From 7b24ffa936880619f54c8cc1a459a0328238657c Mon Sep 17 00:00:00 2001
From: Alexandru Croitor <alexandru.croitor@qt.io>
Date: Mon, 18 Jul 2022 14:14:41 +0200
Subject: [PATCH] CMake: Improve Qt6HostInfo package lookup condition

Instead of checking if QT_HOST_PATH is set during user project
configuration to find out if Qt6HostInfo should be looked up,
record if QT_HOST_PATH was provided during Qt configuration
into Qt6Dependencies.cmake and look up the package in a user
project based on that information.

This improves handling of the case where cmake is directly used
to configure a Qt project (instead of qt-cmake), which means no
QT_HOST_PATH might be set by the user, and then cmake would error out
saying that e.g. Qt6CoreTools is not found, instead of saying that
Qt6HostInfo is not found.

Pick-to: 6.4
Task-number: QTBUG-104998
Change-Id: I0377d5440e4b5b295af73cfd4b5188f61d48e440
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
---
 cmake/QtBuild.cmake                   |  3 ++-
 cmake/QtConfigDependencies.cmake.in   |  3 ++-
 cmake/QtPostProcessHelpers.cmake      |  4 +++-
 cmake/QtPublicDependencyHelpers.cmake | 10 +++++++++-
 4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/cmake/QtBuild.cmake b/cmake/QtBuild.cmake
index d3d41dbd07d..4b7cc643bb2 100644
--- a/cmake/QtBuild.cmake
+++ b/cmake/QtBuild.cmake
@@ -558,7 +558,8 @@ if(CMAKE_CROSSCOMPILING)
     endif()
 endif()
 
-_qt_internal_find_host_info_package()
+_qt_internal_determine_if_host_info_package_needed(__qt_build_requires_host_info_package)
+_qt_internal_find_host_info_package("${__qt_build_requires_host_info_package}")
 
 # TODO: This block provides support for old variables. It should be removed once
 #       we remove all references to these variables in other Qt module repos.
diff --git a/cmake/QtConfigDependencies.cmake.in b/cmake/QtConfigDependencies.cmake.in
index aabfa90328e..a369b9035f7 100644
--- a/cmake/QtConfigDependencies.cmake.in
+++ b/cmake/QtConfigDependencies.cmake.in
@@ -1,6 +1,7 @@
 set(@INSTALL_CMAKE_NAMESPACE@_FOUND FALSE)
 
-_qt_internal_find_host_info_package()
+set(__qt_platform_requires_host_info_package "@platform_requires_host_info_package@")
+_qt_internal_find_host_info_package(${__qt_platform_requires_host_info_package})
 
 # note: _third_party_deps example: "ICU\\;FALSE\\;1.0\\;i18n uc data;ZLIB\\;FALSE\\;\\;"
 set(__qt_third_party_deps "@third_party_deps@")
diff --git a/cmake/QtPostProcessHelpers.cmake b/cmake/QtPostProcessHelpers.cmake
index d3f917af8d9..5507f552de3 100644
--- a/cmake/QtPostProcessHelpers.cmake
+++ b/cmake/QtPostProcessHelpers.cmake
@@ -369,7 +369,9 @@ function(qt_internal_create_qt6_dependencies_file)
 endif()")
     endif()
 
-    if(third_party_deps)
+    _qt_internal_determine_if_host_info_package_needed(platform_requires_host_info_package)
+
+    if(third_party_deps OR platform_requires_host_info_package)
         # Setup build and install paths.
         set(path_suffix "${INSTALL_CMAKE_NAMESPACE}")
 
diff --git a/cmake/QtPublicDependencyHelpers.cmake b/cmake/QtPublicDependencyHelpers.cmake
index 5abd9cff384..2e3db75007e 100644
--- a/cmake/QtPublicDependencyHelpers.cmake
+++ b/cmake/QtPublicDependencyHelpers.cmake
@@ -192,8 +192,16 @@ macro(_qt_internal_save_find_package_context_for_debugging infix)
     endif()
 endmacro()
 
-macro(_qt_internal_find_host_info_package)
+function(_qt_internal_determine_if_host_info_package_needed out_var)
+    set(needed FALSE)
     if(NOT "${QT_HOST_PATH}" STREQUAL "")
+        set(needed TRUE)
+    endif()
+    set(${out_var} "${needed}" PARENT_SCOPE)
+endfunction()
+
+macro(_qt_internal_find_host_info_package platform_requires_host_info)
+    if(${platform_requires_host_info})
         find_package(Qt6HostInfo
                      CONFIG
                      REQUIRED