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Re: "cannot run C compiled programs" error
On Wed, Apr 27, 2011 at 7:01 AM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
> On 27 April 2011 06:11, Jeffrey Walton wrote:
>> On Tue, Apr 26, 2011 at 8:55 AM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
>>>
>>>>
>>>>> [SNIP]
>>>>>
>>>>> Please try to reproduce the error with a minimal example to show
>>>>> whether you get that error just from including a header, or only under
>>>>> certain circumstances.
>>>>
>>>> I managed to track it down to the following test.cpp file:
>>>>
>>>> #include <cmath>
>>>> #include <mgl/mgl.h>
>>>> #include <algorithm>
>>>>
>>>> Where mgl is from the wxWidgets library, version 2.8.11
>>>>
>>>> When I changed the order to:
>>>> #include <cmath>
>>>> #include <algorithm>
>>>> #include <mgl/mgl.h>
>>>>
>>>> It worked.
>>>
>>> That would imply the mgl.h header does something it shouldn't, such as
>>> defining isnan as a macro, or something else which breaks the standard
>>> library header.
>>>
>> I've also seen similar in the past. I seem to recall (like Anna) that
>> the C++ gear had to be included before [some of] the standard linux
>> stuff such as sys/types, sys/socket.h, and netinet/in.h. Fortunately,
>> the standard linux headers do a good job of guarding for multiple
>> definitions (when they follow C++ headers). The C++ headers, on the
>> other hand, do not always do a good job (when they follow standard
>> headers).
>
> Examples please. That would be a serious bug and should be reported to
> bugzilla rather than alluded to vaguely on a mailing list.
OK. When I encounter it again, I will let you know.
> mgl/mgl.h is not "standard linux stuff" so we can't do anything about
> that, but I'm pretty sure there are no conflicts between libstdc++
> headers and glibc headers (when used correctly)
OK. Perhaps I was doing something incorrectly.
Jeff