[AST] A couple of PatternBindingInitializer cleanups

include/swift/AST/Decl.h

@@ -31,6 +31,7 @@
 #include "swift/AST/GenericParamKey.h"
 #include "swift/AST/IfConfigClause.h"
 #include "swift/AST/Import.h"
+#include "swift/AST/Initializer.h"
 #include "swift/AST/LayoutConstraint.h"
 #include "swift/AST/LifetimeAnnotation.h"
 #include "swift/AST/ReferenceCounting.h"
@@ -1962,7 +1963,7 @@ class PatternBindingEntry {
     IsFromDebugger = 1 << 2,
   };
   /// The initializer context used for this pattern binding entry.
-  llvm::PointerIntPair<DeclContext *, 3, OptionSet<PatternFlags>>
+  llvm::PointerIntPair<PatternBindingInitializer *, 3, OptionSet<PatternFlags>>
       InitContextAndFlags;
 
   /// Values captured by this initializer.
@@ -2003,7 +2004,7 @@ class PatternBindingEntry {
 public:
   /// \p E is the initializer as parsed.
   PatternBindingEntry(Pattern *P, SourceLoc EqualLoc, Expr *E,
-                      DeclContext *InitContext)
+                      PatternBindingInitializer *InitContext)
       : PatternAndFlags(P, {}),
         InitExpr({E, {E, InitializerStatus::NotChecked}, EqualLoc}),
         InitContextAndFlags({InitContext, llvm::None}) {}
@@ -2107,12 +2108,14 @@ class PatternBindingEntry {
   VarDecl *getAnchoringVarDecl() const;
 
   // Retrieve the declaration context for the initializer.
-  DeclContext *getInitContext() const {
+  PatternBindingInitializer *getInitContext() const {
     return InitContextAndFlags.getPointer();
   }
 
   /// Override the initializer context.
-  void setInitContext(DeclContext *dc) { InitContextAndFlags.setPointer(dc); }
+  void setInitContext(PatternBindingInitializer *init) {
+    InitContextAndFlags.setPointer(init);
+  }
 
   SourceLoc getStartLoc() const;
 
@@ -2310,18 +2313,24 @@ class PatternBindingDecl final : public Decl,
   Pattern *getPattern(unsigned i) const {
     return getPatternList()[i].getPattern();
   }
-
-  void setPattern(unsigned i, Pattern *Pat, DeclContext *InitContext,
-                  bool isFullyValidated = false);
+
+  void setPattern(unsigned i, Pattern *P, bool isFullyValidated = false);
 
   bool isFullyValidated(unsigned i) const {
     return getPatternList()[i].isFullyValidated();
   }
 
-  DeclContext *getInitContext(unsigned i) const {
+  PatternBindingInitializer *getInitContext(unsigned i) const {
     return getPatternList()[i].getInitContext();
   }
 
+  void setInitContext(unsigned i, PatternBindingInitializer *init) {
+    if (init) {
+      init->setBinding(this, i);
+    }
+    getMutablePatternList()[i].setInitContext(init);
+  }
+
   CaptureInfo getCaptureInfo(unsigned i) const {
     return getPatternList()[i].getCaptureInfo();
   }

include/swift/AST/DeclContext.h

@@ -79,8 +79,6 @@ namespace swift {
   class Initializer;
   class ClassDecl;
   class SerializedAbstractClosureExpr;
-  class SerializedPatternBindingInitializer;
-  class SerializedDefaultArgumentInitializer;
   class SerializedTopLevelCodeDecl;
   class StructDecl;
   class AccessorDecl;
@@ -115,8 +113,6 @@ enum class DeclContextKind : unsigned {
 /// \see SerializedLocalDeclContext.
 enum class LocalDeclContextKind : uint8_t {
   AbstractClosure,
-  PatternBindingInitializer,
-  DefaultArgumentInitializer,
   TopLevelCodeDecl
 };
 

include/swift/AST/Initializer.h

@@ -21,9 +21,9 @@
 #define SWIFT_INITIALIZER_H
 
 #include "swift/AST/DeclContext.h"
-#include "swift/AST/Decl.h"
 
 namespace swift {
+class ParamDecl;
 class PatternBindingDecl;
 
 enum class InitializerKind : uint8_t {
@@ -76,28 +76,25 @@ class PatternBindingInitializer : public Initializer {
   // created lazily for 'self' lookup from lazy property initializer
   ParamDecl *SelfParam;
 
