[CodeCompletion] Split result delivery into a result colleciton and consumer phase

This will allow us to run two different completion kinds and deliver results from both of them.

Also: Compute a unified type context for global lookup. Previously, we always used the expected type context of the last lookup. But really, we should be considering all possible types from all constraint system solutions when computing code completion results from the cache.

Author: ahoppen

include/swift/IDE/AfterPoundExprCompletion.h

@@ -47,8 +47,7 @@ class AfterPoundExprCompletion : public TypeCheckCompletionCallback {
       : CompletionExpr(CompletionExpr), DC(DC), ParentStmtKind(ParentStmtKind) {
   }
 
-  void deliverResults(ide::CodeCompletionContext &CompletionCtx,
-                      CodeCompletionConsumer &Consumer);
+  void collectResults(ide::CodeCompletionContext &CompletionCtx);
 };
 
 } // end namespace ide

include/swift/IDE/ArgumentCompletion.h

@@ -93,9 +93,8 @@ class ArgumentTypeCheckCompletionCallback : public TypeCheckCompletionCallback {
   /// function signature instead of suggesting individual labels. Used when
   /// completing after the opening '(' of a function call \param Loc The
   /// location of the code completion token
-  void deliverResults(bool IncludeSignature, SourceLoc Loc, DeclContext *DC,
-                      CodeCompletionContext &CompletionCtx,
-                      CodeCompletionConsumer &Consumer);
+  void collectResults(bool IncludeSignature, SourceLoc Loc, DeclContext *DC,
+                      CodeCompletionContext &CompletionCtx);
 };
 
 } // end namespace ide

include/swift/IDE/CodeCompletion.h

@@ -65,9 +65,10 @@ void postProcessCompletionResults(
     MutableArrayRef<CodeCompletionResult *> results, CompletionKind Kind,
     const DeclContext *DC, CodeCompletionResultSink *Sink);
 
-void deliverCompletionResults(CodeCompletionContext &CompletionContext,
+void collectCompletionResults(CodeCompletionContext &CompletionContext,
                               CompletionLookup &Lookup, DeclContext *DC,
-                              CodeCompletionConsumer &Consumer);
+                              const ExpectedTypeContext &TypeContext,
+                              bool CanCurrDeclContextHandleAsync);
 
 /// Create a factory for code completion callbacks.
 IDEInspectionCallbacksFactory *

include/swift/IDE/CodeCompletionConsumer.h

@@ -22,30 +22,9 @@ namespace ide {
 struct RequestedCachedModule;
 
 /// An abstract base class for consumers of code completion results.
-/// \see \c SimpleCachingCodeCompletionConsumer.
 class CodeCompletionConsumer {
 public:
   virtual ~CodeCompletionConsumer() {}
-  virtual void
-  handleResultsAndModules(CodeCompletionContext &context,
-                          ArrayRef<RequestedCachedModule> requestedModules,
-                          const ExpectedTypeContext *TypeContext,
-                          const DeclContext *DC,
-                          bool CanCurrDeclContextHandleAsync) = 0;
-};
-
-/// A simplified code completion consumer interface that clients can use to get
-/// CodeCompletionResults with automatic caching of top-level completions from
-/// imported modules.
-struct SimpleCachingCodeCompletionConsumer : public CodeCompletionConsumer {
-
-  // Implement the CodeCompletionConsumer interface.
-  void handleResultsAndModules(CodeCompletionContext &context,
-                               ArrayRef<RequestedCachedModule> requestedModules,
-                               const ExpectedTypeContext *TypeContext,
-                               const DeclContext *DCForModules,
-                               bool CanCurrDeclContextHandleAsync) override;
-
   /// Clients should override this method to receive \p Results.
   virtual void handleResults(CodeCompletionContext &context) = 0;
 };

include/swift/IDE/CodeCompletionContext.h

@@ -20,6 +20,7 @@ namespace swift {
 namespace ide {
 
 class CodeCompletionCache;
+struct RequestedCachedModule;
 
 class CodeCompletionContext {
   friend class CodeCompletionResultBuilder;
@@ -103,6 +104,13 @@ class CodeCompletionContext {
   sortCompletionResults(ArrayRef<CodeCompletionResult *> Results);
 
