diff options
Diffstat (limited to 'libbuild2/dyndep.hxx')
| -rw-r--r-- | libbuild2/dyndep.hxx | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/libbuild2/dyndep.hxx b/libbuild2/dyndep.hxx new file mode 100644 index 0000000..3ba0c09 --- /dev/null +++ b/libbuild2/dyndep.hxx @@ -0,0 +1,168 @@ +// 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. +// +namespace build2 +{ + class LIBBUILD2_SYMEXPORT dyndep_rule + { + public: + // Update the target during the match phase. Return true if it has changed + // or if the passed timestamp is not timestamp_unknown and is older than + // the target. + // + 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. + // + static optional<bool> + inject_file (tracer&, const char* what, + action, target&, + const file& prerequiste, + timestamp, + bool fail); + + // 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_; + }; + + // Enter a prerequisite file as a target. If the path is relative, then + // assume this 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. In the former case + // assume the path is already normalized unless the normalize flag is + // true. + // + // Return the file target and an indication of whether it was remapped or + // NULL if the file does not exist and cannot be generated. In the latter + // case the passed file path is guaranteed to still be valid but might + // have been adjusted (e.g., normalized, etc). + // + // 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 (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 norm, + const function<map_extension_func>&, + const target_type& fallback, + const function<prefix_map_func>&, + const srcout_map&); + }; +} + +#endif // LIBBUILD2_DYNDEP_HXX |