// file : libbuild2/dyndep.hxx -*- C++ -*- // license : MIT; see accompanying LICENSE file #ifndef LIBBUILD2_DYNDEP_HXX #define LIBBUILD2_DYNDEP_HXX #include <libbuild2/types.hxx> #include <libbuild2/forward.hxx> #include <libbuild2/utility.hxx> #include <libbuild2/action.hxx> #include <libbuild2/target.hxx> #include <libbuild2/export.hxx> // Additional functionality that is normally only useful for implementing // rules with dynamic dependencies (usually prerequisites, but also target // group members). // namespace build2 { class LIBBUILD2_SYMEXPORT dyndep_rule { public: // Update the target during the match phase. Return true if the target has // changed or, if the passed timestamp is not timestamp_unknown, it is // older than the target. // // Note that such a target must still be updated during the execute phase // in order to keep the dependency counts straight. // static bool update (tracer&, action, const target&, timestamp); // Update and add to the list of prerequisite targets a prerequisite file // target. // // Return the indication of whether it has changed or, if the passed // timestamp is not timestamp_unknown, is older than this timestamp. If // the prerequisite target does not exists nor can be generated (no rule), // then issue diagnostics and fail if the fail argument is true and return // nullopt otherwise. // // If adhoc is true, then add it as ad hoc to prerequisite targets. At // first it may seem like such dynamic prerequisites should always be ad // hoc. But on the other hand, taking headers as an example, if the same // header is listed as a static prerequisite, it will most definitely not // going to be ad hoc. So we leave it to the caller to make this decision. // Similarly, the data argument is passed to the prerequisite_target ctor. // static optional<bool> inject_file (tracer&, const char* what, action, target&, const file& prerequiste, timestamp, bool fail, bool adhoc = false, uintptr_t data = 0); // As above but verify the file is matched with noop_recipe and issue // diagnostics and fail otherwise (regardless of the fail flag). // // This version (together with verify_existing_file() below) is primarily // useful for handling dynamic dependencies that are produced as a // byproduct of recipe execution (and thus must have all the generated // prerequisites specified statically). // // Note that this function expects all the static prerequisites of the // target to already be matched and their number passed in pts_n. // static optional<bool> inject_existing_file (tracer&, const char* what, action, target&, size_t pts_n, const file& prerequiste, timestamp, bool fail, bool adhoc = false, uintptr_t data = 0); // Verify the file is matched with noop_recipe and issue diagnostics and // fail otherwise. If the file is not matched, then fail if the target is // not implied (that is, declared in a buildfile). // // Note: can only be called in the execute phase. // static void verify_existing_file (tracer&, const char* what, action, const target&, size_t pts_n, const file& prerequiste); // Reverse-lookup target type(s) from file name/extension. // // If the list of base target types is specified, then only these types // and those derived from them are considered. Otherwise, any file-based // type is considered but not the file type itself. // static small_vector<const target_type*, 2> map_extension (const scope& base, const string& name, const string& ext, const target_type* const* bases); // Mapping of inclusion prefixes (e.g., foo in #include <foo/bar>) for // auto-generated files to inclusion search paths (e.g. -I) where they // will be generated. // // We are using a prefix map of directories (dir_path_map) instead of just // a map in order to also cover sub-paths (e.g., #include <foo/more/bar> // if we continue with the example). Specifically, we need to make sure we // don't treat foobar as a sub-directory of foo. // // The priority is used to decide who should override whom. Lesser values // are considered higher priority. Note that we allow multiple prefixless // mapping (where priority is used to determine the order). For details, // see append_prefix(). // // Note that the keys should be normalized. // struct prefix_value { dir_path directory; size_t priority; }; using prefix_map = dir_path_multimap<prefix_value>; // Add the specified absolute and normalized inclusion search path into // the prefix map of the specified target. // static void append_prefix (tracer&, prefix_map&, const target&, dir_path); // Mapping of src inclusion search paths to the corresponding out paths // for auto-generated files re-mapping. See cc::extract_headers() for // background. // // Note that we use path_map instead of dir_path_map to allow searching // using path (file path). // using srcout_map = path_map<dir_path>; class LIBBUILD2_SYMEXPORT srcout_builder { public: srcout_builder (context& ctx, srcout_map& map): ctx_ (ctx), map_ (map) {} // Process next -I path. Return true if an entry was added to the map, // in which case the passed path is moved from. // bool next (dir_path&&); // Skip the previously cached first half. // void skip () { prev_ = nullptr; } private: context& ctx_; srcout_map& map_; // Previous -I's innermost scope if out_base plus the difference between // the scope path and the -I path (normally empty). // const scope* prev_ = nullptr; dir_path diff_; }; // Find or insert a prerequisite file path as a target. If the path is // relative, then assume this is a non-existent generated file. // // Depending on the cache flag, the path is assumed to either have come // from the depdb cache or from the compiler run. If normalized is true, // then assume the absolute path is already normalized. // // Return the file target and an indication of whether it was remapped or // NULL if the file does not exist and cannot be generated. The passed by // reference file path is guaranteed to still be valid but might have been // adjusted (e.g., completed, normalized, remapped, etc). If the result is // not NULL, then it is the absolute and normalized path to the actual // file. If the result is NULL, then it can be used in diagnostics to // identify the origial file path. // // The map_extension function is used to reverse-map a file extension to // the target type. The fallback target type is used if it's NULL or // didn't return anything but only in situations where we are sure the // file is or should be there (see the implementation for details). // // The prefix map function is only called if this is a non-existent // generated file (so it can be initialized lazily). If it's NULL, then // generated files will not be supported. The srcout map is only consulted // if cache is false to re-map generated files (so its initialization can // be delayed until the call with cache=false). // using map_extension_func = small_vector<const target_type*, 2> ( const scope& base, const string& name, const string& ext); using prefix_map_func = const prefix_map& ( action, const scope& base, const target&); static pair<const file*, bool> enter_file (tracer&, const char* what, action, const scope& base, target&, path& prerequisite, bool cache, bool normalized, const function<map_extension_func>&, const target_type& fallback, const function<prefix_map_func>& = nullptr, const srcout_map& = {}); // As above but do not insert the target if it doesn't already exist. This // function also returns NULL if the target exists but is dynamic (that // is, not real or implied), unless the dynamic argument is true. // static pair<const file*, bool> find_file (tracer&, const char* what, action, const scope& base, const target&, path& prerequisite, bool cache, bool normalized, bool dynamic, const function<map_extension_func>&, const target_type& fallback, const function<prefix_map_func>& = nullptr, const srcout_map& = {}); // Find or insert a target file path as a target of the specified type, // make it a member of the specified (non-ad hoc) mtime target group, // set its path, and match it with group_recipe. // // The file path must be absolute and normalized. Note that this function // assumes that this member can only be matched via this group. // // Note: we can split this function into {enter,match}_group_member() // if necessary. // static const file& inject_group_member (action, const scope& base, mtime_target&, path, const target_type&); template <typename T> static const T& inject_group_member (action a, const scope& bs, mtime_target& g, path p) { return inject_group_member ( a, bs, g, move (p), T::static_type).template as<T> (); } }; } #endif // LIBBUILD2_DYNDEP_HXX