Lack of variable declaration - CW 6.3

[ignisuti]

I recently picked-up a project created by someone else and am trying to come up to speed on the code. I came across the following line of code which confuses me. The code builds just fine in CW6.3. However this is the only instance of "BOOTLOADER_VERSION" in the project. It's not even declared! Why isn't the compiler complaining about this?

requestedData[i++]=(unsigned char)BOOTLOADER_VERSION;

Background related info:

This project is a combination of two seperate projects (Bootloader code & Application code). The code above was pulled from the Application project. However "BOOTLOADER_VERSION" is initialized (but still never declared) in the Bootloader project.

This is my first experience with CodeWarrior. Why isn't the Application code complaining about this variable not being declared?

[pgo]

Does anything interesting appear if you right-click on the mystery item?

If its a macro defined somewhere there should be an item Go to Macro definition of ...

If its a variable a similar item should be present and so on.

This assumes the project has been successfully compiled at least once.

bye

[ignisuti]

Sorry, nothing by right-clicking. Yes, this project builds just fine in CW6.3. When I take the project to CW10, I get this error: "undefined identifier 'BOOTLOADER_VERSION'"

Contacting the original programmer is not an option.

So, here is my thinking. Please let me know if this is logical or not:

CW6.3 doesn't complain (or at least had been configured by the previous programmer not to complain) about undefined identifiers. So, the programmer defined this identifier in the bootloader code knowing that the variable would be accessible in both Bootload and Application code. Then, he accesses this idnetifier in the Application code trusting that the Bootloader had already initialized this variable. The original programmer must have been thinking if he ever updated the Bootloader code, he'd update this value in only the Bootloader code and not have dual-maintenance.

If that's the case that sounds smart. Is there a way I can avoid dual maintenance since CW10 is now complaining about this in my Application code?

[ignisuti]

Okay, I finally got this figured out and wanted to report back my findings.

mcf51cn128.h defines BOOTLOADER_VERSION as a macro which points to an memory location:

#define BOOTLOADER_VERSION (*(unsigned char *)0x00801FFF)

I'm not sure why this would be in the microcontroller's header file. What is the benefit of having it here vs. defining it in my code?

Also, I'm still not sure why my search didn't find this when mcf51cn128.h was included in the project.

[bigmac]

Hello,

The code suggests that it may be a macro that is present in one ot the header files.  Have you already checked these out?

Regards,

Mac

[CrasyCat]

Hello

BOOTLOADER_VERSION is probably a macro. It is either defined in an include file or might be specified in the compiler command line using -D option.

CrasyCat

[ignisuti]

I've searched all the include files. Where do I look to see if it's a command line option?

[CrasyCat]

Hello

  - Open the project in CodeWarrior

  - Open the Target settings dialog (press ALT+F7)

  - Go to panel Compiler HC08 and examine the Command Line Arguments edit box.

CrasyCat

[ignisuti]

Sorry for my ignorance, but I'm not seeing the compiler options you guys are talking about.

I'm in the Standard Settings window. There is nothing in the left box that says "compiler". I have the following sections which can be expanded:

-Target

-Lanuage Settings

-Code Generation

-Linker

-Editor

[CrasyCat]

Hello

OK you are targeting a Coldfire chip then.

Am I right? In order to save time in your next post please specify directly the MCU you are targeting.

This will save time to everybody.

If you are building code for Coldfire, do the following:

  - Expand Language Settings

  - go toC/C++ Preprocessor and check Prefix Text there.

CrasyCat

[ignisuti]

Yes, Coldfire.

I see the section you're talking about, but the Prefix text window is empty...

[CrasyCat]

Then there is a trick somewhere and you need to consult with the original programmer or the project documentation to determine how this macro/variable is defined.

CrasyCat

[J2MEJediMaster]

1) In the IDE, go to the project settings window by typing Alt-F7.

2) On the left side of the window, choose the Compiler for <processor>. On the right of the window, the compiler settings appear.

3) Look and see if there's a Command Line Arguments option, and see what is in there.

4) You may have to consult the Build Tools Guide to decode what the arguments mean.

---Tom