change representation of strings

R=r
OCL=27293
CL=27293

src/cmd/6g/cgen.c

@@ -212,8 +212,8 @@ cgen(Node *n, Node *res)
 		break;
 
 	case OLEN:
-		if(istype(nl->type, TSTRING) || istype(nl->type, TMAP)) {
-			// both string and map have len in the first 32-bit word.
+		if(istype(nl->type, TMAP)) {
+			// map hsd len in the first 32-bit word.
 			// a zero pointer means zero length
 			regalloc(&n1, types[tptr], res);
 			cgen(nl, &n1);
@@ -233,7 +233,9 @@ cgen(Node *n, Node *res)
 			regfree(&n1);
 			break;
 		}
-		if(isslice(nl->type)) {
+		if(istype(nl->type, TSTRING) || isslice(nl->type)) {
+			// both slice and string have len in the first 32-bit word.
+			// a zero pointer means zero length
 			regalloc(&n1, types[tptr], res);
 			agen(nl, &n1);
 			n1.op = OINDREG;

src/cmd/6g/gg.h

@@ -45,7 +45,7 @@ EXTERN	Biobuf*	bout;
 EXTERN	int32	dynloc;
 EXTERN	uchar	reg[D_NONE];
 EXTERN	int32	pcloc;		// instruction counter
-EXTERN	String	emptystring;
+EXTERN	Strlit	emptystring;
 extern	char*	anames[];
 EXTERN	Hist*	hist;
 EXTERN	Prog	zprog;

src/cmd/6g/gsubr.c

@@ -152,7 +152,7 @@ ggloblsym(Sym *s, int32 width, int dupok)
 
 	p = gins(AGLOBL, N, N);
 	p->from.type = D_EXTERN;
-	if(s == symstringo)
+	if(s == symstringl || s == symstringc)
 		p->from.type = D_STATIC;
 	p->from.index = D_NONE;
 	p->from.sym = s;
@@ -170,6 +170,7 @@ isfat(Type *t)
 	switch(t->etype) {
 	case TSTRUCT:
 	case TARRAY:
+	case TSTRING:
 	case TINTER:	// maybe remove later
 	case TDDD:	// maybe remove later
 		return 1;
@@ -1146,10 +1147,9 @@ naddr(Node *n, Addr *a)
 			break;
 		case CTSTR:
 			a->etype = simtype[n->etype];
-			a->sym = symstringo;
-			a->type = D_ADDR;
-			a->index = D_STATIC;
-			a->offset = symstringo->offset;
+			a->sym = symstringl;
+			a->type = D_STATIC;
+			a->offset = symstringl->offset;
 			stringpool(n);
 			break;
 		case CTBOOL:

src/cmd/6g/obj.c

@@ -261,6 +261,10 @@ dumpfuncs(void)
 	}
 }
 
+/*
+ * dump the characters of the string
+ * pool into the array symstringc
+ */
 void
 datastring(char *s, int len)
 {
@@ -273,7 +277,7 @@ datastring(char *s, int len)
 	ao.type = D_STATIC;
 	ao.index = D_NONE;
 	ao.etype = TINT32;
-	ao.sym = symstringo;
+	ao.sym = symstringc;
 	ao.offset = 0;		// fill in
 
 	// constant
@@ -288,7 +292,7 @@ datastring(char *s, int len)
 
 		// .stringo<>+oo, [NSNAME], $"xxx"
 		p->from = ao;
-		p->from.offset = stringo;
+		p->from.offset = stringc;
 
 		p->from.scale = NSNAME;
 		if(w+8 > len)
@@ -298,23 +302,29 @@ datastring(char *s, int len)
 		p->to.type = D_SCONST;
 		p->to.offset = len;
 		memmove(p->to.sval, s+w, p->from.scale);
-		stringo += p->from.scale;
+		stringc += p->from.scale;
 	}
 }
 
