Track which reasons need changes

11 files changed, 192 insertions, 22 deletions

diff --git a/paludis/resolver/Makefile.am b/paludis/resolver/Makefile.am
index d7034faf7..2116c8df4 100644
--- a/paludis/resolver/Makefile.am
+++ b/paludis/resolver/Makefile.am
@@ -92,7 +92,8 @@ noinst_HEADERS = \
 	strongly_connected_component.hh strongly_connected_component-fwd.hh \
 	suggest_restart.hh suggest_restart-fwd.hh \
 	unsuitable_candidates.hh unsuitable_candidates-fwd.hh \
-	use_existing.hh use_existing-fwd.hh use_existing-se.hh
+	use_existing.hh use_existing-fwd.hh use_existing-se.hh \
+	why_changed_choices.hh why_changed_choices-fwd.hh
 
 libpaludisresolver_a_SOURCES = \
 	accumulate_deps_and_provides.cc \
@@ -159,7 +160,8 @@ libpaludisresolver_a_SOURCES = \
 	strongly_connected_component.cc \
 	suggest_restart.cc \
 	unsuitable_candidates.cc \
-	use_existing.cc
+	use_existing.cc \
+	why_changed_choices.cc
 
 if ENABLE_VIRTUALS_REPOSITORY
 virtuals_tests = resolver_TEST_virtuals
diff --git a/paludis/resolver/decider.cc b/paludis/resolver/decider.cc
index d99b76773..eda0b992b 100644
--- a/paludis/resolver/decider.cc
+++ b/paludis/resolver/decider.cc
@@ -36,6 +36,7 @@
 #include <paludis/resolver/collect_installed.hh>
 #include <paludis/resolver/collect_purges.hh>
 #include <paludis/resolver/accumulate_deps_and_provides.hh>
+#include <paludis/resolver/why_changed_choices.hh>
 #include <paludis/util/exception.hh>
 #include <paludis/util/stringify.hh>
 #include <paludis/util/make_named_values.hh>
@@ -752,7 +753,8 @@ namespace
 
         bool visit(const ChangesToMakeDecision & decision) const
         {
-            return ok(decision.origin_id(), decision.if_changed_choices());
+            return ok(decision.origin_id(),
+                    decision.if_changed_choices() ? decision.if_changed_choices()->changed_choices() : make_null_shared_ptr());
         }
 
         bool visit(const ExistingNoChangeDecision & decision) const
@@ -902,7 +904,7 @@ namespace
     {
         const std::shared_ptr<const ChangedChoices> visit(const ChangesToMakeDecision & d) const
         {
-            return d.if_changed_choices();
+            return d.if_changed_choices() ? d.if_changed_choices()->changed_choices() : make_null_shared_ptr();
         }
 
         const std::shared_ptr<const ChangedChoices> visit(const ExistingNoChangeDecision &) const
@@ -1160,7 +1162,8 @@ namespace
         const std::pair<std::shared_ptr<const PackageID>, std::shared_ptr<const ChangedChoices> > visit(const ChangesToMakeDecision & decision) const
         {
             if (decision.taken())
-                return std::make_pair(decision.origin_id(), decision.if_changed_choices());
+                return std::make_pair(decision.origin_id(),
+                        decision.if_changed_choices() ? decision.if_changed_choices()->changed_choices() : make_null_shared_ptr());
             else
                 return std::make_pair(make_null_shared_ptr(), make_null_shared_ptr());
         }
@@ -1543,7 +1546,7 @@ Decider::_try_to_find_decision_for(
     const std::shared_ptr<const PackageID> existing_id(_find_existing_id_for(resolution));
 
     std::shared_ptr<const PackageID> installable_id;
-    std::shared_ptr<const ChangedChoices> changed_choices;
+    std::shared_ptr<const WhyChangedChoices> changed_choices;
     bool best;
     std::tie(installable_id, changed_choices, best) = _find_installable_id_for(resolution, try_option_changes_this_time, try_masked_this_time);
 
