Bazel Windows Support (#929)

bazel/emscripten_toolchain/BUILD.bazel

@@ -6,9 +6,12 @@ filegroup(
     name = "common-script-includes",
     srcs = [
         "emar.sh",
+        "emar.bat",
         "emcc.sh",
+        "emcc.bat",
         "emscripten_config",
         "env.sh",
+        "env.bat",
         "@emsdk//:binaries",
         "@emsdk//:node_modules",
         "@nodejs//:node_files",
@@ -24,6 +27,7 @@ filegroup(
     name = "link-emscripten",
     srcs = [
         "emcc_link.sh",
+        "emcc_link.bat",
         "link_wrapper.py",
         ":common-script-includes",
         "@emsdk//:binaries",
@@ -51,6 +55,10 @@ emscripten_cc_toolchain_config_rule(
     cpu = "wasm",
     em_config = "emscripten_config",
     emscripten_binaries = "@emsdk//:binaries",
+    script_extension = select({
+        "@bazel_tools//src/conditions:host_windows": "bat",
+        "//conditions:default": "sh",
+    }),
 )
 
 cc_toolchain(

bazel/emscripten_toolchain/crosstool.bzl

@@ -74,23 +74,27 @@ def _impl(ctx):
 
     builtin_sysroot = emscripten_dir + "/emscripten/cache/sysroot"
 
+    emcc_script = "emcc.%s" % ctx.attr.script_extension
+    emcc_link_script = "emcc_link.%s" % ctx.attr.script_extension
+    emar_script = "emar.%s" % ctx.attr.script_extension
+
     ################################################################
     # Tools
     ################################################################
-    clang_tool = tool(path = "emcc.sh")
+    clang_tool = tool(path = emcc_script)
     clif_match_tool = tool(path = "dummy_clif_matcher")
-    link_tool = tool(path = "emcc_link.sh")
-    archive_tool = tool(path = "emar.sh")
+    link_tool = tool(path = emcc_link_script)
+    archive_tool = tool(path = emar_script)
     strip_tool = tool(path = "NOT_USED_STRIP_TOOL")
 
     #### Legacy tool paths (much of this is redundant with action_configs, but
     #### these are still used for some things)
     tool_paths = [
-        tool_path(name = "ar", path = "emar.sh"),
+        tool_path(name = "ar", path = emar_script),
         tool_path(name = "cpp", path = "/bin/false"),
-        tool_path(name = "gcc", path = "emcc.sh"),
+        tool_path(name = "gcc", path = emcc_script),
         tool_path(name = "gcov", path = "/bin/false"),
-        tool_path(name = "ld", path = "emcc_link.sh"),
+        tool_path(name = "ld", path = emcc_link_script),
         tool_path(name = "nm", path = "NOT_USED"),
         tool_path(name = "objdump", path = "/bin/false"),
         tool_path(name = "strip", path = "NOT_USED"),
@@ -1106,6 +1110,7 @@ emscripten_cc_toolchain_config_rule = rule(
         "cpu": attr.string(mandatory = True, values = ["asmjs", "wasm"]),
         "em_config": attr.label(mandatory = True, allow_single_file = True),
         "emscripten_binaries": attr.label(mandatory = True),
+        "script_extension": attr.string(mandatory = True, values = ["sh", "bat"]),
     },
     provides = [CcToolchainConfigInfo],
 )

bazel/emscripten_toolchain/emar.bat

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

bazel/emscripten_toolchain/emcc.bat

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

bazel/emscripten_toolchain/emcc_link.bat

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

bazel/emscripten_toolchain/emscripten_config

@@ -8,5 +8,5 @@ LLVM_ROOT = BINARYEN_ROOT + "/bin"
 FROZEN_CACHE = True
 
 system = platform.system()
-nodejs_binary = "node.exe" if(system =="Windows") else "bin/node"
+nodejs_binary = "bin/nodejs/node.exe" if(system =="Windows") else "bin/node"
 NODE_JS = ROOT_DIR + "/external/nodejs_{}_amd64/{}".format(system.lower(), nodejs_binary)

bazel/emscripten_toolchain/env.bat

@@ -0,0 +1,5 @@
+@ECHO OFF
+
+set ROOT_DIR=%CD%
+set EMSCRIPTEN=%ROOT_DIR%\%EM_BIN_PATH%\emscripten
+set EM_CONFIG=%ROOT_DIR%\%EM_CONFIG_PATH%

bazel/emscripten_toolchain/link_wrapper.py

@@ -39,7 +39,7 @@ if any(' ' in a for a in param_file_args):
   sys.argv[1] = '@' + new_param_filename
 
 emcc_py = os.path.join(os.environ['EMSCRIPTEN'], 'emcc.py')
-rtn = subprocess.call(['python3', emcc_py] + sys.argv[1:])
+rtn = subprocess.call([sys.executable, emcc_py] + sys.argv[1:])
 if rtn != 0:
   sys.exit(1)
 

bazel/emscripten_toolchain/wasm_binary.py

@@ -20,7 +20,7 @@ WebAssembly binary into a larger web application.
 
 import argparse
 import os
-import subprocess
+import tarfile
 
 
 def ensure(f):
@@ -40,12 +40,14 @@ def main():
   parser.add_argument('--output_path', help='The path to extract into.')
   args = parser.parse_args()
 
+  args.archive = os.path.normpath(args.archive)
+
   basename = os.path.basename(args.archive)
   stem = basename.split('.')[0]
 
   # Extract all files from the tarball.
-  subprocess.check_call(
-      ['tar', 'xf', args.archive, '-C', args.output_path])
+  tar = tarfile.open(args.archive)
+  tar.extractall(args.output_path)
 
   # At least one of these two files should exist at this point.
   ensure(os.path.join(args.output_path, stem + '.js'))

bazel/emscripten_toolchain/wasm_cc_binary.bzl

@@ -55,15 +55,10 @@ _wasm_transition = transition(
 )
 
 def _wasm_binary_impl(ctx):
-    cc_target = ctx.attr.cc_target[0]
+    args = ctx.actions.args()
+    args.add("--output_path", ctx.outputs.loader.dirname)
+    args.add_all("--archive", ctx.files.cc_target)
 
-    args = [
-        "--output_path={}".format(ctx.outputs.loader.dirname),
-    ] + [
-        ctx.expand_location("--archive=$(location {})".format(
-            cc_target.label,
-        ), [cc_target]),
-    ]
     outputs = [
         ctx.outputs.loader,
         ctx.outputs.wasm,
@@ -80,7 +75,7 @@ def _wasm_binary_impl(ctx):
     ctx.actions.run(
         inputs = ctx.files.cc_target,
         outputs = outputs,
-        arguments = args,
+        arguments = [args],
         executable = ctx.executable._wasm_binary_extractor,
     )