liblink: remove some gotos + other fixes

Rewrite gotos that violate Go's stricter rules.
Use uchar* instead of char* in a few places that aren't strings.
Remove dead opcross code from asm5.c.
Declare regstr (in both list6 and list8) static.

LGTM=minux, dave
R=minux, dave
CC=golang-codereviews
https://golang.org/cl/113230043

include/link.h

@@ -105,8 +105,8 @@ struct	Prog
 	int32	spadj;
 	uchar	mark;
 	uchar	back;	// 6l, 8l
-	char	ft;	/* 6l, 8l oclass cache */
-	char	tt;	// 6l, 8l
+	uchar	ft;	/* 6l, 8l oclass cache */
+	uchar	tt;	// 6l, 8l
 	uchar	optab;	// 5l
 	uchar	isize;	// 6l, 8l
 

src/liblink/asm5.c

@@ -394,10 +394,8 @@ static int32	immrot(uint32);
 static int32	immaddr(int32);
 static int32	opbra(Link*, int, int);
 
-static	Opcross	opcross[8];
 static	Oprang	oprange[ALAST];
-static	char	xcmp[C_GOK+1][C_GOK+1];
-static	uchar	repop[ALAST];
+static	uchar	xcmp[C_GOK+1][C_GOK+1];
 
 static Prog zprg = {
 	.as = AGOK,
@@ -811,8 +809,8 @@ span5(Link *ctxt, LSym *cursym)
 			if(m % 4 != 0 || p->pc % 4 != 0) {
 				ctxt->diag("pc invalid: %P size=%d", p, m);
 			}
-			if(m > sizeof(out))
-				ctxt->diag("instruction size too large: %d > %d", m, sizeof(out));
+			if(m/4 > nelem(out))
+				ctxt->diag("instruction size too large: %d > %d", m/4, nelem(out));
 			if(m == 0 && (p->as != AFUNCDATA && p->as != APCDATA && p->as != ADATABUNDLEEND)) {
 				if(p->as == ATEXT) {
 					ctxt->autosize = p->to.offset + 4;
@@ -1068,6 +1066,8 @@ immhalf(int32 v)
 	return 0;
 }
 
+static int aconsize(Link *ctxt);
+
 static int
 aclass(Link *ctxt, Addr *a)
 {
@@ -1179,7 +1179,7 @@ aclass(Link *ctxt, Addr *a)
 		case D_NONE:
 			ctxt->instoffset = a->offset;
 			if(a->reg != NREG)
-				goto aconsize;
+				return aconsize(ctxt);
 
 			t = immrot(ctxt->instoffset);
 			if(t)
@@ -1199,15 +1199,11 @@ aclass(Link *ctxt, Addr *a)
 
 		case D_AUTO:
 			ctxt->instoffset = ctxt->autosize + a->offset;
-			goto aconsize;
+			return aconsize(ctxt);
 
 		case D_PARAM:
 			ctxt->instoffset = ctxt->autosize + a->offset + 4L;
-		aconsize:
-			t = immrot(ctxt->instoffset);
-			if(t)
-				return C_RACON;
-			return C_LACON;
+			return aconsize(ctxt);
 		}
 		return C_GOK;
 
@@ -1217,6 +1213,17 @@ aclass(Link *ctxt, Addr *a)
 	return C_GOK;
 }
 
+static int
+aconsize(Link *ctxt)
+{
+	int t;
+
+	t = immrot(ctxt->instoffset);
+	if(t)
+		return C_RACON;
+	return C_LACON;
+}
+
 static void
 prasm(Prog *p)
 {
@@ -1227,7 +1234,7 @@ static Optab*
 oplook(Link *ctxt, Prog *p)
 {
 	int a1, a2, a3, r;
-	char *c1, *c3;
+	uchar *c1, *c3;
 	Optab *o, *e;
 
 	a1 = p->optab;
@@ -1251,11 +1258,6 @@ oplook(Link *ctxt, Prog *p)
 	r = p->as;
 	o = oprange[r].start;
 	if(o == 0) {
-		a1 = opcross[repop[r]][a1][a2][a3];
-		if(a1) {
-			p->optab = a1+1;
-			return optab+a1;
-		}
 		o = oprange[r].stop; /* just generate an error */
 	}
 	if(0 /*debug['O']*/) {
@@ -1527,6 +1529,8 @@ buildop(Link *ctxt)
 	}
 }
 