   CodeCompletionResultSink &getResultSink() { return CurrentResults; }
+
+  /// Add code completion results from the given requested modules to this
+  /// context.
+  void addResultsFromModules(ArrayRef<RequestedCachedModule> RequestedModules,
+                             const ExpectedTypeContext &TypeContext,
+                             const DeclContext *DC,
+                             bool CanCurrDeclContextHandleAsync);
 };
 
 } // end namespace ide

include/swift/IDE/CodeCompletionResultType.h

@@ -74,6 +74,26 @@ class ExpectedTypeContext {
     }
   }
 
+  /// Form a union of this expected type context with \p Other.
+  ///
+  /// Any possible type from either type context will be considered a possible
+  /// type in the merged type context.
+  void merge(const ExpectedTypeContext &Other) {
+    PossibleTypes.append(Other.PossibleTypes);
+
+    // We can't merge ideal types. Setting to a null type is the best thing we
+    // can do if they differ.
+    if (IdealType.isNull() != Other.IdealType.isNull()) {
+      IdealType = Type();
+    } else if (IdealType && Other.IdealType &&
+               !IdealType->isEqual(Other.IdealType)) {
+      IdealType = Type();
+    }
+    IsImplicitSingleExpressionReturn |= Other.IsImplicitSingleExpressionReturn;
+    PreferNonVoid &= Other.PreferNonVoid;
+    ExpectedCustomAttributeKinds |= Other.ExpectedCustomAttributeKinds;
+  }
+
   Type getIdealType() const { return IdealType; }
 
   void setIdealType(Type IdealType) { this->IdealType = IdealType; }

include/swift/IDE/ExprCompletion.h

@@ -90,9 +90,8 @@ class ExprTypeCheckCompletionCallback : public TypeCheckCompletionCallback {
         AddUnresolvedMemberCompletions(AddUnresolvedMemberCompletions) {}
 
   /// \param CCLoc The location of the code completion token.
-  void deliverResults(SourceLoc CCLoc,
-                      ide::CodeCompletionContext &CompletionCtx,
-                      CodeCompletionConsumer &Consumer);
+  void collectResults(SourceLoc CCLoc,
+                      ide::CodeCompletionContext &CompletionCtx);
 };
 
 } // end namespace ide

include/swift/IDE/KeyPathCompletion.h

@@ -37,9 +37,8 @@ class KeyPathTypeCheckCompletionCallback : public TypeCheckCompletionCallback {
 public:
   KeyPathTypeCheckCompletionCallback(KeyPathExpr *KeyPath) : KeyPath(KeyPath) {}
 
-  void deliverResults(DeclContext *DC, SourceLoc DotLoc,
-                      ide::CodeCompletionContext &CompletionCtx,
-                      CodeCompletionConsumer &Consumer);
+  void collectResults(DeclContext *DC, SourceLoc DotLoc,
+                      ide::CodeCompletionContext &CompletionCtx);
 };
 
 } // end namespace ide

include/swift/IDE/PostfixCompletion.h

@@ -103,10 +103,9 @@ class PostfixCompletionCallback : public TypeCheckCompletionCallback {
   ///                         \p DotLoc is invalid
   /// \param HasLeadingSpace Whether there is a space separating the exiting
   ///                        expression and the code completion token.
-  void deliverResults(SourceLoc DotLoc, bool IsInSelector,
+  void collectResults(SourceLoc DotLoc, bool IsInSelector,
                       bool IncludeOperators, bool HasLeadingSpace,
-                      CodeCompletionContext &CompletionCtx,
-                      CodeCompletionConsumer &Consumer);
+                      CodeCompletionContext &CompletionCtx);
 };
 
 } // end namespace ide

include/swift/IDE/UnresolvedMemberCompletion.h

@@ -59,9 +59,8 @@ class UnresolvedMemberTypeCheckCompletionCallback
       CodeCompletionExpr *CompletionExpr, DeclContext *DC)
       : CompletionExpr(CompletionExpr), DC(DC) {}
 
-  void deliverResults(DeclContext *DC, SourceLoc DotLoc,
-                      ide::CodeCompletionContext &CompletionCtx,
-                      CodeCompletionConsumer &Consumer);
+  void collectResults(DeclContext *DC, SourceLoc DotLoc,
+                      ide::CodeCompletionContext &CompletionCtx);
 };
 
 } // end namespace ide