Qt5 apps compile with only a slight amount of cheating.

backends.py

@@ -142,7 +142,7 @@ class Backend():
                 else:
                     header_deps.append(src)
         for src in gen_src_deps:
-                obj_list.append(self.generate_single_compile(target, outfile, src, True, []))
+                obj_list.append(self.generate_single_compile(target, outfile, src, True))
         for src in target.get_sources():
             if not self.environment.is_header(src):
                 obj_list.append(self.generate_single_compile(target, outfile, src, False, header_deps))
@@ -540,14 +540,17 @@ class NinjaBackend(Backend):
         commands = self.generate_basic_compiler_flags(target, compiler)
         commands.append(compiler.get_include_arg(self.get_target_private_dir(target)))
         if is_generated:
-            rel_src = os.path.join(self.get_target_private_dir(target), src)
+            if '/' in src:
+                rel_src = src
+            else:
+                rel_src = os.path.join(self.get_target_private_dir(target), src)
         else:
             rel_src = os.path.join(self.build_to_src, target.get_source_subdir(), src)
         if os.path.isabs(src):
             src_filename = os.path.basename(src)
         else:
             src_filename = src
-        rel_obj = os.path.join(self.get_target_private_dir(target), src_filename)
+        rel_obj = os.path.join(self.get_target_private_dir(target), os.path.basename(src_filename))
         rel_obj += '.' + self.environment.get_object_suffix()
         dep_file = rel_obj + '.' + compiler.get_depfile_suffix()
         pchlist = target.get_pch()
@@ -573,8 +576,10 @@ class NinjaBackend(Backend):
         compiler_name = '%s_COMPILER' % compiler.get_language()
 
         element = NinjaBuildElement(rel_obj, compiler_name, rel_src)
-        if len(header_deps) > 0:
-            element.add_dep([os.path.join(self.get_target_private_dir(target), d) for d in header_deps])
+        for d in header_deps:
+            if not '/' in d:
+                d = os.path.join(self.get_target_private_dir(target), d)
+            element.add_dep(d)
         element.add_orderdep(pch_dep)
         element.add_item('DEPFILE', dep_file)
         element.add_item('FLAGS', commands)

dependencies.py

@@ -298,8 +298,26 @@ class Qt5Dependency(Dependency):
             self.modules.append(PkgConfigDependency('Qt5' + module, False))
         if len(self.modules) == 0:
             raise DependencyException('No Qt5 modules specified.')
+        self.find_exes()
+        
+    def find_exes(self):
         self.moc = ExternalProgram('moc')
         self.uic = ExternalProgram('uic')
+        # Moc and uic write their version strings to stderr.
+        # Moc returns a non-zero result when doing so.
+        # What kind of an idiot thought that was a good idea?
+        if self.moc.found():
+            mp = subprocess.Popen([self.moc.get_command(), '-v'],
+                                  stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+            moc_ver = mp.communicate()[1].decode()
+            if 'Qt 5' not in moc_ver:
+                raise DependencyException('Moc preprocessor is not for Qt 5.')
+        if self.uic.found():
+            up = subprocess.Popen([self.uic.get_command(), '-v'],
+                                  stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+            uic_ver = up.communicate()[1].decode()
+            if 'version 5.' not in uic_ver:
+                raise DependencyException('Uic compiler is not for Qt 5.')
 
     def get_version(self):
         return self.modules[0].get_version()
@@ -354,4 +372,5 @@ packages = {'boost': BoostDependency,
             'gtest': GTestDependency,
             'gmock': GMockDependency,
             'qt5': Qt5Dependency,
+            'Qt5': Qt5Dependency, # Qt people sure do love their upper case.
             }

test cases/frameworks/4 qt5/mainWindow.h

@@ -8,7 +8,7 @@ class MainWindow : public QMainWindow, private Ui_MainWindow {
     Q_OBJECT
 
 public:
-    MainWindow(QWidget *parent=nullptr);
+    MainWindow(QWidget *parent=0);
     ~MainWindow();
 
 private:

test cases/frameworks/4 qt5/meson.build

@@ -1,6 +1,6 @@
 project('qt5 build test', 'cxx')
 
-qt5dep = find_dep('qt5', modules : 'Gui', required : true)
+qt5dep = find_dep('qt5', modules : 'Widgets', required : true)
 
 q5exe = executable('qt5test',
 sources : ['main.cpp', 'mainWindow.cpp'],