How do I get the preprocessed output of a header file?

Question

I have a header file where I used:

#if defined(LINUX) || defined(ANDROID)
 pthread_t gpthread;
 #endif

Now I would like to get only the content of the header file after passing -DLINUX in compilation. Is there a way to get it? If I use:

#arm-linux-androideabi-g++ -E main.c > temp

then the conclusion confuses me a little.

+3

Whoami 15 Mar 12 at 6:31 am

3 answers

You might be interested in keeping the comments in the preprocessed output (for better readability) with

 arm-linux-androideabi-g++ -DLINUX -C -E foo.h > foo.i

then look (with editor or pager) in foo.i

The generated one foo.i

contains lines starting with #

to convey location information.

+2

Basile starynkevitch 15 Mar 12 at 6:45 am

Why not call cpp -D<something to be defined> <header file name>

directly?

0

alk 15 Mar 12 at 7:04

Timothy jones · Accepted Answer · 2012-03-15T06:33:53+0000

You can simply ask the compiler to do preprocessing in the header file only:

arm-linux-androideabi-g++ -DLINUX -E foo.h > temp