make Syms smaller.

collapse a lot of duplication in dcl.c
switch to NodeList* from Dcl*

R=ken
OCL=32770
CL=32770

14 files changed, 210 insertions, 418 deletions

diff --git a/src/cmd/5g/ggen.c b/src/cmd/5g/ggen.c
index 04fe16ce1..337f5f8a0 100644
--- a/src/cmd/5g/ggen.c
+++ b/src/cmd/5g/ggen.c
@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-
 #undef	EXTERN
 #define	EXTERN
 #include "gg.h"
@@ -59,7 +58,6 @@ compile(Node *fn)
 
 	pl = newplist();
 	pl->name = curfn->nname;
-	pl->locals = autodcl;
 
 	nodconst(&nod1, types[TINT32], 0);
 	ptxt = gins(ATEXT, curfn->nname, &nod1);
diff --git a/src/cmd/6g/ggen.c b/src/cmd/6g/ggen.c
index 63dbd6835..64220bc84 100644
--- a/src/cmd/6g/ggen.c
+++ b/src/cmd/6g/ggen.c
@@ -59,7 +59,6 @@ compile(Node *fn)
 
 	pl = newplist();
 	pl->name = curfn->nname;
-	pl->locals = autodcl;
 
 	nodconst(&nod1, types[TINT32], 0);
 	ptxt = gins(ATEXT, curfn->nname, &nod1);
@@ -573,7 +572,7 @@ cgen_div(int op, Node *nl, Node *nr, Node *res)
 
 	regfree(&ax);
 	regfree(&dx);
-	
+
 	if(oldax.op != 0) {
 		gmove(&oldax, &ax);
 		regfree(&oldax);
@@ -582,7 +581,7 @@ cgen_div(int op, Node *nl, Node *nr, Node *res)
 		gmove(&olddx, &dx);
 		regfree(&olddx);
 	}
-		
+
 }
 
 /*
diff --git a/src/cmd/8g/ggen.c b/src/cmd/8g/ggen.c
index ee26a6110..3542ae690 100644
--- a/src/cmd/8g/ggen.c
+++ b/src/cmd/8g/ggen.c
@@ -57,7 +57,6 @@ compile(Node *fn)
 
 	pl = newplist();
 	pl->name = curfn->nname;
-	pl->locals = autodcl;
 
 	nodconst(&nod1, types[TINT32], 0);
 	ptxt = gins(ATEXT, curfn->nname, &nod1);
diff --git a/src/cmd/8g/gobj.c b/src/cmd/8g/gobj.c
index 683c77d40..fac2656ef 100644
--- a/src/cmd/8g/gobj.c
+++ b/src/cmd/8g/gobj.c
@@ -358,9 +358,9 @@ datastring(char *s, int len, Addr *a)
 	*a = ao;
 
 	// only generate data the first time.
-	if(ao.sym->uniq)
+	if(ao.sym->flags & SymUniq)
 		return;
-	ao.sym->uniq = 1;
+	ao.sym->flags |= SymUniq;
 
 	data();
 	for(w=0; w<len; w+=8) {
@@ -438,9 +438,9 @@ datagostring(Strlit *sval, Addr *a)
 	}
 
 	*a = ao;
-	if(ao.sym->uniq)
+	if(ao.sym->flags & SymUniq)
 		return;
-	ao.sym->uniq = 1;
+	ao.sym->flags |= SymUniq;
 
 	data();
 	// DATA gostring, wp, $cstring
diff --git a/src/cmd/gc/dcl.c b/src/cmd/gc/dcl.c
index 7003045be..8849709ed 100644
--- a/src/cmd/gc/dcl.c
+++ b/src/cmd/gc/dcl.c
@@ -25,14 +25,11 @@ static	Sym*	dclstack;
 void
 dcopy(Sym *a, Sym *b)
 {
+	a->package = b->package;
 	a->name = b->name;
 	a->def = b->def;
-	a->package = b->package;
-	a->undef = b->undef;
-	a->vargen = b->vargen;
 	a->block = b->block;
 	a->lastlineno = b->lastlineno;
-	a->offset = b->offset;
 }
 
 Sym*
@@ -148,155 +145,79 @@ testdclstack(void)
 /*
  * declare individual names - var, typ, const
  */
-static void
-redeclare(char *str, Sym *s)
-{
-	if(s->block == block) {
-		yyerror("%s %S redeclared in this block", str, s);
-		print("	previous declaration at %L\n", s->lastlineno);
-	}
-	s->block = block;
-	s->lastlineno = lineno;
-}
-
 void
-addvar(Node *n, Type *t, int ctxt)
+declare(Node *n, int ctxt)
 {
-	Dcl *r, *d;
 	Sym *s;
+	char *what;
 	int gen;
-
-	if(n==N || n->sym == S || (n->op != ONAME && n->op != ONONAME) || t == T)
-		fatal("addvar: n=%N t=%T nil", n, t);
+	static int typegen, vargen;
 
 	s = n->sym;
-
-	if(ctxt == PEXTERN || ctxt == PFUNC) {
-		r = externdcl;
-		gen = 0;
+	gen = 0;
+	if(ctxt == PEXTERN) {
+		externdcl = list(externdcl, n);
 	} else {
-		r = autodcl;
-		vargen++;
-		gen = vargen;
+		if(autodcl != nil)
+			autodcl = list(autodcl, n);
+		if(n->op == OTYPE)
+			gen = ++typegen;
+		else if(n->op == ONAME)
+			gen = ++vargen;
 		pushdcl(s);
 	}
 
