Optionally add code completion results for arrow instead of dot

Currently getting such completions requires source correction, reparsing
and calling completion again. And if it shows no results and rollback is
required then it costs one more reparse.

With this change it's possible to get all results which can be later
filtered to split changes which require correction.

Differential Revision: https://reviews.llvm.org/D41537

llvm-svn: 333272

1 files changed, 120 insertions, 82 deletions

diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index f08159b7..5bc428a 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -1291,10 +1291,13 @@ namespace {
   class CodeCompletionDeclConsumer : public VisibleDeclConsumer {
     ResultBuilder &Results;
     DeclContext *CurContext;
+    std::vector<FixItHint> FixIts;
 
   public:
-    CodeCompletionDeclConsumer(ResultBuilder &Results, DeclContext *CurContext)
-      : Results(Results), CurContext(CurContext) { }
+    CodeCompletionDeclConsumer(
+        ResultBuilder &Results, DeclContext *CurContext,
+        std::vector<FixItHint> FixIts = std::vector<FixItHint>())
+        : Results(Results), CurContext(CurContext), FixIts(std::move(FixIts)) {}
 
     void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, DeclContext *Ctx,
                    bool InBaseClass) override {
@@ -1303,7 +1306,7 @@ namespace {
         Accessible = Results.getSema().IsSimplyAccessible(ND, Ctx);
 
       ResultBuilder::Result Result(ND, Results.getBasePriority(ND), nullptr,
-                                   false, Accessible);
+                                   false, Accessible, FixIts);
       Results.AddResult(Result, CurContext, Hiding, InBaseClass);
     }
 
@@ -3979,14 +3982,18 @@ static void AddObjCProperties(
 static void AddRecordMembersCompletionResults(Sema &SemaRef,
                                               ResultBuilder &Results, Scope *S,
                                               QualType BaseType,
-                                              RecordDecl *RD) {
+                                              RecordDecl *RD,
+                                              Optional<FixItHint> AccessOpFixIt) {
   // Indicate that we are performing a member access, and the cv-qualifiers
   // for the base object type.
   Results.setObjectTypeQualifiers(BaseType.getQualifiers());
 
   // Access to a C/C++ class, struct, or union.
   Results.allowNestedNameSpecifiers();
-  CodeCompletionDeclConsumer Consumer(Results, SemaRef.CurContext);
+  std::vector<FixItHint> FixIts;
+  if (AccessOpFixIt)
+      FixIts.emplace_back(AccessOpFixIt.getValue());
+  CodeCompletionDeclConsumer Consumer(Results, SemaRef.CurContext, std::move(FixIts));
   SemaRef.LookupVisibleDecls(RD, Sema::LookupMemberName, Consumer,
                              SemaRef.CodeCompleter->includeGlobals(),
                              /*IncludeDependentBases=*/true,
@@ -4013,107 +4020,138 @@ static void AddRecordMembersCompletionResults(Sema &SemaRef,
 }
 
 void Sema::CodeCompleteMemberReferenceExpr(Scope *S, Expr *Base,
+                                           Expr *OtherOpBase,
                                            SourceLocation OpLoc, bool IsArrow,
                                            bool IsBaseExprStatement) {
   if (!Base || !CodeCompleter)
     return;
-  
+
   ExprResult ConvertedBase = PerformMemberExprBaseConversion(Base, IsArrow);
   if (ConvertedBase.isInvalid())
     return;
-  Base = ConvertedBase.get();
-  
-  QualType BaseType = Base->getType();
+  QualType ConvertedBaseType = ConvertedBase.get()->getType();
+
+  enum CodeCompletionContext::Kind contextKind;
 
   if (IsArrow) {
-    if (const PointerType *Ptr = BaseType->getAs<PointerType>())
-      BaseType = Ptr->getPointeeType();
-    else if (BaseType->isObjCObjectPointerType())
-      /*Do nothing*/ ;
-    else
-      return;
+    if (const PointerType *Ptr = ConvertedBaseType->getAs<PointerType>())
+      ConvertedBaseType = Ptr->getPointeeType();
   }
-  
-  enum CodeCompletionContext::Kind contextKind;
-  
+
   if (IsArrow) {
     contextKind = CodeCompletionContext::CCC_ArrowMemberAccess;
-  }
-  else {
-    if (BaseType->isObjCObjectPointerType() ||
-        BaseType->isObjCObjectOrInterfaceType()) {
+  } else {
+    if (ConvertedBaseType->isObjCObjectPointerType() ||
+        ConvertedBaseType->isObjCObjectOrInterfaceType()) {
       contextKind = CodeCompletionContext::CCC_ObjCPropertyAccess;
-    }
-    else {
+    } else {
       contextKind = CodeCompletionContext::CCC_DotMemberAccess;
     }
   }
 
