[native_toolchain_c] Support Clang on Windows

pkgs/native_toolchain_c/lib/src/cbuilder/run_cbuilder.dart

@@ -224,6 +224,8 @@ class RunCBuilder {
               '${targetAndroidNdkApi!}',
           '--sysroot=${androidSysroot(toolInstance).toFilePath()}',
         ],
+        if (codeConfig.targetOS == OS.windows)
+          '--target=${clangWindowsTargetFlags[architecture]!}',
         if (codeConfig.targetOS == OS.macOS)
           '--target=${appleClangMacosTargetFlags[architecture]!}',
         if (codeConfig.targetOS == OS.iOS)
@@ -244,7 +246,8 @@ class RunCBuilder {
           installName!.toFilePath(),
         ],
         if (pic != null)
-          if (toolInstance.tool.isClangLike) ...[
+          if (toolInstance.tool.isClangLike &&
+              codeConfig.targetOS != OS.windows) ...[
             if (pic!) ...[
               if (dynamicLibrary != null) '-fPIC',
               // Using PIC for static libraries allows them to be linked into
@@ -419,6 +422,12 @@ class RunCBuilder {
     },
   };
 
+  static const clangWindowsTargetFlags = {
+    Architecture.arm64: 'arm64-pc-windows-msvc',
+    Architecture.ia32: 'i386-pc-windows-msvc',
+    Architecture.x64: 'x86_64-pc-windows-msvc',
+  };
+
   static const defaultCppLinkStdLib = {
     OS.android: 'c++_shared',
     OS.fuchsia: 'c++',

pkgs/native_toolchain_c/lib/src/native_toolchain/clang.dart

@@ -2,8 +2,11 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:native_assets_cli/code_assets.dart';
+
 import '../tool/tool.dart';
 import '../tool/tool_resolver.dart';
+import 'msvc.dart';
 
 /// The Clang compiler.
 ///
@@ -14,10 +17,23 @@ final Tool clang = Tool(
     wrappedResolver: CliFilter(
       cliArguments: ['--version'],
       keepIf: ({required String stdout}) => !stdout.contains('Apple clang'),
-      wrappedResolver: PathToolResolver(
-        toolName: 'Clang',
-        executableName: 'clang',
-      ),
+      wrappedResolver: ToolResolvers([
+        PathToolResolver(
+          toolName: 'Clang',
+          executableName: OS.current.executableFileName('clang'),
+        ),
+        RelativeToolResolver(
+          toolName: 'Clang',
+          wrappedResolver: visualStudio.defaultResolver!,
+          relativePath: Uri(path: './VC/Tools/Llvm/bin/clang.exe'),
+        ),
+        InstallLocationResolver(
+          toolName: 'Clang',
+          paths: [
+            'C:/Program Files/LLVM/bin/clang.exe',
+          ],
+        ),
+      ]),
     ),
   ),
 );
@@ -32,7 +48,7 @@ final Tool llvmAr = Tool(
       RelativeToolResolver(
         toolName: 'LLVM archiver',
         wrappedResolver: clang.defaultResolver!,
-        relativePath: Uri.file('llvm-ar'),
+        relativePath: Uri.file(OS.current.executableFileName('llvm-ar')),
       ),
     ]),
   ),
@@ -48,7 +64,7 @@ final Tool lld = Tool(
       RelativeToolResolver(
         toolName: 'LLD',
         wrappedResolver: clang.defaultResolver!,
-        relativePath: Uri.file('ld.lld'),
+        relativePath: Uri.file(OS.current.executableFileName('ld.lld')),
       ),
     ]),
   ),

pkgs/native_toolchain_c/test/cbuilder/cbuilder_cross_windows_host_test.dart

@@ -11,19 +11,36 @@ library;
 import 'dart:io';
 
 import 'package:native_toolchain_c/native_toolchain_c.dart';
+import 'package:native_toolchain_c/src/native_toolchain/clang.dart';
 import 'package:native_toolchain_c/src/native_toolchain/msvc.dart';
 import 'package:native_toolchain_c/src/utils/run_process.dart';
 import 'package:test/test.dart';
 
 import '../helpers.dart';
 
