zip"),
-            type = "zip",
+    )
-        )
 
-    if "emscripten_npm_linux" not in excludes:
+emscripten_deps = module_extension(
-        npm_translate_lock(
+    tag_classes = {
-            name = "emscripten_npm_linux",
+        "config": tag_class(
-            data = ["@emscripten_bin_linux//:emscripten/package.json"],
+            attrs = {
-            npm_package_lock = "@emscripten_bin_linux//:emscripten/package-lock.json",
+                "version": attr.string(
-        )
+                    doc = "Version to use. 'latest' to use latest.",
-
+                    values = ["latest"] + EMSCRIPTEN_TAGS.keys(),
-    if "emscripten_npm_linux_arm64" not in excludes:
+                ),
-        npm_translate_lock(
+            },
-            name = "emscripten_npm_linux_arm64",
+        ),
-            data = ["@emscripten_bin_linux_arm64//:emscripten/package.json"],
+    },
-            npm_package_lock = "@emscripten_bin_linux_arm64//:emscripten/package-lock.json",
+    implementation = _emscripten_deps_impl,
-        )
+)
-
-    if "emscripten_npm_mac" not in excludes:
-        npm_translate_lock(
-            name = "emscripten_npm_mac",
-            data = ["@emscripten_bin_mac//:emscripten/package.json"],
-            npm_package_lock = "@emscripten_bin_mac//:emscripten/package-lock.json",
-        )
-
-    if "emscripten_npm_mac_arm64" not in excludes:
-        npm_translate_lock(
-            name = "emscripten_npm_mac",
-            data = ["@emscripten_bin_mac_arm64//:emscripten/package.json"],
-            npm_package_lock = "@emscripten_bin_mac_arm64//:emscripten/package-lock.json",
-        )
-
-    if "emscripten_npm_win" not in excludes:
-        npm_translate_lock(
-            name = "emscripten_npm_win",
-            data = ["@emscripten_bin_win//:emscripten/package.json"],
-            npm_package_lock = "@emscripten_bin_win//:emscripten/package-lock.json",
-        )

bazel/emscripten_toolchain/BUILD.bazel

@@ -1,101 +1,40 @@
-load(":toolchain.bzl", "emscripten_cc_toolchain_config_rule")
+load("//:emscripten_deps.bzl", "emscripten_repo_name")
+load("//:remote_emscripten_repository.bzl", "create_toolchains", "emscripten_toolchain_name")
+load("@rules_python//python:py_binary.bzl", "py_binary")
 
 package(default_visibility = ["//visibility:public"])
 
-filegroup(
-    name = "common_files",
-    srcs = [
-        "@emscripten_cache//:emscripten_config",
-        "env.sh",
-        "env.bat",
-        "@nodejs//:node_files",
-    ],
-)
-
-filegroup(
-    name = "compiler_files",
-    srcs = [
-        "emcc.sh",
-        "emcc.bat",
-        "@emsdk//:compiler_files",
-        ":common_files",
-    ],
-)
-
-filegroup(
-    name = "linker_files",
-    srcs = [
-        "emcc_link.sh",
-        "emcc_link.bat",
-        "link_wrapper.py",
-        "@emsdk//:linker_files",
-        ":common_files",
-    ],
-)
-
-filegroup(
-    name = "ar_files",
-    srcs = [
-        "emar.sh",
-        "emar.bat",
-        "@emsdk//:ar_files",
-        ":common_files",
-    ],
-)
-
-filegroup(
-    name = "all_files",
-    srcs = [
-        ":ar_files",
-        ":compiler_files",
-        ":linker_files",
-    ],
-)
-
-filegroup(name = "empty")
-
 # dlmalloc.bc is implicitly added by the emscripten toolchain
 cc_library(name = "malloc")
 
-emscripten_cc_toolchain_config_rule(
+create_toolchains(
-    name = "wasm",
+    name = emscripten_toolchain_name("linux"),
-    cpu = "wasm",
+    repo_name = emscripten_repo_name("linux"),
-    em_config = "@emscripten_cache//:emscripten_config",
+    exec_compatible_with = [ "@platforms//os:linux", "@platforms//cpu:x86_64"],
-    emscripten_binaries = "@emsdk//:compiler_files",
-    nodejs_bin = "@nodejs//:node",
-    script_extension = select({
-        "@bazel_tools//src/conditions:host_windows": "bat",
-        "//conditions:default": "sh",
-    }),
 )
 
-cc_toolchain(
+create_toolchains(
-    name = "cc-compiler-wasm",
+    name = emscripten_toolchain_name("linux_arm64"),
-    all_files = ":all_files",
+    repo_name = emscripten_repo_name("linux_arm64"),
-    ar_files = ":ar_files",
+    exec_compatible_with = ["@platforms//os:linux", "@platforms//cpu:arm64"],
-    as_files = ":empty",
-    compiler_files = ":compiler_files",
-    dwp_files = ":empty",
-    linker_files = ":linker_files",
-    objcopy_files = ":empty",
-    strip_files = ":empty",
-    toolchain_config = "wasm",
-    toolchain_identifier = "emscripten-wasm",
 )
 
