[clangd] Collect name references in the index.

[hokein]

Summary

This is used for cross-file rename. When renaming a class, we expect to
rename all related constructors/destructors.

[ilya-biryukov]

LGTM.

clang-tools-extra/clangd/unittests/SymbolCollectorTests.cpp

633

maybe use unnamed ranges?
having $foo[[]] instead of [[]] only hurt readability

[kadircet]

clang-tools-extra/clangd/index/SymbolCollector.cpp

268

This also implies that find refs on a class type will also report locations for constructors and destructors. I believe that's the behavior we decided to have in our offline discussions, just statin in here for future reference.

[merge_guards_bot]

Build result: fail - 59565 tests passed, 2 failed and 805 were skipped.

failed: LLVM.tools/llvm-ar/mri-utf8.test
failed: LLVM.tools/llvm-objdump/X86/disassemble-functions.test

Log files: cmake-log.txt, ninja_check_all-log.txt, CMakeCache.txt

[hokein]

address comment.

[merge_guards_bot]

Build result: fail - 59566 tests passed, 1 failed and 805 were skipped.

failed: LLVM.tools/llvm-ar/mri-utf8.test

Log files: cmake-log.txt, ninja_check_all-log.txt, CMakeCache.txt

clang-tools-extra/clangd/index/SymbolCollector.cpp

if (D->getLocation().isInvalid())
     D = ASTNode.OrigD;
   // If OrigD is an declaration associated with a friend declaration and it's
   // not a definition, skip it. Note that OrigD is the occurrence that the
   // collector is currently visiting.
   if ((ASTNode.OrigD->getFriendObjectKind() !=
        Decl::FriendObjectKind::FOK_None) &&
       !(Roles & static_cast<unsigned>(index::SymbolRole::Definition)))
     return true;
-  // Skip non-semantic references, we should start processing these when we
-  // decide to implement renaming with index support.
-  if ((Roles & static_cast<unsigned>(index::SymbolRole::NameReference)))
-    return true;
   // A declaration created for a friend declaration should not be used as the
   // canonical declaration in the index. Use OrigD instead, unless we've already
   // picked a replacement for D
   if (D->getFriendObjectKind() != Decl::FriendObjectKind::FOK_None)
     D = CanonicalDecls.try_emplace(D, ASTNode.OrigD).first->second;
   const NamedDecl *ND = dyn_cast<NamedDecl>(D);
   if (!ND)
     return true;

clang-tools-extra/clangd/unittests/SymbolCollectorTests.cpp

TEST_F(SymbolCollectorTest, Refs) {
   // Symbols *only* in the main file (a, b, c) had no refs collected.
   auto MainSymbols =
       TestTU::withHeaderCode(SymbolsOnlyInMainCode.code()).headerSymbols();
   EXPECT_THAT(Refs, Not(Contains(Pair(findSymbol(MainSymbols, "a").ID, _))));
   EXPECT_THAT(Refs, Not(Contains(Pair(findSymbol(MainSymbols, "b").ID, _))));
   EXPECT_THAT(Refs, Not(Contains(Pair(findSymbol(MainSymbols, "c").ID, _))));
 }
 
+TEST_F(SymbolCollectorTest, NameReferences) {
+  CollectorOpts.RefFilter = RefKind::All;
+  CollectorOpts.RefsInHeaders = true;
+  Annotations Header(R"(
+    class [[Foo]] {
+    public:
+      [[Foo]]() {}
+      ~[[Foo]]() {}
+    };
+  )");
+  CollectorOpts.RefFilter = RefKind::All;
+  runSymbolCollector(Header.code(), "");
+  // When we find references for class Foo, we expect to see all
+  // constructor/destructor references.
+  EXPECT_THAT(Refs, Contains(Pair(findSymbol(Symbols, "Foo").ID,
+                                  HaveRanges(Header.ranges()))));
+}
 
 TEST_F(SymbolCollectorTest, HeaderAsMainFile) {
   CollectorOpts.RefFilter = RefKind::All;
   Annotations Header(R"(
   class $Foo[[Foo]] {};
 
   void $Func[[Func]]() {
     $Foo[[Foo]] fo;