dupok, gcc compile fix, sync and syscall asm fix

R=rsc
APPROVED=rsc
DELTA=27  (18 added, 0 deleted, 9 changed)
OCL=35503
CL=35505

3 files changed, 17 insertions, 4 deletions

diff --git a/src/cmd/5l/l.h b/src/cmd/5l/l.h
index 09fbda8c2..05a20bad3 100644
--- a/src/cmd/5l/l.h
+++ b/src/cmd/5l/l.h
@@ -123,6 +123,7 @@ struct	Sym
 	short	become;
 	short	frame;
 	uchar	subtype;
+	uchar	dupok;
 	uchar	reachable;
 	int32	value;
 	int32	sig;
diff --git a/src/cmd/5l/obj.c b/src/cmd/5l/obj.c
index 574d50648..45751e8c5 100644
--- a/src/cmd/5l/obj.c
+++ b/src/cmd/5l/obj.c
@@ -564,6 +564,8 @@ loop:
 		}
 		if(p->to.offset > s->value)
 			s->value = p->to.offset;
+		if(p->reg & DUPOK)
+			s->dupok = 1;
 		break;
 
 	case ADYNT:
@@ -627,10 +629,15 @@ loop:
 		break;
 
 	case ADATA:
+		// Assume that AGLOBL comes after ADATA.
+		// If we've seen an AGLOBL that said this sym was DUPOK,
+		// ignore any more ADATA we see, which must be
+		// redefinitions.
 		s = p->from.sym;
-		if(s == S) {
-			diag("DATA without a sym\n%P", p);
-			break;
+		if(s != S && s->dupok) {
+			if(debug['v'])
+				Bprint(&bso, "skipping %s in %s: dupok\n", s->name, pn);
+			goto loop;
 		}
 		if(s != S) {
 			p->dlink = s->data;
diff --git a/src/cmd/ld/lib.c b/src/cmd/ld/lib.c
index 0ca165417..208a55b44 100644
--- a/src/cmd/ld/lib.c
+++ b/src/cmd/ld/lib.c
@@ -561,10 +561,15 @@ find1(int32 l, int c)
 int
 find2(int32 l, int c)
 {
+	union {
+		int32 l;
+		short p[2];
+	} u;
 	short *p;
 	int i;
 
-	p = (short*)&l;
+	u.l = l;
+	p = u.p;
 	for(i=0; i<4; i+=2) {
 		if(((*p >> 8) & 0xff) == c)
 			return i;