-  CodeCompletionContext CCContext(contextKind, BaseType);
+  CodeCompletionContext CCContext(contextKind, ConvertedBaseType);
   ResultBuilder Results(*this, CodeCompleter->getAllocator(),
-                        CodeCompleter->getCodeCompletionTUInfo(),
-                        CCContext,
+                        CodeCompleter->getCodeCompletionTUInfo(), CCContext,
                         &ResultBuilder::IsMember);
-  Results.EnterNewScope();
-  if (const RecordType *Record = BaseType->getAs<RecordType>()) {
-    AddRecordMembersCompletionResults(*this, Results, S, BaseType,
-                                      Record->getDecl());
-  } else if (const auto *TST = BaseType->getAs<TemplateSpecializationType>()) {
-    TemplateName TN = TST->getTemplateName();
-    if (const auto *TD =
-            dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl())) {
-      CXXRecordDecl *RD = TD->getTemplatedDecl();
-      AddRecordMembersCompletionResults(*this, Results, S, BaseType, RD);
-    }
-  } else if (const auto *ICNT = BaseType->getAs<InjectedClassNameType>()) {
-    if (auto *RD = ICNT->getDecl())
-      AddRecordMembersCompletionResults(*this, Results, S, BaseType, RD);
-  } else if (!IsArrow && BaseType->isObjCObjectPointerType()) {
-    // Objective-C property reference.
-    AddedPropertiesSet AddedProperties;
-
-    if (const ObjCObjectPointerType *ObjCPtr =
-            BaseType->getAsObjCInterfacePointerType()) {
-      // Add property results based on our interface.
-      assert(ObjCPtr && "Non-NULL pointer guaranteed above!");
-      AddObjCProperties(CCContext, ObjCPtr->getInterfaceDecl(), true,
-                        /*AllowNullaryMethods=*/true, CurContext,
-                        AddedProperties, Results, IsBaseExprStatement);
-    }
-
-    // Add properties from the protocols in a qualified interface.
-    for (auto *I : BaseType->getAs<ObjCObjectPointerType>()->quals())
-      AddObjCProperties(CCContext, I, true, /*AllowNullaryMethods=*/true,
-                        CurContext, AddedProperties, Results,
-                        IsBaseExprStatement);
-  } else if ((IsArrow && BaseType->isObjCObjectPointerType()) ||
-             (!IsArrow && BaseType->isObjCObjectType())) {
-    // Objective-C instance variable access.
-    ObjCInterfaceDecl *Class = nullptr;
-    if (const ObjCObjectPointerType *ObjCPtr
-                                    = BaseType->getAs<ObjCObjectPointerType>())
-      Class = ObjCPtr->getInterfaceDecl();
-    else
-      Class = BaseType->getAs<ObjCObjectType>()->getInterface();
-    
-    // Add all ivars from this class and its superclasses.
-    if (Class) {
-      CodeCompletionDeclConsumer Consumer(Results, CurContext);
-      Results.setFilter(&ResultBuilder::IsObjCIvar);
-      LookupVisibleDecls(
-          Class, LookupMemberName, Consumer, CodeCompleter->includeGlobals(),
-          /*IncludeDependentBases=*/false, CodeCompleter->loadExternal());
+
+  auto DoCompletion = [&](Expr *Base, bool IsArrow, Optional<FixItHint> AccessOpFixIt) -> bool {
+    if (!Base)
+      return false;
+
+    ExprResult ConvertedBase = PerformMemberExprBaseConversion(Base, IsArrow);
+    if (ConvertedBase.isInvalid())
+      return false;
+    Base = ConvertedBase.get();
+
+    QualType BaseType = Base->getType();
+
+    if (IsArrow) {
+      if (const PointerType *Ptr = BaseType->getAs<PointerType>())
+        BaseType = Ptr->getPointeeType();
+      else if (BaseType->isObjCObjectPointerType())
+        /*Do nothing*/;
+      else
+        return false;
+    }
+
+    if (const RecordType *Record = BaseType->getAs<RecordType>()) {
+      AddRecordMembersCompletionResults(*this, Results, S, BaseType,
