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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).
master
Michael Matz 2016-09-04 05:21:19 +02:00
parent 1602998751
commit 892c3d996f
1 changed files with 7 additions and 1 deletions
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8
tccgen.c
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@ -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 */