-cc_toolchain_suite(
+create_toolchains(
-    name = "everything",
+    name = emscripten_toolchain_name("mac"),
-    toolchains = {
+    repo_name = emscripten_repo_name("mac"),
-        "wasm": ":cc-compiler-wasm",
+    exec_compatible_with = ["@platforms//os:macos", "@platforms//cpu:x86_64"],
-        "wasm|emscripten": ":cc-compiler-wasm",
-    },
 )
 
-toolchain(
+create_toolchains(
-    name = "cc-toolchain-wasm",
+    name = emscripten_toolchain_name("mac_arm64"),
-    target_compatible_with = ["@platforms//cpu:wasm32"],
+    repo_name = emscripten_repo_name("mac_arm64"),
-    toolchain = ":cc-compiler-wasm",
+    exec_compatible_with = ["@platforms//os:macos", "@platforms//cpu:arm64"],
-    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
+
+create_toolchains(
+    name = emscripten_toolchain_name("win"),
+    repo_name = emscripten_repo_name("win"),
+    exec_compatible_with = ["@platforms//os:windows", "@platforms//cpu:x86_64"],
 )
 
 py_binary(

bazel/emscripten_toolchain/emar.bat

@@ -1,5 +1,5 @@
 @ECHO OFF
 
-call external\emsdk\emscripten_toolchain\env.bat
+call %~dp0\env.bat
 
 py -3 %EMSCRIPTEN%\emar.py %*

bazel/emscripten_toolchain/emcc.bat

@@ -1,5 +1,5 @@
 @ECHO OFF
 
-call external\emsdk\emscripten_toolchain\env.bat
+call %~dp0\env.bat
 
 py -3 %EMSCRIPTEN%\emcc.py %*

bazel/emscripten_toolchain/emcc_link.bat

@@ -1,5 +1,5 @@
 @ECHO OFF
 
-call external\emsdk\emscripten_toolchain\env.bat
+call %~dp0\env.bat
 
-py -3 external\emsdk\emscripten_toolchain\link_wrapper.py %*
+py -3 %~dp0\link_wrapper.py %*

bazel/emscripten_toolchain/env.bat

@@ -1,5 +1,6 @@
 @ECHO OFF
 
-set ROOT_DIR=%CD%
+set ROOT_DIR=%EXT_BUILD_ROOT%
+if "%ROOT_DIR%"=="" set ROOT_DIR=%CD%
 set EMSCRIPTEN=%ROOT_DIR%\%EM_BIN_PATH%\emscripten
 set EM_CONFIG=%ROOT_DIR%\%EM_CONFIG_PATH%

bazel/emscripten_toolchain/toolchain.bzl

@@ -71,6 +71,7 @@ def _impl(ctx):
     cc_target_os = "emscripten"
 
     emscripten_dir = ctx.attr.emscripten_binaries.label.workspace_root
+
     nodejs_path = ctx.file.nodejs_bin.path
 
     builtin_sysroot = emscripten_dir + "/emscripten/cache/sysroot"

bazel/emscripten_toolchain/wasm_cc_binary.bzl

@@ -32,12 +32,13 @@ def _wasm_transition_impl(settings, attr):
 
     return {
         "//command_line_option:compiler": "emscripten",
-        "//command_line_option:crosstool_top": "@emsdk//emscripten_toolchain:everything",
         "//command_line_option:cpu": "wasm",
         "//command_line_option:features": features,
         "//command_line_option:dynamic_mode": "off",
         "//command_line_option:linkopt": linkopts,
         "//command_line_option:platforms": [platform],
+        # This is hardcoded to an empty cc_library because the malloc library
+        # is implicitly added by the emscripten toolchain
         "//command_line_option:custom_malloc": "@emsdk//emscripten_toolchain:malloc",
     }
 
@@ -50,7 +51,6 @@ _wasm_transition = transition(
     outputs = [
         "//command_line_option:compiler",
         "//command_line_option:cpu",
-        "//command_line_option:crosstool_top",
         "//command_line_option:features",
         "//command_line_option:dynamic_mode",
         "//command_line_option:linkopt",

