Re: sys_random: Work around macOS bug

[Jeffrey Walton]

On Sat, May 30, 2020 at 7:06 PM Bruno Haible <bruno@clisp.org> wrote:
>
> On Mac OS X, the header file <sys/random.h> is not self-contained.
>
> On Mac OS X 10.5:
>
>   In file included from ./sys/random.h:28,
>                    from ../../gllib/getrandom.c:22:
>   /usr/include/sys/random.h:37: error: syntax error before ‘u_int’
>
> It needs <sys/types.h> to be included first.
>
> On Mac OS X 10.13:
>
>   In file included from ../../gllib/getrandom.c:22:
>   In file included from ./sys/random.h:28:
>   /usr/include/sys/random.h:36:17: error: expected parameter declarator
>   __OSX_AVAILABLE(10.12) __IOS_AVAILABLE(10.0) __TVOS_AVAILABLE(10.0) 
> __WATCHOS_AVAILABLE(3.0)
>                   ^
>
> It needs <stdlib.h> or <unistd.h> to be included first.
>
> This patch provides a workaround.
>
>
> 2020-05-30  Bruno Haible  <bruno@clisp.org>
>
>         sys_random: Work around macOS bug.
>         * m4/sys_random_h.m4 (gl_HEADER_SYS_RANDOM): Include <sys/types.h> and
>         <stdlib.h> before <sys/random.h>.
>         * m4/getrandom.m4 (gl_FUNC_GETRANDOM): Likewise.
>         * lib/sys_random.in.h: On macOS, include <sys/types.h> and <stdlib.h>
>         first.
>         * doc/glibc-headers/sys_random.texi: Mention the macOS problem.
>
> diff --git a/doc/glibc-headers/sys_random.texi 
> b/doc/glibc-headers/sys_random.texi
> index 1c28595..3f33962 100644
> --- a/doc/glibc-headers/sys_random.texi
> +++ b/doc/glibc-headers/sys_random.texi
> @@ -24,6 +24,9 @@ Portability problems fixed by Gnulib:
>  This header file is missing on some platforms:
>  glibc 2.24, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.11, IRIX 
> 6.5, Cygwin, mingw, MSVC 14.
>  @item
> +This header file is not self-contained on some platforms:
> +Mac OS X 10.13.
> +@item
>  This header file does not declare the @code{getrandom} function on some 
> platforms:
>  Mac OS X 10.5, FreeBSD 11.0, HP-UX 11.31, Solaris 11.0.
>  @end itemize
> diff --git a/lib/sys_random.in.h b/lib/sys_random.in.h
> index 4d12db9..290fa39 100644
> --- a/lib/sys_random.in.h
> +++ b/lib/sys_random.in.h
> @@ -23,6 +23,14 @@
>
>  #if @HAVE_SYS_RANDOM_H@
>
> +/* On Mac OS X 10.5, <sys/random.h> assumes prior inclusion of <sys/types.h>.
> +   On Max OS X 10.13, <sys/random.h> assumes prior inclusion of a file that
> +   includes <Availability.h>, such as <stdlib.h> or <unistd.h>.  */
> +# if defined __APPLE__ && defined __MACH__                  /* Mac OS X */
> +#  include <sys/types.h>
> +#  include <stdlib.h>
> +# endif
> +
>  /* The include_next requires a split double-inclusion guard.  */
>  # @INCLUDE_NEXT@ @NEXT_SYS_RANDOM_H@
>
> diff --git a/m4/getrandom.m4 b/m4/getrandom.m4
> index 9fee059..779c6ad 100644
> --- a/m4/getrandom.m4
> +++ b/m4/getrandom.m4
> @@ -1,4 +1,4 @@
> -# getrandom.m4 serial 3
> +# getrandom.m4 serial 4
>  dnl Copyright 2020 Free Software Foundation, Inc.
>  dnl This file is free software; the Free Software Foundation
>  dnl gives unlimited permission to copy and/or distribute it,
> @@ -18,8 +18,10 @@ AC_DEFUN([gl_FUNC_GETRANDOM],
>        [gl_cv_func_getrandom_ok],
>        [AC_COMPILE_IFELSE(
>           [AC_LANG_PROGRAM(
> -            [[#include <sys/random.h>
> +            [[/* Additional includes are needed before <sys/random.h> on Mac 
> OS X.  */
>                #include <sys/types.h>
> +              #include <stdlib.h>
> +              #include <sys/random.h>
>                ssize_t getrandom (void *, size_t, unsigned int);
>              ]],
>              [[]])
> diff --git a/m4/sys_random_h.m4 b/m4/sys_random_h.m4
> index 135d241..c4505b6 100644
> --- a/m4/sys_random_h.m4
> +++ b/m4/sys_random_h.m4
> @@ -1,4 +1,4 @@
> -# sys_random_h.m4 serial 2
> +# sys_random_h.m4 serial 3
>  dnl Copyright (C) 2020 Free Software Foundation, Inc.
>  dnl This file is free software; the Free Software Foundation
>  dnl gives unlimited permission to copy and/or distribute it,
> @@ -20,6 +20,9 @@ AC_DEFUN([gl_HEADER_SYS_RANDOM],
>    dnl corresponding gnulib module is not in use.
>    gl_WARN_ON_USE_PREPARE([[
>  #if HAVE_SYS_RANDOM_H
> +/* Additional includes are needed before <sys/random.h> on Mac OS X.  */
> +# include <sys/types.h>
> +# include <stdlib.h>
>  # include <sys/random.h>
>  #endif
>      ]],

On Apple platforms, when targeting specific devices like AppleTV, you
should include Apple's <TargetConditionals.h>.

You will also need <TargetConditionals.h> to determine platform
support for function calls like fork(). Not all Apple platforms
provide fork and friends.

Jeff