[clangd] Do not ignore qualifier in heuristic resolution of dependent MemberExpr

Fixes #64841

Differential Revision: https://reviews.llvm.org/D158873

Author: HighCommander4

clang-tools-extra/clangd/HeuristicResolver.cpp

@@ -119,8 +119,8 @@ const Type *HeuristicResolver::getPointeeType(const Type *T) const {
 
 std::vector<const NamedDecl *> HeuristicResolver::resolveMemberExpr(
     const CXXDependentScopeMemberExpr *ME) const {
-  // If the expression has a qualifier, first try resolving the member
-  // inside the qualifier's type.
+  // If the expression has a qualifier, try resolving the member inside the
+  // qualifier's type.
   // Note that we cannot use a NonStaticFilter in either case, for a couple
   // of reasons:
   //   1. It's valid to access a static member using instance member syntax,
@@ -137,10 +137,15 @@ std::vector<const NamedDecl *> HeuristicResolver::resolveMemberExpr(
       if (!Decls.empty())
         return Decls;
     }
+
+    // Do not proceed to try resolving the member in the expression's base type
+    // without regard to the qualifier, as that could produce incorrect results.
+    // For example, `void foo() { this->Base::foo(); }` shouldn't resolve to
+    // foo() itself!
+    return {};
   }
 
-  // If that didn't yield any results, try resolving the member inside
-  // the expression's base type.
+  // Try resolving the member inside the expression's base type.
   const Type *BaseType = ME->getBaseType().getTypePtrOrNull();
   if (ME->isArrow()) {
     BaseType = getPointeeType(BaseType);

clang-tools-extra/clangd/unittests/XRefsTests.cpp

@@ -1009,7 +1009,17 @@ TEST(LocateSymbol, All) {
         void play(Dog *dog) {
           [dog ho^wl];
         }
-      )objc"};
+      )objc",
+      R"cpp(
+        struct PointerIntPairInfo {
+          static void *getPointer(void *Value);
+        };
+
+        template <typename Info = PointerIntPairInfo> struct PointerIntPair {
+          void *Value;
+          void *getPointer() const { return Info::get^Pointer(Value); }
+        };
+    )cpp"};
   for (const char *Test : Tests) {
     Annotations T(Test);
     std::optional<Range> WantDecl;