9 files changed, 393 insertions, 136 deletions

diff --git a/include/clang/Parse/Parser.h b/include/clang/Parse/Parser.h
index 93a6582dcf..e6e2bc3652 100644
--- a/include/clang/Parse/Parser.h
+++ b/include/clang/Parse/Parser.h
@@ -74,6 +74,10 @@ class Parser : public CodeCompletionHandler {
   // a statement).
   SourceLocation PrevTokLocation;
 
+  /// Tracks an expected type for the current token when parsing an expression.
+  /// Used by code completion for ranking.
+  PreferredTypeBuilder PreferredType;
+
   unsigned short ParenCount = 0, BracketCount = 0, BraceCount = 0;
   unsigned short MisplacedModuleBeginCount = 0;
 
@@ -840,6 +844,7 @@ private:
   ///
   class TentativeParsingAction {
     Parser &P;
+    PreferredTypeBuilder PrevPreferredType;
     Token PrevTok;
     size_t PrevTentativelyDeclaredIdentifierCount;
     unsigned short PrevParenCount, PrevBracketCount, PrevBraceCount;
@@ -847,6 +852,7 @@ private:
 
   public:
     explicit TentativeParsingAction(Parser& p) : P(p) {
+      PrevPreferredType = P.PreferredType;
       PrevTok = P.Tok;
       PrevTentativelyDeclaredIdentifierCount =
           P.TentativelyDeclaredIdentifiers.size();
@@ -866,6 +872,7 @@ private:
     void Revert() {
       assert(isActive && "Parsing action was finished!");
       P.PP.Backtrack();
+      P.PreferredType = PrevPreferredType;
       P.Tok = PrevTok;
       P.TentativelyDeclaredIdentifiers.resize(
           PrevTentativelyDeclaredIdentifierCount);
diff --git a/include/clang/Sema/CodeCompleteConsumer.h b/include/clang/Sema/CodeCompleteConsumer.h
index 5c14fb8773..72ba8bf31d 100644
--- a/include/clang/Sema/CodeCompleteConsumer.h
+++ b/include/clang/Sema/CodeCompleteConsumer.h
@@ -380,6 +380,7 @@ public:
   /// if the expression is a variable initializer or a function argument, the
   /// type of the corresponding variable or function parameter.
   QualType getPreferredType() const { return PreferredType; }
+  void setPreferredType(QualType T) { PreferredType = T; }
 
   /// Retrieve the type of the base object in a member-access
   /// expression.
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 59339b8e16..dc70a8b04a 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -273,6 +273,41 @@ public:
   }
 };
 
+/// Keeps track of expected type during expression parsing. The type is tied to
+/// a particular token, all functions that update or consume the type take a
+/// start location of the token they are looking at as a parameter. This allows
+/// to avoid updating the type on hot paths in the parser.
+class PreferredTypeBuilder {
+public:
+  PreferredTypeBuilder() = default;
+  explicit PreferredTypeBuilder(QualType Type) : Type(Type) {}
+
+  void enterCondition(Sema &S, SourceLocation Tok);
+  void enterReturn(Sema &S, SourceLocation Tok);
+  void enterVariableInit(SourceLocation Tok, Decl *D);
+
+  void enterParenExpr(SourceLocation Tok, SourceLocation LParLoc);
+  void enterUnary(Sema &S, SourceLocation Tok, tok::TokenKind OpKind,
+                  SourceLocation OpLoc);
+  void enterBinary(Sema &S, SourceLocation Tok, Expr *LHS, tok::TokenKind Op);
+  void enterMemAccess(Sema &S, SourceLocation Tok, Expr *Base);
+  void enterSubscript(Sema &S, SourceLocation Tok, Expr *LHS);
+  /// Handles all type casts, including C-style cast, C++ casts, etc.
+  void enterTypeCast(SourceLocation Tok, QualType CastType);
+
+  QualType get(SourceLocation Tok) const {
+    if (Tok == ExpectedLoc)
+      return Type;
+    return QualType();
+  }
+
+private:
+  /// Start position of a token for which we store expected type.
+  SourceLocation ExpectedLoc;
+  /// Expected type for a token starting at ExpectedLoc.
+  QualType Type;
+};
+
 /// Sema - This implements semantic analysis and AST building for C.
 class Sema {
   Sema(const Sema &) = delete;
@@ -10371,11 +10406,14 @@ public:
   struct CodeCompleteExpressionData;
   void CodeCompleteExpression(Scope *S,
                               const CodeCompleteExpressionData &Data);
-  void CodeCompleteExpression(Scope *S, QualType PreferredType);
+  void CodeCompleteExpression(Scope *S, QualType PreferredType,
+                              bool IsParenthesized = false);
   void CodeCompleteMemberReferenceExpr(Scope *S, Expr *Base, Expr *OtherOpBase,
                                        SourceLocation OpLoc, bool IsArrow,
-                                       bool IsBaseExprStatement);
-  void CodeCompletePostfixExpression(Scope *S, ExprResult LHS);
+                                       bool IsBaseExprStatement,
+                                       QualType PreferredType);
+  void CodeCompletePostfixExpression(Scope *S, ExprResult LHS,
+                                     QualType PreferredType);
   void CodeCompleteTag(Scope *S, unsigned TagSpec);
   void CodeCompleteTypeQualifiers(DeclSpec &DS);
   void CodeCompleteFunctionQualifiers(DeclSpec &DS, Declarator &D,
@@ -10397,9 +10435,7 @@ public:
                                               IdentifierInfo *II,
                                               SourceLocation OpenParLoc);
   void CodeCompleteInitializer(Scope *S, Decl *D);
-  void CodeCompleteReturn(Scope *S);
   void CodeCompleteAfterIf(Scope *S);
-  void CodeCompleteBinaryRHS(Scope *S, Expr *LHS, tok::TokenKind Op);
 