+static int32 mov(Link*, Prog*);
+
 static void
 asmout(Link *ctxt, Prog *p, Optab *o, int32 *out)
 {
@@ -1584,19 +1588,7 @@ if(0 /*debug['G']*/) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->na
 		break;
 
 	case 3:		/* add R<<[IR],[R],R */
-	mov:
-		aclass(ctxt, &p->from);
-		o1 = oprrr(ctxt, p->as, p->scond);
-		o1 |= p->from.offset;
-		rt = p->to.reg;
-		r = p->reg;
-		if(p->to.type == D_NONE)
-			rt = 0;
-		if(p->as == AMOVW || p->as == AMVN)
-			r = 0;
-		else if(r == NREG)
-			r = rt;
-		o1 |= (r<<16) | (rt<<12);
+		o1 = mov(ctxt, p);
 		break;
 
 	case 4:		/* add $I,[R],R */
@@ -1869,19 +1861,23 @@ if(0 /*debug['G']*/) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->na
 		o1 |= p->from.reg << 0;
 		break;
 
-	case 38:	/* movm $con,oreg -> stm */
-		o1 = (0x4 << 25);
-		o1 |= p->from.offset & 0xffff;
-		o1 |= p->to.reg << 16;
-		aclass(ctxt, &p->to);
-		goto movm;
-
-	case 39:	/* movm oreg,$con -> ldm */
-		o1 = (0x4 << 25) | (1 << 20);
-		o1 |= p->to.offset & 0xffff;
-		o1 |= p->from.reg << 16;
-		aclass(ctxt, &p->from);
-	movm:
+	case 38:
+	case 39:
+		switch(o->type) {
+		case 38:	/* movm $con,oreg -> stm */
+			o1 = (0x4 << 25);
+			o1 |= p->from.offset & 0xffff;
+			o1 |= p->to.reg << 16;
+			aclass(ctxt, &p->to);
+			break;
+	
+		case 39:	/* movm oreg,$con -> ldm */
+			o1 = (0x4 << 25) | (1 << 20);
+			o1 |= p->to.offset & 0xffff;
+			o1 |= p->from.reg << 16;
+			aclass(ctxt, &p->from);
+			break;
+		}
 		if(ctxt->instoffset != 0)
 			ctxt->diag("offset must be zero in MOVM; %P", p);
 		o1 |= (p->scond & C_SCOND) << 28;
@@ -1989,7 +1985,8 @@ if(0 /*debug['G']*/) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->na
 		if(p->from.reg == NREG) {
 			if(p->as != AMOVW)
 				ctxt->diag("byte MOV from shifter operand");
-			goto mov;
+			o1 = mov(ctxt, p);
+			break;
 		}
 		if(p->from.offset&(1<<4))
 			ctxt->diag("bad shift in LDR");
@@ -2001,7 +1998,8 @@ if(0 /*debug['G']*/) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->na
 	case 60:	/* movb R(R),R -> ldrsb indexed */
 		if(p->from.reg == NREG) {
 			ctxt->diag("byte MOV from shifter operand");
-			goto mov;
+			o1 = mov(ctxt, p);
+			break;
 		}
 		if(p->from.offset&(~0xf))
 			ctxt->diag("bad shift in LDRSB");
@@ -2358,6 +2356,27 @@ if(0 /*debug['G']*/) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->na
 	return;
 }
 
