Author: Nico Weber Date: 2024-06-07T14:08:42-04:00 New Revision: 2c047e67a5bfb479d7422f5b270e7f90ae037508
URL: https://github.com/llvm/llvm-project/commit/2c047e67a5bfb479d7422f5b270e7f90ae037508 DIFF: https://github.com/llvm/llvm-project/commit/2c047e67a5bfb479d7422f5b270e7f90ae037508.diff LOG: [clang] Add fixit for using declaration with a (qualified) namespace (#94762) For `using std::literals`, we now output: error: using declaration cannot refer to a namespace 4 | using std::literals; | ~~~~~^ note: did you mean 'using namespace'? 4 | using std::literals; | ^ | namespace Previously, we didn't have the note. This only fires for qualified namespaces. Just `using std;` doesn't trigger this, since using declarations without cxx scope specifier are rejected earlier. Making that work is an exercise for future selves :) Added: Modified: clang/include/clang/Basic/DiagnosticSemaKinds.td clang/lib/Sema/SemaDeclCXX.cpp clang/test/CXX/dcl.dcl/basic.namespace/namespace.udecl/p6-cxx11.cpp clang/test/CXX/drs/cwg4xx.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index ae78534ddec28..de3aa4b4028eb 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -607,6 +607,8 @@ def note_using_decl_class_member_workaround : Note< "a const variable|a constexpr variable}0 instead">; def err_using_decl_can_not_refer_to_namespace : Error< "using declaration cannot refer to a namespace">; +def note_namespace_using_decl : Note< + "did you mean 'using namespace'?">; def warn_cxx17_compat_using_decl_scoped_enumerator: Warning< "using declaration naming a scoped enumerator is incompatible with " "C++ standards before C++20">, InGroup<CXXPre20Compat>, DefaultIgnore; diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index 3c28da1b077cd..e224e79fdb8ea 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -13079,7 +13079,10 @@ NamedDecl *Sema::BuildUsingDeclaration( // A using-declaration shall not name a namespace. if (R.getAsSingle<NamespaceDecl>()) { Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace) - << SS.getRange(); + << SS.getRange(); + // Suggest using 'using namespace ...' instead. + Diag(SS.getBeginLoc(), diag::note_namespace_using_decl) + << FixItHint::CreateInsertion(SS.getBeginLoc(), "namespace "); return BuildInvalid(); } diff --git a/clang/test/CXX/dcl.dcl/basic.namespace/namespace.udecl/p6-cxx11.cpp b/clang/test/CXX/dcl.dcl/basic.namespace/namespace.udecl/p6-cxx11.cpp index 97b2953b90312..473290dd1c191 100644 --- a/clang/test/CXX/dcl.dcl/basic.namespace/namespace.udecl/p6-cxx11.cpp +++ b/clang/test/CXX/dcl.dcl/basic.namespace/namespace.udecl/p6-cxx11.cpp @@ -1,7 +1,10 @@ // RUN: %clang_cc1 -fsyntax-only -verify %s +// RUN: not %clang_cc1 -fsyntax-only -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s namespace A { namespace B { } } +// CHECK: fix-it:"{{.*}}":{[[@LINE+1]]:7-[[@LINE+1]]:7}:"namespace " using A::B; // expected-error{{using declaration cannot refer to a namespace}} + // expected-note@-1 {{did you mean 'using namespace'?}} diff --git a/clang/test/CXX/drs/cwg4xx.cpp b/clang/test/CXX/drs/cwg4xx.cpp index 6ada25237287c..98ff7553d989b 100644 --- a/clang/test/CXX/drs/cwg4xx.cpp +++ b/clang/test/CXX/drs/cwg4xx.cpp @@ -941,8 +941,10 @@ namespace cwg460 { // cwg460: yes // expected-error@-1 {{using declaration requires a qualified name}} using cwg460::X; // expected-error@-1 {{using declaration cannot refer to a namespace}} + // expected-note@-2 {{did you mean 'using namespace'?}} using X::Q; // expected-error@-1 {{using declaration cannot refer to a namespace}} + // expected-note@-2 {{did you mean 'using namespace'?}} } } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
