+void Target::force_rebuild()
+{
+ if(!is_buildable())
+ throw logic_error("Target::force_rebuild");
+ mark_rebuild("Forced rebuild");
+}
+
+void Target::mark_rebuild(const string &reason)
+{
+ if(reason.empty())
+ throw invalid_argument("No reason given for rebuilding "+name);
+
+ state = REBUILD;
+ rebuild_reason = reason;
+
+ builder.get_logger().log("rebuild", format("Rebuilding %s: %s", name, reason));
+
+ signal_bubble_rebuild.emit();
+}
+
+void Target::prepare()
+{
+ if(state>PREPARING)
+ return;
+ if(state==PREPARING)
+ {
+ builder.problem((package ? package->get_name() : string()), "Dependency cycle detected at "+name);
+ return;
+ }
+
+ state = PREPARING;
+ find_dependencies();
+ if(tool)
+ {
+ if(FileTarget *tool_exe = tool->get_executable())
+ add_dependency(*tool_exe);
+ }
+
+ for(Dependencies::iterator i=depends.begin(); i!=depends.end(); ++i)
+ (*i)->prepare();
+
+ check_rebuild();
+ if(state==PREPARING)
+ state = UPTODATE;
+
+ for(Dependencies::iterator i=depends.begin(); i!=depends.end(); ++i)
+ (*i)->signal_bubble_rebuild.connect(sigc::mem_fun(this, &Target::check_rebuild));
+}
+
+Task *Target::build()
+{
+ if(!tool)
+ {
+ // This special case is needed for VirtualTargets
+ state = UPTODATE;
+ return 0;
+ }
+
+ Task *task = tool->run(*this);
+ task->signal_finished.connect(sigc::mem_fun(this, &Target::build_finished));
+ state = BUILDING;
+
+ return task;
+}