[macros] Find platform for Flutter desktop build.

[email protected], [email protected]

Change-Id: I78bb5bccc0191986d788da2386484b6128fa256e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/357343
Reviewed-by: Johnni Winther <[email protected]>
Auto-Submit: Morgan :) <[email protected]>
Commit-Queue: Morgan :) <[email protected]>
Commit-Queue: Johnni Winther <[email protected]>

Author: davidmorgan

pkg/front_end/lib/src/macros/macro_target.dart

@@ -10,11 +10,24 @@ import 'unsupported_vm_target.dart'
 MacroConfiguration computeMacroConfiguration({Uri? targetSdkSummary}) {
   // Force the SDK summary to "vm_platform_strong.dill".
   // TODO(54404): make this sufficiently correct for all use cases.
-  Uri? sdkSummary = (targetSdkSummary == null ||
-          targetSdkSummary.path == 'virtual_platform_kernel.dill' ||
-          targetSdkSummary.path.contains('vm_platform_strong.dill'))
-      ? targetSdkSummary
-      : targetSdkSummary.resolve('./vm_platform_strong.dill');
+
+  Uri? sdkSummary;
+  if ((targetSdkSummary == null ||
+      targetSdkSummary.path == 'virtual_platform_kernel.dill' ||
+      targetSdkSummary.path.contains('vm_platform_strong.dill'))) {
+    sdkSummary = targetSdkSummary;
+  } else if (targetSdkSummary.path.contains('/platform_strong.dill')) {
+    // Flutter. Expecting the dill to be
+    // bin/cache/artifacts/engine/common/flutter_patched_sdk/platform_strong.dill
+    // and the Dart SDK to be under bin/cache/dart-sdk.
+    sdkSummary = targetSdkSummary.resolve(
+        './../../../../dart-sdk/lib/_internal/vm_platform_strong.dill');
+  } else {
+    // Non-VM target platform, not Flutter. Find the platform dill next to the
+    // non-VM platform dill.
+    sdkSummary = targetSdkSummary.resolve('./vm_platform_strong.dill');
+  }
+
   return new MacroConfiguration(
       target: new VmTarget(
           new TargetFlags(soundNullSafety: true, supportMirrors: false)),