From 3af275f8d652d1a8fd03a884e0f4fb701a0d1315 Mon Sep 17 00:00:00 2001
From: ceriel <none@none>
Date: Wed, 22 Jul 1987 17:02:54 +0000
Subject: [PATCH] A different way of detecting conformant arrays

---
 lang/m2/comp/chk_expr.c | 17 +++++------------
 lang/m2/comp/declar.g   |  5 ++++-
 lang/m2/comp/type.H     |  2 +-
 3 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/lang/m2/comp/chk_expr.c b/lang/m2/comp/chk_expr.c
index 2bf6fec87..0f4787243 100644
--- a/lang/m2/comp/chk_expr.c
+++ b/lang/m2/comp/chk_expr.c
@@ -128,10 +128,9 @@ ChkArr(expp)
 	/* Type of the index must be assignment compatible with
 	   the index type of the array (Def 8.1).
 	   However, the index type of a conformant array is not specified.
-	   Either INTEGER or CARDINAL seems reasonable.
+	   In our implementation it is CARDINAL.
 	*/
-	if (IsConformantArray(tpl) ? !TstAssCompat(card_type, tpr)
-				   : !TstAssCompat(IndexType(tpl), tpr)) {
+	if (!TstAssCompat(IndexType(tpl), tpr)) {
 		node_error(expp, "incompatible index type");
 		return 0;
 	}
@@ -983,17 +982,11 @@ ChkStandard(expp, left)
 		if (!(left = getarg(&arg, T_ARRAY|T_STRING|T_CHAR, 0, edf))) {
 			return 0;
 		}
-		if (IsConformantArray(left->nd_type)) {
-			/* A conformant array has no explicit index type,
-			   but it is a subrange with lower bound 0, so
-			   it is of type CARDINAL !!!
-			*/
-			expp->nd_type = card_type;
-			break;
-		}
 		if (left->nd_type->tp_fund == T_ARRAY) {
 			expp->nd_type = IndexType(left->nd_type);
-			cstcall(expp, S_MAX);
+			if (! IsConformantArray(left->nd_type)) {
+				cstcall(expp, S_MAX);
+			}
 			break;
 		}
 		if (left->nd_symb != STRING) {
diff --git a/lang/m2/comp/declar.g b/lang/m2/comp/declar.g
index d6f89c3d1..4da0391ad 100644
--- a/lang/m2/comp/declar.g
+++ b/lang/m2/comp/declar.g
@@ -143,7 +143,10 @@ FormalType(struct type **ptp;)
 	extern arith ArrayElSize();
 } :
 	ARRAY OF qualtype(ptp)
-		{ register struct type *tp = construct_type(T_ARRAY, NULLTYPE);
+		{ /* index type of conformant array is "CARDINAL".
+		     Recognize a conformant array by size 0.
+		  */
+		  register struct type *tp = construct_type(T_ARRAY, card_type);
 
 		  tp->arr_elem = *ptp;
 		  *ptp = tp;
diff --git a/lang/m2/comp/type.H b/lang/m2/comp/type.H
index 767d7fab3..b5448064a 100644
--- a/lang/m2/comp/type.H
+++ b/lang/m2/comp/type.H
@@ -152,7 +152,7 @@ struct type
 
 #define NULLTYPE ((struct type *) 0)
 
-#define IsConformantArray(tpx)	((tpx)->tp_fund==T_ARRAY && (tpx)->tp_next==0)
+#define IsConformantArray(tpx)	((tpx)->tp_fund==T_ARRAY && (tpx)->tp_size==0)
 #define bounded(tpx)		((tpx)->tp_fund & T_INDEX)
 #define complex(tpx)		((tpx)->tp_fund & (T_RECORD|T_ARRAY))
 #define WA(sz)			(align(sz, (int) word_size))