Add IAI_CALLGRIND_<triple>_VALGRIND_INCLUDE

[qRoC]

For cross compilation like CARGO_TARGET_<triple>_RUNNER.

Example:

IAI_CALLGRIND_X86_64_UNKNOWN_LINUX_GNU_VALGRIND_INCLUDE

[gamma0987]

Thanks for your interest in iai-callgrind!

Can you please explain a little bit more? What do you expect iai-callgrind to do when it encounters such a environment variable?

[qRoC]

Hi, from doc:

When building iai-callgrind with client requests, the valgrind header files must exist in your standard include path (most of the time /usr/include). This is usually the case if you've installed valgrind with your distribution's package manager. If not, you can point the IAI_CALLGRIND_VALGRIND_INCLUDE environment variable to the include path. So, if the headers can be found in /home/foo/repo/valgrind/{valgrind.h, callgrind.h, ...}, the correct include path would be IAI_CALLGRIND_VALGRIND_INCLUDE=/home/foo/repo (not /home/foo/repo/valgrind)

so for cross benches I must to set this variable every time, example:

IAI_CALLGRIND_VALGRIND_INCLUDE=/aarch64/valgrind/include cargo bench --target aarch64-unknown-linux-gnu

IAI_CALLGRIND_VALGRIND_INCLUDE=/x86_64/valgrind/include cargo bench --target x86_64-unknown-linux-gnu

My proposal:

1. Find IAI_CALLGRIND_<triple>_VALGRIND_INCLUDE variable
2. Find IAI_CALLGRIND_VALGRIND_INCLUDE
3. ...

This allows to set the path once per target:

IAI_CALLGRIND_AARCH64_UNKNOWN_LINUX_GNU_VALGRIND_INCLUDE=/aarch64/valgrind/include
IAI_CALLGRIND_X86_64_UNKNOWN_LINUX_GNU_VALGRIND_INCLUDE=/x86_64/valgrind/include

Then just run benches:

cargo bench --target aarch64-unknown-linux-gnu
cargo bench --target x86_64-unknown-linux-gnu

[qRoC]

Also, it would be nice if the reports were grouped by target (now - the comparison with the last launch, regardless of the target)

[gamma0987]

Thanks for clarifying. Sounds good. Regarding the grouping, you should already be able to achieve something like that by saving baselines per target. See the README https://github.com/iai-callgrind/iai-callgrind?tab=readme-ov-file#comparing-with-baselines.

[qRoC]

Regarding the grouping, you should already be able to achieve something like that by saving baselines per target.

I think this is a little different - there is no point in comparing two targets, moreover it looks terrible and is easy to make a mistake:

cargo bench --target aarch64-unknown-linux-gnu -- --save-baseline=aarch64_main
cargo bench --target aarch64-unknown-linux-gnu -- --save-baseline=aarch64_new
cargo bench --target x86_64-unknown-linux-gnu -- --save-baseline=x86_64_main
cargo bench --target x86_64-unknown-linux-gnu -- --save-baseline=x86_64_new

[gamma0987]

It's not the same and maybe not ideal for this usecase but for the time being there's a possibility to achieve a comparison between the same target and you're not completely lost. Maybe consider using just, a Makefile or a little script etc. to avoid the typing and typos? I'm going to have a look into it asap. I didn't have much time time to work on iai-callgrind lately.

[qRoC]

I didn't have much time time to work on iai-callgrind lately.

I was just interested to hear your opinion. This way I can do the PR when I have time.