Defect Report #055
Submission Date: 14 Apr 93
Submittor: Project Editor (P.J. Plauger)
Source: Loren Schall
Question 1
It has been suggested that the six macros SIGABRT, SIGFPE,
SIGILL, SIGINT, SIGSEGV, and SIGTERM must
have distinct values. Here is the relevant portion of subclause 7.7:
``The macros defined are
SIG_DFL
SIG_ERR
SIG_IGN
which expand to constant expressions with distinct values that have
type compatible with the second argument to and the return value of
the signal function, and whose value compares unequal to the
address of any declarable function; and the following, each of which
expands to a positive integral constant expression that is the signal
number corresponding to the specified condition:
...
An implementation need not generate any of these signals, except as
a result of explicit calls to the raise function.''
On the one hand, the reference to ``the signal number corresponding
to the specified condition'' might be assumed to imply different
numbers for each signal. On the other hand, the words ``distinct
values'' were explicitly used for the three SIG_* macros
and are conspicuously missing for the others.
Also, I think it's worth noting that the standard expects raise
to work meaningfully (i.e. to be able to tell them apart).
Summary: must SIGABRT, SIGFPE, SIGILL, SIGINT,
SIGSEGV, and SIGTERM have distinct values?
Correction
In subclause 7.7, page 120, lines 14-16, change:
and the following, each of which expands to a positive integral constant
expression that is the signal number corresponding to the specified
condition:
to:
and the following, which expand to positive integral constant expressions
with distinct values that are the signal numbers, each corresponding
to the specified condition:
Previous Defect Report
< - >
Next Defect Report