Using Macports' gcc8 to build C programs and libraries

[Chris Jones]

Hi,

My macOD 10.13 box I have access to right now has

/usr/include/sys/cdefs.h

which should be found by default.

I suspect this is a case of the OP's macOS10.14 does not have the 
command line tools package installed (as this is depreciated in 10.14) 
and thus does not have this header installed.

If so, then I go back to my last post. The best fix here is to use clang 
instead of gcc.

cheers Chris


On 01/04/2019 10:18 am, Andrew Udvare wrote:
> 
> 
>> On 2019-04-01, at 05:10, Sean Lake <odysseus9672 at gmail.com> wrote:
>>
>> In file included from MWReddening.c:1:
>> /opt/local/lib/gcc8/gcc/x86_64-apple-darwin18/8.3.0/include-fixed/math.h:45:10:fatal
>> error: sys/cdefs.h: No such file or directory
>> #include <sys/cdefs.h>
>>           ^~~~~~~~~~~~~
> 
> You should have this file at:
> 
> /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/cdefs.h
> 
> Assuming GCC 8 can use Apple's headers, add:
> 
> -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include
> 
>>
>> Looking for similar errors on the web, I get pages like this
>>
>> https://stackoverflow.com/questions/31045721/c-compiler-error-cdefs-h-not-found
>>
>> that recommend installing a libc package. Will a similar solution work
>> in Macports? If so, which package(s)? If not, will modifying my CFLAGS
>> and LDFLAGS suffice? Currently, I have included "-I/opt/local/include"
>> in CFLAGS and "-L/opt/local/lib" in LDFLAGS, but that's obviously not
>> enough (or wrong).
> 
> 
> There are some (dated) libc* packages. Run `port search 'Library for cross-platform C'`.
>