[clang-tools-extra] [clangd] Add hover support for statement attributes (PR #214318)

[Maria Fernanda Guimarães via cfe-commits]

https://github.com/mafeguimaraes updated https://github.com/llvm/llvm-project/pull/214318

>From e49be6731684044b85c11c3b4893b8cc2f890906 Mon Sep 17 00:00:00 2001
From: Maria Fernanda Guimaraes <mariafefe201 at gmail.com>
Date: Wed, 5 Aug 2026 18:10:16 +0000
Subject: [PATCH 1/2] Add hover support for HLSL statement attributes

---
 clang-tools-extra/clangd/Selection.cpp        |  8 +++
 .../clangd/unittests/HoverTests.cpp           | 60 +++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/clang-tools-extra/clangd/Selection.cpp b/clang-tools-extra/clangd/Selection.cpp
index b79ffc7d5a6e9..41d028cfcf4b5 100644
--- a/clang-tools-extra/clangd/Selection.cpp
+++ b/clang-tools-extra/clangd/Selection.cpp
@@ -666,6 +666,14 @@ class SelectionVisitor : public RecursiveASTVisitor<SelectionVisitor> {
   bool TraverseAttr(Attr *X) {
     return traverseNode(X, [&] { return Base::TraverseAttr(X); });
   }
+  bool TraverseAttributedStmt(AttributedStmt *S) {
+    return traverseNode(S, [&] {
+      for (const Attr *A : S->getAttrs())
+        if (!TraverseAttr(const_cast<Attr *>(A)))
+          return false;
+      return TraverseStmt(S->getSubStmt());
+    });
+  }
   bool TraverseConceptReference(ConceptReference *X) {
     return traverseNode(X, [&] { return Base::TraverseConceptReference(X); });
   }
diff --git a/clang-tools-extra/clangd/unittests/HoverTests.cpp b/clang-tools-extra/clangd/unittests/HoverTests.cpp
index e6ad6acc6ea54..4f557ad3162fb 100644
--- a/clang-tools-extra/clangd/unittests/HoverTests.cpp
+++ b/clang-tools-extra/clangd/unittests/HoverTests.cpp
@@ -5411,7 +5411,67 @@ TEST(Hover, HLSLInvalidVectorSwizzleNoCrash) {
   auto H = getHover(AST, T.point(), format::getLLVMStyle(), nullptr);
   EXPECT_FALSE(H);
 }
+TEST(Hover, HLSLControlFlowAndLoopHints) {
+  struct {
+    const char *const Code;
+    const std::function<void(HoverInfo &)> ExpectedBuilder;
+  } Cases[] = {{
+                   R"hlsl(
+            [numthreads(1, 1, 1)]
+            void main() {
+              [^unroll]
+              for (int i = 0; i < 4; i++) {}
+            }
+          )hlsl",
+                   [](HoverInfo &HI) { HI.Name = "unroll"; }},
+               {
+                   R"hlsl(
+            [numthreads(1, 1, 1)]
+            void main() {
+              [l^oop]
+              for (int i = 0; i < 4; i++) {}
+            }
+          )hlsl",
+                   [](HoverInfo &HI) { HI.Name = "loop"; }},
+               {
+                   R"hlsl(
+            [numthreads(1, 1, 1)]
+            void main() {
+              [b^ranch]
+              if (true) {}
+            }
+          )hlsl",
+                   [](HoverInfo &HI) { HI.Name = "branch"; }},
+               {
+                   R"hlsl(
+            [numthreads(1, 1, 1)]
+            void main() {
+              [f^latten]
+              if (true) {}
+            }
+          )hlsl",
+                   [](HoverInfo &HI) { HI.Name = "flatten"; }}};
+
+  for (const auto &Case : Cases) {
+    SCOPED_TRACE(Case.Code);
+    Annotations T(Case.Code);
+    TestTU TU = TestTU::withCode(T.code());
+    configureHLSL(TU);
+    auto AST = TU.build();
+
+    auto H = getHover(AST, T.point(), format::getLLVMStyle(), nullptr);
+    ASSERT_TRUE(H);
 
+    HoverInfo Expected;
+    Case.ExpectedBuilder(Expected);
+
+    EXPECT_EQ(H->Name, Expected.Name);
+
+    if (Expected.Name == "unroll" || Expected.Name == "loop") {
+      EXPECT_FALSE(H->Documentation.empty());
+    }
+  }
+}
 } // namespace
 } // namespace clangd
 } // namespace clang

>From 0e4debbb76d8f7b29f2d5d828696a0e1b24cff8d Mon Sep 17 00:00:00 2001
From: Maria Fernanda Guimaraes <mariafefe201 at gmail.com>
Date: Wed, 5 Aug 2026 21:15:34 +0000
Subject: [PATCH 2/2] Add hover tests for C++ statement attributes

---
 .../clangd/unittests/HoverTests.cpp           | 48 +++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/clang-tools-extra/clangd/unittests/HoverTests.cpp b/clang-tools-extra/clangd/unittests/HoverTests.cpp
index 4f557ad3162fb..4fd7aee16dc34 100644
--- a/clang-tools-extra/clangd/unittests/HoverTests.cpp
+++ b/clang-tools-extra/clangd/unittests/HoverTests.cpp
@@ -5472,6 +5472,54 @@ TEST(Hover, HLSLControlFlowAndLoopHints) {
     }
   }
 }
+
+TEST(Hover, CXXStatementAttributes) {
+  struct {
+    const char *const Code;
+    const char *const Target;
+    const char *const ExpectedName;
+  } Cases[] = {{
+                   R"cpp(
+            void foo() {
+              [[likely]] if (true) {}
+            }
+          )cpp",
+                   "likely", "likely"},
+               {
+                   R"cpp(
+            void foo() {
+              [[unlikely]] if (true) {}
+            }
+          )cpp",
+                   "unlikely", "unlikely"},
+               {
+                   R"cpp(
+            void foo() {
+              switch (1) {
+              case 1:
+                [[fallthrough]];
+              case 2:
+                break;
+              }
+            }
+          )cpp",
+                   "fallthrough", "fallthrough"}};
+
+  for (const auto &Case : Cases) {
+    SCOPED_TRACE(Case.Code);
+    TestTU TU = TestTU::withCode(Case.Code);
+    TU.ExtraArgs.push_back("-std=c++20");
+    auto AST = TU.build();
+
+    llvm::StringRef Code = Case.Code;
+    size_t Offset = Code.find(Case.Target);
+    Position P = offsetToPosition(Code, Offset);
+
+    auto H = getHover(AST, P, format::getLLVMStyle(), nullptr);
+    ASSERT_TRUE(H);
+    EXPECT_EQ(H->Name, Case.ExpectedName);
+  }
+}
 } // namespace
 } // namespace clangd
 } // namespace clang