-	redeclare("variable", s);
-	n->op = ONAME;
-	s->vargen = gen;
-	s->def = n;
-	s->offset = 0;
+	if(s->block == block) {
+		what = "???";
+		switch(n->op) {
+		case ONAME:
+			what = "variable";
+			break;
+		case OLITERAL:
+			what = "constant";
+			break;
+		case OTYPE:
+			what = "type";
+			break;
+		}
 
-	n->funcdepth = funcdepth;
-	n->type = t;
+		yyerror("%s %S redeclared in this block", what, s);
+		print("\tprevious declaration at %L\n", s->lastlineno);
+	}
+	s->block = block;
+	s->lastlineno = lineno;
+	s->def = n;
 	n->vargen = gen;
+	n->funcdepth = funcdepth;
 	n->class = ctxt;
 
-	d = dcl();
-	d->dsym = s;
-	d->dnode = n;
-	d->op = ONAME;
-
-	r->back->forw = d;
-	r->back = d;
-
-	if(dflag()) {
-		if(ctxt == PEXTERN)
-			print("extern var-dcl %S G%ld %T\n", s, s->vargen, t);
-		else if(ctxt == PFUNC)
-			print("extern func-dcl %S G%ld %T\n", s, s->vargen, t);
-		else
-			print("auto   var-dcl %S G%ld %T\n", s, s->vargen, t);
-	}
+	autoexport(n, ctxt);
 }
 
 void
-addtyp(Type *n, int ctxt)
+addvar(Node *n, Type *t, int ctxt)
 {
-	Dcl *r, *d;
-	Sym *s;
-	static int typgen;
-
-	if(n==T || n->sym == S)
-		fatal("addtyp: n=%T t=%T nil", n);
-
-	s = n->sym;
-
-	if(ctxt == PEXTERN)
-		r = externdcl;
-	else {
-		r = autodcl;
-		pushdcl(s);
-		n->vargen = ++typgen;
-	}
-
-	redeclare("type", s);
-	s->def = typenod(n);
-
-	d = dcl();
-	d->dsym = s;
-	d->dtype = n;
-	d->op = OTYPE;
-
-	d->back = r->back;
-	r->back->forw = d;
-	r->back = d;
-
-	d = dcl();
-	d->dtype = n;
-	d->op = OTYPE;
-
-	r = typelist;
-	d->back = r->back;
-	r->back->forw = d;
-	r->back = d;
+	if(n==N || n->sym == S || (n->op != ONAME && n->op != ONONAME) || t == T)
+		fatal("addvar: n=%N t=%T nil", n, t);
 
-	if(dflag()) {
-		if(ctxt == PEXTERN)
-			print("extern typ-dcl %S G%ld %T\n", s, s->vargen, n);
-		else
-			print("auto   typ-dcl %S G%ld %T\n", s, s->vargen, n);
-	}
+	n->op = ONAME;
+	declare(n, ctxt);
+	n->type = t;
 }
 
-// TODO(rsc): cut
 void
-addconst(Node *n, Node *e, int ctxt)
+addtyp(Type *n, int ctxt)
 {
-	Sym *s;
-	Dcl *r, *d;
-
-	if(n->op != ONAME && n->op != ONONAME)
-		fatal("addconst: not a name");
-
-	if(e->op != OLITERAL) {
-		yyerror("expression must be a constant");
-		return;
-	}
-
-	s = n->sym;
+	Node *def;
 
-	if(ctxt == PEXTERN)
-		r = externdcl;
-	else {
-		r = autodcl;
-		pushdcl(s);
-	}
-
-	redeclare("constant", s);
-	s->def = e;
-	e->sym = s;
+	if(n==T || n->sym == S)
+		fatal("addtyp: n=%T t=%T nil", n);
 
-	d = dcl();
-	d->dsym = s;
-	d->dnode = e;
-	d->op = OLITERAL;
-	d->back = r->back;
-	r->back->forw = d;
-	r->back = d;
+	def = typenod(n);
+	declare(def, ctxt);
+	n->vargen = def->vargen;
 
-	if(dflag())
-		print("const-dcl %S %N\n", n->sym, n->sym->def);
+	typelist = list(typelist, def);
 }
 
 /*
@@ -320,21 +241,10 @@ dodclvar(Node *n, Type *t, NodeList **init)
 		t = typ(TFORW);
 
 	addvar(n, t, dclcontext);
-	autoexport(n->sym);
 	if(funcdepth > 0)
 		*init = list(*init, nod(ODCL, n, N));
 }
 
