kc3-lang/gnulib/doc/posix-functions/environ.texi

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• Hash : cf56f8f6
  Author :
  Date : 2018-01-31T09:04:52
  

  environ: Fix link error on 64-bit Cygwin.
  
  * lib/unistd.in.h (environ): On Cygwin, redeclare with the
  __declspec(dllimport) attribute.
  * doc/posix-functions/environ.texi: Mention the Cygwin problem.
  

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• doc/posix-functions/environ.texi

• @node environ
  @section @code{environ}
  @findex environ
  
  POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/environ.html}
  
  Gnulib module: environ
  
  Portability problems fixed by Gnulib:
  @itemize
  @item
  POSIX does not require this variable to be declared, and it is indeed not
  declared on some platforms:
  Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, IRIX 6.5, Solaris 11.3.
  @item
  On Mac OS X 10, this variable is not declared.  Up to Mac OS X 10.4, one can use
  @smallexample
  extern char **environ;
  @end smallexample
  to get the variable declared.  This does not work any more, however, in
  shared libraries on Mac OS X 10.5.  Here is a workaround: Instead, one can use
  @smallexample
  #include <crt_externs.h>
  #define environ (*_NSGetEnviron())
  @end smallexample
  This works at all versions of Mac OS X.
  @item
  On Cygwin in 64-bit mode, references to this variable cause a link error when
  the option @code{-Wl,--disable-auto-import} is in use.
  @end itemize
  
  Portability problems not fixed by Gnulib:
  @itemize
  @item
  The address of this variable is not a compile-time constant on some platforms:
  mingw.
  @end itemize
  

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