From db0a795b145501e456cac5180be03ef697810845 Mon Sep 17 00:00:00 2001 From: Luc Van Oostenryck Date: Wed, 1 Apr 2020 15:45:33 +0200 Subject: scope: let labels have their own scope It's invalid to jump inside a statement expression. So, concerning labels & gotos, a statement expression is like a kind of scope. So, in preparation for the detection of such jumps, create these new scopes and open/close them when entering/leaving statement expressions. Signed-off-by: Luc Van Oostenryck --- expression.c | 2 ++ scope.c | 17 +++++++++++++++-- scope.h | 4 ++++ 3 files changed, 21 insertions(+), 2 deletions(-) diff --git a/expression.c b/expression.c index ffb3c2dc..f8a8f03e 100644 --- a/expression.c +++ b/expression.c @@ -71,7 +71,9 @@ struct token *parens_expression(struct token *token, struct expression **expr, c struct statement *stmt = alloc_statement(token->pos, STMT_COMPOUND); *expr = e; e->statement = stmt; + start_label_scope(); token = compound_statement(token->next, stmt); + end_label_scope(); token = expect(token, '}', "at end of statement expression"); } else token = parse_expression(token, expr); diff --git a/scope.c b/scope.c index cc54f1e1..75ee19cf 100644 --- a/scope.c +++ b/scope.c @@ -36,6 +36,7 @@ static struct scope builtin_scope = { .next = &builtin_scope }; struct scope *block_scope = &builtin_scope, // regular automatic variables etc + *label_scope = NULL, // expr-stmt labels *function_scope = &builtin_scope, // labels, arguments etc *file_scope = &builtin_scope, // static *global_scope = &builtin_scope; // externally visible @@ -91,8 +92,9 @@ void start_block_scope(void) void start_function_scope(void) { - start_scope(&function_scope); start_scope(&block_scope); + start_scope(&label_scope); + function_scope = label_scope; } static void remove_symbol_scope(struct symbol *sym) @@ -137,7 +139,18 @@ void end_block_scope(void) void end_function_scope(void) { end_scope(&block_scope); - end_scope(&function_scope); + end_label_scope(); + function_scope = label_scope; +} + +void start_label_scope(void) +{ + start_scope(&label_scope); +} + +void end_label_scope(void) +{ + end_scope(&label_scope); } int is_outer_scope(struct scope *scope) diff --git a/scope.h b/scope.h index 83741459..ddcb90bd 100644 --- a/scope.h +++ b/scope.h @@ -34,6 +34,7 @@ struct scope { extern struct scope *block_scope, + *label_scope, *function_scope, *file_scope, *global_scope; @@ -53,6 +54,9 @@ extern void end_block_scope(void); extern void start_function_scope(void); extern void end_function_scope(void); +extern void start_label_scope(void); +extern void end_label_scope(void); + extern void set_current_scope(struct symbol *); extern void bind_scope(struct symbol *, struct scope *); extern void rebind_scope(struct symbol *, struct scope *); -- cgit 1.2.3-korg