Local variables displayed incorrectly

Peter,

I checked and the issue you mentioned seems strictly related to SDSCM00038624 - a fix is implemented and is planned for release 4.2.2.

Best regards,

Rafael

Peter,

I got confused. SDSCM00038624 only refers to the message "unknown register ID", but not to the fact the local variables stored in registers do not show in the Watch window.

In this case when the optimizer stores variables in registers for performance reasons, the debug information is lost and the watch window has no way to get their values anymore. This is more likely to occur if the local variables are parameters passed to the function.

If you see no disruption in code execution, then it is a normal behaviour of the optimization process. Just checking, are you able to see the local variable in the watch window if you disable the optimizer?

Regards,

Rafael

Part 1:
Rafael, how do you disable the optimizer?  From what I can see in TI doc SLAU132C, MSP430 Optimizing C C++ Compiler v 3.1 User's Guide (Rev. C), optimizations are as off as they can be - opt_level=0 and opt_for_speed=4 as per my post.  Which happens to be the default values.

I've created a new project after installing 4.2.1 and made the following settings changes:
code_model: large
data_model: large
near_data: globals
Linker/basic options/stack size             768
Linker/basic options/heap size             160
Set mV target = 3300
Select "lnk_msp430f5438"                    Properties / CCS Build / General / Linker Command File
Select "rts430xl.lib"                     Properties / CCS Build / General / Runtime Support Library
CCS Debug/Target/Disable Interrrupts        When Source Stepping
opt_level=0
opt_for_speed=4

Part 2:
Re this part "In this case when the optimizer stores variables in registers for performance reasons, the debug information is lost and the watch window has no way to get their values anymore. This is more likely to occur if the local variables are parameters passed to the function."
if a value is in register variable, my attitude is if the debugger is on the line of the function call the variable is in scope, stored in a register as it's passed to the function, and you should be able to see it's value.  Don't see how the debug info is lost.  Eg, noting that the variable maybe assigned R9 (from list file) but the function called requires it in R15. The debugger can keep track of this.  I appreciate how the compiler optimises the register variable to limit their scope to the minimum required.  Seen this in the assembler.  Maybe you can explain this further.

In your post I presume Watch window meant Local window/tab.

Peter,

The optimizer is turned off if you leave the option Optimization Level as completely blank in the Build Options. The optimizer is turned on when the level is set from 0 to 3.

While variables stored in registers are not displayed in the Local/watch window, I will have to leave to the compiler experts to cover the exact reason of why this happens or was designed this way. However, keep in mind the debugger interface encompasses several device families, therefore while it is straightforward to track down a variable in MSP, the complexity increases exponentially when dealing with other platforms.

Cheers,

Rafael