Use separate Qt5Config.cmake inside build directory

Qt5Config restricts search paths of Qt components to ${_qt5_install_prefix}
to prevent accidentally using system Qt modules in case of restricted Qt
configuration. However this does not work properly when Qt is used without
installation, in particular when building cmake-based QtWebKit as a Qt
submodule, because ${_qt5_install_prefix} resolves to QtBase and does not
contain components from other modules.

This patch changes search path from ${_qt5_install_prefix} to all qt5
subdirectories.

Change-Id: Icf01a256097710889573ad69d847b9c3bffa1449
Reviewed-by: Kevin Funk <kevin.funk@kdab.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>

4 files changed, 47 insertions, 5 deletions

diff --git a/src/corelib/Qt5Config.cmake.in b/src/corelib/Qt5Config.cmake.in
index a872d0e917..75b53485b7 100644
--- a/src/corelib/Qt5Config.cmake.in
+++ b/src/corelib/Qt5Config.cmake.in
@@ -22,18 +22,24 @@ get_filename_component(_qt5_install_prefix \"${CMAKE_CURRENT_LIST_DIR}/..\" ABSO
 
 set(_Qt5_NOTFOUND_MESSAGE)
 
+include(${CMAKE_CURRENT_LIST_DIR}/Qt5ModuleLocation.cmake)
+
 foreach(module ${Qt5_FIND_COMPONENTS})
     find_package(Qt5${module}
         ${_Qt5_FIND_PARTS_QUIET}
         ${_Qt5_FIND_PARTS_REQUIRED}
-        PATHS \"${_qt5_install_prefix}\" NO_DEFAULT_PATH
+        PATHS ${_qt5_module_paths} NO_DEFAULT_PATH
     )
     if (NOT Qt5${module}_FOUND)
+        string(CONFIGURE ${_qt5_module_location_template} _expected_module_location @ONLY)
+
         if (Qt5_FIND_REQUIRED_${module})
-            set(_Qt5_NOTFOUND_MESSAGE \"${_Qt5_NOTFOUND_MESSAGE}Failed to find Qt5 component \\\"${module}\\\" config file at \\\"${_qt5_install_prefix}/Qt5${module}/Qt5${module}Config.cmake\\\"\\n\")
+            set(_Qt5_NOTFOUND_MESSAGE \"${_Qt5_NOTFOUND_MESSAGE}Failed to find Qt5 component \\\"${module}\\\" config file at \\\"${_expected_module_location}\\\"\\n\")
         elseif(NOT Qt5_FIND_QUIETLY)
-            message(WARNING \"Failed to find Qt5 component \\\"${module}\\\" config file at \\\"${_qt5_install_prefix}/Qt5${module}/Qt5${module}Config.cmake\\\"\")
+            message(WARNING \"Failed to find Qt5 component \\\"${module}\\\" config file at \\\"${_expected_module_location}\\\"\")
         endif()
+
+        unset(_expected_module_location)
     endif()
 endforeach()
 
