expand module names in transitive goals (#2255)

Author: mthom

src/loader.pl

@@ -299,7 +299,7 @@
           (  atom(Module) ->
              prolog_load_context(module, Target),
              module_expanded_head_variables(Head2, HeadVars),
-             catch(expand_goal(Body0, Target, Body1, HeadVars),
+             catch(expand_goal(Body0, Target, Body1, HeadVars, []),
                    error(type_error(callable, Pred), _),
                    (  loader:print_goal_expansion_warning(Pred),
                       builtins:(Body1 = Body0)
@@ -309,7 +309,7 @@
           )
        ;  module_expanded_head_variables(Head1, HeadVars),
           prolog_load_context(module, Target),
-          catch(expand_goal(Body0, Target, Body1, HeadVars),
+          catch(expand_goal(Body0, Target, Body1, HeadVars, []),
                 error(type_error(callable, Pred), _),
                 (  loader:print_goal_expansion_warning(Pred),
                    builtins:(Body1 = Body0)
@@ -729,9 +729,9 @@
     ).
 
 
-:- non_counted_backtracking expand_subgoal/5.
+:- non_counted_backtracking expand_subgoal/6.
 
-expand_subgoal(UnexpandedGoals, MS, M, ExpandedGoals, HeadVars) :-
+expand_subgoal(UnexpandedGoals, MS, M, ExpandedGoals, HeadVars, TGs) :-
     strip_subst_module(UnexpandedGoals, M, Module, UnexpandedGoals0),
     nonvar(UnexpandedGoals0),
     complete_partial_goal(MS, UnexpandedGoals0, _, SuppArgs, UnexpandedGoals1),
@@ -743,7 +743,7 @@
     ),
     strip_subst_module(UnexpandedGoals3, Module, Module1, UnexpandedGoals4),
     (  inner_meta_specs(0, UnexpandedGoals4, _, MetaSpecs) ->
-       expand_module_names(UnexpandedGoals4, MetaSpecs, Module1, ExpandedGoals0, HeadVars)
+       expand_module_names(UnexpandedGoals4, MetaSpecs, Module1, ExpandedGoals0, HeadVars, TGs)
     ;  ExpandedGoals0 = UnexpandedGoals4
     ),
     '$compile_inline_or_expanded_goal'(ExpandedGoals0, SuppArgs, ExpandedGoals1, Module1, UnexpandedGoals0),
@@ -772,10 +772,10 @@
 
 :- non_counted_backtracking eq_member/2.
 
-eq_member(V, [L-_|Ls]) :-
+eq_member(V-M, [L-M|Ls]) :-
     V == L.
-eq_member(V, [_|Ls]) :-
-    eq_member(V, Ls).
+eq_member(V-M, [_|Ls]) :-
+    eq_member(V-M, Ls).
 
 :- non_counted_backtracking qualified_spec/1.
 
@@ -785,11 +785,19 @@
 
 :- non_counted_backtracking expand_meta_predicate_subgoals/5.
 
-expand_meta_predicate_subgoals([SG | SGs], [MS | MSs], M, [ESG | ESGs], HeadVars) :-
+expand_meta_predicate_subgoals([SG | SGs], [MS | MSs], M, [ESG | ESGs], HeadVars, TGs) :-
     (  var(SG) ->
        (  qualified_spec(MS) ->
-          (  eq_member(SG, HeadVars) ->
+          (  eq_member(SG-_, HeadVars) ->
              ESG = SG
+          ;  eq_member(SG-TG, TGs),
+             % transitive goals come about from previous equalities:
+             % if SG was bound by (=)/2 to a potential goal TG earlier
+             % in the goal sequence, expand TG and substitute SG with it
+             % in this subgoal context. the binding to SG must not be
+             % changed.
+             expand_subgoal(TG, MS, M, ESG, HeadVars, TGs) ->
+             true
           ;  expand_module_name(SG, MS, M, ESG)
           )
        ;  ESG = SG
@@ -798,53 +806,53 @@
        expand_module_name(SG, MS, M, ESG)
     ;  '$is_expanded_or_inlined'(SG) ->
        ESG = SG
-    ;  expand_subgoal(SG, MS, M, ESG, HeadVars) ->
+    ;  expand_subgoal(SG, MS, M, ESG, HeadVars, TGs) ->
        true
     ;  integer(MS),
        MS >= 0 ->
        expand_module_name(SG, MS, M, ESG)
     ;  SG = ESG
     ),
-    expand_meta_predicate_subgoals(SGs, MSs, M, ESGs, HeadVars).
+    expand_meta_predicate_subgoals(SGs, MSs, M, ESGs, HeadVars, TGs).
 
