[Sema] Pass self nominal type as a parameter to CheckRedeclarationRequest

The self nominal type decl needs to be passed as a parameter in here so this request doesn't tigger self nominal type computation, which results in an assertion failure.

Author: ahoppen

include/swift/AST/TypeCheckRequests.h

@@ -3103,7 +3103,8 @@ class LookupAllConformancesInContextRequest
 
 class CheckRedeclarationRequest
     : public SimpleRequest<
-          CheckRedeclarationRequest, evaluator::SideEffect(ValueDecl *),
+          CheckRedeclarationRequest,
+          evaluator::SideEffect(ValueDecl *, NominalTypeDecl *),
           RequestFlags::SeparatelyCached | RequestFlags::DependencySource |
               RequestFlags::DependencySink> {
 public:
@@ -3113,10 +3114,13 @@ class CheckRedeclarationRequest
   friend SimpleRequest;
 
    // Evaluation.
-  evaluator::SideEffect
-  evaluate(Evaluator &evaluator, ValueDecl *VD) const;
+  /// \p SelfNominalType is \c VD->getDeclContext()->getSelfNominalType().
+  /// Passed as a parameter in here so this request doesn't tigger self nominal
+  /// type computation.
+  evaluator::SideEffect evaluate(Evaluator &evaluator, ValueDecl *VD,
+                                 NominalTypeDecl *SelfNominalType) const;
 
- public:
+public:
   // Separate caching.
   bool isCached() const { return true; }
   Optional<evaluator::SideEffect> getCachedResult() const;

lib/AST/TypeCheckRequests.cpp

@@ -1324,7 +1324,7 @@ void CheckRedeclarationRequest::writeDependencySink(
     return;
 
   if (currentDC->isTypeContext()) {
-    if (auto nominal = currentDC->getSelfNominalTypeDecl()) {
+    if (auto nominal = std::get<1>(getStorage())) {
       tracker.addUsedMember(nominal, current->getBaseName());
     }
   } else {

lib/Sema/TypeCheckDeclPrimary.cpp

@@ -542,7 +542,8 @@ static void checkRedeclaration(PrecedenceGroupDecl *group) {
 
 /// Check whether \c current is a redeclaration.
 evaluator::SideEffect
-CheckRedeclarationRequest::evaluate(Evaluator &eval, ValueDecl *current) const {
+CheckRedeclarationRequest::evaluate(Evaluator &eval, ValueDecl *current,
+                                    NominalTypeDecl *SelfNominalType) const {
   // Ignore invalid and anonymous declarations.
   if (current->isInvalid() || !current->hasName())
     return std::make_tuple<>();
@@ -1872,8 +1873,11 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
       // Force some requests, which can produce diagnostics.
 
       // Check redeclaration.
-      (void) evaluateOrDefault(Context.evaluator,
-                               CheckRedeclarationRequest{VD}, {});
+      (void)evaluateOrDefault(
+          Context.evaluator,
+          CheckRedeclarationRequest{
+              VD, VD->getDeclContext()->getSelfNominalTypeDecl()},
+          {});
 
       // Compute access level.
       (void) VD->getFormalAccess();

test/SourceKit/CursorInfo/cursor_on_var_in_extension_in_func.swift

@@ -0,0 +1,6 @@
+func foo() {
+  extension XXX {
+// RUN: %sourcekitd-test -req=cursor -pos=%(line + 1):9 %s -- %s
+    var hex 
+  }
+}