Hi Martin, the program crashes, not GCC. My code does not contain any 'removed_return'. I suspect that it's a GCC thing so it would probably not appear in a -E output. I'll try again to extract the behavior from the codebase. Nick On Wednesday, January 6, 2021, 9:20:19 AM PST, Martin Sebor <msebor@xxxxxxxxx> wrote: 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
