https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100731
--- Comment #4 from Harald van Dijk <harald at gigawatt dot nl> --- (In reply to Richard Biener from comment #3) Yes, including <stdlib.h> is enough to get the build to pass. My last point in comment #2, however, means that that leaves things in an inconsistent state and that the right fix depends on what the project wants. There are basically two options that look equally reasonable to me: adding an include of <cstdlib> (and, although not required to fix the build, <cstdio>) and adding std:: qualifiers to everything that needs it, or adding an include of <stdlib.h> (and <stdio.h>) and changing the other existing <c*> includes to <*.h>. Happy to send a patch for whichever of these is preferred.