Merge remote-tracking branch 'origin/master' into master-rebranch

Author: swift-ci

include/swift/AST/ASTScope.h

@@ -177,8 +177,10 @@ class ASTScopeImpl {
   void addChild(ASTScopeImpl *child, ASTContext &);
   std::vector<ASTScopeImpl *> rescueYoungestChildren(unsigned count);
 
-  virtual std::vector<ASTScopeImpl *> rescueScopesToReuse();
-  virtual void addReusedScopes(ArrayRef<ASTScopeImpl *>);
+  /// When reexpanding, do we always create a new body?
+  virtual NullablePtr<ASTScopeImpl> getParentOfRescuedScopes();
+  std::vector<ASTScopeImpl *> rescueScopesToReuse();
+  void addReusedScopes(ArrayRef<ASTScopeImpl *>);
 
 private:
   void removeChildren();
@@ -201,7 +203,8 @@ class ASTScopeImpl {
   /// InterpolatedStringLiteralExprs and EditorPlaceHolders respond to
   /// getSourceRange with the starting point. But we might be asked to lookup an
   /// identifer within one of them. So, find the real source range of them here.
-  ///   /// FIXME: Alter how these are parsed so getSourceRange is enough.
+  ///
+  /// FIXME: Alter how these are parsed so getSourceRange is enough.
   SourceRange getEffectiveSourceRange(ASTNode) const;
 
   void cacheSourceRangeOfMeAndDescendants(bool omitAssertions = false) const;
@@ -303,6 +306,12 @@ class ASTScopeImpl {
   virtual void beCurrent();
   virtual bool isCurrent() const;
 
+  /// Some scopes can be expanded lazily.
+  /// Such scopes must: not change their source ranges after expansion, and
+  /// their expansion must return an insertion point outside themselves.
+  virtual NullablePtr<ASTScopeImpl> insertionPointForDeferredExpansion();
+  virtual SourceRange sourceRangeForDeferredExpansion() const;
+
 public:
   // Some nodes (VarDecls and Accessors) are created directly from
   // pattern scope code and should neither be deferred nor should
@@ -548,6 +557,10 @@ class Portion {
 
   virtual void beCurrent(IterableTypeScope *) const;
   virtual bool isCurrent(const IterableTypeScope *) const;
+  virtual NullablePtr<ASTScopeImpl>
+  insertionPointForDeferredExpansion(IterableTypeScope *) const;
+  virtual SourceRange
+  sourceRangeForDeferredExpansion(const IterableTypeScope *) const;
   };
 
   // For the whole Decl scope of a GenericType or an Extension
@@ -623,6 +636,10 @@ class IterableTypeBodyPortion final
 
   void beCurrent(IterableTypeScope *) const override;
   bool isCurrent(const IterableTypeScope *) const override;
+  NullablePtr<ASTScopeImpl>
+  insertionPointForDeferredExpansion(IterableTypeScope *) const override;
+  SourceRange
+  sourceRangeForDeferredExpansion(const IterableTypeScope *) const override;
 };
 
 /// GenericType or Extension scope
@@ -702,7 +719,6 @@ class IterableTypeScope : public GenericTypeScope {
   /// Because of \c parseDelayedDecl members can get added after the tree is
   /// constructed, and they can be out of order. Detect this happening by
   /// remembering the member count.
-  /// TODO: unify with \c numberOfDeclsAlreadySeen
   unsigned memberCount = 0;
 
 public:
@@ -721,6 +737,8 @@ class IterableTypeScope : public GenericTypeScope {
 public:
   void makeBodyCurrent();
   bool isBodyCurrent() const;
+  NullablePtr<ASTScopeImpl> insertionPointForDeferredExpansion() override;
+  SourceRange sourceRangeForDeferredExpansion() const override;
 };
 
 class NominalTypeScope final : public IterableTypeScope {
@@ -958,8 +976,7 @@ class AbstractFunctionBodyScope : public ASTScopeImpl {
   Decl *getDecl() const { return decl; }
   static bool isAMethod(const AbstractFunctionDecl *);
 
-  std::vector<ASTScopeImpl *> rescueScopesToReuse() override;
-  void addReusedScopes(ArrayRef<ASTScopeImpl *>) override;
+  NullablePtr<ASTScopeImpl> getParentOfRescuedScopes() override;
 
 protected:
   bool lookupLocalsOrMembers(ArrayRef<const ASTScopeImpl *>,
@@ -1122,7 +1139,6 @@ class PatternEntryDeclScope final : public AbstractPatternEntryScope {
   SourceRange
   getChildlessSourceRange(bool omitAssertions = false) const override;
 
-  static bool isHandledSpecially(const ASTNode n);
   NullablePtr<const void> getReferrent() const override;
 
 protected:
@@ -1372,8 +1388,7 @@ class TopLevelCodeScope final : public ASTScopeImpl {
   Decl *getDecl() const { return decl; }
   NullablePtr<const void> getReferrent() const override;
 
-  std::vector<ASTScopeImpl *> rescueScopesToReuse() override;
-  void addReusedScopes(ArrayRef<ASTScopeImpl *>) override;
+  NullablePtr<ASTScopeImpl> getParentOfRescuedScopes() override;
 };
 
 /// The \c _@specialize attribute.

include/swift/Basic/LangOptions.h

@@ -268,6 +268,9 @@ namespace swift {
     /// whether it is. The warning is useful for testing.
     bool WarnIfASTScopeLookup = false;
 
+    /// Build the ASTScope tree lazily
+    bool LazyASTScopes = false;
+
     /// Whether to use the import as member inference system
     ///
     /// When importing a global, try to infer whether we can import it as a

include/swift/Option/FrontendOptions.td

@@ -127,6 +127,9 @@ def compare_to_astscope_lookup : Flag<["-"], "compare-to-astscope-lookup">,
 
 def warn_if_astscope_lookup : Flag<["-"], "warn-if-astscope-lookup">,
   HelpText<"Print a warning if ASTScope lookup is used">;
+  
+def lazy_astscopes : Flag<["-"], "lazy-astscopes">,
+  HelpText<"Build ASTScopes lazily">;
 
 def print_clang_stats : Flag<["-"], "print-clang-stats">,
   HelpText<"Print Clang importer statistics">;