[dart2wasm] Make slow path call StackTrace.current on null errors

For throwing normal exceptions we already outlined obtaining
the current stack. We can do this for null check errors as well.

Change-Id: Ie0505bfd99ff9c6738040c47b07e542439ee74a5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/419161
Reviewed-by: Ömer Ağacan <[email protected]>
Commit-Queue: Martin Kustermann <[email protected]>

Author: mkustermann

pkg/dart2wasm/lib/async.dart

@@ -274,6 +274,15 @@ class AsyncStateMachineCodeGenerator extends StateMachineCodeGenerator {
       b.return_();
     }
 
+    void callCompleteErrorWithCurrentStack() {
+      b.local_get(_suspendStateLocal);
+      b.struct_get(
+          asyncSuspendStateInfo.struct, FieldIndex.asyncSuspendStateCompleter);
+      b.local_get(exceptionLocal);
+      call(translator.completerCompleteErrorWithCurrentStack.reference);
+      b.return_();
+    }
+
     // Handle Dart exceptions.
     b.catch_legacy(translator.getExceptionTag(b.module));
     b.local_set(stackTraceLocal);
@@ -289,10 +298,7 @@ class AsyncStateMachineCodeGenerator extends StateMachineCodeGenerator {
 
     // JS exceptions won't have a Dart stack trace, so we attach the current
     // Dart stack trace.
-    call(translator.stackTraceCurrent.reference);
-    b.local_set(stackTraceLocal);
-
-    callCompleteError();
+    callCompleteErrorWithCurrentStack();
 
     b.end(); // try
 

pkg/dart2wasm/lib/code_generator.dart

@@ -2651,8 +2651,7 @@ abstract class AstCodeGenerator
     // We lower a null check to a br_on_non_null, throwing a [TypeError] in
     // the null case.
     b.br_on_non_null(nullCheckBlock);
-    call(translator.stackTraceCurrent.reference);
-    call(translator.throwNullCheckError.reference);
+    call(translator.throwNullCheckErrorWithCurrentStack.reference);
     b.unreachable();
     b.end();
     return nonNullOperandType;

pkg/dart2wasm/lib/kernel_nodes.dart

@@ -147,6 +147,9 @@ mixin KernelNodes {
       index.getField("dart:async", "_Completer", "future");
   late final Procedure completerComplete =
       index.getProcedure("dart:async", "_AsyncCompleter", "complete");
+  late final Procedure completerCompleteErrorWithCurrentStack =
+      index.getProcedure(
+          "dart:async", "_AsyncCompleter", "_completeErrorWithCurrentStack");
   late final Procedure completerCompleteError =
       index.getProcedure("dart:async", "_Completer", "completeError");
   late final Procedure awaitHelper =
@@ -290,8 +293,8 @@ mixin KernelNodes {
           "_throwUnimplementedExternalMemberError");
   late final Procedure stackTraceCurrent =
       index.getProcedure("dart:core", "StackTrace", "get:current");
-  late final Procedure throwNullCheckError =
-      index.getProcedure("dart:core", "_TypeError", "_throwNullCheckError");
+  late final Procedure throwNullCheckErrorWithCurrentStack = index.getProcedure(
+      "dart:core", "_TypeError", "_throwNullCheckErrorWithCurrentStack");
   late final Procedure throwAsCheckError =
       index.getProcedure("dart:core", "_TypeError", "_throwAsCheckError");
   late final Procedure throwInterfaceTypeAsCheckError1 = index

sdk/lib/_internal/wasm/lib/async_patch.dart

@@ -84,6 +84,15 @@ _AsyncSuspendState _newAsyncSuspendState(
 @pragma("wasm:entry-point")
 _AsyncCompleter<T> _makeAsyncCompleter<T>() => _AsyncCompleter<T>();
 
+@patch
+@pragma("wasm:entry-point")
+class _AsyncCompleter<T> extends _Completer<T> {
+  @pragma("wasm:entry-point")
+  void _completeErrorWithCurrentStack(Object error) {
+    completeError(error, StackTrace.current);
+  }
+}
+
 @pragma("wasm:entry-point")
 void _awaitHelper(_AsyncSuspendState suspendState, Object? operand) {
   if (operand is! Future) {

sdk/lib/_internal/wasm/lib/errors_patch.dart

@@ -73,7 +73,9 @@ class _TypeError extends _Error implements TypeError {
   }
 
   @pragma("wasm:entry-point")
-  static Never _throwNullCheckError(StackTrace stackTrace) {
+  @pragma("wasm:never-inline")
+  static Never _throwNullCheckErrorWithCurrentStack() {
+    final stackTrace = StackTrace.current;
     final typeError = _TypeError.fromMessageAndStackTrace(
       "Null check operator used on a null value",
       stackTrace,