   void CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS,
                                bool EnteringContext, QualType BaseType);
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index bbead42f03..a3080e64b0 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -2293,7 +2293,8 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
         return nullptr;
       }
 
-      ExprResult Init(ParseInitializer());
+      PreferredType.enterVariableInit(Tok.getLocation(), ThisDecl);
+      ExprResult Init = ParseInitializer();
 
       // If this is the only decl in (possibly) range based for statement,
       // our best guess is that the user meant ':' instead of '='.
diff --git a/lib/Parse/ParseExpr.cpp b/lib/Parse/ParseExpr.cpp
index d3787b9760..1146afd134 100644
--- a/lib/Parse/ParseExpr.cpp
+++ b/lib/Parse/ParseExpr.cpp
@@ -158,7 +158,8 @@ Parser::ParseExpressionWithLeadingExtension(SourceLocation ExtLoc) {
 /// Parse an expr that doesn't include (top-level) commas.
 ExprResult Parser::ParseAssignmentExpression(TypeCastState isTypeCast) {
   if (Tok.is(tok::code_completion)) {
-    Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Expression);
+    Actions.CodeCompleteExpression(getCurScope(),
+                                   PreferredType.get(Tok.getLocation()));
     cutOffParsing();
     return ExprError();
   }
@@ -271,7 +272,10 @@ Parser::ParseRHSOfBinaryExpression(ExprResult LHS, prec::Level MinPrec) {
                                                getLangOpts().CPlusPlus11);
   SourceLocation ColonLoc;
 
+  auto SavedType = PreferredType;
   while (1) {
+    // Every iteration may rely on a preferred type for the whole expression.
+    PreferredType = SavedType;
     // If this token has a lower precedence than we are allowed to parse (e.g.
     // because we are called recursively, or because the token is not a binop),
     // then we are done!
@@ -392,15 +396,8 @@ Parser::ParseRHSOfBinaryExpression(ExprResult LHS, prec::Level MinPrec) {
       }
     }
 
-    // Code completion for the right-hand side of a binary expression goes
-    // through a special hook that takes the left-hand side into account.
-    if (Tok.is(tok::code_completion)) {
-      Actions.CodeCompleteBinaryRHS(getCurScope(), LHS.get(),
-                                    OpToken.getKind());
-      cutOffParsing();
-      return ExprError();
-    }
-
+    PreferredType.enterBinary(Actions, Tok.getLocation(), LHS.get(),
+                              OpToken.getKind());
     // Parse another leaf here for the RHS of the operator.
     // ParseCastExpression works here because all RHS expressions in C have it
     // as a prefix, at least. However, in C++, an assignment-expression could
@@ -763,6 +760,7 @@ ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
                                        bool isVectorLiteral) {
   ExprResult Res;
   tok::TokenKind SavedKind = Tok.getKind();
+  auto SavedType = PreferredType;
   NotCastExpr = false;
 
