[llvm] Improve export.sh with help and snapshot

This change adds the ability to create source tarballs for unreleased or untagged code by providing the `--git-ref <GIT_REF>` flag to the `llvm/utils/release/export.sh` script. This is useful for creating daily snapshot tarballs that can easily be consumed by packagers who want to build a daily snapshot.

The default behavior of `export.sh` hasn't changed.

You may also provide a `--template` argument to say how the artifacts
are supposed to be named (as suggested by @hans).

The `-help` output of `export.sh` was changed quite significantly to look like this:

```
Export the Git sources and build tarballs from them.

Usage: export.sh [-release|--release <major>.<minor>.<patch>]
                      [-rc|--rc <num>]
                      [-final|--final]
                      [-git-ref|--git-ref <git-ref>]
                      [-template|--template <template>]

Flags:

  -release  | --release <major>.<minor>.<patch>    The version number of the release
  -rc       | --rc <num>                           The release candidate number
  -final    | --final                              When provided, this option will disable the rc flag
  -git-ref  | --git-ref <git-ref>                  (optional) Use <git-ref> to determine the release and don't export the test-suite files
  -template | --template <template>                (optional) Possible placeholders: $PROJECT $YYYYMMDD $GIT_REF $RELEASE $RC.
                                                   Defaults to '${PROJECT}-${RELEASE}${RC}.src.tar.xz'.

The following list shows the filenames (with <placeholders>) for the artifacts
that are being generated (given that you don't touch --template).

  * llvm-<RELEASE><RC>.src.tar.xz
  * clang-<RELEASE><RC>.src.tar.xz
  * compiler-rt-<RELEASE><RC>.src.tar.xz
  * libcxx-<RELEASE><RC>.src.tar.xz
  * libcxxabi-<RELEASE><RC>.src.tar.xz
  * libclc-<RELEASE><RC>.src.tar.xz
  * clang-tools-extra-<RELEASE><RC>.src.tar.xz
  * polly-<RELEASE><RC>.src.tar.xz
  * lldb-<RELEASE><RC>.src.tar.xz
  * lld-<RELEASE><RC>.src.tar.xz
  * openmp-<RELEASE><RC>.src.tar.xz
  * libunwind-<RELEASE><RC>.src.tar.xz
  * flang-<RELEASE><RC>.src.tar.xz

Additional files being generated:

  * llvm-project-<RELEASE><RC>.src.tar.xz    (the complete LLVM source project)
  * test-suite-<RELEASE><RC>.src.tar.xz      (only when not using --git-ref)

To ease the creation of snapshot builds, we also provide these files

  * llvm-release-<YYYYMMDD>.txt        (contains the <RELEASE> as a text)
  * llvm-rc-<YYYYMMDD>.txt             (contains the rc version passed to the invocation of export.sh)
  * llvm-git-revision-<YYYYMMDD>.txt   (contains the current git revision sha1)

Example values for the placeholders:

  * <RELEASE>  -> 13.0.0
  * <YYYYMMDD> -> 20210414
  * <RC>       -> rc4        (will be empty when using --git-ref)

In order to generate snapshots of the upstream main branch you could do this for example:

  export.sh --git-ref upstream/main --template '${PROJECT}-${YYYYMMDD}.src.tar.xz'

```

Reviewed By: tstellar

Differential Revision: https://reviews.llvm.org/D101446

0 files changed, 0 insertions, 0 deletions