+ /** Finds dependencies for the target. Called during preparation. If the
+ target needs to recursively inspect its dependencies, it should prepare its
+ direct dependencies first. */
+ virtual void find_dependencies() { }
+
+public:
+ /// Returns the dependencies of the target, in the order they were added.
+ const Dependencies &get_dependencies() const { return depends; }
+
+ const Dependencies &get_transitive_dependencies() const { return trans_depends; }
+
+ /// Returns the side effects of the target.
+ const Dependencies &get_side_effects() const { return side_effects; }
+
+ /// Returns the primary target associated with a side effect target.
+ Target *get_primary_target() const { return primary_target; }
+
+ /** Tries to locate a target that will help getting this target built. If
+ all dependencies are up-to-date, returns this target. If there are no
+ targets ready to be built (maybe because they are being built right now),
+ returns 0. */
+ virtual Target *get_buildable_target();
+
+ /** If this target is a proxy for another (such as InstalledFile), return
+ that target. Otherwise, return the target itself. Implementors should call
+ the function recursively to find the final target. */
+ virtual Target *get_real_target() { return this; }
+
+ void set_tool(Tool &);
+
+ /** Returns the tool used to build the target. To actually build it, call
+ the build() function. */
+ const Tool *get_tool() const { return tool; }
+
+ /** Indicates if it's possible to build this target. */
+ bool is_buildable() const { return tool!=0; }
+
+ /** Indicates if this target needs rebuilding. Only makes sense after the
+ target has been prepared. */
+ bool needs_rebuild() const { return state>PREPARING && state<UPTODATE; }
+
+ /** Returns the reason for rebuilding this target. Only makes sense after
+ the target has been prepared. */
+ const std::string &get_rebuild_reason() const { return rebuild_reason; }
+
+ /** Forces rebuild of the target. */
+ void force_rebuild();
+
+protected:
+ /** Marks the target to be rebuilt and specified a reason for it. */
+ void mark_rebuild(const std::string &);
+
+ /** Checks if the target needs to be rebuilt and why. */
+ virtual void check_rebuild() = 0;
+
+public:
+ bool is_broken() const { return state==BROKEN; }
+
+ const std::list<std::string> &get_problems() const { return problems; }
+
+ /** Prepares the target by finding dependencies, recursively preparing them
+ and then checking whether rebuilding is needed. */
+ void prepare();
+
+ /** Invokes the associated Tool to build the target and returns the
+ resulting Task. The task must be started by the caller. */
+ virtual Task *build();
+
+protected:
+ /** Targets can override this to do additional setup on the Task. This is
+ also called on side effects, which normally do not get built by themselves. */
+ virtual void build(Task &) { }
+
+ /** Handler for Task::signal_finished. */
+ virtual void build_finished(bool);
+
+ virtual void modified() { }
+
+public:
+ /** Removes any results of building the target. */
+ virtual void clean() { }