   // This handles all of cast-expression, unary-expression, postfix-expression,
@@ -1114,6 +1112,9 @@ ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
     //     -- cast-expression
     Token SavedTok = Tok;
     ConsumeToken();
+
+    PreferredType.enterUnary(Actions, Tok.getLocation(), SavedTok.getKind(),
+                             SavedTok.getLocation());
     // One special case is implicitly handled here: if the preceding tokens are
     // an ambiguous cast expression, such as "(T())++", then we recurse to
     // determine whether the '++' is prefix or postfix.
@@ -1135,6 +1136,7 @@ ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
   case tok::amp: {         // unary-expression: '&' cast-expression
     // Special treatment because of member pointers
     SourceLocation SavedLoc = ConsumeToken();
+    PreferredType.enterUnary(Actions, Tok.getLocation(), tok::amp, SavedLoc);
     Res = ParseCastExpression(false, true);
     if (!Res.isInvalid())
       Res = Actions.ActOnUnaryOp(getCurScope(), SavedLoc, SavedKind, Res.get());
@@ -1149,6 +1151,7 @@ ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
   case tok::kw___real:     // unary-expression: '__real' cast-expression [GNU]
   case tok::kw___imag: {   // unary-expression: '__imag' cast-expression [GNU]
     SourceLocation SavedLoc = ConsumeToken();
+    PreferredType.enterUnary(Actions, Tok.getLocation(), SavedKind, SavedLoc);
     Res = ParseCastExpression(false);
     if (!Res.isInvalid())
       Res = Actions.ActOnUnaryOp(getCurScope(), SavedLoc, SavedKind, Res.get());
@@ -1423,7 +1426,8 @@ ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
     Res = ParseBlockLiteralExpression();
     break;
   case tok::code_completion: {
-    Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Expression);
+    Actions.CodeCompleteExpression(getCurScope(),
+                                   PreferredType.get(Tok.getLocation()));
     cutOffParsing();
     return ExprError();
   }
@@ -1458,6 +1462,7 @@ ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
   // that the address of the function is being taken, which is illegal in CL.
 
   // These can be followed by postfix-expr pieces.
+  PreferredType = SavedType;
   Res = ParsePostfixExpressionSuffix(Res);
   if (getLangOpts().OpenCL)
     if (Expr *PostfixExpr = Res.get()) {
@@ -1497,13 +1502,17 @@ Parser::ParsePostfixExpressionSuffix(ExprResult LHS) {
   // Now that the primary-expression piece of the postfix-expression has been
   // parsed, see if there are any postfix-expression pieces here.
   SourceLocation Loc;
+  auto SavedType = PreferredType;
   while (1) {
+    // Each iteration relies on preferred type for the whole expression.
+    PreferredType = SavedType;
     switch (Tok.getKind()) {
     case tok::code_completion:
       if (InMessageExpression)
         return LHS;
 
-      Actions.CodeCompletePostfixExpression(getCurScope(), LHS);
+      Actions.CodeCompletePostfixExpression(
+          getCurScope(), LHS, PreferredType.get(Tok.getLocation()));
       cutOffParsing();
       return ExprError();
 
@@ -1545,6 +1554,7 @@ Parser::ParsePostfixExpressionSuffix(ExprResult LHS) {
       Loc = T.getOpenLocation();
       ExprResult Idx, Length;
       SourceLocation ColonLoc;
+      PreferredType.enterSubscript(Actions, Tok.getLocation(), LHS.get());
       if (getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace)) {
         Diag(Tok, diag::warn_cxx98_compat_generalized_initializer_lists);
         Idx = ParseBraceInitializer();
@@ -1726,6 +1736,8 @@ Parser::ParsePostfixExpressionSuffix(ExprResult LHS) {
       bool MayBePseudoDestructor = false;
       Expr* OrigLHS = !LHS.isInvalid() ? LHS.get() : nullptr;
 
+      PreferredType.enterMemAccess(Actions, Tok.getLocation(), OrigLHS);
+
       if (getLangOpts().CPlusPlus && !LHS.isInvalid()) {
         Expr *Base = OrigLHS;
         const Type* BaseType = Base->getType().getTypePtrOrNull();
@@ -1772,7 +1784,8 @@ Parser::ParsePostfixExpressionSuffix(ExprResult LHS) {
         // Code completion for a member access expression.
         Actions.CodeCompleteMemberReferenceExpr(
             getCurScope(), Base, CorrectedBase, OpLoc, OpKind == tok::arrow,
-            Base && ExprStatementTokLoc == Base->getBeginLoc());
+            Base && ExprStatementTokLoc == Base->getBeginLoc(),
+            PreferredType.get(Tok.getLocation()));
 
         cutOffParsing();
         return ExprError();
@@ -2326,14 +2339,16 @@ Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr,
     return ExprError();
   SourceLocation OpenLoc = T.getOpenLocation();
 
