https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121277
--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Georg-Johann Lay <g...@gcc.gnu.org>: https://gcc.gnu.org/g:089faf54fa96565784ebdd8dfcf9c350c4c3bee5 commit r16-2591-g089faf54fa96565784ebdd8dfcf9c350c4c3bee5 Author: Georg-Johann Lay <a...@gjlay.de> Date: Mon Jul 28 21:44:06 2025 +0200 AVR: target/121277 - Don't load 0x800000 with const __flashx *x = NULL. Converting from generic AS to __flashx used the same rule like for __memx, which tags RAM (generic AS) locations by setting bit 23. The justification was that generic isn't a subset of __flashx, though that lead to surprises with code like const __flashx *x = NULL. The natural thing to do is to just load 0x000000 in that case, so that the null pointer works in __flashx as expected. Apart from that, converting NULL to __flashx (or __flash) no more raises a -Waddr-space-convert diagnostic. gcc/ PR target/121277 * config/avr/avr.cc (avr_addr_space_convert): When converting from generic AS to __flashx, don't set bit 23. (avr_convert_to_type): Don't -Waddr-space-convert when NULL is converted to __flashx or to __flash.
