Build errors on MacOS Big Sur

[Zaid Al-Jarrah]

Hello Jose,

I’m trying to add GNU Recutils to MacPorts and I’m running into a small issue in getting it compiled on macOS Big Sur (11.5) due to a few -Wimplicit-function-declaration] warnings which are being treated like errors on newer MacOS versions.

The PR with the proposed changes is at https://github.com/macports/macports-ports/pull/12165 and the log showing the errors is at https://gist.github.com/zaid/1e2010700b9b03b3e48a4b794524997d 

For example, we see the following in the log file:

:info:build rec-sex-parser.c:67:7: error: implicit declaration of function 'sexlex_init' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
:info:build       sexlex_init (&(new->scanner));
:info:build       ^
:info:build rec-sex-parser.c:68:7: error: implicit declaration of function 'sexset_extra' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
:info:build       sexset_extra (new, new->scanner);
:info:build       ^
:info:build /bin/sh ../libtool  --tag=CC   --mode=compile /usr/bin/clang -DHAVE_CONFIG_H -I.  -I../lib -I../lib -DLOCALEDIR=\"/opt/local/share/locale\" -DREMOTE_DESCRIPTORS -DUUID_TYPE -I/opt/local/include -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX11.sdk  -pipe -Os -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX11.sdk -arch x86_64 -c -o rec-sex-tab.lo rec-sex-tab.c
:info:build rec-sex-parser.c:85:7: error: implicit declaration of function 'sexlex_destroy' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
:info:build       sexlex_destroy (parser->scanner);
:info:build       ^
:info:build 3 errors generated.

The code builds (despite the warnings) on older version of MacOS (10.13) but it looks like newer versions are treating warnings as errors and failing the build.

Any advice on how to fix these?

Thanks,

Zaid