libocca fails to build with Clang on < 10.12: clock_get_time, mach_port_deallocate

[barracuda156]

Two issues are there:

/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_devel_libocca/libocca/work/occa-1.5.0/src/occa/internal/utils/sys.cpp:94:7: error: use of undeclared identifier 'clock_get_time'; did you mean 'clock_gettime'?
      clock_get_time(cclock, &ct);
      ^~~~~~~~~~~~~~
      clock_gettime
/opt/local/include/LegacySupport/time.h:55:12: note: 'clock_gettime' declared here
extern int clock_gettime( clockid_t clk_id, struct timespec *ts );
           ^
/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_devel_libocca/libocca/work/occa-1.5.0/src/occa/internal/utils/sys.cpp:94:30: error: cannot initialize a parameter of type 'struct timespec *' with an rvalue of type 'mach_timespec_t *' (aka 'mach_timespec *')
      clock_get_time(cclock, &ct);
                             ^~~
/opt/local/include/LegacySupport/time.h:55:62: note: passing argument to parameter 'ts' here
extern int clock_gettime( clockid_t clk_id, struct timespec *ts );
                                                             ^

And:

/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_devel_libocca/libocca/work/occa-1.5.0/src/occa/internal/utils/sys.cpp:96:7: error: use of undeclared identifier 'mach_port_deallocate'
      mach_port_deallocate(mach_task_self(), cclock);
      ^

(legacysupport currently is used for < 10.7, but with Clang build it does not help.) Example of the log: ​https://build.macports.org/builders/ports-10.6_x86_64-builder/builds/146182/steps/install-port/logs/stdio

[ryandesign (Ryan Carsten Schmidt)]

clock_gettime is a standard cross-platform function that made its first appearance on macOS in version 10.12. legacysupport provides an implementation of it for 10.11 and earlier systems. But this port isn't including legacysupport in order to get clock_gettime; it's including it to get getline.

clock_get_time on the other hand is a macOS (Mach kernel) function available since version 10.0: ​https://developer.apple.com/documentation/kernel/1420035-clock_get_time

mach_port_deallocate is too: ​https://developer.apple.com/documentation/kernel/1578777-mach_port_deallocate

If the build says these functions are undeclared, the fix might simply be to include the header where they're declared, which is <mach/mach_port.h>. However I see there is also a <mach/mach.h> which includes mach_port.h among other things; maybe it is preferred to include mach.h.

I see that occa already does include Mach headers in src/occa/internal/utils/sys.cpp, and around there I see another instance if #ifdef __clang__ that might need the same fix as the one already being applied further down in the file by 0003-Check-for-CLOCK_UPTIME_RAW-on-macOS-before-using-it.patch.

[ryandesign (Ryan Carsten Schmidt)]

Don't really know why this code is checking for __clang__ at all in either of the two places. All we care about is whether the OS has clock_gettime_nsec_np, which was introduced in macOS 10.12 along with clock_gettime (although legacysupport doesn't have clock_gettime_nsec_np; see #61691).

[ryandesign (Ryan Carsten Schmidt)]

untested guess of a fix

[barracuda156]

Replying to ryandesign:

Don't really know why this code is checking for __clang__ at all in either of the two places. All we care about is whether the OS has clock_gettime_nsec_np, which was introduced in macOS 10.12 along with clock_gettime (although legacysupport doesn't have clock_gettime_nsec_np; see #61691).

Me neither, but I assumed there was some sense behind that. The issue was, I guess, that I should have amended the define in both places identically, and since that was not done, needed headers for clock_get_time and mach_port_deallocate did not get included on systems without CLOCK_UPTIME_RAW in combination with Clang. Since neither Macports CI nor my local testing machine fit this, that went unnoticed.

I will amend the patch: indeed, why check for Clang there at all.

[ryandesign (Ryan Carsten Schmidt)]

Alternately, if you want to guard against the port's behavior possibly changing if #61691 gets implemented, instead of checking if CLOCK_UPTIME_RAW is defined, you could check if MAC_OS_X_VERSION_MAX_ALLOWED >= 101200 as in 0001-sys.cpp-fix-for-macOS-use-numerical-constant-instead.patch.

[barracuda156]

In 4b2ad55a065d23b471b69e934d947a58ff3c3a3f/macports-ports (master):

libocca: update patch to fix clang builds on <10.12

See: #67259

[barracuda156]

In f541a01731ee1494297d2665dc1c25414cb1d480/macports-ports (master):

libocca: fix older Intel builds

Fixes: #67259