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Diffstat (limited to 'Modules/ExternalProject/gitupdate.cmake.in')
| -rw-r--r-- | Modules/ExternalProject/gitupdate.cmake.in | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/Modules/ExternalProject/gitupdate.cmake.in b/Modules/ExternalProject/gitupdate.cmake.in new file mode 100644 index 0000000..0de2372 --- /dev/null +++ b/Modules/ExternalProject/gitupdate.cmake.in @@ -0,0 +1,277 @@ +# Distributed under the OSI-approved BSD 3-Clause License. See accompanying +# file Copyright.txt or https://cmake.org/licensing for details. + +cmake_minimum_required(VERSION 3.5) + +function(get_hash_for_ref ref out_var err_var) + execute_process( + COMMAND "@git_EXECUTABLE@" rev-parse "${ref}^0" + WORKING_DIRECTORY "@work_dir@" + RESULT_VARIABLE error_code + OUTPUT_VARIABLE ref_hash + ERROR_VARIABLE error_msg + OUTPUT_STRIP_TRAILING_WHITESPACE + ) + if(error_code) + set(${out_var} "" PARENT_SCOPE) + else() + set(${out_var} "${ref_hash}" PARENT_SCOPE) + endif() + set(${err_var} "${error_msg}" PARENT_SCOPE) +endfunction() + +get_hash_for_ref(HEAD head_sha error_msg) +if(head_sha STREQUAL "") + message(FATAL_ERROR "Failed to get the hash for HEAD:\n${error_msg}") +endif() + + +execute_process( + COMMAND "@git_EXECUTABLE@" show-ref "@git_tag@" + WORKING_DIRECTORY "@work_dir@" + OUTPUT_VARIABLE show_ref_output +) +if(show_ref_output MATCHES "^[a-z0-9]+[ \\t]+refs/remotes/") + # Given a full remote/branch-name and we know about it already. Since + # branches can move around, we always have to fetch. + set(fetch_required YES) + set(checkout_name "@git_tag@") + +elseif(show_ref_output MATCHES "^[a-z0-9]+[ \\t]+refs/tags/") + # Given a tag name that we already know about. We don't know if the tag we + # have matches the remote though (tags can move), so we should fetch. + set(fetch_required YES) + set(checkout_name "@git_tag@") + + # Special case to preserve backward compatibility: if we are already at the + # same commit as the tag we hold locally, don't do a fetch and assume the tag + # hasn't moved on the remote. + # FIXME: We should provide an option to always fetch for this case + get_hash_for_ref("@git_tag@" tag_sha error_msg) + if(tag_sha STREQUAL head_sha) + message(VERBOSE "Already at requested tag: ${tag_sha}") + return() + endif() + +elseif(show_ref_output MATCHES "^[a-z0-9]+[ \\t]+refs/heads/") + # Given a branch name without any remote and we already have a branch by that + # name. We might already have that branch checked out or it might be a + # different branch. It isn't safe to use a bare branch name without the + # remote, so do a fetch and replace the ref with one that includes the remote. + set(fetch_required YES) + set(checkout_name "@git_remote_name@/@git_tag@") + +else() + get_hash_for_ref("@git_tag@" tag_sha error_msg) + if(tag_sha STREQUAL head_sha) + # Have the right commit checked out already + message(VERBOSE "Already at requested ref: ${tag_sha}") + return() + + elseif(tag_sha STREQUAL "") + # We don't know about this ref yet, so we have no choice but to fetch. + # We deliberately swallow any error message at the default log level + # because it can be confusing for users to see a failed git command. + # That failure is being handled here, so it isn't an error. + set(fetch_required YES) + set(checkout_name "@git_tag@") + if(NOT error_msg STREQUAL "") + message(VERBOSE "${error_msg}") + endif() + + else() + # We have the commit, so we know we were asked to find a commit hash + # (otherwise it would have been handled further above), but we don't + # have that commit checked out yet + set(fetch_required NO) + set(checkout_name "@git_tag@") + if(NOT error_msg STREQUAL "") + message(WARNING "${error_msg}") + endif() + + endif() +endif() + +if(fetch_required) + message(VERBOSE "Fetching latest from the remote @git_remote_name@") + execute_process( + COMMAND "@git_EXECUTABLE@" fetch --tags --force "@git_remote_name@" + WORKING_DIRECTORY "@work_dir@" + COMMAND_ERROR_IS_FATAL ANY + ) +endif() + +set(git_update_strategy "@git_update_strategy@") +if(git_update_strategy STREQUAL "") + # Backward compatibility requires REBASE as the default behavior + set(git_update_strategy REBASE) +endif() + +if(git_update_strategy MATCHES "^REBASE(_CHECKOUT)?