-// TODO(rsc): cut
-void
-dodclconst(Node *n, Node *e)
-{
-	if(n == N)
-		return;
-	addconst(n, e, dclcontext);
-	autoexport(n->sym);
-}
-
 /*
  * introduce a type named n
  * but it is an unknown type for now
@@ -354,15 +264,7 @@ dodcltype(Type *n)
 			n = s->def->type;
 			if(s->block != block) {
 				// completing forward struct from other file
-				Dcl *d, *r;
-				d = dcl();
-				d->dsym = s;
-				d->dtype = n;
-				d->op = OTYPE;
-				r = externdcl;
-				d->back = r->back;
-				r->back->forw = d;
-				r->back = d;
+				externdcl = list(externdcl, typenod(n));
 			}
 			goto found;
 		}
@@ -373,7 +275,7 @@ dodcltype(Type *n)
 
 found:
 	n->local = 1;
-	autoexport(n->sym);
+	autoexport(typenod(n), dclcontext);
 	return n;
 }
 
@@ -458,11 +360,10 @@ updatetype(Type *n, Type *t)
 NodeList*
 variter(NodeList *vl, Node *t, NodeList *el)
 {
-	int doexpr, gen;
+	int doexpr;
 	Node *v, *e;
 	NodeList *init;
 	Sym *s;
-	Dcl *r, *d;
 
 	init = nil;
 	doexpr = el != nil;
@@ -477,28 +378,13 @@ variter(NodeList *vl, Node *t, NodeList *el)
 		} else
 			e = N;
 
-		v = vl->n;		
+		v = vl->n;
 		s = v->sym;
-		if(dclcontext == PEXTERN || dclcontext == PFUNC) {
-			r = externdcl;
-			gen = 0;
-		} else {
-			r = autodcl;
-			gen = ++vargen;
-			pushdcl(s);
-		}
-			
-		redeclare("variable", s);
-		s->def = v;
-		// TODO: vargen
-		s->offset = 0;
-		s->block = block;
 
 		v->op = ONAME;
-		v->class = dclcontext;
+		declare(v, dclcontext);
 		v->ntype = t;
-		v->funcdepth = funcdepth;
-		v->vargen = gen;
+
 		if(e != N || funcdepth > 0) {
 			if(funcdepth > 0)
 				init = list(init, nod(ODCL, v, N));
@@ -507,15 +393,6 @@ variter(NodeList *vl, Node *t, NodeList *el)
 			if(e->right != N)
 				v->defn = e;
 		}
-		
-		d = dcl();
-		d->dsym = s;
-		d->dnode = v;
-		d->op = ONAME;
-		r->back->forw = d;
-		r->back = d;
-
-		autoexport(s);
 	}
 	if(el != nil)
 		yyerror("extra expr in var dcl");
@@ -531,7 +408,6 @@ constiter(NodeList *vl, Node *t, NodeList *cl)
 {
 	Node *v, *c;
 	NodeList *vv;
-	Sym *s;
 
 	vv = vl;
 	if(cl == nil) {
@@ -554,16 +430,11 @@ constiter(NodeList *vl, Node *t, NodeList *cl)
 		cl = cl->next;
 
 		v = vl->n;
-		s = v->sym;
-		if(dclcontext != PEXTERN)
-			pushdcl(s);
-		redeclare("constant", s);
-		s->def = v;
-
 		v->op = OLITERAL;
+		declare(v, dclcontext);
+
 		v->ntype = t;
 		v->defn = c;
-		autoexport(s);
 	}
 	if(cl != nil)
 		yyerror("extra expr in const dcl");
@@ -572,10 +443,8 @@ constiter(NodeList *vl, Node *t, NodeList *cl)
 }
 
 /*
- * this generates a new name that is
- * pushed down on the declaration list.
- * no diagnostics are produced as this
- * name will soon be declared.
+ * this generates a new name node,
+ * typically for labels or other one-off names.
  */
 Node*
 newname(Sym *s)
@@ -591,6 +460,11 @@ newname(Sym *s)
 	return n;
 }
 
+/*
+ * this generates a new name node for a name
+ * being declared.  if at the top level, it might return
+ * an ONONAME node created by an earlier reference.
+ */
 Node*
 dclname(Sym *s)
 {
@@ -685,42 +559,18 @@ newtype(Sym *s)
 	return t;
 }
 
-Type*
-oldtype(Sym *s)
-{
-	Type *t;
-
-	if(s == S)
-		return T;
-	if(s->def == N || s->def->op != OTYPE) {
-		if(!s->undef)
-			yyerror("%S is not a type", s);
-		return T;
-	}
-	t = s->def->type;
-
-	/*
-	 * If t is lowercase and not in our package
-	 * and this isn't a reference during the parsing
-	 * of import data, complain.
-	 */
-	if(pkgimportname == S && !exportname(s->name) && strcmp(s->package, package) != 0)
-		yyerror("cannot use type %T", t);
-	return t;
-}
-
 /*
  * type check top level declarations
  */
 void
 dclchecks(void)
 {
-	Dcl *d;
-	
-	for(d=externdcl; d!=D; d=d->forw) {
-		if(d->op != ONAME)
+	NodeList *l;
+
+	for(l=externdcl; l; l=l->next) {
+		if(l->n->op != ONAME)
 			continue;
-		typecheck(&d->dnode, Erv);
+		typecheck(&l->n, Erv);
 	}
 }
 