bazel/remote_emscripten_repository.bzl

@@ -0,0 +1,148 @@
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+load(":emscripten_build_file.bzl", "EMSCRIPTEN_BUILD_FILE_CONTENT_TEMPLATE")
+load(":revisions.bzl", "EMSCRIPTEN_TAGS")
+load("//emscripten_toolchain:toolchain.bzl", "emscripten_cc_toolchain_config_rule")
+
+def remote_emscripten_repository(
+    name,
+    bin_extension,
+    **kwargs,
+):
+    """Imports an Emscripten from an http archive
+
+    Args:
+      name: A unique name for this Emscripten repository.
+      bin_extension: Extension for the binaries in this Emscripten repository
+      **kwargs: Args for http_archive. Refer to http_archive documentation for more info.
+    """
+    http_archive(
+        name = name,
+        build_file_content = EMSCRIPTEN_BUILD_FILE_CONTENT_TEMPLATE.format(bin_extension = bin_extension),
+        **kwargs
+    )
+
+def emscripten_toolchain_name(name):
+    return "emscripten_{}".format(name)
+
+def _get_name_and_target(name):
+    return name, ":" + name
+
+def create_toolchains(name, repo_name, exec_compatible_with):
+    """Creates toolchain definition for an Emscripten
+
+    Register the toolchains defined by this macro via
+    `register_toolchains("//<path-to-target>:cc-toolchain-wasm-<name>")`
+
+    Args:
+      name: A unique name for this Emscripten toolchain
+      repo_name: The name of the Emscripten repository for this toolchain
+      exec_compatible_with: Execute platform constraints for the Emscripten toolchain associated
+        with this repository.
+      **kwargs: Args for http_archive. Refer to http_archive documentation for more info.
+    """
+    common_files_name, common_files_target = _get_name_and_target("common_files_" + name)
+    compiler_files_name, compiler_files_target = _get_name_and_target("compiler_files_" + name)
+    linker_files_name, linker_files_target = _get_name_and_target("linker_files_" + name)
+    ar_files_name, ar_files_target = _get_name_and_target("ar_files_" + name)
+    all_files_name, all_files_target = _get_name_and_target("all_files_" + name)
+    cc_wasm_name, cc_wasm_target = _get_name_and_target("cc-compiler-wasm-" + name)
+
+    wasm_name = "wasm-" + name
+
+    # These are file groups defined by the build_file_content on the Emscripten http_archive
+    remote_repo = "@{}//".format(repo_name)
+    repo_compiler_files_target = remote_repo + ":compiler_files"
+    repo_linker_files_target = remote_repo + ":linker_files"
+    repo_ar_files_target = remote_repo + ":ar_files"
+
+    native.filegroup(
+        name = common_files_name,
+        srcs = [
+            "@emscripten_cache//:emscripten_config",
+            "@emsdk//emscripten_toolchain:env.sh",
+            "@emsdk//emscripten_toolchain:env.bat",
+            "@nodejs//:node_files",
+        ],
+    )
+
+    native.filegroup(
+        name = compiler_files_name,
+        srcs = [
+            "@emsdk//emscripten_toolchain:emcc.sh",
+            "@emsdk//emscripten_toolchain:emcc.bat",
+            repo_compiler_files_target,
+            common_files_target,
+        ],
+    )
+
+    native.filegroup(
+        name = linker_files_name,
+        srcs = [
+            "@emsdk//emscripten_toolchain:emcc_link.sh",
+            "@emsdk//emscripten_toolchain:emcc_link.bat",
+            "link_wrapper.py",
+            repo_linker_files_target,
+            common_files_target,
+        ],
+    )
+
+    native.filegroup(
+        name = ar_files_name,
+        srcs = [
+            "@emsdk//emscripten_toolchain:emar.sh",
+            "@emsdk//emscripten_toolchain:emar.bat",
+            repo_ar_files_target,
+            common_files_target,
+        ],
+    )
+
+    native.filegroup(
+        name = all_files_name,
+        srcs = [
+            ar_files_target,
+            compiler_files_target,
+            linker_files_target,
+        ],
+    )
+
+    emscripten_cc_toolchain_config_rule(
+        name = wasm_name,
+        cpu = "wasm",
+        em_config = "@emscripten_cache//:emscripten_config",
+        emscripten_binaries = repo_compiler_files_target,
+        nodejs_bin = "@nodejs//:node",
+        script_extension = select({
+            "@bazel_tools//src/conditions:host_windows": "bat",
+            "//conditions:default": "sh",
+        }),
+    )
+
+    native.cc_toolchain(
+        name = cc_wasm_name,
+        all_files = all_files_target,
+        ar_files = ar_files_target,
+        as_files = ":empty",
+        compiler_files = compiler_files_target,
+        dwp_files = ":empty",
+        linker_files = linker_files_target,
+        objcopy_files = ":empty",
+        strip_files = ":empty",
+        toolchain_config = wasm_name,
+        toolchain_identifier = "emscripten-wasm-" + name,
+    )
+
+    native.toolchain(
+        name = "cc-toolchain-wasm-" + name,
+        target_compatible_with = ["@platforms//cpu:wasm32"],
+        exec_compatible_with = exec_compatible_with,
+        toolchain = cc_wasm_target,
+        toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+    )
+
+    native.cc_toolchain_suite(
+        name = "everything-" + name,
+        toolchains = {
+            "wasm": cc_wasm_target,
+            "wasm|emscripten": cc_wasm_target,
+        },
+    )

