[CodeComplete] Filter override completions by function name

Summary:
We put only part of the signature starting with a function name into "typed text"
chunks now, previously the whole signature was "typed text".

This leads to meaningful fuzzy match scores, giving better signals to
compare with other completion items.

Ideally, we would not display the result type to the user, but that requires adding
a new kind of completion chunk.

Reviewers: kadircet

Reviewed By: kadircet

Subscribers: jkorous, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D62298

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@361623 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/SemaCodeComplete.cpp

@@ -37,6 +37,7 @@
 #include "llvm/Support/Path.h"
 #include <list>
 #include <map>
+#include <string>
 #include <vector>
 
 using namespace clang;
@@ -1828,19 +1829,6 @@ static void AddStaticAssertResult(CodeCompletionBuilder &Builder,
   Results.AddResult(CodeCompletionResult(Builder.TakeString()));
 }
 
-static void printOverrideString(llvm::raw_ostream &OS,
-                                CodeCompletionString *CCS) {
-  for (const auto &C : *CCS) {
-    if (C.Kind == CodeCompletionString::CK_Optional)
-      printOverrideString(OS, C.Optional);
-    else
-      OS << C.Text;
-    // Add a space after return type.
-    if (C.Kind == CodeCompletionString::CK_ResultType)
-      OS << ' ';
-  }
-}
-
 static void AddOverrideResults(ResultBuilder &Results,
                                const CodeCompletionContext &CCContext,
                                CodeCompletionBuilder &Builder) {
@@ -3162,19 +3150,42 @@ CodeCompletionString *CodeCompletionResult::CreateCodeCompletionString(
       PP, Ctx, Result, IncludeBriefComments, CCContext, Policy);
 }
 
+static void printOverrideString(const CodeCompletionString &CCS,
+                                std::string &BeforeName,
+                                std::string &NameAndSignature) {
+  bool SeenTypedChunk = false;
+  for (auto &Chunk : CCS) {
+    if (Chunk.Kind == CodeCompletionString::CK_Optional) {
+      assert(SeenTypedChunk && "optional parameter before name");
+      // Note that we put all chunks inside into NameAndSignature.
+      printOverrideString(*Chunk.Optional, NameAndSignature, NameAndSignature);
+      continue;
+    }
+    SeenTypedChunk |= Chunk.Kind == CodeCompletionString::CK_TypedText;
+    if (SeenTypedChunk)
+      NameAndSignature += Chunk.Text;
+    else
+      BeforeName += Chunk.Text;
+  }
+}
+
 CodeCompletionString *
 CodeCompletionResult::createCodeCompletionStringForOverride(
     Preprocessor &PP, ASTContext &Ctx, CodeCompletionBuilder &Result,
     bool IncludeBriefComments, const CodeCompletionContext &CCContext,
     PrintingPolicy &Policy) {
-  std::string OverrideSignature;
-  llvm::raw_string_ostream OS(OverrideSignature);
   auto *CCS = createCodeCompletionStringForDecl(PP, Ctx, Result,
                                                 /*IncludeBriefComments=*/false,
                                                 CCContext, Policy);
-  printOverrideString(OS, CCS);
-  OS << " override";
-  Result.AddTypedTextChunk(Result.getAllocator().CopyString(OS.str()));
+  std::string BeforeName;
+  std::string NameAndSignature;
+  // For overrides all chunks go into the result, none are informative.
+  printOverrideString(*CCS, BeforeName, NameAndSignature);
+  NameAndSignature += " override";
+
+  Result.AddTextChunk(Result.getAllocator().CopyString(BeforeName));
+  Result.AddChunk(CodeCompletionString::CK_HorizontalSpace);
+  Result.AddTypedTextChunk(Result.getAllocator().CopyString(NameAndSignature));
   return Result.TakeString();
 }
 

test/CodeCompletion/overrides.cpp

@@ -11,23 +11,23 @@ void vfunc(bool param, int p) override;
 class C : public B {
  public:
   void vfunc(bool param) override;
-  void
+  vf
 };
 
-// Runs completion at ^void.
+// Runs completion at ^vf
 // RUN: %clang_cc1 -fsyntax-only -code-completion-at=%s:14:3 %s -o - | FileCheck -check-prefix=CHECK-CC1 %s
 // CHECK-CC1: COMPLETION: Pattern : int ttt(bool param, int x = 3) const override{{$}}
 // CHECK-CC1: COMPLETION: Pattern : void vfunc(bool param, int p) override{{$}}
 // CHECK-CC1-NOT: COMPLETION: Pattern : void vfunc(bool param) override{{$}}
 //
-// Runs completion at vo^id.
+// Runs completion at vf^
 // RUN: %clang_cc1 -fsyntax-only -code-completion-at=%s:14:5 %s -o - | FileCheck -check-prefix=CHECK-CC2 %s
-// CHECK-CC2: COMPLETION: Pattern : void vfunc(bool param, int p) override{{$}}
 // CHECK-CC2-NOT: COMPLETION: Pattern : int ttt(bool param, int x = 3) const override{{$}}
+// CHECK-CC2: COMPLETION: Pattern : void vfunc(bool param, int p) override{{$}}
 // CHECK-CC2-NOT: COMPLETION: Pattern : void vfunc(bool param) override{{$}}
 //
-// Runs completion at void ^.
-// RUN: %clang_cc1 -fsyntax-only -code-completion-at=%s:14:8 %s -o - | FileCheck -check-prefix=CHECK-CC3 %s
+// Runs completion at void ^ on line 13.
+// RUN: %clang_cc1 -fsyntax-only -code-completion-at=%s:13:8 %s -o - | FileCheck -check-prefix=CHECK-CC3 %s
 // CHECK-CC3-NOT: COMPLETION: Pattern : int ttt(bool param, int x = 3) const override{{$}}
 // CHECK-CC3-NOT: COMPLETION: Pattern : void vfunc(bool param, int p) override{{$}}
 // CHECK-CC3-NOT: COMPLETION: Pattern : void vfunc(bool param) override{{$}}