diff for review - bug fix

[Simon TAYLOR]

Hi Fergus,

Here's a bug fix for review.

Simon


Estimated hours taken: 1

Fixed a bug reported by David Overton which caused an abort in the
second pass of simplification.

compiler/dead_proc_elim.m
	Remove unused pseudo_imported unification preds 
	(they can be inlined away).

compiler/hlds_out.m
	Invert the test for printing pseudo_imported unification preds 
	in hlds_dumps.

tests/valid/Mmake
tests/valid/compl_unify_bug.m
	Add a regression test.


Index: dead_proc_elim.m
===================================================================
RCS file: /home/staff/zs/imp/mercury/compiler/dead_proc_elim.m,v
retrieving revision 1.22
diff -u -r1.22 dead_proc_elim.m
--- dead_proc_elim.m	1997/02/14 05:53:56	1.22
+++ dead_proc_elim.m	1997/02/15 04:33:27
@@ -448,6 +448,7 @@
 		% If yes, find out also whether any of its procedures
 		% must be kept.
 		( Status = local, Keep = no
+		; Status = pseudo_imported, Keep = no
 		; Status = pseudo_exported, Keep = yes(0)
 		)
 	->
Index: hlds_out.m
===================================================================
RCS file: /home/staff/zs/imp/mercury/compiler/hlds_out.m,v
retrieving revision 1.155
diff -u -r1.155 hlds_out.m
--- hlds_out.m	1997/01/27 07:45:09	1.155
+++ hlds_out.m	1997/02/15 03:30:24
@@ -402,7 +402,7 @@
 			% mode for them
 			{ pred_info_is_pseudo_imported(PredInfo) },
 			{ pred_info_procids(PredInfo, ProcIds) },
-			{ ProcIds \= [0] }
+			{ ProcIds = [0] }
 		->
 			[]
 		;

Index: tests/valid/Mmake
===================================================================
RCS file: /home/staff/zs/imp/tests/valid/Mmake,v
retrieving revision 1.25
diff -u -r1.25 Mmake
--- Mmake	1997/02/10 04:06:06	1.25
+++ Mmake	1997/02/15 06:39:42
@@ -8,6 +8,7 @@
 
 SOURCES= \
 	complicated_unify.m \
+	compl_unify_bug.m \
 	constructor_arg_names.m \
 	dcg_test.m \
 	det_condition.m \
@@ -76,6 +77,10 @@
 simplify_bug.c:	simplify_bug.m
 	$(MCG) --grade $(GRADE) $(MCGFLAGS) -O-1 \
 		simplify_bug.m > simplify_bug.err 2>&1
+
+compl_unify_bug.c: compl_unify_bug.m
+	$(MCG) --grade $(GRADE) $(MCGFLAGS) -O3 \
+		compl_unify_bug.m > compl_unify_bug.err 2>&1
 
 vn_float.c: vn_float.m
 	$(MCG) --grade $(GRADE) $(MCGFLAGS) -O5 vn_float.m > vn_float.err 2>&1



tests/valid/compl_unify_bug.m 
-------------------------------------------------------------------------------
% This is a regression test for a bug in dead procedure elimination
% of pseudo-imported preds.
:- module compl_unify_bug.

:- interface.

:- pred bug(int::in, list(T)::in) is semidet.

:- implementation.

:- import_module list.

bug(NextInputArgNum, InputArgs) :-
	list__drop(NextInputArgNum, InputArgs, [_|_]).