bazel/revisions.bzl

@@ -5,6 +5,7 @@ EMSCRIPTEN_TAGS = {
     "4.0.6": struct(
         hash = "14767574a5c37ff9526a253a65ddbe0811cb3667",
         sha_linux = "27fc220a9ad98d323cad73531ff563e9838c9e1205f51ee2a5632bb4266a35d2",
+        sha_linux_arm64 = "2d03f8eb3f81dd94821658eefbb442a92b0b7601f4cfb08590590fd7bc467ef8",
         sha_mac = "c06048915595726fc2e2da6a8db3134581a6287645fb818802a9734ff9785e77",
         sha_mac_arm64 = "35d743453d0f91857b09f00d721037bb46753aaeae373bd7f64746338db11770",
         sha_win = "3b576e825b26426bb72854ed98752df3fcb58cc3ab1dc116566e328b79a8abb3",
@@ -12,6 +13,7 @@ EMSCRIPTEN_TAGS = {
     "4.0.5": struct(
         hash = "d7f8ff5e2ca3539c33fae81e98f7c56ef9fa1239",
         sha_linux = "fdd4d9d6b37e845039b207baaef60cd98fb594ea13a3e6d622c2dcd8f2a48ac6",
+        sha_linux_arm64 = "0007aec32eee609b91f35c32481ec060ea7dac7151e36344bbcae419907f9240",
         sha_mac = "f4e5a6c57ad9de59bff73463972213a299af2bb419dafbdd3959947fa801a342",
         sha_mac_arm64 = "b8b93190fa17afe32a5eaa7120b807767b1c9d6e1d4ae6b9a2c6adb231758683",
         sha_win = "3b8ed9e298a6d58fee841f5c3f1d3e7b2dff104cc7df314cd329f4c05d470be0",
@@ -19,6 +21,7 @@ EMSCRIPTEN_TAGS = {
     "4.0.4": struct(
         hash = "ea71afcf5a172125179a07ff1731de6e81c92222",
         sha_linux = "f05dab4a6a13a5fe6972e95e918d1483e687faf468e1a653deaa8d7956a97a3a",
+        sha_linux_arm64 = "95a421f304a7209c6f259754ad15aea5bbbbb1838139b51837aeb2c184fa4a89",
         sha_mac = "d8b44aae37224ae76572ad84b60a2adaa126826332864fb689944d5130705d8d",
         sha_mac_arm64 = "ade1c1a0c2e5893c6f74079beeae8b7e2a0c3f3b7ae88891064104fd985dfc2b",
         sha_win = "342cf9dfb83e95bf678d07e460e093ea61a609d34b4603d9be06d4f31784409d",
@@ -26,6 +29,7 @@ EMSCRIPTEN_TAGS = {
     "4.0.3": struct(
         hash = "de2109f0e5e7278d470da11de526aed16c527722",
         sha_linux = "6480f51d0c24130424c696bf83e9774f42246a0109c8d48b59f4520fdfadb928",
+        sha_linux_arm64 = "76b1511d550b4f47276b93581ae5122063acbca7c960703637657388cf178636",
         sha_mac = "f40851b816b31b3ca3214ebf61cc152625a05c24f43e2b13c2ad9b9e5dca73c0",
         sha_mac_arm64 = "6d8ac5ad1f59f71de0927eb2c595dab2f21d9946ca293434359a6db2ab06a138",
         sha_win = "3702e4a518057520d4ad9e7cd63a01a829770d090551e00f19f417f55b0170d3",
@@ -33,6 +37,7 @@ EMSCRIPTEN_TAGS = {
     "4.0.2": struct(
         hash = "cc8eba40de8235f9c33d92463018f87b3edaa09e",
         sha_linux = "3c0e3940240709388c24a4262680c18bb1d5979f2337abe53db00fb039606c44",
+        sha_linux_arm64 = "21ed0c31c1fc972e3509fcb140e0323061b5f2b173fe56d1f8961df2a37e4c11",
         sha_mac = "e1bd96ec790968adf583d348158375b76ee0287e348954c3393c82565475b07b",
         sha_mac_arm64 = "e5bf9a5efabc114b42636abcea07a1e02d3a9406cd399a29ccbc730586dce465",
         sha_win = "78010f8e2f7bb6868bb20e3fc32e24d45e6fca749c388c2d25bea9845512338d",
@@ -40,6 +45,7 @@ EMSCRIPTEN_TAGS = {
     "4.0.1": struct(
         hash = "5ff495a591978fdf8a16f2d172be3616f3150d1e",
         sha_linux = "7b2b64b1bc15555696f78cbcb54c8d75832222d1578270ff5f56a8024c9a0dbc",
+        sha_linux_arm64 = "5c046a22b933de14be6b2522b75796afffe3940a19422eee483b7f3f1a226d66",
         sha_mac = "d089eba9c3cad675bbd7d3318aec166ebe5ba984a6c5291136c09c68324d9818",
         sha_mac_arm64 = "c8359b334bad71719e8d29e796ca7b63891e0305987b2572eb5a2f020e34f773",
         sha_win = "9cf861339327f3657281c5c8c18aa723323acffe3b3d1c3807b9d4576d097e0e",
@@ -47,6 +53,7 @@ EMSCRIPTEN_TAGS = {
     "4.0.0": struct(
         hash = "3ebc04a3dab24522a5bf8ced3ce3caea816558f6",
         sha_linux = "6836988f0b7ee6ce3df5192dd4375b9eee55be78847ce31cf1d2abfb00f1e991",
+        sha_linux_arm64 = "d4e6e04b7e2fa1bdffc9c07ab4e0a3f66bde75adb06ebf9cc66a341907b17db4",
         sha_mac = "4123e9ff6a699dac303c4fe22529ae0d618c118fcd8267df590363b0fc98c91d",
         sha_mac_arm64 = "4b5fb7cc4f5f8526aaa41c8560a00ad6782b97cd3894d856beb635f05a825613",
         sha_win = "6b1e5aee4b4a4274712566c845888bdf4eced09a5aaa64c1796cda57cd2854c4",
@@ -54,6 +61,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.74": struct(
         hash = "c2655005234810c7c42e02a18e4696554abe0352",
         sha_linux = "a987bb4cded4f29437e8589accac204ce3c134feaaaf251bb97d0fdf450dce65",
+        sha_linux_arm64 = "c7fcc532eb7ee1dc7df0eacb49128ded12e4d55a973b8a2a5215da8bb6c4027c",
         sha_mac = "04f848f40bd19220a43abde2dd1012d95bf1f89c618c0f631b83d18357e2bb65",
         sha_mac_arm64 = "fc71758a5bfb02b8a5c2dd21d6bfc34aa3c64698f6105e204a1f4d11f6d67603",
         sha_win = "603b0515e0367ee2718b2f360ef0194663d23a91236910d5f4a90ac4d745a4f2",
@@ -61,6 +69,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.73": struct(
         hash = "b363a836e75a245c548b7a6a021822d8c9e4c6df",
         sha_linux = "4f3bc91cffec9096c3d3ccb11c222e1c2cb7734a0ff9a92d192e171849e68f28",
+        sha_linux_arm64 = "e6fb8a32889d4e4a3ac3e45d8012641369251ddd1255ada132ff6c70ab62b932",
