Constraint::force_unable

7 files changed, 33 insertions, 1 deletions

diff --git a/paludis/resolver/constraint.cc b/paludis/resolver/constraint.cc
index c9a35e9de..f23e187e8 100644
--- a/paludis/resolver/constraint.cc
+++ b/paludis/resolver/constraint.cc
@@ -41,13 +41,15 @@ namespace paludis
         UseExisting strictest_use_existing;
         bool nothing_is_fine_too;
         bool all_untaken;
+        bool any_force_unable;
 
         Sequence<std::shared_ptr<const Constraint> > constraints;
 
         Imp() :
             strictest_use_existing(static_cast<UseExisting>(last_ue - 1)),
             nothing_is_fine_too(true),
-            all_untaken(true)
+            all_untaken(true),
+            any_force_unable(false)
         {
         }
     };
@@ -75,6 +77,12 @@ Constraints::all_untaken() const
 }
 
 bool
+Constraints::any_force_unable() const
+{
+    return _imp->any_force_unable;
+}
+
+bool
 Constraints::nothing_is_fine_too() const
 {
     return _imp->nothing_is_fine_too;
@@ -105,6 +113,7 @@ Constraints::add(const std::shared_ptr<const Constraint> & c)
     _imp->strictest_use_existing = std::min(_imp->strictest_use_existing, c->use_existing());
     _imp->nothing_is_fine_too = _imp->nothing_is_fine_too && c->nothing_is_fine_too();
     _imp->all_untaken = _imp->all_untaken && c->untaken();
+    _imp->any_force_unable = _imp->any_force_unable || c->force_unable();
 }
 
 bool
@@ -137,6 +146,7 @@ Constraint::serialise(Serialiser & s) const
 {
     s.object("Constraint")
         .member(SerialiserFlags<>(), "destination_type", stringify(destination_type()))
+        .member(SerialiserFlags<>(), "force_unable", stringify(force_unable()))
         .member(SerialiserFlags<>(), "nothing_is_fine_too", nothing_is_fine_too())
         .member(SerialiserFlags<serialise::might_be_null>(), "reason", reason())
         .member(SerialiserFlags<>(), "spec", spec())
@@ -203,6 +213,7 @@ Constraint::deserialise(Deserialisation & d)
 
     return std::make_shared<Constraint>(make_named_values<Constraint>(
                     n::destination_type() = destringify<DestinationType>(v.member<std::string>("destination_type")),
+                    n::force_unable() = v.member<bool>("force_unable"),
                     n::nothing_is_fine_too() = v.member<bool>("nothing_is_fine_too"),
                     n::reason() = reason,
                     n::spec() = PackageOrBlockDepSpec::deserialise(*v.find_remove_member("spec"),
diff --git a/paludis/resolver/constraint.hh b/paludis/resolver/constraint.hh
index e1d4fa873..e7a97e472 100644
--- a/paludis/resolver/constraint.hh
+++ b/paludis/resolver/constraint.hh
@@ -36,6 +36,7 @@ namespace paludis
     namespace n
     {
         typedef Name<struct destination_type_name> destination_type;
+        typedef Name<struct force_unable_name> force_unable;
         typedef Name<struct nothing_is_fine_too_name> nothing_is_fine_too;
         typedef Name<struct reason_name> reason;
         typedef Name<struct spec_name> spec;
@@ -48,6 +49,7 @@ namespace paludis
         struct Constraint
         {
             NamedValue<n::destination_type, DestinationType> destination_type;
+            NamedValue<n::force_unable, bool> force_unable;
             NamedValue<n::nothing_is_fine_too, bool> nothing_is_fine_too;
             NamedValue<n::reason, std::shared_ptr<const Reason> > reason;
             NamedValue<n::spec, PackageOrBlockDepSpec> spec;
@@ -69,6 +71,7 @@ namespace paludis
 
                 bool nothing_is_fine_too() const PALUDIS_ATTRIBUTE((warn_unused_result));
                 bool all_untaken() const PALUDIS_ATTRIBUTE((warn_unused_result));
+                bool any_force_unable() const PALUDIS_ATTRIBUTE((warn_unused_result));
                 UseExisting strictest_use_existing() const PALUDIS_ATTRIBUTE((warn_unused_result));
 
                 void add(const std::shared_ptr<const Constraint> &);
diff --git a/paludis/resolver/decider.cc b/paludis/resolver/decider.cc
index cc847b2c4..cb4e15c46 100644
--- a/paludis/resolver/decider.cc
+++ b/paludis/resolver/decider.cc
@@ -610,6 +610,7 @@ Decider::_make_constraints_from_target(
         const std::shared_ptr<ConstraintSequence> result(std::make_shared<ConstraintSequence>());
         result->push_back(std::make_shared<Constraint>(make_named_values<Constraint>(
                             n::destination_type() = resolution->resolvent().destination_type(),
+                            n::force_unable() = false,
                             n::nothing_is_fine_too() = existing.second,
                             n::reason() = reason,
                             n::spec() = spec,
@@ -638,6 +639,7 @@ Decider::_make_constraints_from_dependency(
         const std::shared_ptr<ConstraintSequence> result(std::make_shared<ConstraintSequence>());
         result->push_back(std::make_shared<Constraint>(make_named_values<Constraint>(
                             n::destination_type() = resolution->resolvent().destination_type(),
+                            n::force_unable() = false,
                             n::nothing_is_fine_too() = existing.second,
                             n::reason() = reason,
                             n::spec() = *dep.spec().if_package(),
@@ -665,6 +667,7 @@ Decider::_make_constraints_from_blocker(
         if (destination_types[*t])
             result->push_back(std::make_shared<Constraint>(make_named_values<Constraint>(
                                 n::destination_type() = *t,
+                                n::force_unable() = false,
                                 n::nothing_is_fine_too() = true,
                                 n::reason() = reason,
                                 n::spec() = spec,
@@ -707,6 +710,9 @@ namespace
         bool ok(const std::shared_ptr<const PackageID> & chosen_id,
                 const std::shared_ptr<const ChangedChoices> & changed_choices) const
         {
+            if (constraint.force_unable())
+                return false;
+
             if (constraint.spec().if_package())
             {
                 if (! match_package_with_maybe_changes(*env, *constraint.spec().if_package(),
@@ -745,6 +751,9 @@ namespace
 
