Hello, I'm running into a rather crazy problem that I can't minimize enough to create a bug report for, so I'd like to ask here if anybody might have any ideas about it by chance. The problem is that the behaviour of some piece of C++ code changes, when compiling using MinGW g++ 7.2 (20180123 version from Debian Buster) and "-O2", depending on whether _both_ of -Wall and -Woverloaded-virtual command line options are specified or not. I.e. the code behaves in the same way (and the generated assembly is identical) when compiling with just "-O2", or with "-O2 -Wall", or with "-O2 -Woverloaded-virtual", but when all of "-O2 -Wall -Woverloaded-virtual" are used, the code behaviour changes (it's a unit test and it starts failing) and the assembly for the functions in which the test fails looks very different. Unfortunately I can't reduce the program to anything reasonably small as just about any changes to the source file, including to the clearly unrelated stuff, make the bug disappear. I've tried using delta tool recommended by gcc wiki, but it didn't produce anything useful after running for many hours (it reduced the test case from 85801 initial lines of preprocessed code to ~67000, which is not really very useful...). Does anyone know what else could I try doing? Or maybe someone already knows how does the combination of these 2 warning switches affect the code generation (which is something I'd naïvely expect to be impossible)? Thanks in advance for any help! VZ
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