[clangd] Incorporate transitive #includes into code complete proximity scoring.

Summary:
We now compute a distance from the main file to the symbol header, which
is a weighted count of:
 - some number of #include traversals from source file --> included file
 - some number of FS traversals from file --> parent directory
 - some number of FS traversals from parent directory --> child file/dir
This calculation is performed in the appropriate URI scheme.

This means we'll get some proximity boost from header files in main-file
contexts, even when these are in different directory trees.

This extended file proximity model is not yet incorporated in the index
interface/implementation.

Reviewers: ioeric

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

Differential Revision: https://reviews.llvm.org/D48441

llvm-svn: 336177

1 files changed, 3 insertions, 4 deletions

diff --git a/clang-tools-extra/clangd/XRefs.cpp b/clang-tools-extra/clangd/XRefs.cpp
index 92fe8d268b2..6cc661a20bc 100644
--- a/clang-tools-extra/clangd/XRefs.cpp
+++ b/clang-tools-extra/clangd/XRefs.cpp
@@ -230,13 +230,10 @@ llvm::Optional<SymbolID> getSymbolID(const Decl *D) {
 std::vector<Location> findDefinitions(ParsedAST &AST, Position Pos,
                                       const SymbolIndex *Index) {
   const SourceManager &SourceMgr = AST.getASTContext().getSourceManager();
-  SourceLocation SourceLocationBeg =
-      getBeginningOfIdentifier(AST, Pos, SourceMgr.getMainFileID());
 
   std::vector<Location> Result;
   // Handle goto definition for #include.
-  for (auto &Inc : AST.getInclusions()) {
-    Position Pos = sourceLocToPosition(SourceMgr, SourceLocationBeg);
+  for (auto &Inc : AST.getIncludeStructure().MainFileIncludes) {
     if (!Inc.Resolved.empty() && Inc.R.contains(Pos))
       Result.push_back(Location{URIForFile{Inc.Resolved}, {}});
   }
@@ -244,6 +241,8 @@ std::vector<Location> findDefinitions(ParsedAST &AST, Position Pos,
     return Result;
 
   // Identified symbols at a specific position.
+  SourceLocation SourceLocationBeg =
+      getBeginningOfIdentifier(AST, Pos, SourceMgr.getMainFileID());
   auto Symbols = getSymbolAtPosition(AST, SourceLocationBeg);
 
   for (auto Item : Symbols.Macros) {