Re: [PATCH] gdb: fix -Wdeprecated-declarations on macOS

[Simon Marchi <simark@simark.ca>]

On 3/28/23 10:16, Enze Li via Gdb-patches wrote:
> I noticed that there are some issues when compiling on macOS.  There are
> a few places where errors like the following are reported,
> 
> ======
>   CXX    cli/cli-cmds.o
> cli/cli-cmds.c:929:14: error: 'vfork' is deprecated: Use posix_spawn or fork [-Werror,-Wdeprecated-declarations]
>   if ((pid = vfork ()) == 0)
>              ^
> /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/unistd.h:604:1: note: 'vfork' has been explicitly marked deprecated here
> __deprecated_msg("Use posix_spawn or fork")
> ^
> /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/cdefs.h:208:48: note: expanded from macro '__deprecated_msg'
>         #define __deprecated_msg(_msg) __attribute__((__deprecated__(_msg)))
>                                                       ^
> 1 error generated.
> ======
> 
> This patch is only available for the macOS platform.  This is done by
> using macros to differentiate between specific platforms.
> 
> Tested by rebuilding both on x86_64 linux and macOS Big Sur.

Any idea why vfork is deprecated on macOS?  I can't find any answer
online.

I think it would be good to have a gdb_ util function with the ifdef at
a single place, with an appropriate comment.  I don't know how to call
this function though.  Would calling it gdb_vfork be misleading, because
it won't always vfork?

Simon