Merge pull request #27003 from slavapestov/remove-ignore-new-extensions

Remove IgnoreNewExtensions and related cleanups

Author: slavapestov

include/swift/AST/ASTContext.h

@@ -17,7 +17,6 @@
 #ifndef SWIFT_AST_ASTCONTEXT_H
 #define SWIFT_AST_ASTCONTEXT_H
 
-#include "swift/AST/ClangModuleLoader.h"
 #include "swift/AST/Evaluator.h"
 #include "swift/AST/GenericSignature.h"
 #include "swift/AST/Identifier.h"
@@ -32,6 +31,7 @@
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/PointerIntPair.h"
 #include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/TinyPtrVector.h"
 #include "llvm/Support/Allocator.h"
@@ -49,10 +49,12 @@ namespace clang {
 }
 
 namespace swift {
+  class AbstractFunctionDecl;
   class ASTContext;
   enum class Associativity : unsigned char;
   class AvailabilityContext;
   class BoundGenericType;
+  class ClangModuleLoader;
   class ClangNode;
   class ConcreteDeclRef;
   class ConstructorDecl;

include/swift/AST/Decl.h

@@ -543,7 +543,7 @@ class alignas(1 << DeclAlignInBits) Decl {
     NumRequirementsInSignature : 16
   );
 
-  SWIFT_INLINE_BITFIELD(ClassDecl, NominalTypeDecl, 2+1+2+1+7+1+1+1+1,
+  SWIFT_INLINE_BITFIELD(ClassDecl, NominalTypeDecl, 2+1+2+1+7+1+1+1+1+1+1,
     /// The stage of the inheritance circularity check for this class.
     Circularity : 2,
 
@@ -557,7 +557,10 @@ class alignas(1 << DeclAlignInBits) Decl {
     HasForcedEmittedMembers : 1,     
 
     HasMissingDesignatedInitializers : 1,
+    ComputedHasMissingDesignatedInitializers : 1,
+
     HasMissingVTableEntries : 1,
+    ComputedHasMissingVTableEntries : 1,
 
     /// Whether instances of this class are incompatible
     /// with weak and unowned references.
@@ -3272,7 +3275,7 @@ class NominalTypeDecl : public GenericTypeDecl, public IterableDeclContext {
   llvm::PointerIntPair<MemberLookupTable *, 1, bool> LookupTable;
 
   /// Prepare the lookup table to make it ready for lookups.
-  void prepareLookupTable(bool ignoreNewExtensions);
+  void prepareLookupTable();
 
   /// True if the entries in \c LookupTable are complete--that is, if a
   /// name is present, it contains all members with that name.
@@ -3378,24 +3381,11 @@ class NominalTypeDecl : public GenericTypeDecl, public IterableDeclContext {
   /// Retrieve the set of extensions of this type.
   ExtensionRange getExtensions();
 
-  /// Make a member of this nominal type, or one of its extensions,
-  /// immediately visible in the lookup table.
-  ///
-  /// A member of a nominal type or extension thereof will become
-  /// visible to name lookup as soon as it is added. However, if the
-  /// addition of a member is delayed---for example, because it's
-  /// being introduced in response to name lookup---this method can be
-  /// called to make it immediately visible.
-  void makeMemberVisible(ValueDecl *member);
-
   /// Special-behaviour flags passed to lookupDirect()
   enum class LookupDirectFlags {
-    /// Whether to avoid loading any new extension.
-    /// Used by the module loader to break recursion.
-    IgnoreNewExtensions = 1 << 0,
     /// Whether to include @_implements members.
     /// Used by conformance-checking to find special @_implements members.
-    IncludeAttrImplements = 1 << 1,
+    IncludeAttrImplements = 1 << 0,
   };
 
   /// Find all of the declarations with the given name within this nominal type
@@ -3879,6 +3869,7 @@ class ClassDecl final : public NominalTypeDecl {
   bool hasMissingDesignatedInitializers() const;
 
   void setHasMissingDesignatedInitializers(bool newValue = true) {
+    Bits.ClassDecl.ComputedHasMissingDesignatedInitializers = 1;
     Bits.ClassDecl.HasMissingDesignatedInitializers = newValue;
   }
 
