diff options
Diffstat (limited to 'libbuild2/rule.hxx')
| -rw-r--r-- | libbuild2/rule.hxx | 44 |
1 files changed, 36 insertions, 8 deletions
diff --git a/libbuild2/rule.hxx b/libbuild2/rule.hxx index 8390ea7..298ed6b 100644 --- a/libbuild2/rule.hxx +++ b/libbuild2/rule.hxx @@ -16,20 +16,30 @@ namespace build2 { + // Rule interface (see also simple_rule below for a simplified version). + // // Once a rule is registered (for a scope), it is treated as immutable. If // you need to modify some state (e.g., counters or some such), then make - // sure it is MT-safe. + // sure things are MT-safe. // // Note: match() is only called once but may not be followed by apply(). // class LIBBUILD2_SYMEXPORT rule { public: + // The match_extra argument is used to pass additional information that is + // only needed by some rule implementations. It is also a way for us to + // later pass more information without breaking source compatibility. + // + struct match_extra + { + }; + virtual bool - match (action, target&, const string& hint) const = 0; + match (action, target&, const string& hint, match_extra&) const = 0; virtual recipe - apply (action, target&) const = 0; + apply (action, target&, match_extra&) const = 0; rule () = default; @@ -40,10 +50,28 @@ namespace build2 rule& operator= (const rule&) = delete; }; + // Simplified interface for rules that don't care about the extras. + // + class LIBBUILD2_SYMEXPORT simple_rule: public rule + { + public: + virtual bool + match (action, target&, const string& hint) const = 0; + + virtual recipe + apply (action, target&) const = 0; + + virtual bool + match (action, target&, const string&, match_extra&) const override; + + virtual recipe + apply (action, target&, match_extra&) const override; + }; + // Fallback rule that only matches if the file exists. It will also match // an mtime_target provided it has a set timestamp. // - class LIBBUILD2_SYMEXPORT file_rule: public rule + class LIBBUILD2_SYMEXPORT file_rule: public simple_rule { public: virtual bool @@ -56,7 +84,7 @@ namespace build2 static const file_rule instance; }; - class LIBBUILD2_SYMEXPORT alias_rule: public rule + class LIBBUILD2_SYMEXPORT alias_rule: public simple_rule { public: virtual bool @@ -72,7 +100,7 @@ namespace build2 // Note that this rule ignores the dry_run flag; see mkdir() in filesystem // for the rationale. // - class LIBBUILD2_SYMEXPORT fsdir_rule: public rule + class LIBBUILD2_SYMEXPORT fsdir_rule: public simple_rule { public: virtual bool @@ -99,7 +127,7 @@ namespace build2 // Fallback rule that always matches and does nothing. // - class LIBBUILD2_SYMEXPORT noop_rule: public rule + class LIBBUILD2_SYMEXPORT noop_rule: public simple_rule { public: virtual bool @@ -116,7 +144,7 @@ namespace build2 // // Note: not exported. // - class adhoc_rule: public rule + class adhoc_rule: public simple_rule { public: location_value loc; // Buildfile location of the recipe. |