         sha_mac = "8d52ec080834f49996534de26772800dee048ec9bf148bb508be95887e267735",
         sha_mac_arm64 = "58e6c984c5a1fb71e0871f0c3bb9e32d41e7553260c6eeb38800a4612623a99d",
         sha_win = "d76003fad2146ad1f2289e8b251fbc359406ced0857f141a41f15149c2138302",
@@ -68,6 +77,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.72": struct(
         hash = "7a360458327cd24c2a7aab428bdbcb5bca8810e4",
         sha_linux = "be094d6dd27c27a64116e9c0165d6cade5d329f5137e56696773e98e1df83fa7",
+        sha_linux_arm64 = "5dba64454809d72d53c432f3c91830d69d413ebd9dcd0ce18df5a79a3af235a6",
         sha_mac = "52f713c118717814d2371912ab9019a3605b7d6acc627f3842e6aa7d3ffff7bf",
         sha_mac_arm64 = "644593539684f59c635c7eae2e743f5e4e27b1d665f9c71c23dcefd4c2448b3c",
         sha_win = "c72623fb68f109d8f122036f25b9fc75353bd1ce28995d9920277d4be4a1d99c",
@@ -75,6 +85,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.71": struct(
         hash = "7ee0f9488f152e9e9cf0d4d243970e03742f1a5c",
         sha_linux = "43f87aa84a73697b905d2a13c89d016af8ec66bed792f37dd5a0059529abee12",
+        sha_linux_arm64 = "d25f5e57b2e7557df39cd9dec3b0283fb086f66c800af3d9a3f70f36c5fc6b14",
         sha_mac = "8dac015c03c4f2e594d8bca25fe35d1e4d808aea81705121e852aff0464c4a9d",
         sha_mac_arm64 = "a7797c3d210eda29f88eede261fc8f0aabf22c7b05214916b5b50a1271e9f0b8",
         sha_win = "dfe77eaf22278ca975519f0497c8b336c86e52461c478060418fe67b39b6e87c",
@@ -82,6 +93,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.70": struct(
         hash = "6fa6145af41e835f3d13edf7d308c08e4573357a",
         sha_linux = "c29b4a2c6addd5aafa613768d34273a23d8fcd1753c685ff61099506710cd8d7",
+        sha_linux_arm64 = "b13386975023a06f19057daef3896d480229b144d1e97f8764ed2f3e0fcb7d37",
         sha_mac = "bc0edcaaaa19daeda9164d38d36c5f7d7b4b4e1eb7695ad58e776336c571fcc4",
         sha_mac_arm64 = "e470d5eeb570850d66a79bd4c06064b9b3a1e90c7c2101e1a444ebcd6466fe5a",
         sha_win = "f0118d71fd67583ddcfd39af2ed8bec3d18152fb6aadee085ebec5bcaf4ac4f5",
@@ -89,6 +101,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.69": struct(
         hash = "8fe01288bc35668c13316324336ea00195dfb814",
         sha_linux = "24a786666e6f48ed3c3944b44df5cf146c45cf4faece4cb2686312a3d052a00c",
+        sha_linux_arm64 = "48e670501d215ac5b6b2680c900c517d9028dbc4de43be5dd6f25211a3640f2b",
         sha_mac = "8503fe87dd2f30abff2550e9d6eb8aadeaf30fd3c6972d635b31e67f82e155f7",
         sha_mac_arm64 = "995c7b3c84458edf6b8945e81405320c64a25dfe79eaa427fc1fe9a680f56b4f",
         sha_win = "3839e0a581ae7b19156f004762a8221585e9a0d6237e468b13a878d1947636c5",
@@ -96,6 +109,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.68": struct(
         hash = "b52d8c9150dc7d4c8e4a7a08c7a9b4006c9abe49",
         sha_linux = "1f2bcb47d85eb31d90fa797b3513221adc50f0656bb37f0962a40fd0f49fcf6a",
+        sha_linux_arm64 = "de346e7a489aa27a442215945d154d58a0d35c608b6150b2992af0e70c04e1c5",
         sha_mac = "b180711544d783121370d2c894703f99d370a864ab147730f82fd59b88fa3481",
         sha_mac_arm64 = "5e9b6242b56edc8cb404cbaf6c8bd7eb1f0f168b55b580bd92652f98c5d286f4",
         sha_win = "824d37e8a0845f44e4c1111e8365640eea28944f1bdbd1e9e3fea0279b68baea",
@@ -103,6 +117,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.67": struct(
         hash = "4ae62984ea36ef0e5bfcbd0ed9b62f04bee6426a",
         sha_linux = "535b64822916c80124363a5c7a5bd0cafd703f166d5155c0ad0e464e4a879091",
+        sha_linux_arm64 = "04c5f959702d8c1e5c000752b562271c224dee593e81144280840fed06e36cd9",
         sha_mac = "692b8fdc79a47332ba9881966c72517eedf15b2da7bed37a535dfec55e6bbd9c",
         sha_mac_arm64 = "ac26753f59fa9c8e92be9c91666014ad9400c91fbd37064105d1b5fcae503985",
         sha_win = "8c6af8046ed47386018e42d18b53f57fad0926306dd4315d7f09dfae844b3dd3",
@@ -110,6 +125,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.66": struct(
         hash = "243eae09cf5c20c4fde51a620b92f483255c8214",
         sha_linux = "b10eac37c978b28da2f1f34cdd8a7759c0ed5e5a2d8eb4f4e6790209de33dbf7",
+        sha_linux_arm64 = "9c78a470f74c24fc1fde2c8d86583ed98847b6cbdd87cd0b36ff2d6b4799d950",
         sha_mac = "64fd0603ccbf949967cb0dfd8f1b0b25e018abf8bfe813b53596c4fc78751027",
         sha_mac_arm64 = "fd6250f25101957f56086d292263379880c4b3329819a021008b2058f92ef67b",
         sha_win = "b24f65a1a1111d8ace6ba47b55e07681cd0620f7bf711d1018ee262c9501defc",
@@ -117,6 +133,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.65": struct(
         hash = "fdcf56c75a1d27fdff6525a7e03423595485ca19",
         sha_linux = "b2b7de13d37c4c5126e6c6a077e6019ebacc78ef1fb1b35b9035f03975f5ffaa",
+        sha_linux_arm64 = "f838af6495408f3c0a14d233171b4919b62e445c62805a22dea1875cb709a116",
         sha_mac = "cc50b829a21a041979e0941cfd2047d30a06e3c4a8fd9f662ecdc12a0ab40535",
