没有调试符号的程序崩溃，运行正常（在任何情况下都没有优化或任何东西）

Question

I've come across a very baffling crash and having trouble tracing it in my program.

I have no idea where its source is, because whenever I attempt to link with the /debug flag in order to debug with debug symbols, the crash disappears!

This seems to be independent of optimizations (I've compiled with /Od to disable compiler optimizations and I'm not using link-time code generation) and also independent of debug information itself (I'm compiling with /Zi ). For some reason, when the linker is called without the /debug flag, everything behaves differently.

What could possibly be causing this?

Answer 1

It turned out the culpirit was merging of static const int fields by the linker.

Apparently, if you have multiple static const fields of the same type and value, the linker will merge them, but only if you don't link debug symbols.

I was using the addresses of such fields to distinguish between them, and as it turned out they all looked the same to the linker, and hence to the rest of the code.

How did I figure this out?
Lots and lots of print statements (hours) led me to realize that the wrong code is being executed, until I finally realized the cause.