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Re: lint kills _Noreturn


On 5/29/2016 3:09 PM, Andy Moreton wrote:
On Sun 29 May 2016, Ken Brown wrote:

On 5/29/2016 12:56 PM, Andy Moreton wrote:
On Sun 29 May 2016, Ken Brown wrote:

If lint is defined, then /usr/include/sys/cdefs.h defines _Noreturn as a macro
that expands to nothing.  Is this intentional?

Simple test case:

$ cat test.h
#define lint 1
#include <sys/cdefs.h>
_Noreturn void foo (void);

$ gcc -E test.h | grep foo
         void foo (void);


Ken

A traditional lint program may not support the new C11 keywords, but
will define the 'lint' symbol. See, e.g.
     http://www.unix.com/man-page/FreeBSD/1/lint

But in the present context (see my second message), we're redefining C11
keywords even though __STDC_VERSION__ >= 201112L.

Agreed, but that should only affect a lint program that understands C11.
Any other program should simply not be defining lint in the first place.

Surely the real problem here is a program which is not a lint executable
defining 'lint' ?

The program is emacs built from a git checkout of the master branch.  By
default the configure option --enable-gcc-checking is used, and this causes
lint to be defined in src/config.h.  It doesn't seem to be a problem on
platforms other than Cygwin; or at least it hasn't been reported.

I saw your report of emacs bug#23640, and followed here. I think the
real question is why the recent change to emacs configure.ac added a
definition of lint - that seems wrong.

That was actually added about 4 years ago, in commit b8df54f, when the --enable-gcc-warnings option was first added. The only thing that changed recently was that the warnings are enabled by default on a git checkout of master.

Ken

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