-void main() {
+void main() async {
   if (!Platform.isWindows) {
     // Avoid needing status files on Dart SDK CI.
     return;
   }
 
+  final compilers = {
+    // Either provided to be MSVC or null which defaults to MSVC.
+    msvc: () async => cCompiler,
+    // Clang on Windows.
+    clang: () async => CCompilerConfig(
+          archiver:
+              (await llvmAr.defaultResolver!.resolve(logger: logger)).first.uri,
+          compiler:
+              (await clang.defaultResolver!.resolve(logger: logger)).first.uri,
+          linker:
+              (await lld.defaultResolver!.resolve(logger: logger)).first.uri,
+        )
+  };
+
   const targets = [
+    // TODO(/~https://github.com/dart-lang/native/issues/170): Support arm64.
+    // Architecture.arm64,
     Architecture.ia32,
     Architecture.x64,
   ];
@@ -36,86 +53,95 @@ void main() {
   });
 
   const dumpbinMachine = {
+    Architecture.arm64: 'ARM64',
     Architecture.ia32: 'x86',
     Architecture.x64: 'x64',
   };
 
   const optimizationLevels = OptimizationLevel.values;
   var selectOptimizationLevel = 0;
+  var selectBuildMode = 0;
 
   final dumpbinFileType = {
     DynamicLoadingBundled(): 'DLL',
     StaticLinking(): 'LIBRARY',
   };
 
-  for (final linkMode in [DynamicLoadingBundled(), StaticLinking()]) {
-    for (final target in targets) {
-      // Cycle through all optimization levels.
-      final optimizationLevel = optimizationLevels[selectOptimizationLevel];
-      selectOptimizationLevel =
-          (selectOptimizationLevel + 1) % optimizationLevels.length;
-      test('CBuilder $linkMode library $target $optimizationLevel', () async {
-        final tempUri = await tempDirForTest();
-        final tempUri2 = await tempDirForTest();
-        final addCUri =
-            packageUri.resolve('test/cbuilder/testfiles/add/src/add.c');
-        const name = 'add';
-
-        final buildInputBuilder = BuildInputBuilder()
-          ..setupShared(
-            packageName: name,
-            packageRoot: tempUri,
-            outputFile: tempUri.resolve('output.json'),
-            outputDirectory: tempUri,
-            outputDirectoryShared: tempUri2,
-          )
-          ..config.setupBuild(
-            linkingEnabled: false,
-            dryRun: false,
-          )
-          ..config.setupShared(buildAssetTypes: [CodeAsset.type])
-          ..config.setupCode(
-            targetOS: OS.windows,
-            targetArchitecture: target,
-            linkModePreference: linkMode == DynamicLoadingBundled()
-                ? LinkModePreference.dynamic
-                : LinkModePreference.static,
-            cCompiler: cCompiler,
+  for (final compiler in compilers.keys) {
+    for (final linkMode in [DynamicLoadingBundled(), StaticLinking()]) {
+      for (final target in targets) {
+        // Cycle through all optimization levels.
+        final optimizationLevel = optimizationLevels[selectOptimizationLevel];
+        selectOptimizationLevel =
+            (selectOptimizationLevel + 1) % optimizationLevels.length;
+        final buildMode = BuildMode.values[selectBuildMode];
+        selectBuildMode = (selectBuildMode + 1) % BuildMode.values.length;
+        test(
+            'CBuilder ${compiler.name} $linkMode library $target'
+            ' $optimizationLevel $buildMode', () async {
+          final tempUri = await tempDirForTest();
+          final tempUri2 = await tempDirForTest();
+          final addCUri =
+              packageUri.resolve('test/cbuilder/testfiles/add/src/add.c');
+          const name = 'add';
+
+          final buildInputBuilder = BuildInputBuilder()
+            ..setupShared(
+              packageName: name,
+              packageRoot: tempUri,
+              outputFile: tempUri.resolve('output.json'),
+              outputDirectory: tempUri,
+              outputDirectoryShared: tempUri2,
+            )
+            ..config.setupBuild(
+              linkingEnabled: false,
+              dryRun: false,
+            )
+            ..config.setupShared(buildAssetTypes: [CodeAsset.type])
+            ..config.setupCode(
+              targetOS: OS.windows,
+              targetArchitecture: target,
+              linkModePreference: linkMode == DynamicLoadingBundled()
+                  ? LinkModePreference.dynamic
+                  : LinkModePreference.static,
+              cCompiler: await (compilers[compiler]!)(),
+            );
+
+          final buildInput = BuildInput(buildInputBuilder.json);
+          final buildOutput = BuildOutputBuilder();
+
+          final cbuilder = CBuilder.library(
+            name: name,
+            assetName: name,
+            sources: [addCUri.toFilePath()],
+            optimizationLevel: optimizationLevel,
+            buildMode: buildMode,
+          );
+          await cbuilder.run(
+            input: buildInput,
+            output: buildOutput,
+            logger: logger,
           );
 