+  PreferredType.enterParenExpr(Tok.getLocation(), OpenLoc);
+
   ExprResult Result(true);
   bool isAmbiguousTypeId;
   CastTy = nullptr;
 
   if (Tok.is(tok::code_completion)) {
-    Actions.CodeCompleteOrdinaryName(getCurScope(),
-                 ExprType >= CompoundLiteral? Sema::PCC_ParenthesizedExpression
-                                            : Sema::PCC_Expression);
+    Actions.CodeCompleteExpression(
+        getCurScope(), PreferredType.get(Tok.getLocation()),
+        /*IsParenthesized=*/ExprType >= CompoundLiteral);
     cutOffParsing();
     return ExprError();
   }
@@ -2414,6 +2429,8 @@ Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr,
     T.consumeClose();
     ColonProtection.restore();
     RParenLoc = T.getCloseLocation();
+
+    PreferredType.enterTypeCast(Tok.getLocation(), Ty.get().get());
     ExprResult SubExpr = ParseCastExpression(/*isUnaryExpression=*/false);
 
     if (Ty.isInvalid() || SubExpr.isInvalid())
@@ -2544,6 +2561,7 @@ Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr,
           return ExprError();
         }
 
+        PreferredType.enterTypeCast(Tok.getLocation(), CastTy.get());
         // Parse the cast-expression that follows it next.
         // TODO: For cast expression with CastTy.
         Result = ParseCastExpression(/*isUnaryExpression=*/false,
@@ -2845,7 +2863,8 @@ bool Parser::ParseExpressionList(SmallVectorImpl<Expr *> &Exprs,
       if (Completer)
         Completer();
       else
-        Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Expression);
+        Actions.CodeCompleteExpression(getCurScope(),
+                                       PreferredType.get(Tok.getLocation()));
       cutOffParsing();
       return true;
     }
diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index 00f369f2d7..6ef24058a1 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -1672,6 +1672,8 @@ Parser::ParseCXXTypeConstructExpression(const DeclSpec &DS) {
     BalancedDelimiterTracker T(*this, tok::l_paren);
     T.consumeOpen();
 
+    PreferredType.enterTypeCast(Tok.getLocation(), TypeRep.get());
+
     ExprVector Exprs;
     CommaLocsTy CommaLocs;
 
@@ -1739,6 +1741,7 @@ Sema::ConditionResult Parser::ParseCXXCondition(StmtResult *InitStmt,
                                                 Sema::ConditionKind CK,
                                                 ForRangeInfo *FRI) {
   ParenBraceBracketBalancer BalancerRAIIObj(*this);
+  PreferredType.enterCondition(Actions, Tok.getLocation());
 
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Condition);
@@ -1858,6 +1861,7 @@ Sema::ConditionResult Parser::ParseCXXCondition(StmtResult *InitStmt,
          diag::warn_cxx98_compat_generalized_initializer_lists);
     InitExpr = ParseBraceInitializer();
   } else if (CopyInitialization) {
+    PreferredType.enterVariableInit(Tok.getLocation(), DeclOut);
     InitExpr = ParseAssignmentExpression();
   } else if (Tok.is(tok::l_paren)) {
     // This was probably an attempt to initialize the variable.
diff --git a/lib/Parse/ParseStmt.cpp b/lib/Parse/ParseStmt.cpp
index 5eab45a702..3fc29253f0 100644
--- a/lib/Parse/ParseStmt.cpp
+++ b/lib/Parse/ParseStmt.cpp
@@ -1970,9 +1970,12 @@ StmtResult Parser::ParseReturnStatement() {
 
   ExprResult R;
   if (Tok.isNot(tok::semi)) {
+    if (!IsCoreturn)
+      PreferredType.enterReturn(Actions, Tok.getLocation());
     // FIXME: Code completion for co_return.
     if (Tok.is(tok::code_completion) && !IsCoreturn) {
-      Actions.CodeCompleteReturn(getCurScope());
+      Actions.CodeCompleteExpression(getCurScope(),
+                                     PreferredType.get(Tok.getLocation()));
       cutOffParsing();
       return StmtError();
     }
diff --git a/lib/Sema/SemaCodeComplete.cpp b/lib/Sema/SemaCodeComplete.cpp
index a88e15cb55..03d612a3e9 100644
--- a/lib/Sema/SemaCodeComplete.cpp
+++ b/lib/Sema/SemaCodeComplete.cpp
@@ -347,6 +347,182 @@ public:
 };
 } // namespace
 
