From a92c8bf067d0e428dd3ec8539230fefe9d0b660e Mon Sep 17 00:00:00 2001
From: ceriel <none@none>
Date: Tue, 16 Dec 1986 15:22:33 +0000
Subject: [PATCH] D_BUSY added, to check recursive deps in def modules

---
 lang/m2/comp/def.H       | 5 ++---
 lang/m2/comp/defmodule.c | 6 +++++-
 lang/m2/comp/program.g   | 2 ++
 lang/m2/comp/type.c      | 2 +-
 4 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/lang/m2/comp/def.H b/lang/m2/comp/def.H
index d27f32c72..3462d4b25 100644
--- a/lang/m2/comp/def.H
+++ b/lang/m2/comp/def.H
@@ -97,7 +97,7 @@ struct def	{		/* list of definitions for a name */
 #define D_VALUE	(D_PROCEDURE|D_VARIABLE|D_FIELD|D_ENUM|D_CONST|D_PROCHEAD)
 #define D_ISTYPE	(D_HIDDEN|D_TYPE|D_FTYPE)
 #define is_type(dfx)	((dfx)->df_kind & D_ISTYPE)
-	char df_flags;
+	unsigned short  df_flags;
 #define D_NOREG		0x01	/* set if it may not reside in a register */
 #define D_USED		0x02	/* set if used (future use ???) */
 #define D_DEFINED	0x04	/* set if it is assigned a value (future use ???) */
@@ -105,6 +105,7 @@ struct def	{		/* list of definitions for a name */
 #define D_VALPAR	0x10	/* set if it is a value parameter */
 #define D_EXPORTED	0x20	/* set if exported */
 #define D_QEXPORTED	0x40	/* set if qualified exported */
+#define D_BUSY		0x80	/* set if busy reading this definition module */
 	struct type *df_type;
 	union {
 		struct module df_module;
@@ -120,8 +121,6 @@ struct def	{		/* list of definitions for a name */
 	} df_value;
 };
 
-#define SetUsed(df)	((df)->df_flags |= D_USED)
-
 /* ALLOCDEF "def" 50 */
 
 extern struct def
diff --git a/lang/m2/comp/defmodule.c b/lang/m2/comp/defmodule.c
index 2fe30eadc..d5f68767e 100644
--- a/lang/m2/comp/defmodule.c
+++ b/lang/m2/comp/defmodule.c
@@ -55,7 +55,7 @@ GetDefinitionModule(id, incr)
 		We may have to read the definition module itself.
 		Also increment level by "incr".
 	*/
-	struct def *df;
+	register struct def *df;
 	static int level;
 	struct scopelist *vis;
 
@@ -101,6 +101,10 @@ GetDefinitionModule(id, incr)
 			df->mod_vis = vis;
 		}
 	}
+	else if (df->df_flags & D_BUSY) {
+		error("definition module \"%s\" depends on itself",
+			id->id_text);
+	}
 	else if (df == Defined && level == 1) {
 		error("cannot import from currently defined module");
 		df->df_kind = D_ERROR;
diff --git a/lang/m2/comp/program.g b/lang/m2/comp/program.g
index 6867279d0..40d8113a2 100644
--- a/lang/m2/comp/program.g
+++ b/lang/m2/comp/program.g
@@ -121,6 +121,7 @@ DefinitionModule
 } :
 	DEFINITION
 	MODULE IDENT	{ df = define(dot.TOK_IDF, GlobalScope, D_MODULE);
+			  df->df_flags |= D_BUSY;
 			  if (!Defined) Defined = df;
 			  if (df->df_idf != DefId) {
 				error("DEFINITION MODULE name is not \"%s\"",
@@ -155,6 +156,7 @@ node_warning(exportlist, W_OLDFASHIONED, "export list in definition module ignor
 			  }
 			  DefinitionModule--;
 			  match_id(df->df_idf, dot.TOK_IDF);
+			  df->df_flags &= ~D_BUSY;
 			}
 	'.'
 ;
diff --git a/lang/m2/comp/type.c b/lang/m2/comp/type.c
index a7003717c..cea61145a 100644
--- a/lang/m2/comp/type.c
+++ b/lang/m2/comp/type.c
@@ -383,7 +383,7 @@ set_type(tp)
 	}
 
 	tp = construct_type(T_SET, tp);
-	tp->tp_size = WA(((ub - lb) + 8) >> 3);
+	tp->tp_size = WA((ub - lb + 8) >> 3);
 	return tp;
 }