[lldb-dev] "expression" for gcc compiled code

Sean Callanan scallanan at apple.com
Wed Jul 21 11:16:52 PDT 2010


thanks for testing the expression code!

At this point, the expression parser is too rudimentary to have (interesting) compiler-specific bugs :)  We're retooling it to use LLVM IR and the JIT as opposed to the current, AST-based mechanism which handles C/C++ constructs and types on a case-by-case basis.  This will make it much more general.  Once that functionality gets in, I would welcome any problem reports you can provide.

So in summary, it's not a simple problem, and evaluating expressions in general is fundamentally broken in various ways.  But we're working on it.


On Jul 21, 2010, at 10:16 AM, Matthias Neeracher wrote:

> While "variable list" works when debugging my gcc compiled program, I'm not having much luck using "expression". No matter what expression I try, as soon as I refer to any variables, I get something like:
> error: couldn't evaluate DWARF expression: DW_OP_APPLE_extern(0) opcode encountered with no decl map.
> Simple stuff like "expr 1+1" works, though.
> Is evaluating expressions in gcc (as opposed to llvm-gcc or clang), compiled code fundamentally broken, or is this likely to be a simple problem that would be reasonably easy for me to trace down (I'm getting somewhat comfortable running lldb under gdb by now ;-) ?
> Matthias
> _______________________________________________
> lldb-dev mailing list
> lldb-dev at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev

More information about the lldb-dev mailing list