+void PreferredTypeBuilder::enterReturn(Sema &S, SourceLocation Tok) {
+  if (isa<BlockDecl>(S.CurContext)) {
+    if (sema::BlockScopeInfo *BSI = S.getCurBlock()) {
+      Type = BSI->ReturnType;
+      ExpectedLoc = Tok;
+    }
+  } else if (const auto *Function = dyn_cast<FunctionDecl>(S.CurContext)) {
+    Type = Function->getReturnType();
+    ExpectedLoc = Tok;
+  } else if (const auto *Method = dyn_cast<ObjCMethodDecl>(S.CurContext)) {
+    Type = Method->getReturnType();
+    ExpectedLoc = Tok;
+  }
+}
+
+void PreferredTypeBuilder::enterVariableInit(SourceLocation Tok, Decl *D) {
+  auto *VD = llvm::dyn_cast_or_null<ValueDecl>(D);
+  Type = VD ? VD->getType() : QualType();
+  ExpectedLoc = Tok;
+}
+
+void PreferredTypeBuilder::enterParenExpr(SourceLocation Tok,
+                                          SourceLocation LParLoc) {
+  // expected type for parenthesized expression does not change.
+  if (ExpectedLoc == LParLoc)
+    ExpectedLoc = Tok;
+}
+
+static QualType getPreferredTypeOfBinaryRHS(Sema &S, Expr *LHS,
+                                            tok::TokenKind Op) {
+  if (!LHS)
+    return QualType();
+
+  QualType LHSType = LHS->getType();
+  if (LHSType->isPointerType()) {
+    if (Op == tok::plus || Op == tok::plusequal || Op == tok::minusequal)
+      return S.getASTContext().getPointerDiffType();
+    // Pointer difference is more common than subtracting an int from a pointer.
+    if (Op == tok::minus)
+      return LHSType;
+  }
+
+  switch (Op) {
+  // No way to infer the type of RHS from LHS.
+  case tok::comma:
+    return QualType();
+  // Prefer the type of the left operand for all of these.
+  // Arithmetic operations.
+  case tok::plus:
+  case tok::plusequal:
+  case tok::minus:
+  case tok::minusequal:
+  case tok::percent:
+  case tok::percentequal:
+  case tok::slash:
+  case tok::slashequal:
+  case tok::star:
+  case tok::starequal:
+  // Assignment.
+  case tok::equal:
+  // Comparison operators.
+  case tok::equalequal:
+  case tok::exclaimequal:
+  case tok::less:
+  case tok::lessequal:
+  case tok::greater:
+  case tok::greaterequal:
+  case tok::spaceship:
+    return LHS->getType();
+  // Binary shifts are often overloaded, so don't try to guess those.
+  case tok::greatergreater:
+  case tok::greatergreaterequal:
+  case tok::lessless:
+  case tok::lesslessequal:
+    if (LHSType->isIntegralOrEnumerationType())
+      return S.getASTContext().IntTy;
+    return QualType();
+  // Logical operators, assume we want bool.
+  case tok::ampamp:
+  case tok::pipepipe:
+  case tok::caretcaret:
+    return S.getASTContext().BoolTy;
+  // Operators often used for bit manipulation are typically used with the type
+  // of the left argument.
+  case tok::pipe:
+  case tok::pipeequal:
+  case tok::caret:
+  case tok::caretequal:
+  case tok::amp:
+  case tok::ampequal:
+    if (LHSType->isIntegralOrEnumerationType())
+      return LHSType;
+    return QualType();
+  // RHS should be a pointer to a member of the 'LHS' type, but we can't give
+  // any particular type here.
+  case tok::periodstar:
+  case tok::arrowstar:
+    return QualType();
+  default:
+    // FIXME(ibiryukov): handle the missing op, re-add the assertion.
+    // assert(false && "unhandled binary op");
+    return QualType();
+  }
+}
+
+/// Get preferred type for an argument of an unary expression. \p ContextType is
+/// preferred type of the whole unary expression.
+static QualType getPreferredTypeOfUnaryArg(Sema &S, QualType ContextType,
+                                           tok::TokenKind Op) {
+  switch (Op) {
+  case tok::exclaim:
+    return S.getASTContext().BoolTy;
+  case tok::amp:
+    if (!ContextType.isNull() && ContextType->isPointerType())
+      return ContextType->getPointeeType();
+    return QualType();
+  case tok::star:
+    if (ContextType.isNull())
+      return QualType();
+    return S.getASTContext().getPointerType(ContextType.getNonReferenceType());
+  case tok::plus:
+  case tok::minus:
+  case tok::tilde:
+  case tok::minusminus:
+  case tok::plusplus:
+    if (ContextType.isNull())
+      return S.getASTContext().IntTy;
+    // leave as is, these operators typically return the same type.
+    return ContextType;
+  case tok::kw___real:
+  case tok::kw___imag:
+    return QualType();
+  default:
+    assert(false && "unhnalded unary op");
+    return QualType();
+  }
+}
+
+void PreferredTypeBuilder::enterBinary(Sema &S, SourceLocation Tok, Expr *LHS,
+                                       tok::TokenKind Op) {
+  Type = getPreferredTypeOfBinaryRHS(S, LHS, Op);
+  ExpectedLoc = Tok;
+}
+
+void PreferredTypeBuilder::enterMemAccess(Sema &S, SourceLocation Tok,
+                                          Expr *Base) {
+  if (!Base)
+    return;
+  Type = this->get(Base->getBeginLoc());
+  ExpectedLoc = Tok;
+}
+
+void PreferredTypeBuilder::enterUnary(Sema &S, SourceLocation Tok,
+                                      tok::TokenKind OpKind,
+                                      SourceLocation OpLoc) {
+  Type = getPreferredTypeOfUnaryArg(S, this->get(OpLoc), OpKind);
+  ExpectedLoc = Tok;
+}
+
+void PreferredTypeBuilder::enterSubscript(Sema &S, SourceLocation Tok,
+                                          Expr *LHS) {
+  Type = S.getASTContext().IntTy;
+  ExpectedLoc = Tok;
+}
+
+void PreferredTypeBuilder::enterTypeCast(SourceLocation Tok,
+                                         QualType CastType) {
+  Type = !CastType.isNull() ? CastType.getCanonicalType() : QualType();
+  ExpectedLoc = Tok;
+}
+
+void PreferredTypeBuilder::enterCondition(Sema &S, SourceLocation Tok) {
+  Type = S.getASTContext().BoolTy;
+  ExpectedLoc = Tok;
+}
+
 class ResultBuilder::ShadowMapEntry::iterator {
   llvm::PointerUnion<const NamedDecl *, const DeclIndexPair *> DeclOrIterator;
   unsigned SingleDeclIndex;
@@ -3856,13 +4032,15 @@ void Sema::CodeCompleteDeclSpec(Scope *S, DeclSpec &DS,
 }
 
