Add document outline symbols from unnamed contexts, e.g. extern "C".

It is necessary to traverse children of unnamed declaration contexts
to get symbols which are currently missing in document outline, e.g.:

extern "C" {
void foo();
}

Reviewed By: kadircet

Differential Revision: https://reviews.llvm.org/D84839

diff --git a/clang-tools-extra/clangd/FindSymbols.cpp b/clang-tools-extra/clangd/FindSymbols.cpp
index f5d6a95..2471656 100644 (file)
--- a/clang-tools-extra/clangd/FindSymbols.cpp
+++ b/clang-tools-extra/clangd/FindSymbols.cpp
@@ -188,7 +188,7 @@ public:
   }
 
 private:
-  enum class VisitKind { No, OnlyDecl, DeclAndChildren };
+  enum class VisitKind { No, OnlyDecl, OnlyChildren, DeclAndChildren };
 
   void traverseDecl(Decl *D, std::vector<DocumentSymbol> &Results) {
     if (auto *Templ = llvm::dyn_cast<TemplateDecl>(D)) {
@@ -196,18 +196,25 @@ private:
       if (auto *TD = Templ->getTemplatedDecl())
         D = TD;
     }
-    auto *ND = llvm::dyn_cast<NamedDecl>(D);
-    if (!ND)
-      return;
-    VisitKind Visit = shouldVisit(ND);
+
+    VisitKind Visit = shouldVisit(D);
     if (Visit == VisitKind::No)
       return;
-    llvm::Optional<DocumentSymbol> Sym = declToSym(AST.getASTContext(), *ND);
+
+    if (Visit == VisitKind::OnlyChildren)
+      return traverseChildren(D, Results);
+
+    auto *ND = llvm::cast<NamedDecl>(D);
+    auto Sym = declToSym(AST.getASTContext(), *ND);
     if (!Sym)
       return;
-    if (Visit == VisitKind::DeclAndChildren)
-      traverseChildren(D, Sym->children);
     Results.push_back(std::move(*Sym));
+
+    if (Visit == VisitKind::OnlyDecl)
+      return;
+
+    assert(Visit == VisitKind::DeclAndChildren && "Unexpected VisitKind");
+    traverseChildren(ND, Results.back().children);
   }
 
   void traverseChildren(Decl *D, std::vector<DocumentSymbol> &Results) {
@@ -218,10 +225,16 @@ private:
       traverseDecl(C, Results);
   }
 
-  VisitKind shouldVisit(NamedDecl *D) {
+  VisitKind shouldVisit(Decl *D) {
     if (D->isImplicit())
       return VisitKind::No;
 
+    if (llvm::isa<LinkageSpecDecl>(D) || llvm::isa<ExportDecl>(D))
+      return VisitKind::OnlyChildren;
+
+    if (!llvm::isa<NamedDecl>(D))
+      return VisitKind::No;
+
     if (auto Func = llvm::dyn_cast<FunctionDecl>(D)) {
       // Some functions are implicit template instantiations, those should be
       // ignored.

diff --git a/clang-tools-extra/clangd/unittests/FindSymbolsTests.cpp b/clang-tools-extra/clangd/unittests/FindSymbolsTests.cpp
index 07c42fc..8576e11 100644 (file)
--- a/clang-tools-extra/clangd/unittests/FindSymbolsTests.cpp
+++ b/clang-tools-extra/clangd/unittests/FindSymbolsTests.cpp
@@ -429,6 +429,40 @@ TEST(DocumentSymbols, ExternSymbol) {
   EXPECT_THAT(getSymbols(TU.build()), IsEmpty());
 }
 
+TEST(DocumentSymbols, ExternContext) {
+  TestTU TU;
+  TU.Code = R"cpp(
+      extern "C" {
+      void foo();
+      class Foo {};
+      }
+      namespace ns {
+        extern "C" {
+        void bar();
+        class Bar {};
+        }
+      })cpp";
+
+  EXPECT_THAT(getSymbols(TU.build()),
+              ElementsAre(WithName("foo"), WithName("Foo"),
+                          AllOf(WithName("ns"),
+                                Children(WithName("bar"), WithName("Bar")))));
+}
+
+TEST(DocumentSymbols, ExportContext) {
+  TestTU TU;
+  TU.ExtraArgs = {"-std=c++20"};
+  TU.Code = R"cpp(
+      export module test;
+      export {
+      void foo();
+      class Foo {};
+      })cpp";
+
+  EXPECT_THAT(getSymbols(TU.build()),
+              ElementsAre(WithName("foo"), WithName("Foo")));
+}
+
 TEST(DocumentSymbols, NoLocals) {
   TestTU TU;
   TU.Code = R"cpp(