         sha_mac_arm64 = "db4430db6a085d6ed5284917e632541dad3ce0a9464659fb674055247ad059d0",
         sha_win = "e72ae4ec3231d9a492eadbf77ff28c13efd90307a69df04234792e67a001d05e",
@@ -124,6 +141,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.64": struct(
         hash = "fd61bacaf40131f74987e649a135f1dd559aff60",
         sha_linux = "c39de24beca60fd580f6dff0eca0e275016042a30234588b19eda82397e299f3",
+        sha_linux_arm64 = "61b412135630a60c5517278dc83930e06f80fa286fcc2bb6366c4f620c86e4e0",
         sha_mac = "2644772be398c8095621b3d0fe9ff2d122b18b7b0963c0eb702639d94dfb8e90",
         sha_mac_arm64 = "47449057c345a09aa8750be1a357c364ffea9f8a066066cb341a7a2a14bac96a",
         sha_win = "eb5b59afb420915daab4c383e5f73d456cc14776dce02fdc852c46522cda5531",
@@ -131,6 +149,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.63": struct(
         hash = "aeb36a44b29e8ca9f4c7efbb4735b69003ac2bb9",
         sha_linux = "2a38ac1ea2fe3b7169879f0f666ea278f344cbb5db6e34421b9554939559109c",
+        sha_linux_arm64 = "f1dd5fe4cd22e89b1f5bfd216f1245f9f40f6ea76651a7f66e925a68ff6f18b8",
         sha_mac = "7e192b84aecfade22817b5b38f0c69d1f795a9b990308188d39ed1d218692cd3",
         sha_mac_arm64 = "751ef26a3682f5f23dfdc1c2f80cd0604a32cad61e6373c823de774722ecb9af",
         sha_win = "947f8e867e781750d374d659644897f2345a133ad3d0f9ade23afcb81eeaddd3",
@@ -138,6 +157,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.62": struct(
         hash = "d52176ac8e07c47c1773bb2776ebd91e3886c3af",
         sha_linux = "fd303a2b2a85c4b3ab8aa29595d70c5fde9df71c5254d56ed19d54e9ee98e881",
+        sha_linux_arm64 = "233c0df77644472cd322b45b2d7cf709e6c338799b46f6ec5d5f39ca4dbe8aef",
         sha_mac = "d9cfef7ba8f44bf21be715244d0d5f909f1ccc2a481a301b3c01d12d1babc049",
         sha_mac_arm64 = "de5484d60c858aaa8b93ba6485924adffe734cf4f8296765c089900cf9ce0701",
         sha_win = "7455680bf9c19a26fe4868111ac01401023b0f92e862d3cabadf7950b87707fd",
@@ -145,6 +165,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.61": struct(
         hash = "28e4a74b579b4157bda5fc34f23c7d3905a8bd6c",
         sha_linux = "e3e20e09219fd47a0019bb3252e17db4a00ded39b39b41634bc73f840a8ff2be",
+        sha_linux_arm64 = "a6b858601ca09fb7bb6ddf1a5ffb1a4130454c936ad046d45fef183037828c46",
         sha_mac = "1fe69a3c42fb2857b80c8e77bfab780cb212ed7cf81ae57c0c4d235504df5269",
         sha_mac_arm64 = "4ba702eea409e2d4bfabc73a68919217d3993e7585d95734e3e40a3c9ce1bd21",
         sha_win = "bbafba849ff072a61dd34a8ffc0c85eed20a417854a3ca751b092e3565a92581",
@@ -152,6 +173,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.60": struct(
         hash = "87709b5747de5b1993fe314285528bf4b65c23e1",
         sha_linux = "ff5eb062165920c7cb69935d396f13e9f8ca5b13f2d7f3af2759bcacb5e877e2",
+        sha_linux_arm64 = "2c291942df4868d3f65b31dd964bda9736bfddcd6a7886158963f797d1b45cf5",
         sha_mac = "45586fab1bad65a4293ea8939dafb5ec711ba92ae7b4d1edbaae3b4486f398b5",
         sha_mac_arm64 = "8dc27416a378ad07285d380f68717cfe0db1ea6252fdb1ad012af95e4d3f342e",
         sha_win = "f3147ef2d4ca48ea2624039969fd0529d0bacb63bf49ee4809c681902768b973",
@@ -159,6 +181,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.59": struct(
         hash = "e20ee09a8a740544c4bc6de5d4ba5f81f74b74d6",
         sha_linux = "ae59d1946cb92e1651cbb904fe824b3f07b39f42fa25f582116b5aaa226fa239",
+        sha_linux_arm64 = "25b918d6d5ee2af7ef6b28e089dc21d2dc419dca76c8079bb638cb20459eb9e5",
         sha_mac = "af175bd559cb80459749e504da314af0163291f195461bf4d376d6980c4c60c3",
         sha_mac_arm64 = "e17553bca5d00b30c920595e785281627e973f9e7e14c5dc0a73c355ccafe113",
         sha_win = "bb54256fc3b7824cb75d5474f887d9bf8e1e63c15b351bdfbed898aa293ee4ab",
@@ -166,6 +189,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.58": struct(
         hash = "a4d4afb626c5010f6ccda4638b8d77579a63782e",
         sha_linux = "b188249ecb939dadc679aaf2d3d9afd0fe19ab942f91b7bc926b4f252915dd1a",
+        sha_linux_arm64 = "4aedc8ca641b40d9bd82d85b1dc3458fe1afc9a132da06a09384a5f89c058969",
         sha_mac = "2092aa4bef3b9f88d3f343b042a417ba617d4e04454656d8f2e101ba53f854e8",
         sha_mac_arm64 = "7a9a15845257629b7602d15bdf7633a8e10472b0fa9b3d9ee7149938aa2f2039",
         sha_win = "9fe76b6189566d56f0cf9aecbd23a006778530aa87184a900f5662e39ce7272a",
@@ -173,6 +197,7 @@ EMSCRIPTEN_TAGS = {
     "3.1.57": struct(
         hash = "523b29e1b99a61069a2fa9f9d3cc9be1c4c53d4d",
         sha_linux = "5bc444132258d4404d396f2044a4a334064ad0f1022555cad5ec72804a98ba5a",
+        sha_linux_arm64 = "f0022413afcc1610deff10921b3f5938bf4d01eba46ce96655f2295bdd84bd6a",
         sha_mac = "31ddccb68c86f0a45332982938c49505158860ed4f7e8ccef72a48382e0e3c96",
         sha_mac_arm64 = "cc5fdb65b339464f99b9c731cc63c233ec9577268886a856fa49f227ca2a56d1",
         sha_win = "b53555420bb9b6e31c153e4c59427000ec692be17ae900f659a9b774d1ecebed",

