cmd/5a, cmd/5c, cmd/6a, cmd/6c, cmd/8a, cmd/8c, cmd/cc: support for Native Client

From the original description in CL 15770043

The main change here is to consult $GOARCH.

In 6c, when GOOS=nacl, some of the more complex addressing modes must be disabled, and the BP and R15 registers must not be used.

See golang.org/s/go13nacl for design overview.

LGTM=rsc
R=golang-codereviews, gobot, rsc
CC=golang-codereviews
https://golang.org/cl/69020044

src/cmd/5a/lex.c

@@ -73,6 +73,12 @@ main(int argc, char *argv[])
 	listinit5();
 	fmtinstall('L', Lconv);
 
+	// Allow GOARCH=thestring or GOARCH=thestringsuffix,
+	// but not other values.	
+	p = getgoarch();
+	if(strncmp(p, thestring, strlen(thestring)) != 0)
+		sysfatal("cannot use %cc with GOARCH=%s", thechar, p);
+
 	ensuresymb(NSYMB);
 	memset(debug, 0, sizeof(debug));
 	cinit();
@@ -162,7 +168,7 @@ assemble(char *file)
 		errorexit();
 	}
 	Binit(&obuf, of, OWRITE);
-	Bprint(&obuf, "go object %s %s %s\n", getgoos(), thestring, getgoversion());
+	Bprint(&obuf, "go object %s %s %s\n", getgoos(), getgoarch(), getgoversion());
 	Bprint(&obuf, "!\n");
 
 	for(pass = 1; pass <= 2; pass++) {

src/cmd/5c/swt.c

@@ -354,7 +354,7 @@ gextern(Sym *s, Node *a, int32 o, int32 w)
 void
 outcode(void)
 {
-	Bprint(&outbuf, "go object %s %s %s\n", getgoos(), thestring, getgoversion());
+	Bprint(&outbuf, "go object %s %s %s\n", getgoos(), getgoarch(), getgoversion());
 	if(pragcgobuf.to > pragcgobuf.start) {
 		Bprint(&outbuf, "\n");
 		Bprint(&outbuf, "$$  // exports\n\n");

src/cmd/5c/txt.c

@@ -33,13 +33,14 @@
 
 LinkArch	*thelinkarch = &linkarm;
 
+int thechar = '5';
+char *thestring = "arm";
+
 void
 ginit(void)
 {
 	Type *t;
 
-	thechar = '5';
-	thestring = "arm";
 	exregoffset = REGEXT;
 	exfregoffset = FREGEXT;
 	listinit();

src/cmd/6a/lex.c

@@ -79,6 +79,12 @@ main(int argc, char *argv[])
 	listinit6();
 	fmtinstall('L', Lconv);
 
+	// Allow GOARCH=thestring or GOARCH=thestringsuffix,
+	// but not other values.	
+	p = getgoarch();
+	if(strncmp(p, thestring, strlen(thestring)) != 0)
+		sysfatal("cannot use %cc with GOARCH=%s", thechar, p);
+
 	ensuresymb(NSYMB);
 	memset(debug, 0, sizeof(debug));
 	cinit();
@@ -164,7 +170,7 @@ assemble(char *file)
 		errorexit();
 	}
 	Binit(&obuf, of, OWRITE);
-	Bprint(&obuf, "go object %s %s %s\n", getgoos(), thestring, getgoversion());
+	Bprint(&obuf, "go object %s %s %s\n", getgoos(), getgoarch(), getgoversion());
 	Bprint(&obuf, "!\n");
 
 	for(pass = 1; pass <= 2; pass++) {

src/cmd/6c/reg.c

@@ -717,7 +717,7 @@ addmove(Reg *r, int bn, int rn, int f)
 		p1->as = AMOVB;
 	if(v->etype == TSHORT || v->etype == TUSHORT)
 		p1->as = AMOVW;
-	if(v->etype == TVLONG || v->etype == TUVLONG || v->etype == TIND)
+	if(v->etype == TVLONG || v->etype == TUVLONG || (v->etype == TIND && ewidth[TIND] == 8))
 		p1->as = AMOVQ;
 	if(v->etype == TFLOAT)
 		p1->as = AMOVSS;
@@ -1373,6 +1373,8 @@ BtoR(int32 b)
 {
 
 	b &= 0xffffL;
+	if(nacl)
+		b &= ~((1<<(D_BP-D_AX)) | (1<<(D_R15-D_AX)));
 	if(b == 0)
 		return 0;
 	return bitno(b) + D_AX;

src/cmd/6c/sgen.c

@@ -207,7 +207,7 @@ xcom(Node *n)
 				n->addable = 8;
 			break;
 		}
-		if(n->addable == 8 && !side(n)) {
+		if(n->addable == 8 && !side(n) && !nacl) {
 			indx(n);
 			l = new1(OINDEX, idx.basetree, idx.regtree);
 			l->scale = idx.scale;

src/cmd/6c/swt.c

@@ -228,7 +228,7 @@ outcode(void)
 	}
 	Binit(&b, f, OWRITE);
 
