Precompiled header files

 Precompiled header files

Hello forum,
I want to take use of precompiled header files in my project. My project is split into two parts. A library part and an application part.

The application part is using the library part by including a single header file called library.hpp. library.hpp contains a ton of includes.

I want to create a pch file out of library.hpp and force the ARM compiler to use that instead of recompiling each header file over and over again.
My problem is that I don't get uVision3 configured in a way that this pch file is properly created.

Here is what I did so far:
- create a cpp file called library.cpp
- configured the library.cpp C/C++ options with --create_pch=library.pch
- configured the overall project C/C++ options with --use_pch=library.pch

When I compile the project the library.pch is created but for each cpp file that is processed the compiler outputs a warning that the pch file has been created with compiler options different from current options.

Please can you give me a hint what I am doing wrong or direct me to any tutorials, sample projects?
I am using Cortex-M3 on ARM-MDK4.0 with uVision 3.9
Thanks a lot in advance and best regards
Jan

 RE: Precompiled header files

Turn on listing files, so you get *.txt files in the output directory. At the top of each *.txt file, you will see a list of compiler options used for compiling that source file.

Is there any difference between compiling the source files in the library and the source files using the library?

 RE: Precompiled header files

Per,
Your forum name is prepended by 2 'c' characters :-)

 RE: Precompiled header files

A common problem with this forum. The web form has the "First Name" field selected when you try to reply. Then you'll have to wait for a later post to try to remember to fix it.

 RE: Precompiled header files

@cc: Thanks for your quick response I will try that as soon as I am back in the office today!

 RE: Precompiled header files

Hi Per,
I tried to get a clue out of the list files but can't say there are differences.

Actually I think that I do something wrong when creating the pch file.

How would you configure a project for using pch files?

Thanks a lot in advance and best regards.
Jan

 RE: Precompiled header files

Hi again,
here's a short update of what I did so far:

I have three files:
main.cpp
stdafx.cpp
stdafx.hpp

In C/C++ options I added a "Misc Control" to main.cpp: --use_pch=stdafx.pch

In C/C++ options I added a "Misc Control" to stdafx.cpp:
--create_pch=stdafx.pch

my main.cpp looks like this:

#include "stdafx.hpp"
int main(void)
{ }

my stdafx.cpp looks like this:
#include "stdafx.hpp"

my stdafx.hpp looks like this:
#include "..."
#include "..."
// ... tons of includes

When I build my mini project I am getting the following warning:
main.cpp: Warning: #629-D: the command line options do not match those used when precompiled header file "stdafx.pch" was created

I really don't know how to get this pch thing working with Keil!

Please can anyone help me and direct me how to set these things up correctly?
Thanks a lot in advance!
Jan