[vm] Support assembly output for Windows.

The resulting DLL lacks debugging information / PDB.

TEST=ci
Bug: #60812
Bug: #60813
Cq-Include-Trybots: luci.dart.try:vm-aot-win-debug-arm64-try,vm-aot-win-debug-x64-try,vm-aot-win-release-arm64-try,vm-aot-win-release-x64-try
Change-Id: I305bad0081ec24f27249ad9b75ff8d32fa9c4893
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/428200
Reviewed-by: Tess Strickland <[email protected]>
Commit-Queue: Ryan Macnak <[email protected]>

Author: rmacnak-google

pkg/test_runner/lib/src/compiler_configuration.dart

@@ -956,14 +956,16 @@ class PrecompilerCompilerConfiguration extends CompilerConfiguration
     }
 
     var format = _configuration.genSnapshotFormat!;
-    var basename = (format == GenSnapshotFormat.assembly) ? 'out.S' : 'out.aotsnapshot';
+    var output = (format == GenSnapshotFormat.assembly)
+        ? tempAssemblyFile(tempDir)
+        : tempAOTFile(tempDir);
     // Whether or not loading units are used. Mach-O doesn't currently support
     // this, and this isn't done for assembly output to avoid having to handle
     // the assembly of multiple assembly output files.
     var split = format == GenSnapshotFormat.elf;
     var args = [
       "--snapshot-kind=${format.snapshotType}",
-      "--${format.fileOption}=$tempDir/$basename",
+      "--${format.fileOption}=$output",
       if (split) "--loading-unit-manifest=$tempDir/ignored.json",
       if (_isAndroid && (_isArm || _isArmX64)) ...[
         '--no-sim-use-hardfp',
@@ -1074,6 +1076,8 @@ class PrecompilerCompilerConfiguration extends CompilerConfiguration
         case Architecture.arm_x64:
           target = ['-arch', 'armv7'];
           break;
+        case Architecture.arm64:
+        case Architecture.arm64c:
         case Architecture.simarm64:
         case Architecture.simarm64c:
           target = ['-arch', 'arm64'];
@@ -1087,6 +1091,25 @@ class PrecompilerCompilerConfiguration extends CompilerConfiguration
           target = ['-arch', 'riscv64'];
           break;
       }
+    } else if (Platform.isWindows) {
+      cc = 'buildtools\\win-x64\\clang\\bin\\clang.exe';
+      shared = '-shared';
+      switch (_configuration.architecture) {
+        case Architecture.x64:
+        case Architecture.x64c:
+        case Architecture.simx64:
+        case Architecture.simx64c:
+          target = ['--target=x86_64-windows'];
+          break;
+        case Architecture.arm64:
+        case Architecture.arm64c:
+        case Architecture.simarm64:
+        case Architecture.simarm64c:
+          target = ['--target=arm64-windows'];
+          break;
+      }
+      ldFlags.add('-nostdlib');
+      ldFlags.add('-Wl,/NOENTRY');
     } else {
       throw "Platform not supported: ${Platform.operatingSystem}";
     }
@@ -1096,8 +1119,8 @@ class PrecompilerCompilerConfiguration extends CompilerConfiguration
       ...ldFlags,
       shared,
       '-o',
-      '$tempDir/out.aotsnapshot',
-      '$tempDir/out.S'
+      tempAOTFile(tempDir),
+      tempAssemblyFile(tempDir),
     ];
 
     return CompilationCommand('assemble', tempDir, bootstrapDependencies(), cc,
@@ -1109,7 +1132,7 @@ class PrecompilerCompilerConfiguration extends CompilerConfiguration
       String tempDir, Map<String, String> environmentOverrides) {
     var stripTool = "$ndkPath/toolchains/llvm/prebuilt/"
         "$host-x86_64/bin/llvm-strip";
-    var args = ['--strip-unneeded', "$tempDir/out.aotsnapshot"];
+    var args = ['--strip-unneeded', tempAOTFile(tempDir)];
     return CompilationCommand('strip', tempDir, bootstrapDependencies(),
         stripTool, args, environmentOverrides,
         alwaysCompile: !_useSdk);
@@ -1124,8 +1147,19 @@ class PrecompilerCompilerConfiguration extends CompilerConfiguration
   /// almost identical configurations are tested simultaneously.
   Command computeRemoveAssemblyCommand(String tempDir, List arguments,
       Map<String, String> environmentOverrides) {
-    return CompilationCommand('remove_assembly', tempDir,
-        bootstrapDependencies(), 'rm', ['$tempDir/out.S'], environmentOverrides,
+    String exec;
+    List<String> args;
+
+    if (Platform.isWindows) {
+      exec = "cmd.exe";
+      args = ["/c", "del", tempAssemblyFile(tempDir)];
+    } else {
+      exec = "rm";
+      args = [tempAssemblyFile(tempDir)];
+    }
+
+    return CompilationCommand("remove_assembly", tempDir,
+        bootstrapDependencies(), exec, args, environmentOverrides,
         alwaysCompile: !_useSdk);
   }
 
