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diff --git a/build2/algorithm.hxx b/build2/algorithm.hxx new file mode 100644 index 0000000..36e5a92 --- /dev/null +++ b/build2/algorithm.hxx @@ -0,0 +1,437 @@ +// file : build2/algorithm.hxx -*- C++ -*- +// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd +// license : MIT; see accompanying LICENSE file + +#ifndef BUILD2_ALGORITHM_HXX +#define BUILD2_ALGORITHM_HXX + +#include <build2/types.hxx> +#include <build2/utility.hxx> + +#include <build2/target.hxx> +#include <build2/operation.hxx> + +namespace build2 +{ + class scope; + class prerequisite; + class prerequisite_key; + + // The default prerequisite search implementation. It first calls the + // prerequisite-type-specific search function. If that doesn't yeld + // anything, it creates a new target. + // + const target& + search (const target&, const prerequisite&); + + // As above but specify the prerequisite to search as a key. + // + const target& + search (const target&, const prerequisite_key&); + + // Uniform search interface for prerequisite/prerequisite_member. + // + inline const target& + search (const target& t, const prerequisite_member& p) {return p.search (t);} + + // As above but override the target type. Useful for searching for + // target group members where we need to search for a different + // target type. + // + const target& + search (const target&, const target_type&, const prerequisite_key&); + + // As above but specify the prerequisite to search as individual key + // components. Scope can be NULL if the directory is absolute. + // + const target& + search (const target&, + const target_type& type, + const dir_path& dir, + const dir_path& out, + const string& name, + const string* ext = nullptr, // NULL means unspecified. + const scope* = nullptr, // NULL means dir is absolute. + const optional<string>& proj = nullopt); + + // As above but specify the target type as template argument. + // + template <typename T> + const T& + search (const target&, + const dir_path& dir, + const dir_path& out, + const string& name, + const string* ext = nullptr, + const scope* = nullptr); + + // Search for a target identified by the name. The semantics is "as if" we + // first created a prerequisite based on this name in exactly the same way + // as the parser would and then searched based on this prerequisite. + // + const target& + search (const target&, name, const scope&); + + // As above but only search for an already existing target. Unlike the above + // version, this one can be called during the execute phase. Return NULL for + // unknown target types. + // + const target* + search_existing (const name&, + const scope&, + const dir_path& out = dir_path ()); + + // Target match lock: a non-const target reference as well as the + // target::offset_* state that has already been "achieved". + // + struct target_lock + { + using target_type = build2::target; + + target_type* target = nullptr; + size_t offset = 0; + + explicit operator bool () const {return target != nullptr;} + + void unlock (); + target_type* release (); + + target_lock () = default; + + target_lock (target_lock&&); + target_lock& operator= (target_lock&&); + + // Implementation details. + // + target_lock (const target_lock&) = delete; + target_lock& operator= (const target_lock&) = delete; + + target_lock (target_type* t, size_t o): target (t), offset (o) {} + ~target_lock (); + }; + + // If the target is already applied (for this action ) or executed, then no + // lock is acquired. Otherwise, the target must not yet be matched for this + // action. + // + // @@ MT fuzzy: what if it is already in the desired state, why assert? + // Currently we only use it with match_recipe(). + // + target_lock + lock (action, const target&); + + // Match and apply a rule to the action/target with ambiguity detection. + // Increment the target's dependents count, which means that you should call + // this function with the intent to also call execute(). Return the target + // state translating target_state::failed to the failed exception unless + // instructed otherwise. + // + // The unmatch argument allows optimizations that avoid calling execute(). + // If it is unmatch::unchanged then only unmatch the target if it is known + // to be unchanged after match. If it is unmatch::safe, then unmatch the + // target if it is safe (this includes unchanged or if we know that someone + // else will execute this target). Return true if unmatch succeeded. Always + // throw if failed. + // + enum class unmatch {none, unchanged, safe}; + + target_state + match (action, const target&, bool fail = true); + + bool + match (action, const target&, unmatch); + + // Start asynchronous match. Return target_state::postponed if the + // asynchrounous operation has been started and target_state::busy if the + // target has already been busy. Regardless of the result, match() must be + // called in order to complete the operation (except target_state::failed). + // + // If fail is false, then return target_state::failed if the target match + // failed. Otherwise, throw the failed exception if keep_going is false and + // return target_state::failed otherwise. + // + target_state + match_async (action, const target&, + size_t start_count, atomic_count& task_count, + bool fail = true); + + // Match by specifying the recipe directly. The target must be locked. + // + void + match_recipe (target_lock&, recipe); + + // Match a "delegate rule" from withing another rules' apply() function + // avoiding recursive matches (thus the third argument). Return recipe and + // recipe action (if any). Unless fail is false, fail if not rule is found. + // Otherwise return empty recipe. Note that unlike match(), this function + // does not increment the dependents count. See also the companion + // execute_delegate(). + // + pair<recipe, action> + match_delegate (action, target&, const rule&, bool fail = true); + + // The standard prerequisite search and match implementations. They call + // search() and then match() for each prerequisite in a loop omitting out of + // project prerequisites for the clean operation. If this target is a member + // of a group, then they first do this to the group's prerequisites. + // + void + match_prerequisites (action, target&); + + // If we are cleaning, this function doesn't go into group members, + // as an optimization (the group should clean everything up). + // + void + match_prerequisite_members (action, target&); + + // As above but omit prerequisites that are not in the specified scope. + // + void + match_prerequisites (action, target&, const scope&); + + void + match_prerequisite_members (action, target&, const scope&); + + // Match (already searched) members of a group or similar prerequisite-like + // dependencies. Similar in semantics to match_prerequisites(). + // + void + match_members (action, target&, const target*[], size_t); + + template <size_t N> + inline void + match_members (action a, target& t, const target* (&ts)[N]) + { + match_members (a, t, ts, N); + } + + inline void + match_members (action a, target& t, vector<const target*>& ts, size_t start) + { + match_members (a, t, ts.data () + start, ts.size () - start); + } + + // Unless already available, match, and, if necessary, execute the group + // in order to obtain its members list. Note that even after that the + // member's list might still not be available (e.g., if some wildcard/ + // fallback rule matched). + // + group_view + resolve_group_members (action, const target&); + + // Inject dependency on the target's directory fsdir{}, unless it is in the + // src tree or is outside of any project (say, for example, an installation + // directory). If the parent argument is true, then inject the parent + // directory of a target that is itself a directory (name is empty). Return + // the injected target or NULL. Normally this function is called from the + // rule's apply() function. + // + const fsdir* + inject_fsdir (action, target&, bool parent = true); + + // Execute the action on target, assuming a rule has been matched and the + // recipe for this action has been set. This is the synchrounous executor + // implementation (but may still return target_state::busy if the target + // is already being executed). Decrements the dependents count. + // + // Note: does not translate target_state::failed to the failed exception. + // + target_state + execute (action, const target&); + + // As above but start asynchronous execution. Return target_state::unknown + // if the asynchrounous execution has been started and target_state::busy if + // the target has already been busy. + // + // If fail is false, then return target_state::failed if the target match + // failed. Otherwise, throw the failed exception if keep_going is false and + // return target_state::failed otherwise. + // + target_state + execute_async (action, const target&, + size_t start_count, atomic_count& task_count, + bool fail = true); + + // Execute the recipe obtained with match_delegate(). Note that the target's + // state is neither checked nor updated by this function. In other words, + // the appropriate usage is to call this function from another recipe and to + // factor the obtained state into the one returned. + // + target_state + execute_delegate (const recipe&, action, const target&); + + // A special version of the above that should be used for "direct" and "now" + // execution, that is, side-stepping the normal target-prerequisite + // relationship (so no dependents count is decremented) and execution order + // (so this function never returns the postponed target state). + // + // Note: waits for the completion if the target is busy and translates + // target_state::failed to the failed exception. + // + target_state + execute_direct (action, const target&); + + // The default prerequisite execute implementation. Call execute_async() on + // each non-ignored (non-NULL) prerequisite target in a loop and then wait + // for their completion. Return target_state::changed if any of them were + // changed and target_state::unchanged otherwise. If a prerequisite's + // execution is postponed, then set its pointer in prerequisite_targets to + // NULL (since its state cannot be queried MT-safely). + // + // Note that this function can be used as a recipe. + // + target_state + straight_execute_prerequisites (action, const target&); + + // As above but iterates over the prerequisites in reverse. + // + target_state + reverse_execute_prerequisites (action, const target&); + + // Call straight or reverse depending on the current