fix type-punned pointer warnings from gcc

R=rsc
http://codereview.appspot.com/396042

src/cmd/acid/expr.c

@@ -855,11 +855,12 @@ ocand(Node *n, Node *res)
 {
 	Node l, r;
 
-	res->store.fmt = l.store.fmt;
+	res->store.fmt = 'D';
 	res->op = OCONST;
 	res->type = TINT;
 	res->store.u.ival = 0;
 	expr(n->left, &l);
+	res->store.fmt = l.store.fmt;
 	if(bool(&l) == 0)
 		return;
 	expr(n->right, &r);

src/cmd/db/format.c

@@ -60,7 +60,7 @@ exform(int fcount, int prt, char *ifp, Map *map, int literal, int firstpass)
 	char	*fp;
 	char	c, modifier;
 	int	i;
-	ushort sh, *sp;
+	ushort sh;
 	uchar ch, *cp;
 	Symbol s;
 	char buf[512];
@@ -205,7 +205,8 @@ exform(int fcount, int prt, char *ifp, Map *map, int literal, int firstpass)
 
 		case 'R':
 			if (literal) {
-				sp = (u16int*)(void*)˙
+				u16int sp[2];
+				memmove(&sp, &dot, 4);
 				dprint("%C%C", sp[0], sp[1]);
 				endline();
 				dotinc = 4;

src/cmd/vbackup/vnfs.c

@@ -322,10 +322,14 @@ cryptinit(void)
 {
 	uchar key[32], ivec[AESbsize];
 	int i;
+	u32int u32;
 	
-	*(u32int*)sessid = truerand();
+	u32 = truerand();
-	for(i=0; i<nelem(key); i+=4)
+	memmove(sessid, &u32, 4);
-		*(u32int*)&key[i] = truerand();
+	for(i=0; i<nelem(key); i+=4) {
+		u32 = truerand();
+		memmove(key+i, &u32, 4);
+	}
 	for(i=0; i<nelem(ivec); i++)
 		ivec[i] = fastrand();
 	setupAESstate(&aesstate, key, sizeof key, ivec);
@@ -793,6 +797,8 @@ cnodelookup(Ctree *t, Cnode **np, char *name)
 Nfs3Status
 cnodegetattr(Cnode *n, Nfs3Attr *attr)
 {
+	uint64 u64;
+
 	memset(attr, 0, sizeof *attr);
 	if(n->read){
 		attr->type = Nfs3FileReg;
@@ -805,7 +811,8 @@ cnodegetattr(Cnode *n, Nfs3Attr *attr)
 		attr->size = 1024;
 		attr->nlink = 10;
 	}
-	attr->fileid = *(u64int*)n->handle;
+	memmove(&u64, n->handle, 8);
+	attr->fileid = u64;
 	attr->atime.sec = n->mtime;
 	attr->mtime.sec = n->mtime;
 	attr->ctime.sec = n->mtime;
@@ -817,6 +824,7 @@ cnodereaddir(Cnode *n, u32int count, u64int cookie, uchar **pdata, u32int *pcoun
 {
 	uchar *data, *p, *ep, *np;
 	u64int c;
+	u64int u64;
 	Nfs3Entry ne;
 	
 	n = n->kidlist;
@@ -842,7 +850,8 @@ cnodereaddir(Cnode *n, u32int count, u64int cookie, uchar **pdata, u32int *pcoun
 		ne.name = n->name;
 		ne.namelen = strlen(n->name);
 		ne.cookie = ++cookie;
-		ne.fileid = *(u64int*)n->handle;
+		memmove(&u64, n->handle, 8);
+		ne.fileid = u64;
 		if(nfs3entrypack(p, ep, &np, &ne) < 0)
 			break;
 		p = np;

src/lib9/_p9dialparse.c

@@ -71,7 +71,7 @@ parseip(char *host, u32int *pip)
 			return -1;
 		break;
 	}
-	*pip = *(u32int*)addr;
+	memmove(pip, addr, 4);
 	return 0;
 }
 

src/lib9/sendfd.c

@@ -46,7 +46,7 @@ sendfd(int s, int fd)
 	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
 	cmsg->cmsg_level = SOL_SOCKET;
 	cmsg->cmsg_type = SCM_RIGHTS;
-	*(int*)CMSG_DATA(cmsg) = fd;
+	memmove(CMSG_DATA(cmsg), &fd, sizeof(int));
 
 	if((n=sendmsg(s, &msg, 0)) != iov.iov_len)
 		return -1;

src/lib9/truerand.c

@@ -6,6 +6,7 @@ truerand(void)
 {
 	int i, n;
 	uchar buf[sizeof(ulong)];
+	ulong x;
 	static int randfd = -1;
 	static char *randfile;
 