+/*
+ * dump the strings into thye pool
+ * symstingl that consists of a pointer
+ * to the characters and a count
+ */
 void
 dumpstrings(void)
 {
 	Pool *l;
 	Prog *p;
-	Addr ac, ao;
-	int32 wi;
+	Addr ac, ao, ap;
+	int32 wi, wp, ws;
 
 	if(poolist == nil)
 		return;
 
 	memset(&ac, 0, sizeof(ac));
 	memset(&ao, 0, sizeof(ao));
+	memset(&ap, 0, sizeof(ap));
 
 	// constant
 	ac.type = D_CONST;
@@ -325,26 +335,44 @@ dumpstrings(void)
 	ao.type = D_STATIC;
 	ao.index = D_NONE;
 	ao.etype = TINT32;
-	ao.sym = symstringo;
+	ao.sym = symstringl;
 	ao.offset = 0;			// fill in
 
-	wi = types[TINT32]->width;
+	// $string len+ptr
+	ap.type = D_ADDR;
+	ap.index = D_STATIC;
+	ap.etype = TINT32;
+	ap.sym = symstringc;
+	ap.offset = 0;			// fill in
+
+	wi = types[TUINT32]->width;
+	wp = types[tptr]->width;
+	ws = types[TSTRING]->width;
 
 	// lay out (count+string)
 	for(l=poolist; l!=nil; l=l->link) {
 
+		// .stringl<>+ol, wp, $.stringc<>+oc
 		p = pc;
 		gins(ADATA, N, N);
+		p->from = ao;
+		p->from.offset = stringl;
+		p->from.scale = wp;
+		p->to = ap;
+		p->to.offset = stringc;
+		stringl += wp;
 
-		// .stringo<>+xx, wi, $len
-		stringo = rnd(stringo, wi);
+		// .stringl<>+ol, wi, $len
+		p = pc;
+		gins(ADATA, N, N);
 		p->from = ao;
-		p->from.offset = stringo;
+		p->from.offset = stringl;
 		p->from.scale = wi;
 		p->to = ac;
 		p->to.offset = l->sval->len;
-		stringo += wi;
+		stringl += wi;
 
+		stringl = rnd(stringl, ws);
 		datastring(l->sval->s, l->sval->len);
 	}
 }
@@ -361,11 +389,12 @@ dstringptr(Sym *s, int off, char *str)
 	p->from.sym = s;
 	p->from.offset = off;
 	p->from.scale = widthptr;
+
 	p->to.type = D_ADDR;
 	p->to.index = D_STATIC;
 	p->to.etype = TINT32;
-	p->to.sym = symstringo;
-	p->to.offset = stringo;
+	p->to.sym = symstringc;
+	p->to.offset = stringc;
 	off += widthptr;
 
 	datastring(str, strlen(str)+1);

src/cmd/gc/align.c

@@ -171,8 +171,8 @@ dowidth(Type *t)
 	case TANY:		// implemented as pointer
 		w = widthptr;
 		break;
-	case TSTRING:		// implemented as pointer
-		w = widthptr;
+	case TSTRING:
+		w = sizeof_String;
 		break;
 	case TARRAY:
 		if(t->type == T)
@@ -312,7 +312,6 @@ typeinit(int lex)
 	/* simple aliases */
 	simtype[TMAP] = tptr;
 	simtype[TCHAN] = tptr;
-	simtype[TSTRING] = tptr;
 	simtype[TFUNC] = tptr;
 
 	/* pick up the backend typedefs */
@@ -348,6 +347,9 @@ typeinit(int lex)
 	Array_nel = rnd(Array_array+widthptr, types[TUINT32]->width);
 	Array_cap = rnd(Array_nel+types[TUINT32]->width, types[TUINT32]->width);
 	sizeof_Array = rnd(Array_cap+types[TUINT32]->width, maxround);
+
+	// string is same as slice wo the cap
+	sizeof_String = rnd(Array_nel+types[TUINT32]->width, maxround);
 }
 