 struct Sema::CodeCompleteExpressionData {
-  CodeCompleteExpressionData(QualType PreferredType = QualType())
+  CodeCompleteExpressionData(QualType PreferredType = QualType(),
+                             bool IsParenthesized = false)
       : PreferredType(PreferredType), IntegralConstantExpression(false),
-        ObjCCollection(false) {}
+        ObjCCollection(false), IsParenthesized(IsParenthesized) {}
 
   QualType PreferredType;
   bool IntegralConstantExpression;
   bool ObjCCollection;
+  bool IsParenthesized;
   SmallVector<Decl *, 4> IgnoreDecls;
 };
 
@@ -3873,13 +4051,18 @@ void Sema::CodeCompleteExpression(Scope *S,
   ResultBuilder Results(
       *this, CodeCompleter->getAllocator(),
       CodeCompleter->getCodeCompletionTUInfo(),
-      CodeCompletionContext(CodeCompletionContext::CCC_Expression,
-                            Data.PreferredType));
+      CodeCompletionContext(
+          Data.IsParenthesized
+              ? CodeCompletionContext::CCC_ParenthesizedExpression
+              : CodeCompletionContext::CCC_Expression,
+          Data.PreferredType));
+  auto PCC =
+      Data.IsParenthesized ? PCC_ParenthesizedExpression : PCC_Expression;
   if (Data.ObjCCollection)
     Results.setFilter(&ResultBuilder::IsObjCCollection);
   else if (Data.IntegralConstantExpression)
     Results.setFilter(&ResultBuilder::IsIntegralConstantValue);
-  else if (WantTypesInContext(PCC_Expression, getLangOpts()))
+  else if (WantTypesInContext(PCC, getLangOpts()))
     Results.setFilter(&ResultBuilder::IsOrdinaryName);
   else
     Results.setFilter(&ResultBuilder::IsOrdinaryNonTypeName);
@@ -3897,7 +4080,7 @@ void Sema::CodeCompleteExpression(Scope *S,
                      CodeCompleter->loadExternal());
 
   Results.EnterNewScope();
-  AddOrdinaryNameResults(PCC_Expression, S, *this, Results);
+  AddOrdinaryNameResults(PCC, S, *this, Results);
   Results.ExitScope();
 
   bool PreferredTypeIsPointer = false;
@@ -3917,13 +4100,16 @@ void Sema::CodeCompleteExpression(Scope *S,
                             Results.data(), Results.size());
 }
 
-void Sema::CodeCompleteExpression(Scope *S, QualType PreferredType) {
-  return CodeCompleteExpression(S, CodeCompleteExpressionData(PreferredType));
+void Sema::CodeCompleteExpression(Scope *S, QualType PreferredType,
+                                  bool IsParenthesized) {
+  return CodeCompleteExpression(
+      S, CodeCompleteExpressionData(PreferredType, IsParenthesized));
 }
 
