ExternalProject: Move existing step scripts to separate subdirectory

This is in preparation for moving more inline content to separate
scripts as well. Having them in a separate subdirectory is consistent
with other modules and will make them easier to find and work with.

4 files changed, 490 insertions, 0 deletions

diff --git a/Modules/ExternalProject/RepositoryInfo.txt.in b/Modules/ExternalProject/RepositoryInfo.txt.in
new file mode 100644
index 0000000..df8e322
--- /dev/null
+++ b/Modules/ExternalProject/RepositoryInfo.txt.in
@@ -0,0 +1,3 @@
+repository='@repository@'
+module='@module@'
+tag='@tag@'
diff --git a/Modules/ExternalProject/download.cmake.in b/Modules/ExternalProject/download.cmake.in
new file mode 100644
index 0000000..ff8c659
--- /dev/null
+++ b/Modules/ExternalProject/download.cmake.in
@@ -0,0 +1,173 @@
+# 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(check_file_hash has_hash hash_is_good)
+  if("${has_hash}" STREQUAL "")
+    message(FATAL_ERROR "has_hash Can't be empty")
+  endif()
+
+  if("${hash_is_good}" STREQUAL "")
+    message(FATAL_ERROR "hash_is_good Can't be empty")
+  endif()
+
+  if("@ALGO@" STREQUAL "")
+    # No check
+    set("${has_hash}" FALSE PARENT_SCOPE)
+    set("${hash_is_good}" FALSE PARENT_SCOPE)
+    return()
+  endif()
+
+  set("${has_hash}" TRUE PARENT_SCOPE)
+
+  message(STATUS "verifying file...
+       file='@LOCAL@'")
+
+  file("@ALGO@" "@LOCAL@" actual_value)
+
+  if(NOT "${actual_value}" STREQUAL "@EXPECT_VALUE@")
+    set("${hash_is_good}" FALSE PARENT_SCOPE)
+    message(STATUS "@ALGO@ hash of
+    @LOCAL@
+  does not match expected value
+    expected: '@EXPECT_VALUE@'
+      actual: '${actual_value}'")
+  else()
+    set("${hash_is_good}" TRUE PARENT_SCOPE)
+  endif()
+endfunction()
+
+function(sleep_before_download attempt)
+  if(attempt EQUAL 0)
+    return()
+  endif()
+
+  if(attempt EQUAL 1)
+    message(STATUS "Retrying...")
+    return()
+  endif()
+
+  set(sleep_seconds 0)
+
+  if(attempt EQUAL 2)
+    set(sleep_seconds 5)
+  elseif(attempt EQUAL 3)
+    set(sleep_seconds 5)
+  elseif(attempt EQUAL 4)
+    set(sleep_seconds 15)
+  elseif(attempt EQUAL 5)
+    set(sleep_seconds 60)
+  elseif(attempt EQUAL 6)
+    set(sleep_seconds 90)
+  elseif(attempt EQUAL 7)
+    set(sleep_seconds 300)
+  else()
+    set(sleep_seconds 1200)
+  endif()
+
+  message(STATUS "Retry after ${sleep_seconds} seconds (attempt #${attempt}) ...")
+
+  execute_process(COMMAND "${CMAKE_COMMAND}" -E sleep "${sleep_seconds}")
+endfunction()
+
+if("@LOCAL@" STREQUAL "")
+  message(FATAL_ERROR "LOCAL can't be empty")
+endif()
+
+if("@REMOTE@" STREQUAL "")
+  message(FATAL_ERROR "REMOTE can't be empty")
+endif()
+
+if(EXISTS "@LOCAL@")
+  check_file_hash(has_hash hash_is_good)
+  if(has_hash)
+    if(hash_is_good)
+      message(STATUS "File already exists and hash match (skip download):
+  file='@LOCAL@'
+  @ALGO@='@EXPECT_VALUE@'"
+      )
+      return()
+    else()
+      message(STATUS "File already exists but hash mismatch. Removing...")
+      file(REMOVE "@LOCAL@")
+    endif()
+  else()
+    message(STATUS "File already exists but no hash specified (use URL_HASH):
+  file='@LOCAL@'
+Old file will be removed and new file downloaded from URL."
+    )
+    file(REMOVE "@LOCAL@")
+  endif()
+endif()
+
+set(retry_number 5)
+
+message(STATUS "Downloading...
+   dst='@LOCAL@'
+   timeout='@TIMEOUT_MSG@'
+   inactivity timeout='@INACTIVITY_TIMEOUT_MSG@'"
+)
+set(download_retry_codes 7 6 8 15)
+set(skip_url_list)
+set(status_code)
+foreach(i RANGE ${retry_number})
+  if(status_code IN_LIST download_retry_codes)
