[AST] Remove SerializedPatternBindingInitializer

This stores the same state as
PatternBindingInitializer, we can use that
instead.

Author: hamishknight

include/swift/AST/DeclContext.h

@@ -79,7 +79,6 @@ namespace swift {
   class Initializer;
   class ClassDecl;
   class SerializedAbstractClosureExpr;
-  class SerializedPatternBindingInitializer;
   class SerializedDefaultArgumentInitializer;
   class SerializedTopLevelCodeDecl;
   class StructDecl;
@@ -115,7 +114,6 @@ enum class DeclContextKind : unsigned {
 /// \see SerializedLocalDeclContext.
 enum class LocalDeclContextKind : uint8_t {
   AbstractClosure,
-  PatternBindingInitializer,
   DefaultArgumentInitializer,
   TopLevelCodeDecl
 };

include/swift/AST/Initializer.h

@@ -95,6 +95,9 @@ class PatternBindingInitializer : public Initializer {
     return new (parent->getASTContext()) PatternBindingInitializer(parent);
   }
 
+  static PatternBindingInitializer *createDeserialized(PatternBindingDecl *PBD,
+                                                       unsigned index);
+
   void setBinding(PatternBindingDecl *binding, unsigned bindingIndex) {
     setParent(binding->getDeclContext());
     Binding = binding;
@@ -122,37 +125,6 @@ class PatternBindingInitializer : public Initializer {
   }
 };
 
-/// SerializedPatternBindingInitializer - This represents what was originally a
-/// PatternBindingInitializer during serialization. It is preserved as a special
-/// class only to maintain the correct AST structure and remangling after
-/// deserialization.
-class SerializedPatternBindingInitializer : public SerializedLocalDeclContext {
-  PatternBindingDecl *Binding;
-
-public:
-  SerializedPatternBindingInitializer(PatternBindingDecl *Binding,
-                                      unsigned bindingIndex)
-    : SerializedLocalDeclContext(LocalDeclContextKind::PatternBindingInitializer,
-                                 Binding->getDeclContext()),
-      Binding(Binding) {
-    SpareBits = bindingIndex;
-  }
-
-  PatternBindingDecl *getBinding() const {
-    return Binding;
-  }
-
-  unsigned getBindingIndex() const { return SpareBits; }
-
-
-  static bool classof(const DeclContext *DC) {
-    if (auto LDC = dyn_cast<SerializedLocalDeclContext>(DC))
-      return LDC->getLocalDeclContextKind() ==
-      LocalDeclContextKind::PatternBindingInitializer;
-    return false;
-  }
-};
-
 /// A default argument expression.  The parent context is the function
 /// (possibly a closure) for which this is a default argument.
 class DefaultArgumentInitializer : public Initializer {

lib/AST/ASTMangler.cpp

@@ -2328,17 +2328,6 @@ void ASTMangler::appendContext(const DeclContext *ctx, StringRef useModuleName)
       appendDefaultArgumentEntity(ctx->getParent(), argInit->getIndex());
       return;
     }
-    case LocalDeclContextKind::PatternBindingInitializer: {
-      auto patternInit = cast<SerializedPatternBindingInitializer>(local);
-      if (auto var = findFirstVariable(patternInit->getBinding())) {
-        appendInitializerEntity(var.value());
-      } else {
-        // This is incorrect in that it does not produce a /unique/ mangling,
-        // but it will at least produce a /valid/ mangling.
-        appendContext(ctx->getParent(), useModuleName);
-      }
-      return;
-    }
     case LocalDeclContextKind::TopLevelCodeDecl:
       return appendContext(local->getParent(), useModuleName);
     }

lib/AST/Decl.cpp

@@ -1961,6 +1961,14 @@ PatternBindingDecl *PatternBindingDecl::createDeserialized(
   return PBD;
 }
 