bazel/test_external/MODULE.bazel

@@ -1 +1,6 @@
-bazel_dep(name = "platforms", version = "0.0.9")
+bazel_dep(name = "rules_cc", version = "0.1.1")
+bazel_dep(name = "emsdk")
+local_path_override(
+    module_name = "emsdk",
+    path = "..",
+)

bazel/test_external/WORKSPACE

@@ -1,16 +0,0 @@
-local_repository(
-    name = "emsdk",
-    path = "..",
-)
-
-load("@emsdk//:deps.bzl", "deps")
-
-deps()
-
-load("@emsdk//:emscripten_deps.bzl", "emscripten_deps")
-
-emscripten_deps()
-
-load("@emsdk//:toolchains.bzl", "register_emscripten_toolchains")
-
-register_emscripten_toolchains()

bazel/test_secondary_lto_cache/MODULE.bazel

@@ -1 +1,25 @@
-bazel_dep(name = "platforms", version = "0.0.9")
+bazel_dep(name = "rules_cc", version = "0.1.1")
+bazel_dep(name = "emsdk")
+local_path_override(
+    module_name = "emsdk",
+    path = "..",
+)
+
+emscripten_cache = use_extension(
+    "@emsdk//:emscripten_cache.bzl",
+    "emscripten_cache",
+)
+emscripten_cache.configuration(flags = ["--lto"])
+emscripten_cache.targets(targets = [
+    "crtbegin",
+    "libprintf_long_double-debug",
+    "libstubs-debug",
+    "libnoexit",
+    "libc-debug",
+    "libdlmalloc",
+    "libcompiler_rt",
+    "libc++-noexcept",
+    "libc++abi-debug-noexcept",
+    "libsockets",
+    "libdlmalloc-debug",
+])

