[clang] [libcxx] [Clang] Implement resolution for CWG1835 (PR #92957)

[Erich Keane via cfe-commits]

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@@ -1442,19 +1442,27 @@ SourceLocation CXXUnresolvedConstructExpr::getBeginLoc() const {
 CXXDependentScopeMemberExpr::CXXDependentScopeMemberExpr(
     const ASTContext &Ctx, Expr *Base, QualType BaseType, bool IsArrow,
     SourceLocation OperatorLoc, NestedNameSpecifierLoc QualifierLoc,
-    SourceLocation TemplateKWLoc, NamedDecl *FirstQualifierFoundInScope,
+    SourceLocation TemplateKWLoc, ArrayRef<DeclAccessPair> UnqualifiedLookups,
     DeclarationNameInfo MemberNameInfo,
     const TemplateArgumentListInfo *TemplateArgs)
     : Expr(CXXDependentScopeMemberExprClass, Ctx.DependentTy, VK_LValue,
            OK_Ordinary),
-      Base(Base), BaseType(BaseType), QualifierLoc(QualifierLoc),
-      MemberNameInfo(MemberNameInfo) {
+      Base(Base), BaseType(BaseType), MemberNameInfo(MemberNameInfo),
+      OperatorLoc(OperatorLoc) {
   CXXDependentScopeMemberExprBits.IsArrow = IsArrow;
+  CXXDependentScopeMemberExprBits.HasQualifier = QualifierLoc.hasQualifier();
+  CXXDependentScopeMemberExprBits.NumUnqualifiedLookups =
+      UnqualifiedLookups.size();
   CXXDependentScopeMemberExprBits.HasTemplateKWAndArgsInfo =
       (TemplateArgs != nullptr) || TemplateKWLoc.isValid();
-  CXXDependentScopeMemberExprBits.HasFirstQualifierFoundInScope =
-      FirstQualifierFoundInScope != nullptr;
-  CXXDependentScopeMemberExprBits.OperatorLoc = OperatorLoc;
+
+  if (hasQualifier())
+    new (getTrailingObjects<NestedNameSpecifierLoc>())
+        NestedNameSpecifierLoc(QualifierLoc);
+
+  std::uninitialized_copy_n(UnqualifiedLookups.data(),
+                            UnqualifiedLookups.size(),
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erichkeane wrote:

Any reason for `std::uninitialized_copy_n` vs `std::uninitialized_copy`?  Don't mind, mostly curious.

https://github.com/llvm/llvm-project/pull/92957