Drop support for secondary caches on Windows

Author: allsey87

bazel/emscripten_cache.bzl

@@ -3,24 +3,21 @@ package(default_visibility = ['//visibility:public'])
 exports_files(['emscripten_config'])
 """
 
-def get_root_and_binext(repository_ctx):
-    """
-    Retrieve the path to the Emscripten binary directory
+EMBUILDER_FILE_CONTENT_TEMPLATE = """
+CACHE = '{cache}'
+EMSCRIPTEN_ROOT = '{emscripten_root}'
+BINARYEN_ROOT = '{binaryen_root}'
+LLVM_ROOT = '{llvm_root}'
 
-    This function determines the correct Emscripten binary directory path by
-    examining the operating system and architecture of the environment. It 
-    supports Linux, macOS, and Windows operating systems with specific
-    architectures.
+import platform
 
-    Args:
-      repository_ctx: The repository context object which provides information
-        about the OS and architecture, and methods to obtain paths and labels.
-
-    Returns:
-      str: The directory path to the Emscripten binaries for the detected OS
-      and architecture.
+system = platform.system()
+machine = "arm64" if platform.machine() in ('arm64', 'aarch64') else "amd64"
+nodejs_binary = "bin/nodejs/node.exe" if(system =="Windows") else "bin/node"
+NODE_JS = '{external_root}/nodejs_{{}}_{{}}/{{}}'.format(system.lower(), machine, nodejs_binary)
+"""
 
-    """
+def get_root_and_script_ext(repository_ctx):
     if repository_ctx.os.name.startswith('linux'):
         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, '')
@@ -36,7 +33,8 @@ def get_root_and_binext(repository_ctx):
         else:
             fail('Unsupported architecture for MacOS')
     elif repository_ctx.os.name.startswith('windows'):
-        return (repository_ctx.path(Label("@emscripten_bin_win//:BUILD.bazel")).dirname, '.exe')
+        fail('Using a secondary cache is not supported on Windows')
+        #return (repository_ctx.path(Label("@emscripten_bin_win//:BUILD.bazel")).dirname, '.bat')
     else:
         fail('Unsupported operating system')
 
@@ -49,35 +47,40 @@ def _emscripten_cache_impl(repository_ctx):
     )
 
     if repository_ctx.attr.libraries or repository_ctx.attr.flags:
-        root, binext = get_root_and_binext(repository_ctx)
+        root, script_ext = get_root_and_script_ext(repository_ctx)
         llvm_root = root.get_child("bin")
         emscripten_root = root.get_child("emscripten")
-        embuilder_path = emscripten_root.get_child("embuilder")
-        cache_path = repository_ctx.path('cache')
-        nodejs = repository_ctx.path(Label("@nodejs//:BUILD.bazel")).dirname.get_child("bin").get_child("node")
+        cache = repository_ctx.path("cache")
+        # Ugly hack to get the "external" directory (needed for Windows/Node.js)
+        external_root = repository_ctx.path(Label("@nodejs//:BUILD.bazel")).dirname.dirname
         # Create configuration file
-        embuilder_config_content  = "NODE_JS = '{}{}'\n".format(nodejs, binext)
-        embuilder_config_content += "LLVM_ROOT = '{}'\n".format(llvm_root)
-        embuilder_config_content += "BINARYEN_ROOT = '{}'\n".format(root)
-        embuilder_config_content += "EMSCRIPTEN_ROOT = '{}'\n".format(emscripten_root)
-        embuilder_config_content += "CACHE = '{}'\n".format(cache_path)
+        embuilder_config_content = EMBUILDER_FILE_CONTENT_TEMPLATE.format(
+            cache=cache,
+            emscripten_root=emscripten_root,
+            binaryen_root=root,
+            llvm_root=llvm_root,
+            external_root=external_root,
+        )
         repository_ctx.file("embuilder_config", embuilder_config_content)
         embuilder_config_path = repository_ctx.path("embuilder_config")
+        embuilder_path = "{}{}".format(emscripten_root.get_child("embuilder"), script_ext)
         # Prepare the command line
         if repository_ctx.attr.libraries:
             libraries = repository_ctx.attr.libraries
         else:
-            # if no libraries are requested, build everything
+            # If no libraries are requested, build everything
             libraries = ["ALL"]
         flags = ["--em-config", embuilder_config_path] + repository_ctx.attr.flags
         embuilder_args = [embuilder_path] + flags + ["build"] + libraries
         # Run embuilder
         repository_ctx.report_progress("Building secondary cache")
-        result = repository_ctx.execute(embuilder_args, quiet=False)
+        result = repository_ctx.execute(embuilder_args, quiet=True)
         if result.return_code != 0:
+            # Windows fails here because external/nodejs_windows_amd64/bin/nodejs/node.exe
+            # does not exist at this point (while the equivalent on Linux and MacOS does)
             fail("Embuilder exited with a non-zero return code")
         # Override Emscripten's cache with the secondary cache
-        default_config += "CACHE = '{}'\n".format(cache_path)
+        default_config += "CACHE = '{}'\n".format(cache)
 
     # Create the configuration file for the toolchain and export
     repository_ctx.file('emscripten_config', default_config)

test/test_bazel.ps1

@@ -23,8 +23,8 @@ if (-not $?) { Exit $LastExitCode }
 bazel build //:hello-embind-wasm --compilation_mode opt # release
 if (-not $?) { Exit $LastExitCode }
 
-Set-Location ..\test_secondary_lto_cache
+# Set-Location ..\test_secondary_lto_cache
 
-bazel build //:hello-world-wasm
-if (-not $?) { Exit $LastExitCode }
+# bazel build //:hello-world-wasm
+# if (-not $?) { Exit $LastExitCode }