It strikes me that (2) isn't necessarily even what you want. Optimization will change the character of the program, often radically. Should the debugger reflect

It strikes me that (2) isn't necessarily even what you want. Optimization will change the character of the program, often radically. Should the debugger reflect the source code says it should do or what the optimized code is actually doing? This is apparent in C++ when you look at the optimized output on Compiler Explorer: it attempts to color assembly based on the source lines, and some source lines get strewn about the resulting assembly.