$") + # Asked to potentially try to rebase first, maybe with fallback to checkout. + # We can't if we aren't already on a branch and we shouldn't if that local + # branch isn't tracking the one we want to checkout. + execute_process( + COMMAND "@git_EXECUTABLE@" symbolic-ref -q HEAD + WORKING_DIRECTORY "@work_dir@" + OUTPUT_VARIABLE current_branch + OUTPUT_STRIP_TRAILING_WHITESPACE + # Don't test for an error. If this isn't a branch, we get a non-zero error + # code but empty output. + ) + + if(current_branch STREQUAL "") + # Not on a branch, checkout is the only sensible option since any rebase + # would always fail (and backward compatibility requires us to checkout in + # this situation) + set(git_update_strategy CHECKOUT) + + else() + execute_process( + COMMAND "@git_EXECUTABLE@" for-each-ref "--format='%(upstream:short)'" "${current_branch}" + WORKING_DIRECTORY "@work_dir@" + OUTPUT_VARIABLE upstream_branch + OUTPUT_STRIP_TRAILING_WHITESPACE + COMMAND_ERROR_IS_FATAL ANY # There is no error if no upstream is set + ) + if(NOT upstream_branch STREQUAL checkout_name) + # Not safe to rebase when asked to checkout a different branch to the one + # we are tracking. If we did rebase, we could end up with arbitrary + # commits added to the ref we were asked to checkout if the current local + # branch happens to be able to rebase onto the target branch. There would + # be no error message and the user wouldn't know this was occurring. + set(git_update_strategy CHECKOUT) + endif() + + endif() +elseif(NOT git_update_strategy STREQUAL "CHECKOUT") + message(FATAL_ERROR "Unsupported git update strategy: ${git_update_strategy}") +endif() + + +# Check if stash is needed +execute_process( + COMMAND "@git_EXECUTABLE@" status --porcelain + WORKING_DIRECTORY "@work_dir@" + RESULT_VARIABLE error_code + OUTPUT_VARIABLE repo_status +) +if(error_code) + message(FATAL_ERROR "Failed to get the status") +endif() +string(LENGTH "${repo_status}" need_stash) + +# If not in clean state, stash changes in order to be able to perform a +# rebase or checkout without losing those changes permanently +if(need_stash) + execute_process( + COMMAND "@git_EXECUTABLE@" stash save @git_stash_save_options@ + WORKING_DIRECTORY "@work_dir@" + COMMAND_ERROR_IS_FATAL ANY + ) +endif() + +if(git_update_strategy STREQUAL "CHECKOUT") + execute_process( + COMMAND "@git_EXECUTABLE@" checkout "${checkout_name}" + WORKING_DIRECTORY "@work_dir@" + COMMAND_ERROR_IS_FATAL ANY + ) +else() + execute_process( + COMMAND "@git_EXECUTABLE@" rebase "${checkout_name}" + WORKING_DIRECTORY "@work_dir@" + RESULT_VARIABLE error_code + OUTPUT_VARIABLE rebase_output + ERROR_VARIABLE rebase_output + ) + if(error_code) + # Rebase failed, undo the rebase attempt before continuing + execute_process( + COMMAND "@git_EXECUTABLE@" rebase --abort + WORKING_DIRECTORY "@work_dir@" + ) + + if(NOT git_update_strategy STREQUAL "REBASE_CHECKOUT") + # Not allowed to do a checkout as a fallback, so cannot proceed + if(need_stash) + execute_process( + COMMAND "@git_EXECUTABLE@" stash pop --index --quiet + WORKING_DIRECTORY "@work_dir@" + ) + endif() + message(FATAL_ERROR "\nFailed to rebase in: '@work_dir@'." + "\nOutput from the attempted rebase follows:" + "\n${rebase_output}" + "\n\nYou will have to resolve the conflicts manually") + endif() + + # Fall back to checkout. We create an annotated tag so that the user + # can manually inspect the situation and revert if required. + # We can't log the failed rebase output because MSVC sees it and + # intervenes, causing the build to fail even though it completes. + # Write it to a file instead. + string(TIMESTAMP tag_timestamp "%Y%m%dT%H%M%S" UTC) + set(tag_name _cmake_ExternalProject_moved_from_here_${tag_timestamp}Z) + set(error_log_file ${CMAKE_CURRENT_LIST_DIR}/rebase_error_${tag_timestamp}Z.log) + file(WRITE ${error_log_file} "${rebase_output}") + message(WARNING "Rebase failed, output has been saved to ${error_log_file}" + "\nFalling back to checkout, previous commit tagged as ${tag_name}") + execute_process( + COMMAND "@git_EXECUTABLE@" tag -a + -m "ExternalProject attempting to move from here to ${checkout_name}" + ${tag_name} + WORKING_DIRECTORY "@work_dir@" + COMMAND_ERROR_IS_FATAL ANY + ) + + execute_process( + COMMAND "@git_EXECUTABLE@" checkout "${checkout_name}" + WORKING_DIRECTORY "@work_dir@" + COMMAND_ERROR_IS_FATAL ANY + ) + endif() +endif() + +if(need_stash) + # Put back the stashed changes + execute_process( + COMMAND "@git_EXECUTABLE@" stash pop --index --quiet + WORKING_DIRECTORY "@work_dir@" + RESULT_VARIABLE error_code + ) + if(error_code) + # Stash pop --index failed: Try again dropping the index + execute_process( + COMMAND "@git_EXECUTABLE@" reset --hard --quiet + WORKING_DIRECTORY "@work_dir@" + ) + execute_process( + COMMAND "@git_EXECUTABLE@" stash pop --quiet + WORKING_DIRECTORY "@work_dir@" + RESULT_VARIABLE error_code + ) + if(error_code) + # Stash pop failed: Restore previous state. + execute_process( + COMMAND "@git_EXECUTABLE@" reset --hard --quiet ${head_sha} + WORKING_DIRECTORY "@work_dir@" + ) + execute_process( + COMMAND "@git_EXECUTABLE@" stash pop --index --quiet + WORKING_DIRECTORY "@work_dir@" + ) + message(FATAL_ERROR "\nFailed to unstash changes in: '@work_dir@'." + "\nYou will have to resolve the conflicts manually") + endif() + endif() +endif() + +set(init_submodules "@init_submodules@") +if(init_submodules) + execute_process( + COMMAND "@git_EXECUTABLE@" submodule update @git_submodules_recurse@ --init @git_submodules@ + WORKING_DIRECTORY "@work_dir@" + COMMAND_ERROR_IS_FATAL ANY + ) +endif() |