Ugly fix for handling QT_SOURCE_TREE

QT_SOURCE_TREE is a variable that is set in qtbase/.qmake.conf.
In qtbase, it's used throughout various
projects to find cpp sources when building standalone tests (among
other things).
Everything works fine with qmake, because even if qmake is invoked
on the tests subfolder, qmake searches up the source directory tree
until it finds a .qmake.conf file, and uses that.

When building qttools with qmake, the qdoc project expects
to have a QT_SOURCE_TREE value, but it's not actually set in the
qttools/.qmake.conf file, so the generated include paths that use
that value are incorrect. Curiously the build still succeeds.

Now in CMake land we replaced QT_SOURCE_TREE with
CMAKE_SOURCE_DIR, but that does not work properly when doing a
standalone tests build, because the project in that case is the
tests one, and not the qtbase one, so configuration fails in a
developer build when trying to configure some private tests.

So far I've found that only qtbase actively uses this value.
A temporary fix is to save the qtbase source directory into a
QT_SOURCE_TREE variable inside the generated
BuildInternalsExtra.cmake file.

The pro2cmake script is changed to handle presence of QT_SOURCE_TREE
in a qrc file path. This is handled by finding the location of a
.qmake.conf file starting from the project file absolute path.
This is needed to stop the script from crashing when handling
the mimedatabase test projects for example.

The change also regenerates the relevant failing test projects, and
thus standalone tests (when doing developer builds aka private_tests
enabled) now configure and build successfully.

Change-Id: I15adc6f4ab6e3056c43ed850196204e2229c4d98
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

3 files changed, 13 insertions, 0 deletions

diff --git a/cmake/QtBuildInternalsExtra.cmake.in b/cmake/QtBuildInternalsExtra.cmake.in
index 6f070ed043..8ec5c95d56 100644
--- a/cmake/QtBuildInternalsExtra.cmake.in
+++ b/cmake/QtBuildInternalsExtra.cmake.in
@@ -19,3 +19,6 @@ endif()
 # Propagate non-prefix builds.
 set(QT_WILL_INSTALL @QT_WILL_INSTALL@ CACHE BOOL
     "Boolean indicating if doing a Qt prefix build (vs non-prefix build)." FORCE)
+
+set(QT_SOURCE_TREE "@QT_SOURCE_TREE@" CACHE PATH
+"A path to the source tree of the previously configured QtBase project." FORCE)
diff --git a/cmake/QtPostProcess.cmake b/cmake/QtPostProcess.cmake
index f56eb801ea..c10f827575 100644
--- a/cmake/QtPostProcess.cmake
+++ b/cmake/QtPostProcess.cmake
@@ -265,6 +265,8 @@ endfunction()
 
 function(qt_generate_build_internals_extra_cmake_code)
     if(PROJECT_NAME STREQUAL "QtBase")
+
+        set(QT_SOURCE_TREE "${QtBase_SOURCE_DIR}")
         qt_path_join(extra_file_path
                      ${QT_CONFIG_BUILD_DIR}
                      ${INSTALL_CMAKE_NAMESPACE}BuildInternals/QtBuildInternalsExtra.cmake)
diff --git a/cmake/QtSetup.cmake b/cmake/QtSetup.cmake
index 9fac9875c5..2958ba08cc 100644
--- a/cmake/QtSetup.cmake
+++ b/cmake/QtSetup.cmake
@@ -63,6 +63,14 @@ if (PROJECT_NAME STREQUAL "QtBase")
     unset(__qt_will_install_value)
 endif()
 
+# Specify the QT_SOURCE_TREE only when building qtbase. Needed by some tests when the tests are
+# built as part of the project, and not standalone. For standalone tests, the value is set in
+# QtBuildInternalsExtra.cmake.
+if(PROJECT_NAME STREQUAL "QtBase")
+    set(QT_SOURCE_TREE "${QtBase_SOURCE_DIR}" CACHE PATH
+        "A path to the source tree of the previously configured QtBase project." FORCE)
+endif()
+
 if(FEATURE_developer_build)
     if(DEFINED QT_CMAKE_EXPORT_COMPILE_COMMANDS)
         set(CMAKE_EXPORT_COMPILE_COMMANDS ${QT_CMAKE_EXPORT_COMPILE_COMMANDS})