https://wg21.link/P2324 void foo(void) { first: // #1 allowed in C++, now also allowed in C int x; second: // #2 allowed in both C++ and C x = 1; last: // #3 not allowed in C++, but now allowed in C } This proposal makes #3 OK.
The trunk branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>: https://gcc.gnu.org/g:4b2a6628644b2ce15d877c1e85d14e314965a296 commit r13-217-g4b2a6628644b2ce15d877c1e85d14e314965a296 Author: Marek Polacek <polacek@redhat.com> Date: Sun May 8 17:36:34 2022 -0400 c++: Implement P2324R2, labels at the end of compound-stmts [PR103539] This patch implements C++23 <https://wg21.link/p2324r2>, which allows labels at the end of a compound statement. Its C FE counterpart was already implemented in r11-4813. In cp_parser_statement I rely on in_compound to determine whether we're in a compound-statement, so that the patch doesn't accidentally allow void fn(int c) { if (c) label: } Strangely, in_compound was reset after seeing a label (this is tested in c-c++-common/gomp/pr63326.c), so I've made a modifiable copy specific for OpenMP #pragma purposes. PR c++/103539 gcc/cp/ChangeLog: * parser.cc (cp_parser_statement): Constify the in_compound parameter. Create a modifiable copy. Allow labels at the end of compound statements. gcc/testsuite/ChangeLog: * g++.dg/cpp23/label1.C: New test. * g++.dg/cpp23/label2.C: New test.
Implemented in GCC 13.