@@ -1865,7 +1868,10 @@ Decider::_find_id_for_from(
 
         if (ok)
         {
-            std::shared_ptr<ChangedChoices> changed_choices(std::make_shared<ChangedChoices>());
+            auto why_changed_choices(std::make_shared<WhyChangedChoices>(WhyChangedChoices(make_named_values<WhyChangedChoices>(
+                                n::changed_choices() = std::make_shared<ChangedChoices>(),
+                                n::reasons() = std::make_shared<Reasons>()
+                                ))));
             if (trying_changing_choices)
             {
                 for (Constraints::ConstIterator c(resolution->constraints()->begin()),
@@ -1895,12 +1901,17 @@ Decider::_find_id_for_from(
                     for (auto a((*c)->spec().if_package()->additional_requirements_ptr()->begin()),
                             a_end((*c)->spec().if_package()->additional_requirements_ptr()->end()) ;
                             a != a_end ; ++a)
-                        if ((*a)->accumulate_changes_to_make_met(_imp->env,
-                                    get_changed_choices_for(*c).get(), *i, *changed_choices).is_false())
+                    {
+                        auto b((*a)->accumulate_changes_to_make_met(_imp->env,
+                                    get_changed_choices_for(*c).get(), *i, *why_changed_choices->changed_choices()));
+                        if (b.is_false())
                         {
                             ok = false;
                             break;
                         }
+                        else if (b.is_true())
+                            why_changed_choices->reasons()->push_back((*c)->reason());
+                    }
                 }
             }
 
@@ -1915,14 +1926,16 @@ Decider::_find_id_for_from(
 
                 if ((*c)->spec().if_package())
                     ok = ok && match_package_with_maybe_changes(*_imp->env, *(*c)->spec().if_package(),
-                            get_changed_choices_for(*c).get(), **i, changed_choices.get(), { });
+                            get_changed_choices_for(*c).get(), **i, why_changed_choices->changed_choices().get(), { });
                 else
                     ok = ok && ! match_package_with_maybe_changes(*_imp->env, (*c)->spec().if_block()->blocking(),
-                            get_changed_choices_for(*c).get(), **i, changed_choices.get(), { });
+                            get_changed_choices_for(*c).get(), **i, why_changed_choices->changed_choices().get(), { });
             }
 
             if (ok)
-                return FoundID(*i, changed_choices->empty() ? make_null_shared_ptr() : changed_choices, (*i)->version() == best_version->version());
+                return FoundID(*i,
+                        why_changed_choices->changed_choices()->empty() ? make_null_shared_ptr() : why_changed_choices,
+                        (*i)->version() == best_version->version());
         }
     }
 
diff --git a/paludis/resolver/decider.hh b/paludis/resolver/decider.hh
index 93a7a4f91..4cab5754c 100644
--- a/paludis/resolver/decider.hh
+++ b/paludis/resolver/decider.hh
@@ -38,6 +38,7 @@
 #include <paludis/resolver/package_or_block_dep_spec-fwd.hh>
 #include <paludis/resolver/resolutions_by_resolvent-fwd.hh>
 #include <paludis/resolver/change_by_resolvent-fwd.hh>
+#include <paludis/resolver/why_changed_choices-fwd.hh>
 #include <paludis/util/attributes.hh>
 #include <paludis/util/pimp.hh>
 #include <paludis/util/tribool-fwd.hh>
@@ -57,7 +58,7 @@ namespace paludis
             private Pimp<Decider>
         {
             private:
-                typedef std::tuple<std::shared_ptr<const PackageID>, std::shared_ptr<const ChangedChoices>, bool> FoundID;
+                typedef std::tuple<std::shared_ptr<const PackageID>, std::shared_ptr<const WhyChangedChoices>, bool> FoundID;
 