@@ -1228,8 +1078,7 @@ funchdr(Node *n)
 	}
 
 	// change the declaration context from extern to auto
-	autodcl = dcl();
-	autodcl->back = autodcl;
+	autodcl = list1(nod(OXXX, N, N));
 
 	if(funcdepth == 0 && dclcontext != PEXTERN)
 		fatal("funchdr: dclcontext");
@@ -1312,8 +1161,7 @@ funclit0(Node *t)
 	funclit = n;
 
 	// new declaration context
-	autodcl = dcl();
-	autodcl->back = autodcl;
+	autodcl = list1(nod(OEMPTY, N, N));
 
 	typecheck(&t, Etype);
 	funcargs(t->type);
@@ -1330,6 +1178,7 @@ funclit1(Node *ntype, NodeList *body)
 	Iter save;
 	int narg, shift;
 	NodeList *args, *l, *in, *out;
+	static int closgen;
 
 	type = ntype->type;
 	popdcl();
@@ -1408,8 +1257,7 @@ funclit1(Node *ntype, NodeList *body)
 	ft->outnamed = type->outnamed;
 
 	// declare function.
-	vargen++;
-	snprint(namebuf, sizeof(namebuf), "_f%.3ld·%s", vargen, filename);
+	snprint(namebuf, sizeof(namebuf), "_f%.3ld·%s", ++closgen, filename);
 	f = newname(lookup(namebuf));
 	addvar(f, ft, PFUNC);
 	f->funcdepth = 0;
diff --git a/src/cmd/gc/export.c b/src/cmd/gc/export.c
index 74df55363..112dd2711 100644
--- a/src/cmd/gc/export.c
+++ b/src/cmd/gc/export.c
@@ -8,49 +8,39 @@
 void dumpsym(Sym*);
 
 void
-addexportsym(Sym *s)
+addexportsym(Node *n)
 {
-	Dcl *d, *r;
-
-	d = mal(sizeof(*d));
-	d->dsym = s;
-	d->dnode = N;
-	d->lineno = lineno;
-
-	r = exportlist;
-	d->back = r->back;
-	r->back->forw = d;
-	r->back = d;
+	exportlist = list(exportlist, n);
 }
 
 void
-exportsym(Sym *s)
+exportsym(Node *n)
 {
-	if(s == S)
+	if(n == N || n->sym == S)
 		return;
-	if(s->export != 0) {
-		if(s->export != 1)
-			yyerror("export/package mismatch: %S", s);
+	if(n->sym->flags & (SymExport|SymPackage)) {
+		if(n->sym->flags & SymPackage)
+			yyerror("export/package mismatch: %S", n->sym);
 		return;
 	}
-	s->export = 1;
+	n->sym->flags |= SymExport;
 
-	addexportsym(s);
+	addexportsym(n);
 }
 
 void
-packagesym(Sym *s)
+packagesym(Node *n)
 {
-	if(s == S)
+	if(n == N || n->sym == S)
 		return;
-	if(s->export != 0) {
-		if(s->export != 2)
-			yyerror("export/package mismatch: %S", s);
+	if(n->sym->flags & (SymExport|SymPackage)) {
+		if(n->sym->flags & SymExport)
+			yyerror("export/package mismatch: %S", n->sym);
 		return;
 	}
-	s->export = 2;
+	n->sym->flags |= SymPackage;
 
-	addexportsym(s);
+	addexportsym(n);
 }
 
 int
@@ -65,17 +55,16 @@ exportname(char *s)
 }
 
 void
-autoexport(Sym *s)
+autoexport(Node *n, int ctxt)
 {
-	if(s == S)
+	if(n == N || n->sym == S)
 		return;
-	if(dclcontext != PEXTERN)
+	if((ctxt != PEXTERN && ctxt != PFUNC) || dclcontext != PEXTERN)
 		return;
-	if(exportname(s->name)) {
-		exportsym(s);
-	} else {
-		packagesym(s);
-	}
+	if(exportname(n->sym->name) || strcmp(n->sym->name, "init") == 0)
+		exportsym(n);
+	else
+		packagesym(n);
 }
 
 void
@@ -187,9 +176,9 @@ dumpsym(Sym *s)
 {
 	Type *f, *t;
 
-	if(s->exported != 0)
+	if(s->flags & SymExported)
 		return;
-	s->exported = 1;
+	s->flags |= SymExported;
 
 	if(s->def == N) {
 		yyerror("unknown export symbol: %S", s);
@@ -236,7 +225,7 @@ dumptype(Type *t)
 void
 dumpexport(void)
 {
-	Dcl *d;
+	NodeList *l;
 	int32 lno;
 
 	lno = lineno;
@@ -246,16 +235,16 @@ dumpexport(void)
 
 	Bprint(bout, "    package %s\n", package);
 
-	for(d=exportlist->forw; d!=D; d=d->forw) {
-		lineno = d->lineno;
-		dumpsym(d->dsym);
+	for(l=exportlist; l; l=l->next) {
+		lineno = l->n->lineno;
+		dumpsym(l->n->sym);
 	}
 
 	Bprint(bout, "\n$$  // local types\n");
 
