[clangd] Boost completion score according to file proximity.

Summary:
Also move unittest: URI scheme to TestFS so that it can be shared by
different tests.

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: ilya-biryukov, MaskRay, jkorous, cfe-commits

Differential Revision: https://reviews.llvm.org/D47935

llvm-svn: 334810

1 files changed, 30 insertions, 1 deletions

diff --git a/clang-tools-extra/clangd/Quality.h b/clang-tools-extra/clangd/Quality.h
index 0e0b6df6ba8..fef039a3a2f 100644
--- a/clang-tools-extra/clangd/Quality.h
+++ b/clang-tools-extra/clangd/Quality.h
@@ -26,6 +26,7 @@
 //===---------------------------------------------------------------------===//
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_QUALITY_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_QUALITY_H
+#include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringRef.h"
 #include <algorithm>
 #include <functional>
@@ -68,13 +69,22 @@ struct SymbolQualitySignals {
 llvm::raw_ostream &operator<<(llvm::raw_ostream &,
                               const SymbolQualitySignals &);
 
+class FileProximityMatcher;
+
 /// Attributes of a symbol-query pair that affect how much we like it.
 struct SymbolRelevanceSignals {
   /// 0-1+ fuzzy-match score for unqualified name. Must be explicitly assigned.
   float NameMatch = 1;
   bool Forbidden = false; // Unavailable (e.g const) or inaccessible (private).
+
+  const FileProximityMatcher *FileProximityMatch = nullptr;
+  /// This is used to calculate proximity between the index symbol and the
+  /// query.
+  llvm::StringRef SymbolURI;
   /// Proximity between best declaration and the query. [0-1], 1 is closest.
-  float ProximityScore = 0;
+  /// FIXME: unify with index proximity score - signals should be
+  /// source-independent.
+  float SemaProximityScore = 0;
 
   // An approximate measure of where we expect the symbol to be used.
   enum AccessibleScope {
@@ -101,6 +111,25 @@ llvm::raw_ostream &operator<<(llvm::raw_ostream &,
 /// Combine symbol quality and relevance into a single score.
 float evaluateSymbolAndRelevance(float SymbolQuality, float SymbolRelevance);
 
+class FileProximityMatcher {
+  public:
+    /// \p ProximityPaths are used to compute proximity scores from symbol's
+    /// declaring file. The best score will be used.
+    explicit FileProximityMatcher(
+        llvm::ArrayRef<llvm::StringRef> ProximityPaths);
+
+    /// Calculates the best proximity score from proximity paths to the symbol's
+    /// URI. Score is [0-1], 1 means \p SymbolURI exactly matches a proximity
+    /// path. When a path cannot be encoded into the same scheme as \p
+    /// SymbolURI, the proximity will be 0.
+    float uriProximity(llvm::StringRef SymbolURI) const;
+
+  private:
+    llvm::SmallVector<std::string, 2> ProximityPaths;
+    friend llvm::raw_ostream &operator<<(llvm::raw_ostream &,
+                                         const FileProximityMatcher &);
+};
+
 /// TopN<T> is a lossy container that preserves only the "best" N elements.
 template <typename T, typename Compare = std::greater<T>> class TopN {
 public: