@atax1a @regehr

For those missing context:

AMD GPUs place (placed?) their stack memory at address 0, which meant 0 was a valid memory address. This caused a bunch of problems in LLVM because LLVM assumes that a pointer at address 0 is invalid.

The C spec is more fun here. An integer constant expression of 0 is a null pointer but an implementation is free to determine that a constant expression that turns into some entirely different bit pattern when compiled. Some mainframes do this and null pointers are not represented as zero.

For CHERI C we aim to implement most of the 'de facto' C standard (i.e. all of the stuff that C programmers expect, even if the standard says they shouldn't). This includes being able to memset a struct with zero and have all of the pointer fields be filled with nulls.