Problems compiliing c++ code using cygwin

Question

I am trying to compile some source code in cygwin (in windows 7) and get the following error when I run the make file

g++ -DHAVE_CONFIG_H -I. -I..  -I..  -Wall -Wextra -Werror -g -O2 -MT libcommon_a  Fcntl.o -MD -MP -MF .deps/libcommon_a-Fcntl.Tpo -c -o libcommon_a-Fcntl.o `test -f 'Fcntl.cpp' || echo './'`Fcntl.cpp
Fcntl.cpp: In function int setCloexec(int):
Fcntl.cpp:8: error: 'F_GETFD' was not declared in this scope
Fcntl.cpp:8: error: 'fcntl' was not declared in this scope
Fcntl.cpp:11: error: 'FD_CLOEXEC' was not declared in this scope
Fcntl.cpp:12: error: 'F_SETFD' was not declared in this scope
make[4]: *** [libcommon_a-Fcntl.o] Error 1
make[4]: Leaving directory `/abyss-1.1.2/Common'
make[3]: *** [all-recursive] Error 1
make[3]: Leaving directory `/abyss-1.1.2'
make[2]: *** [all] Error 2
make[2]: Leaving directory `/abyss-1.1.2'
make[1]: *** [.build-conf] Error 2
make[1]: Leaving directory `/cygdrive/c/Users/Martin/Documents/NetBeansProjects/abyss-1.1.2_1'
make: *** [.build-impl] Error 2

The problem file is:-

#include "Fcntl.h"
#include <fcntl.h>


/* Set the FD_CLOEXEC flag of the specified file descriptor. */
int setCloexec(int fd)
{
 int flags = fcntl(fd, F_GETFD, 0);
 if (flags == -1)
  return -1;
 flags |= FD_CLOEXEC;
 return fcntl(fd, F_SETFD, flags);
}

I don't understand what is going on, the file fcntl.h is available and the varaiables that it says were not declared in this scope do not give an error when I compile the file on its own

Any help would be much appreciated

Many Thanks

Answer 1

I've not built things with Cygwin, so this might be off-base, but considering that you're building on Windows, which has a case-insensitive filesystem, are you sure that the compiler can tell the difference between your header Fcntl.h and the system header fcntl.h? It might just be including your header twice and never getting the system header.

Answer 2

What's up with those #include statements? It seems like you have a header file in your project called Fcntl.h, is that right? Does it have include guards in it? If it does, maybe you're accidentally using the same guard as the built-in header, and as a result not getting its contents. Cygwin normally runs on a case-insensitive filesystem, so even giving those headers similar names like that is probably dangerous.