+static int32
+mov(Link *ctxt, Prog *p)
+{
+	int32 o1;
+	int rt, r;
+
+	aclass(ctxt, &p->from);
+	o1 = oprrr(ctxt, p->as, p->scond);
+	o1 |= p->from.offset;
+	rt = p->to.reg;
+	r = p->reg;
+	if(p->to.type == D_NONE)
+		rt = 0;
+	if(p->as == AMOVW || p->as == AMVN)
+		r = 0;
+	else if(r == NREG)
+		r = rt;
+	o1 |= (r<<16) | (rt<<12);
+	return o1;
+}
+
 static int32
 oprrr(Link *ctxt, int a, int sc)
 {

src/liblink/asm6.c

@@ -60,8 +60,6 @@ enum
 	FuncAlign = 16
 };
 
-extern char *anames6[];
-
 typedef	struct	Optab	Optab;
 typedef	struct	Movtab	Movtab;
 
@@ -187,7 +185,7 @@ enum
 	Maxand	= 10,		/* in -a output width of the byte codes */
 };
 
-static char ycover[Ymax*Ymax];
+static uchar ycover[Ymax*Ymax];
 static	int	reg[D_NONE];
 static	int	regrex[D_NONE+1];
 static	void	asmins(Link *ctxt, Prog *p);
@@ -2484,7 +2482,7 @@ asmando(Link *ctxt, Addr *a, int o)
 }
 
 static void
-bytereg(Addr *a, char *t)
+bytereg(Addr *a, uint8 *t)
 {
 	if(a->index == D_NONE && (a->type >= D_AX && a->type <= D_R15)) {
 		a->type = D_AL + (a->type-D_AX);
@@ -2688,7 +2686,7 @@ mediaop(Link *ctxt, Optab *o, int op, int osize, int z)
 			break;
 		}
 	default:
-		if(ctxt->andptr == ctxt->and || ctxt->andptr[-1] != Pm)
+		if(ctxt->andptr == ctxt->and || ctxt->and[ctxt->andptr - ctxt->and - 1] != Pm)
 			*ctxt->andptr++ = Pm;
 		break;
 	}
@@ -2904,8 +2902,13 @@ found:
 		asmando(ctxt, &p->to, o->op[z+1]);
 		break;
 
+	case Zcallindreg:
+		r = addrel(ctxt->cursym);
+		r->off = p->pc;
+		r->type = R_CALLIND;
+		r->siz = 0;
+		// fallthrough
 	case Zo_m64:
-	case_Zo_m64:
 		*ctxt->andptr++ = op;
 		asmandsz(ctxt, &p->to, o->op[z+1], 0, 1);
 		break;
@@ -3082,13 +3085,6 @@ found:
 		put4(ctxt, 0);
 		break;
 
-	case Zcallindreg:
-		r = addrel(ctxt->cursym);
-		r->off = p->pc;
-		r->type = R_CALLIND;
-		r->siz = 0;
-		goto case_Zo_m64;
-
 	case Zbr:
 	case Zjmp:
 	case Zloop:
@@ -3450,7 +3446,7 @@ nacltrunc(Link *ctxt, int reg)
 static void
 asmins(Link *ctxt, Prog *p)
 {
-	int n, np, c;
+	int i, n, np, c;
 	uchar *and0;
 	Reloc *r;
 	
@@ -3575,7 +3571,8 @@ asmins(Link *ctxt, Prog *p)
 		ctxt->andptr++;
 	}
 	n = ctxt->andptr - ctxt->and;
-	for(r=ctxt->cursym->r+ctxt->cursym->nr; r-- > ctxt->cursym->r; ) {
+	for(i=ctxt->cursym->nr-1; i>=0; i--) {
+		r = ctxt->cursym->r+i;
 		if(r->off < p->pc)
 			break;
 		if(ctxt->rexflag)

src/liblink/asm8.c

@@ -43,8 +43,6 @@ enum
 	FuncAlign = 16
 };
 
