From: Ken Thompson <ken@golang.org>
Date: Fri, 19 Dec 2008 22:04:25 +0000 (-0800)
Subject: portability bug
X-Git-Tag: weekly.2009-11-06~2469
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=6fa74e09736dbe70269ae016dbd05e3fda994965;p=gostls13.git

portability bug
cant assign to closed array

R=r
OCL=21634
CL=21634
---

diff --git a/src/cmd/6g/align.c b/src/cmd/6g/align.c
index 392ad3d0c4..2a930523b4 100644
--- a/src/cmd/6g/align.c
+++ b/src/cmd/6g/align.c
@@ -151,7 +151,7 @@ dowidth(Type *t)
 		if(t->type == T)
 			break;
 		dowidth(t->type);
-		w = sizeof(Array);
+		w = sizeof_Array;
 		if(t->bound >= 0)
 			w = t->bound * t->type->width;
 		break;
@@ -259,5 +259,10 @@ belexinit(int lextype)
 
 	symstringo = lookup(".stringo");	// strings
 
+	Array_array = rnd(0, types[tptr]->width);
+	Array_nel = rnd(Array_array+types[tptr]->width, types[TUINT32]->width);
+	Array_cap = rnd(Array_nel+types[TUINT32]->width, types[TUINT32]->width);
+	sizeof_Array = rnd(Array_cap+types[TUINT32]->width, maxround);
+
 	listinit();
 }
diff --git a/src/cmd/6g/cgen.c b/src/cmd/6g/cgen.c
index bb5cb24612..c0a665c072 100644
--- a/src/cmd/6g/cgen.c
+++ b/src/cmd/6g/cgen.c
@@ -189,14 +189,14 @@ cgen(Node *n, Node *res)
 			// convert dynamic array to static array
 			n2 = n1;
 			n2.op = OINDREG;
-			n2.xoffset = offsetof(Array,array);
+			n2.xoffset = Array_array;
 			n2.type = types[tptr];
 			gins(AMOVQ, &n2, &n1);
 		}
 		if(isptrdarray(n->type) && isptrsarray(nl->type)) {
 			// conver static array to dynamic array
 			// it is assumed that the dope is just before the array
-			nodconst(&n2, types[tptr], sizeof(Array));
+			nodconst(&n2, types[tptr], sizeof_Array);
 			gins(ASUBQ, &n2, &n1);
 		}
 		gmove(&n1, res);
@@ -247,7 +247,7 @@ cgen(Node *n, Node *res)
 			cgen(nl, &n1);
 			n1.op = OINDREG;
 			n1.type = types[TUINT32];
-			n1.xoffset = offsetof(Array,nel);
+			n1.xoffset = Array_nel;
 			gmove(&n1, res);
 			regfree(&n1);
 			break;
@@ -257,7 +257,7 @@ cgen(Node *n, Node *res)
 			agen(nl, &n1);
 			n1.op = OINDREG;
 			n1.type = types[TUINT32];
-			n1.xoffset = offsetof(Array,nel);
+			n1.xoffset = Array_nel;
 			gmove(&n1, res);
 			regfree(&n1);
 			break;
@@ -271,7 +271,7 @@ cgen(Node *n, Node *res)
 			cgen(nl, &n1);
 			n1.op = OINDREG;
 			n1.type = types[TUINT32];
-			n1.xoffset = offsetof(Array,cap);
+			n1.xoffset = Array_cap;
 			gmove(&n1, res);
 			regfree(&n1);
 			break;
@@ -281,7 +281,7 @@ cgen(Node *n, Node *res)
 			agen(nl, &n1);
 			n1.op = OINDREG;
 			n1.type = types[TUINT32];
-			n1.xoffset = offsetof(Array,cap);
+			n1.xoffset = Array_cap;
 			gmove(&n1, res);
 			regfree(&n1);
 			break;
@@ -491,7 +491,7 @@ agen(Node *n, Node *res)
 					n1 = n3;
 					n1.op = OINDREG;
 					n1.type = types[tptr];
-					n1.xoffset = offsetof(Array, nel);
+					n1.xoffset = Array_nel;
 					nodconst(&n2, types[TUINT64], v);
 					gins(optoas(OCMP, types[TUINT32]), &n1, &n2);
 					p1 = gbranch(optoas(OGT, types[TUINT32]), T);
@@ -502,7 +502,7 @@ agen(Node *n, Node *res)
 				n1 = n3;
 				n1.op = OINDREG;
 				n1.type = types[tptr];
-				n1.xoffset = offsetof(Array, array);
+				n1.xoffset = Array_array;
 				gmove(&n1, &n3);
 			} else
 			if(!debug['B']) {
@@ -540,7 +540,7 @@ agen(Node *n, Node *res)
 				n1 = n3;
 				n1.op = OINDREG;
 				n1.type = types[tptr];
-				n1.xoffset = offsetof(Array, nel);
+				n1.xoffset = Array_nel;
 			} else {
 				nodconst(&n1, types[TUINT64], nl->type->bound);
 				if(isptrsarray(nl->type))
@@ -556,7 +556,7 @@ agen(Node *n, Node *res)
 			n1 = n3;
 			n1.op = OINDREG;
 			n1.type = types[tptr];
-			n1.xoffset = offsetof(Array, array);
+			n1.xoffset = Array_array;
 			gmove(&n1, &n3);
 		}
 
