Re: Fw: Issue: headers may use non-reserved identifiers
C Howland <[email protected]>
| Newsgroups | gmane.comp.lib.newlib |
|---|---|
| Message-ID | <CANk6obSsuUUAyiv7d5bpOmEyF=qbaKUQp+xYpU_53QogRdnzSw@mail.gmail.com> |
> ------------------------------ > *From:* Newlib on behalf of Pavel M <[email protected]> > *Sent:* Wednesday, April 20, 2022 4:35 PM > *To:* [email protected] <[email protected]> > *Subject:* Issue: headers may use non-reserved identifiers > > > Hi all, > > Issue: headers may use non-reserved identifiers. > > Example: > #define _reent 0 > #include <stdio.h> > > $ gcc t567.c -std=c11 > t567.c:1:16: error: expected ‘{’ before numeric constant > 1 | #define _reent 0 > | ^ > t567.c:1:16: error: expected ‘{’ before numeric constant > 1 | #define _reent 0 > | ^ > and so on... > > Per C11 _reent, _on_exit_args, etc. are non-reserved identifiers. > > Consider fixing. > > P.S. Good if it leads to compile time errors, not good if it doesn't (wrong > translation unit produced => wrong code generated => wrong runtime > behavior). > > -- > Pavel > ------------------------------ > No, the headers do not use non-reserved identifiers. Look at the standard again, as the second dash item in section 7.1.3 Reserved Identifiers reserves all identifiers that start with underscore. The example program violates the standard. In short, user programs may not use identifiers that start with underscore. (More precisely there are some very-limited cases in which they can, but preprocessor identifiers is not one of them.)