JTC1/SC22/WG14
N692
Document Number: WG14 N692/J11 97-055
C9X Revision Proposal
=====================
Title: ____Implicit int cleanup_____________________________
Author: _____________Larry Jones____________________________
Author Affiliation: _SDRC___________________________________
Postal Address: _____2000 Eastman Dr, Milford, OH 45150_____
E-mail Address: _____larry.jones@sdrc.com___________________
Telephone Number: ___513-576-2070___________________________
Fax Number: _________513-576-2843___________________________
Sponsor: ____________Larry Jones____________________________
Date: _______________19 May 1997____________________________
Proposal Category:
X_ Editorial change/non-normative contribution
__ Correction
__ New feature
__ Addition to obsolescent feature list
__ Addition to Future Directions
__ Other (please specify)
Area of Standard Affected:
__ Environment
__ Language
__ Preprocessor
__ Library
__ Macro/typedef/tag name
__ Function
__ Header
__ Other (please specify) ______________________________
Prior Art: _________________________________________________
Target Audience: ___________________________________________
____________________________________________________________
____________________________________________________________
Related Documents (if any): N635, N636, N661________________
____________________________________________________________
____________________________________________________________
Proposal Attached: X_ Yes __ No, but what's your interest?
Abstract:
At previous meetings, the committee has voted to remove
various ``implicit int'' declarations from the language,
but some references to these implicit declarations remain
in the draft. This proposal corrects these oversights
and adds rationale. (Section and paragraph numbers
correspond to Draft 9.)
Proposal:
In subclause 6.7.1 Function definitions, Example 2,
remove the sentence ``Note that f must be declared
explicitly in the calling function, as its appearance in
the expression g(f) was not followed by (.''.
In subclause 7.1.7 Use of library functions, paragraph
[#2], first sentence, remove the text ``, either
explicitly or implicitly,'', and remove the second
sentence (``If a function that accepts a variable
number of arguments is not declared (explicitly or by
including its associated header), the behavior is
undefined.'').
In subclause I.2 Undefined behavior, remove the item:
-- A library function that accepts a variable
number of arguments is not declared (7.1.7).
In the Rationale, subclause 6.3.2.2 Function calls,
replace paragraph 4:
The rule for implicit declaration of functions
has been retained, but various past ambiguities
have been resolved by describing this usage in
terms of a corresponding explicit declaration.
with:
The rule for implicit declaration of functions
has been removed. The effect is to guarantee
that a diagnostic is produced, which will catch
an additional category of programming errors.
After issuing the diagnostic, an implementation
may choose to assume an implicit declaration and
continue translation in order to support existing
programs that exploited this feature.
In the Rationale, subclause 6.7.1 Function definitions,
add a new paragraph:
The rule which caused undeclared parameters in an
old-style function definition to be implicitly
declared int has been removed; undeclared
parameters are now a constraint violation. The
effect is to guarantee that a diagnostic is
produced, which will catch an additional
category of programming errors. After issuing
the diagnostic, an implementation may choose to
assume an implicit int declaration and continue
translation in order to support existing
programs that exploited this feature.