-	Bprint(&b, "go object %s %s %s\n", getgoos(), thestring, getgoversion());
+	Bprint(&b, "go object %s %s %s\n", getgoos(), getgoarch(), getgoversion());
 	if(pragcgobuf.to > pragcgobuf.start) {
 		Bprint(&b, "\n");
 		Bprint(&b, "$$  // exports\n\n");
@@ -292,6 +292,21 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		break;
 
 	case Aarg1:	/* initial align of parameter */
+		if(ewidth[TIND] == 4) {
+			if(typesu[t->etype]) {
+				for(v = t->link; v != T; v = v->down)
+					o = align(o, v, Aarg1, maxalign);
+				goto out;
+			}
+			w = ewidth[t->etype];
+			if(typev[t->etype] || t->etype == TDOUBLE)
+				w = 8;
+			else if(w <= 0 || w >= 4)
+				w = 4;
+			else
+				w = 1;
+			break;
+		}
 		w = ewidth[t->etype];
 		if(w <= 0 || w >= SZ_VLONG) {
 			w = SZ_VLONG;
@@ -302,6 +317,10 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 
 	case Aarg2:	/* width of a parameter */
 		o += t->width;
+		if(ewidth[TIND] == 4) {
+			o = align(o, t, Aarg1, maxalign);
+			goto out;
+		}
 		w = t->width;
 		if(w > SZ_VLONG)
 			w = SZ_VLONG;
@@ -315,6 +334,7 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 	o = xround(o, w);
 	if(maxalign && *maxalign < w)
 		*maxalign = w;
+out:
 	if(debug['A'])
 		print("align %s %d %T = %d\n", bnames[op], i, t, o);
 	return o;

src/cmd/6c/txt.c

@@ -32,15 +32,18 @@
 
 LinkArch	*thelinkarch = &linkamd64;
 
+int thechar = '6';
+char *thestring = "amd64";
+
 void
 ginit(void)
 {
 	int i;
 	Type *t;
 
-	thechar = '6';
+	dodefine("_64BITREG");
-	thestring = "amd64";
+	if(ewidth[TIND] == 8)
-	dodefine("_64BIT");
+		dodefine("_64BIT");
 	listinit();
 	nstring = 0;
 	mnstring = 0;
@@ -130,6 +133,10 @@ ginit(void)
 		if(i >= D_X0 && i <= D_X7)
 			reg[i] = 0;
 	}
+	if(nacl) {
+		reg[D_BP] = 1;
+		reg[D_R15] = 1;
+	}
 }
 
 void
@@ -139,6 +146,10 @@ gclean(void)
 	Sym *s;
 
 	reg[D_SP]--;
+	if(nacl) {
+		reg[D_BP]--;
+		reg[D_R15]--;
+	}
 	for(i=D_AX; i<=D_R15; i++)
 		if(reg[i])
 			diag(Z, "reg %R left allocated", i);
@@ -569,7 +580,7 @@ naddr(Node *n, Addr *a)
 		}
 		a->sym = nil;
 		a->type = D_CONST;
-		if(typev[n->type->etype] || n->type->etype == TIND)
+		if(typev[n->type->etype] || (n->type->etype == TIND && ewidth[TIND] == 8))
 			a->offset = n->vconst;
 		else
 			a->offset = convvtox(n->vconst, typeu[n->type->etype]? TULONG: TLONG);
@@ -632,6 +643,12 @@ gmove(Node *f, Node *t)
 
 	ft = f->type->etype;
 	tt = t->type->etype;
+	if(ewidth[TIND] == 4) {
+		if(ft == TIND)
+			ft = TUINT;
+		if(tt == TIND)
+			tt = TUINT;
+	}
 	t64 = tt == TVLONG || tt == TUVLONG || tt == TIND;
 	if(debug['M'])
 		print("gop: %O %O[%s],%O[%s]\n", OAS,
@@ -723,6 +740,8 @@ gmove(Node *f, Node *t)
 		goto ld;
 	case TIND:
 		a = AMOVQ;
+		if(ewidth[TIND] == 4)
+			a = AMOVL;
 
