WG 14 Standing Document 3
List of issues not covered by DRs for C11
|Doc No:||WG 14 N 1917|
|Reply To:||David Keaton|
|Convener, WG 14
848 N. Rainbow Blvd. #4499
Las Vegas, NV 89107
|Phone:||+1 702 518 8192|
|Fax:||+1 702 852 0248|
This document contains a list of issues that could not be dealt with by a C11 Defect Report. Each should be reviewed when the time comes to start the process to republish the C Standard.
This document is not intended to indicate the direction WG 14 will take for the development of the C Standard, this is just a list of issues that were not addressed by the WG 14 Defect Report process.
To do as suggested in this defect report, distinguish whether the
long doubletypes are IEC compliant or not, requires the addition of new feature test macros. This is a new feature, and is not allowed by the mechanism of the defect report process.
This is a request to align C with C++14, C++14 has defined the shifting of a bit into the sign bit, again this is a feature that can not be addressed by the defect report process. The following change was proposed in the defect report.6.5.7p4 should be modified to read:The result of
E1 << E2is
E2bit positions; vacated bits are filled with zeros. If
E1has an unsigned type, the value of the result is
E1 x 2E2, reduced modulo one more than the maximum value representable in the result type. If
E1has a signed type and nonnegative value, and
E1 x 2E2is representable in the result type, then that is the resulting value; otherwise, the behavior is undefined.
The issue about indeterminate values (wobbly bits) will possibly need to be clarified. Wobbly bits were not considered during the development of C11.
The portion of this defect report that requests allowing
constqualified objects in signal handlers is considered a new feature. The implications of the following suggested change from the defect report should be studied carefully before adopting any change.
In section 22.214.171.124, modify the first sentence of paragraph 5 as indicated below:If the signal occurs other than as the result of calling the abort or raise function, the behavior is undefined if the signal handler
refers toany object with static or thread storage duration that is not a lock-free atomic object other than by...
In addition, make the corresponding change to section J.2 Undefined behavior.
This defect report requests a local change to a globally-used term. A comprehensive review of all uses would be required, which is outside the scope of this defect report.
This defect report requests a harmonization with C++, which is often grounds for making a change. However, this particular change would invalidate existing code and should not be done using the defect report process. The following change was proposed in the defect report.
Align the C rules with those of C++ by adding a new paragraph to section 6.2.1 Scopes of identifiers as follows.