shiboken: Improve the libdir for windows

With virtualenv 20 we have the case where the first
path in the PYTHON_LIBRARIES cmake variable was wrong:
    a_virtual_env/libs/python3.lib
so the python code inside the helper didn't have a proper
check if the file was valid or it was just a wrong construct.

Additionally, the 'prefix' variable will contain the virtual
environment directory location, which will not contain the 'libs'
directory, because that's included in the system's installation path.
To solve this, we use the 'INCLUDEPY' directory, which is correct
as a base to create the real 'libs' one.

Task-number: PYSIDE-1231
Change-Id: Ifca08d74c49cd57572836a087edb96c089266dc7
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

3 files changed, 17 insertions, 3 deletions

diff --git a/build_scripts/main.py b/build_scripts/main.py
index 674048e23..cf56850df 100644
--- a/build_scripts/main.py
+++ b/build_scripts/main.py
@@ -530,7 +530,13 @@ class PysideBuild(_build):
         self.py_scripts_dir = py_scripts_dir
         if py_libdir is None or not os.path.exists(py_libdir):
             if sys.platform == "win32":
-                py_libdir = os.path.join(py_prefix, "libs")
+                # For virtual environments on Windows, the py_prefix will contain a path pointing
+                # to it, instead of the system Python installation path.
+                # Since INCLUDEPY contains a path to the system location, we use the same base
+                # directory to define the py_libdir variable.
+                py_libdir = os.path.join(os.path.dirname(py_include_dir), "libs")
+                if not os.path.isdir(py_libdir):
+                    raise DistutilsSetupError("Failed to locate the 'libs' directory")
             else:
                 py_libdir = os.path.join(py_prefix, "lib")
         if py_include_dir is None or not os.path.exists(py_include_dir):
diff --git a/sources/pyside2/tests/pysidetest/CMakeLists.txt b/sources/pyside2/tests/pysidetest/CMakeLists.txt
index 4dcf9b89c..3ba2ad29d 100644
--- a/sources/pyside2/tests/pysidetest/CMakeLists.txt
+++ b/sources/pyside2/tests/pysidetest/CMakeLists.txt
@@ -107,10 +107,17 @@ set_property(TARGET testbinding PROPERTY OUTPUT_NAME "testbinding${SHIBOKEN_PYTH
 if(WIN32)
     set_property(TARGET testbinding PROPERTY SUFFIX ".pyd")
 endif()
+
+if(PYTHON_LIMITED_API)
+    set(TESTBINDING_PYTHON_LIBS ${PYTHON_LIMITED_LIBRARIES})
+else()
+    set(TESTBINDING_PYTHON_LIBS ${PYTHON_LIBRARIES})
+endif()
+
 target_link_libraries(testbinding
                       pysidetest
                       pyside2
-                      ${PYTHON_LIBRARIES}
+                      ${TESTBINDING_PYTHON_LIBS}
                       Shiboken2::libshiboken
                       ${Qt5Core_LIBRARIES}
                       ${Qt5Gui_LIBRARIES}
diff --git a/sources/shiboken2/data/shiboken_helpers.cmake b/sources/shiboken2/data/shiboken_helpers.cmake
index 9772ee597..ee6c6c4d5 100644
--- a/sources/shiboken2/data/shiboken_helpers.cmake
+++ b/sources/shiboken2/data/shiboken_helpers.cmake
@@ -287,8 +287,9 @@ macro(shiboken_check_if_limited_api)
     # On other platforms, this result is not used at all.
     execute_process(
         COMMAND ${PYTHON_EXECUTABLE} -c "if True:
+            import os
             for lib in '${PYTHON_LIBRARIES}'.split(';'):
-                if '/' in lib:
+                if '/' in lib and os.path.isfile(lib):
                     prefix, py = lib.rsplit('/', 1)
                     if py.startswith('python3'):
                         print(prefix + '/python3.lib')