From ba2ab5fa432a19fdb8d051e5fa4057d7156401f4 Mon Sep 17 00:00:00 2001
From: Orkun Tokdemir <orkun.tokdemir@qt.io>
Date: Mon, 23 Oct 2023 18:52:56 +0200
Subject: [PATCH] CMake: Set AUTOGEN_BETTER_GRAPH_MULTI_CONFIG

Since https://gitlab.kitware.com/cmake/cmake/-/merge_requests/8919 is merged, `qtbase` should be updated accordingly. If `CMake` is equal or greater than `3.29`. `timestamp_$<CONFIG>` is used instead of `timestamp`.

This commit reimplements 8041bfba47305352627d910930e52da496904c17 which is reverted with 4b1d96ea1b16e3eef2222de78677a4d99a87940f

Change-Id: I335e3855c1a11c404202ae7b74f0c356b8fe53bd
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
---
 src/corelib/Qt6CoreMacros.cmake               | 15 +++++++++---
 .../src/cmake/cmake-standard-properties.qdoc  | 24 +++++++++++++++++++
 2 files changed, 36 insertions(+), 3 deletions(-)
 create mode 100644 src/corelib/doc/src/cmake/cmake-standard-properties.qdoc

diff --git a/src/corelib/Qt6CoreMacros.cmake b/src/corelib/Qt6CoreMacros.cmake
index ebd94dd82ae..4b96776760d 100644
--- a/src/corelib/Qt6CoreMacros.cmake
+++ b/src/corelib/Qt6CoreMacros.cmake
@@ -1238,9 +1238,18 @@ function(qt6_extract_metatypes target)
             add_dependencies(${target}_automoc_json_extraction ${target}_autogen)
             _qt_internal_assign_to_internal_targets_folder(${target}_automoc_json_extraction)
         else()
-            set(cmake_autogen_timestamp_file
-                "${target_autogen_build_dir}/timestamp"
-            )
+            set(timestamp_file "${target_autogen_build_dir}/timestamp")
+            set(timestamp_file_with_config "${timestamp_file}_$<CONFIG>")
+            if (is_multi_config AND CMAKE_VERSION VERSION_GREATER_EQUAL "3.29"
+                AND NOT QT_INTERNAL_USE_OLD_AUTOGEN_GRAPH_MULTI_CONFIG_METATYPES)
+                string(JOIN "" timestamp_genex
+                    "$<IF:$<BOOL:$<TARGET_PROPERTY:${target},"
+                    "AUTOGEN_BETTER_GRAPH_MULTI_CONFIG>>,"
+                    "${timestamp_file_with_config},${timestamp_file}>")
+                set(cmake_autogen_timestamp_file "${timestamp_genex}")
+            else()
+                set(cmake_autogen_timestamp_file ${timestamp_file})
+            endif()
 
             add_custom_command(OUTPUT ${type_list_file}
                 DEPENDS ${QT_CMAKE_EXPORT_NAMESPACE}::cmake_automoc_parser
diff --git a/src/corelib/doc/src/cmake/cmake-standard-properties.qdoc b/src/corelib/doc/src/cmake/cmake-standard-properties.qdoc
new file mode 100644
index 00000000000..a8ece6ba8f3
--- /dev/null
+++ b/src/corelib/doc/src/cmake/cmake-standard-properties.qdoc
@@ -0,0 +1,24 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
+
+/*!
+\page cmake-standard-property-autogen-better-graph-multi-config.html
+\ingroup cmake-standard-properties
+
+\title AUTOGEN_BETTER_GRAPH_MULTI_CONFIG
+
+\brief Improves the dependency graph for multi-configuration generators when you
+set it on a target.
+
+When this boolean property is enabled, \c{CMake} will generate more per-config targets.
+Thus, the dependency graph will be more accurate for multi-configuration
+generators and some recompilations will be avoided.
+
+Since Qt 6.8, this property is enabled by default. For older versions,
+you need to enable it manually to use it.
+However, \l{qt_extract_metatypes} and \l{qt_add_qml_module} were updated to
+support \c{AUTOGEN_BETTER_GRAPH_MULTI_CONFIG} in Qt 6.8, so you will get build
+errors, unless you patch the older Qt version to support it.
+
+See \l{https://cmake.org/cmake/help/latest/prop_tgt/AUTOGEN_BETTER_GRAPH_MULTI_CONFIG.html}{AUTOGEN_BETTER_GRAPH_MULTI_CONFIG} for more information.
+*/