[m-dev.] diff: fix tabling nonlocals bug

[Fergus Henderson]

Estimated hours taken: 2

compiler/table_gen.m:
	Fix a bug: it was computing the non-locals set incorrectly,
	in cases where the goal for the tabled predicate did not
	use all of the head variables for that predicate.

tests/tabling/Mmakefile:
tests/tabling/unused_args.m:
tests/tabling/unused_args.exp:
	Add a regression test for this bug.

Workspace: /home/mercury0/fjh/mercury
Index: compiler/table_gen.m
===================================================================
RCS file: /home/mercury1/repository/mercury/compiler/table_gen.m,v
retrieving revision 1.17
diff -u -d -r1.17 table_gen.m
--- compiler/table_gen.m	2000/03/13 02:23:08	1.17
+++ compiler/table_gen.m	2000/04/03 10:56:34
@@ -301,8 +301,12 @@
 table_gen__create_new_det_goal(EvalMethod, OrigGoal, PredId, ProcId,
 		HeadVars, HeadVarModes, VarTypes0, VarTypes,
 		VarSet0, VarSet, TableInfo0, TableInfo, Goal) :-
+	% even if the original goal doesn't use all of the headvars,
+	% the code generated by the tabling transformation does,
+	% so we need to compute the nonlocals from the headvars rather
+	% than getting it from the nonlocals field in the original goal
+	set__list_to_set(HeadVars, OrigNonLocals),
 	OrigGoal = _ - OrigGoalInfo,
-	goal_info_get_nonlocals(OrigGoalInfo, OrigNonLocals),
 	goal_info_get_instmap_delta(OrigGoalInfo, OrigInstMapDelta),
 	goal_info_get_context(OrigGoalInfo, Context),
 
@@ -392,8 +396,12 @@
 table_gen__create_new_semi_goal(EvalMethod, OrigGoal, PredId, ProcId,
 		HeadVars, HeadVarModes, VarTypes0, VarTypes,
 		VarSet0, VarSet, TableInfo0, TableInfo, Goal) :-
+	% even if the original goal doesn't use all of the headvars,
+	% the code generated by the tabling transformation does,
+	% so we need to compute the nonlocals from the headvars rather
+	% than getting it from the nonlocals field in the original goal
+	set__list_to_set(HeadVars, OrigNonLocals),
 	OrigGoal = _ - OrigGoalInfo,
-	goal_info_get_nonlocals(OrigGoalInfo, OrigNonLocals),
 	goal_info_get_instmap_delta(OrigGoalInfo, OrigInstMapDelta),
 	goal_info_get_context(OrigGoalInfo, Context),
 
@@ -538,8 +546,12 @@
 table_gen__create_new_non_goal(EvalMethod, OrigGoal, PredId, ProcId,
 		HeadVars, HeadVarModes, VarTypes0, VarTypes,
 		VarSet0, VarSet, TableInfo0, TableInfo, Goal) :-
+	% even if the original goal doesn't use all of the headvars,
+	% the code generated by the tabling transformation does,
+	% so we need to compute the nonlocals from the headvars rather
+	% than getting it from the nonlocals field in the original goal
+	set__list_to_set(HeadVars, OrigNonLocals),
 	OrigGoal = _ - OrigGoalInfo,
-	goal_info_get_nonlocals(OrigGoalInfo, OrigNonLocals),
 	goal_info_get_instmap_delta(OrigGoalInfo, OrigInstMapDelta),
 	goal_info_get_context(OrigGoalInfo, Context),
 
Index: tests/tabling/Mmakefile
===================================================================
RCS file: /home/mercury1/repository/tests/tabling/Mmakefile,v
retrieving revision 1.10
diff -u -d -r1.10 Mmakefile
--- tests/tabling/Mmakefile	2000/01/03 08:53:10	1.10
+++ tests/tabling/Mmakefile	2000/04/03 11:08:46
@@ -15,7 +15,8 @@
 	fib_float \
 	fib_list \
 	fib_string \
-	loopcheck
+	loopcheck \
+	unused_args
 
 NONDET_PROGS = \
 	coup \
cvs diff: tests/tabling/unused_args.exp is a new entry, no comparison available
cvs diff: tests/tabling/unused_args.m is a new entry, no comparison available
==================================================
new file tests/tabling/unused_args.exp
==================================================
foo
bar
foo_fail failed, as expected
foo
bar
foo_fail failed, as expected
foo
bar
foo_fail failed, as expected
==================================================
new file tests/tabling/unused_args.m
==================================================
% Regression test.

% Versions rotd-2000-04-03 and earlier
% got a software error when compiling this test.

:- module unused_args.
:- interface.
:- import_module io.

:- pred main(io__state::di, io__state::uo) is det.

:- implementation.
:- import_module std_util.

main --> 
	test, test, test.

:- pred test(io__state::di, io__state::uo) is det.
:- pragma no_inline(test/2).

test -->
	{ foo_unused_args(42, Z) },
	print(Z), nl,
	( { foo_unused_args_semi(42, Y) } ->
		print(Y), nl
	;
		io__write_string("foo_unused_args failed\n")
	),
	( { foo_fail(X) } ->
		print(X), nl
	;
		io__write_string("foo_fail failed, as expected\n")
	).

:- pred foo_unused_args(int::in, string::out) is det.
:- pragma memo(foo_unused_args/2).
foo_unused_args(_, "foo").

:- pred foo_unused_args_semi(int::in, string::out) is semidet.
:- pragma memo(foo_unused_args_semi/2).
foo_unused_args_semi(_, "bar") :- semidet_succeed.

:- pred foo_fail(string::out) is semidet.
:- pragma memo(foo_fail/1).
foo_fail(_) :- fail.

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>  |  of excellence is a lethal habit"
PGP: finger fjh at 128.250.37.3        |     -- the last words of T. S. Garp.
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