         bool visit(const RemoveDecision &) const
         {
+            if (constraint.force_unable())
+                return false;
+
             return constraint.nothing_is_fine_too();
         }
 
@@ -1511,6 +1520,9 @@ Decider::_try_to_find_decision_for(
         const bool try_masked_this_time,
         const bool try_removes_if_allowed) const
 {
+    if (resolution->constraints()->any_force_unable())
+        return make_null_shared_ptr();
+
     const std::shared_ptr<const PackageID> existing_id(_find_existing_id_for(resolution));
 
     std::shared_ptr<const PackageID> installable_id;
@@ -2358,6 +2370,7 @@ namespace
             std::shared_ptr<ConstraintSequence> result(std::make_shared<ConstraintSequence>());
             result->push_back(make_shared_copy(make_named_values<Constraint>(
                             n::destination_type() = destination_type,
+                            n::force_unable() = false,
                             n::nothing_is_fine_too() = true,
                             n::reason() = std::make_shared<LikeOtherDestinationTypeReason>(
                                     resolvent,
diff --git a/paludis/resolver/get_constraints_for_dependent_helper.cc b/paludis/resolver/get_constraints_for_dependent_helper.cc
index 642699aea..d27f9a64e 100644
--- a/paludis/resolver/get_constraints_for_dependent_helper.cc
+++ b/paludis/resolver/get_constraints_for_dependent_helper.cc
@@ -93,6 +93,7 @@ GetConstraintsForDependentHelper::operator() (
 
         result->push_back(std::make_shared<Constraint>(make_named_values<Constraint>(
                         n::destination_type() = dt_install_to_slash,
+                        n::force_unable() = false,
                         n::nothing_is_fine_too() = true,
                         n::reason() = reason,
                         n::spec() = BlockDepSpec("!" + stringify(*spec), *spec, bk_weak),
diff --git a/paludis/resolver/get_constraints_for_purge_helper.cc b/paludis/resolver/get_constraints_for_purge_helper.cc
index 625ae8887..631a1e423 100644
--- a/paludis/resolver/get_constraints_for_purge_helper.cc
+++ b/paludis/resolver/get_constraints_for_purge_helper.cc
@@ -84,6 +84,7 @@ GetConstraintsForPurgeHelper::operator() (
 
     result->push_back(std::make_shared<Constraint>(make_named_values<Constraint>(
                     n::destination_type() = dt_install_to_slash,
+                    n::force_unable() = false,
                     n::nothing_is_fine_too() = true,
                     n::reason() = reason,
                     n::spec() = BlockDepSpec("!" + stringify(spec), spec, bk_weak),
diff --git a/paludis/resolver/get_constraints_for_via_binary_helper.cc b/paludis/resolver/get_constraints_for_via_binary_helper.cc
index 3f4cd7c92..ee7ea91ff 100644
--- a/paludis/resolver/get_constraints_for_via_binary_helper.cc
+++ b/paludis/resolver/get_constraints_for_via_binary_helper.cc
@@ -70,6 +70,7 @@ GetConstraintsForViaBinaryHelper::operator() (
 
     result->push_back(std::make_shared<Constraint>(make_named_values<Constraint>(
                     n::destination_type() = resolution->resolvent().destination_type(),
+                    n::force_unable() = false,
                     n::nothing_is_fine_too() = false,
                     n::reason() = reason,
                     n::spec() = spec,
diff --git a/paludis/resolver/get_initial_constraints_for_helper.cc b/paludis/resolver/get_initial_constraints_for_helper.cc
index 33009769f..a82a3eedb 100644
--- a/paludis/resolver/get_initial_constraints_for_helper.cc
+++ b/paludis/resolver/get_initial_constraints_for_helper.cc
@@ -100,6 +100,7 @@ GetInitialConstraintsForHelper::add_preset_spec(const PackageDepSpec & spec)
 
             const std::shared_ptr<Constraint> constraint(std::make_shared<Constraint>(make_named_values<Constraint>(
                             n::destination_type() = r.destination_type(),
+                            n::force_unable() = false,
                             n::nothing_is_fine_too() = true,
                             n::reason() = reason,
                             n::spec() = spec,
@@ -252,6 +253,7 @@ GetInitialConstraintsForHelper::_make_initial_constraints_for(
     {
         result->add(std::make_shared<Constraint>(make_named_values<Constraint>(
                         n::destination_type() = resolvent.destination_type(),
+                        n::force_unable() = false,
                         n::nothing_is_fine_too() = true,
                         n::reason() = std::make_shared<PresetReason>("is scm", make_null_shared_ptr()),
                         n::spec() = make_package_dep_spec({ }).package(resolvent.package()),