C_INCLUDE_PATH and gcc -I option

[Madhur]

Hi,

I would like to know the difference between using the
C_INCLUDE_PATH and using the -I option with compilers. How are they
different?

The problem which I am facing is that I am having a
source base which uses python. I am currently enabling compile time
option _POSIX_C_SOURCE in my Makefile. The compilaiton fails if i
include -I option to /usr/include/python2.4

/usr/include/python2.4/pyconfig-32.h:838:1: error: "_POSIX_C_SOURCE"
redefined

but if i do

export C_INCLUDE_PATH=/usr/include/python2.4

I do not face any compilation issues.

I would like to know if there is anything i am missing on this.
Regards,
Madhur

[Antoninus Twink]

On 9 Jun 2008 at 13:46, Madhur wrote:

The problem which I am facing is that I am having a
source base which uses python. I am currently enabling compile time
option _POSIX_C_SOURCE in my Makefile. The compilaiton fails if i
include -I option to /usr/include/python2.4

/usr/include/python2.4/pyconfig-32.h:838:1: error: "_POSIX_C_SOURCE"
redefined

but if i do

export C_INCLUDE_PATH=/usr/include/python2.4

I do not face any compilation issues.

[guess]
Does your build procedure include running some python script that reads
the C_INCLUDE_PATH envrionment variable, but doesn't see -I... in
CFLAGS?
[/guess]

[Madhur]

There aren't any python scripts which reads C_INCLUDE_PATH.

On Jun 9, 7:04 am, Antoninus Twink <[e-mail]:

On 9 Jun 2008 at 13:46, Madhur wrote:

The problem which I am facing is that I am having a
source base which uses python. I am currently enabling compile time
option _POSIX_C_SOURCE in my Makefile. The compilaiton fails if i
include -I option to /usr/include/python2.4

/usr/include/python2.4/pyconfig-32.h:838:1: error: "_POSIX_C_SOURCE"
redefined

but if i do

export C_INCLUDE_PATH=/usr/include/python2.4

I do not face any compilation issues.

[guess]
Does your build procedure include running some python script that reads
the C_INCLUDE_PATH envrionment variable, but doesn't see -I... in
CFLAGS?
[/guess]

[Ben Bacarisse]

Madhur <ma********@gmail.comwrites:

I would like to know the difference between using the
C_INCLUDE_PATH and using the -I option with compilers. How are they
different?

Best not to ask this sort of question. It asks for an essay on the
differences when there may be only one detail that matters.

The problem which I am facing is that I am having a
source base which uses python. I am currently enabling compile time
option _POSIX_C_SOURCE in my Makefile. The compilaiton fails if i
include -I option to /usr/include/python2.4

/usr/include/python2.4/pyconfig-32.h:838:1: error: "_POSIX_C_SOURCE"
redefined

but if i do

export C_INCLUDE_PATH=/usr/include/python2.4

I do not face any compilation issues.

That is clear enough but it is better asked in gnu.gcc.help. I have
sent this there and set followups-to.

You can make it non-python specific if you like. I have just got the
same behaviour from:

--- m.c ---
#define MACRO 0
#include <x.h>

MACRO
-----------
--- x.h ---
#define MACRO 1
-----------

$ gcc -E -I. m.c

gives the expected error, but setting C_INCLUDE_PATH=. makes the error
vanish (even if the -I. parameter is kept).

--
Ben.