ProjectExplorer: Hide parts of BuildStep's QObject-ness from users

This lets the compiler catch issues like QTCREATORBUG-22818 and
saves visible casts on the user side.

Change-Id: I5a307a55364daa0bec039a4c38cc9827841ff9c1
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/android/androiddeployqtstep.cpp

@@ -193,7 +193,7 @@ bool AndroidDeployQtStep::init()
                            << "Min target API" << minTargetApi;
 
     // Try to re-use user-provided information from an earlier step of the same type.
-    auto bsl = qobject_cast<BuildStepList *>(parent());
+    BuildStepList *bsl = stepList();
     QTC_ASSERT(bsl, return false);
     auto androidDeployQtStep = bsl->firstOfType<AndroidDeployQtStep>();
     QTC_ASSERT(androidDeployQtStep, return false);

src/plugins/cmakeprojectmanager/cmakebuildstep.cpp

@@ -262,8 +262,9 @@ BuildStepConfigWidget *CMakeBuildStep::createConfigWidget()
 
 QString CMakeBuildStep::defaultBuildTarget() const
 {
-    const auto pc = qobject_cast<BuildStepList *>(parent());
-    const Core::Id parentId = pc ? pc->id() : Core::Id();
+    const BuildStepList *const bsl = stepList();
+    QTC_ASSERT(bsl, return {});
+    const Core::Id parentId = bsl->id();
     if (parentId == ProjectExplorer::Constants::BUILDSTEPS_CLEAN)
         return cleanTarget();
     if (parentId == ProjectExplorer::Constants::BUILDSTEPS_DEPLOY)

src/plugins/projectexplorer/buildstep.cpp

@@ -286,6 +286,11 @@ void BuildStep::setEnabled(bool b)
     emit enabledChanged();
 }
 
+BuildStepList *BuildStep::stepList() const
+{
+    return qobject_cast<BuildStepList *>(parent());
+}
+
 bool BuildStep::enabled() const
 {
     return m_enabled;

src/plugins/projectexplorer/buildstep.h

@@ -69,6 +69,8 @@ public:
     bool enabled() const;
     void setEnabled(bool b);
 
+    BuildStepList *stepList() const;
+
     BuildConfiguration *buildConfiguration() const;
     DeployConfiguration *deployConfiguration() const;
     ProjectConfiguration *projectConfiguration() const;
@@ -122,6 +124,8 @@ protected:
     bool isCanceled() const;
 
 private:
+    using ProjectConfiguration::parent;
+
     virtual void doRun() = 0;
     virtual void doCancel();
 

src/plugins/qmakeprojectmanager/qmakemakestep.cpp

@@ -80,7 +80,7 @@ bool QmakeMakeStep::init()
 
     // Ignore all but the first make step for a non-top-level build. See QTCREATORBUG-15794.
     m_ignoredNonTopLevelBuild = (bc->fileNodeBuild() || bc->subNodeBuild())
-            && static_cast<BuildStepList *>(parent())->firstOfType<QmakeMakeStep>() != this;
+            && stepList()->firstOfType<QmakeMakeStep>() != this;
 
     ProcessParameters *pp = processParameters();
     pp->setMacroExpander(bc->macroExpander());
@@ -173,8 +173,7 @@ bool QmakeMakeStep::init()
 
     // A user doing "make clean" indicates they want a proper rebuild, so make sure to really
     // execute qmake on the next build.
-    if (static_cast<BuildStepList *>(parent())->id()
-            == ProjectExplorer::Constants::BUILDSTEPS_CLEAN) {
+    if (stepList()->id() == ProjectExplorer::Constants::BUILDSTEPS_CLEAN) {
         const auto qmakeStep = bc->qmakeStep();
         if (qmakeStep)
             qmakeStep->setForced(true);

src/plugins/qmakeprojectmanager/qmakestep.cpp

@@ -442,7 +442,7 @@ void QMakeStep::setSeparateDebugInfo(bool enable)
 
 FilePath QMakeStep::makeCommand() const
 {
-    auto ms = qobject_cast<BuildStepList *>(parent())->firstOfType<MakeStep>();
+    auto ms = stepList()->firstOfType<MakeStep>();
     return ms ? ms->effectiveMakeCommand().executable() : FilePath();
 }