r336810 - [clangd] Uprank delcarations when "using q::name" is present in the main file

[Kirill Bobyrev via cfe-commits]

Author: omtcyfz
Date: Wed Jul 11 07:49:49 2018
New Revision: 336810

URL: http://llvm.org/viewvc/llvm-project?rev=336810&view=rev
Log:
[clangd] Uprank delcarations when "using q::name" is present in the main file

Having `using qualified::name;` for some symbol is an important signal
for clangd code completion as the user is more likely to use such
symbol.  This patch helps to uprank the relevant symbols by saving
UsingShadowDecl in the new field of CodeCompletionResult and checking
whether the corresponding UsingShadowDecl is located in the main file
later in ClangD code completion routine. While the relative importance
of such signal is a subject to change in the future, this patch simply
bumps DeclProximity score to the value of 1.0 which should be enough for
now.

The patch was tested using

`$ ninja check-clang check-clang-tools`

No unexpected failures were noticed after running the relevant testsets.

Reviewers: sammccall, ioeric

Subscribers: MaskRay, jkorous, cfe-commits

Differential Revision: https://reviews.llvm.org/D49012

Modified:
    cfe/trunk/include/clang/Sema/CodeCompleteConsumer.h
    cfe/trunk/lib/Sema/SemaCodeComplete.cpp

Modified: cfe/trunk/include/clang/Sema/CodeCompleteConsumer.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/CodeCompleteConsumer.h?rev=336810&r1=336809&r2=336810&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/CodeCompleteConsumer.h (original)
+++ cfe/trunk/include/clang/Sema/CodeCompleteConsumer.h Wed Jul 11 07:49:49 2018
@@ -45,8 +45,9 @@ class LangOptions;
 class NamedDecl;
 class NestedNameSpecifier;
 class Preprocessor;
-class Sema;
 class RawComment;
+class Sema;
+class UsingShadowDecl;
 
 /// Default priority values for code-completion results based
 /// on their kind.
@@ -836,6 +837,12 @@ public:
   /// informative rather than required.
   NestedNameSpecifier *Qualifier = nullptr;
 
+  /// If this Decl was unshadowed by using declaration, this can store a
+  /// pointer to the UsingShadowDecl which was used in the unshadowing process.
+  /// This information can be used to uprank CodeCompletionResults / which have
+  /// corresponding `using decl::qualified::name;` nearby.
+  const UsingShadowDecl *ShadowDecl = nullptr;
+
   /// Build a result that refers to a declaration.
   CodeCompletionResult(const NamedDecl *Declaration, unsigned Priority,
                        NestedNameSpecifier *Qualifier = nullptr,
@@ -847,7 +854,7 @@ public:
         QualifierIsInformative(QualifierIsInformative),
         StartsNestedNameSpecifier(false), AllParametersAreInformative(false),
         DeclaringEntity(false), Qualifier(Qualifier) {
-    //FIXME: Add assert to check FixIts range requirements.
+    // FIXME: Add assert to check FixIts range requirements.
     computeCursorKindAndAvailability(Accessible);
   }
 

Modified: cfe/trunk/lib/Sema/SemaCodeComplete.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaCodeComplete.cpp?rev=336810&r1=336809&r2=336810&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaCodeComplete.cpp (original)
+++ cfe/trunk/lib/Sema/SemaCodeComplete.cpp Wed Jul 11 07:49:49 2018
@@ -859,12 +859,12 @@ void ResultBuilder::MaybeAddResult(Resul
   }
 
   // Look through using declarations.
-  if (const UsingShadowDecl *Using =
-          dyn_cast<UsingShadowDecl>(R.Declaration)) {
-    MaybeAddResult(Result(Using->getTargetDecl(),
-                          getBasePriority(Using->getTargetDecl()),
-                          R.Qualifier),
-                   CurContext);
+  if (const UsingShadowDecl *Using = dyn_cast<UsingShadowDecl>(R.Declaration)) {
+    CodeCompletionResult Result(Using->getTargetDecl(),
+                                getBasePriority(Using->getTargetDecl()),
+                                R.Qualifier);
+    Result.ShadowDecl = Using;
+    MaybeAddResult(Result, CurContext);
     return;
   }
 
@@ -977,10 +977,11 @@ void ResultBuilder::AddResult(Result R,
 
   // Look through using declarations.
   if (const UsingShadowDecl *Using = dyn_cast<UsingShadowDecl>(R.Declaration)) {
-    AddResult(Result(Using->getTargetDecl(),
-                     getBasePriority(Using->getTargetDecl()),
-                     R.Qualifier),
-              CurContext, Hiding);
+    CodeCompletionResult Result(Using->getTargetDecl(),
+                                getBasePriority(Using->getTargetDecl()),
+                                R.Qualifier);
+    Result.ShadowDecl = Using;
+    AddResult(Result, CurContext, Hiding);
     return;
   }
 
@@ -1004,10 +1005,10 @@ void ResultBuilder::AddResult(Result R,
   if (AsNestedNameSpecifier) {
     R.StartsNestedNameSpecifier = true;
     R.Priority = CCP_NestedNameSpecifier;
-  }
-  else if (Filter == &ResultBuilder::IsMember && !R.Qualifier && InBaseClass &&
-           isa<CXXRecordDecl>(R.Declaration->getDeclContext()
-                                                  ->getRedeclContext()))
+  } else if (Filter == &ResultBuilder::IsMember && !R.Qualifier &&
+             InBaseClass &&
+             isa<CXXRecordDecl>(
+                 R.Declaration->getDeclContext()->getRedeclContext()))
     R.QualifierIsInformative = true;
 
   // If this result is supposed to have an informative qualifier, add one.