[clang] [clang][Sema] Unwrap reference types in HeuristicResolverImpl::resolveTypeToRecordDecl() (PR #124451)

[Nathan Ridge via cfe-commits]

https://github.com/HighCommander4 created https://github.com/llvm/llvm-project/pull/124451

Partially fixes https://github.com/llvm/llvm-project/issues/124450

>From 9c8349f994f8c66f07be79834352fbe25301ef43 Mon Sep 17 00:00:00 2001
From: Nathan Ridge <zeratul976 at hotmail.com>
Date: Sun, 26 Jan 2025 02:04:45 -0500
Subject: [PATCH] [clang][Sema] Unwrap reference types in
 HeuristicResolverImpl::resolveTypeToRecordDecl()

Partially fixes https://github.com/llvm/llvm-project/issues/124450
---
 clang/lib/Sema/HeuristicResolver.cpp          |  4 ++--
 .../unittests/Sema/HeuristicResolverTest.cpp  | 21 +++++++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/HeuristicResolver.cpp b/clang/lib/Sema/HeuristicResolver.cpp
index e893afed71d268..6157191bafa6fc 100644
--- a/clang/lib/Sema/HeuristicResolver.cpp
+++ b/clang/lib/Sema/HeuristicResolver.cpp
@@ -133,8 +133,8 @@ TemplateName getReferencedTemplateName(const Type *T) {
 CXXRecordDecl *HeuristicResolverImpl::resolveTypeToRecordDecl(const Type *T) {
   assert(T);
 
-  // Unwrap type sugar such as type aliases.
-  T = T->getCanonicalTypeInternal().getTypePtr();
+  // Unwrap references and type sugar such as type aliases.
+  T = T->getCanonicalTypeInternal().getNonReferenceType().getTypePtr();
 
   if (const auto *DNT = T->getAs<DependentNameType>()) {
     T = resolveDeclsToType(resolveDependentNameType(DNT), Ctx)
diff --git a/clang/unittests/Sema/HeuristicResolverTest.cpp b/clang/unittests/Sema/HeuristicResolverTest.cpp
index 2b775b11719ea7..00e19aecdae0a9 100644
--- a/clang/unittests/Sema/HeuristicResolverTest.cpp
+++ b/clang/unittests/Sema/HeuristicResolverTest.cpp
@@ -213,6 +213,27 @@ TEST(HeuristicResolver, MemberExpr_Chained) {
       cxxMethodDecl(hasName("foo")).bind("output"));
 }
 
+TEST(HeuristicResolver, MemberExpr_ReferenceType) {
+  std::string Code = R"cpp(
+    struct B {
+      int waldo;
+    };
+    template <typename T>
+    struct A {
+      B &b;
+    };
+    template <typename T>
+    void foo(A<T> &a) {
+      a.b.waldo;
+    }
+  )cpp";
+  // Test resolution of "waldo" in "a.b.waldo".
+  expectResolution(
+      Code, &HeuristicResolver::resolveMemberExpr,
+      cxxDependentScopeMemberExpr(hasMemberName("waldo")).bind("input"),
+      fieldDecl(hasName("waldo")).bind("output"));
+}
+
 TEST(HeuristicResolver, MemberExpr_TemplateArgs) {
   std::string Code = R"cpp(
     struct Foo {