+    sleep_before_download(${i})
+  endif()
+  foreach(url @REMOTE@)
+    if(NOT url IN_LIST skip_url_list)
+      message(STATUS "Using src='${url}'")
+
+      @TLS_VERIFY_CODE@
+      @TLS_CAINFO_CODE@
+      @NETRC_CODE@
+      @NETRC_FILE_CODE@
+
+      file(
+        DOWNLOAD
+        "${url}" "@LOCAL@"
+        @SHOW_PROGRESS@
+        @TIMEOUT_ARGS@
+        @INACTIVITY_TIMEOUT_ARGS@
+        STATUS status
+        LOG log
+        @USERPWD_ARGS@
+        @HTTP_HEADERS_ARGS@
+        )
+
+      list(GET status 0 status_code)
+      list(GET status 1 status_string)
+
+      if(status_code EQUAL 0)
+        check_file_hash(has_hash hash_is_good)
+        if(has_hash AND NOT hash_is_good)
+          message(STATUS "Hash mismatch, removing...")
+          file(REMOVE "@LOCAL@")
+        else()
+          message(STATUS "Downloading... done")
+          return()
+        endif()
+      else()
+        string(APPEND logFailedURLs "error: downloading '${url}' failed
+        status_code: ${status_code}
+        status_string: ${status_string}
+        log:
+        --- LOG BEGIN ---
+        ${log}
+        --- LOG END ---
+        "
+        )
+      if(NOT status_code IN_LIST download_retry_codes)
+        list(APPEND skip_url_list "${url}")
+        break()
+      endif()
+    endif()
+  endif()
+  endforeach()
+endforeach()
+
+message(FATAL_ERROR "Each download failed!
+  ${logFailedURLs}
+  "
+)
diff --git a/Modules/ExternalProject/gitupdate.cmake.in b/Modules/ExternalProject/gitupdate.cmake.in
new file mode 100644
index 0000000..0de2372
--- /dev/null
+++ b/Modules/ExternalProject/gitupdate.cmake.in
@@ -0,0 +1,277 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+cmake_minimum_required(VERSION 3.5)
+
+function(get_hash_for_ref ref out_var err_var)
+  execute_process(
+    COMMAND "@git_EXECUTABLE@" rev-parse "${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 ${head_sha}
+        WORKING_DIRECTORY "@work_dir@"
+      )
+      execute_process(
+        COMMAND "@git_EXECUTABLE@" stash pop --index --quiet
+        WORKING_DIRECTORY "@work_dir@"
+      )
+      message(FATAL_ERROR "\nFailed to unstash changes in: '@work_dir@'."
+                          "\nYou will have to resolve the conflicts manually")
+    endif()
+  endif()
+endif()
+
+set(init_submodules "@init_submodules@")
+if(init_submodules)
+  execute_process(
+    COMMAND "@git_EXECUTABLE@" submodule update @git_submodules_recurse@ --init @git_submodules@
+    WORKING_DIRECTORY "@work_dir@"
+    COMMAND_ERROR_IS_FATAL ANY
+  )
+endif()
diff --git a/Modules/ExternalProject/verify.cmake.in b/Modules/ExternalProject/verify.cmake.in
new file mode 100644
index 0000000..c06da4e
--- /dev/null
+++ b/Modules/ExternalProject/verify.cmake.in
@@ -0,0 +1,37 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+cmake_minimum_required(VERSION 3.5)
+
+if("@LOCAL@" STREQUAL "")
+  message(FATAL_ERROR "LOCAL can't be empty")
+endif()
+
+if(NOT EXISTS "@LOCAL@")
+  message(FATAL_ERROR "File not found: @LOCAL@")
+endif()
+
+if("@ALGO@" STREQUAL "")
+  message(WARNING "File will not be verified since no URL_HASH specified")
+  return()
+endif()
+
+if("@EXPECT_VALUE@" STREQUAL "")
+  message(FATAL_ERROR "EXPECT_VALUE can't be empty")
+endif()
+
+message(STATUS "verifying file...
+     file='@LOCAL@'")
+
+file("@ALGO@" "@LOCAL@" actual_value)
+
+if(NOT "${actual_value}" STREQUAL "@EXPECT_VALUE@")
+  message(FATAL_ERROR "error: @ALGO@ hash of
+  @LOCAL@
+does not match expected value
+  expected: '@EXPECT_VALUE@'
+    actual: '${actual_value}'
+")
+endif()
+
+message(STATUS "verifying file... done")