@@ -21,5 +22,6 @@ truerand(void)
 	for(i=0; i<sizeof(buf); i += n)
 		if((n = readn(randfd, buf+i, sizeof(buf)-i)) < 0)
 			sysfatal("can't read %s: %r", randfile);
-	return *((ulong*)buf);
+	memmove(&x, buf, sizeof x);
+	return x;
 }

src/libauthsrv/readnvram.c

@@ -76,8 +76,6 @@ readnvram(Nvrsafe *safep, int flag)
 	if(strcmp(cputype, "386")==0 || strcmp(cputype, "alpha")==0)
 		cputype = "pc";
 
-	safe = (Nvrsafe*)buf;
-
 	fd = -1;
 	safeoff = -1;
 	safelen = -1;
@@ -140,7 +138,7 @@ readnvram(Nvrsafe *safep, int flag)
 		memset(safep, 0, sizeof(*safep));
 		safe = safep;
 	}else{
-		*safep = *safe;
+		memmove(safep, buf, sizeof *safep);
 		safe = safep;
 
 		err |= check(safe->machkey, DESKEYLEN, safe->machsum, "bad nvram key");
@@ -163,7 +161,7 @@ readnvram(Nvrsafe *safep, int flag)
 		safe->configsum = nvcsum(safe->config, CONFIGLEN);
 		safe->authidsum = nvcsum(safe->authid, sizeof(safe->authid));
 		safe->authdomsum = nvcsum(safe->authdom, sizeof(safe->authdom));
-		*(Nvrsafe*)buf = *safe;
+		memmove(buf, safe, sizeof *safe);
 		if(seek(fd, safeoff, 0) < 0
 		|| write(fd, buf, safelen) != safelen){
 			fprint(2, "can't write key to nvram: %r\n");

src/libavl/avl.c

@@ -211,6 +211,7 @@ _deleteavl(Avl **tp, Avl *p, Avl *rx, int(*cmp)(Avl*,Avl*), Avl **del,
 	return -(ob != 0 && (*tp)->bal == 0);
 }
 
+/*
 static void
 checkparents(Avl *a, Avl *p)
 {
@@ -221,6 +222,7 @@ checkparents(Avl *a, Avl *p)
 	checkparents(a->n[0], a);
 	checkparents(a->n[1], a);
 }
+*/
 
 struct Avltree
 {
@@ -403,6 +405,7 @@ endwalk(Avlwalk *w)
 	free(w);
 }
 
+/*
 static void
 walkavl(Avl *t, void (*f)(Avl*, void*), void *v)
 {
@@ -412,3 +415,4 @@ walkavl(Avl *t, void (*f)(Avl*, void*), void *v)
 	f(t, v);
 	walkavl(t->n[1], f, v);
 }
+*/

src/libip/udp.c

@@ -21,8 +21,8 @@ udpread(int fd, Udphdr *hdr, void *buf, long n)
 	}
 	memset(hdr, 0, sizeof *hdr);
 	memmove(hdr->laddr, v4prefix, IPaddrlen);
-	*(u32int*)(hdr->laddr+12) = *(u32int*)&sin.sin_addr;
+	memmove(hdr->laddr+12, &sin.sin_addr, sizeof(u32int));
-	*(u16int*)hdr->lport = *(u16int*)&sin.sin_port;
+	memmove(hdr->lport, &sin.sin_port, sizeof(u16int));
 
 	len = sizeof sin;
 	n = recvfrom(fd, buf, n, 0, (struct sockaddr*)&sin, &len);
@@ -33,8 +33,8 @@ udpread(int fd, Udphdr *hdr, void *buf, long n)
 		return -1;
 	}
 	memmove(hdr->raddr, v4prefix, IPaddrlen);
-	*(u32int*)(hdr->raddr+12) = *(u32int*)&sin.sin_addr;
+	memmove(hdr->raddr+12, &sin.sin_addr, sizeof(u32int));
-	*(u16int*)hdr->rport = *(u16int*)&sin.sin_port;
+	memmove(hdr->rport, &sin.sin_port, sizeof(u16int));
 
