BuildSystem: Fix move semantics of ParseGuard and related code

This avoids a spurious set of parsing started/finished signals.

Change-Id: I0c723f2a2ad679a5f6cffddf9f542ebc02192be8
Reviewed-by: Cristian Adam <cristian.adam@qt.io>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/cmakeprojectmanager/cmakebuildsystem.cpp

@@ -114,6 +114,7 @@ CMakeBuildSystem::~CMakeBuildSystem()
 
 bool CMakeBuildSystem::validateParsingContext(const ParsingContext &ctx)
 {
+    QTC_ASSERT(!m_currentContext.guard.guardsProject(), return false);
     return ctx.project && qobject_cast<CMakeBuildConfiguration *>(ctx.buildConfiguration);
 }
 

src/plugins/projectexplorer/buildsystem.cpp

@@ -95,6 +95,8 @@ void BuildSystem::triggerParsing()
 
     ParsingContext ctx(p->guardParsingRun(), p, bc, e, env);
 
+    QTC_ASSERT(ctx.guard.guardsProject(), return );
+
     if (validateParsingContext(ctx))
         parseProject(std::move(ctx));
 }

src/plugins/projectexplorer/buildsystem.h

@@ -65,8 +65,22 @@ protected:
 
         ParsingContext(const ParsingContext &other) = delete;
         ParsingContext &operator=(const ParsingContext &other) = delete;
-        ParsingContext(ParsingContext &&other) = default;
-        ParsingContext &operator=(ParsingContext &&other) = default;
+        ParsingContext(ParsingContext &&other)
+            : guard{std::move(other.guard)}
+            , project{std::move(other.project)}
+            , buildConfiguration{std::move(other.buildConfiguration)}
+            , expander{std::move(other.expander)}
+            , environment{std::move(other.environment)}
+        {}
+        ParsingContext &operator=(ParsingContext &&other)
+        {
+            guard = std::move(other.guard);
+            project = std::move(other.project);
+            buildConfiguration = std::move(other.buildConfiguration);
+            expander = std::move(other.expander);
+            environment = std::move(other.environment);
+            return *this;
+        }
 
         Project::ParseGuard guard;
 

src/plugins/projectexplorer/project.h

@@ -192,27 +192,29 @@ public:
             : ParseGuard(nullptr)
         {}
 
-        ~ParseGuard()
-        {
-            if (m_project)
-                m_project->emitParsingFinished(m_success);
-        }
+        ~ParseGuard() { release(); }
 
         void markAsSuccess() const { m_success = true; }
         bool isSuccess() const { return m_success; }
-        bool isNull() const { return !m_project; }
+        bool guardsProject() const { return m_project; }
 
         ParseGuard(const ParseGuard &other) = delete;
         ParseGuard &operator=(const ParseGuard &other) = delete;
         ParseGuard(ParseGuard &&other)
+            : m_project{std::move(other.m_project)}
+            , m_success{std::move(other.m_success)}
         {
-            std::swap(m_project, other.m_project);
-            std::swap(m_success, other.m_success);
+            // No need to release this as this is invalid anyway:-)
+            other.m_project = nullptr;
         }
         ParseGuard &operator=(ParseGuard &&other)
         {
-            std::swap(m_project, other.m_project);
-            std::swap(m_success, other.m_success);
+            release();
+
+            m_project = std::move(other.m_project);
+            m_success = std::move(other.m_success);
+
+            other.m_project = nullptr;
             return *this;
         }
 
@@ -220,8 +222,17 @@ public:
         ParseGuard(Project *p)
             : m_project(p)
         {
-            if (m_project)
+            if (m_project && !m_project->isParsing())
                 m_project->emitParsingStarted();
+            else
+                m_project = nullptr;
+        }
+
+        void release()
+        {
+            if (m_project)
+                m_project->emitParsingFinished(m_success);
+            m_project = nullptr;
         }
 
         Project *m_project = nullptr;