Add test illustrating crash when PythonQt is initialized in dynamically loaded lib

Author: jcfr

CMakeLists.txt

@@ -302,5 +302,37 @@ if(BUILD_TESTING)
     NAME tests_PythonQtTestMain
     COMMAND ${Slicer_LAUNCH_COMMAND} $<TARGET_FILE:PythonQtCppTests> tests/PythonQtTestMain
     )
+
+  #
+  # tests_PythonQtDynamicLoading: This test checks that a dynamically loaded library (itself linked against
+  #                               PythonQt) properly initializes PythonQt.
+  #
+
+  add_library(PythonQtDynamicLoaderSharedLibrary SHARED tests/PythonQtDynamicLoaderSharedLibrary.cpp)
+  target_link_libraries(PythonQtDynamicLoaderSharedLibrary PythonQt)
+
+  add_executable(PythonQtDynamicLoader tests/PythonQtDynamicLoader.cpp)
+  target_link_libraries(PythonQtDynamicLoader ${QT_LIBRARIES})
+
+  # Since setting the ENVIRONMENT property value with semicolon (e.g. PATH) is not supported, we
+  # generate a wrapper script to update PATH and LD_LIBRARY_PATH.
+  set(test_wrapper "${CMAKE_CURRENT_BINARY_DIR}/test_wrapper.cmake")
+  file(WRITE ${test_wrapper} "
+if(UNIX)
+  set(ENV{LD_LIBRARY_PATH} \"\$ENV{LD_LIBRARY_PATH}:.\")
+else()
+  set(ENV{PATH} \"\$ENV{PATH};.\")
+endif()
+execute_process(COMMAND \${TARGET_FILE} RESULT_VARIABLE result)
+if(NOT result EQUAL 0)
+  message(FATAL_ERROR \"test failed ! [result: \${result}]\")
+endif()
+")
+
+  add_test(
+    NAME tests_PythonQtDynamicLoading
+    COMMAND ${CMAKE_COMMAND} -DTARGET_FILE=$<TARGET_FILE:PythonQtDynamicLoader> -P ${test_wrapper}
+    )
+
 endif()
 

tests/PythonQtDynamicLoader.cpp

@@ -0,0 +1,50 @@
+
+#include <QApplication>
+#include <QLibrary>
+#include <QtGlobal>
+
+#include <cstdlib>
+#include <iostream>
+
+int main(int argc, char* argv[])
+{
+  QApplication qapp(argc, argv);
+
+#ifdef Q_OS_WIN32
+  std::cout << "PATH [" << qPrintable(qgetenv("PATH")) << "]" << std::endl;
+#else
+  std::cout << "LD_LIBRARY_PATH [" << qPrintable(qgetenv("LD_LIBRARY_PATH")) << "]" << std::endl;
+#endif
+
+
+  QLibrary library("PythonQtDynamicLoaderSharedLibrary");
+  if (!library.load())
+    {
+    std::cerr << "Failed to load 'PythonQtDynamicLoaderSharedLibrary': "
+      << qPrintable(library.errorString()) << std::endl;
+    return EXIT_FAILURE;
+    }
+
+  //
+  // Resolve and invoke 'this_function_returns_42' function.
+  //
+  typedef int (*FUNC_RETURNS_INT_TYPE)();
+  FUNC_RETURNS_INT_TYPE func = (FUNC_RETURNS_INT_TYPE) library.resolve("this_function_returns_42");
+  if (!func)
+    {
+    std::cerr << "Failed to resolve symbol 'this_function_returns_42'" << std::endl;
+    return EXIT_FAILURE;
+    }
+  int result = func();
+  int expected = 42;
+  if (result != expected)
+    {
+    std::cerr << "Problem with function 'this_function_returns_42':\n"
+              << "\tresult: " << result << "\n"
+              << "\texpected: " << expected
+              << std::endl;
+    return EXIT_FAILURE;
+    }
+  return EXIT_SUCCESS;
+}
+

tests/PythonQtDynamicLoaderSharedLibrary.cpp

@@ -0,0 +1,32 @@
+
+
+#include "PythonQt.h"
+
+#ifdef Q_OS_WIN
+#define MY_EXPORT __declspec(dllexport)
+#else
+#define MY_EXPORT
+#endif
+
+extern "C"
+{
+
+  int MY_EXPORT this_function_returns_42()
+  {
+    return 42;
+  }
+
+}
+
+struct StaticInitializer
+{
+  StaticInitializer()
+  {
+    std::cout << "PythonQtDynamicLoaderSharedLibrary::StaticInitializer" << std::endl;
+    PythonQt::init(PythonQt::IgnoreSiteModule | PythonQt::RedirectStdOut);
+  }
+};
+
+
+StaticInitializer staticInitializer;
+