VLAs (variable-length arrays) are a C99 feature and were never standardised for C++.
There are better alternatives in C++ (mainly std::vector). Enable the warnings
so no new ones can be introduced.
-Wno-cast-function-type:
Signal handler code relies on this.
-Wno-type-limits:
Some of the color space conversion code in zm_image throws this warning. To not break anything let's ignore this warning for the time being.
Note that clang enables -Woverloaded-virtual with -Wextra. To not flood the GCC build log with warnings let's not enable this at the moment.
This will be done in a second step, when the currently throwing code will be cleaned up.
Peter Keresztes Schmidt