[clangd] Add type boosting in code completion

Reviewers: sammccall, ioeric

Reviewed By: sammccall

Subscribers: MaskRay, jkorous, arphaman, kadircet, cfe-commits

Differential Revision: https://reviews.llvm.org/D52276

llvm-svn: 347562

4 files changed, 43 insertions, 2 deletions

diff --git a/clang-tools-extra/clangd/CodeComplete.cpp b/clang-tools-extra/clangd/CodeComplete.cpp
index c79f0171761..28cc5837cef 100644
--- a/clang-tools-extra/clangd/CodeComplete.cpp
+++ b/clang-tools-extra/clangd/CodeComplete.cpp
@@ -24,6 +24,7 @@
 #include "CodeCompletionStrings.h"
 #include "Compiler.h"
 #include "Diagnostics.h"
+#include "ExpectedTypes.h"
 #include "FileDistance.h"
 #include "FuzzyMatch.h"
 #include "Headers.h"
@@ -1225,6 +1226,7 @@ class CodeCompleteFlow {
   std::vector<std::string> QueryScopes; // Initialized once Sema runs.
   // Initialized once QueryScopes is initialized, if there are scopes.
   Optional<ScopeDistance> ScopeProximity;
+  llvm::Optional<OpaqueType> PreferredType; // Initialized once Sema runs.
   // Whether to query symbols from any scope. Initialized once Sema runs.
   bool AllScopes = false;
   // Include-insertion and proximity scoring rely on the include structure.
@@ -1302,9 +1304,12 @@ public:
       Inserter.reset(); // Make sure this doesn't out-live Clang.
       SPAN_ATTACH(Tracer, "sema_completion_kind",
                   getCompletionKindString(Recorder->CCContext.getKind()));
-      log("Code complete: sema context {0}, query scopes [{1}] (AnyScope={2})",
+      log("Code complete: sema context {0}, query scopes [{1}] (AnyScope={2}), "
+          "expected type {3}",
           getCompletionKindString(Recorder->CCContext.getKind()),
-          join(QueryScopes.begin(), QueryScopes.end(), ","), AllScopes);
+          join(QueryScopes.begin(), QueryScopes.end(), ","), AllScopes,
+          PreferredType ? Recorder->CCContext.getPreferredType().getAsString()
+                        : "<none>");
     });
 
     Recorder = RecorderOwner.get();
@@ -1354,6 +1359,9 @@ private:
         getQueryScopes(Recorder->CCContext, *Recorder->CCSema, Opts);
     if (!QueryScopes.empty())
       ScopeProximity.emplace(QueryScopes);
+    PreferredType =
+        OpaqueType::fromType(Recorder->CCSema->getASTContext(),
+                             Recorder->CCContext.getPreferredType());
     // Sema provides the needed context to query the index.
     // FIXME: in addition to querying for extra/overlapping symbols, we should
     //        explicitly request symbols corresponding to Sema results.
@@ -1492,6 +1500,8 @@ private:
     Relevance.FileProximityMatch = FileProximity.getPointer();
     if (ScopeProximity)
       Relevance.ScopeProximityMatch = ScopeProximity.getPointer();
+    if (PreferredType)
+      Relevance.HadContextType = true;
 
     auto &First = Bundle.front();
     if (auto FuzzyScore = fuzzyScore(First))
@@ -1506,10 +1516,24 @@ private:
         Relevance.merge(*Candidate.IndexResult);
         Origin |= Candidate.IndexResult->Origin;
         FromIndex = true;
+        if (!Candidate.IndexResult->Type.empty())
+          Relevance.HadSymbolType |= true;
+        if (PreferredType &&
+            PreferredType->raw() == Candidate.IndexResult->Type) {
+          Relevance.TypeMatchesPreferred = true;
+        }
       }
       if (Candidate.SemaResult) {
         Quality.merge(*Candidate.SemaResult);
         Relevance.merge(*Candidate.SemaResult);
+        if (PreferredType) {
+          if (auto CompletionType = OpaqueType::fromCompletionResult(
+                  Recorder->CCSema->getASTContext(), *Candidate.SemaResult)) {
+            Relevance.HadSymbolType |= true;
+            if (PreferredType == CompletionType)
+              Relevance.TypeMatchesPreferred = true;
+          }
+        }
         Origin |= SymbolOrigin::AST;
       }
     }
diff --git a/clang-tools-extra/clangd/Quality.cpp b/clang-tools-extra/clangd/Quality.cpp
index 640f543275d..cb1f64adabc 100644
--- a/clang-tools-extra/clangd/Quality.cpp
+++ b/clang-tools-extra/clangd/Quality.cpp
@@ -369,6 +369,9 @@ float SymbolRelevanceSignals::evaluate() const {
     }
   }
 
+  if (TypeMatchesPreferred)
+    Score *= 5.0;
+
   // Penalize non-instance members when they are accessed via a class instance.
   if (!IsInstanceMember &&
       (Context == CodeCompletionContext::CCC_DotMemberAccess ||
@@ -412,6 +415,10 @@ raw_ostream &operator<<(raw_ostream &OS, const SymbolRelevanceSignals &S) {
     OS << formatv("\tIndex scope boost: {0}\n",
                   scopeBoost(*S.ScopeProximityMatch, S.SymbolScope));
 
+  OS << formatv(
+      "\tType matched preferred: {0} (Context type: {1}, Symbol type: {2}\n",
+      S.TypeMatchesPreferred, S.HadContextType, S.HadSymbolType);
+
   return OS;
 }
 
diff --git a/clang-tools-extra/clangd/Quality.h b/clang-tools-extra/clangd/Quality.h
index d7185564077..f85e427fbe1 100644
--- a/clang-tools-extra/clangd/Quality.h
+++ b/clang-tools-extra/clangd/Quality.h
@@ -28,6 +28,7 @@
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_QUALITY_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_QUALITY_H
 
+#include "ExpectedTypes.h"
 #include "FileDistance.h"
 #include "clang/Sema/CodeCompleteConsumer.h"
 #include "llvm/ADT/ArrayRef.h"
@@ -122,6 +123,13 @@ struct SymbolRelevanceSignals {
   // Whether symbol is an instance member of a class.
   bool IsInstanceMember = false;
 
+  // Whether clang provided a preferred type in the completion context.
+  bool HadContextType = false;
+  // Whether a source completion item or a symbol had a type information.
+  bool HadSymbolType = false;
+  // Whether the item matches the type expected in the completion context.
+  bool TypeMatchesPreferred = false;
+
   void merge(const CodeCompletionResult &SemaResult);
   void merge(const Symbol &IndexResult);
 
diff --git a/clang-tools-extra/clangd/index/Index.h b/clang-tools-extra/clangd/index/Index.h
index 0c1d58617dd..11c117613ce 100644
--- a/clang-tools-extra/clangd/index/Index.h
+++ b/clang-tools-extra/clangd/index/Index.h
@@ -494,6 +494,8 @@ struct FuzzyFindRequest {
   /// Paths should be absolute.
   std::vector<std::string> ProximityPaths;
 
+  // FIXME(ibiryukov): add expected type to the request.
+
   bool operator==(const FuzzyFindRequest &Req) const {
     return std::tie(Query, Scopes, Limit, RestrictForCodeCompletion,
                     ProximityPaths) ==