-expand_meta_predicate_subgoals([], _, _, [], _).
+expand_meta_predicate_subgoals([], _, _, [], _, _).
 
-:- non_counted_backtracking expand_module_names/5.
+:- non_counted_backtracking expand_module_names/6.
 
-expand_module_names(Goals, MetaSpecs, Module, ExpandedGoals, HeadVars) :-
+expand_module_names(Goals, MetaSpecs, Module, ExpandedGoals, HeadVars, TGs) :-
     Goals =.. [GoalFunctor | SubGoals],
     (  GoalFunctor == (:),
        SubGoals = [M, SubGoal] ->
-       expand_module_names(SubGoal, MetaSpecs, M, ExpandedSubGoal, HeadVars),
+       expand_module_names(SubGoal, MetaSpecs, M, ExpandedSubGoal, HeadVars, TGs),
        expand_module_name(ExpandedSubGoal, 0, M, ExpandedGoals)
-    ;  expand_meta_predicate_subgoals(SubGoals, MetaSpecs, Module, ExpandedGoalList, HeadVars),
+    ;  expand_meta_predicate_subgoals(SubGoals, MetaSpecs, Module, ExpandedGoalList, HeadVars, TGs),
        ExpandedGoals =.. [GoalFunctor | ExpandedGoalList]
     ).
 
 
 :- non_counted_backtracking expand_goal/3.
 
 expand_goal(UnexpandedGoals, Module, ExpandedGoals) :-
-    catch(loader:expand_goal(UnexpandedGoals, Module, ExpandedGoals, []),
+    catch(loader:expand_goal(UnexpandedGoals, Module, ExpandedGoals, [], []),
           error(type_error(callable, _), _),
           UnexpandedGoals = ExpandedGoals),
     !.
 
-:- non_counted_backtracking expand_goal/4.
+:- non_counted_backtracking expand_goal/5.
 
-expand_goal(UnexpandedGoals, Module, ExpandedGoals, HeadVars) :-
+expand_goal(UnexpandedGoals, Module, ExpandedGoals, HeadVars, TGs) :-
     (  var(UnexpandedGoals) ->
-       expand_module_names(call(UnexpandedGoals), [0], Module, ExpandedGoals, HeadVars)
+       expand_module_names(call(UnexpandedGoals), [0], Module, ExpandedGoals, HeadVars, TGs)
     ;  goal_expansion(UnexpandedGoals, Module, UnexpandedGoals1),
        (  Module \== user ->
           goal_expansion(UnexpandedGoals1, user, Goals)
        ;  Goals = UnexpandedGoals1
        ),
-       (  expand_goal_cases(Goals, Module, ExpandedGoals, HeadVars) ->
+       (  expand_goal_cases(Goals, Module, ExpandedGoals, HeadVars, TGs) ->
           true
        ;  predicate_property(Module:Goals, meta_predicate(MetaSpecs0)),
           MetaSpecs0 =.. [_ | MetaSpecs] ->
-          expand_module_names(Goals, MetaSpecs, Module, ExpandedGoals, HeadVars)
+          expand_module_names(Goals, MetaSpecs, Module, ExpandedGoals, HeadVars, TGs)
        ;  thread_goals(Goals, ExpandedGoals, (','))
        ;  Goals = ExpandedGoals
        )
@@ -877,28 +885,40 @@
        )
     ).
 