 	ld:
 		regalloc(&nod, f, t);
@@ -1228,6 +1247,8 @@ gopcode(int o, Type *ty, Node *f, Node *t)
 	et = TLONG;
 	if(ty != T)
 		et = ty->etype;
+	if(et == TIND && ewidth[TIND] == 4)
+		et = TUINT;
 	if(debug['M']) {
 		if(f != Z && f->type != T)
 			print("gop: %O %O[%s],", o, f->op, tnames[et]);
@@ -1564,7 +1585,7 @@ exreg(Type *t)
 		if(exregoffset >= 64)
 			return 0;
 		o = exregoffset;
-		exregoffset += 8;
+		exregoffset += ewidth[TIND];
 		return o+1;	// +1 to avoid 0 == failure; naddr's case OEXREG will subtract 1.
 	}
 	return 0;

src/cmd/8a/lex.c

@@ -79,6 +79,12 @@ main(int argc, char *argv[])
 	listinit8();
 	fmtinstall('L', Lconv);
 
+	// Allow GOARCH=thestring or GOARCH=thestringsuffix,
+	// but not other values.	
+	p = getgoarch();
+	if(strncmp(p, thestring, strlen(thestring)) != 0)
+		sysfatal("cannot use %cc with GOARCH=%s", thechar, p);
+
 	ensuresymb(NSYMB);
 	memset(debug, 0, sizeof(debug));
 	cinit();
@@ -163,7 +169,7 @@ assemble(char *file)
 		errorexit();
 	}
 	Binit(&obuf, of, OWRITE);
-	Bprint(&obuf, "go object %s %s %s\n", getgoos(), thestring, getgoversion());
+	Bprint(&obuf, "go object %s %s %s\n", getgoos(), getgoarch(), getgoversion());
 	Bprint(&obuf, "!\n");
 
 	for(pass = 1; pass <= 2; pass++) {

src/cmd/8c/swt.c

@@ -233,7 +233,7 @@ outcode(void)
 	}
 	Binit(&b, f, OWRITE);
 
-	Bprint(&b, "go object %s %s %s\n", getgoos(), thestring, getgoversion());
+	Bprint(&b, "go object %s %s %s\n", getgoos(), getgoarch(), getgoversion());
 	if(pragcgobuf.to > pragcgobuf.start) {
 		Bprint(&b, "\n");
 		Bprint(&b, "$$  // exports\n\n");

src/cmd/8c/txt.c

@@ -32,14 +32,15 @@
 
 LinkArch	*thelinkarch = &link386;
 
+int thechar = '8';
+char *thestring = "386";
+
 void
 ginit(void)
 {
 	int i;
 	Type *t;
 
-	thechar = '8';
-	thestring = "386";
 	exregoffset = 0;
 	exfregoffset = 0;
 	listinit();

src/cmd/cc/cc.h

@@ -506,8 +506,8 @@ EXTERN	Sym*	symstring;
 EXTERN	int	taggen;
 EXTERN	Type*	tfield;
 EXTERN	Type*	tufield;
-EXTERN	int	thechar;
+extern	int	thechar;
-EXTERN	char*	thestring;
+extern	char*	thestring;
 extern	LinkArch*	thelinkarch;
 EXTERN	Type*	thisfn;
 EXTERN	int32	thunk;
@@ -524,6 +524,7 @@ EXTERN	int	flag_largemodel;
 EXTERN	int	ncontin;
 EXTERN	int	canreach;
 EXTERN	int	warnreach;
+EXTERN	int	nacl;
 EXTERN	Bits	zbits;
 EXTERN	Fmt	pragcgobuf;
 EXTERN	Biobuf	bstdout;

src/cmd/cc/lex.c

@@ -117,6 +117,19 @@ void
 main(int argc, char *argv[])
 {
 	int c;
+	char *p;
+
+	// Allow GOARCH=thestring or GOARCH=thestringsuffix,
+	// but not other values.	
+	p = getgoarch();
+	if(strncmp(p, thestring, strlen(thestring)) != 0)
+		sysfatal("cannot use %cc with GOARCH=%s", thechar, p);
+	if(strcmp(getgoarch(), "amd64p32") == 0) // must be before cinit
+		ewidth[TIND] = 4;
+		
+	nacl = strcmp(getgoos(), "nacl") == 0;
+	if(nacl)
+		flag_largemodel = 1;
 
 	quotefmtinstall(); // before cinit, which overrides %Q