From 177f5fe2255e2fd16040c802a7298ec21a29bd80 Mon Sep 17 00:00:00 2001 From: Luc Van Oostenryck Date: Thu, 9 Apr 2020 09:14:01 +0200 Subject: scope: give a scope for labels & gotos One way of detecting gotos inside an statement expression is to use a new kind of scope for the gotos & labels. Since gotos don't need to have their label predeclared, nothing can be checked at parsing time but later it can be checked that a goto doesn't jump inside one of the label scope created by statement expressions. So, add additional scope information to gotos and labels to allow such check to be done. Note: the label's symbols are still created in the function scope since they belong to a single namespace. Signed-off-by: Luc Van Oostenryck --- parse.c | 8 +++++++- parse.h | 1 + symbol.h | 4 ++++ 3 files changed, 12 insertions(+), 1 deletion(-) diff --git a/parse.c b/parse.c index ecc33765..bf45e3b0 100644 --- a/parse.c +++ b/parse.c @@ -2488,7 +2488,12 @@ static struct token *parse_goto_statement(struct token *token, struct statement token = parse_expression(token->next, &stmt->goto_expression); add_statement(&function_computed_goto_list, stmt); } else if (token_type(token) == TOKEN_IDENT) { - stmt->goto_label = label_symbol(token); + struct symbol *label = label_symbol(token); + stmt->goto_label = label; + if (!label->stmt && !label->label_scope) { + label->label_scope = label_scope; + label->label_pos = stmt->pos; + } token = token->next; } else { sparse_error(token->pos, "Expected identifier or goto expression"); @@ -2549,6 +2554,7 @@ static struct token *statement(struct token *token, struct statement **tree) } stmt->type = STMT_LABEL; stmt->label_identifier = s; + stmt->label_scope = label_scope; s->stmt = stmt; return statement(token, &stmt->label_statement); } diff --git a/parse.h b/parse.h index 0742a2a8..daef2439 100644 --- a/parse.h +++ b/parse.h @@ -72,6 +72,7 @@ struct statement { }; struct /* labeled_struct */ { struct symbol *label_identifier; + struct scope *label_scope; struct statement *label_statement; }; struct /* case_struct */ { diff --git a/symbol.h b/symbol.h index c297c778..2293d06d 100644 --- a/symbol.h +++ b/symbol.h @@ -167,6 +167,10 @@ struct symbol { int (*handler)(struct stream *, struct token **, struct token *); int normal; }; + struct /* NS_LABEL */ { + struct scope *label_scope; + struct position label_pos; + }; struct /* NS_SYMBOL */ { unsigned long offset; int bit_size; -- cgit 1.2.3-korg