 /*

src/cmd/gc/const.c

@@ -237,7 +237,7 @@ tostr(Val v)
 {
 	Rune rune;
 	int l;
-	String *s;
+	Strlit *s;
 
 	switch(v.ctype) {
 	case CTINT:
@@ -281,7 +281,7 @@ evconst(Node *n)
 {
 	Node *nl, *nr;
 	int32 len;
-	String *str;
+	Strlit *str;
 	int wl, wr, lno, et;
 	Val v;
 	Mpint b;

src/cmd/gc/dcl.c

@@ -664,7 +664,7 @@ stotype(Node *n, int et, Type **t)
 {
 	Type *f, *t1;
 	Iter save;
-	String *note;
+	Strlit *note;
 	int lno;
 
 	lno = lineno;

src/cmd/gc/go.h

@@ -50,12 +50,10 @@ enum
 /*
  * note this is the representation
  * of the compilers string literals,
- * it happens to also be the runtime
- * representation, ignoring sizes and
- * alignment, but that may change.
+ * it is not the runtime representation
  */
-typedef	struct	String	String;
-struct	String
+typedef	struct	Strlit	Strlit;
+struct	Strlit
 {
 	int32	len;
 	char	s[3];	// variable
@@ -124,7 +122,7 @@ struct	Val
 		short	bval;		// bool value CTBOOL
 		Mpint*	xval;		// int CTINT
 		Mpflt*	fval;		// float CTFLT
-		String*	sval;		// string CTSTR
+		Strlit*	sval;		// string CTSTR
 	} u;
 };
 
@@ -167,7 +165,7 @@ struct	Type
 
 	// TFIELD
 	Type*	down;		// also used in TMAP
-	String*	note;			// literal string annotation
+	Strlit*	note;		// literal string annotation
 
 	// TARRAY
 	int32	bound;		// negative is dynamic array
@@ -468,14 +466,16 @@ struct Sig
 typedef	struct	Pool Pool;
 struct	Pool
 {
-	String*	sval;
+	Strlit*	sval;
 	Pool*	link;
 };
 
 EXTERN	Pool*	poolist;
 EXTERN	Pool*	poolast;
-EXTERN	Sym*	symstringo;	// string objects
-EXTERN	int32	stringo;	// size of string objects
+EXTERN	Sym*	symstringl;	// string literals
+EXTERN	Sym*	symstringc;	// string characters
+EXTERN	int32	stringl;	// size of string literals
+EXTERN	int32	stringc;	// size of string characters
 
 typedef	struct	Io	Io;
 struct	Io
@@ -512,11 +512,24 @@ struct Idir
  * 	uchar	cap[4];		// allocated number of elements
  * } Array;
  */
-EXTERN	int	Array_array;	// runtime offsetof(Array,array)
-EXTERN	int	Array_nel;	// runtime offsetof(Array,nel)
+EXTERN	int	Array_array;	// runtime offsetof(Array,array) - same for String
+EXTERN	int	Array_nel;	// runtime offsetof(Array,nel) - same for String
 EXTERN	int	Array_cap;	// runtime offsetof(Array,cap)
 EXTERN	int	sizeof_Array;	// runtime sizeof(Array)
 
+
+/*
+ * note this is the runtime representation
+ * of the compilers strings.
+ *
+ * typedef	struct
+ * {				// must not move anything
+ * 	uchar	array[8];	// pointer to data
+ * 	uchar	nel[4];		// number of elements
+ * } String;
+ */
+EXTERN	int	sizeof_String;	// runtime sizeof(String)
+
 EXTERN	Dlist	dotlist[10];	// size is max depth of embeddeds
 
 EXTERN	Io	curio;

src/cmd/gc/lex.c

@@ -66,7 +66,8 @@ main(int argc, char *argv[])
 	lexinit();
 	typeinit(LBASETYPE);
 
-	symstringo = lookup(".stringo");	// strings
+	symstringl = lookup(".stringl");	// string literals (ptr to char and count)
+	symstringc = lookup(".stringc");	// string characters
 
 	lineno = 1;
 	block = 1;
@@ -212,7 +213,7 @@ addidir(char* dir)
 }
 
 int
-findpkg(String *name)
+findpkg(Strlit *name)
 {
 	static char* goroot;
 	Idir* p;
@@ -514,7 +515,7 @@ l0:
 			cp = remal(cp, clen, 1);
 			cp[clen++] = 0;
 		} while(clen & MAXALIGN);
-		yylval.val.u.sval = (String*)cp;
+		yylval.val.u.sval = (Strlit*)cp;
 		yylval.val.ctype = CTSTR;
 		DBG("lex: string literal\n");
 		return LLITERAL;

src/cmd/gc/obj.c

@@ -484,8 +484,16 @@ dumpsignatures(void)
 		dumpsigt(progt, ifacet, rcvrt, methodt, s);
 	}
 
