On Tue, Apr 14, 2020 at 12:49 AM Luc Van Oostenryck
<luc.vanoostenryck@xxxxxxxxx> wrote:
>
> The problem is that now normal labels use the new label_scope
> but the ones declared with __label__ use block_scope and these
> 2 scopes are kinda in a different namespace of scope.
Oh, I forgot about the special __label__ thing that actually declares labels.
That one has an interesting behavior, in that the _lifetime_ of the
symbol is the block scope, but the *use* of the symbol must remain in
label scope.
The most obvious fix is probably something like the appended: make the
'sym->scope' remain the lifetime scope, but then attach a "must be
used in this scope' thing to any NS_LABEL case.
That fairly clearly separates the two issues.
Again, not actually tested outside of the obvious trivial case.
Linus
parse.c | 16 +++++++++++-----
scope.c | 1 +
symbol.h | 3 +++
3 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/parse.c b/parse.c
index 8e238f59..b6109516 100644
--- a/parse.c
+++ b/parse.c
@@ -728,6 +728,7 @@ struct symbol *label_symbol(struct token *token)
if (!sym) {
sym = alloc_symbol(token->pos, SYM_LABEL);
bind_symbol(sym, token->ident, NS_LABEL);
+ sym->declared_scope = label_scope;
fn_local_symbol(sym);
}
return sym;
@@ -2541,13 +2542,14 @@ static struct token *statement(struct token *token, struct statement **tree)
}
/*
* If the scope of the label symbol is different
- * from the current label scope, that means that
- * it must have been used at an outer scope.
+ * from the declared label scope, that means that
+ * it must have been used or declared at an outer
+ * scope.
*
* That's not ok.
*/
- if (s->scope != label_scope) {
- sparse_error(stmt->pos, "label '%s' used outside label expression", show_ident(s->ident));
+ if (s->scope != s->declared_scope) {
+ sparse_error(stmt->pos, "label '%s' used outside statement expression", show_ident(s->ident));
sparse_error(s->pos, "invalid use here");
}
stmt->type = STMT_LABEL;
@@ -2575,9 +2577,13 @@ static struct token *label_statement(struct token *token)
{
while (token_type(token) == TOKEN_IDENT) {
struct symbol *sym = alloc_symbol(token->pos, SYM_LABEL);
- /* it's block-scope, but we want label namespace */
+
+ /* it's lifetile is block-scope, but we want label namespace */
bind_symbol(sym, token->ident, NS_SYMBOL);
sym->namespace = NS_LABEL;
+
+ /* But we must define it in this label scope */
+ sym->declared_scope = label_scope;
fn_local_symbol(sym);
token = token->next;
if (!match_op(token, ','))
diff --git a/scope.c b/scope.c
index 4b0f7947..11792ec4 100644
--- a/scope.c
+++ b/scope.c
@@ -171,6 +171,7 @@ void end_label_scope(void)
/* Re-bind the symbol to the parent scope, we'll try again */
bind_scope(sym, label_scope);
+ sym->declared_scope = label_scope;
} END_FOR_EACH_PTR(sym);
end_scope(&block_scope);
diff --git a/symbol.h b/symbol.h
index 18476582..08e35438 100644
--- a/symbol.h
+++ b/symbol.h
@@ -167,6 +167,9 @@ struct symbol {
int (*handler)(struct stream *, struct token **, struct token *);
int normal;
};
+ struct /* NS_LABEL */ {
+ struct scope *declared_scope;
+ };
struct /* NS_SYMBOL */ {
unsigned long offset;
int bit_size;