mode. + // + target_state + execute_prerequisites (action, const target&); + + // A version of the above that also determines whether the action needs to + // be executed on the target based on the passed timestamp and filter. + // + // The filter is passed each prerequisite target and is expected to signal + // which ones should be used for timestamp comparison. If the filter is + // NULL, then all the prerequisites are used. + // + // Note that the return value is an optional target state. If the target + // needs updating, then the value absent. Otherwise it is the state that + // should be returned. This is used to handle the situation where some + // prerequisites were updated but no update of the target is necessary. In + // this case we still signal that the target was (conceptually, but not + // physically) changed. This is important both to propagate the fact that + // some work has been done and to also allow our dependents to detect this + // case if they are up to something tricky (like recursively linking liba{} + // prerequisites). + // + // Note that because we use mtime, this function should normally only be + // used in the perform_update action (which is straight). + // + using prerequisite_filter = function<bool (const target&)>; + + optional<target_state> + execute_prerequisites (action, const target&, + const timestamp&, + const prerequisite_filter& = nullptr); + + // Another version of the above that does two extra things for the caller: + // it determines whether the action needs to be executed on the target based + // on the passed timestamp and finds a prerequisite of the specified type + // (e.g., a source file). If there are multiple prerequisites of this type, + // then the first is returned (this can become important if additional + // prerequisites of the same type may get injected). + // + template <typename T> + pair<optional<target_state>, const T&> + execute_prerequisites (action, const target&, + const timestamp&, + const prerequisite_filter& = nullptr); + + pair<optional<target_state>, const target&> + execute_prerequisites (const target_type&, + action, const target&, + const timestamp&, + const prerequisite_filter& = nullptr); + + template <typename T> + pair<optional<target_state>, const T&> + execute_prerequisites (const target_type&, + action, const target&, + const timestamp&, + const prerequisite_filter& = nullptr); + + // Execute members of a group or similar prerequisite-like dependencies. + // Similar in semantics to execute_prerequisites(). + // + target_state + straight_execute_members (action, const target&, const target*[], size_t); + + target_state + reverse_execute_members (action, const target&, const target*[], size_t); + + // Call straight or reverse depending on the current mode. + // + target_state + execute_members (action, const target&, const target*[], size_t); + + template <size_t N> + inline target_state + straight_execute_members (action a, const target& t, const target* (&ts)[N]) + { + return straight_execute_members (a, t, ts, N); + } + + template <size_t N> + inline target_state + reverse_execute_members (action a, const target& t, const target* (&ts)[N]) + { + return reverse_execute_members (a, t, ts, N); + } + + template <size_t N> + inline target_state + execute_members (action a, const target& t, const target* (&ts)[N]) + { + return execute_members (a, t, ts, N); + } + + // Return noop_recipe instead of using this function directly. + // + target_state + noop_action (action, const target&); + + // Default action implementation which forwards to the prerequisites. + // Use default_recipe instead of using this function directly. + // + target_state + default_action (action, const target&); + + // Standard perform(clean) action implementation for the file target + // (or derived). + // + target_state + perform_clean (action, const target&); + + // As above, but also removes the auxiliary dependency database (.d file). + // + target_state + perform_clean_depdb (action, const target&); + + // Helper for custom perform(clean) implementations that cleans extra files + // and directories (recursively) specified as a list of either absolute + // paths or "path derivation directives". The directive string can be NULL, + // or empty in which case it is ignored. If the last character in a + // directive is '/', then the resulting path is treated as a directory + // rather than a file. The directive can start with zero or more '-' + // characters which indicate the number of extensions that should be + // stripped before the new extension (if any) is added (so if you want to + // strip the extension, specify just "-"). For example: + // + // clean_extra (a, t, {".d", ".dlls/", "-.dll"}); + // + // The extra files/directories are removed first in the specified order + // followed by the ad hoc group member, then target itself, and, finally, + // the prerequisites in the reverse order. + // + // You can also clean extra files derived from adhoc group members. + // + target_state + clean_extra (action, const file&, + initializer_list<initializer_list<const char*>> extra); + + inline target_state + clean_extra (action a, const file& f, initializer_list<const char*> extra) + { + return clean_extra (a, f, {extra}); + } +} + +#include <build2/algorithm.ixx> + +#endif // BUILD2_ALGORITHM_HXX |