-  friend class ASTContext; // calls reset on unused contexts
+  // Sets itself as the parent.
+  friend class PatternBindingDecl;
 
-  void reset(DeclContext *parent) {
-    setParent(parent);
-    Binding = nullptr;
-    SelfParam = nullptr;
-  }
+  void setBinding(PatternBindingDecl *binding, unsigned bindingIndex);
 
-public:
   explicit PatternBindingInitializer(DeclContext *parent)
     : Initializer(InitializerKind::PatternBinding, parent),
       Binding(nullptr), SelfParam(nullptr) {
     SpareBits = 0;
   }
-
 
-  void setBinding(PatternBindingDecl *binding, unsigned bindingIndex) {
-    setParent(binding->getDeclContext());
-    Binding = binding;
-    SpareBits = bindingIndex;
+public:
+  static PatternBindingInitializer *create(DeclContext *parent) {
+    return new (parent->getASTContext()) PatternBindingInitializer(parent);
   }
-
+
+  static PatternBindingInitializer *createDeserialized(PatternBindingDecl *PBD,
+                                                       unsigned index);
+
   PatternBindingDecl *getBinding() const { return Binding; }
 
   unsigned getBindingIndex() const { return SpareBits; }
@@ -119,37 +116,6 @@ 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 {
@@ -176,29 +142,6 @@ class DefaultArgumentInitializer : public Initializer {
   }
 };
 
-/// SerializedDefaultArgumentInitializer - This represents what was originally a
-/// DefaultArgumentInitializer during serialization. It is preserved only to
-/// maintain the correct AST structure and remangling after deserialization.
-class SerializedDefaultArgumentInitializer : public SerializedLocalDeclContext {
-  const unsigned Index;
-public:
-  SerializedDefaultArgumentInitializer(unsigned Index, DeclContext *Parent)
-    : SerializedLocalDeclContext(LocalDeclContextKind::DefaultArgumentInitializer,
-                                 Parent),
-      Index(Index) {}
-
-  unsigned getIndex() const {
-    return Index;
-  }
-
-  static bool classof(const DeclContext *DC) {
-    if (auto LDC = dyn_cast<SerializedLocalDeclContext>(DC))
-      return LDC->getLocalDeclContextKind() ==
-        LocalDeclContextKind::DefaultArgumentInitializer;
-    return false;
-  }
-};
-
 /// A property wrapper initialization expression.  The parent context is the
 /// function or closure which owns the property wrapper.
 class PropertyWrapperInitializer : public Initializer {

include/swift/Sema/SyntacticElementTarget.h

@@ -254,7 +254,7 @@ class SyntacticElementTarget {
   /// Form a target for the initialization of a pattern binding entry from
   /// an expression.
   static SyntacticElementTarget
-  forInitialization(Expr *initializer, DeclContext *dc, Type patternType,
+  forInitialization(Expr *initializer, Type patternType,
                     PatternBindingDecl *patternBinding,
                     unsigned patternBindingIndex, bool bindPatternVarsOneWay);
 

lib/AST/ASTBridging.cpp

@@ -343,8 +343,7 @@ bool BridgedDeclContext_isLocalContext(BridgedDeclContext cDeclContext) {
 
 BridgedPatternBindingInitializer
 BridgedPatternBindingInitializer_create(BridgedDeclContext cDeclContext) {
-  auto *dc = cDeclContext.unbridged();
-  return new (dc->getASTContext()) PatternBindingInitializer(dc);
+  return PatternBindingInitializer::create(cDeclContext.unbridged());
 }
 
 BridgedDeclContext BridgedPatternBindingInitializer_asDeclContext(

lib/AST/ASTMangler.cpp

@@ -2323,22 +2323,6 @@ void ASTMangler::appendContext(const DeclContext *ctx, StringRef useModuleName)
     case LocalDeclContextKind::AbstractClosure:
       appendClosureEntity(cast<SerializedAbstractClosureExpr>(local));
       return;
-    case LocalDeclContextKind::DefaultArgumentInitializer: {
-      auto argInit = cast<SerializedDefaultArgumentInitializer>(local);
-      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/ASTScopeLookup.cpp