-	for(d=typelist->forw; d!=D; d=d->forw) {
-		lineno = d->lineno;
-		dumptype(d->dtype);
+	for(l=typelist; l; l=l->next) {
+		lineno = l->n->lineno;
+		dumptype(l->n->type);
 	}
 
 	Bprint(bout, "\n$$\n");
@@ -286,10 +275,10 @@ importsym(Sym *s, int op)
 	// mark the symbol so it is not reexported
 	if(s->def == N) {
 		if(exportname(s->name))
-			s->export = 1;
+			s->flags |= SymExport;
 		else
-			s->export = 2;	// package scope
-		s->imported = 1;
+			s->flags |= SymPackage;	// package scope
+		s->flags |= SymImported;
 	}
 	return s;
 }
@@ -332,7 +321,12 @@ importconst(Sym *s, Type *t, Node *n)
 		return;
 	}
 
-	dodclconst(newname(s), n);
+	if(n->op != OLITERAL) {
+		yyerror("expression must be a constant");
+		return;
+	}
+	n->sym = s;
+	declare(n, PEXTERN);
 
 	if(debug['E'])
 		print("import const %S\n", s);
@@ -341,6 +335,8 @@ importconst(Sym *s, Type *t, Node *n)
 void
 importvar(Sym *s, Type *t, int ctxt)
 {
+	Node *n;
+
 	if(!exportname(s->name) && !mypackage(s))
 		return;
 
@@ -352,7 +348,9 @@ importvar(Sym *s, Type *t, int ctxt)
 			s, s->def->type, t);
 	}
 	checkwidth(t);
-	addvar(newname(s), t, ctxt);
+	n = newname(s);
+	n->type = t;
+	declare(n, ctxt);
 
 	if(debug['E'])
 		print("import var %S %lT\n", s, t);
@@ -393,8 +391,8 @@ importtype(Sym *s, Type *t)
 	case TFORWINTER:
 	case TFORWSTRUCT:
 		// allow re-export in case it gets defined
-		s->export = 0;
-		s->imported = 0;
+		s->flags &= ~(SymExport|SymPackage);
+		s->flags &= ~SymImported;
 		break;
 	default:
 		checkwidth(n->type);
diff --git a/src/cmd/gc/gen.c b/src/cmd/gc/gen.c
index 5fab59cdf..9872c5773 100644
--- a/src/cmd/gc/gen.c
+++ b/src/cmd/gc/gen.c
@@ -22,7 +22,7 @@ sysfunc(char *name)
 void
 allocparams(void)
 {
-	Dcl *d;
+	NodeList *l;
 	Node *n;
 	uint32 w;
 
@@ -31,14 +31,10 @@ allocparams(void)
 	 * slots for all automatics.
 	 * allocated starting at -w down.
 	 */
-	for(d=autodcl; d!=D; d=d->forw) {
-		if(d->op != ONAME)
+	for(l=autodcl; l; l=l->next) {
+		n = l->n;
+		if(n->op != ONAME || n->class != PAUTO)
 			continue;
-
-		n = d->dnode;
-		if(n->class != PAUTO)
-			continue;
-
 		typecheck(&n, Erv);
 		dowidth(n->type);
 		w = n->type->width;
diff --git a/src/cmd/gc/go.h b/src/cmd/gc/go.h
index 8a79a1abd..c403048cf 100644
--- a/src/cmd/gc/go.h
+++ b/src/cmd/gc/go.h
@@ -131,7 +131,6 @@ typedef	struct	Sym	Sym;
 typedef	struct	Node	Node;
 typedef	struct	NodeList	NodeList;
 typedef	struct	Type	Type;
-typedef	struct	Dcl	Dcl;
 
 struct	Type
 {
@@ -221,7 +220,7 @@ struct	Node
 	NodeList*	enter;
 	NodeList*	exit;
 	NodeList*	cvars;	// closure params
-	Dcl*	dcl;	// outer autodcl
+	NodeList*	dcl;	// outer autodcl
 
 	// OLITERAL/OREGISTER
 	Val	val;
@@ -258,44 +257,32 @@ struct NodeList
 	NodeList*	end;
 };
 
-struct	Sym
+enum
 {
-	ushort	block;		// blocknumber to catch redeclaration
+	SymExport	= 1<<0,
+	SymPackage	= 1<<1,
+	SymExported	= 1<<2,
+	SymImported	= 1<<3,
+	SymUniq		= 1<<4,
+	SymSiggen	= 1<<5,
+};
 
-	uchar	undef;		// a diagnostic has been generated
-	uchar	export;		// marked as export
-	uchar	exported;	// exported
-	uchar	imported;	// imported
+struct	Sym
+{
+	ushort	lexical;
+	uchar	flags;
 	uchar	sym;		// huffman encoding in object file
-	uchar	uniq;		// imbedded field name first found
-	uchar	siggen;		// signature generated
+	Sym*	link;
 
+	// saved and restored by dcopy
 	char*	package;	// package name
 	char*	name;		// variable name
 	Node*	def;		// definition: ONAME OTYPE OPACK or OLITERAL
-	vlong	offset;		// stack location if automatic
-	int32	lexical;
-	int32	vargen;		// unique variable number
+	int32	block;		// blocknumber to catch redeclaration
 	int32	lastlineno;	// last declaration for diagnostic
-	Sym*	link;
 };
 #define	S	((Sym*)0)
 
