c79cee7136
__builtin_unreachable doesn't raise any compile-time warnings/errors on its own, so problems with its usage can't be easily detected. While it would be nice for this situation to change and compilers to at least add a warning for trivial cases where local state means the instruction can't be reached, this isn't the case at the moment and likely will not happen. This commit adds an __assert_unreachable, whose intent is incredibly clear: it asserts that this instruction is unreachable. On INVARIANTS builds, it's a panic(), and on non-INVARIANTS it expands to __unreachable(). Existing users of __unreachable() are converted to __assert_unreachable, to improve debuggability if this assumption is violated. Reviewed by: mjg Differential Revision: https://reviews.freebsd.org/D23793 |
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| .. | ||
| ow_temp.c | ||
| ow.c | ||
| ow.h | ||
| owc_gpiobus.c | ||
| owll_if.m | ||
| owll.h | ||
| own_if.m | ||
| own.h | ||
| README.txt | ||
Quick Design Document for 1-wire bus In new bus terms, 1-wire devices are attached to 1-wire buses (ow) which are attached to a one wire bridge (owc). The implementation follows the terminology used in the Maxim AN927 Application note which defines the 1-wire bus as implemented for the iButton product. This is considered to be the canonical definition of the 1-wire bus. This means that the 1-wire bridge will implement the owll(9) interface. ow is one wire. ll is for Link Level to mirror the ISO stack terminology used by AN927. The 1-wire bus is implemented in the ow(4) device, which implements the own(9) interface (n for network, the layer described in the AN927). The presentation layer and above is the responsibility of the client device drivers to implement. Client drivers may only call the own(9) interface. The ow(4) driver calls the owll(9) interface and implements the own(9). $FreeBSD$