[clang] [RecursiveASTVisitor] Fix RecursiveASTVisitor (RAV) fails to visit the initializer of a bitfield (PR #69557)

[Shivam Gupta via cfe-commits]

https://github.com/xgupta created https://github.com/llvm/llvm-project/pull/69557

This fixes https://github.com/llvm/llvm-project/issues/64916.

Patch by Scott McPeak

>From 96f6b90ed4a70430f94eab2d9ca317dd8367022a Mon Sep 17 00:00:00 2001
From: Shivam Gupta <shivam98.tkg at gmail.com>
Date: Thu, 19 Oct 2023 09:06:43 +0530
Subject: [PATCH] [RecursiveASTVisitor] Fix RecursiveASTVisitor (RAV) fails to
 visit the initializer of a bitfield

Patch by Scott McPeak
---
 clang/include/clang/AST/RecursiveASTVisitor.h |  2 +-
 clang/unittests/Tooling/CMakeLists.txt        |  1 +
 .../BitfieldInitializer.cpp                   | 34 +++++++++++++++++++
 3 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 clang/unittests/Tooling/RecursiveASTVisitorTests/BitfieldInitializer.cpp

diff --git a/clang/include/clang/AST/RecursiveASTVisitor.h b/clang/include/clang/AST/RecursiveASTVisitor.h
index 3dd23eb38eeabfc..53bc15e1b19f668 100644
--- a/clang/include/clang/AST/RecursiveASTVisitor.h
+++ b/clang/include/clang/AST/RecursiveASTVisitor.h
@@ -2103,7 +2103,7 @@ DEF_TRAVERSE_DECL(FieldDecl, {
   TRY_TO(TraverseDeclaratorHelper(D));
   if (D->isBitField())
     TRY_TO(TraverseStmt(D->getBitWidth()));
-  else if (D->hasInClassInitializer())
+  if (D->hasInClassInitializer())
     TRY_TO(TraverseStmt(D->getInClassInitializer()));
 })
 
diff --git a/clang/unittests/Tooling/CMakeLists.txt b/clang/unittests/Tooling/CMakeLists.txt
index 2fbe78e3fab7528..5a10a6b285390e9 100644
--- a/clang/unittests/Tooling/CMakeLists.txt
+++ b/clang/unittests/Tooling/CMakeLists.txt
@@ -25,6 +25,7 @@ add_clang_unittest(ToolingTests
   QualTypeNamesTest.cpp
   RangeSelectorTest.cpp
   RecursiveASTVisitorTests/Attr.cpp
+  RecursiveASTVisitorTests/BitfieldInitializer.cpp
   RecursiveASTVisitorTests/CallbacksLeaf.cpp
   RecursiveASTVisitorTests/CallbacksUnaryOperator.cpp
   RecursiveASTVisitorTests/CallbacksBinaryOperator.cpp
diff --git a/clang/unittests/Tooling/RecursiveASTVisitorTests/BitfieldInitializer.cpp b/clang/unittests/Tooling/RecursiveASTVisitorTests/BitfieldInitializer.cpp
new file mode 100644
index 000000000000000..676a491a43040ea
--- /dev/null
+++ b/clang/unittests/Tooling/RecursiveASTVisitorTests/BitfieldInitializer.cpp
@@ -0,0 +1,34 @@
+//===- unittest/Tooling/RecursiveASTVisitorTests/BitfieldInitializer.cpp -===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "TestVisitor.h"
+#include <string>
+
+using namespace clang;
+
+namespace {
+
+// Check to ensure that bitfield initializers are visited.
+class BitfieldInitializerVisitor : public ExpectedLocationVisitor<BitfieldInitializerVisitor> {
+public:
+  bool VisitIntegerLiteral(IntegerLiteral *IL) {
+    Match(std::to_string(IL->getValue().getSExtValue()), IL->getLocation());
+    return true;
+  }
+};
+
+TEST(RecursiveASTVisitor, BitfieldInitializerIsVisited) {
+  BitfieldInitializerVisitor Visitor;
+  Visitor.ExpectMatch("123", 2, 15); 
+  EXPECT_TRUE(Visitor.runOver(
+    "struct S {\n"
+    "  int x : 8 = 123;\n"
+    "};\n"));
+}
+
+} // end anonymous namespace