for GCC4.6: fix a bunch of set-and-not-used errors.

R=rsc
CC=golang-dev
https://golang.org/cl/4406048

src/cmd/6g/reg.c

@@ -1193,7 +1193,6 @@ void
 paint1(Reg *r, int bn)
 {
 	Reg *r1;
-	Prog *p;
 	int z;
 	uint32 bb;
 
@@ -1219,7 +1218,6 @@ paint1(Reg *r, int bn)
 	}
 	for(;;) {
 		r->act.b[z] |= bb;
-		p = r->prog;
 
 		if(r->use1.b[z] & bb) {
 			change += CREF * r->loop;

src/cmd/6l/asm.c

@@ -681,7 +681,7 @@ asmb(void)
 {
 	int32 magic;
 	int a, dynsym;
-	vlong vl, va, startva, fo, w, symo, elfsymo, elfstro, elfsymsize, machlink;
+	vlong vl, startva, fo, symo, elfsymo, elfstro, elfsymsize, machlink;
 	ElfEhdr *eh;
 	ElfPhdr *ph, *pph;
 	ElfShdr *sh;
@@ -848,8 +848,6 @@ asmb(void)
 		eh = getElfEhdr();
 		fo = HEADR;
 		startva = INITTEXT - HEADR;
-		va = startva + fo;
-		w = segtext.filelen;
 
 		/* This null SHdr must appear before all others */
 		sh = newElfShdr(elfstr[ElfStrEmpty]);

src/cmd/6l/obj.c

@@ -389,7 +389,7 @@ ldobj1(Biobuf *f, char *pkg, int64 len, char *pn)
 	vlong ipc;
 	Prog *p;
 	int v, o, r, skip, mode;
-	Sym *h[NSYM], *s, *di;
+	Sym *h[NSYM], *s;
 	uint32 sig;
 	char *name, *x;
 	int ntext;
@@ -400,7 +400,6 @@ ldobj1(Biobuf *f, char *pkg, int64 len, char *pn)
 	lastp = nil;
 	ntext = 0;
 	eof = Boffset(f) + len;
-	di = S;
 	src[0] = 0;
 
 newloop:

src/cmd/gc/dcl.c

@@ -697,12 +697,10 @@ stotype(NodeList *l, int et, Type **t, int funarg)
 	Type *f, *t1, *t2, **t0;
 	Strlit *note;
 	int lno;
-	NodeList *init;
 	Node *n, *left;
 	char *what;
 
 	t0 = t;
-	init = nil;
 	lno = lineno;
 	what = "field";
 	if(et == TINTER)

src/cmd/gc/reflect.c

@@ -137,7 +137,6 @@ methodfunc(Type *f, Type *receiver)
 static Sig*
 methods(Type *t)
 {
-	int o;
 	Type *f, *mt, *it, *this;
 	Sig *a, *b;
 	Sym *method;
@@ -157,7 +156,6 @@ methods(Type *t)
 	// make list of methods for t,
 	// generating code if necessary.
 	a = nil;
-	o = 0;
 	oldlist = nil;
 	for(f=mt->xmethod; f; f=f->down) {
 		if(f->type->etype != TFUNC)
@@ -240,14 +238,12 @@ static Sig*
 imethods(Type *t)
 {
 	Sig *a, *all, *last;
-	int o;
 	Type *f;
 	Sym *method, *isym;
 	Prog *oldlist;
 
 	all = nil;
 	last = nil;
-	o = 0;
 	oldlist = nil;
 	for(f=t->type; f; f=f->down) {
 		if(f->etype != TFIELD)

src/cmd/gc/subr.c

@@ -660,12 +660,10 @@ nodbool(int b)
 Type*
 aindex(Node *b, Type *t)
 {
-	NodeList *init;
 	Type *r;
 	int bound;
 
 	bound = -1;	// open bound
-	init = nil;
 	typecheck(&b, Erv);
 	if(b != nil) {
 		switch(consttype(b)) {
@@ -1728,17 +1726,13 @@ isideal(Type *t)
 Type*
 methtype(Type *t)
 {
-	int ptr;
-
 	if(t == T)
 		return T;
 
