diff options
Diffstat (limited to 'libbuild2/algorithm.cxx')
| -rw-r--r-- | libbuild2/algorithm.cxx | 68 |
1 files changed, 65 insertions, 3 deletions
diff --git a/libbuild2/algorithm.cxx b/libbuild2/algorithm.cxx index 9b6fd4e..cbf0495 100644 --- a/libbuild2/algorithm.cxx +++ b/libbuild2/algorithm.cxx @@ -2057,6 +2057,68 @@ namespace build2 return t.executed_state (a); } + bool + update_during_match (tracer& trace, action a, const target& t, timestamp ts) + { + assert (a == perform_update_id); + + // Note: this function is used to make sure header dependencies are up to + // date (and which is where it originated). + // + // There would normally be a lot of headers for every source file (think + // all the system headers) and just calling execute_direct() on all of + // them can get expensive. At the same time, most of these headers are + // existing files that we will never be updating (again, system headers, + // for example) and the rule that will match them is the fallback + // file_rule. That rule has an optimization: it returns noop_recipe (which + // causes the target state to be automatically set to unchanged) if the + // file is known to be up to date. So we do the update "smartly". + // + const path_target* pt (t.is_a<path_target> ()); + + if (pt == nullptr) + ts = timestamp_unknown; + + target_state os (t.matched_state (a)); + + if (os == target_state::unchanged) + { + if (ts == timestamp_unknown) + return false; + else + { + // We expect the timestamp to be known (i.e., existing file). + // + timestamp mt (pt->mtime ()); + assert (mt != timestamp_unknown); + return mt > ts; + } + } + else + { + // We only want to return true if our call to execute() actually caused + // an update. In particular, the target could already have been in + // target_state::changed because of the dynamic dependency extraction + // run for some other target. + // + // @@ MT perf: so we are going to switch the phase and execute for + // any generated header. + // + phase_switch ps (t.ctx, run_phase::execute); + target_state ns (execute_direct (a, t)); + + if (ns != os && ns != target_state::unchanged) + { + l6 ([&]{trace << "updated " << t + << "; old state " << os + << "; new state " << ns;}); + return true; + } + else + return ts != timestamp_unknown ? pt->newer (ts, ns) : false; + } + } + static inline void blank_adhoc_member (const target*&) { @@ -2065,7 +2127,7 @@ namespace build2 static inline void blank_adhoc_member (prerequisite_target& pt) { - if (pt.adhoc) + if (pt.adhoc ()) pt.target = nullptr; } @@ -2254,7 +2316,7 @@ namespace build2 // Should we compare the timestamp to this target's? // - if (!e && (p.adhoc || !ef || ef (pt, i))) + if (!e && (p.adhoc () || !ef || ef (pt, i))) { // If this is an mtime-based target, then compare timestamps. // @@ -2272,7 +2334,7 @@ namespace build2 } } - if (p.adhoc) + if (p.adhoc ()) p.target = nullptr; // Blank out. else { |