CMake: Integrate init-repository with the configure script

Calling configure will now implicitly run init-repository when
appropriate. See further down below for what "appropriate" means.

All supported init-repository options can be passed to configure as
except for -mirror, -oslo, -berlin.

This includes useful options like -submodules, -no-resolve-deps and
-no-optional-deps.

When running configure on a qt5.git clone without any submodules
cloned, configure will exit with a helpful error message suggesting to
pass -init-submodules, so it automatically clones missing repositories.
This means cloning is opt-in, so that internet access is not done
implicitly.

The error message also suggests passing the -submodules option.
This will affect which submodules will be cloned by init-repository
and which submodules will be configured by configure.
In this case -submodules is effectively an alias of
init-repository's -module-subset for cloning purposes.

When calling configure a second time, without -init-submodules, on an
already configured repo, init-repository behavior is entirely skipped.

-submodules now accepts init-repository-style special values like
"essential", "addon", "all", "existing", "-deprecated" for the purpose
of cloning submodules. The values are then translated into actual repos
that should also be configured or skipped by configure.

The default subset of cloned submodules is currently the same one as
init-repository, "default", which clones 44 actively maintained
repositories as well as deprecated submodules.

If configure is called a second time WITH -init-submodules, it's the
same as calling init-repository --force to re-initialize submodules.
In this case passing something like
 --submodules existing,<additional-submodules>
might make sense to add or remove submodules.

As a drive-by this also fixes the bug where you couldn't pass a
  configure -- -DFOO=0
parameter to configure, because it got treated as '0>', redirecting
from a different stream than stdout, leading to empty content in the
file.

[ChangeLog][General][Build System] The configure script now implicitly
calls init-repository when appropriate and accepts init-repository
command line options.

Fixes: QTBUG-120030
Task-number: QTBUG-122622
Change-Id: Iedbfcbf0a87c8ee89e40d00b6377b68296a65a62
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

cmake/QtIRCommandLineHelpers.cmake

@@ -247,12 +247,29 @@ function(qt_ir_get_raw_args_from_optfile optfile_path out_var)
     set(${out_var} "${args}" PARENT_SCOPE)
 endfunction()
 
- # Reads the optfile_path, iterates over the given command line arguments,
- # sets the input for recongized options.
- #
- # IGNORE_UNKNOWN_ARGS tells the function not to fail if it encounters an unknown
- # option, needed when the script is called from the configure script with
- # configure-only-known options.
+# Reads the optfile_path, iterates over the given command line arguments,
+# sets the input for recongized options.
+#
+# Handles the following styles of CLI arguments:
+#  --no-foo / --disable-foo
+#  -no-foo / -disable-foo
+#  --foo=<values>
+#  --foo <values>
+#  -foo <values>
+#  --foo
+#  -foo
+#  --f
+#  -f
+#
+# Currently handles the following types of CLI arguments:
+#  string
+#  boolean
+#  void
+#
+# IGNORE_UNKNOWN_ARGS tells the function not to fail if it encounters an unknown
+# option, and instead append it to a global list of unknown options.
+# It is needed when the script is called from the configure script with
+# configure-only-known options.
 function(qt_ir_process_args_from_optfile optfile_path)
     set(options IGNORE_UNKNOWN_ARGS)
     set(oneValueArgs "")
@@ -286,7 +303,13 @@ function(qt_ir_process_args_from_optfile optfile_path)
             set(opt "${CMAKE_MATCH_1}")
             unset(val)
         else()
-            qt_ir_add_error("Invalid command line parameter '${arg}'.")
+            if(NOT arg_IGNORE_UNKNOWN_ARGS)
+                qt_ir_add_error("Invalid command line parameter '${arg}'.")
+            else()
+                message(DEBUG "Unknown command line parameter '${arg}'. Collecting.")
+                qt_ir_append_unknown_args("${arg}")
+                continue()
+            endif()
         endif()
 
         set(type "${commandline_option_${opt}_type}")
@@ -295,7 +318,8 @@ function(qt_ir_process_args_from_optfile optfile_path)
             if(NOT arg_IGNORE_UNKNOWN_ARGS)
                 qt_ir_add_error("Unknown command line option '${arg}'.")
             else()
-                message(DEBUG "Unknown command line option '${arg}'. Ignoring.")
+                message(DEBUG "Unknown command line option '${arg}'. Collecting.")
+                qt_ir_append_unknown_args("${arg}")
                 continue()
             endif()
         endif()
@@ -332,6 +356,17 @@ function(qt_ir_set_unhandled_args args)
     set_property(GLOBAL PROPERTY _qt_ir_unhandled_args "${args}")
 endfunction()
 
+# Adds to the unknown command line args.
+function(qt_ir_append_unknown_args args)
+    set_property(GLOBAL APPEND PROPERTY _qt_ir_unknown_args ${args})
+endfunction()
+
+# Gets the unhandled command line args.
+function(qt_ir_get_unknown_args out_var)
+    get_property(args GLOBAL PROPERTY _qt_ir_unknown_args)
+    set(${out_var} "${args}" PARENT_SCOPE)
+endfunction()
+
 # Gets the unsupported options that init-repository.pl supports, but the cmake port does
 # not support.
 function(qt_ir_get_unsupported_options out_var)