[Bug libstdc++/11953] _REENTRANT defined when compiling non-threaded code.

["marc dot waeckerlin at siemens dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #36 from marc dot waeckerlin at siemens dot com  2005-11-29 09:27 -------
New information:

_REENTRANT is definitively defined in the headers:

> echo "" | g++ \
    -I /usr/include/c++/4.0.2 -I /usr/include/c++/4.0.2/i586-suse-linux \
    -E -dM -c - | grep REENTRANT
> echo "" | g++ \
    -I /usr/include/c++/4.0.2 -I /usr/include/c++/4.0.2/i586-suse-linux \
    -E -dM -c -pthread - | grep REENTRANT
#define _REENTRANT 1
> echo "#include<iostream>" | g++ \
    -I /usr/include/c++/4.0.2 -I /usr/include/c++/4.0.2/i586-suse-linux \
    -E -dM -c - | grep REENTRANT
#define _REENTRANT 1
#define _POSIX_REENTRANT_FUNCTIONS 1

--> So, without "#include <iostream>" it works as expected!

This opens a new possibility to work around this bug:

--------------file.cpp
#define GCC_BUGFIX _REENTRANT
#include <iostream>
#include ...
#undef _REENTRANT
#define _REENTRANT GCC_BUGFIX

#ifdef _REENTRANT
  ...
#endif
----------------------



> g++ -v
Using built-in specs.
Target: i586-suse-linux
Configured with: ../configure --enable-threads=posix --prefix=/usr
--with-local-prefix=/usr/local --infodir=/usr/share/info
--mandir=/usr/share/man --libdir=/usr/lib --libexecdir=/usr/lib
--enable-languages=c,c++,objc,f95,java,ada --disable-checking
--with-gxx-include-dir=/usr/include/c++/4.0.2 --enable-java-awt=gtk
--disable-libjava-multilib --with-slibdir=/lib --with-system-zlib
--enable-shared --enable-__cxa_atexit --without-system-libunwind
--host=i586-suse-linux
Thread model: posix
gcc version 4.0.2 20050901 (prerelease) (SUSE Linux)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11953