1 files changed, 60 insertions, 5 deletions
diff --git a/cmake/qt.toolchain.cmake.in b/cmake/qt.toolchain.cmake.in
index 79a37fd95a..d5fc183c74 100644
--- a/cmake/qt.toolchain.cmake.in
+++ b/cmake/qt.toolchain.cmake.in
@@ -2,7 +2,10 @@ set(__qt_toolchain_used_variables
     QT_CHAINLOAD_TOOLCHAIN_FILE
     QT_TOOLCHAIN_INCLUDE_FILE
     QT_TOOLCHAIN_RELOCATABLE_CMAKE_DIR
-    QT_TOOLCHAIN_RELOCATABLE_PREFIX)
+    QT_TOOLCHAIN_RELOCATABLE_PREFIX
+    QT_HOST_PATH
+    QT_HOST_PATH_CMAKE_DIR
+)
 @init_additional_used_variables@
 
 # Make cache variables used by this toolchain file available to the
@@ -19,8 +22,6 @@ if($ENV{_QT_TOOLCHAIN_VARS_INITIALIZED})
     endforeach()
 endif()
 
-@init_qt_host_path@
-@init_qt_host_path_cmake_dir@
 @init_original_toolchain_file@
 @init_vcpkg@
 
@@ -120,8 +121,6 @@ if(__qt_toolchain_additional_packages_prefixes)
 endif()
 unset(__qt_toolchain_additional_packages_prefixes)
 
-@init_qt_host_path_checks@
-
 # Allow customization of the toolchain file by placing an additional file next to it.
 set(__qt_toolchain_extra_file "${CMAKE_CURRENT_LIST_DIR}/qt.toolchain.extra.cmake")
 if(EXISTS "${__qt_toolchain_extra_file}")
@@ -141,6 +140,62 @@ if(QT_TOOLCHAIN_INCLUDE_FILE)
     endif()
 endif()
 
+# Set up QT_HOST_PATH and do sanity checks.
+# A host path is required when cross-compiling but optional when doing a native build.
+set(__qt_toolchain_host_path_required "@qt_host_path_required@")
+set(__qt_toolchain_initial_qt_host_path
+    "@qt_host_path_absolute@")
+set(__qt_toolchain_initial_qt_host_path_cmake_dir
+    "@qt_host_path_cmake_dir_absolute@")
+
+# Prefer initially configured path if none was explicitly set.
+if(NOT DEFINED QT_HOST_PATH AND __qt_toolchain_initial_qt_host_path
+      AND EXISTS "${__qt_toolchain_initial_qt_host_path}")
+    set(QT_HOST_PATH "${__qt_toolchain_initial_qt_host_path}" CACHE PATH "")
+endif()
+
+if(NOT QT_HOST_PATH STREQUAL "")
+    get_filename_component(__qt_toolchain_host_path_absolute "${QT_HOST_PATH}" ABSOLUTE)
+endif()
+
+if(__qt_toolchain_host_path_required AND
+      ("${QT_HOST_PATH}" STREQUAL "" OR NOT EXISTS "${__qt_toolchain_host_path_absolute}"))
+    message(FATAL_ERROR
+        "To use a cross-compiled Qt, please set the QT_HOST_PATH cache variable to the location "
+        "of your host Qt installation.")
+endif()
+
+# QT_HOST_PATH_CMAKE_DIR is needed to work around the rerooting issue when looking for host tools
+# See REROOT_PATH_ISSUE_MARKER.
+# Prefer initially configured path if none was explicitly set.
+if(__qt_toolchain_host_path_required AND NOT DEFINED QT_HOST_PATH_CMAKE_DIR)
+    if(__qt_toolchain_initial_qt_host_path_cmake_dir
+          AND EXISTS "${__qt_toolchain_initial_qt_host_path_cmake_dir}")
+        set(QT_HOST_PATH_CMAKE_DIR "${__qt_toolchain_initial_qt_host_path_cmake_dir}" CACHE PATH "")
+    else()
+        # First try to auto-compute the location instead of requiring to set QT_HOST_PATH_CMAKE_DIR
+        # explicitly.
+        set(__qt_candidate_host_path_cmake_dir "${QT_HOST_PATH}/lib/cmake")
+        if(__qt_candidate_host_path_cmake_dir AND EXISTS "${__qt_candidate_host_path_cmake_dir}")
+            set(QT_HOST_PATH_CMAKE_DIR
+                "${__qt_candidate_host_path_cmake_dir}" CACHE PATH "")
+        endif()
+    endif()
+endif()
+
+if(NOT QT_HOST_PATH_CMAKE_DIR STREQUAL "")
+    get_filename_component(__qt_toolchain_host_path_cmake_dir_absolute
+                           "${QT_HOST_PATH_CMAKE_DIR}" ABSOLUTE)
+endif()
+
+if(__qt_toolchain_host_path_required AND
+      ("${QT_HOST_PATH_CMAKE_DIR}" STREQUAL ""
+       OR NOT EXISTS "${__qt_toolchain_host_path_cmake_dir_absolute}"))
+    message(FATAL_ERROR
+        "To use a cross-compiled Qt, please set the QT_HOST_PATH_CMAKE_DIR cache variable to "
+        "the location of your host Qt installation lib/cmake directory.")
+endif()
+
 # Compile tests only see a restricted set of variables.
 # All cache variables, this toolchain file uses, must be made available to compile tests,
 # because this toolchain file will be included there too.