diff options
| -rw-r--r-- | libbuild2/algorithm.cxx | 259 |
1 files changed, 143 insertions, 116 deletions
diff --git a/libbuild2/algorithm.cxx b/libbuild2/algorithm.cxx index 9e4d77a..8b1d2fc 100644 --- a/libbuild2/algorithm.cxx +++ b/libbuild2/algorithm.cxx @@ -447,165 +447,192 @@ namespace build2 meta_operation_id mo (a.meta_operation ()); operation_id o (a.inner () ? a.operation () : a.outer_operation ()); - const string& hint (t.find_hint (o)); // MT-safe (target locked). - - for (auto tt (&t.type ()); tt != nullptr; tt = tt->base) - { - // Search scopes outwards, stopping at the project root. - // - for (const scope* s (&bs); - s != nullptr; - s = s->root () ? &s->global_scope () : s->parent_scope ()) + // Our hint semantics applies regardless of the meta-operation. This works + // reasonably well except for the default/fallback rules provided by some + // meta-operations (e.g., dist, config), which naturally do not match the + // hint. + // + // The way we solve this problem is by trying a hint-less match as a + // fallback for non-perform meta-operations. @@ Ideally we would want to + // only consider such default/fallback rules, which we may do in the + // future (we could just decorate their names with some special marker, + // e.g., `dist.file.*` but that would be visible in diagnostics). + // + // It seems the only potential problem with this approach is the inability + // by the user to specify the hint for this specific meta-operation (e.g., + // to resolve an ambiguity between two rules or override a matched rule), + // which seems quite remote at the moment. Maybe/later we can invent a + // syntax for that. + // + const string* hint; + for (bool retry (false);; retry = true) + { + hint = retry + ? &empty_string + : &t.find_hint (o); // MT-safe (target locked). + + for (auto tt (&t.type ()); tt != nullptr; tt = tt->base) { - const operation_rule_map* om (s->rules[mo]); - - if (om == nullptr) - continue; // No entry for this meta-operation id. - - // First try the map for the actual operation. If that doesn't yeld - // anything, try the wildcard map. + // Search scopes outwards, stopping at the project root. For retry + // only look in the root and global scopes. // - for (operation_id oi (o), oip (o); oip != 0; oip = oi, oi = 0) + for (const scope* s (retry ? bs.root_scope () : &bs); + s != nullptr; + s = s->root () ? &s->global_scope () : s->parent_scope ()) { - const target_type_rule_map* ttm ((*om)[oi]); - - if (ttm == nullptr) - continue; // No entry for this operation id. - - if (ttm->empty ()) - continue; // Empty map for this operation id. + const operation_rule_map* om (s->rules[mo]); - auto i (ttm->find (tt)); + if (om == nullptr) + continue; // No entry for this meta-operation id. - if (i == ttm->end () || i->second.empty ()) - continue; // No rules registered for this target type. - - const auto& rules (i->second); // Name map. - - // Filter against the hint, if any. + // First try the map for the actual operation. If that doesn't yeld + // anything, try the wildcard map. // - auto rs (hint.empty () - ? make_pair (rules.begin (), rules.end ()) - : rules.find_sub (hint)); - - for (auto i (rs.first); i != rs.second; ++i) + for (operation_id oi (o), oip (o); oip != 0; oip = oi, oi = 0) { - const rule_match* r (&*i); + const target_type_rule_map* ttm ((*om)[oi]); - // In a somewhat hackish way we reuse operation wildcards to plumb - // the ad hoc rule's reverse operation fallback logic. - // - // The difficulty is two-fold: - // - // 1. It's difficult to add the fallback flag to the rule map - // because of rule_match which is used throughout. - // - // 2. Even if we could do that, we pass the reverse action to - // reverse_fallback() rather than it returning (a list) of - // reverse actions, which would be necessary to register them. - // - using fallback_rule = adhoc_rule_pattern::fallback_rule; + if (ttm == nullptr) + continue; // No entry for this operation id. - auto find_fallback = [mo, o, tt] (const fallback_rule& fr) - -> const rule_match* - { - for (const shared_ptr<adhoc_rule>& ar: fr.rules) - if (ar->reverse_fallback (action (mo, o), *tt)) - return &ar->rule_match; + if (ttm->empty ()) + continue; // Empty map for this operation id. - return nullptr; - }; + auto i (ttm->find (tt)); - if (oi == 0) - { - if (auto* fr = - dynamic_cast<const fallback_rule*> (&r->second.get ())) - { - if ((r = find_fallback (*fr)) == nullptr) - continue; - } - } + if (i == ttm->end () || i->second.empty ()) + continue; // No rules registered for this target type. - const string& n (r->first); - const rule& ru (r->second); + const auto& rules (i->second); // Name map. - if (&ru == skip) - continue; + // Filter against the hint, if any. + // + auto rs (hint->empty () + ? make_pair (rules.begin (), rules.end ()) + : rules.find_sub (*hint)); - me.init (oi == 0 /* fallback */); + for (auto i (rs.first); i != rs.second; ++i) { - auto df = make_diag_frame ( - [a, &t, &n](const diag_record& dr) - { - if (verb != 0) - dr << info << "while matching rule " << n << " to " - << diag_do (a, t); - }); + const rule_match* r (&*i); - if (!ru.match (a, t, hint, me)) - continue; - } + // In a somewhat hackish way we reuse operation wildcards to + // plumb the ad hoc rule's reverse operation fallback logic. + // + // The difficulty is two-fold: + // + // 1. It's difficult to add the fallback flag to the rule map + // because of rule_match which is used throughout. + // + // 2. Even if we could do that, we pass the reverse action to + // reverse_fallback() rather than it returning (a list) of + // reverse actions, which would be necessary to register them. + // + using fallback_rule = adhoc_rule_pattern::fallback_rule; - // Do the ambiguity test. - // - bool ambig (false); + auto find_fallback = [mo, o, tt] (const fallback_rule& fr) + -> const rule_match* + { + for (const shared_ptr<adhoc_rule>& ar: fr.rules) + if (ar->reverse_fallback (action (mo, o), *tt)) + return &ar->rule_match; - diag_record dr; - for (++i; i != rs.second; ++i) - { - const rule_match* r1 (&*i); + return nullptr; + }; if (oi == 0) { if (auto* fr = - dynamic_cast<const fallback_rule*> (&r1->second.get ())) + dynamic_cast<const fallback_rule*> (&r->second.get ())) { - if ((r1 = find_fallback (*fr)) == nullptr) + if ((r = find_fallback (*fr)) == nullptr) continue; } } - const string& n1 (r1->first); - const rule& ru1 (r1->second); + const string& n (r->first); + const rule& ru (r->second); + if (&ru == skip) + continue; + + me.init (oi == 0 /* fallback */); { auto df = make_diag_frame ( - [a, &t, &n1](const diag_record& dr) + [a, &t, &n](const diag_record& dr) { if (verb != 0) - dr << info << "while matching rule " << n1 << " to " + dr << info << "while matching rule " << n << " to " << diag_do (a, t); }); - // @@ TODO: this makes target state in match() undetermined - // so need to fortify rules that modify anything in match - // to clear things. - // - // @@ Can't we temporarily swap things out in target? - // - match_extra me1; - me1.init (oi == 0); - if (!ru1.match (a, t, hint, me1)) + if (!ru.match (a, t, *hint, me)) continue; } - if (!ambig) + // Do the ambiguity test. + // + bool ambig (false); + + diag_record dr; + for (++i; i != rs.second; ++i) { - dr << fail << "multiple rules matching " << diag_doing (a, t) - << info << "rule " << n << " matches"; - ambig = true; + const rule_match* r1 (&*i); + + if (oi == 0) + { + if (auto* fr = + dynamic_cast<const fallback_rule*> (&r1->second.get ())) + { + if ((r1 = find_fallback (*fr)) == nullptr) + continue; + } + } + + const string& n1 (r1->first); + const rule& ru1 (r1->second); + + { + auto df = make_diag_frame ( + [a, &t, &n1](const diag_record& dr) + { + if (verb != 0) + dr << info << "while matching rule " << n1 << " to " + << diag_do (a, t); + }); + + // @@ TODO: this makes target state in match() undetermined + // so need to fortify rules that modify anything in match + // to clear things. + // + // @@ Can't we temporarily swap things out in target? + // + match_extra me1; + me1.init (oi == 0); + if (!ru1.match (a, t, *hint, me1)) + continue; + } + + if (!ambig) + { + dr << fail << "multiple rules matching " << diag_doing (a, t) + << info << "rule " << n << " matches"; + ambig = true; + } + + dr << info << "rule " << n1 << " also matches"; } - dr << info << "rule " << n1 << " also matches"; + if (!ambig) + return r; + else + dr << info << "use rule hint to disambiguate this match"; } - - if (!ambig) - return r; - else - dr << info << "use rule hint to disambiguate this match"; } } } + + if (mo == perform_id || hint->empty () || retry) + break; } me.free (); @@ -614,10 +641,10 @@ namespace build2 { diag_record dr (fail); - if (hint.empty ()) + if (hint->empty ()) dr << "no rule to "; else - dr << "no rule with hint " << hint << " to "; + dr << "no rule with hint " << *hint << " to "; dr << diag_do (a, t); |