-	if(stringo > 0)
-		ggloblsym(symstringo, stringo, 0);
+	if(stringl > 0) {
+		stringl = rnd(stringl, maxround);
+		ggloblsym(symstringl, stringl, 0);
+		if(stringc == 0)
+			stringc = 1;
+	}
+	if(stringc > 0) {
+		stringc = rnd(stringc, maxround);
+		ggloblsym(symstringc, stringc, 0);
+	}
 }
 
 void
@@ -511,10 +519,7 @@ stringpool(Node *n)
 		poolast->link = p;
 	poolast = p;
 
-	w = types[TINT32]->width;
-	symstringo->offset += w;		// len
-	symstringo->offset += p->sval->len;	// str[len]
-	symstringo->offset = rnd(symstringo->offset, w);
+	symstringl->offset += types[TSTRING]->width;
 }
 
 Sig*

src/cmd/gc/subr.c

@@ -1361,10 +1361,10 @@ int
 Zconv(Fmt *fp)
 {
 	Rune r;
-	String *sp;
+	Strlit *sp;
 	char *s, *se;
 
-	sp = va_arg(fp->args, String*);
+	sp = va_arg(fp->args, Strlit*);
 	if(sp == nil)
 		return fmtstrcpy(fp, "<nil>");
 

src/lib/reflect/typestring.c

@@ -2,11 +2,39 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-extern char gotypestrings[];	// really a go String, but we don't have the definition here
 
-void FLUSH(void*) { }
+extern	char	gotypestrings[];	// 4-byte count followed by byte[count]
+
+void
+FLUSH(void*)
+{
+}
+
+typedef	struct	String	String;
+struct	String
+{
+	char*	str;
+	char	len[4];
+	char	cap[4];
+};
+
+void
+reflect·typestrings(String str)
+{
+	char *s;
+	int i;
 
-void reflect·typestrings(void *s) {
 	s = gotypestrings;
-	FLUSH(&s);
+
+	// repeat the count twice
+	// once for len, once for cap
+	for(i=0; i<4; i++) {
+		str.len[i] = s[i];
+		str.cap[i] = s[i];
+	}
+
+	// and the pointer
+	str.str = s+4;
+
+	FLUSH(&str);
 }

src/runtime/amd64/traceback.c

@@ -79,7 +79,7 @@ traceback(byte *pc0, byte *sp, G *g)
 
 // func caller(n int) (pc uint64, file string, line int, ok bool)
 void
-sys·Caller(int32 n, uint64 retpc, string retfile, int32 retline, bool retbool)
+sys·Caller(int32 n, uint64 retpc, String retfile, int32 retline, bool retbool)
 {
 	uint64 pc;
 	byte *sp;
@@ -94,7 +94,7 @@ sys·Caller(int32 n, uint64 retpc, string retfile, int32 retline, bool retbool)
 	error:
 		retpc = 0;
 		retline = 0;
-		retfile = nil;
+		retfile = emptystring;
 		retbool = false;
 		FLUSH(&retpc);
 		FLUSH(&retfile);

src/runtime/iface.c

@@ -560,13 +560,13 @@ sys·printinter(Iface i)
 }
 
 void
-sys·Reflect(Iface i, uint64 retit, string rettype, bool retindir)
+sys·Reflect(Iface i, uint64 retit, String rettype, bool retindir)
 {
 	int32 wid;
 
 	if(i.type == nil) {
 		retit = 0;
-		rettype = nil;
+		rettype = emptystring;
 		retindir = false;
 	} else {
 		retit = (uint64)i.data;
@@ -651,7 +651,7 @@ static	struct {
 	"bool", 4+1, AMEM, sizeof(bool),
 
