Informix Error -4046: Formal declaration appeared previously for this informal function definition. The formal declaration is invalidated.

Reasons / Common Causes

-4046 fires when a function already has a formal (prototype-style) declaration earlier in the module, but its actual definition then uses informal function syntax — per the official guidance, this invalidates the earlier formal declaration.

1. A function with an earlier formal (prototype) declaration whose definition uses informal syntax, per the official guidance — the direct, only cause.

Solutions / Resolution

1. Make the function's declaration and definition consistently use either formal or informal syntax.

Examples

A formal declaration followed by an informal definition

FUNCTION save(id INTEGER) RETURNING INTEGER

FUNCTION save(id)
  -- -4046: this informal definition invalidates the formal declaration above
END FUNCTION

Corrected

FUNCTION save(id INTEGER) RETURNING INTEGER
  ...
END FUNCTION

Diagnostic Checks

1. Check every function with an earlier formal declaration, and confirm its definition also uses formal syntax.

Related Errors / Related Topics

• -4050 — "Function "name" has been used and hence declared as informal before this formal declaration." A related formal/informal declaration-ordering error, about a call preceding a formal declaration rather than a formal declaration being invalidated by an informal definition.

A function's formal declaration is invalidated by an informal-syntax definition — make both consistent.