Proof of concept for emcmake toolchain registration

INCOMPLETE, see proxy-wasm/proxy-wasm-cpp-sdk#157

Signed-off-by: Martijn Stevenson <[email protected]>

bazel/emscripten_deps.bzl

@@ -167,38 +167,3 @@ def emscripten_deps(emscripten_version = "latest"):
             build_file_content = BUILD_FILE_CONTENT_TEMPLATE.format(bin_extension = ".exe"),
             type = "zip",
         )
-
-    if "emscripten_npm_linux" not in excludes:
-        npm_install(
-            name = "emscripten_npm_linux",
-            package_json = "@emscripten_bin_linux//:emscripten/package.json",
-            package_lock_json = "@emscripten_bin_linux//:emscripten/package-lock.json",
-        )
-
-    if "emscripten_npm_linux_arm64" not in excludes:
-        npm_install(
-            name = "emscripten_npm_linux_arm64",
-            package_json = "@emscripten_bin_linux_arm64//:emscripten/package.json",
-            package_lock_json = "@emscripten_bin_linux_arm64//:emscripten/package-lock.json",
-        )
-
-    if "emscripten_npm_mac" not in excludes:
-        npm_install(
-            name = "emscripten_npm_mac",
-            package_json = "@emscripten_bin_mac//:emscripten/package.json",
-            package_lock_json = "@emscripten_bin_mac//:emscripten/package-lock.json",
-        )
-
-    if "emscripten_npm_mac_arm64" not in excludes:
-        npm_install(
-            name = "emscripten_npm_mac",
-            package_json = "@emscripten_bin_mac_arm64//:emscripten/package.json",
-            package_lock_json = "@emscripten_bin_mac_arm64//:emscripten/package-lock.json",
-        )
-
-    if "emscripten_npm_win" not in excludes:
-        npm_install(
-            name = "emscripten_npm_win",
-            package_json = "@emscripten_bin_win//:emscripten/package.json",
-            package_lock_json = "@emscripten_bin_win//:emscripten/package-lock.json",
-        )

bazel/emscripten_toolchain/BUILD.bazel

@@ -1,44 +1,54 @@
 load(":toolchain.bzl", "emscripten_cc_toolchain_config_rule")
+load("@rules_foreign_cc//toolchains/native_tools:native_tools_toolchain.bzl", "native_tool_toolchain")
 
 package(default_visibility = ["//visibility:public"])
 
 filegroup(
     name = "common_files",
     srcs = [
         "emscripten_config",
-        "env.sh",
         "env.bat",
+        "env.sh",
         "@nodejs//:node_files",
     ],
 )
 
 filegroup(
     name = "compiler_files",
     srcs = [
-        "emcc.sh",
         "emcc.bat",
-        "@emsdk//:compiler_files",
+        "emcc.sh",
         ":common_files",
+        "@emsdk//:compiler_files",
     ],
 )
 
 filegroup(
     name = "linker_files",
     srcs = [
-        "emcc_link.sh",
         "emcc_link.bat",
+        "emcc_link.sh",
         "link_wrapper.py",
-        "@emsdk//:linker_files",
         ":common_files",
+        "@emsdk//:linker_files",
     ],
 )
 
 filegroup(
     name = "ar_files",
     srcs = [
-        "emar.sh",
         "emar.bat",
+        "emar.sh",
+        ":common_files",
         "@emsdk//:ar_files",
+    ],
+)
+
+filegroup(
+    name = "cmake_files",
+    srcs = [
+        "emcmake.bat",
+        "emcmake.sh",
         ":common_files",
     ],
 )
@@ -81,13 +91,29 @@ cc_toolchain_suite(
     },
 )
 
+native_tool_toolchain(
+    name = "cmake-compiler-wasm",
+    path = select({
+        "@platforms//os:windows": "$(execpath :cmake_files)/emcmake.bat",
+        "//conditions:default": "$(execpath :cmake_files)/emcmake.sh",
+    }),
+    target = ":cmake_files",
+)
+
 toolchain(
     name = "cc-toolchain-wasm",
     target_compatible_with = ["@platforms//cpu:wasm32"],
     toolchain = ":cc-compiler-wasm",
     toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
 )
 
+toolchain(
+    name = "cmake-toolchain-wasm",
+    target_compatible_with = ["@platforms//cpu:wasm32"],
+    toolchain = ":cmake-compiler-wasm",
+    toolchain_type = "@rules_foreign_cc//toolchains:cmake_toolchain",
+)
+
 py_binary(
     name = "wasm_binary",
     srcs = ["wasm_binary.py"],

bazel/emscripten_toolchain/emcmake.bat

@@ -0,0 +1,5 @@
+@ECHO OFF
+
+call external\emsdk\emscripten_toolchain\env.bat
+
+py -3 %EMSCRIPTEN%\emcmake.py %*

bazel/emscripten_toolchain/emcmake.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+source $(dirname $0)/env.sh
+
+exec python3 $EMSCRIPTEN/emcmake.py "$@"

bazel/toolchains.bzl

@@ -1,2 +1,3 @@
 def register_emscripten_toolchains():
     native.register_toolchains(str(Label("//emscripten_toolchain:cc-toolchain-wasm")))
+    native.register_toolchains(str(Label("//emscripten_toolchain:cmake-toolchain-wasm")))