@@ -1169,8 +1203,7 @@ class PrecompilerCompilerConfiguration extends CompilerConfiguration
       // directory on the device, use that one instead.
       dir = DartPrecompiledAdbRuntimeConfiguration.deviceTestDir;
     }
-    originalArguments =
-        _replaceDartFiles(originalArguments, "$dir/out.aotsnapshot");
+    originalArguments = _replaceDartFiles(originalArguments, tempAOTFile(dir));
 
     return [
       if (_enableAsserts) '--enable_asserts',
@@ -1373,6 +1406,21 @@ abstract mixin class VMKernelCompilerMixin {
 
   String tempKernelFile(String tempDir) =>
       Path('$tempDir/out.dill').toNativePath();
+  String tempAssemblyFile(String tempDir) =>
+      Path('$tempDir/out.S').toNativePath();
+  String tempAOTFile(String tempDir) {
+    switch (_configuration.system) {
+      case System.android:
+      case System.fuchsia:
+      case System.linux:
+        return Path('$tempDir/libout.so').toNativePath();
+      case System.mac:
+        return Path('$tempDir/libout.dylib').toNativePath();
+      case System.win:
+        return Path('$tempDir/out.dll').toNativePath();
+    }
+    return Path('$tempDir/out.aotsnapshot').toNativePath();
+  }
 
   Command computeCompileToKernelCommand(String tempDir, List<String> arguments,
       Map<String, String> environmentOverrides) {

pkg/vm_service/test/common/test_helper.dart

@@ -35,7 +35,7 @@ Uri _getTestUri(String script) {
     // If running from pub we can assume that we're in the root of the package
     // directory.
     return Uri.parse('test/$script');
-  } else if (io.Platform.script.toFilePath().endsWith('out.aotsnapshot')) {
+  } else if (!io.Platform.script.toFilePath().endsWith('.dart')) {
     // We're running an AOT test. In this case, we need to use the exact URI we
     // launched with.
     return io.Platform.script;

runtime/bin/dartutils.cc

@@ -35,6 +35,7 @@ dart::SimpleHashMap* DartUtils::environment_ = nullptr;
 
 MagicNumberData appjit_magic_number = {8, {0xdc, 0xdc, 0xf6, 0xf6, 0, 0, 0, 0}};
 MagicNumberData aotelf_magic_number = {4, {0x7F, 0x45, 0x4C, 0x46, 0x0}};
+MagicNumberData aotpe_magic_number = {2, {0x4d, 0x5a}};
 MagicNumberData aotcoff_arm32_magic_number = {2, {0x01, 0xC0}};
 MagicNumberData aotcoff_arm64_magic_number = {2, {0xAA, 0x64}};
 MagicNumberData aotcoff_riscv32_magic_number = {2, {0x50, 0x32}};
@@ -404,6 +405,7 @@ DartUtils::MagicNumber DartUtils::SniffForMagicNumber(const char* filename) {
   ASSERT(aotelf_magic_number.length <= appjit_magic_number.length);
   ASSERT(static_cast<intptr_t>(sizeof(mach_o::mach_header::magic)) <=
          appjit_magic_number.length);
+  ASSERT(aotpe_magic_number.length <= appjit_magic_number.length);
   ASSERT(aotcoff_arm32_magic_number.length <= appjit_magic_number.length);
   ASSERT(aotcoff_arm64_magic_number.length <= appjit_magic_number.length);
   ASSERT(aotcoff_riscv32_magic_number.length <= appjit_magic_number.length);
@@ -465,6 +467,10 @@ DartUtils::MagicNumber DartUtils::SniffForMagicNumber(const uint8_t* buffer,
     }
   }
 
