Hi! The C FE in multiple spots checks building_stmt_list_p () to decide if we are inside of parsing of functions or outside of that.
Unfortunately, that breaks with add_debug_begin_stmt which pushes DEBUG_BEGIN_STMTs regardless of the scope it appears in; e.g. on the testcase below it pushes DEBUG_BEGIN_STMT already for the int a declaration in column 1 on line 5, and so with -g building_stmt_list_p () is pretty much always true. Fixed by only pushing DEBUG_BEGIN_STMTs when the building_stmt_list_p () predicate is true, they aren't really useful outside of functions anyway. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2018-03-06 Jakub Jelinek <ja...@redhat.com> PR c/84721 * c-parser.c (add_debug_begin_stmt): Don't add DEBUG_BEGIN_STMT if !building_stmt_list_p (). * gcc.dg/pr84721.c: New test. --- gcc/c/c-parser.c.jj 2018-02-06 13:12:49.320804579 +0100 +++ gcc/c/c-parser.c 2018-03-06 10:56:54.207194189 +0100 @@ -1654,7 +1654,8 @@ static void c_finish_oacc_routine (struc static void add_debug_begin_stmt (location_t loc) { - if (!MAY_HAVE_DEBUG_MARKER_STMTS) + /* Don't add DEBUG_BEGIN_STMTs outside of functions, see PR84721. */ + if (!MAY_HAVE_DEBUG_MARKER_STMTS || !building_stmt_list_p ()) return; tree stmt = build0 (DEBUG_BEGIN_STMT, void_type_node); --- gcc/testsuite/gcc.dg/pr84721.c.jj 2018-03-06 11:03:23.798005268 +0100 +++ gcc/testsuite/gcc.dg/pr84721.c 2018-03-06 11:02:59.741016937 +0100 @@ -0,0 +1,6 @@ +/* PR c/84721 */ +/* { dg-do compile } */ +/* { dg-options "-g -O2" } */ + +int a[({ int b })]; /* { dg-error "braced-group within expression allowed only inside a function" } */ +int c[({ int d () {}; })]; /* { dg-error "braced-group within expression allowed only inside a function" } */ Jakub