Merge pull request swiftlang#28605 from nathawes/fix-unreachable-in-addSameTypeRequirementBetweenConcrete-during-completion

[AST] Handle visiting UnresolvedType in TypeMatcher

Author: Nathan Hawes

include/swift/AST/CanTypeVisitor.h

@@ -31,15 +31,12 @@ class CanTypeVisitor {
 public:
   RetTy visit(CanType T, Args... args) {
     switch (T->getKind()) {
-#define UNCHECKED_TYPE(CLASS, PARENT) \
-    case TypeKind::CLASS:
 #define SUGARED_TYPE(CLASS, PARENT) \
     case TypeKind::CLASS:
 #define TYPE(CLASS, PARENT)
 #include "swift/AST/TypeNodes.def"
-      llvm_unreachable("non-canonical or unchecked type");
+      llvm_unreachable("non-canonical type");
 
-#define UNCHECKED_TYPE(CLASS, PARENT)
 #define SUGARED_TYPE(CLASS, PARENT)
 #define TYPE(CLASS, PARENT)                                  \
     case TypeKind::CLASS:                                    \
@@ -64,7 +61,12 @@ class CanTypeVisitor {
 #define TYPE(CLASS, PARENT) ABSTRACT_TYPE(CLASS, PARENT)
 #define ABSTRACT_SUGARED_TYPE(CLASS, PARENT)
 #define SUGARED_TYPE(CLASS, PARENT)
-#define UNCHECKED_TYPE(CLASS, PARENT)
+  // Don't allow unchecked types by default, but allow visitors to opt-in to
+  // handling them.
+#define UNCHECKED_TYPE(CLASS, PARENT)                          \
+  RetTy visit##CLASS##Type(Can##CLASS##Type T, Args... args) { \
+     llvm_unreachable("unchecked type");                       \
+  }
 #include "swift/AST/TypeNodes.def"
 };
 

include/swift/AST/TypeMatcher.h

@@ -111,6 +111,13 @@ class TypeMatcher {
     TRIVIAL_CASE(BuiltinVectorType)
     TRIVIAL_CASE(SILTokenType)
 
+    bool visitUnresolvedType(CanUnresolvedType firstType, Type secondType,
+                             Type sugaredFirstType) {
+      // Unresolved types never match.
+      return mismatch(firstType.getPointer(), secondType,                \
+                      sugaredFirstType);                                 \
+    }
+
     bool visitTupleType(CanTupleType firstTuple, Type secondType,
                         Type sugaredFirstType) {
       if (auto secondTuple = secondType->getAs<TupleType>()) {
@@ -264,23 +271,6 @@ class TypeMatcher {
       return mismatch(firstInOut.getPointer(), secondType, sugaredFirstType);
     }
 
-    bool visitUnboundBoundGenericType(CanUnboundGenericType firstUBGT,
-                                      Type secondType, Type sugaredFirstType) {
-      if (auto secondUBGT = secondType->getAs<UnboundGenericType>()) {
-        if (firstUBGT->getDecl() != secondUBGT->getDecl())
-          return mismatch(firstUBGT.getPointer(), secondUBGT, sugaredFirstType);
-
-        if (firstUBGT.getParent())
-          return this->visit(firstUBGT.getParent(), secondUBGT->getParent(),
-                             sugaredFirstType->castTo<UnboundGenericType>()
-                               ->getParent());
-
-        return true;
-      }
-
-      return mismatch(firstUBGT.getPointer(), secondType, sugaredFirstType);
-    }
-
     bool visitBoundGenericType(CanBoundGenericType firstBGT,
                                Type secondType, Type sugaredFirstType) {
       auto _secondBGT = secondType->getCanonicalType();
@@ -309,8 +299,6 @@ class TypeMatcher {
       return mismatch(firstBGT.getPointer(), secondType, sugaredFirstType);
     }
 
-    TRIVIAL_CASE(TypeVariableType)
-
 #undef TRIVIAL_CASE
   };
 

test/IDE/complete_uninferred_generic.swift

@@ -0,0 +1,18 @@
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=UNINFERRED | %FileCheck %s -check-prefix=UNINFERRED
+
+struct S1<V0> {}
+protocol P1 {
+    associatedtype A1
+}
+extension P1 where A1 == S1<Int> {
+    subscript<T>(v0: T) -> Int  { fatalError() }
+    subscript<T>(v0: T) -> Undefined { fatalError() }
+}
+struct S2<T> : P1 {
+    typealias A1 = S1<T>
+}
+_ = S2()#^UNINFERRED^#
+
+// UNINFERRED: Decl[Subscript]/Super:     [{#(v0): T#}][#Int#]; name=[v0: T]
+// UNINFERRED: Decl[Subscript]/Super:     [{#(v0): T#}][#<<error type>>#]; name=[v0: T]
+// UNINFERRED: Keyword[self]/CurrNominal: .self[#S2<_>#]; name=self