[NFC] AST: Define and use IterableDeclContext::getAsGenericContext()

Author: AnthonyLatsis

include/swift/AST/DeclContext.h

@@ -51,6 +51,7 @@ namespace swift {
   class Expr;
   class GenericParamList;
   class LazyMemberLoader;
+  class GenericContext;
   class GenericSignature;
   class GenericTypeParamDecl;
   class GenericTypeParamType;
@@ -818,6 +819,9 @@ class IterableDeclContext {
   /// Return 'this' as a \c Decl.
   const Decl *getDecl() const;
 
+  /// Return 'this' as a \c GenericContext.
+  const GenericContext *getAsGenericContext() const;
+
   /// Get the DeclID this Decl was deserialized from.
   serialization::DeclID getDeclID() const {
     assert(wasDeserialized());

lib/AST/DeclContext.cpp

@@ -766,6 +766,16 @@ IterableDeclContext::getDecl() const {
   llvm_unreachable("Unhandled IterableDeclContextKind in switch.");
 }
 
+const GenericContext *IterableDeclContext::getAsGenericContext() const {
+  switch (getIterableContextKind()) {
+  case IterableDeclContextKind::NominalTypeDecl:
+    return cast<NominalTypeDecl>(this);
+  case IterableDeclContextKind::ExtensionDecl:
+    return cast<ExtensionDecl>(this);
+  }
+  llvm_unreachable("Unhandled IterableDeclContextKind in switch.");
+}
+
 ASTContext &IterableDeclContext::getASTContext() const {
   return getDecl()->getASTContext();
 }
@@ -853,7 +863,7 @@ bool IterableDeclContext::hasUnparsedMembers() const {
   if (AddedParsedMembers)
     return false;
 
-  if (!getDecl()->getDeclContext()->getParentSourceFile()) {
+  if (!getAsGenericContext()->getParentSourceFile()) {
     // There will never be any parsed members to add, so set the flag to say
     // we are done so we can short-circuit next time.
     const_cast<IterableDeclContext *>(this)->AddedParsedMembers = 1;
@@ -873,7 +883,7 @@ void IterableDeclContext::loadAllMembers() const {
   ASTContext &ctx = getASTContext();
 
   // For contexts within a source file, get the list of parsed members.
-  if (getDecl()->getDeclContext()->getParentSourceFile()) {
+  if (getAsGenericContext()->getParentSourceFile()) {
     // Retrieve the parsed members. Even if we've already added the parsed
     // members to this context, this call is important for recording the
     // dependency edge.
@@ -911,7 +921,7 @@ void IterableDeclContext::loadAllMembers() const {
 }
 
 bool IterableDeclContext::wasDeserialized() const {
-  const DeclContext *DC = cast<DeclContext>(getDecl());
+  const DeclContext *DC = getAsGenericContext();
   if (auto F = dyn_cast<FileUnit>(DC->getModuleScopeContext())) {
     return F->getKind() == FileUnitKind::SerializedAST;
   }
@@ -943,7 +953,7 @@ IterableDeclContext::castDeclToIterableDeclContext(const Decl *D) {
 
 Optional<std::string> IterableDeclContext::getBodyFingerprint() const {
   // Only makes sense for contexts in a source file
-  if (!getDecl()->getDeclContext()->getParentSourceFile())
+  if (!getAsGenericContext()->getParentSourceFile())
     return None;
   auto mutableThis = const_cast<IterableDeclContext *>(this);
   return evaluateOrDefault(getASTContext().evaluator,

lib/Parse/ParseRequests.cpp

@@ -48,7 +48,7 @@ void swift::simple_display(llvm::raw_ostream &out,
 FingerprintAndMembers
 ParseMembersRequest::evaluate(Evaluator &evaluator,
                               IterableDeclContext *idc) const {
-  SourceFile &sf = *idc->getDecl()->getDeclContext()->getParentSourceFile();
+  SourceFile &sf = *idc->getAsGenericContext()->getParentSourceFile();
   unsigned bufferID = *sf.getBufferID();
 
   // Lexer diaganostics have been emitted during skipping, so we disable lexer's

lib/Sema/LookupVisibleDecls.cpp

@@ -539,7 +539,7 @@ static void
 // wrappers.
 static void
 synthesizePropertyWrapperStorageWrapperProperties(IterableDeclContext *IDC) {
-  auto SF = IDC->getDecl()->getDeclContext()->getParentSourceFile();
+  auto SF = IDC->getAsGenericContext()->getParentSourceFile();
   if (!SF || SF->Kind == SourceFileKind::Interface)
     return;
 

lib/SymbolGraphGen/Edge.cpp

@@ -42,20 +42,19 @@ void Edge::serialize(llvm::json::OStream &OS) const {
     }
 
     if (ConformanceExtension) {
-      if (const auto *Generics = ConformanceExtension->getAsGenericContext()) {
-        SmallVector<Requirement, 4> FilteredRequirements;
-        filterGenericRequirements(Generics->getGenericRequirements(),
-            ConformanceExtension->getExtendedNominal()
-                ->getDeclContext()->getSelfNominalTypeDecl(),
-                                  FilteredRequirements);
-        if (!FilteredRequirements.empty()) {
-          OS.attributeArray("swiftConstraints", [&](){
-            for (const auto &Req :
-                 ConformanceExtension->getGenericRequirements()) {
-              ::serialize(Req, OS);
-            }
-          });
-        }
+      SmallVector<Requirement, 4> FilteredRequirements;
+      filterGenericRequirements(
+          ConformanceExtension->getGenericRequirements(),
+          ConformanceExtension->getExtendedNominal()
+              ->getDeclContext()->getSelfNominalTypeDecl(),
+                                FilteredRequirements);
+      if (!FilteredRequirements.empty()) {
+        OS.attributeArray("swiftConstraints", [&](){
+          for (const auto &Req :
+               ConformanceExtension->getGenericRequirements()) {
+            ::serialize(Req, OS);
+          }
+        });
       }
     }
   });

lib/SymbolGraphGen/JSON.cpp

@@ -66,21 +66,20 @@ void swift::symbolgraphgen::serialize(const ExtensionDecl *Extension,
         OS.attribute("extendedModule", ExtendedModule->getNameStr());
       }
     }
-    if (const auto Generics = Extension->getAsGenericContext()) {
-      SmallVector<Requirement, 4> FilteredRequirements;
-
-      filterGenericRequirements(Generics->getGenericRequirements(),
-          Extension->getExtendedNominal()
-              ->getDeclContext()->getSelfNominalTypeDecl(),
-                                FilteredRequirements);
-
-      if (!FilteredRequirements.empty()) {
-        OS.attributeArray("constraints", [&](){
-          for (const auto &Requirement : FilteredRequirements) {
-            serialize(Requirement, OS);
-          }
-        }); // end constraints:
-      }
+
+    SmallVector<Requirement, 4> FilteredRequirements;
+
+    filterGenericRequirements(Extension->getGenericRequirements(),
+        Extension->getExtendedNominal()
+            ->getDeclContext()->getSelfNominalTypeDecl(),
+                              FilteredRequirements);
+
+    if (!FilteredRequirements.empty()) {
+      OS.attributeArray("constraints", [&](){
+        for (const auto &Requirement : FilteredRequirements) {
+          serialize(Requirement, OS);
+        }
+      }); // end constraints:
     }
   }); // end swiftExtension:
 }