diff --git a/src/corelib/Qt5ModuleLocation.cmake.in b/src/corelib/Qt5ModuleLocation.cmake.in
new file mode 100644
index 0000000000..5065ada56e
--- /dev/null
+++ b/src/corelib/Qt5ModuleLocation.cmake.in
@@ -0,0 +1,15 @@
+!!IF !isEmpty(_QMAKE_SUPER_CACHE_)
+get_filename_component(_qt5_root_dir \"${CMAKE_CURRENT_LIST_DIR}/../../../..\" ABSOLUTE)
+
+file(GLOB qtmodules ${_qt5_root_dir} "${_qt5_root_dir}/*")
+foreach(qtmodule ${qtmodules})
+    if(IS_DIRECTORY ${qtmodule})
+        list(APPEND _qt5_module_paths ${qtmodule})
+    endif()
+endforeach()
+!!ELSE
+set(_qt5_root_dir ${_qt5_install_prefix})
+set(_qt5_module_paths ${_qt5_install_prefix})
+!!ENDIF
+
+set(_qt5_module_location_template ${_qt5_root_dir})
diff --git a/src/corelib/Qt5ModuleLocationForInstall.cmake.in b/src/corelib/Qt5ModuleLocationForInstall.cmake.in
new file mode 100644
index 0000000000..e401b1fe34
--- /dev/null
+++ b/src/corelib/Qt5ModuleLocationForInstall.cmake.in
@@ -0,0 +1,4 @@
+set(_qt5_root_dir ${_qt5_install_prefix})
+set(_qt5_module_paths ${_qt5_install_prefix})
+
+set(_qt5_module_location_template ${_qt5_install_prefix}/Qt5@module@/Qt5@module@Config.cmake)
diff --git a/src/corelib/corelib.pro b/src/corelib/corelib.pro
index 616a9641a1..0bd7c9b99d 100644
--- a/src/corelib/corelib.pro
+++ b/src/corelib/corelib.pro
@@ -93,6 +93,12 @@ ctest_macros_file.CONFIG = verbatim
 cmake_umbrella_config_file.input = $$PWD/Qt5Config.cmake.in
 cmake_umbrella_config_file.output = $$DESTDIR/cmake/Qt5/Qt5Config.cmake
 
+cmake_umbrella_config_module_location.input = $$PWD/Qt5ModuleLocation.cmake.in
+cmake_umbrella_config_module_location.output = $$DESTDIR/cmake/Qt5/Qt5ModuleLocation.cmake
+
+cmake_umbrella_config_module_location_for_install.input = $$PWD/Qt5ModuleLocationForInstall.cmake.in
+cmake_umbrella_config_module_location_for_install.output = $$DESTDIR/cmake/install/Qt5/Qt5ModuleLocation.cmake
+
 cmake_umbrella_config_version_file.input = $$PWD/../../mkspecs/features/data/cmake/Qt5ConfigVersion.cmake.in
 cmake_umbrella_config_version_file.output = $$DESTDIR/cmake/Qt5/Qt5ConfigVersion.cmake
 
@@ -119,10 +125,21 @@ contains(CMAKE_INSTALL_DATA_DIR, "^\\.\\./.*"):!isEmpty(CMAKE_INSTALL_DATA_DIR)
 cmake_extras_mkspec_dir_for_install.input = $$PWD/Qt5CoreConfigExtrasMkspecDirForInstall.cmake.in
 cmake_extras_mkspec_dir_for_install.output = $$DESTDIR/cmake/install/Qt5Core/Qt5CoreConfigExtrasMkspecDir.cmake
 
-cmake_qt5_umbrella_module_files.files = $$cmake_umbrella_config_file.output $$cmake_umbrella_config_version_file.output
+cmake_qt5_umbrella_module_files.files = \
+    $$cmake_umbrella_config_file.output \
+    $$cmake_umbrella_config_version_file.output \
+    $$cmake_umbrella_config_module_location_for_install.output
+
 cmake_qt5_umbrella_module_files.path = $$[QT_INSTALL_LIBS]/cmake/Qt5
 
-QMAKE_SUBSTITUTES += ctest_macros_file cmake_umbrella_config_file cmake_umbrella_config_version_file cmake_extras_mkspec_dir cmake_extras_mkspec_dir_for_install
+QMAKE_SUBSTITUTES += \
+    ctest_macros_file \
+    cmake_umbrella_config_file \
+    cmake_umbrella_config_module_location \
+    cmake_umbrella_config_module_location_for_install \
+    cmake_umbrella_config_version_file \
+    cmake_extras_mkspec_dir \
+    cmake_extras_mkspec_dir_for_install
 
 ctest_qt5_module_files.files += $$ctest_macros_file.output $$cmake_extras_mkspec_dir_for_install.output