From ca4f26320dba0452b8b3a2910bb39ba12c109e25 Mon Sep 17 00:00:00 2001 From: Joerg Bornemann Date: Fri, 8 Jan 2021 14:31:26 +0100 Subject: [PATCH] Lower the CMake minimum required version for single-config builds Ubuntu 20.04 is a supported platform and comes with CMake 3.16. The current state of the Qt build works fine with this CMake version, mainly because the default build on Linux is single-config. For multi-config builds we have higher version requirements as documented in cmake/README.md. This lowers the barrier for users using single-config builds who don't want or cannot upgrade to CMake >= 3.18. For Ninja Multi-Config builds, which were introduced by CMake 3.17, we yield a warning that 3.18.3 is the lowest supported version. Change-Id: Ia918b9f2b494508e86301ffc0e138d3ad4dbaf86 Reviewed-by: Craig Scott Reviewed-by: Lars Knoll (cherry picked from commit 20a17911576297f22b9da9849b677476c2d6e0ea) Reviewed-by: Qt Cherry-pick Bot --- .cmake.conf | 2 +- cmake/QtCMakeVersionHelpers.cmake | 10 ++++++++++ 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/.cmake.conf b/.cmake.conf index bc81f6a9529..1ada086881a 100644 --- a/.cmake.conf +++ b/.cmake.conf @@ -1,7 +1,7 @@ set(QT_REPO_MODULE_VERSION "6.0.1") # Minimum requirement for building Qt -set(QT_MIN_SUPPORTED_CMAKE_VERSION "3.18") +set(QT_MIN_SUPPORTED_CMAKE_VERSION "3.16") # Policy settings for commands defined by qtbase. These will also be injected # into the top level policy scope of each Qt module when building Qt so that diff --git a/cmake/QtCMakeVersionHelpers.cmake b/cmake/QtCMakeVersionHelpers.cmake index aca1c50206e..955d9044cb2 100644 --- a/cmake/QtCMakeVersionHelpers.cmake +++ b/cmake/QtCMakeVersionHelpers.cmake @@ -124,6 +124,16 @@ function(qt_internal_warn_about_unsuitable_cmake_versions) "CMake version used: '${unsuitable_version}'") endif() endforeach() + + # Ninja Multi-Config was introduced in 3.17, but we recommend 3.18. + set(min_nmc_cmake_version "3.18.3") + if(CMAKE_GENERATOR STREQUAL "Ninja Multi-Config" + AND CMAKE_VERSION VERSION_LESS ${min_nmc_cmake_version}) + message(WARNING + "You are using CMake ${CMAKE_VERSION} with the Ninja Multi-Config generator. " + "This combination is unsupported. " + "Please upgrade to at least CMake ${min_nmc_cmake_version}. ") + endif() endfunction() # Functions don't have their own policy scope, so the policy settings modified