-void Sema::CodeCompletePostfixExpression(Scope *S, ExprResult E) {
+void Sema::CodeCompletePostfixExpression(Scope *S, ExprResult E,
+                                         QualType PreferredType) {
   if (E.isInvalid())
-    CodeCompleteOrdinaryName(S, PCC_RecoveryInFunction);
+    CodeCompleteExpression(S, PreferredType);
   else if (getLangOpts().ObjC)
     CodeCompleteObjCInstanceMessage(S, E.get(), None, false);
 }
@@ -4211,7 +4397,8 @@ AddRecordMembersCompletionResults(Sema &SemaRef, ResultBuilder &Results,
 void Sema::CodeCompleteMemberReferenceExpr(Scope *S, Expr *Base,
                                            Expr *OtherOpBase,
                                            SourceLocation OpLoc, bool IsArrow,
-                                           bool IsBaseExprStatement) {
+                                           bool IsBaseExprStatement,
+                                           QualType PreferredType) {
   if (!Base || !CodeCompleter)
     return;
 
@@ -4239,6 +4426,7 @@ void Sema::CodeCompleteMemberReferenceExpr(Scope *S, Expr *Base,
   }
 
   CodeCompletionContext CCContext(contextKind, ConvertedBaseType);
+  CCContext.setPreferredType(PreferredType);
   ResultBuilder Results(*this, CodeCompleter->getAllocator(),
                         CodeCompleter->getCodeCompletionTUInfo(), CCContext,
                         &ResultBuilder::IsMember);
@@ -4800,22 +4988,6 @@ void Sema::CodeCompleteInitializer(Scope *S, Decl *D) {
   CodeCompleteExpression(S, Data);
 }
 
-void Sema::CodeCompleteReturn(Scope *S) {
-  QualType ResultType;
-  if (isa<BlockDecl>(CurContext)) {
-    if (BlockScopeInfo *BSI = getCurBlock())
-      ResultType = BSI->ReturnType;
-  } else if (const auto *Function = dyn_cast<FunctionDecl>(CurContext))
-    ResultType = Function->getReturnType();
-  else if (const auto *Method = dyn_cast<ObjCMethodDecl>(CurContext))
-    ResultType = Method->getReturnType();
-
-  if (ResultType.isNull())
-    CodeCompleteOrdinaryName(S, PCC_Expression);
-  else
-    CodeCompleteExpression(S, ResultType);
-}
-
 void Sema::CodeCompleteAfterIf(Scope *S) {
   ResultBuilder Results(*this, CodeCompleter->getAllocator(),
                         CodeCompleter->getCodeCompletionTUInfo(),
@@ -4877,91 +5049,6 @@ void Sema::CodeCompleteAfterIf(Scope *S) {
                             Results.data(), Results.size());
 }
 