-struct	Dcl
-{
-	uchar	op;
-	ushort	block;
-	int32	lineno;
-
-	Sym*	dsym;		// for printing only
-	Node*	dnode;		// oname
-	Type*	dtype;		// otype
-
-	Dcl*	forw;
-	Dcl*	back;		// sentinel has pointer to last
-};
-#define	D	((Dcl*)0)
-
 typedef	struct	Iter	Iter;
 struct	Iter
 {
@@ -636,14 +623,11 @@ EXTERN	Mpint*	maxintval[NTYPE];
 EXTERN	Mpflt*	minfltval[NTYPE];
 EXTERN	Mpflt*	maxfltval[NTYPE];
 
-EXTERN	Dcl*	autodcl;
-EXTERN	Dcl*	paramdcl;
-EXTERN	Dcl*	externdcl;
-EXTERN	Dcl*	exportlist;
-EXTERN	Dcl*	signatlist;
-EXTERN	Dcl*	typelist;
+EXTERN	NodeList*	autodcl;
+EXTERN	NodeList*	externdcl;
+EXTERN	NodeList*	exportlist;
+EXTERN	NodeList*	typelist;
 EXTERN	int	dclcontext;		// PEXTERN/PAUTO
-EXTERN	int	importflag;
 EXTERN	int	inimportsys;
 EXTERN	int	initflag;		// compiling the init fn
 EXTERN	int	statuniqgen;		// name generator for static temps
@@ -652,13 +636,11 @@ EXTERN	int	loophack;
 EXTERN	uint32	iota;
 EXTERN	NodeList*	lastconst;
 EXTERN	Node*	lasttype;
-EXTERN	int32	vargen;
-EXTERN	int32	exportgen;
 EXTERN	int32	maxarg;
 EXTERN	int32	stksize;		// stack size for current frame
 EXTERN	int32	initstksize;		// stack size for init function
-EXTERN	ushort	blockgen;		// max block number
-EXTERN	ushort	block;			// current block number
+EXTERN	int32	blockgen;		// max block number
+EXTERN	int32	block;			// current block number
 EXTERN	int	hasdefer;		// flag that curfn has defer statetment
 
 EXTERN	Node*	curfn;
@@ -666,8 +648,6 @@ EXTERN	Node*	curfn;
 EXTERN	int	maxround;
 EXTERN	int	widthptr;
 
-EXTERN	Node*	retnil;
-
 EXTERN	Node*	typeswvar;
 
 EXTERN	char*	structpkg;
@@ -788,7 +768,6 @@ int32	setlineno(Node*);
 Node*	nod(int, Node*, Node*);
 Node*	nodlit(Val);
 Type*	typ(int);
-Dcl*	dcl(void);
 int	algtype(Type*);
 void	dodump(Node*, int);
 void	dump(char*, Node*);
@@ -878,10 +857,10 @@ int	simsimtype(Type*);
 /*
  *	dcl.c
  */
+void	declare(Node*, int);
 void	dodclvar(Node*, Type*, NodeList**);
 Type*	dodcltype(Type*);
 void	updatetype(Type*, Type*);
-void	dodclconst(Node*, Node*);
 void	defaultlit(Node**, Type*);
 void	defaultlit2(Node**, Node**, int);
 int	structcount(Type*);
@@ -941,10 +920,10 @@ NodeList*	initfix(NodeList*);
  *	export.c
  */
 void	renameimports(void);
-void	autoexport(Sym*);
+void	autoexport(Node*, int);
 int	exportname(char*);
-void	exportsym(Sym*);
-void	packagesym(Sym*);
+void	exportsym(Node*);
+void	packagesym(Node*);
 void	dumpe(Sym*);
 void	dumpexport(void);
 void	dumpexporttype(Sym*);
@@ -1065,7 +1044,6 @@ typedef	struct	Plist	Plist;
 struct	Plist
 {
 	Node*	name;
-	Dcl*	locals;
 	Prog*	firstpc;
 	int	recur;
 	Plist*	link;
diff --git a/src/cmd/gc/go.y b/src/cmd/gc/go.y
index 728645318..edb7c676e 100644
--- a/src/cmd/gc/go.y
+++ b/src/cmd/gc/go.y
@@ -274,7 +274,7 @@ xdcl:
 |	xfndcl
 	{
 		if($1 != N && $1->nname != N && $1->type->thistuple == 0)
-			autoexport($1->nname->sym);
+			autoexport($1->nname, dclcontext);
 		$$ = nil;
 	}
 |	';'
@@ -1643,7 +1643,12 @@ hidden_type1:
 	}
 |	LNAME
 	{
-		$$ = oldtype($1);
+		// predefined name like uint8
+		if($1->def == N || $1->def->op != OTYPE) {
+			yyerror("%S is not a type", $1);
+			$$ = T;
+		} else
+			$$ = $1->def->type;
 	}
 |	'[' ']' hidden_type
 	{
diff --git a/src/cmd/gc/init.c b/src/cmd/gc/init.c
index 5fc7f8bbc..445fa0d54 100644
--- a/src/cmd/gc/init.c
+++ b/src/cmd/gc/init.c
@@ -178,7 +178,7 @@ fninit(NodeList *n)
 	a = nod(ORETURN, N, N);
 	r = list(r, a);
 
