Inconsistent values of (CLOCK_REALTIME, CLOCK_MONOTONIC) vs (SYS_CLOCK_REALTIME, SYS_CLOCK_MONOTONIC) cause invalid clockid errors with ARC MWDT toolchain

[M-Moawad]

Describe the bug

When building with the ARC MWDT toolchain, some tests fail because of inconsistent clockid values between the toolchain headers and Zephyr’s internal definitions.

Specifically:

CLOCK_REALTIME and CLOCK_MONOTONIC come from the toolchain header:

#define CLOCK_REALTIME 0
#define CLOCK_MONOTONIC 1

Zephyr internally defines:

#define SYS_CLOCK_REALTIME   1
#define SYS_CLOCK_MONOTONIC  4

and tries to map them in include/zephyr/posix/time.h:

#ifndef CLOCK_REALTIME
#define CLOCK_REALTIME SYS_CLOCK_REALTIME
#endif

#ifndef CLOCK_MONOTONIC
#define CLOCK_MONOTONIC SYS_CLOCK_MONOTONIC
#endif

Because the toolchain headers already define these macros, the #ifndef guards fail, so the fallback Zephyr definitions are never applied.

Tests and code end up mixing:

• CLOCK_REALTIME=0 (from toolchain)

• SYS_CLOCK_REALTIME=1 (used in Zephyr kernel)

• CLOCK_MONOTONIC=1 (toolchain)

• SYS_CLOCK_MONOTONIC=4 (Zephyr)

This mismatch causes functions like:

clock_gettime(CLOCK_REALTIME, &tp);

to pass wrong clockid into Zephyr, leading to errors like EINVAL (invalid clock ID).

Regression

• This is a regression.

Steps to reproduce

Use the ARC MWDT toolchain (or any toolchain that defines CLOCK_REALTIME and CLOCK_MONOTONIC with different values, e.g., 0 and 1 instead of Zephyr’s 1 and 4).

Build and run a test like tests/posix/semaphores or tests/lib/c_lib/thrd:

west twister -p <your_arc_board> -s portability.posix.semaphores

or

west twister -p <your_arc_board> -s libraries.libc.c11_threads.picolibc.notls

Relevant log output

Booting Zephyr OS build v4.2.0-rc3
Running TESTSUITE posix_semaphores
START - test_named_semaphore

Assertion failed at WEST_TOPDIR/zephyr/tests/posix/semaphores/src/main.c:58: semaphore_test: (clock_gettime(CLOCK_REALTIME, &abstime) not equal to 0)
clock_gettime failed
FAIL - test_named_semaphore in 0.702 seconds
START - test_semaphore

Assertion failed at WEST_TOPDIR/zephyr/tests/posix/semaphores/src/main.c:58: semaphore_test: (clock_gettime(CLOCK_REALTIME, &abstime) not equal to 0)
clock_gettime failed
FAIL - test_semaphore in 0.006 seconds
TESTSUITE posix_semaphores failed.

------ TESTSUITE SUMMARY START ------

SUITE FAIL - 0.00% [posix_semaphores]: pass = 0, fail = 2, skip = 0, total = 2 duration = 0.708 seconds

FAIL - [posix_semaphores.test_named_semaphore] duration = 0.702 seconds
FAIL - [posix_semaphores.test_semaphore] duration = 0.006 seconds
------ TESTSUITE SUMMARY END ------

Impact

Annoyance – Minor irritation; no significant impact on usability or functionality.

Environment

OS: Linux
Toolchain (e.g Zephyr SDK, ...): arcmwdt
Commit SHA or Version used: Main 322da1d

Additional Context

This issue was introduced by PR #90096