From 892c3d996f77c7874d4b2ee9f27812bca1903839 Mon Sep 17 00:00:00 2001 From: Michael Matz Date: Sun, 4 Sep 2016 05:21:19 +0200 Subject: [PATCH] Reject jumping inside stmtexprs One can't jump into statement expressions from outside them, like the following: int i = ({ label: foo(); 42; }); goto label; We reject this by making the labels simply not available outside (GCC has a nicer error message about jumping into a statement expression). --- tccgen.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/tccgen.c b/tccgen.c index 53ce1858..02e56eb9 100644 --- a/tccgen.c +++ b/tccgen.c @@ -5406,7 +5406,7 @@ static void block(int *bsym, int *csym, int is_expr) gsym(a); gsym_addr(b, d); } else if (tok == '{') { - Sym *llabel; + Sym *llabel, *glabel; int block_vla_sp_loc = vla_sp_loc, saved_vlas_in_scope = vlas_in_scope; next(); @@ -5414,6 +5414,10 @@ static void block(int *bsym, int *csym, int is_expr) s = local_stack; llabel = local_label_stack; ++local_scope; + /* Labels defined inside statement expressions aren't + available from the outside, so record that as well. */ + if (is_expr) + glabel = global_label_stack; /* handle local labels declarations */ if (tok == TOK_LABEL) { @@ -5439,6 +5443,8 @@ static void block(int *bsym, int *csym, int is_expr) block(bsym, csym, is_expr); } } + if (is_expr) + label_pop(&global_label_stack, glabel); /* pop locally defined labels */ label_pop(&local_label_stack, llabel); /* pop locally defined symbols */