-	exportsym(fn->nname->sym);
+	exportsym(fn->nname);
 
 	fn->nbody = r;
 //dump("b", fn);
diff --git a/src/cmd/gc/lex.c b/src/cmd/gc/lex.c
index f79814112..3a8cba41b 100644
--- a/src/cmd/gc/lex.c
+++ b/src/cmd/gc/lex.c
@@ -84,16 +84,8 @@ main(int argc, char *argv[])
 	curio.peekc = 0;
 	curio.peekc1 = 0;
 
-	externdcl = mal(sizeof(*externdcl));
-	externdcl->back = externdcl;
 	dclcontext = PEXTERN;
 
-	exportlist = mal(sizeof(*exportlist));
-	exportlist->back = exportlist;
-
-	typelist = mal(sizeof(*typelist));
-	typelist->back = typelist;
-
 	nerrors = 0;
 	yyparse();
 	runifacechecks();
diff --git a/src/cmd/gc/obj.c b/src/cmd/gc/obj.c
index 6bd66d79d..6d2154b28 100644
--- a/src/cmd/gc/obj.c
+++ b/src/cmd/gc/obj.c
@@ -38,27 +38,23 @@ dumpobj(void)
 void
 dumpglobls(void)
 {
-	Dcl *d;
-	Sym *s;
 	Node *n;
+	NodeList *l;
 
 	// add globals
-	for(d=externdcl; d!=D; d=d->forw) {
-		if(d->op != ONAME)
+	for(l=externdcl; l; l=l->next) {
+		n = l->n;
+		if(n->op != ONAME)
 			continue;
 
-		s = d->dsym;
-		if(s == S)
-			fatal("external nil");
-		n = d->dnode;
-		if(n == N || n->type == T)
-			fatal("external %S nil\n", s);
-
+		if(n->type == T)
+			fatal("external %#N nil type\n", n);
 		if(n->class == PFUNC)
 			continue;
-
 		dowidth(n->type);
-		ggloblnod(s->def, n->type->width);
+
+		// TODO(rsc): why is this not s/n->sym->def/n/ ?
+		ggloblnod(n->sym->def, n->type->width);
 	}
 }
 
diff --git a/src/cmd/gc/reflect.c b/src/cmd/gc/reflect.c
index 563c74082..02bc10ca5 100644
--- a/src/cmd/gc/reflect.c
+++ b/src/cmd/gc/reflect.c
@@ -8,7 +8,8 @@
  * runtime interface and reflection data structures
  */
 
-static Sym* dtypesym(Type*);
+static	NodeList*	signatlist;
+static	Sym*	dtypesym(Type*);
 
 static int
 sigcmp(Sig *a, Sig *b)
@@ -181,8 +182,8 @@ methods(Type *t)
 		a->tsym = methodsym(method, t);
 		a->type = methodfunc(f);
 
-		if(!a->isym->siggen) {
-			a->isym->siggen = 1;
+		if(!(a->isym->flags & SymSiggen)) {
+			a->isym->flags |= SymSiggen;
 			if(!eqtype(this, it)) {
 				if(oldlist == nil)
 					oldlist = pc;
@@ -198,8 +199,8 @@ methods(Type *t)
 			}
 		}
 
-		if(!a->tsym->siggen) {
-			a->tsym->siggen = 1;
+		if(!(a->tsym->flags & SymSiggen)) {
+			a->tsym->flags |= SymSiggen;
 			if(!eqtype(this, t)) {
 				if(oldlist == nil)
 					oldlist = pc;
@@ -447,7 +448,6 @@ typename(Type *t)
 {
 	Sym *s;
 	Node *n;
-	Dcl *d;
 
 	s = typesym(t);
 	if(s->def == N) {
@@ -460,13 +460,7 @@ typename(Type *t)
 		n->xoffset = 0;
 		s->def = n;
 
-		// copy to signatlist
-		d = dcl();
-		d->dsym = s;
-		d->dtype = t;
-		d->op = OTYPE;
-		d->forw = signatlist;
-		signatlist = d;
+		signatlist = list(signatlist, typenod(t));
 	}
 
 	n = nod(OADDR, s->def, N);
@@ -485,9 +479,9 @@ dtypesym(Type *t)
 	Type *t1;
 
 	s = typesym(t);
-	if(s->siggen)
+	if(s->flags & SymSiggen)
 		return s;
-	s->siggen = 1;
+	s->flags |= SymSiggen;
 
 	// special case (look for runtime below):
 	// when compiling package runtime,
@@ -652,27 +646,24 @@ void
 dumptypestructs(void)
 {
 	int i;
-	Dcl *d, *x;
+	NodeList *l;
+	Node *n;
 	Type *t;
 