-extern char *anames6[];
-
 typedef	struct	Optab	Optab;
 
 struct	Optab
@@ -142,7 +140,7 @@ enum
 };
 
 static	uchar	ycover[Ymax*Ymax];
-static	char	reg[D_NONE];
+static	int	reg[D_NONE];
 static	void	asmins(Link *ctxt, Prog *p);
 
 static uchar	ynone[] =
@@ -1902,7 +1900,11 @@ bad:
 	return;
 }
 
-#define	E	0xff
+enum
+{
+	E = 0xff,
+};
+
 static uchar	ymovtab[] =
 {
 /* push */
@@ -2134,7 +2136,7 @@ mediaop(Link *ctxt, Optab *o, int op, int osize, int z)
 			break;
 		}
 	default:
-		if(ctxt->andptr == ctxt->and || ctxt->andptr[-1] != Pm)
+		if(ctxt->andptr == ctxt->and || ctxt->and[ctxt->andptr - ctxt->and - 1] != Pm)
 			*ctxt->andptr++ = Pm;
 		break;
 	}
@@ -2289,8 +2291,13 @@ found:
 		*ctxt->andptr++ = p->from.offset;
 		break;
 
+	case Zcallindreg:
+		r = addrel(ctxt->cursym);
+		r->off = p->pc;
+		r->type = R_CALLIND;
+		r->siz = 0;
+		// fallthrough
 	case Zo_m:
-	case_Zo_m:
 		*ctxt->andptr++ = op;
 		asmand(ctxt, &p->to, o->op[z+1]);
 		break;
@@ -2511,13 +2518,6 @@ found:
 		put4(ctxt, 0);
 		break;
 
-	case Zcallindreg:
-		r = addrel(ctxt->cursym);
-		r->off = p->pc;
-		r->type = R_CALLIND;
-		r->siz = 0;
-		goto case_Zo_m;
-
 	case Zbyte:
 		v = vaddr(ctxt, &p->from, &rel);
 		if(rel.siz != 0) {

src/liblink/list6.c

@@ -217,7 +217,7 @@ conv:
 	return fmtstrcpy(fp, str);
 }
 
-char*	regstr[] =
+static char*	regstr[] =
 {
 	"AL",	/* [D_AL] */
 	"CL",

src/liblink/list8.c

@@ -211,7 +211,7 @@ conv:
 	return fmtstrcpy(fp, str);
 }
 
-char*	regstr[] =
+static char*	regstr[] =
 {
 	"AL",	/* [D_AL] */
 	"CL",

src/liblink/obj5.c

@@ -707,28 +707,28 @@ softfloat(Link *ctxt, LSym *cursym)
 
 		default:
 			goto notsoft;
+		}
 
-		soft:
-			if (!wasfloat || (p->mark&LABEL)) {
-				next = ctxt->arch->prg();
-				*next = *p;
+	soft:
+		if (!wasfloat || (p->mark&LABEL)) {
+			next = ctxt->arch->prg();
+			*next = *p;
 
-				// BL _sfloat(SB)
-				*p = zprg;
-				p->link = next;
-				p->as = ABL;
+			// BL _sfloat(SB)
+			*p = zprg;
+			p->link = next;
+			p->as = ABL;
  				p->to.type = D_BRANCH;
-				p->to.sym = symsfloat;
-				p->lineno = next->lineno;
-
-				p = next;
-				wasfloat = 1;
-			}
-			break;
+			p->to.sym = symsfloat;
+			p->lineno = next->lineno;
 
-		notsoft:
-			wasfloat = 0;
+			p = next;
+			wasfloat = 1;
 		}
+		continue;
+
+	notsoft:
+		wasfloat = 0;
 	}
 }
 

src/liblink/sym.c

@@ -194,19 +194,14 @@ LSym*
 linknewsym(Link *ctxt, char *symb, int v)
 {
 	LSym *s;
-	int l;
 
-	l = strlen(symb) + 1;
 	s = malloc(sizeof(*s));
 	memset(s, 0, sizeof(*s));
 
 	s->dynid = -1;
 	s->plt = -1;
 	s->got = -1;
-	s->name = malloc(l + 1);
-	memmove(s->name, symb, l);
-	s->name[l] = '\0';
-
+	s->name = estrdup(symb);
 	s->type = 0;
 	s->version = v;
 	s->value = 0;