 	// strip away pointer if it's there
-	ptr = 0;
 	if(isptr[t->etype]) {
 		if(t->sym != S)
 			return T;
-		ptr = 1;
 		t = t->type;
 		if(t == T)
 			return T;

src/cmd/gc/swt.c

@@ -250,7 +250,7 @@ newlabel(void)
 static void
 casebody(Node *sw, Node *typeswvar)
 {
-	Node *os, *oc, *n, *c, *last;
+	Node *n, *c, *last;
 	Node *def;
 	NodeList *cas, *stat, *l, *lc;
 	Node *go, *br;
@@ -263,8 +263,6 @@ casebody(Node *sw, Node *typeswvar)
 	cas = nil;	// cases
 	stat = nil;	// statements
 	def = N;	// defaults
-	os = N;		// last statement
-	oc = N;		// last case
 	br = nod(OBREAK, N, N);
 
 	for(l=sw->list; l; l=l->next) {

src/cmd/gc/walk.c

@@ -197,7 +197,6 @@ Node*
 walkdef(Node *n)
 {
 	int lno;
-	NodeList *init;
 	Node *e;
 	Type *t;
 	NodeList *l;
@@ -236,7 +235,6 @@ walkdef(Node *n)
 	if(n->type != T || n->sym == S)	// builtin or no name
 		goto ret;
 
-	init = nil;
 	switch(n->op) {
 	default:
 		fatal("walkdef %O", n->op);
@@ -380,14 +378,13 @@ walkstmt(Node **np)
 {
 	NodeList *init;
 	NodeList *ll, *rl;
-	int cl, lno;
+	int cl;
 	Node *n, *f;
 
 	n = *np;
 	if(n == N)
 		return;
 
-	lno = lineno;
 	setlineno(n);
 
 	switch(n->op) {

src/cmd/ld/data.c

@@ -878,7 +878,7 @@ textaddress(void)
 void
 address(void)
 {
-	Section *s, *text, *data, *rodata, *bss;
+	Section *s, *text, *data, *rodata;
 	Sym *sym, *sub;
 	uvlong va;
 
@@ -913,7 +913,6 @@ address(void)
 	text = segtext.sect;
 	rodata = segtext.sect->next;
 	data = segdata.sect;
-	bss = segdata.sect->next;
 
 	for(sym = datap; sym != nil; sym = sym->next) {
 		cursym = sym;

src/cmd/ld/ldelf.c

@@ -319,7 +319,7 @@ ldelf(Biobuf *f, char *pkg, int64 len, char *pn)
 	char *name;
 	int i, j, rela, is64, n;
 	uchar hdrbuf[64];
-	uchar *p, *dp;
+	uchar *p;
 	ElfHdrBytes *hdr;
 	ElfObj *obj;
 	ElfSect *sect, *rsect;
@@ -561,7 +561,6 @@ ldelf(Biobuf *f, char *pkg, int64 len, char *pn)
 		n = rsect->size/(4+4*is64)/(2+rela);
 		r = mal(n*sizeof r[0]);
 		p = rsect->base;
-		dp = sect->base;
 		for(j=0; j<n; j++) {
 			add = 0;
 			rp = &r[j];

src/cmd/ld/lib.c

@@ -1033,7 +1033,7 @@ mkfwd(void)
 	Prog *p;
 	int i;
 	int32 dwn[LOG], cnt[LOG];
-	Prog *lst[LOG], *last;
+	Prog *lst[LOG];
 
 	for(i=0; i<LOG; i++) {
 		if(i == 0)
@@ -1044,7 +1044,6 @@ mkfwd(void)
 		lst[i] = P;
 	}
 	i = 0;
-	last = nil;
 	for(cursym = textp; cursym != nil; cursym = cursym->next) {
 		for(p = cursym->text; p != P; p = p->link) {
 			if(p->link == P) {

src/libmach/executable.c

@@ -991,7 +991,6 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp)
 {
 	uvlong (*swav)(uvlong);
 	uint32 (*swal)(uint32);
-	ushort (*swab)(ushort);
 	Machhdr *mp;
 	MachCmd **cmd;
 	MachSymSeg *symtab;
@@ -1012,7 +1011,6 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp)
 		return 0;
 	}
 
-	swab = leswab;
 	swal = leswal;
 	swav = leswav;