                 const std::shared_ptr<Resolution> _create_resolution_for_resolvent(const Resolvent &) const;
                 const std::shared_ptr<Resolution> _resolution_for_resolvent(const Resolvent &, const Tribool);
diff --git a/paludis/resolver/decision.cc b/paludis/resolver/decision.cc
index 842de0079..8bc1987f3 100644
--- a/paludis/resolver/decision.cc
+++ b/paludis/resolver/decision.cc
@@ -22,6 +22,7 @@
 #include <paludis/resolver/unsuitable_candidates.hh>
 #include <paludis/resolver/resolvent.hh>
 #include <paludis/resolver/required_confirmations.hh>
+#include <paludis/resolver/why_changed_choices.hh>
 #include <paludis/util/make_named_values.hh>
 #include <paludis/util/make_shared_copy.hh>
 #include <paludis/util/stringify.hh>
@@ -122,7 +123,7 @@ ChangesToMakeDecision::deserialise(Deserialisation & d)
     std::shared_ptr<ChangesToMakeDecision> result(std::make_shared<ChangesToMakeDecision>(
                 v.member<Resolvent>("resolvent"),
                 v.member<std::shared_ptr<const PackageID> >("origin_id"),
-                v.member<std::shared_ptr<const ChangedChoices> >("if_changed_choices"),
+                v.member<std::shared_ptr<const WhyChangedChoices> >("if_changed_choices"),
                 v.member<bool>("best"),
                 destringify<ChangeType>(v.member<std::string>("change_type")),
                 v.member<bool>("taken"),
@@ -331,7 +332,7 @@ namespace paludis
     {
         const Resolvent resolvent;
         const std::shared_ptr<const PackageID> origin_id;
-        const std::shared_ptr<const ChangedChoices> changed_choices;
+        const std::shared_ptr<const WhyChangedChoices> changed_choices;
         const bool best;
         ChangeType change_type;
         const bool taken;
@@ -342,7 +343,7 @@ namespace paludis
         Imp(
                 const Resolvent & l,
                 const std::shared_ptr<const PackageID> & o,
-                const std::shared_ptr<const ChangedChoices> & h,
+                const std::shared_ptr<const WhyChangedChoices> & h,
                 const bool b,
                 const ChangeType c,
                 const bool t,
@@ -362,7 +363,7 @@ namespace paludis
 ChangesToMakeDecision::ChangesToMakeDecision(
         const Resolvent & r,
         const std::shared_ptr<const PackageID> & o,
-        const std::shared_ptr<const ChangedChoices> & h,
+        const std::shared_ptr<const WhyChangedChoices> & h,
         const bool b,
         const ChangeType c,
         const bool t,
@@ -408,7 +409,7 @@ ChangesToMakeDecision::origin_id() const
     return _imp->origin_id;
 }
 
-const std::shared_ptr<const ChangedChoices>
+const std::shared_ptr<const WhyChangedChoices>
 ChangesToMakeDecision::if_changed_choices() const
 {
     return _imp->changed_choices;
diff --git a/paludis/resolver/decision.hh b/paludis/resolver/decision.hh
index eab8fee04..81dbe9e77 100644
--- a/paludis/resolver/decision.hh
+++ b/paludis/resolver/decision.hh
@@ -26,6 +26,7 @@
 #include <paludis/resolver/change_type-fwd.hh>
 #include <paludis/resolver/resolvent-fwd.hh>
 #include <paludis/resolver/required_confirmations-fwd.hh>
+#include <paludis/resolver/why_changed_choices-fwd.hh>
 #include <paludis/util/pimp.hh>
 #include <paludis/util/simple_visitor.hh>
 #include <paludis/util/type_list.hh>
@@ -152,7 +153,7 @@ namespace paludis
                 ChangesToMakeDecision(
                         const Resolvent &,
                         const std::shared_ptr<const PackageID> &,
-                        const std::shared_ptr<const ChangedChoices> &,
+                        const std::shared_ptr<const WhyChangedChoices> &,
                         const bool best,
                         const ChangeType,
                         const bool taken,
@@ -170,7 +171,7 @@ namespace paludis
                 const std::shared_ptr<const PackageID> origin_id() const
                     PALUDIS_ATTRIBUTE((warn_unused_result));
 
-                const std::shared_ptr<const ChangedChoices> if_changed_choices() const
+                const std::shared_ptr<const WhyChangedChoices> if_changed_choices() const
                     PALUDIS_ATTRIBUTE((warn_unused_result));
 
                 const std::shared_ptr<const RepositoryName> if_via_new_binary_in() const
diff --git a/paludis/resolver/reason-fwd.hh b/paludis/resolver/reason-fwd.hh
index cbe8cd5cb..b6c6bdbe2 100644
--- a/paludis/resolver/reason-fwd.hh
+++ b/paludis/resolver/reason-fwd.hh
@@ -21,6 +21,8 @@
 #define PALUDIS_GUARD_PALUDIS_RESOLVER_REASON_FWD_HH 1
 
