init-repository: add --depth argument

There are cases when someone may only want to do a shallow clone, e.g.
in CI scenarios.
Adding a --depth argument to reflect to allow shallow clones of the
(sub)modules.

Change-Id: Ia57f6d70c61eeb8f9828c467c8a4cf31c1d9c573
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

cmake/QtIRGitHelpers.cmake

@@ -181,6 +181,7 @@ function(qt_ir_clone_one_submodule submodule_name)
     set(oneValueArgs
         ALTERNATES
         BASE_URL
+        DEPTH
         WORKING_DIRECTORY
     )
     set(multiValueArgs "")
@@ -263,6 +264,9 @@ function(qt_ir_clone_one_submodule submodule_name)
         else()
             list(APPEND clone_args --no-checkout)
         endif()
+        if(arg_DEPTH)
+            list(APPEND clone_args --depth "${arg_DEPTH}")
+        endif()
         list(APPEND clone_args ${progress_args})
         qt_ir_execute_process_and_log_and_handle_error(
             COMMAND_ARGS git clone ${clone_args} "${mirror_or_original_url}" "${submodule_path}"
@@ -1063,6 +1067,7 @@ function(qt_ir_handle_init_submodules prefix)
     set(oneValueArgs
         ALTERNATES
         BASE_URL
+        DEPTH
         PARENT_REPO_BASE_GIT_PATH
         WORKING_DIRECTORY
     )
@@ -1123,6 +1128,7 @@ function(qt_ir_handle_init_submodules prefix)
         qt_ir_clone_one_submodule(${submodule_name}
             ALTERNATES ${arg_ALTERNATES}
             BASE_URL ${arg_BASE_URL}
+            DEPTH "${arg_DEPTH}"
             WORKING_DIRECTORY "${working_directory}"
             ${branch_flag}
             ${fetch_flag}
@@ -1163,6 +1169,7 @@ function(qt_ir_handle_init_submodules prefix)
                     SUBMODULES "all"
 
                     BASE_URL "${base_url}"
+                    DEPTH "${arg_DEPTH}"
                     PARENT_REPO_BASE_GIT_PATH "${submodule_base_git_path}"
                     WORKING_DIRECTORY "${working_directory}/${submodule_name}"
 

cmake/QtIRHelp.txt

@@ -122,6 +122,16 @@ Options:
 
         Note that this negates the disk usage benefits gained from the use
         of `--alternates'.
+
+    --depth <n>
+        Creates a shallow clone with a history truncated to <n> commits for
+        each submodule that is cloned, by passing `--depth <n>' to `git
+        clone'. This also applies recursively to submodules of submodules
+        (e.g. qtwebengine's third-party dependencies).
+
+        This option only affects submodules that are freshly cloned; it has
+        no effect on already-cloned submodules that are merely updated or
+        fetched.
     --mirror <url-base>
         Uses <url-base> as the base URL for submodule git mirrors.
 

cmake/QtIRHelpers.cmake

@@ -312,6 +312,7 @@ function(qt_ir_run_after_args_parsed top_level_src_path out_var_exit_reason)
     # Get some additional options to pass down.
     qt_ir_get_option_as_existing_absolute_path(alternates alternates)
     qt_ir_get_option_as_cmake_flag_option(branch "CHECKOUT_BRANCH" checkout_branch_option)
+    qt_ir_get_option_value(depth depth)
 
     # The prefix for the cmake-style 'dictionary' that will be used by various functions.
     set(prefix "ir_top")
@@ -321,6 +322,7 @@ function(qt_ir_run_after_args_parsed top_level_src_path out_var_exit_reason)
         ALTERNATES "${alternates}"
         ALREADY_INITIALIZED_SUBMODULES "${already_initialized_submodules}"
         BASE_URL "${base_url}"
+        DEPTH "${depth}"
         PARENT_REPO_BASE_GIT_PATH "${qt5_repo_name}"
         PROCESS_SUBMODULES_FROM_COMMAND_LINE
         WORKING_DIRECTORY "${working_directory}"

cmake/QtIROptionsHelpers.cmake

@@ -16,6 +16,7 @@ macro(qt_ir_set_known_command_line_options)
     qt_ir_commandline_option(codereview-username TYPE string)
     qt_ir_commandline_option(codereview-https TYPE boolean)
     qt_ir_commandline_option(copy-objects TYPE boolean)
+    qt_ir_commandline_option(depth TYPE string)
     qt_ir_commandline_option(fetch TYPE boolean DEFAULT_VALUE yes)
     qt_ir_commandline_option(force SHORT_NAME f TYPE boolean)
     qt_ir_commandline_option(force-hooks TYPE boolean)