 	// string compare is special
-	"string", 6+1, ASTRING, sizeof(string),
+	"string", 6+1, ASTRING, sizeof(String),
 
 	// generic types, identified by prefix
 	"*", 1, AMEM, sizeof(uintptr),
@@ -661,18 +661,15 @@ static	struct {
 };
 
 static Sigt*
-fakesigt(string type, bool indir)
+fakesigt(String type, bool indir)
 {
 	Sigt *sigt;
 	uint32 h;
 	int32 i, locked;
 
-	if(type == nil)
-		type = emptystring;
-
 	h = 0;
-	for(i=0; i<type->len; i++)
-		h = h*37 + type->str[i];
+	for(i=0; i<type.len; i++)
+		h = h*37 + type.str[i];
 	h += indir;
 	h %= nelem(fake);
 
@@ -683,8 +680,8 @@ fakesigt(string type, bool indir)
 			// don't need to compare indir.
 			// same type string but different indir will have
 			// different hashes.
-			if(mcmp(sigt->name, type->str, type->len) == 0)
-			if(sigt->name[type->len] == '\0') {
+			if(mcmp(sigt->name, type.str, type.len) == 0)
+			if(sigt->name[type.len] == '\0') {
 				if(locked)
 					unlock(&ifacelock);
 				return sigt;
@@ -693,8 +690,8 @@ fakesigt(string type, bool indir)
 	}
 
 	sigt = malloc(sizeof(*sigt));
-	sigt->name = malloc(type->len + 1);
-	mcpy(sigt->name, type->str, type->len);
+	sigt->name = malloc(type.len + 1);
+	mcpy(sigt->name, type.str, type.len);
 
 	sigt->alg = AFAKE;
 	sigt->width = 1;  // small width
@@ -719,16 +716,15 @@ fakesigt(string type, bool indir)
 }
 
 static int32
-cmpstringchars(string a, uint8 *b)
+cmpstringchars(String a, uint8 *b)
 {
 	int32 i;
 	byte c1, c2;
 
 	for(i=0;; i++) {
-		if(i == a->len)
-			c1 = 0;
-		else
-			c1 = a->str[i];
+		c1 = 0;
+		if(i < a.len)
+			c1 = a.str[i];
 		c2 = b[i];
 		if(c1 < c2)
 			return -1;
@@ -740,7 +736,7 @@ cmpstringchars(string a, uint8 *b)
 }
 
 static Sigt*
-findtype(string type, bool indir)
+findtype(String type, bool indir)
 {
 	int32 i, lo, hi, m;
 
@@ -761,7 +757,7 @@ findtype(string type, bool indir)
 
 
 void
-sys·Unreflect(uint64 it, string type, bool indir, Iface ret)
+sys·Unreflect(uint64 it, String type, bool indir, Iface ret)
 {
 	Sigt *sigt;
 

src/runtime/print.c

@@ -84,7 +84,7 @@ printf(int8 *s, ...)
 			prints(*(int8**)arg);
 			break;
 		case 'S':
-			sys·printstring(*(string*)arg);
+			sys·printstring(*(String*)arg);
 			break;
 		}
 		arg = narg;
@@ -239,16 +239,16 @@ sys·printpointer(void *p)
 }
 
 void
-sys·printstring(string v)
+sys·printstring(String v)
 {
 	extern int32 maxstring;
 
-	if(v != nil) {
-		if(v->len > maxstring)
-			sys·write(1, "[invalid string]", 16);
-		else
-			sys·write(1, v->str, v->len);
+	if(v.len > maxstring) {
+		sys·write(1, "[invalid string]", 16);
+		return;
 	}
+	if(v.len > 0)
+		sys·write(1, v.str, v.len);
 }
 
 void

src/runtime/runtime.c

@@ -149,8 +149,8 @@ args(int32 c, uint8 **v)
 void
 goargs(void)
 {
-	string *gargv;
-	string *genvv;
+	String *gargv;
+	String *genvv;
 	int32 i, envc;
 