 #include <paludis/util/attributes.hh>
+#include <paludis/util/sequence-fwd.hh>
+#include <memory>
 
 namespace paludis
 {
@@ -35,6 +37,8 @@ namespace paludis
         struct WasUsedByReason;
         struct LikeOtherDestinationTypeReason;
         struct ViaBinaryReason;
+
+        typedef Sequence<std::shared_ptr<const Reason> > Reasons;
     }
 }
 
diff --git a/paludis/resolver/reason.cc b/paludis/resolver/reason.cc
index 94057d78b..a0ec6cd60 100644
--- a/paludis/resolver/reason.cc
+++ b/paludis/resolver/reason.cc
@@ -23,6 +23,8 @@
 #include <paludis/resolver/change_by_resolvent.hh>
 #include <paludis/util/stringify.hh>
 #include <paludis/util/pimp-impl.hh>
+#include <paludis/util/sequence-impl.hh>
+#include <paludis/util/wrapped_forward_iterator-impl.hh>
 #include <paludis/serialise-impl.hh>
 #include <paludis/changed_choices.hh>
 
@@ -478,3 +480,6 @@ template class Pimp<WasUsedByReason>;
 template class Pimp<LikeOtherDestinationTypeReason>;
 template class Pimp<ViaBinaryReason>;
 