@@ -3889,6 +3880,7 @@ class ClassDecl final : public NominalTypeDecl {
   bool hasMissingVTableEntries() const;
 
   void setHasMissingVTableEntries(bool newValue = true) {
+    Bits.ClassDecl.ComputedHasMissingVTableEntries = 1;
     Bits.ClassDecl.HasMissingVTableEntries = newValue;
   }
 
@@ -4195,6 +4187,14 @@ class ProtocolDecl final : public NominalTypeDecl {
   /// a protocol having nested types (ObjC protocols).
   llvm::TinyPtrVector<AssociatedTypeDecl *> getAssociatedTypeMembers() const;
 
+  /// Returns a protocol requirement with the given name, or nullptr if the
+  /// name has multiple overloads, or no overloads at all.
+  ValueDecl *getSingleRequirement(DeclName name) const;
+
+  /// Returns an associated type with the given name, or nullptr if one does
+  /// not exist.
+  AssociatedTypeDecl *getAssociatedType(Identifier name) const;
+
   /// Walk this protocol and all of the protocols inherited by this protocol,
   /// transitively, invoking the callback function for each protocol.
   ///

include/swift/ClangImporter/ClangImporter.h

@@ -51,11 +51,13 @@ class ClangModuleUnit;
 class ClangNode;
 class Decl;
 class DeclContext;
+class EnumDecl;
 class ImportDecl;
 class IRGenOptions;
 class LazyResolver;
 class ModuleDecl;
 class NominalTypeDecl;
+class StructDecl;
 class TypeDecl;
 class VisibleDeclConsumer;
 enum class SelectorSplitKind;
@@ -213,6 +215,9 @@ class ClangImporter final : public ClangModuleLoader {
                       StringRef relatedEntityKind,
                       llvm::function_ref<void(TypeDecl *)> receiver) override;
 
+  /// Look up the nested 'Code' enum for an error wrapper struct.
+  EnumDecl *lookupErrorCodeEnum(const StructDecl *errorWrapper) const;
+
   /// Look for textually included declarations from the bridging header.
   ///
   /// \param filter returns true if the given clang decl/macro should be

lib/AST/ASTContext.cpp

@@ -17,6 +17,7 @@
 #include "swift/AST/ASTContext.h"
 #include "ForeignRepresentationInfo.h"
 #include "SubstitutionMapStorage.h"
+#include "swift/AST/ClangModuleLoader.h"
 #include "swift/AST/ConcreteDeclRef.h"
 #include "swift/AST/DiagnosticEngine.h"
 #include "swift/AST/DiagnosticsSema.h"

lib/AST/ASTDemangler.cpp

@@ -84,11 +84,7 @@ TypeDecl *ASTBuilder::createTypeDecl(NodePointer node) {
       return nullptr;
 
     auto name = Ctx.getIdentifier(node->getChild(1)->getText());
-    auto results = proto->lookupDirect(name);
-    if (results.size() != 1)
-      return nullptr;
-
-    return dyn_cast<AssociatedTypeDecl>(results[0]);
+    return proto->getAssociatedType(name);
   }
 
   auto *DC = findDeclContext(node);
@@ -585,13 +581,8 @@ Type ASTBuilder::createDependentMemberType(StringRef member,
   if (!base->isTypeParameter())
     return Type();
 
-  auto flags = OptionSet<NominalTypeDecl::LookupDirectFlags>();
-  flags |= NominalTypeDecl::LookupDirectFlags::IgnoreNewExtensions;
-  for (auto member : protocol->lookupDirect(Ctx.getIdentifier(member),
-                                            flags)) {
-    if (auto assocType = dyn_cast<AssociatedTypeDecl>(member))
-      return DependentMemberType::get(base, assocType);
-  }
+  if (auto assocType = protocol->getAssociatedType(Ctx.getIdentifier(member)))
+    return DependentMemberType::get(base, assocType);
 
