Debugger unable to view large structs

Hi again Martin,

We've identified an issue with the (default) LLVM DWARF parser in Arm DS Debugger.
With large structs, when the offset to a member reaches a certain size, it gets put into a different datatype, which is then being interpreted incorrectly by the Debugger.  Unfortunately, this issue affects all recent versions of Arm DS, including the new version 2024.0.

The workaround is to switch to the old DWARF parser.
Select Window > Preferences, then Arm DS > Debugger > Dwarf Parser, then untick "Use LLVM Dwarf Parser".

I've tested that this works for images compiled with Arm Compiler 6.
If you are compiling with a recent GCC, you may need to compile with the option -gdwarf-4 to select DWARF4 debug tables, because the old Dwarf Parser doesn't support DWARF5.

Is the ordering of the members critical in your struct?  If not, then an alternative workaround could be to move the members that you want to debug to the top of the struct.

I'm sorry that you've hit this issue, but thank you for reporting it.  We'll endeavor to fix this in the next release.

Stephen

Hi again Martin,

We've identified an issue with the (default) LLVM DWARF parser in Arm DS Debugger.
With large structs, when the offset to a member reaches a certain size, it gets put into a different datatype, which is then being interpreted incorrectly by the Debugger.  Unfortunately, this issue affects all recent versions of Arm DS, including the new version 2024.0.

The workaround is to switch to the old DWARF parser.
Select Window > Preferences, then Arm DS > Debugger > Dwarf Parser, then untick "Use LLVM Dwarf Parser".

I've tested that this works for images compiled with Arm Compiler 6.
If you are compiling with a recent GCC, you may need to compile with the option -gdwarf-4 to select DWARF4 debug tables, because the old Dwarf Parser doesn't support DWARF5.

Is the ordering of the members critical in your struct?  If not, then an alternative workaround could be to move the members that you want to debug to the top of the struct.

I'm sorry that you've hit this issue, but thank you for reporting it.  We'll endeavor to fix this in the next release.

Stephen

Hi Stephen,

Sorry that I didn't reply earlier. First off, unticking "Use LLVM Dwarf Parser" indeed fixed the bug and now I am able to see all struct members!
Great to hear that you could reproduce the error and are working on a fix.

About the size in my original post, I somehow misread the numbers and thought the size shown in ARM DS was smaller than the actual size in bytes.

I did not encounter members shown as "Optimized Away" (apart from occasions where I assume they acutally were optimized).

Thanks for your fast help and the workaround.

Kind Regards

Martin