Issue 1002: Type qualifiers in [*] in abstract declarators

Authors: Joseph Myers
Date: 2025-03-06
Submitted against: C23
Status: Review
Cross-references: 0289

An array declarator can have the form (syntax in C23 6.7.7.1):

direct-declarator [ type-qualifier-list_opt * ]

but the corresponding abstract-declarator syntax in 6.7.8 omits the type-qualifier-list_opt. David Keaton stated in reflector message 14798 that this difference was not deliberate. The response to issue 0289 fixed such a difference in the case where an assignment expression is involved, but did nothing about the [*] case.

If abstract declarators have a more restrictive syntax than declarators, that confuses both the rules about replacing an expression at function prototype scope with *, and the rule that "If, in a parameter declaration, an identifier can be treated either as a typedef name or as a parameter name, it shall be taken as a typedef name.". It seems clear that the syntax should match in the two cases.

Suggested correction

In C23 6.7.8 (Type names), change the fourth option in the Syntax for array-abstract-declarator:

direct-abstract-declarator_opt [ type-qualifier-list_opt * ]

Comment from Issues list maintainer on 2025-09-01:

At the August 2025 (Brno) meeting of WG14, the suggested correction was accepted, subject to review at the next meeting.

Proposed correction

In C23 6.7.8 (Type names), change the fourth option in the Syntax for array-abstract-declarator:

direct-abstract-declarator_opt [ type-qualifier-list_opt * ]