   return Type();
 }

lib/AST/Decl.cpp

@@ -3816,7 +3816,9 @@ ClassDecl::ClassDecl(SourceLoc ClassLoc, Identifier Name, SourceLoc NameLoc,
   Bits.ClassDecl.InheritsSuperclassInits = 0;
   Bits.ClassDecl.RawForeignKind = 0;
   Bits.ClassDecl.HasMissingDesignatedInitializers = 0;
+  Bits.ClassDecl.ComputedHasMissingDesignatedInitializers = 0;
   Bits.ClassDecl.HasMissingVTableEntries = 0;
+  Bits.ClassDecl.ComputedHasMissingVTableEntries = 0;
   Bits.ClassDecl.IsIncompatibleWithWeakReferences = 0;
 }
 
@@ -3901,16 +3903,22 @@ GetDestructorRequest::evaluate(Evaluator &evaluator, ClassDecl *CD) const {
 
 
 bool ClassDecl::hasMissingDesignatedInitializers() const {
-  auto *mutableThis = const_cast<ClassDecl *>(this);
-  auto flags = OptionSet<LookupDirectFlags>();
-  flags |= LookupDirectFlags::IgnoreNewExtensions;
-  (void)mutableThis->lookupDirect(DeclBaseName::createConstructor(),
-                                  flags);
+  if (!Bits.ClassDecl.ComputedHasMissingDesignatedInitializers) {
+    auto *mutableThis = const_cast<ClassDecl *>(this);
+    mutableThis->Bits.ClassDecl.ComputedHasMissingDesignatedInitializers = 1;
+    (void)mutableThis->lookupDirect(DeclBaseName::createConstructor());
+  }
+
   return Bits.ClassDecl.HasMissingDesignatedInitializers;
 }
 
 bool ClassDecl::hasMissingVTableEntries() const {
-  (void)getMembers();
+  if (!Bits.ClassDecl.ComputedHasMissingVTableEntries) {
+    auto *mutableThis = const_cast<ClassDecl *>(this);
+    mutableThis->Bits.ClassDecl.ComputedHasMissingVTableEntries = 1;
+    mutableThis->loadAllMembers();
+  }
+
   return Bits.ClassDecl.HasMissingVTableEntries;
 }
 
@@ -4364,6 +4372,34 @@ ProtocolDecl::getAssociatedTypeMembers() const {
   return result;
 }
 
+ValueDecl *ProtocolDecl::getSingleRequirement(DeclName name) const {
+  auto results = const_cast<ProtocolDecl *>(this)->lookupDirect(name);
+  ValueDecl *result = nullptr;
+  for (auto candidate : results) {
+    if (candidate->getDeclContext() != this ||
+        !candidate->isProtocolRequirement())
+      continue;
+    if (result) {
+      // Multiple results.
+      return nullptr;
+    }
+    result = candidate;
+  }
+
+  return result;
+}
+
+AssociatedTypeDecl *ProtocolDecl::getAssociatedType(Identifier name) const {
+  auto results = const_cast<ProtocolDecl *>(this)->lookupDirect(name);
+  for (auto candidate : results) {
+    if (candidate->getDeclContext() == this &&
+        isa<AssociatedTypeDecl>(candidate)) {
+      return cast<AssociatedTypeDecl>(candidate);
+    }
+  }
+  return nullptr;
+}
+
 Type ProtocolDecl::getSuperclass() const {
   ASTContext &ctx = getASTContext();
   return evaluateOrDefault(ctx.evaluator,

lib/AST/ImportCache.cpp

@@ -17,6 +17,7 @@
 
 #include "llvm/ADT/DenseSet.h"
 #include "swift/AST/ASTContext.h"
+#include "swift/AST/ClangModuleLoader.h"
 #include "swift/AST/ImportCache.h"
 #include "swift/AST/Module.h"
 

lib/AST/ModuleNameLookup.cpp

@@ -12,6 +12,7 @@
 
 #include "swift/AST/ModuleNameLookup.h"
 #include "swift/AST/ASTContext.h"
+#include "swift/AST/ClangModuleLoader.h"
 #include "swift/AST/ImportCache.h"
 #include "swift/AST/NameLookup.h"
 #include "llvm/Support/raw_ostream.h"