[m-dev.] diff: fix undefined modes bug

[Fergus Henderson]

Estimated hours taken: 1.5

Fix a bug reported by Peter Ross <peter.ross at miscrit.be> where
for certain invalid code the compiler would, after correctly reporting
an error message, throw an exception.

compiler/typecheck.m:
	For predicates that have type errors, don't call
	post_typecheck__finish_ill_typed_pred, since (a) it's not
	needed any more, and (b) if there are undefined modes,
	post_typecheck__finish_ill_typed_pred can end up calling
	error/1.

tests/invalid/Mmakefile:
tests/invalid/undef_mode_and_no_clauses.m:
tests/invalid/undef_mode_and_no_clauses.err_exp:
	A regression test.

Workspace: /home/pgrad/fjh/ws/hg
Index: compiler/typecheck.m
===================================================================
RCS file: /home/mercury1/repository/mercury/compiler/typecheck.m,v
retrieving revision 1.278
diff -u -d -r1.278 typecheck.m
--- compiler/typecheck.m	2000/08/09 07:47:57	1.278
+++ compiler/typecheck.m	2000/09/15 23:54:33
@@ -158,7 +158,6 @@
 
 :- implementation.
 
-:- import_module post_typecheck.
 :- import_module hlds_goal, prog_util, type_util, modules, code_util.
 :- import_module prog_io, prog_io_util, prog_out, hlds_out, error_util.
 :- import_module mercury_to_mercury, mode_util, options, getopt, globals.
@@ -276,6 +275,15 @@
 				ModuleInfo2) }
 		;
 			{ Error1 = yes },
+		/********************
+		This code is not needed at the moment,
+		since currently we don't run mode analysis if
+		there are any type errors.
+		And this code also causes problems:
+		if there are undefined modes,
+		this code can end up calling error/1,
+		since post_typecheck__finish_ill_typed_pred
+		assumes that there are no undefined modes.
 			%
 			% if we get an error, we need to call
 			% post_typecheck__finish_ill_typed_pred on the
@@ -288,6 +296,8 @@
 			post_typecheck__finish_ill_typed_pred(ModuleInfo0,
 				PredId, PredInfo1, PredInfo),
 			{ map__det_update(Preds0, PredId, PredInfo, Preds) },
+		*******************/
+			{ map__det_update(Preds0, PredId, PredInfo1, Preds) },
 			{ module_info_set_preds(ModuleInfo0, Preds,
 				ModuleInfo1) },
 			{ module_info_remove_predid(ModuleInfo1, PredId,
Index: tests/invalid/Mmakefile
===================================================================
RCS file: /home/mercury1/repository/tests/invalid/Mmakefile,v
retrieving revision 1.68
diff -u -d -r1.68 Mmakefile
--- tests/invalid/Mmakefile	2000/09/15 23:45:48	1.68
+++ tests/invalid/Mmakefile	2000/09/15 23:59:57
@@ -86,6 +86,7 @@
 	unbound_inst_var.m \
 	undef_lambda_mode.m \
 	undef_mode.m \
+	undef_mode_and_no_clauses.m \
 	undef_mod_qual.m \
 	undef_symbol.m \
 	undef_type.m \
Index: tests/invalid/undef_mode_and_no_clauses.err_exp
===================================================================
RCS file: undef_mode_and_no_clauses.err_exp
diff -N undef_mode_and_no_clauses.err_exp
--- /dev/null	Thu Mar 30 14:06:13 2000
+++ undef_mode_and_no_clauses.err_exp	Sat Sep 16 10:59:32 2000
@@ -0,0 +1,5 @@
+undef_mode_and_no_clauses.m:012: In mode declaration for predicate `undef_mode_and_no_clauses:p'/2:
+undef_mode_and_no_clauses.m:012:   error: undefined mode `result'/1.
+undef_mode_and_no_clauses.m:011: Error: no clauses for
+undef_mode_and_no_clauses.m:011:   predicate `undef_mode_and_no_clauses:p/2'.
+For more information, try recompiling with `-E'.
Index: tests/invalid/undef_mode_and_no_clauses.m
===================================================================
RCS file: undef_mode_and_no_clauses.m
diff -N undef_mode_and_no_clauses.m
--- /dev/null	Thu Mar 30 14:06:13 2000
+++ undef_mode_and_no_clauses.m	Thu Jul 20 17:44:43 2000
@@ -0,0 +1,14 @@
+% This is a regression test for a bug that showed up in
+% version rotd-2000-08-12.
+% After correctly reporting the errors in this code,
+% the compiler threw an exception.
+
+:- module undef_mode_and_no_clauses.
+:- interface.
+:- type result(T) ---> ok(T).
+:- implementation.
+
+:- pred p(pred(T), result(T)).
+:- mode p(pred(out) is det, result(T)) is det.	% mode result/1 not defined
+
+% no clauses for p/2

-- 
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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