[m-rev.] for review: unused arg determinism bug fix

[Peter Ross]

Hi,

For Simon to review.

===================================================================


Estimated hours taken: 4
Branches: main

Fix a bug where unused argument procedures were being called from the
wrong code_model in their parent procedure.  This bug only shows up on
the MLDS backends.

compiler/unused_args.m:
    Use the declared determinism for determining the determinism of a
    call to a unused argument procedure, not the actual determinism.

tests/valid/Mmakefile:
tests/valid/unused_arg_determinism.exp:
tests/valid/unused_arg_determinism.m:
    Test case.

Index: compiler/unused_args.m
===================================================================
RCS file: /home/staff/zs/imp/mercury/compiler/unused_args.m,v
retrieving revision 1.73
diff -u -r1.73 unused_args.m
--- compiler/unused_args.m	7 Apr 2001 14:05:03 -0000	1.73
+++ compiler/unused_args.m	12 Feb 2002 13:35:09 -0000
@@ -982,6 +982,18 @@
 	proc_info_headvars(OldProc0, HeadVars),
 	proc_info_goal(OldProc0, Goal0), 
 	Goal0 = _GoalExpr - GoalInfo0,
+
+		% We must use the declared determinism for determining
+		% the determinism of the version of the goal with its
+		% arguments removed.
+	proc_info_declared_determinism(OldProc0, MaybeDeterminism),
+	( MaybeDeterminism = yes(DeclaredDeterminism),
+		Determinism = DeclaredDeterminism
+	; MaybeDeterminism = no,
+		proc_info_inferred_determinism(OldProc0, Determinism)
+	),
+	goal_info_set_determinism(GoalInfo0, Determinism, GoalInfo1),
+
 	proc_info_vartypes(OldProc0, VarTypes0),
 	set__list_to_set(HeadVars, NonLocals),
 	map__apply_to_list(HeadVars, VarTypes0, VarTypeList),
@@ -992,7 +1004,7 @@
 	remove_listof_elements(HeadVars, 1, UnusedArgs, NewHeadVars),
 	GoalExpr = call(NewPredId, NewProcId, NewHeadVars,
 		      not_builtin, no, qualified(PredModule, PredName)),
-	Goal1 = GoalExpr - GoalInfo0,
+	Goal1 = GoalExpr - GoalInfo1,
 	implicitly_quantify_goal(Goal1, Varset0, VarTypes1,
 		NonLocals, Goal, Varset, VarTypes, _),
 	proc_info_set_goal(OldProc0, Goal, OldProc1),
Index: tests/valid/Mmakefile
===================================================================
RCS file: /home/staff/zs/imp/tests/valid/Mmakefile,v
retrieving revision 1.95
diff -u -r1.95 Mmakefile
--- tests/valid/Mmakefile	4 Jan 2002 05:56:40 -0000	1.95
+++ tests/valid/Mmakefile	12 Feb 2002 13:15:31 -0000
@@ -166,6 +166,7 @@
 	uniq_mode_inf_bug.m \
 	unreachable_code.m \
 	unused_args_test2.m \
+	unused_arg_determinism.m \
 	vn_float.m \
 	zero_arity.m
 
@@ -297,6 +298,7 @@
 MCFLAGS-typeclass_det_warning	= --halt-at-warn
 MCFLAGS-unify_typeinfo_bug	= -O3 --no-special-preds
 MCFLAGS-uniq_mode_inf_bug	= --infer-all
+MCFLAGS-unused_arg_determinism	= -O5 # --no-warn-inferred-erroneous
 MCFLAGS-vn_float		= -O5
 MCFLAGS-zero_arity		= --infer-modes
 
Index: tests/valid/unused_arg_determinism.exp
===================================================================
RCS file: tests/valid/unused_arg_determinism.exp
diff -N tests/valid/unused_arg_determinism.exp
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ tests/valid/unused_arg_determinism.exp	12 Feb 2002 13:12:16 -0000
@@ -0,0 +1,4 @@
+Uncaught exception:
+Software Error: sorry, `foo' not implemented
+for this target language (or compiler back-end).
+Stack dump not available in this grade.
Index: tests/valid/unused_arg_determinism.m
===================================================================
RCS file: tests/valid/unused_arg_determinism.m
diff -N tests/valid/unused_arg_determinism.m
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ tests/valid/unused_arg_determinism.m	12 Feb 2002 13:10:38 -0000
@@ -0,0 +1,25 @@
+	% foo is declared semidet but is actually erroneous.
+	% Unused argument elimination used to generate a call to the
+	% unused version in a model_det context instead of the correct
+	% model_semi context.
+:- module unused_arg_determinism.
+:- interface.
+:- import_module io.
+:- pred main(io__state::di, io__state::uo) is det.
+
+:- type t.
+:- func foo(t) = t.
+:- mode foo(in) = out is semidet.
+
+:- implementation.
+:- type t ---> t ; u.
+main -->
+	( { X = foo(t) } ->
+		io__write(X)
+	;
+		io__write_string("failure")
+	),
+	io__nl.
+
+foo(_) = _ :-
+	private_builtin__sorry("foo").

----
Peter Ross
PhD Student University of Melbourne
http://www.cs.mu.oz.au/~petdr/
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