+  if (CheckMagicNumber(buffer, buffer_length, aotpe_magic_number)) {
+    return kAotPEMagicNumber;
+  }
+
   if (CheckMagicNumber(buffer, buffer_length, aotcoff_arm32_magic_number)) {
     return kAotCoffARM32MagicNumber;
   }

runtime/bin/dartutils.h

@@ -264,6 +264,7 @@ class DartUtils {
     // ("cigam") ones, as we can't load a reverse-endian snapshot anyway.
     kAotMachO32MagicNumber,
     kAotMachO64MagicNumber,
+    kAotPEMagicNumber,
     kAotCoffARM32MagicNumber,
     kAotCoffARM64MagicNumber,
     kAotCoffRISCV32MagicNumber,

runtime/bin/gen_snapshot.cc

@@ -297,6 +297,14 @@ static int ParseArguments(int argc,
             "an output file for --assembly.\n\n");
         return -1;
       }
+#if defined(DART_TARGET_OS_WINDOWS)
+      if (debugging_info_filename != nullptr) {
+        // TODO(https://github.com/dart-lang/sdk/issues/60812): Support PDB.
+        Syslog::PrintErr(
+            "warning: ignoring --save-debugging-info when "
+            "generating assembly for Windows.\n\n");
+      }
+#endif
       break;
     }
   }

runtime/include/dart_api.h

@@ -3998,7 +3998,8 @@ DART_EXPORT Dart_Handle Dart_LoadingUnitLibraryUris(intptr_t loading_unit_id);
  *  debugging sections.
  *
  *  If debug_callback_data is provided, debug_callback_data will be used with
- *  the callback to provide separate debugging information.
+ *  the callback to provide separate debugging information. Ignored when
+ *  targeting Windows.
  *
  *  \return A valid handle if no error occurs during the operation.
  */

runtime/tests/vm/dart/awaiter_stacks/harness.dart

@@ -249,8 +249,10 @@ bool shouldSkip() {
   final stack = StackTrace.current.toString();
   final isObfuscateMode = !stack.contains('shouldSkip');
   final isDwarfStackTracesMode = stack.contains('*** ***');
+  final isDLL = Platform.script.toString().endsWith(".dll");
 
   // We should skip the test if we are running without DWARF stack
-  // traces enabled but with obfuscation.
-  return !isDwarfStackTracesMode && isObfuscateMode;
+  // traces enabled but with obfuscation. Or if running from a DLL,
+  // which lacks DWARF.
+  return isDLL || (!isDwarfStackTracesMode && isObfuscateMode);
 }

runtime/tests/vm/dart/build_id_test.dart

@@ -3,14 +3,18 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:developer';
+import 'dart:io';
 
 import 'package:expect/expect.dart';
 
 import 'use_flag_test_helper.dart';
 
 void main() {
   final buildId = NativeRuntime.buildId;
-  if (isAOTRuntime) {
+
+  if (Platform.script.toString().endsWith(".dll")) {
+    Expect.isNull(buildId); // No build id in DLLs.
+  } else if (isAOTRuntime) {
     Expect.isNotNull(buildId);
     Expect.isTrue(buildId!.isNotEmpty, 'Build ID is an empty string');
   } else {

runtime/tests/vm/dart/use_dwarf_stack_traces_flag_deferred_test.dart

@@ -35,7 +35,11 @@ Future<void> main() async {
       'use_dwarf_stack_traces_flag_deferred_program.dart',
     ),
     runNonDwarf,
-    [runElf, runAssembly],
+    [
+      runElf,
+      // Don't run assembly on Windows since DLLs don't contain DWARF.
+      if (!Platform.isWindows) runAssembly,
+    ],
   );
 }
 

runtime/tests/vm/dart/use_dwarf_stack_traces_flag_helper.dart

@@ -23,7 +23,7 @@ Object get skipAssembly {
   if (isSimulator) {
     return "running on a simulated architecture";
   }
-  return (Platform.isLinux || Platform.isMacOS)
+  return (Platform.isLinux || Platform.isMacOS || Platform.isWindows)
       ? false
       : "no process for assembling snapshots on this platform";
 }