Hi! This patch let us warn about danling else even if there is a switch without {}s around the body.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2016-05-04 Jakub Jelinek <ja...@redhat.com> * c-parser.c (c_parser_switch_statement): Add IF_P argument, parse it through to c_parser_c99_block_statement. (c_parser_statement_after_labels): Adjust c_parser_switch_statement caller. * parser.c (cp_parser_selection_statement): For RID_SWITCH, pass if_p instead of NULL to cp_parser_implicitly_scoped_statement. * c-c++-common/Wdangling-else-4.c: New test. --- gcc/c/c-parser.c.jj 2016-05-03 00:12:10.000000000 +0200 +++ gcc/c/c-parser.c 2016-05-04 18:09:27.384953312 +0200 @@ -1305,7 +1305,7 @@ static void c_parser_statement (c_parser static void c_parser_statement_after_labels (c_parser *, bool *, vec<tree> * = NULL); static void c_parser_if_statement (c_parser *, bool *, vec<tree> *); -static void c_parser_switch_statement (c_parser *); +static void c_parser_switch_statement (c_parser *, bool *); static void c_parser_while_statement (c_parser *, bool, bool *); static void c_parser_do_statement (c_parser *, bool); static void c_parser_for_statement (c_parser *, bool, bool *); @@ -5138,7 +5138,7 @@ c_parser_statement_after_labels (c_parse c_parser_if_statement (parser, if_p, chain); break; case RID_SWITCH: - c_parser_switch_statement (parser); + c_parser_switch_statement (parser, if_p); break; case RID_WHILE: c_parser_while_statement (parser, false, if_p); @@ -5570,7 +5570,7 @@ c_parser_if_statement (c_parser *parser, */ static void -c_parser_switch_statement (c_parser *parser) +c_parser_switch_statement (c_parser *parser, bool *if_p) { struct c_expr ce; tree block, expr, body, save_break; @@ -5605,7 +5605,7 @@ c_parser_switch_statement (c_parser *par c_start_case (switch_loc, switch_cond_loc, expr, explicit_cast_p); save_break = c_break_label; c_break_label = NULL_TREE; - body = c_parser_c99_block_statement (parser, NULL/*if??*/); + body = c_parser_c99_block_statement (parser, if_p); c_finish_case (body, ce.original_type); if (c_break_label) { --- gcc/cp/parser.c.jj 2016-05-03 00:12:11.000000000 +0200 +++ gcc/cp/parser.c 2016-05-04 18:15:30.614109144 +0200 @@ -10978,7 +10978,7 @@ cp_parser_selection_statement (cp_parser in_statement = parser->in_statement; parser->in_switch_statement_p = true; parser->in_statement |= IN_SWITCH_STMT; - cp_parser_implicitly_scoped_statement (parser, NULL, + cp_parser_implicitly_scoped_statement (parser, if_p, guard_tinfo); parser->in_switch_statement_p = in_switch_statement_p; parser->in_statement = in_statement; --- gcc/testsuite/c-c++-common/Wdangling-else-4.c.jj 2016-05-04 18:40:17.628299460 +0200 +++ gcc/testsuite/c-c++-common/Wdangling-else-4.c 2016-05-04 18:36:19.000000000 +0200 @@ -0,0 +1,31 @@ +/* { dg-do compile } */ +/* { dg-options "-Wdangling-else" } */ + +void bar (int); + +void +foo (int a, int b, int c) +{ + if (a) /* { dg-warning "suggest explicit braces to avoid ambiguous .else." } */ + switch (b) + case 0: + if (c) + bar (1); + else + bar (2); +} + +void +baz (int a, int b, int c) +{ + if (a) + switch (b) + { + case 0: + if (c) + bar (1); + } + else + bar (2); +} + Jakub