+PatternBindingInitializer *
+PatternBindingInitializer::createDeserialized(PatternBindingDecl *PBD,
+                                              unsigned index) {
+  auto *init = PatternBindingInitializer::create(PBD->getDeclContext());
+  init->setBinding(PBD, index);
+  return init;
+}
+
 ParamDecl *PatternBindingInitializer::getImplicitSelfDecl() const {
   if (SelfParam)
     return SelfParam;

lib/AST/DeclContext.cpp

@@ -829,12 +829,6 @@ unsigned DeclContext::printContext(raw_ostream &OS, const unsigned indent,
       OS << "DefaultArgument index=" << init->getIndex();
       break;
     }
-    case LocalDeclContextKind::PatternBindingInitializer: {
-      auto init = cast<SerializedPatternBindingInitializer>(local);
-      OS << " PatternBinding 0x" << (void*) init->getBinding()
-         << " #" << init->getBindingIndex();
-      break;
-    }
     case LocalDeclContextKind::TopLevelCodeDecl:
       OS << " TopLevelCode";
       break;

lib/Serialization/Deserialization.cpp

@@ -2657,10 +2657,10 @@ Expected<DeclContext *>ModuleFile::getLocalDeclContext(LocalDeclContextID DCID)
     auto decl = getDecl(bindingID);
     PatternBindingDecl *binding = cast<PatternBindingDecl>(decl);
 
-    if (!declContextOrOffset.isComplete())
-      declContextOrOffset = new (ctx)
-        SerializedPatternBindingInitializer(binding, bindingIndex);
-
+    if (!declContextOrOffset.isComplete()) {
+      declContextOrOffset =
+          PatternBindingInitializer::createDeserialized(binding, bindingIndex);
+    }
     if (!blobData.empty())
       binding->setInitStringRepresentation(bindingIndex, blobData);
     break;

lib/Serialization/Serialization.cpp

@@ -2504,11 +2504,6 @@ void Serializer::writeASTBlockEntity(const DeclContext *DC) {
       writeDefaultArgumentInitializer(DAI->getParent(), DAI->getIndex());
       return;
     }
-    case LocalDeclContextKind::PatternBindingInitializer: {
-      auto PBI = cast<SerializedPatternBindingInitializer>(local);
-      writePatternBindingInitializer(PBI->getBinding(), PBI->getBindingIndex());
-      return;
-    }
     case LocalDeclContextKind::TopLevelCodeDecl: {
       auto abbrCode = DeclTypeAbbrCodes[TopLevelCodeDeclContextLayout::Code];
       TopLevelCodeDeclContextLayout::emitRecord(Out, ScratchRecord,

test/TypeDecoder/generic_local_types.swift

@@ -175,7 +175,7 @@ class Generic<T> {
 // DEMANGLE-DECL: $s19generic_local_types7GenericCfd7Alias15L_a
 // DEMANGLE-DECL: $s19generic_local_types7GenericC6methodyySiF6nestedL_yylF5AliasL_a
 
-// CHECK-DECL: generic_local_types.(file).Generic.local context.local context.Alias1
+// CHECK-DECL: generic_local_types.(file).Generic.pattern binding initializer.local context.Alias1
 // CHECK-DECL: generic_local_types.(file).Generic.<anonymous>.Alias2
 // CHECK-DECL: generic_local_types.(file).Generic.<anonymous>.Alias3
 // CHECK-DECL: generic_local_types.(file).Generic.<anonymous>.Alias4
@@ -190,4 +190,4 @@ class Generic<T> {
 // CHECK-DECL: generic_local_types.(file).Generic.method(_:).Alias13
 // CHECK-DECL: generic_local_types.(file).Generic.init().Alias14
 // CHECK-DECL: generic_local_types.(file).Generic.deinit.Alias15
-// CHECK-DECL: generic_local_types.(file).Generic.method(_:).nested().Alias
+// CHECK-DECL: generic_local_types.(file).Generic.method(_:).nested().Alias