@@ -437,9 +437,7 @@ bool BraceStmtScope::lookupLocalsOrMembers(DeclConsumer consumer) const {
 bool PatternEntryInitializerScope::lookupLocalsOrMembers(
     DeclConsumer consumer) const {
   // 'self' is available within the pattern initializer of a 'lazy' variable.
-  auto *initContext = dyn_cast_or_null<PatternBindingInitializer>(
-      decl->getInitContext(0));
-  if (initContext) {
+  if (auto *initContext = decl->getInitContext(0)) {
     if (auto *selfParam = initContext->getImplicitSelfDecl()) {
       return consumer.consume({selfParam});
     }

lib/AST/ASTWalker.cpp

@@ -202,7 +202,7 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
 
     for (auto idx : range(PBD->getNumPatternEntries())) {
       if (Pattern *Pat = doIt(PBD->getPattern(idx)))
-        PBD->setPattern(idx, Pat, PBD->getInitContext(idx));
+        PBD->setPattern(idx, Pat);
       else
         return true;
 

lib/AST/Decl.cpp

@@ -1924,21 +1924,19 @@ PatternBindingDecl::create(ASTContext &Ctx, SourceLoc StaticLoc,
                           PBD->getTrailingObjects<PatternBindingEntry>());
 
   for (auto idx : range(PBD->getNumPatternEntries())) {
-    auto *initContext =
-        cast_or_null<PatternBindingInitializer>(PBD->getInitContext(idx));
+    auto *initContext = PBD->getInitContext(idx);
 
     // FIXME: We ought to reconsider this since it won't recontextualize any
     // closures/decls present in the initialization expr. This currently should
     // only affect implicit code though.
     if (!initContext && !Parent->isLocalContext())
-      initContext = new (Ctx) PatternBindingInitializer(Parent);
-
-    if (initContext)
-      initContext->setBinding(PBD, idx);
+      initContext = PatternBindingInitializer::create(Parent);
 
     // We need to call setPattern to ensure the VarDecls in the pattern have
-    // the PatternBindingDecl set as their parent, and to setup the context.
-    PBD->setPattern(idx, PBD->getPattern(idx), initContext);
+    // the PatternBindingDecl set as their parent. We also need to call
+    // setInitContext to setup the context.
+    PBD->setPattern(idx, PBD->getPattern(idx));
+    PBD->setInitContext(idx, initContext);
   }
   return PBD;
 }
@@ -1961,6 +1959,14 @@ 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;
@@ -1996,6 +2002,18 @@ ParamDecl *PatternBindingInitializer::getImplicitSelfDecl() const {
   return SelfParam;
 }
 
+void PatternBindingInitializer::setBinding(PatternBindingDecl *binding,
+                                           unsigned bindingIndex) {
+  assert(binding);
+  assert(!Binding || Binding == binding &&
+         "Cannot change the binding after the fact");
+  assert(!Binding || SpareBits == bindingIndex &&
+         "Cannot change the binding index after the fact");
+  setParent(binding->getDeclContext());
+  Binding = binding;
+  SpareBits = bindingIndex;
+}
+
 VarDecl *PatternBindingInitializer::getInitializedLazyVar() const {
   if (auto binding = getBinding()) {
     if (auto var = binding->getSingleVar()) {
@@ -2224,12 +2242,10 @@ PatternBindingDecl::getCheckedPatternBindingEntry(unsigned i) const {
 }
 
 void PatternBindingDecl::setPattern(unsigned i, Pattern *P,
-                                    DeclContext *InitContext,
                                     bool isFullyValidated) {
   auto PatternList = getMutablePatternList();
   PatternList[i].setPattern(P);
-  PatternList[i].setInitContext(InitContext);
-
+
   // Make sure that any VarDecl's contained within the pattern know about this
   // PatternBindingDecl as their parent.
   if (P) {
@@ -2243,7 +2259,6 @@ void PatternBindingDecl::setPattern(unsigned i, Pattern *P,
   }
 }
 
-
 VarDecl *PatternBindingDecl::getSingleVar() const {
   if (getNumPatternEntries() == 1)
     return getPatternList()[0].getPattern()->getSingleVar();

lib/AST/DeclContext.cpp

@@ -824,17 +824,6 @@ unsigned DeclContext::printContext(raw_ostream &OS, const unsigned indent,
       OS << " closure : " << serializedClosure->getType();
       break;
     }
-    case LocalDeclContextKind::DefaultArgumentInitializer: {
-      auto init = cast<SerializedDefaultArgumentInitializer>(local);
-      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;