Correct current script dir detection for GCC

[franksinankaya]

Current path detection was fixed in clang script but skipped in gcc. Copy and paste the solution.

[franksinankaya]

@am11 @jkotas @janvorli

[franksinankaya]

@dotnet-bot retest Ubuntu x64 Checked CoreFX Tests
@dotnet-bot retest Ubuntu x64 Checked Innerloop Build and Test

[franksinankaya]

Time to check in?

[janvorli]

I still keep thinking why the gen-buildsys-gcc.sh should not be a bash script. All of our other scripts are bash ones and so just one of them being more general shell script doesn't seem to be beneficial. And if that script was bash too, we could leave the script path extraction as it was in the clang script and would not have to pass it as an extra argument.

[franksinankaya]

I think the platform where @am11 is planning to use gcc doesn't have bash. He made me remove it during code review.

[janvorli]

I think the platform where @am11 is planning to use gcc doesn't have bash

The build.sh and other scripts we use are bash, so it seems unnecessary to have just one script more general when it is sourced from a bash one anyways.

[franksinankaya]

@am11: looking at you for the full story.

Are we trying to make shellcheck happy or is there a real reason behind no-BASHism?

[am11]

At the point when it was added, there was no bash specific feature being used, so I proposed this change so to use the dependencies sparingly. Now that we have this file being sourced, if we need to resolve ScriptPath using BASH[] variable, we can change line#1 in gcc file from sh to bash. However, if we can avoid it, that would be better. Other platforms also keep their build script POSIX compatible, as well as the scripts they ship with products for runtime; to keep them dependency-free and portable by design.

I started with by conveting all (58) *.sh in repo, mostly it is straightforward and some cases, such as build-test.sh, require bit of a refctoring around the usage of arrays. The idea was to provide a 1:1 drop-in POSIX script replacement. This is to remove dependency from build and run times. Mainly the Bash specific feature used in dotnet repos is array, which could be extracted out as few helper functions (http://www.etalabs.net/sh_tricks.html).

[franksinankaya]

I can keep this version since it does work.

[franksinankaya]

@dotnet-bot retest coreclr-ci
@dotnet-bot retest coreclr-ci (Build Linux arm64 debug)
@dotnet-bot retest coreclr-ci (Build Linux_musl arm64 checked)

[janvorli]

Ok, let's keep the gen-buildsys-gcc.sh as universal shell script.

[franksinankaya]

@dotnet-bot test CentOS7.1 x64 Checked Innerloop Build and Test please

[franksinankaya]

I think we have beaten this change enough.

[janvorli]

LGTM, thank you!