-        final buildInput = BuildInput(buildInputBuilder.json);
-        final buildOutput = BuildOutputBuilder();
-
-        final cbuilder = CBuilder.library(
-          name: name,
-          assetName: name,
-          sources: [addCUri.toFilePath()],
-          optimizationLevel: optimizationLevel,
-          buildMode: BuildMode.release,
-        );
-        await cbuilder.run(
-          input: buildInput,
-          output: buildOutput,
-          logger: logger,
-        );
-
-        final libUri =
-            tempUri.resolve(OS.windows.libraryFileName(name, linkMode));
-        expect(await File.fromUri(libUri).exists(), true);
-        final result = await runProcess(
-          executable: dumpbinUri,
-          arguments: ['/HEADERS', libUri.toFilePath()],
-          logger: logger,
-        );
-        expect(result.exitCode, 0);
-        final machine =
-            result.stdout.split('\n').firstWhere((e) => e.contains('machine'));
-        expect(machine, contains(dumpbinMachine[target]));
-        final fileType = result.stdout
-            .split('\n')
-            .firstWhere((e) => e.contains('File Type'));
-        expect(fileType, contains(dumpbinFileType[linkMode]));
-      });
+          final libUri =
+              tempUri.resolve(OS.windows.libraryFileName(name, linkMode));
+          expect(await File.fromUri(libUri).exists(), true);
+          final result = await runProcess(
+            executable: dumpbinUri,
+            arguments: ['/HEADERS', libUri.toFilePath()],
+            logger: logger,
+          );
+          expect(result.exitCode, 0);
+          final machine = result.stdout
+              .split('\n')
+              .firstWhere((e) => e.contains('machine'));
+          expect(machine, contains(dumpbinMachine[target]));
+          final fileType = result.stdout
+              .split('\n')
+              .firstWhere((e) => e.contains('File Type'));
+          expect(fileType, contains(dumpbinFileType[linkMode]));
+        });
+      }
     }
   }
 }

pkgs/native_toolchain_c/test/cbuilder/testfiles/add/src/add.c

@@ -6,6 +6,10 @@
 
 #ifdef DEBUG
 #include <stdio.h>
+
+#if _WIN32
+#include <wchar.h>
+#endif
 #endif
 
 #if _WIN32
@@ -17,6 +21,9 @@
 FFI_EXPORT int32_t add(int32_t a, int32_t b) {
 #ifdef DEBUG
   printf("Adding %i and %i.\n", a, b);
+#if _WIN32
+  wprintf("Adding %i and %i.\n", a, b);
+#endif
 #endif
   return a + b;
 }

pkgs/native_toolchain_c/test/native_toolchain/clang_test.dart

@@ -16,7 +16,11 @@ import 'package:test/test.dart';
 import '../helpers.dart';
 
 void main() {
-  if (!Platform.isLinux) {
+  if (Platform.isMacOS ||
+      (Platform.isWindows &&
+          Platform.environment['DART_HOOK_TESTING_C_COMPILER__CC']
+                  ?.endsWith('cl.exe') ==
+              true)) {
     // Avoid needing status files on Dart SDK CI.
     return;
   }