bazel/test_secondary_lto_cache/WORKSPACE

@@ -1,31 +0,0 @@
-local_repository(
-    name = "emsdk",
-    path = "..",
-)
-
-load("@emsdk//:deps.bzl", "deps")
-
-deps()
-
-load("@emsdk//:emscripten_deps.bzl", "emscripten_deps")
-
-emscripten_deps()
-
-load("@emsdk//:toolchains.bzl", "register_emscripten_toolchains")
-
-register_emscripten_toolchains(cache = {
-    "configuration": ["--lto"],
-    "targets": [
-        "crtbegin",
-        "libprintf_long_double-debug",
-        "libstubs-debug",
-        "libnoexit",
-        "libc-debug",
-        "libdlmalloc",
-        "libcompiler_rt",
-        "libc++-noexcept",
-        "libc++abi-debug-noexcept",
-        "libsockets",
-        "libdlmalloc-debug"
-    ]
-})

scripts/update_bazel_workspace.py

@@ -8,6 +8,7 @@
 import hashlib
 import json
 import os
+import re
 import requests
 import sys
 
@@ -16,6 +17,7 @@ STORAGE_URL = 'https://storage.googleapis.com/webassembly/emscripten-releases-bu
 EMSDK_ROOT = os.path.dirname(os.path.dirname(__file__))
 RELEASES_TAGS_FILE = EMSDK_ROOT + '/emscripten-releases-tags.json'
 BAZEL_REVISIONS_FILE = EMSDK_ROOT + '/bazel/revisions.bzl'
+BAZEL_MODULE_FILE = EMSDK_ROOT + '/bazel/MODULE.bazel'
 
 
 def get_latest_info():
@@ -40,6 +42,7 @@ def revisions_item(version, latest_hash):
     "{version}": struct(
         hash = "{latest_hash}",
         sha_linux = "{get_sha('linux', 'tar.xz', latest_hash)}",
+        sha_linux_arm64 = "{get_sha('linux', 'tar.xz', latest_hash, '-arm64')}",
         sha_mac = "{get_sha('mac', 'tar.xz', latest_hash)}",
         sha_mac_arm64 = "{get_sha('mac', 'tar.xz', latest_hash, '-arm64')}",
         sha_win = "{get_sha('win', 'zip', latest_hash)}",
@@ -57,8 +60,22 @@ def insert_revision(item):
         f.write(''.join(lines))
 
 
+def update_module_version(version):
+    with open(BAZEL_MODULE_FILE, 'r') as f:
+        content = f.read()
+
+    content = re.sub(
+        r'module\(name = "emsdk", version = "\d+.\d+.\d+"\)',
+        f'module(name = "emsdk", version = "{version}")',
+        content)
+
+    with open(BAZEL_MODULE_FILE, 'w') as f:
+        f.write(content)
+
+
 def main(argv):
     version, latest_hash = get_latest_info()
+    update_module_version(version)
     item = revisions_item(version, latest_hash)
     print('inserting item:')
     print(item)

test/test_bazel.sh

@@ -16,22 +16,21 @@ FAILMSG="!!! scripts/update_bazel_workspace.py needs to be run !!!"
 # Ensure the WORKSPACE file is up to date with the latest version.
 grep ${VER} bazel/revisions.bzl || (echo ${FAILMSG} && false)
 grep ${HASH} bazel/revisions.bzl || (echo ${FAILMSG} && false)
-
+grep ${VER} bazel/MODULE.bazel || (echo ${FAILMSG} && false)
-BAZEL_CMD=$(which bazel || which bazel-7.4.1)
 
 cd bazel
-$BAZEL_CMD build //hello-world:hello-world-wasm
+bazel build //hello-world:hello-world-wasm
-$BAZEL_CMD build //hello-world:hello-world-wasm-simd
+bazel build //hello-world:hello-world-wasm-simd
 
 cd test_external
-$BAZEL_CMD build //:hello-world-wasm
+bazel build //:hello-world-wasm
-$BAZEL_CMD build //long_command_line:long_command_line_wasm
+bazel build //long_command_line:long_command_line_wasm
-$BAZEL_CMD build //:hello-embind-wasm --compilation_mode dbg # debug
+bazel build //:hello-embind-wasm --compilation_mode dbg # debug
 
 # Test use of the closure compiler
-$BAZEL_CMD build //:hello-embind-wasm --compilation_mode opt # release
+bazel build //:hello-embind-wasm --compilation_mode opt # release
 # This function should not be minified if the externs file is loaded correctly.
 grep "customJSFunctionToTestClosure" bazel-bin/hello-embind-wasm/hello-embind.js
 
 cd ../test_secondary_lto_cache
-$BAZEL_CMD build //:hello-world-wasm
+bazel build //:hello-world-wasm

test/test_bazel_mac.sh

@@ -16,6 +16,7 @@ FAILMSG="!!! scripts/update_bazel_workspace.py needs to be run !!!"
 # Ensure the WORKSPACE file is up to date with the latest version.
 grep ${VER} bazel/revisions.bzl || (echo ${FAILMSG} && false)
 grep ${HASH} bazel/revisions.bzl || (echo ${FAILMSG} && false)
+grep ${VER} bazel/MODULE.bazel || (echo ${FAILMSG} && false)
 
 cd bazel
 bazel build //hello-world:hello-world-wasm