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Diffstat (limited to 'libbuild2/dyndep.hxx')
| -rw-r--r-- | libbuild2/dyndep.hxx | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/libbuild2/dyndep.hxx b/libbuild2/dyndep.hxx new file mode 100644 index 0000000..a0949c4 --- /dev/null +++ b/libbuild2/dyndep.hxx @@ -0,0 +1,304 @@ +// 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 newer 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 or was updated + // during match and issue diagnostics and fail otherwise (regardless of + // the fail flag). Pass 0 for pts_n if don't want the "was updated during + // match" part. + // + // 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 or was updated during match + // 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). Pass 0 for pts_n if don't want the "was updated during + // match" part. + // + // 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. + // + // It's possible the extension-to-target type mapping is ambiguous (for + // example, because both C and C++-language headers use the same .h + // extension). So this function can return multiple target types. + // + 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 and + // set its path. Return the target and an indication of whether it was + // made a member (can only be false if a filter is provided; see below). + // + // The file path must be absolute and normalized. Note that this function + // assumes that this member can only be matched via this group. The group + // type must have the target_type::flag::dyn_members flag. + // + // If specified, the group_filter function is called on the target before + // making it a group member, skipping it if this function returns false. + // Note that the filter is skipped if the target is newly inserted (the + // filter is meant to be used to skip duplicates). + // + using group_filter_func = bool (mtime_target& g, const file&); + + static pair<const file&, bool> + inject_group_member (action, const scope& base, mtime_target&, + path, + const target_type&, + const function<group_filter_func>& = nullptr); + + template <typename T> + static pair<const T&, bool> + inject_group_member (action a, const scope& bs, mtime_target& g, + path f, + const function<group_filter_func>& filter = nullptr) + { + auto p (inject_group_member (a, bs, g, move (f), T::static_type, filter)); + return pair<const T&, bool> (p.first.template as<T> (), p.second); + } + + // As above but the target type is determined using the map_extension + // function if specified, falling back to the fallback type if unable to + // (the what argument is used for diagnostics during this process). + // + static pair<const file&, bool> + inject_group_member (const char* what, + action, const scope& base, mtime_target& g, + path, + const function<map_extension_func>&, + const target_type& fallback, + const function<group_filter_func>& = nullptr); + + + // Find or insert a target file path as a target, make it a member of the + // specified ad hoc group unless it already is, and set its path. Return + // the target and an indication of whether it was added as a member. + // + // The file path must be absolute and normalized. Note that this function + // assumes that this target can only be known as a member of this group. + // + static pair<const file&, bool> + inject_adhoc_group_member (action, const scope& base, target& g, + path, + const target_type&); + + // As above but the target type is determined using the map_extension + // function if specified, falling back to the fallback type if unable to + // (the what argument is used for diagnostics during this process). + // + static pair<const file&, bool> + inject_adhoc_group_member (const char* what, + action, const scope& base, target& g, + path, + const function<map_extension_func>&, + const target_type& fallback); + }; +} + +#endif // LIBBUILD2_DYNDEP_HXX |