[PATCH] D76098: [WIP] [clangd] Do not trigger go-to-def textual fallback inside string literals

[Nathan Ridge via Phabricator via cfe-commits]

nridge created this revision.
nridge added a reviewer: sammccall.
Herald added subscribers: cfe-commits, usaxena95, kadircet, arphaman, jkorous, MaskRay, ilya-biryukov.
Herald added a project: clang.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D76098

Files:
  clang-tools-extra/clangd/XRefs.cpp
  clang-tools-extra/clangd/unittests/XRefsTests.cpp


Index: clang-tools-extra/clangd/unittests/XRefsTests.cpp
===================================================================
--- clang-tools-extra/clangd/unittests/XRefsTests.cpp
+++ clang-tools-extra/clangd/unittests/XRefsTests.cpp
@@ -624,11 +624,12 @@
 TEST(LocateSymbol, Textual) {
   const char *Tests[] = {
       R"cpp(// Comment
-        struct [[MyClass]] {};
-        // Comment mentioning M^yClass
-      )cpp",
+      struct [[MyClass]] {};
+      // Comment mentioning M^yClass
+    )cpp",
       R"cpp(// String
-        struct [[MyClass]] {};
+        struct MyClass {};
+        // Not triggered for string literal tokens.
         const char* s = "String literal mentioning M^yClass";
       )cpp",
       R"cpp(// Ifdef'ed out code
@@ -680,7 +681,7 @@
       EXPECT_EQ(Results[0].PreferredDeclaration.range, *WantDecl) << Test;
     }
   }
-}
+} // namespace
 
 TEST(LocateSymbol, Ambiguous) {
   auto T = Annotations(R"cpp(
Index: clang-tools-extra/clangd/XRefs.cpp
===================================================================
--- clang-tools-extra/clangd/XRefs.cpp
+++ clang-tools-extra/clangd/XRefs.cpp
@@ -355,6 +355,20 @@
   return !WordExpandedTokens.empty();
 }
 
+enum TokenFlavor { Identifier, Comment, Other };
+
+TokenFlavor getTokenFlavor(SourceLocation Loc, const SourceManager &SM,
+                           const LangOptions &LangOpts) {
+  Token Tok;
+  if (Lexer::getRawToken(Loc, Tok, SM, LangOpts))
+    return Other;
+  if (Tok.is(tok::TokenKind::raw_identifier))
+    return Identifier;
+  if (Tok.is(tok::TokenKind::comment))
+    return Comment;
+  return Other;
+}
+
 } // namespace
 
 std::vector<LocatedSymbol>
@@ -363,6 +377,11 @@
                              const std::string &MainFilePath) {
   const auto &SM = AST.getSourceManager();
 
+  TokenFlavor Flavor = getTokenFlavor(Loc, SM, AST.getLangOpts());
+  // Only consider comment and (raw) identifier tokens.
+  if (!(Flavor == TokenFlavor::Comment || Flavor == TokenFlavor::Identifier))
+    return {};
+
   // Get the raw word at the specified location.
   unsigned Pos;
   FileID File;
@@ -374,12 +393,14 @@
   unsigned WordOffset = Word.data() - Code.data();
   SourceLocation WordStart = SM.getComposedLoc(File, WordOffset);
 
-  // Do not consider tokens that survived preprocessing.
-  // We are erring on the safe side here, as a user may expect to get
-  // accurate (as opposed to textual-heuristic) results for such tokens.
+  // If this is an identifier token, do not consider if it it survived
+  // preprocessing. We are erring on the safe side here, as a user may expect to
+  // get accurate (as opposed to textual-heuristic) results for such tokens.
   // FIXME: Relax this for dependent code.
-  if (tokenSurvivedPreprocessing(WordStart, AST.getTokens()))
+  if (Flavor == TokenFlavor::Identifier &&
+      tokenSurvivedPreprocessing(WordStart, AST.getTokens())) {
     return {};
+  }
 
   // Additionally filter for signals that the word is likely to be an
   // identifier. This avoids triggering on e.g. random words in a comment.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D76098.250052.patch
Type: text/x-patch
Size: 3065 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20200312/a0559602/attachment-0001.bin>