 	// copy types from externdcl list to signatlist
-	for(d=externdcl; d!=D; d=d->forw) {
-		if(d->op != OTYPE)
+	for(l=externdcl; l; l=l->next) {
+		n = l->n;
+		if(n->op != OTYPE)
 			continue;
-		t = d->dtype;
-		x = mal(sizeof(*x));
-		x->op = OTYPE;
-		x->dtype = t;
-		x->forw = signatlist;
-		x->block = 0;
-		signatlist = x;
+		signatlist = list(signatlist, n);
 	}
 
 	// process signatlist
-	for(d=signatlist; d!=D; d=d->forw) {
-		if(d->op != OTYPE)
+	for(l=signatlist; l; l=l->next) {
+		n = l->n;
+		if(n->op != OTYPE)
 			continue;
-		t = d->dtype;
+		t = n->type;
 		dtypesym(t);
 		if(t->sym && !isptr[t->etype])
 			dtypesym(ptrto(t));
diff --git a/src/cmd/gc/subr.c b/src/cmd/gc/subr.c
index a0ef878f1..9ed434b58 100644
--- a/src/cmd/gc/subr.c
+++ b/src/cmd/gc/subr.c
@@ -307,16 +307,6 @@ remal(void *p, int32 on, int32 n)
 	return p;
 }
 
-Dcl*
-dcl(void)
-{
-	Dcl *d;
-
-	d = mal(sizeof(*d));
-	d->lineno = lineno;
-	return d;
-}
-
 extern int yychar;
 Node*
 nod(int op, Node *nleft, Node *nright)
@@ -965,9 +955,9 @@ Tpretty(Fmt *fp, Type *t)
 				fmtprint(fp, "%lS", s);
 			if(strcmp(s->package, package) != 0)
 				return 0;
-			if(s->imported)
+			if(s->flags & SymImported)
 				return 0;
-			if(t->vargen || !s->export) {
+			if(t->vargen || !(s->flags & (SymExport|SymPackage))) {
 				fmtprint(fp, "·%s", filename);
 				if(t->vargen)
 					fmtprint(fp, "·%d", t->vargen);
@@ -1244,7 +1234,7 @@ Nconv(Fmt *fp)
 			break;
 		}
 		fmtprint(fp, "%O-%S G%ld%J", n->op,
-			n->sym, n->sym->vargen, n);
+			n->sym, n->vargen, n);
 		goto ptyp;
 
 	case OREGISTER:
@@ -1284,7 +1274,7 @@ Nconv(Fmt *fp)
 		break;
 	}
 	if(n->sym != S)
-		fmtprint(fp, " %S G%ld", n->sym, n->sym->vargen);
+		fmtprint(fp, " %S G%ld", n->sym, n->vargen);
 
 ptyp:
 	if(n->type != T)
@@ -1935,30 +1925,32 @@ void
 frame(int context)
 {
 	char *p;
-	Dcl *d;
+	NodeList *l;
+	Node *n;
 	int flag;
 
 	p = "stack";
-	d = autodcl;
+	l = autodcl;
 	if(context) {
 		p = "external";
-		d = externdcl;
+		l = externdcl;
 	}
 
 	flag = 1;
-	for(; d!=D; d=d->forw) {
-		switch(d->op) {
+	for(; l; l=l->next) {
+		n = l->n;
+		switch(n->op) {
 		case ONAME:
 			if(flag)
 				print("--- %s frame ---\n", p);
-			print("%O %S G%ld T\n", d->op, d->dsym, d->dnode->vargen, d->dnode->type);
+			print("%O %S G%ld T\n", n->op, n->sym, n->vargen, n->type);
 			flag = 0;
 			break;
 
 		case OTYPE:
 			if(flag)
 				print("--- %s frame ---\n", p);
-			print("%O %T\n", d->op, d->dnode);
+			print("%O %T\n", n->op, n->type);
 			flag = 0;
 			break;
 		}
@@ -2520,9 +2512,9 @@ expand0(Type *t, int followptr)
 		for(f=u->type; f!=T; f=f->down) {
 			if(!exportname(f->sym->name) && strcmp(f->sym->package, package) != 0)
 				continue;
-			if(f->sym->uniq)
+			if(f->sym->flags & SymUniq)
 				continue;
-			f->sym->uniq = 1;
+			f->sym->flags |= SymUniq;
 			sl = mal(sizeof(*sl));
 			sl->field = f;
 			sl->link = slist;
@@ -2537,9 +2529,9 @@ expand0(Type *t, int followptr)
 		for(f=u->method; f!=T; f=f->down) {
 			if(!exportname(f->sym->name) && strcmp(f->sym->package, package) != 0)
 				continue;
-			if(f->sym->uniq)
+			if(f->sym->flags & SymUniq)
 				continue;
-			f->sym->uniq = 1;
+			f->sym->flags |= SymUniq;
 			sl = mal(sizeof(*sl));
 			sl->field = f;
 			sl->link = slist;
@@ -2601,7 +2593,7 @@ expandmeth(Sym *s, Type *t)
 
 	// check each method to be uniquely reachable
 	for(sl=slist; sl!=nil; sl=sl->link) {
-		sl->field->sym->uniq = 0;
+		sl->field->sym->flags &= ~SymUniq;
 		for(d=0; d<nelem(dotlist); d++) {
 			c = adddot1(sl->field->sym, t, d, &f);
 			if(c == 0)