Sema: Don't crash if a property with an opaque result type has both an initial value and a getter

Author: slavapestov

lib/Sema/CSApply.cpp

@@ -9446,23 +9446,26 @@ applySolutionToInitialization(SyntacticElementTarget target, Expr *initializer,
   // If this property has an opaque result type, set the underlying type
   // substitutions based on the initializer.
   if (auto var = resultTarget.getInitializationPattern()->getSingleVar()) {
-    SubstitutionMap substitutions;
-    if (auto opaque = var->getOpaqueResultTypeDecl()) {
-      resultTarget.getAsExpr()->forEachChildExpr([&](Expr *expr) -> Expr * {
-        if (auto coercionExpr = dyn_cast<UnderlyingToOpaqueExpr>(expr)) {
-          auto newSubstitutions =
-              coercionExpr->substitutions.mapReplacementTypesOutOfContext();
-          if (substitutions.empty()) {
-            substitutions = newSubstitutions;
-          } else {
-            assert(substitutions.getCanonical() ==
-                       newSubstitutions.getCanonical());
+    if (!var->getParsedAccessor(AccessorKind::Get)) {
+      if (auto opaque = var->getOpaqueResultTypeDecl()) {
+        SubstitutionMap substitutions;
+
+        resultTarget.getAsExpr()->forEachChildExpr([&](Expr *expr) -> Expr * {
+          if (auto coercionExpr = dyn_cast<UnderlyingToOpaqueExpr>(expr)) {
+            auto newSubstitutions =
+                coercionExpr->substitutions.mapReplacementTypesOutOfContext();
+            if (substitutions.empty()) {
+              substitutions = newSubstitutions;
+            } else {
+              assert(substitutions.getCanonical() ==
+                         newSubstitutions.getCanonical());
+            }
           }
-        }
-        return expr;
-      });
+          return expr;
+        });
 
-      opaque->setUniqueUnderlyingTypeSubstitutions(substitutions);
+        opaque->setUniqueUnderlyingTypeSubstitutions(substitutions);
+      }
     }
   }
 

validation-test/compiler_crashers_2/88e136b5aa17e82f.swift renamed to validation-test/compiler_crashers_2_fixed/88e136b5aa17e82f.swift

@@ -1,5 +1,5 @@
 // {"kind":"typecheck","original":"3a2652c9","signature":"(anonymous namespace)::OpaqueUnderlyingTypeChecker::check()","signatureAssert":"Assertion failed: (!UniqueUnderlyingType.has_value() && \"resetting underlying type?!\"), function setUniqueUnderlyingTypeSubstitutions"}
-// RUN: not --crash %target-swift-frontend -typecheck %s
+// RUN: not %target-swift-frontend -typecheck %s
 var a: some Any = 0.0 {
   0
 }