On 1/5/21 2:31 PM, Nick Savoiu via Gcc-help wrote:
Hi all, I'm trying to upgrade a codebase from GCC 9.1 to GCC 10.2 and running into weird warning/error messages in the optimized build (-O2). error: 'removed_return.213' may be used uninitialized in this function [-Werror=maybe-uninitialized] I thought that I can just downgrade the -Werror and go on but the code actually crashes on that statement.
Do you mean to say the compiler crashes or the program crashes at runtime? The former would be a bug in the compiler. The latter likely a bug in the program. The removed_return.213 name refers to a variable GCC synthesizes internally from one called removed_return in the code. It just means that GCC can't prove the variable is initialized when it's used. Initializing it on declaration should avoid the warning.
The problem code seems to be around a macro that looks like this: extern bool IsDebugOn(); #define debug IsDebugOn() && std::cout and that's used like this: debug << "print something" << std::endl; The error goes away if I use if (IsDebugOn()) debug << "print something" << endl; so I guess the shortcircuited && somehow makes a difference. Unfortunately this happens way deep in the code and any attempts so far to extract the code such that it still exhibits the problem have failed. I'd appreciate any pointers.
If you suspect a bug in GCC then, at a minimum, we need to see the full GCC output (the warning/error, followed by any informational notes and stack trace if GCC dies with an ICE). Better yet would be a translation unit (the result of preprocessing the file with -E) and the full command line so we can reproduce the problem. Since you mentioned <iostream> it's probably going to be too big for the list so opening a bug report and attaching the translation unit to it would be preferable. Martin
