RE: GCC compiler in a cygwin environment.

[Suman Kumar Ray <smnray at yahoo dot com>]

> I had this problem too. Try calling with g++ to
> force compilation and
> linking as C++. gcc should do the right thing based
> on your file extension
> though ? Sorry I can't be of more help :)

 What I have observed is 

a> For compilation only , i.e. for -c, g++ treats all
files
as c++ file. Where  gcc treats .c etc. files as c file
and .C, .cpp etc. as C++ file, and compile
accordingly. As far as C++ support in compiler is
concerned, there is no difference in gcc and g++

b> For linking, g++ passes by default extra library
for C++, (and someone says math library too), which
gcc does not pass. That is why even if someone can
compiler C++ using gcc, but there will be link error
for c++ library if you do not use g++ as linker
driver.

Thus if someone has a.cpp file, contains class etc.,
it can be build by either of following two commands
  1> $>gcc -c a.cpp 
     $>g++ a.o

        or

  2> $>g++ a.cpp

I have not seen g++ source. My observation is based on
manuals and old help e-mails. In one one old e-mail, I
have found that it has been complained that for math
header file, g++ uses different path than gcc. But in
cygwin, for 2.95.3 gcc and g++, I have not found that
difference.
 Thanks,
Suman Ray


--- Scott Sinclair <scott.sinclair@umgeni.co.za>
wrote:
> Hi
> 
> > -----Original Message-----
> > From: Johansson Mikael (mj)
> [mailto:mikael.mj.johansson@volvo.com]
> > Sent: 19/03/2002 14:56
> > To: gcc-help@gcc.gnu.org
> > Subject: GCC compiler in a cygwin environment.
> > 
> > 
> > Hello.
> > 
> > I have gcc installed in a cygwin environment on
> win NT.
> > 
> > I cant compile c++ -code to executables in that
> environment.
> > From the linker stage I get the following error
> message:
> > 
> > /usr/tmp/ccRILazb.o(.text+0x1f):Hello.cc:
> undefined reference 
> > to `endl(ostream &)'
> > /usr/tmp/ccRILazb.o(.text+0x2c):Hello.cc:
> undefined reference 
> > to `cout'
> > /usr/tmp/ccRILazb.o(.text+0x31):Hello.cc:
> undefined reference 
> > to `ostream::operator<<(char const *)'
> > /usr/tmp/ccRILazb.o(.text+0x44):Hello.cc:
> undefined reference 
> > to `getch'
> > 
> > If anyone has a clue on this please let me know.
> > 
> > Best regards.
> > MJ
> > 
> 
> I had this problem too. Try calling with g++ to
> force compilation and
> linking as C++. gcc should do the right thing based
> on your file extension
> though ? Sorry I can't be of more help :)
> 
> Scott


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