 	return n;
 }

src/libmach/Linux.c

@@ -146,7 +146,7 @@ ptracerw(int type, int xtype, int isr, int pid, ulong addr, void *v, uint n)
 			if(n-i >= 4)
 				*(u32int*)((char*)v+i) = u;
 			else{
-				*(u32int*)buf = u;
+				memmove(buf, &u, 4);
 				memmove((char*)v+i, buf, n-i);
 			}
 		}else{
@@ -157,9 +157,9 @@ ptracerw(int type, int xtype, int isr, int pid, ulong addr, void *v, uint n)
 				u = ptrace(xtype, pid, addr+i, 0);
 				if(errno)
 					return -1;
-				*(u32int*)buf = u;
+				memmove(buf, &u, 4);
 				memmove(buf, (char*)v+i, n-i);
-				u = *(u32int*)buf;
+				memmove(&u, buf, 4);
 			}
 			if(ptrace(type, pid, addr+i, u) < 0)
 				goto ptraceerr;

src/libmemdraw/draw.c

@@ -2109,6 +2109,7 @@ memoptdraw(Memdrawparam *par)
 {
 	int m, y, dy, dx, op;
 	u32int v;
+	u16int u16;
 	Memimage *src;
 	Memimage *dst;
 
@@ -2198,7 +2199,8 @@ DBG print("dp %p v %lux lm %ux (v ^ *dp) & lm %lux\n", dp, v, lm, (v^*dp)&lm);
 		case 16:
 			p[0] = v;		/* make little endian */
 			p[1] = v>>8;
-			v = *(ushort*)p;
+			memmove(&u16, p, 2);
+			v = u16;
 DBG print("dp=%p; dx=%d; for(y=0; y<%d; y++, dp+=%d)\nmemsets(dp, v, dx);\n",
 	dp, dx, dy, dwid);
 			for(y=0; y<dy; y++, dp+=dwid)
@@ -2213,7 +2215,7 @@ DBG print("dp=%p; dx=%d; for(y=0; y<%d; y++, dp+=%d)\nmemsets(dp, v, dx);\n",
 			p[1] = v>>8;
 			p[2] = v>>16;
 			p[3] = v>>24;
-			v = *(u32int*)p;
+			memmove(&v, p, 4);
 			for(y=0; y<dy; y++, dp+=dwid)
 				memsetl(dp, v, dx);
 			return 1;
@@ -2371,6 +2373,13 @@ chardraw(Memdrawparam *par)
 	uchar sp[4];
 	Rectangle r, mr;
 	Memimage *mask, *src, *dst;
+	union {
+		// black box to hide pointer conversions from gcc.
+		// we'll see how long this works.
+		uchar *u8;
+		u16int *u16;
+		u32int *u32;
+	} gcc_black_box;
 
 if(0) if(drawdebug) iprint("chardraw? mf %lux md %d sf %lux dxs %d dys %d dd %d ddat %p sdat %p\n",
 		par->mask->flags, par->mask->depth, par->src->flags, 
@@ -2443,8 +2452,10 @@ DBG print("bits %lux sh %d...", bits, i);
 			}
 			break;
 		case 16:
-			ws = (ushort*)wp;
+			gcc_black_box.u8 = wp;
-			v = *(ushort*)sp;
+			ws = gcc_black_box.u16;
+			gcc_black_box.u8 = sp;
+			v = *gcc_black_box.u16;
 			for(x=bx; x>ex; x--, ws++){
 				i = x&7;
 				if(i == 8-1)
@@ -2469,8 +2480,10 @@ DBG print("bits %lux sh %d...", bits, i);
 			}
 			break;
 		case 32:
-			wl = (u32int*)wp;
+			gcc_black_box.u8 = wp;
-			v = *(u32int*)sp;
+			wl = gcc_black_box.u32;
+			gcc_black_box.u8 = sp;
+			v = *gcc_black_box.u32;
 			for(x=bx; x>ex; x--, wl++){
 				i = x&7;
 				if(i == 8-1)
@@ -2537,7 +2550,7 @@ _memfillcolor(Memimage *i, u32int val)
 		p[1] = bits>>8;
 		p[2] = bits>>16;
 		p[3] = bits>>24;
-		bits = *(u32int*)p;
+		memmove(&bits, p, 4);
 		memsetl(wordaddr(i, i->r.min), bits, i->width*Dy(i->r));
 		break;
 	}