"Can use" is different from "can use productively." Technically if it's compiled to C/C++ you can use gdb/lldb etc, BUT the compiled version may be so drastically different from the input that it's effectively useless to track down logic errors in the original.
C has this nice preprocessor directive that indicate the actual source code:
#line 42 "actual_source.lang"
Subsequent tools like gdb/lldb pick up on that, and point to your source code instead of the intermediate C. So you don't care that the C code is wildly different from your own, the tools can still point to to the right place.