+                                        Record->getDecl(),
+                                        std::move(AccessOpFixIt));
+    } else if (const auto *TST =
+                   BaseType->getAs<TemplateSpecializationType>()) {
+      TemplateName TN = TST->getTemplateName();
+      if (const auto *TD =
+              dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl())) {
+        CXXRecordDecl *RD = TD->getTemplatedDecl();
+        AddRecordMembersCompletionResults(*this, Results, S, BaseType, RD,
+                                          std::move(AccessOpFixIt));
+      }
+    } else if (const auto *ICNT = BaseType->getAs<InjectedClassNameType>()) {
+      if (auto *RD = ICNT->getDecl())
+        AddRecordMembersCompletionResults(*this, Results, S, BaseType, RD,
+                                          std::move(AccessOpFixIt));
+    } else if (!IsArrow && BaseType->isObjCObjectPointerType()) {
+      // Objective-C property reference.
+      AddedPropertiesSet AddedProperties;
+
+      if (const ObjCObjectPointerType *ObjCPtr =
+              BaseType->getAsObjCInterfacePointerType()) {
+        // Add property results based on our interface.
+        assert(ObjCPtr && "Non-NULL pointer guaranteed above!");
+        AddObjCProperties(CCContext, ObjCPtr->getInterfaceDecl(), true,
+                          /*AllowNullaryMethods=*/true, CurContext,
+                          AddedProperties, Results, IsBaseExprStatement);
+      }
+
+      // Add properties from the protocols in a qualified interface.
+      for (auto *I : BaseType->getAs<ObjCObjectPointerType>()->quals())
+        AddObjCProperties(CCContext, I, true, /*AllowNullaryMethods=*/true,
+                          CurContext, AddedProperties, Results,
+                          IsBaseExprStatement);
+    } else if ((IsArrow && BaseType->isObjCObjectPointerType()) ||
+               (!IsArrow && BaseType->isObjCObjectType())) {
+      // Objective-C instance variable access.
+      ObjCInterfaceDecl *Class = nullptr;
+      if (const ObjCObjectPointerType *ObjCPtr =
+              BaseType->getAs<ObjCObjectPointerType>())
+        Class = ObjCPtr->getInterfaceDecl();
+      else
+        Class = BaseType->getAs<ObjCObjectType>()->getInterface();
+
+      // Add all ivars from this class and its superclasses.
+      if (Class) {
+        CodeCompletionDeclConsumer Consumer(Results, CurContext);
+        Results.setFilter(&ResultBuilder::IsObjCIvar);
+        LookupVisibleDecls(
+            Class, LookupMemberName, Consumer, CodeCompleter->includeGlobals(),
+            /*IncludeDependentBases=*/false, CodeCompleter->loadExternal());
+      }
     }
+
+    // FIXME: How do we cope with isa?
+    return true;
+  };
+
+  Results.EnterNewScope();
+
+  bool CompletionSucceded = DoCompletion(Base, IsArrow, None);
+  if (CodeCompleter->includeFixIts()) {
+    const CharSourceRange OpRange =
+        CharSourceRange::getTokenRange(OpLoc, OpLoc);
+    CompletionSucceded |= DoCompletion(
+        OtherOpBase, !IsArrow,
+        FixItHint::CreateReplacement(OpRange, IsArrow ? "." : "->"));
   }
-  
-  // FIXME: How do we cope with isa?
-  
+
   Results.ExitScope();
 
+  if (!CompletionSucceded)
+    return;
+
   // Hand off the results found for code completion.
-  HandleCodeCompleteResults(this, CodeCompleter, 
-                            Results.getCompletionContext(),
-                            Results.data(),Results.size());
+  HandleCodeCompleteResults(this, CodeCompleter, Results.getCompletionContext(),
+                            Results.data(), Results.size());
 }
 
 void Sema::CodeCompleteObjCClassPropertyRefExpr(Scope *S,