diff options
Diffstat (limited to 'gcc/cp/semantics.c')
| -rw-r--r-- | gcc/cp/semantics.c | 180 |
1 files changed, 95 insertions, 85 deletions
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c index 3ca91d8..ab8c82a 100644 --- a/gcc/cp/semantics.c +++ b/gcc/cp/semantics.c @@ -3067,13 +3067,105 @@ outer_var_p (tree decl) /* As above, but also checks that DECL is automatic. */ -static bool +bool outer_automatic_var_p (tree decl) { return (outer_var_p (decl) && !TREE_STATIC (decl)); } +/* DECL satisfies outer_automatic_var_p. Possibly complain about it or + rewrite it for lambda capture. */ + +tree +process_outer_var_ref (tree decl, tsubst_flags_t complain) +{ + if (cp_unevaluated_operand) + /* It's not a use (3.2) if we're in an unevaluated context. */ + return decl; + + tree context = DECL_CONTEXT (decl); + tree containing_function = current_function_decl; + tree lambda_stack = NULL_TREE; + tree lambda_expr = NULL_TREE; + tree initializer = convert_from_reference (decl); + + /* Mark it as used now even if the use is ill-formed. */ + mark_used (decl); + + /* Core issue 696: "[At the July 2009 meeting] the CWG expressed + support for an approach in which a reference to a local + [constant] automatic variable in a nested class or lambda body + would enter the expression as an rvalue, which would reduce + the complexity of the problem" + + FIXME update for final resolution of core issue 696. */ + if (decl_maybe_constant_var_p (decl)) + { + if (processing_template_decl) + /* In a template, the constant value may not be in a usable + form, so wait until instantiation time. */ + return decl; + else if (decl_constant_var_p (decl)) + return integral_constant_value (decl); + } + + if (parsing_nsdmi ()) + containing_function = NULL_TREE; + else + /* If we are in a lambda function, we can move out until we hit + 1. the context, + 2. a non-lambda function, or + 3. a non-default capturing lambda function. */ + while (context != containing_function + && LAMBDA_FUNCTION_P (containing_function)) + { + lambda_expr = CLASSTYPE_LAMBDA_EXPR + (DECL_CONTEXT (containing_function)); + + if (LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (lambda_expr) + == CPLD_NONE) + break; + + lambda_stack = tree_cons (NULL_TREE, + lambda_expr, + lambda_stack); + + containing_function + = decl_function_context (containing_function); + } + + if (lambda_expr && TREE_CODE (decl) == VAR_DECL + && DECL_ANON_UNION_VAR_P (decl)) + { + if (complain & tf_error) + error ("cannot capture member %qD of anonymous union", decl); + return error_mark_node; + } + if (context == containing_function) + { + decl = add_default_capture (lambda_stack, + /*id=*/DECL_NAME (decl), + initializer); + } + else if (lambda_expr) + { + if (complain & tf_error) + error ("%qD is not captured", decl); + return error_mark_node; + } + else + { + if (complain & tf_error) + error (VAR_P (decl) + ? G_("use of local variable with automatic storage from containing function") + : G_("use of parameter from containing function")); + inform (input_location, "%q+#D declared here", decl); + return error_mark_node; + } + return decl; +} + /* ID_EXPRESSION is a representation of parsed, but unprocessed, id-expression. (See cp_parser_id_expression for details.) SCOPE, if non-NULL, is the type or namespace used to explicitly qualify @@ -3179,90 +3271,8 @@ finish_id_expression (tree id_expression, /* Disallow uses of local variables from containing functions, except within lambda-expressions. */ - if (!outer_var_p (decl)) - /* OK */; - else if (TREE_STATIC (decl) - /* It's not a use (3.2) if we're in an unevaluated context. */ - || cp_unevaluated_operand) - /* OK */; - else - { - tree context = DECL_CONTEXT (decl); - tree containing_function = current_function_decl; - tree lambda_stack = NULL_TREE; - tree lambda_expr = NULL_TREE; - tree initializer = convert_from_reference (decl); - - /* Mark it as used now even if the use is ill-formed. */ - mark_used (decl); - - /* Core issue 696: "[At the July 2009 meeting] the CWG expressed - support for an approach in which a reference to a local - [constant] automatic variable in a nested class or lambda body - would enter the expression as an rvalue, which would reduce - the complexity of the problem" - - FIXME update for final resolution of core issue 696. */ - if (decl_maybe_constant_var_p (decl)) - { - if (processing_template_decl) - /* In a template, the constant value may not be in a usable - form, so wait until instantiation time. */ - return decl; - else if (decl_constant_var_p (decl)) - return integral_constant_value (decl); - } - - if (parsing_nsdmi ()) - containing_function = NULL_TREE; - /* If we are in a lambda function, we can move out until we hit - 1. the context, - 2. a non-lambda function, or - 3. a non-default capturing lambda function. */ - else while (context != containing_function - && LAMBDA_FUNCTION_P (containing_function)) - { - lambda_expr = CLASSTYPE_LAMBDA_EXPR - (DECL_CONTEXT (containing_function)); - - if (LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (lambda_expr) - == CPLD_NONE) - break; - - lambda_stack = tree_cons (NULL_TREE, - lambda_expr, - lambda_stack); - - containing_function - = decl_function_context (containing_function); - } - - if (lambda_expr && TREE_CODE (decl) == VAR_DECL - && DECL_ANON_UNION_VAR_P (decl)) - { - error ("cannot capture member %qD of anonymous union", decl); - return error_mark_node; - } - if (context == containing_function) - { - decl = add_default_capture (lambda_stack, - /*id=*/DECL_NAME (decl), - initializer); - } - else if (lambda_expr) - { - error ("%qD is not captured", decl); - return error_mark_node; - } - else - { - error (VAR_P (decl) - ? G_("use of local variable with automatic storage from containing function") - : G_("use of parameter from containing function")); - inform (input_location, "%q+#D declared here", decl); - return error_mark_node; - } - } + if (outer_automatic_var_p (decl)) + decl = process_outer_var_ref (decl, tf_warning_or_error); /* Also disallow uses of function parameters outside the function body, except inside an unevaluated context (i.e. decltype). */ |