In 5e941a545b (ExternalProject: Ensure git fetch if updating to hash we
don't have yet, 2021-05-09), the form ${ref}^{commit} was used to ensure
the ref was treated as a commit. When running under a MSYS2 or
Cygwin shell, the {commit} part can be translated by the shell, leaving it as
${ref}^commit, which git doesn't understand. Use the equivalent but
safer form ${ref}^0, since it won't be subject to the shell substitution
issue.
Fixes: #22299
In ac6a4d4884 (ExternalProject: Improve robustness of update step,
2020-10-17), the method used to check whether we already have a
commit or not was changed from using git rev-list to git rev-parse.
The new logic assumed rev-parse would output nothing if given a commit
hash it didn't know about, but it simply prints the hash again without
raising an error in this scenario. Amend that logic by adding ^{commit} to
the ref to ensure we do get an error if that ref is not currently known.
Fixes: #22166
Refactoring of the ExternalProject and FetchContent modules moved
the commands into CMake scripts. This broke custom commands that
used shell redirection or special build tool variables of the form
$(MakeVar). Undo the sequence of commits that performed this
refactoring and follow-up fixes associated with it.
The following commits are reverted by this change:
4f3d1abbb4 (ExternalProject: Refactor pre-configure steps to support
no-target uses, 2021-02-05)
17e5516e60 (FetchContent: Invoke steps directly and avoid a separate
sub-build, 2021-01-29)
bd876f3849 (FetchContent: Restore patch command support,
2021-02-18)
404cddb7bb (ExternalProject: Fix misuse of IS_NEWER_THAN in
timestamp checks, 2021-02-21)
b0da671243 (FetchContent: Don't update timestamps if files don't
change, 2021-02-18)
Fixes: #21892
The mkdir, download, update and patch steps are used by
FetchContent during the configure phase of the main build. Because
these steps need a target, this has so far required a sub-build to be
set up. The changes here factor out the preparation of the scripts
from the creation of the targets, allowing future work to leverage these
steps without a sub-build (see #21703).
As part of the refactoring, some rationalisation of the stamp files,
repository info files and script names was done to make things more
consistent between download methods and step implementations.
Every download method now records its own specific repository info
in a file and that file is a dependency of the download step. The source
directory is also written to that file, so if the SOURCE_DIR changes, the
download will be retriggered (the existing implementation fails in this
scenario). Each download method now also has just one driver script
that implements the whole step (it may pull in other scripts to do its
task though). The patch step gained support for USES_TERMINAL as
a result of generalising the implementation for custom commands.
Fixes: #21748
Refactor the update logic to make it easier to follow. The following
fixes/improvements are some consequences of this change:
* Absorb a confusing git checkout failure message when the failure
is allowed and we act on that failure appropriately.
* Fix an unnecessary fetch in some scenarios when checking out a
git hash we already have locally.
* Stash and restore any local changes even when not rebasing.
* Avoid unsafe rebasing where we are not on a branch that is
already tracking the requested branch.
* When fetching, use --tags --force to ensure we get all the tags
and commits leading up to them regardless of whether the tags
are on branches or not. Also update our local tags if they move
on the remote.
Fixes: #20677
Commit 0aea435aa1 (ExternalProject: Provide choice of
git update strategies, 2020-02-12) added the git update
strategies, but the CHECKOUT strategy was not handling
remote refs correctly. The local ref would be checked out
instead and no warning or error would have been emitted.
The test that should have caught this was also malformed
and did not actually move the local master branch as intended.
The refactoring exposed that the original implementation
was referring to an undefined variable src_name, which was
previously only used in error messages. This has been fixed
as part of the refactoring work.
Fixes: #20336
