Public Comment Number PC-UK0165

ISO/IEC CD 9899 (SC22N2620) Public Comment

=========================================== 

Date: 1998-02-25
Author: N.M Maclaren
Author Affiliation: Self
Postal Address:
    University of Cambridge,
    Computer Laboratory,
    New Museums Site,
    Pembroke Street,
    Cambridge CB3 3QG,
    United Kingdom
E-mail Address: <nmm1@cam.ac.uk>
Telephone Number: +44 1223 334761
Fax Number:       +44 1223 334679
Number of individual comments: 1


Comment 1. 

Category: Editorial change/non-normative contribution

Committee Draft subsection: H.3.1, H.3.1.2

Title: Incorrect claims of LIA-1 conformance


Detailed description:

LIA-1 6.1.1 point (c) requires the ability to permit the programmer to
specify code to compensate for exceptions if this form of exception
handling is used.  C does not permit such code, but H.3.1 paragraph 4
claims that it does.  In particular, there is no way to return a corrected
value after a numeric (SIGFPE) signal.  This statement should be corrected.

H.3.1.2 paragraph 4 claims that the C standard allows trap-and-terminate as
well as trap-and-resume.  Both of these are undefined behaviour (7.11.1.1
The signal function, paragraphs 3 and 5).  While undefined behaviour is not
incompatible with LIA-1 (obviously), it is seriously misleading to use it
to claim that the C standard supports LIA-1 (see H.1 Introduction).  This
statement should be corrected.