Pipeline: Get SCM changes for build

[Sverre Moe]

The following will get me the top most git commit hash:

def gitCommit = sh(returnStdout: true, script: 'git rev-parse HEAD').trim()

The following will get me the top most git commit message:

def gitCommitMessage = sh(returnStdout: true, script: 'git log -n 1 --format=%s').trim()

However within one single build there is n number of commits. I need all commits listed on Changes.

Is there an environment parameter that would get me all the changes, or at least the number of changes to use in git log?