Unable To Locate & Open "CAN_Cfg.h"

I am new at Keil & I just inherited a project which was left behind & unfinished – meaning there is missing or unimplemented functionality. In an effort to get the code to compile I started getting rid of the warnings, which were for the most part empty function stubs w/o a proper declaration, unused functions & variables - don't worry I tagged these w/ comments so that I can go back to them later. Now I have the following error #5. I get a lot of these. My device is an LPC2468… (MCB2300)

there is a "RTX_CAN.h" file in my "C:\Keil\ARM\RV31\INC"
there is a "CAN_Cfg.h" file in my "C:\Keil\ARM\Boards\Keil\MCB2300\RL\CAN\CAN_Ex1"
there is a "CAN_Cfg.h" file in my "C:\ProdDev\VDR_4X"

Running uVision V4.22.22.0

--------- RTX_Can.h ---------

#include <RTL.h> /* RTX kernel functions & defines */
#include "CAN_Cfg.h" /* CAN Configuration */

even if I change this, it can't find the file,...
#include <CAN_Cfg.h> /* CAN Configuration */

--------- Build Output ---------

assembling SWI_Table.s...
creating preprocessor file for vdr_can.c...
C:\Keil\ARM\RV31\INC\RTX_Can.h(13): error: #5: cannot open source input file "CAN_Cfg.h": No such file or directory
compiling vdr_can.c...
C:\Keil\ARM\RV31\INC\RTX_Can.h(13): error: #5: cannot open source input file "CAN_Cfg.h": No such file or directory
creating preprocessor file for RTX_CAN.c...

--------- ---------

 RE: Unable To Locate & Open "CAN_Cfg.h"

So did you do anything to inform the compiler where you stuck that header file? You didn't expect it to magically know where every single file on your computer is, did you?

 RE: Unable To Locate & Open "CAN_Cfg.h"

Well, this (inherited) project did magically seem to have contained enough information for uVision4 to know where most of the other include files were, except of course, the one in question. So that is a bit puzzling. But, I can certainly be more specific... Thank you.

 RE: Unable To Locate & Open "CAN_Cfg.h"

So, the solution was,...

Project -> Clean Target -> Project -> Options For Target (Alt-F7) -> C/C++
Include Paths: path1;path2;path3 [Ok]
ReBuild All Target Files

Where the paths (1,2,& 3) were the ones I had specified in my original post.

 RE: Unable To Locate & Open "CAN_Cfg.h"

here the paths (1,2,& 3) were the ones I had specified in my original post.

That was quite probably not the right way to do it. Path 2 from your OP is a sample project for a specific Keil demo board. Unless you're actually using exactly that demo board, you shouldn't be referring to headers meant for that particular hardware.

 RE: Unable To Locate & Open "CAN_Cfg.h"

(I agree &) Yes, I removed the middle “path2” (device specific) & it compiled just fine. I could have sworn that didn’t work before (when running on uVision4 v4.13), that’s why it was so frustrating getting this resolved, which prompted me to post on the forum (in the 1st place - thinking there was some other issue). And so, that's why I used the "shot gun" approach & used all 3, that time around. I just recently upgraded to v4.22. But regardless, it is good to see that things work as they should.

 RE: Unable To Locate & Open "CAN_Cfg.h"

magically seem to have contained enough information

Rest assured that magic has nothing to do with it. Information like that is put into the project definition by manual labour, not divine intervention. And manual labour is prone to errors, some of which the original author may not even have noticed.

E.g. sometimes that information consists of references to files, which are relative paths based on where the project itself is stored ("..\..\main\includes"). Sometimes they're absolute path names instead ("c:\ottos_projects\project5\main\includes"). In both cases the references can become broken by moving the project around on the harddrive, if they're not done properly. As a rule of thumb paths to files outside the project's own directory tree should be absolute (or based on an environment setting), while paths to those inside should be relative.