From 84bf607eac44ea32c9cb662c21ccd4c23da7e174 Mon Sep 17 00:00:00 2001
From: Kadir Cetinkaya <kadircet@google.com>
Date: Tue, 9 Oct 2018 08:41:12 +0000
Subject: [PATCH] [clangd] Revert back to previous heuristic for diagnostic
 range extraction.

Summary: Also add a few new test cases and a special case into handling of empty fixit ranges that  collides with location of a diag.

Reviewers: sammccall, ilya-biryukov

Reviewed By: sammccall

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

Differential Revision: https://reviews.llvm.org/D52889

llvm-svn: 344025
---
 clang-tools-extra/clangd/Diagnostics.cpp              |  8 ++------
 .../unittests/clangd/ClangdUnitTests.cpp              | 11 +++++++++--
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/clang-tools-extra/clangd/Diagnostics.cpp b/clang-tools-extra/clangd/Diagnostics.cpp
index a2f86eb949c9..b8ce2e0ed8e5 100644
--- a/clang-tools-extra/clangd/Diagnostics.cpp
+++ b/clang-tools-extra/clangd/Diagnostics.cpp
@@ -51,16 +51,12 @@ bool locationInRange(SourceLocation L, CharSourceRange R,
 Range diagnosticRange(const clang::Diagnostic &D, const LangOptions &L) {
   auto &M = D.getSourceManager();
   auto Loc = M.getFileLoc(D.getLocation());
-  // Accept the first range that contains the location.
-  llvm::Optional<Range> FallbackRange;
   for (const auto &CR : D.getRanges()) {
     auto R = Lexer::makeFileCharRange(CR, M, L);
     if (locationInRange(Loc, R, M))
       return halfOpenToRange(M, R);
-    // If there are no ranges that contain the location report the first range.
-    if (!FallbackRange)
-      FallbackRange = halfOpenToRange(M, R);
   }
+  llvm::Optional<Range> FallbackRange;
   // The range may be given as a fixit hint instead.
   for (const auto &F : D.getFixItHints()) {
     auto R = Lexer::makeFileCharRange(F.RemoveRange, M, L);
@@ -69,7 +65,7 @@ Range diagnosticRange(const clang::Diagnostic &D, const LangOptions &L) {
     // If there's a fixit that performs insertion, it has zero-width. Therefore
     // it can't contain the location of the diag, but it might be possible that
     // this should be reported as range. For example missing semicolon.
-    if (!FallbackRange && R.getBegin() == R.getEnd())
+    if (R.getBegin() == R.getEnd() && Loc == R.getBegin())
       FallbackRange = halfOpenToRange(M, R);
   }
   if (FallbackRange)
diff --git a/clang-tools-extra/unittests/clangd/ClangdUnitTests.cpp b/clang-tools-extra/unittests/clangd/ClangdUnitTests.cpp
index 51cfcfe48f38..fe3fc2006359 100644
--- a/clang-tools-extra/unittests/clangd/ClangdUnitTests.cpp
+++ b/clang-tools-extra/unittests/clangd/ClangdUnitTests.cpp
@@ -75,13 +75,17 @@ Position pos(int line, int character) {
 TEST(DiagnosticsTest, DiagnosticRanges) {
   // Check we report correct ranges, including various edge-cases.
   Annotations Test(R"cpp(
+    namespace test{};
     void $decl[[foo]]();
     int main() {
       $typo[[go\
 o]]();
       foo()$semicolon[[]]//with comments
       $unk[[unknown]]();
-      double bar = $type[["foo"]];
+      double $type[[bar]] = "foo";
+      struct Foo { int x; }; Foo a;
+      a.$nomember[[y]];
+      test::$nomembernamespace[[test]];
     }
   )cpp");
   EXPECT_THAT(
@@ -103,7 +107,10 @@ o]]();
           Diag(Test.range("unk"), "use of undeclared identifier 'unknown'"),
           Diag(Test.range("type"),
                "cannot initialize a variable of type 'double' with an lvalue "
-               "of type 'const char [4]'")));
+               "of type 'const char [4]'"),
+          Diag(Test.range("nomember"), "no member named 'y' in 'Foo'"),
+          Diag(Test.range("nomembernamespace"),
+               "no member named 'test' in namespace 'test'")));
 }
 
 TEST(DiagnosticsTest, FlagsMatter) {