[llvm-branch-commits] [clang-tools-extra] 3ae25b7 - [clangd] findNearbyIdentifier(): fix the word search in the token stream.

[Hans Wennborg via llvm-branch-commits]

Author: Aleksandr Platonov
Date: 2020-08-03T15:43:05+02:00
New Revision: 3ae25b7a09ded12ff63acec0efcf8c7d715114fe

URL: https://github.com/llvm/llvm-project/commit/3ae25b7a09ded12ff63acec0efcf8c7d715114fe
DIFF: https://github.com/llvm/llvm-project/commit/3ae25b7a09ded12ff63acec0efcf8c7d715114fe.diff

LOG: [clangd] findNearbyIdentifier(): fix the word search in the token stream.

Without this patch the word occurrence search always returns the first token of the file.
Despite of that, `findNeardyIdentifier()` returns the correct result (but inefficently) until there are several matched tokens with the same value `floor(log2(<token line> - <word line>))` (e.g. several matched tokens on the same line).

Reviewed By: kadircet

Differential Revision: https://reviews.llvm.org/D84912

(cherry picked from commit 05b173466142596b3297ab02e423574cb74b3799)

Added: 
    

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

Removed: 
    


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diff  --git a/clang-tools-extra/clangd/XRefs.cpp b/clang-tools-extra/clangd/XRefs.cpp
index c208e953f2ab..2a82dfd66499 100644
--- a/clang-tools-extra/clangd/XRefs.cpp
+++ b/clang-tools-extra/clangd/XRefs.cpp
@@ -518,7 +518,7 @@ const syntax::Token *findNearbyIdentifier(const SpelledWord &Word,
   // Find where the word occurred in the token stream, to search forward & back.
   auto *I = llvm::partition_point(SpelledTokens, [&](const syntax::Token &T) {
     assert(SM.getFileID(T.location()) == SM.getFileID(Word.Location));
-    return T.location() >= Word.Location; // Comparison OK: same file.
+    return T.location() < Word.Location; // Comparison OK: same file.
   });
   // Search for matches after the cursor.
   for (const syntax::Token &Tok : llvm::makeArrayRef(I, SpelledTokens.end()))

diff  --git a/clang-tools-extra/clangd/unittests/XRefsTests.cpp b/clang-tools-extra/clangd/unittests/XRefsTests.cpp
index 0428303f5b0a..0a8f85ed5317 100644
--- a/clang-tools-extra/clangd/unittests/XRefsTests.cpp
+++ b/clang-tools-extra/clangd/unittests/XRefsTests.cpp
@@ -1197,7 +1197,14 @@ TEST(LocateSymbol, NearbyIdentifier) {
 
       // h^i
     )cpp",
-  };
+      R"cpp(
+      // prefer nearest occurrence even if several matched tokens
+      // have the same value of `floor(log2(<token line> - <word line>))`.
+      int hello;
+      int x = hello, y = hello;
+      int z = [[hello]];
+      // h^ello
+    )cpp"};
   for (const char *Test : Tests) {
     Annotations T(Test);
     auto AST = TestTU::withCode(T.code()).build();