-:- non_counted_backtracking expand_goal_cases/4.
+:- non_counted_backtracking transitive_goal/3.
+
+transitive_goal(G, TGs0, TGs1) :-
+    (  G = (G1 = PotentialGoal),
+       callable(PotentialGoal),
+       subsumes_term(G1, PotentialGoal) ->
+       TGs1 = [G1-PotentialGoal|TGs0]
+    ;  TGs1 = TGs0
+    ).
+
+:- non_counted_backtracking expand_goal_cases/5.
 
-expand_goal_cases((Goal0, Goals0), Module, ExpandedGoals, HeadVars) :-
-    (  expand_goal(Goal0, Module, Goal1, HeadVars) ->
-       expand_goal(Goals0, Module, Goals1, HeadVars),
+expand_goal_cases((Goal0, Goals0), Module, ExpandedGoals, HeadVars, TGs) :-
+    (  expand_goal(Goal0, Module, Goal1, HeadVars, TGs) ->
+       transitive_goal(Goal0, TGs, TGs1),
+       expand_goal(Goals0, Module, Goals1, HeadVars, TGs1),
        thread_goals(Goal1, ExpandedGoals, Goals1, (','))
-    ;  expand_goal(Goals0, Module, Goals1, HeadVars),
+    ;  expand_goal(Goals0, Module, Goals1, HeadVars, TGs),
        ExpandedGoals = (Goal0, Goals1)
     ).
-expand_goal_cases((Goals0 -> Goals1), Module, ExpandedGoals, HeadVars) :-
-    expand_goal(Goals0, Module, ExpandedGoals0, HeadVars),
-    expand_goal(Goals1, Module, ExpandedGoals1, HeadVars),
+expand_goal_cases((Goals0 -> Goals1), Module, ExpandedGoals, HeadVars, TGs) :-
+    expand_goal(Goals0, Module, ExpandedGoals0, HeadVars, TGs),
+    transitive_goal(ExpandedGoals0, TGs, TGs1),
+    expand_goal(Goals1, Module, ExpandedGoals1, HeadVars, TGs1),
     ExpandedGoals = (ExpandedGoals0 -> ExpandedGoals1).
-expand_goal_cases((Goals0 ; Goals1), Module, ExpandedGoals, HeadVars) :-
-    expand_goal(Goals0, Module, ExpandedGoals0, HeadVars),
-    expand_goal(Goals1, Module, ExpandedGoals1, HeadVars),
+expand_goal_cases((Goals0 ; Goals1), Module, ExpandedGoals, HeadVars, TGs) :-
+    expand_goal(Goals0, Module, ExpandedGoals0, HeadVars, TGs),
+    expand_goal(Goals1, Module, ExpandedGoals1, HeadVars, TGs),
     ExpandedGoals = (ExpandedGoals0 ; ExpandedGoals1).
-expand_goal_cases((\+ Goals0), Module, ExpandedGoals, HeadVars) :-
-    expand_goal(Goals0, Module, Goals1, HeadVars),
+expand_goal_cases((\+ Goals0), Module, ExpandedGoals, HeadVars, TGs) :-
+    expand_goal(Goals0, Module, Goals1, HeadVars, TGs),
     ExpandedGoals = (\+ Goals1).
-expand_goal_cases((Module:Goals0), _, ExpandedGoals, HeadVars) :-
-    expand_goal(Goals0, Module, Goals1, HeadVars),
+expand_goal_cases((Module:Goals0), _, ExpandedGoals, HeadVars, TGs) :-
+    expand_goal(Goals0, Module, Goals1, HeadVars, TGs),
     ExpandedGoals = (Module:Goals1).
 
 :- non_counted_backtracking thread_goals/3.