[clang] Apply FixIts to members declared via `using` in derived classes

[denis-fatkulin]

Summary

FixIt don't switch to arrow in derrived members with using

Example code:

struct Bar {
  void foo();
};
struct Baz {
  using Bar::foo;
};
void test(Baz* ptr) {
  ptr.^
}

[kadircet]

thanks lgtm!

clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp

2187

no need for this test in clangd, as it's testing the same thing you've in clang lit test (and clang is the righteous place to test this behavior)

clang/lib/Sema/SemaCodeComplete.cpp

1101

can you also fix the constructor call here?

1276

you can just pass std::move(R.FixIts) as the next argument in this constructor call instead.

[denis-fatkulin]

Patch is updatetd according to remarks by @kadircet.

@kadircet, could you please also merge my pacth to code base? I haven't such permissions yet.
My git user name and address: Denis Fatkulin ([e-mail])

Thank you for the review!

[denis-fatkulin]

clang/lib/Sema/SemaCodeComplete.cpp

1276

Fixed.

[kadircet]

looks like you've uploaded the diff without context, can you upload it again with full context? also the changes to MaybeAddResult seem to be missing.

[denis-fatkulin]

Patch is updated with context

clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp

 //===-- CodeCompleteTests.cpp -----------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
TEST(CompletionTest, RenderWithFixItMerged) {
   Opts.IncludeFixIts = true;
 
   auto R = C.render(Opts);
   EXPECT_TRUE(R.textEdit);
   EXPECT_EQ(R.textEdit->newText, "->Foo::x");
   EXPECT_TRUE(R.additionalTextEdits.empty());
 }
 
+TEST(CompletionTest, FixItForMembersUsing) {
+  const Annotations Code(R"cpp(
+    struct Bar {
+        void method();
+        int field;
+      };
+      struct Baz : Bar {
+        using Bar::method;
+        using Bar::field;
+      };
+      void foo(Baz* ptr) {
+        ptr.m^ethod();
+        ptr.f^ield;
+      }
+  )cpp");
+
+  TestTU TU;
+  TU.Code = Code.code().str();
+  auto CheckCompletion = [&TU](const Position &Pos, const std::string &Name) {
+    clangd::CodeCompleteOptions Opts;
+    Opts.IncludeFixIts = true;
+
+    const auto Completions = completions(TU, Pos, {}, Opts).Completions;
+    ASSERT_EQ(Completions.size(), 1u);
+    EXPECT_EQ(Completions[0].Name, Name);
+
+    const auto R = Completions[0].render(Opts);
+    ASSERT_TRUE(R.textEdit);
+    EXPECT_EQ(R.textEdit->newText, "->" + Name);
+  };
+
+  const auto Points = Code.points();
+  CheckCompletion(Points[0], "method");
+  CheckCompletion(Points[1], "field");
+}
+
 TEST(CompletionTest, RenderWithFixItNonMerged) {
   TextEdit FixIt;
   FixIt.range.end.character = 4;
   FixIt.newText = "->";
 
   CodeCompletion C;
   C.Name = "x";
   C.RequiredQualifier = "Foo::";

clang/lib/Sema/SemaCodeComplete.cpp

 //===---------------- SemaCodeComplete.cpp - Code Completion ----*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
void ResultBuilder::MaybeAddResult(Result R, DeclContext *CurContext) {
   }
 
   // Look through using declarations.
   if (const UsingShadowDecl *Using = dyn_cast<UsingShadowDecl>(R.Declaration)) {
     CodeCompletionResult Result(Using->getTargetDecl(),
                                 getBasePriority(Using->getTargetDecl()),
                                 R.Qualifier, false,
                                 (R.Availability == CXAvailability_Available ||
                                  R.Availability == CXAvailability_Deprecated));
     Result.ShadowDecl = Using;
     MaybeAddResult(Result, CurContext);
     return;
   }
 
   const Decl *CanonDecl = R.Declaration->getCanonicalDecl();
   unsigned IDNS = CanonDecl->getIdentifierNamespace();
 
void ResultBuilder::AddResult(Result R, DeclContext *CurContext,
   }
 
   // Look through using declarations.
   if (const auto *Using = dyn_cast<UsingShadowDecl>(R.Declaration)) {
     CodeCompletionResult Result(Using->getTargetDecl(),
                                 getBasePriority(Using->getTargetDecl()),
                                 R.Qualifier, false,
                                 (R.Availability == CXAvailability_Available ||
                                  R.Availability == CXAvailability_Deprecated));
     Result.ShadowDecl = Using;
+    Result.FixIts = R.FixIts;
     AddResult(Result, CurContext, Hiding);
     return;
   }
 
   bool AsNestedNameSpecifier = false;
   if (!isInterestingDecl(R.Declaration, AsNestedNameSpecifier))
     return;
 

clang/test/CodeCompletion/member-access.cpp

 
 template <typename T>
 void testMembersFromBasesInDependentContext() {
   Derived2<T> X;
   (void)X.base4().base4();
   // RUN: %clang_cc1 -fsyntax-only -code-completion-at=%s:310:19 %s -o - | FileCheck -check-prefix=CHECK-MEMBERS-FROM-BASE-DEPENDENT %s
   // CHECK-MEMBERS-FROM-BASE-DEPENDENT: [#Base4#]base4
 }
+
+namespace members_using_fixits {
+  struct Bar {
+    void method();
+    int field;
+  };
+  struct Baz: Bar {
+    using Bar::method;
+    using Bar::field;
+  };
+  void testMethod(Baz* ptr) {
+    ptr.m
+  }
+  // RUN: %clang_cc1 -fsyntax-only -code-completion-with-fixits -code-completion-at=%s:325:10 %s -o - | FileCheck -check-prefix=CHECK-METHOD-DECLARED-VIA-USING %s
+  // CHECK-METHOD-DECLARED-VIA-USING: [#void#]method() (requires fix-it: {325:8-325:9} to "->")
+
+  void testField(Baz* ptr) {
+    ptr.f
+  }
+  // RUN: %clang_cc1 -fsyntax-only -code-completion-with-fixits -code-completion-at=%s:331:10 %s -o - | FileCheck -check-prefix=CHECK-FIELD-DECLARED-VIA-USING %s
+  // CHECK-FIELD-DECLARED-VIA-USING: [#int#]field (requires fix-it: {331:8-331:9} to "->")
+}