Re: egcs-19980715 doesn't recognize '__linux__' in C++ code

[Jeffrey A Law <law at cygnus dot com>]

  In message <Pine.LNX.4.00.9807181340400.2148-100000@progress.plw.net>you writ:
  >  I compilled, installed egcs-19980715(egcs-2.91.50) on i586-pc-linux-gnu
  > system(RH5.1, glibc-2.0.94-4, libg++-2.8.2-980708, ...).
  >  It compiles linux kernel 2.1.108, 2.1.109, and compiled kernels boots
  > OK.
  >  But 'make -k check' shows gcc(egcs-19980715) cannot recognize
  > '__linux__' in libg++/etc/lf/screen.cc and fails to compile screen.cc.
  >  It works well with 'LINUX' or '__LINUX__', but, I think, these are not
  > used frequently on linux system. 
Huh?  __linux__ is defined by default on linux systems.  Look at the
output from running g++ -v on a file:

g++ -v foo.C
Reading specs from /usr/egcs/lib/gcc-lib/i686-pc-linux-gnu/egcs-2.91.50/specs
gcc version egcs-2.91.50 19980714 (gcc2 ss-980609 experimental)
 /usr/egcs/lib/gcc-lib/i686-pc-linux-gnu/egcs-2.91.50/cpp -lang-c++ -v -undef -D__GNUC__=2 -D__GNUG__=2 -D__cplusplus -D__GNUC_MINOR__=91 -D__ELF__ -Dunix -Dlinux -D__ELF__ -D__unix__ -D__linux__ -D__unix -D__linux -Asystem(posix) -D__EXCEPTIONS -Asystem(unix) -Acpu(i386) -Amachine(i386) -Di386 -D__i386 -D__i386__ -Di686 -Dpentiumpro -D__i686 -D__i686__ -D__pentiumpro -D__pentiumpro__ foo.C /tmp/cckT6dPW.ii

Note carefully -D__linux__.

This is the desired behavior.


  >  This problem seems to appear for the first time in this version of egcs.
  > 
  > 
  >  1. the code of screen.cc
  > --------------------------------------------------------------------
  > #if !defined(hpux) && !defined(__linux__) && !defined(_AIX41)
  > extern "C" int tgetent(void *, const char *);
  > extern "C" int tgetnum(const char*);
  > extern "C" char *tgetstr(const char *, char**);
  > #endif
  > --------------------------------------------------------------------
This code says *NOT* to provide prototypes for those functions on a
linux system.  But the code still uses those functions.  This is a bug
in the libg++ test code, not egcs.

jeff