+template class Sequence<std::shared_ptr<const Reason> >;
+template class WrappedForwardIterator<Reasons::ConstIteratorTag, const std::shared_ptr<const Reason> >;
+
diff --git a/paludis/resolver/why_changed_choices-fwd.hh b/paludis/resolver/why_changed_choices-fwd.hh
new file mode 100644
index 000000000..fdbedc4aa
--- /dev/null
+++ b/paludis/resolver/why_changed_choices-fwd.hh
@@ -0,0 +1,31 @@
+/* vim: set sw=4 sts=4 et foldmethod=syntax : */
+
+/*
+ * Copyright (c) 2010 Ciaran McCreesh
+ *
+ * This file is part of the Paludis package manager. Paludis is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU General
+ * Public License version 2, as published by the Free Software Foundation.
+ *
+ * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef PALUDIS_GUARD_PALUDIS_RESOLVER_WHY_CHANGED_CHOICES_FWD_HH
+#define PALUDIS_GUARD_PALUDIS_RESOLVER_WHY_CHANGED_CHOICES_FWD_HH 1
+
+namespace paludis
+{
+    namespace resolver
+    {
+        struct WhyChangedChoices;
+    }
+}
+
+#endif
diff --git a/paludis/resolver/why_changed_choices.cc b/paludis/resolver/why_changed_choices.cc
new file mode 100644
index 000000000..13a3b060a
--- /dev/null
+++ b/paludis/resolver/why_changed_choices.cc
@@ -0,0 +1,59 @@
+/* vim: set sw=4 sts=4 et foldmethod=syntax : */
+
+/*
+ * Copyright (c) 2010 Ciaran McCreesh
+ *
+ * This file is part of the Paludis package manager. Paludis is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU General
+ * Public License version 2, as published by the Free Software Foundation.
+ *
+ * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <paludis/resolver/why_changed_choices.hh>
+#include <paludis/resolver/reason.hh>
+#include <paludis/util/sequence.hh>
+#include <paludis/util/wrapped_forward_iterator.hh>
+#include <paludis/util/make_named_values.hh>
+#include <paludis/serialise-impl.hh>
+#include <paludis/changed_choices.hh>
+
+using namespace paludis;
+using namespace paludis::resolver;
+
+void
+WhyChangedChoices::serialise(Serialiser & s) const
+{
+    auto ss(s.object("WhyChangedChoices"));
+
+    ss.member(SerialiserFlags<serialise::might_be_null>(), "changed_choices", changed_choices());
+
+    int n(0);
+    for (auto o(reasons()->begin()), o_end(reasons()->end()) ;
+            o != o_end ; ++o)
+        ss.member(SerialiserFlags<>(), stringify(++n), **o);
+    ss.member(SerialiserFlags<>(), "reasons_count", stringify(n));
+}
+
+const std::shared_ptr<WhyChangedChoices>
+WhyChangedChoices::deserialise(Deserialisation & d)
+{
+    Deserialisator v(d, "WhyChangedChoices");
+    auto result(std::make_shared<WhyChangedChoices>(make_named_values<WhyChangedChoices>(
+                    n::changed_choices() = v.member<std::shared_ptr<ChangedChoices> >("changed_choices"),
+                    n::reasons() = std::make_shared<Reasons>()
+                    )));
+
+    for (int n(1), n_end(v.member<int>("reasons_count") + 1) ; n != n_end ; ++n)
+        result->reasons()->push_back(v.member<std::shared_ptr<Reason> >(stringify(n)));
+
+    return result;
+}
+
diff --git a/paludis/resolver/why_changed_choices.hh b/paludis/resolver/why_changed_choices.hh
new file mode 100644
index 000000000..e1ceebdd4
--- /dev/null
+++ b/paludis/resolver/why_changed_choices.hh
@@ -0,0 +1,52 @@
+/* vim: set sw=4 sts=4 et foldmethod=syntax : */
+
+/*
+ * Copyright (c) 2010 Ciaran McCreesh
+ *
+ * This file is part of the Paludis package manager. Paludis is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU General
+ * Public License version 2, as published by the Free Software Foundation.
+ *
+ * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef PALUDIS_GUARD_PALUDIS_RESOLVER_WHY_CHANGED_CHOICES_HH
+#define PALUDIS_GUARD_PALUDIS_RESOLVER_WHY_CHANGED_CHOICES_HH 1
+
+#include <paludis/resolver/why_changed_choices-fwd.hh>
+#include <paludis/resolver/reason-fwd.hh>
+#include <paludis/util/named_value.hh>
+#include <paludis/changed_choices-fwd.hh>
+#include <paludis/serialise-fwd.hh>
+
+namespace paludis
+{
+    namespace n
+    {
+        typedef Name<struct changed_choices_name> changed_choices;
+        typedef Name<struct reasons_name> reasons;
+    }
+
+    namespace resolver
+    {
+        struct WhyChangedChoices
+        {
+            NamedValue<n::changed_choices, std::shared_ptr<ChangedChoices> > changed_choices;
+            NamedValue<n::reasons, std::shared_ptr<Reasons> > reasons;
+
+            void serialise(Serialiser &) const;
+
+            static const std::shared_ptr<WhyChangedChoices> deserialise(
+                    Deserialisation & d) PALUDIS_ATTRIBUTE((warn_unused_result));
+        };
+    }
+}
+
+#endif
diff --git a/src/clients/cave/cmd_display_resolution.cc b/src/clients/cave/cmd_display_resolution.cc
index 612c58590..e6e69912e 100755
--- a/src/clients/cave/cmd_display_resolution.cc
+++ b/src/clients/cave/cmd_display_resolution.cc
@@ -57,6 +57,7 @@
 #include <paludis/resolver/orderer_notes.hh>
 #include <paludis/resolver/change_by_resolvent.hh>
 #include <paludis/resolver/match_qpns.hh>
+#include <paludis/resolver/why_changed_choices.hh>
 #include <paludis/package_id.hh>
 #include <paludis/version_spec.hh>
 #include <paludis/metadata_key.hh>
@@ -523,7 +524,7 @@ namespace
             const std::shared_ptr<Environment> &,
             const DisplayResolutionCommandLine & cmdline,
             const std::shared_ptr<const PackageID> & id,
-            const std::shared_ptr<const ChangedChoices> & changed_choices,
+            const std::shared_ptr<const WhyChangedChoices> & changed_choices,
             const std::shared_ptr<const PackageID> & old_id,
             ChoicesToExplain & choices_to_explain
             )
@@ -554,7 +555,7 @@ namespace
 
                 Tribool changed_state(indeterminate);
                 if (changed_choices)
-                    changed_state = changed_choices->overridden_value((*i)->name_with_prefix());
+                    changed_state = changed_choices->changed_choices()->overridden_value((*i)->name_with_prefix());
 
                 auto & s_prefix(changed_state.is_indeterminate() ? unchanged_s_prefix : changed_s_prefix);
                 auto & shown_prefix(changed_state.is_indeterminate() ? shown_prefix_unchanged : shown_prefix_changed);