[llvm-dev] FW: How to use -forder-file-instrumentation to generate order file for iOS Apps?

[Jack Chen via llvm-dev]

Hi Manman,

I tried again using XCode directly (previously I built the binary on linux,
and then downloaded the binary to the iOS simulator for execution), and it
works for me now.
Thank you so much for your help!

The new instrumentation looks interesting. I will look at that too.
Thanks again!

Regards,
Jack

On Sat, Sep 25, 2021 at 4:13 AM Manman Ren <manman.ren at gmail.com> wrote:

> We mainly use this for iOS, simulator should work and it should work for
> ObjectiveC and Swift.
> I don't think we need *-fprofile-instr-generate.*
>
> We are experimenting with a new instrumentation:
> https://lists.llvm.org/pipermail/llvm-dev/2021-June/151086.html in case
> you are interested.
> + Ellis
>
> Manman
>
> On Fri, Sep 24, 2021 at 3:12 AM Jack Chen <jacklcc at google.com> wrote:
>
>> Thank you Manman!
>>
>> I did try the feature with a C file and it worked well. I
>> called __llvm_profile_set_filename() and __llvm_orderfile_dump() in the C
>> file, built it with the flags, and ran the binary on Linux. After running,
>> a profraw.order file was generated with correct contents.
>>
>> However, I wasn't able to make it work for my iOS app - the profraw.order
>> file is indeed generated, but it doesn't contain valid contents.
>>
>> The major differences between them are: (1) the iOS app is written in
>> objective c and swift, as opposed to C and (2)  The iOS app was run on iOS
>> simulator, and the profraw.order data was collected on iOS simulator, as
>> opposed to on linux.
>>
>> I wonder if you know what could be wrong? Maybe this feature isn't
>> supported by objective c and swift, or perhaps it doesn't work on the iOS
>> platform?
>>
>> Thanks again! Really appreciate your help!
>>
>> Regards,
>> Jack
>>
>>
>> On Fri, Sep 24, 2021 at 5:48 AM Manman Ren <manman.ren at gmail.com> wrote:
>>
>>> I don't think I wrote a doc on this.
>>> 'compiler-rt/test/profile/instrprof-order-file.test' shows how to use it,
>>> build the app with -forder-file-instrumentation and -mllvm
>>> -orderfile-write-mapping, then run the app, use the mapping file to decode
>>> the profile.
>>>
>>> The profile should be in default.profraw.order. But you can change its
>>> name via:
>>>
>>> - Writes to the file with the last name given to \a *
>>> - __llvm_profile_set_filename(),
>>> - or if it hasn't been called, the \c LLVM_PROFILE_FILE environment
>>> variable,
>>> - or if that's not set, the last name set to INSTR_PROF_PROFILE_NAME_VAR,
>>> - or if that's not set,  \c "default.profraw".
>>>
>>> Hope this helps!
>>> Manman
>>>
>>> On Thu, Sep 23, 2021 at 2:45 PM Manman Ren <mren at fb.com> wrote:
>>>
>>>>
>>>>
>>>>
>>>>
>>>> *From: *Manman Ren <mren at fb.com>
>>>> *Date: *Thursday, September 23, 2021 at 2:20 PM
>>>> *To: *Jack Chen <jacklcc at google.com>, llvm-dev at lists.llvm.org <
>>>> llvm-dev at lists.llvm.org>
>>>> *Subject: *Re: How to use -forder-file-instrumentation to generate
>>>> order file for iOS Apps?
>>>>
>>>> I don't think I wrote a doc on this.
>>>> 'compiler-rt/test/profile/instrprof-order-file.test' shows how to use it,
>>>> build the app with -forder-file-instrumentation and -mllvm
>>>> -orderfile-write-mapping, then run the app, use the mapping file to decode
>>>> the profile.
>>>>
>>>> The profile should be in default.profraw.order. But you can change its
>>>> name via:
>>>>
>>>> - Writes to the file with the last name given to \a *
>>>> - __llvm_profile_set_filename(),
>>>> - or if it hasn't been called, the \c LLVM_PROFILE_FILE environment
>>>> variable,
>>>> - or if that's not set, the last name set to
>>>> INSTR_PROF_PROFILE_NAME_VAR,
>>>> - or if that's not set,  \c "default.profraw".
>>>>
>>>> Hope this helps!
>>>> Manman
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> *From: *Jack Chen <jacklcc at google.com>
>>>> *Date: *Thursday, September 23, 2021 at 1:05 AM
>>>> *To: *llvm-dev at lists.llvm.org <llvm-dev at lists.llvm.org>
>>>> *Cc: *Manman Ren <mren at fb.com>
>>>> *Subject: *How to use -forder-file-instrumentation to generate order
>>>> file for iOS Apps?
>>>>
>>>> Hello llvm developers,
>>>>
>>>>
>>>>
>>>> I wonder how to use the flag *-forder-file-instrumentation* for iOS
>>>> Apps written in objective-C and swift?
>>>>
>>>>
>>>>
>>>> I enabled the flags* -forder-file-instrumentation -mllvm
>>>> -orderfile-write-mapping* *-fprofile-instr-generate *when building my
>>>> iOS App, which is written in objective-C and swift.
>>>>
>>>> After running the App on the iOS simulator on my macbook, a
>>>> profraw.order file is generated in the simulator's folder. However,
>>>> the file doesn't contain the correct contents. It contains too few bytes,
>>>> also most data blobs are 32 bits (I believe the right format is 64-bits
>>>> MD5), and many of them are duplicated. FWIW, here are the first few bytes:
>>>>
>>>> 00000000: 70aa cb11 0100 0000 f8ac cb11 0100 0000  p...............
>>>>
>>>> 00000010: 90ab cb11 0100 0000 58aa cb11 0100 0000  ........X.......
>>>>
>>>> 00000020: ffff ffff 0000 0000 0000 0000 0000 0000  ................
>>>>
>>>> 00000030: 0000 0000 0000 0000 ffff ffff 0000 0000  ................
>>>>
>>>> 00000040: 0000 0000 0000 0000 0000 0000 0000 0000  ................
>>>>
>>>> 00000050: 0000 0000 0000 0000 0000 0000 0000 0000  ................
>>>>
>>>> 00000060: 0000 0000 0000 0000 0000 0000 0000 0000  ................
>>>>
>>>> 00000070: 0000 0000 0000 0000 0000 0000 0000 0000  ................
>>>>
>>>> 00000080: 0000 0000 0000 0000 0000 0000 0000 0000  ................
>>>>
>>>> I wonder if the feature *-forder-file-instrumentation *is supported
>>>> for iOS Apps that are written in objective-C and swift?
>>>>
>>>> If yes, then I wonder what's the proper steps to use it?
>>>>
>>>>
>>>>
>>>> Thank you very much for your time.
>>>>
>>>>
>>>>
>>>> Regards,
>>>>
>>>> Jack
>>>>
>>>>
>>>>
>>>
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