[llvm-branch-commits] [clang] [clang-tools-extra] [clang][HeuristicResolver] Apply default argument heuristic in resolveDeclRefExpr as well (PR #132576)

[Nathan Ridge via llvm-branch-commits]

https://github.com/HighCommander4 updated https://github.com/llvm/llvm-project/pull/132576

>From 2c9fc17bf2ef28c42df472598e4b7d09297cb668 Mon Sep 17 00:00:00 2001
From: Nathan Ridge <zeratul976 at hotmail.com>
Date: Sat, 22 Mar 2025 20:54:02 -0400
Subject: [PATCH] [clang][HeuristicResolver] Apply default argument heuristic
 in resolveDeclRefExpr as well

---
 .../clangd/unittests/XRefsTests.cpp             |  2 +-
 clang/lib/Sema/HeuristicResolver.cpp            |  6 +++---
 clang/unittests/Sema/HeuristicResolverTest.cpp  | 17 +++++++++++++++++
 3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/clang-tools-extra/clangd/unittests/XRefsTests.cpp b/clang-tools-extra/clangd/unittests/XRefsTests.cpp
index e12d7691c58fb..693e965e78a96 100644
--- a/clang-tools-extra/clangd/unittests/XRefsTests.cpp
+++ b/clang-tools-extra/clangd/unittests/XRefsTests.cpp
@@ -1091,7 +1091,7 @@ TEST(LocateSymbol, All) {
       )objc",
       R"cpp(
         struct PointerIntPairInfo {
-          static void *getPointer(void *Value);
+          static void *$decl[[getPointer]](void *Value);
         };
 
         template <typename Info = PointerIntPairInfo> struct PointerIntPair {
diff --git a/clang/lib/Sema/HeuristicResolver.cpp b/clang/lib/Sema/HeuristicResolver.cpp
index 9b793e876a49f..5202ae340bbfd 100644
--- a/clang/lib/Sema/HeuristicResolver.cpp
+++ b/clang/lib/Sema/HeuristicResolver.cpp
@@ -315,9 +315,9 @@ std::vector<const NamedDecl *> HeuristicResolverImpl::resolveMemberExpr(
 
 std::vector<const NamedDecl *>
 HeuristicResolverImpl::resolveDeclRefExpr(const DependentScopeDeclRefExpr *RE) {
-  return resolveDependentMember(
-      resolveNestedNameSpecifierToType(RE->getQualifier()), RE->getDeclName(),
-      StaticFilter);
+  QualType Qualifier = resolveNestedNameSpecifierToType(RE->getQualifier());
+  Qualifier = simplifyType(Qualifier, nullptr, /*UnwrapPointer=*/false);
+  return resolveDependentMember(Qualifier, RE->getDeclName(), StaticFilter);
 }
 
 std::vector<const NamedDecl *>
diff --git a/clang/unittests/Sema/HeuristicResolverTest.cpp b/clang/unittests/Sema/HeuristicResolverTest.cpp
index f7eb4b23c2ab0..3ed6bba790be3 100644
--- a/clang/unittests/Sema/HeuristicResolverTest.cpp
+++ b/clang/unittests/Sema/HeuristicResolverTest.cpp
@@ -463,6 +463,23 @@ TEST(HeuristicResolver, DeclRefExpr_StaticMethod) {
       cxxMethodDecl(hasName("bar")).bind("output"));
 }
 
+TEST(HeuristicResolver, DeclRefExpr_DefaultTemplateArgument) {
+  std::string Code = R"cpp(
+    struct Default {
+      static void foo();
+    };
+    template <typename T = Default>
+    void bar() {
+      T::foo();
+    }
+  )cpp";
+  // Test resolution of "foo" in "T::foo()".
+  expectResolution(
+      Code, &HeuristicResolver::resolveDeclRefExpr,
+      dependentScopeDeclRefExpr(hasDependentName("foo")).bind("input"),
+      cxxMethodDecl(hasName("foo")).bind("output"));
+}
+
 TEST(HeuristicResolver, DeclRefExpr_StaticOverloads) {
   std::string Code = R"cpp(
     template <typename T>