@@ -756,7 +756,7 @@ bgen(Node *n, int true, Prog *to)
 			agen(nl, &n1);
 			n2 = n1;
 			n2.op = OINDREG;
-			n2.xoffset = offsetof(Array,array);
+			n2.xoffset = Array_array;
 			nodconst(&tmp, types[tptr], 0);
 			gins(optoas(OCMP, types[tptr]), &n2, &tmp);
 			patch(gbranch(a, types[tptr]), to);
diff --git a/src/cmd/6g/gg.h b/src/cmd/6g/gg.h
index 80a548f8aa..8d44d67d4a 100644
--- a/src/cmd/6g/gg.h
+++ b/src/cmd/6g/gg.h
@@ -119,6 +119,22 @@ EXTERN	Node*	newproc;
 EXTERN	Node*	throwindex;
 EXTERN	Node*	throwreturn;
 
+/*
+ * note this is the runtime representation
+ * of the compilers arrays.
+ *
+ * typedef	struct
+ * {				// must not move anything
+ * 	uchar	array[8];	// pointer to data
+ * 	uchar	nel[4];		// number of elements
+ * 	uchar	cap[4];		// allocated number of elements
+ * } Array;
+ */
+EXTERN	int	Array_array;	// runtime offsetof(Array,array)
+EXTERN	int	Array_nel;	// runtime offsetof(Array,nel)
+EXTERN	int	Array_cap;	// runtime offsetof(Array,cap)
+EXTERN	int	sizeof_Array;	// runtime sizeof(Array)
+
 /*
  * gen.c
  */
diff --git a/src/cmd/6g/gsubr.c b/src/cmd/6g/gsubr.c
index daaf713212..e19e85d5fe 100644
--- a/src/cmd/6g/gsubr.c
+++ b/src/cmd/6g/gsubr.c
@@ -1965,7 +1965,7 @@ oindex:
 			n2 = *reg;
 			n2.op = OINDREG;
 			n2.type = types[tptr];
-			n2.xoffset = offsetof(Array, nel);
+			n2.xoffset = Array_nel;
 		} else {
 			nodconst(&n2, types[TUINT64], l->type->bound);
 			if(o & OPtrto)
@@ -1981,7 +1981,7 @@ oindex:
 		n2 = *reg;
 		n2.op = OINDREG;
 		n2.type = types[tptr];
-		n2.xoffset = offsetof(Array, array);
+		n2.xoffset = Array_array;
 		gmove(&n2, reg);
 	}
 
@@ -2011,7 +2011,7 @@ oindex_const:
 			n1 = *reg;
 			n1.op = OINDREG;
 			n1.type = types[tptr];
-			n1.xoffset = offsetof(Array, nel);
+			n1.xoffset = Array_nel;
 			nodconst(&n2, types[TUINT64], v);
 			gins(optoas(OCMP, types[TUINT32]), &n1, &n2);
 			p1 = gbranch(optoas(OGT, types[TUINT32]), T);
@@ -2022,7 +2022,7 @@ oindex_const:
 		n1 = *reg;
 		n1.op = OINDREG;
 		n1.type = types[tptr];
-		n1.xoffset = offsetof(Array, array);
+		n1.xoffset = Array_array;
 		gmove(&n1, reg);
 
 	} else
diff --git a/src/cmd/gc/go.h b/src/cmd/gc/go.h
index 6cd2eab5a6..c0faddd478 100644
--- a/src/cmd/gc/go.h
+++ b/src/cmd/gc/go.h
@@ -61,20 +61,6 @@ struct	String
 	char	s[3];	// variable
 };
 
-/*
- * note this is the runtime representation
- * of the compilers arrays. it is probably
- * insafe to use it this way, but it puts
- * all the changes in one place.
- */
-typedef	struct	Array	Array;
-struct	Array
-{				// must not move anything
-	uchar	array[8];	// pointer to data
-	uchar	nel[4];		// number of elements
-	uchar	cap[4];		// allocated number of elements
-};
-
 /*
  * note this is the runtime representation
  * of hashmap iterator. it is probably
diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index 35d062524c..be0dd25505 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -1873,6 +1873,8 @@ ascompat(Type *t1, Type *t2)
 //	if(eqtype(t2, nilptr, 0))
 //		return 1;
 
+	if(issarray(t1))
+		return 0;
 	if(isnilinter(t1))
 		return 1;
 	if(isinter(t1)) {