diff options
Diffstat (limited to 'libbuild2/rule.hxx')
| -rw-r--r-- | libbuild2/rule.hxx | 112 |
1 files changed, 94 insertions, 18 deletions
diff --git a/libbuild2/rule.hxx b/libbuild2/rule.hxx index 3eb7775..4f77432 100644 --- a/libbuild2/rule.hxx +++ b/libbuild2/rule.hxx @@ -22,7 +22,12 @@ namespace build2 // you need to modify some state (e.g., counters or some such), then make // sure things are MT-safe. // - // Note: match() is only called once but may not be followed by apply(). + // Note: match() could be called multiple times (so should be idempotent) + // and it may not be followed by apply(). + // + // The hint argument is the rule hint, if any, that was used to select this + // rule. While normally not factored into the match decision, a rule may + // "try harder" if a hint was specified (see cc::link_rule for an example). // // The match_extra argument (the type is defined in target.hxx) is used to // pass additional information that is only needed by some rule @@ -47,15 +52,45 @@ namespace build2 rule (const rule&) = delete; rule& operator= (const rule&) = delete; + + // Resolve a project-qualified target in a rule-specific manner. + // + // This is optional functionality that may be provided by some rules to + // facilitate immediate importation of certain target types. See the + // import machinery for details. The default implementation always returns + // NULL. + // + // Note that if this function returns a target, it should have the + // extension assigned so that as_name() returns a stable name. + // + virtual const target* + import (const prerequisite_key&, + const optional<string>& metadata, + const location&) const; + + // Sometimes we want to match only if another rule of ours would match + // another operation. For example, we would want our install rule to match + // only if our update rule also matches. + // + // Arranging this, however, is not a simple matter of calling the other + // rule's match(): we also have to take into account ad hoc recipes and + // rule hints for that operation. This helper performs all the necessary + // checks. Note: should only be called from match() (see + // target::find_hint() for details). Note also that ad hoc recipes are + // checked for hint_op, not action's operation. + // + bool + sub_match (const string& rule_name, operation_id hint_op, + action, target&, match_extra&) const; }; - // Simplified interface for rules that don't care about the extras. + // Simplified interface for rules that don't care about the hint or extras. // class LIBBUILD2_SYMEXPORT simple_rule: public rule { public: virtual bool - match (action, target&, const string& hint) const = 0; + match (action, target&) const = 0; virtual recipe apply (action, target&) const = 0; @@ -65,19 +100,31 @@ namespace build2 virtual recipe apply (action, target&, match_extra&) const override; + + // The simplified version of sub_match() above. + // + // Note that it calls the simplified match() directly rather than going + // through the original. + // + bool + sub_match (const string& rule_name, operation_id hint_op, + action, target&) const; }; // 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 simple_rule + // Note: this rule is "hot" because it matches every static source file and + // so we don't use simple_rule to avoid two extra virtual calls. + // + class LIBBUILD2_SYMEXPORT file_rule: public rule { public: virtual bool - match (action, target&, const string&) const override; + match (action, target&, const string&, match_extra&) const override; virtual recipe - apply (action, target&) const override; + apply (action, target&, match_extra&) const override; file_rule () {} @@ -89,7 +136,7 @@ namespace build2 { public: virtual bool - match (action, target&, const string&) const override; + match (action, target&) const override; virtual recipe apply (action, target&) const override; @@ -105,7 +152,7 @@ namespace build2 { public: virtual bool - match (action, target&, const string&) const override; + match (action, target&) const override; virtual recipe apply (action, target&) const override; @@ -132,7 +179,7 @@ namespace build2 { public: virtual bool - match (action, target&, const string&) const override; + match (action, target&) const override; virtual recipe apply (action, target&) const override; @@ -145,9 +192,14 @@ namespace build2 // // Used for both ad hoc pattern rules and ad hoc recipes. For recipes, it's // essentially a rule of one case. Note that when used as part of a pattern, - // the implementation cannot use the match_extra::buffer nor the target - // auxiliary data storage until the pattern's apply_*() calls have been - // made. + // the implementation cannot use the match_extra::data() facility nor the + // target auxiliary data storage until the pattern's apply_*() calls have + // been made. + // + // Note also that when used as part of a pattern, the rule is also register + // for the dist meta-operation (unless there is an explicit recipe for dist) + // in order to inject additional pattern prerequisites which may "pull" + // additional sources into the distribution. // // Note: not exported. // @@ -200,6 +252,16 @@ namespace build2 // The default implementation forwards to the pattern's match() if there // is a pattern and returns true otherwise. // + // Note also that in case of a member of a group-based target, match() is + // called on the group while apply() on the member (see match_rule() in + // algorithms.cxx for details). This means that match() may be called + // without having the target locked and as a result match() should (unless + // known to only match a non-group) treat the target as const and only + // rely on immutable information (type, name, etc) since the group could + // be matched concurrenly. This case can be detected by examining + // match_extra::locked (see adhoc_rule_regex_pattern::match() for a + // use-case). + // virtual bool match (action, target&, const string&, match_extra&) const override; @@ -214,8 +276,8 @@ namespace build2 // Implementation details. // public: - // The name in rule_match is used as a hint and as a name in diagnostics. - // The former does not apply to ad hoc recipes (but does apply to ad hoc + // The name in rule_match is used to match hints and in diagnostics. The + // former does not apply to ad hoc recipes (but does apply to ad hoc // rules). // const build2::rule_match rule_match; @@ -266,14 +328,28 @@ namespace build2 ~adhoc_rule_pattern (); public: + // Note: the adhoc_rule::match() restrictions apply here as well. + // virtual bool - match (action, target&, const string&, match_extra&) const = 0; + match (action, const target&, const string&, match_extra&) const = 0; + // Append additional group members. Note that this function should handle + // both ad hoc and explicit groups. + // virtual void - apply_adhoc_members (action, target&, match_extra&) const = 0; - + apply_group_members (action, target&, + const scope& base, + match_extra&) const = 0; + + // The implementation should append pattern prerequisites to + // t.prerequisite_targets[a] but not match. It should set bit 2 in + // prerequisite_target::include to indicate update=match and bit 3 + // to indicate update=unmatch. + // virtual void - apply_prerequisites (action, target&, match_extra&) const = 0; + apply_prerequisites (action, target&, + const scope& base, + match_extra&) const = 0; // Dump support. // |