For Apple silicon, use machdep.cpu.brand_string in preference to decoding hw.machine

[dlenski]

This functionality was implemented in #65 ("Updated package.name to also query machdep.cpu.brand_string if decode of hw.machine fails"), but then it was omitted from the subsequent #100, probably inadvertently.

Adding that functionality back here, so that the package/device name can be shown correctly on recent devices and macOS/iOS versions. I have reversed the order so that machdep.cpu.brand_string is checked before attempting
to decode hw.machine, since the former appears to be more future-proof.

Before this change, on a recent MacBook Pro:

$ cpu-info
...
Debug (cpuinfo): hw.machine: arm64
Warning in cpuinfo: parsing "hw.machine" failed: Undefined error: 0
...
Packages:
    0:

After this change:

$ cpu-info
...
Debug (cpuinfo): machdep.cpu.brand_string: Apple M2 Pro
...
Packages:
    0: Apple M2 Pro

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[dlenski]

The logic in decode_package_name_from_hw_machine has already become somewhat obsolete, which is why it makes sense to prefer read_package_name_from_brand_string wherever it succeeds on newer devices/OSes.

For example, the package in iPhone 15 Pro should be described as Apple A17 Pro, rather than simply A17 (which is what the current logic would show, according to the hw.machine values shown at: https://gist.github.com/adamawolf/3048717#file-apple_mobile_device_types-txt-L55-L56).

[dlenski]

This PR does exactly what it says it does, but it has not received any review or comments for ~6 months.

I see that @gonnet has recently merged a PR for Apple/Mach (973ec72). Perhaps he could review this one as well? 😃

[dlenski]

I fixed the clang-format violation from d8d9389 in 04efc5e (diff):

diff --git a/src/arm/mach/init.c b/src/arm/mach/init.c
index b37b6bb..c4e6521 100644
--- a/src/arm/mach/init.c
+++ b/src/arm/mach/init.c
@@ -109,7 +109,7 @@ static int read_package_name_from_brand_string(char* package_name) {
                return false;
        }

-       char *brand_string = alloca(size);
+       char* brand_string = alloca(size);
        if (sysctlbyname("machdep.cpu.brand_string", brand_string, &size, NULL, 0) != 0)
                goto sysctlfail;
        cpuinfo_log_debug("machdep.cpu.brand_string: %s", brand_string);

@malfet, @gonnet, could whoever trigger the PR workflows please retrigger it? 😅

[F0bes]

Hi there. I come from @PCSX2 and we depend on this library.
In hopes that this gets some attention, and so we can avoid manually patching the dependency, I just wanted to say that I've applied this patch locally and it works as expected. I'm using an Apple Mac Mini M4 Pro.
Thanks :)

[digantdesai]

Thanks. LGTM. Sorry for the delay.