-static QualType getPreferredTypeOfBinaryRHS(Sema &S, Expr *LHS,
-                                            tok::TokenKind Op) {
-  if (!LHS)
-    return QualType();
-
-  QualType LHSType = LHS->getType();
-  if (LHSType->isPointerType()) {
-    if (Op == tok::plus || Op == tok::plusequal || Op == tok::minusequal)
-      return S.getASTContext().getPointerDiffType();
-    // Pointer difference is more common than subtracting an int from a pointer.
-    if (Op == tok::minus)
-      return LHSType;
-  }
-
-  switch (Op) {
-  // No way to infer the type of RHS from LHS.
-  case tok::comma:
-    return QualType();
-  // Prefer the type of the left operand for all of these.
-  // Arithmetic operations.
-  case tok::plus:
-  case tok::plusequal:
-  case tok::minus:
-  case tok::minusequal:
-  case tok::percent:
-  case tok::percentequal:
-  case tok::slash:
-  case tok::slashequal:
-  case tok::star:
-  case tok::starequal:
-  // Assignment.
-  case tok::equal:
-  // Comparison operators.
-  case tok::equalequal:
-  case tok::exclaimequal:
-  case tok::less:
-  case tok::lessequal:
-  case tok::greater:
-  case tok::greaterequal:
-  case tok::spaceship:
-    return LHS->getType();
-  // Binary shifts are often overloaded, so don't try to guess those.
-  case tok::greatergreater:
-  case tok::greatergreaterequal:
-  case tok::lessless:
-  case tok::lesslessequal:
-    if (LHSType->isIntegralOrEnumerationType())
-      return S.getASTContext().IntTy;
-    return QualType();
-  // Logical operators, assume we want bool.
-  case tok::ampamp:
-  case tok::pipepipe:
-  case tok::caretcaret:
-    return S.getASTContext().BoolTy;
-  // Operators often used for bit manipulation are typically used with the type
-  // of the left argument.
-  case tok::pipe:
-  case tok::pipeequal:
-  case tok::caret:
-  case tok::caretequal:
-  case tok::amp:
-  case tok::ampequal:
-    if (LHSType->isIntegralOrEnumerationType())
-      return LHSType;
-    return QualType();
-  // RHS should be a pointer to a member of the 'LHS' type, but we can't give
-  // any particular type here.
-  case tok::periodstar:
-  case tok::arrowstar:
-    return QualType();
-  default:
-    // FIXME(ibiryukov): handle the missing op, re-add the assertion.
-    // assert(false && "unhandled binary op");
-    return QualType();
-  }
-}
-
-void Sema::CodeCompleteBinaryRHS(Scope *S, Expr *LHS, tok::TokenKind Op) {
-  auto PreferredType = getPreferredTypeOfBinaryRHS(*this, LHS, Op);
-  if (!PreferredType.isNull())
-    CodeCompleteExpression(S, PreferredType);
-  else
-    CodeCompleteOrdinaryName(S, PCC_Expression);
-}
-
 void Sema::CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS,
                                    bool EnteringContext, QualType BaseType) {
   if (SS.isEmpty() || !CodeCompleter)
diff --git a/unittests/Sema/CodeCompleteTest.cpp b/unittests/Sema/CodeCompleteTest.cpp
index d44e0ece55..3bec79dc9a 100644
--- a/unittests/Sema/CodeCompleteTest.cpp
+++ b/unittests/Sema/CodeCompleteTest.cpp
@@ -339,4 +339,103 @@ TEST(PreferredTypeTest, BinaryExpr) {
   EXPECT_THAT(collectPreferredTypes(Code), Each("NULL TYPE"));
 }
 
+TEST(PreferredTypeTest, Members) {
+  StringRef Code = R"cpp(
+    struct vector {
+      int *begin();
+      vector clone();
+    };
+
+    void test(int *a) {
+      a = ^vector().^clone().^begin();
+    }
+  )cpp";
+  EXPECT_THAT(collectPreferredTypes(Code), Each("int *"));
+}
+
+TEST(PreferredTypeTest, Conditions) {
+  StringRef Code = R"cpp(
+    struct vector {
+      bool empty();
+    };
+
+    void test() {
+      if (^vector().^empty()) {}
+      while (^vector().^empty()) {}
+      for (; ^vector().^empty();) {}
+    }
+  )cpp";
+  EXPECT_THAT(collectPreferredTypes(Code), Each("_Bool"));
+}
+
+TEST(PreferredTypeTest, InitAndAssignment) {
+  StringRef Code = R"cpp(
+    struct vector {
+      int* begin();
+    };
+
+    void test() {
+      const int* x = ^vector().^begin();
+      x = ^vector().^begin();
+
+      if (const int* y = ^vector().^begin()) {}
+    }
+  )cpp";
+  EXPECT_THAT(collectPreferredTypes(Code), Each("const int *"));
+}
+
+TEST(PreferredTypeTest, UnaryExprs) {
+  StringRef Code = R"cpp(
+    void test(long long a) {
+      a = +^a;
+      a = -^a
+      a = ++^a;
+      a = --^a;
+    }
+  )cpp";
+  EXPECT_THAT(collectPreferredTypes(Code), Each("long long"));
+
+  Code = R"cpp(
+    void test(int a, int *ptr) {
+      !^a;
+      !^ptr;
+      !!!^a;
+
+      a = !^a;
+      a = !^ptr;
+      a = !!!^a;
+    }
+  )cpp";
+  EXPECT_THAT(collectPreferredTypes(Code), Each("_Bool"));
+
+  Code = R"cpp(
+    void test(int a) {
+      const int* x = &^a;
+    }
+  )cpp";
+  EXPECT_THAT(collectPreferredTypes(Code), Each("const int"));
+
+  Code = R"cpp(
+    void test(int *a) {
+      int x = *^a;
+      int &r = *^a;
+    }
+  )cpp";
+  EXPECT_THAT(collectPreferredTypes(Code), Each("int *"));
+
+  Code = R"cpp(
+    void test(int a) {
+      *^a;
+      &^a;
+    }
+
+  )cpp";
+}
+
+TEST(PreferredTypeTest, ParenExpr) {
+  StringRef Code = R"cpp(
+    const int *i = ^(^(^(^10)));
+  )cpp";
+  EXPECT_THAT(collectPreferredTypes(Code), Each("const int *"));
+}
 } // namespace