Can build Qt5 applications.

backends.py

@@ -183,6 +183,9 @@ class Backend():
             commands += compiler.get_pic_flags()
         for dep in target.get_external_deps():
             commands += dep.get_compile_flags()
+            if isinstance(target, interpreter.Executable):
+                commands += dep.get_exe_flags()
+
         return commands
 
     def build_target_link_arguments(self, deps):

dependencies.py

@@ -62,6 +62,9 @@ class Dependency():
     def get_generate_rules(self):
         return []
 
+    def get_exe_flags(self):
+        return []
+
 class PkgConfigDependency(Dependency):
     pkgconfig_found = False
 
@@ -356,6 +359,11 @@ class Qt5Dependency(Dependency):
                               'Compiling @INFILE@ with the ui compiler')
         return [moc_rule, ui_rule]
 
+    def get_exe_flags(self):
+        # Qt5 seems to require this always.
+        # Fix this to be more portable, especially to MSVC.
+        return ['-fPIE']
+
 
 def get_dep_identifier(name, kwargs):
     elements = [name]

interpreter.py

@@ -85,6 +85,9 @@ class ExternalLibraryHolder(InterpreterObject):
     def get_link_flags(self):
         return self.el.get_link_flags()
     
+    def get_exe_flags(self):
+        return self.el.get_exe_flags()
+
 class Generator(InterpreterObject):
 
     def __init__(self, args, kwargs):

test cases/frameworks/4 qt5/main.cpp

@@ -4,8 +4,11 @@
 int main(int argc, char **argv) {
   QApplication app(argc, argv);
   MainWindow *win = new MainWindow();
-  win->setWindowTitle("Button demo app");
+  win->setWindowTitle("Meson Qt5 build test");
-  win->show();
 
-  return app.exec();
+  // Don't actually start the GUI so this
+  // can be run as a unit test.
+  //win->show();
+  //return app.exec();
+  return 0;
 }