 	for(envc=0; argv[argc+1+envc] != 0; envc++)
@@ -177,17 +177,17 @@ getenv(int8 *s)
 {
 	int32 i, j, len;
 	byte *v, *bs;
-	string* envv;
+	String* envv;
 	int32 envc;
 
 	bs = (byte*)s;
 	len = findnull(bs);
-	envv = (string*)sys·Envs.array;
+	envv = (String*)sys·Envs.array;
 	envc = sys·Envs.nel;
 	for(i=0; i<envc; i++){
-		if(envv[i]->len <= len)
+		if(envv[i].len <= len)
 			continue;
-		v = envv[i]->str;
+		v = envv[i].str;
 		for(j=0; j<len; j++)
 			if(bs[j] != v[j])
 				goto nomatch;
@@ -332,23 +332,21 @@ memcopy(uint32 s, void *a, void *b)
 }
 
 static uint64
-strhash(uint32 s, string *a)
+strhash(uint32 s, String *a)
 {
 	USED(s);
-	if(*a == nil)
-		return memhash(emptystring->len, emptystring->str);
-	return memhash((*a)->len, (*a)->str);
+	return memhash((*a).len, (*a).str);
 }
 
 static uint32
-strequal(uint32 s, string *a, string *b)
+strequal(uint32 s, String *a, String *b)
 {
 	USED(s);
 	return cmpstring(*a, *b) == 0;
 }
 
 static void
-strprint(uint32 s, string *a)
+strprint(uint32 s, String *a)
 {
 	USED(s);
 	sys·printstring(*a);

src/runtime/runtime.h

@@ -51,7 +51,7 @@ typedef	struct	M		M;
 typedef	struct	Mem		Mem;
 typedef	union	Note		Note;
 typedef	struct	Stktop		Stktop;
-typedef	struct	String		*string;
+typedef	struct	String		String;
 typedef	struct	Usema		Usema;
 typedef	struct	SigTab		SigTab;
 typedef	struct	MCache		MCache;
@@ -110,13 +110,13 @@ union	Note
 };
 struct String
 {
+	byte*	str;
 	int32	len;
-	byte	str[1];
 };
 struct Iface
 {
-	Itype *type;
-	void *data;
+	Itype*	type;
+	void*	data;
 };
 
 struct	Array
@@ -209,9 +209,9 @@ enum
 // be closer to this form.
 struct	Func
 {
-	string	name;
-	string	type;	// go type string
-	string	src;	// src file name
+	String	name;
+	String	type;	// go type string
+	String	src;	// src file name
 	uint64	entry;	// entry pc
 	int64	frame;	// stack frame size
 	Array	pcln;	// pc/ln tab for this func
@@ -258,7 +258,7 @@ struct Defer
  * external data
  */
 extern	Alg	algarray[Amax];
-extern	string	emptystring;
+extern	String	emptystring;
 G*	allg;
 int32	goidgen;
 extern	int32	gomaxprocs;
@@ -293,8 +293,8 @@ void	mcpy(byte*, byte*, uint32);
 int32	mcmp(byte*, byte*, uint32);
 void	mmov(byte*, byte*, uint32);
 void*	mal(uint32);
-uint32	cmpstring(string, string);
-string	gostring(byte*);
+uint32	cmpstring(String, String);
+String	gostring(byte*);
 void	initsig(void);
 int32	gotraceback(void);
 void	traceback(uint8 *pc, uint8 *sp, G* gp);
@@ -343,7 +343,7 @@ void	free(void *v);
 #pragma	varargck	type	"p"	uintptr
 #pragma	varargck	type	"s"	int8*
 #pragma	varargck	type	"s"	uint8*
-#pragma	varargck	type	"S"	string
+#pragma	varargck	type	"S"	String
 
 // TODO(rsc): Remove. These are only temporary,
 // for the mark and sweep collector.
@@ -424,17 +424,17 @@ void	sys_printbool(bool);
 void	sys_printfloat(float64);
 void	sys_printint(int64);
 void	sys_printinter(Iface);
-void	sys_printstring(string);
+void	sys_printstring(String);
 void	sys_printpc(void*);
 void	sys_printpointer(void*);
 void	sys_printuint(uint64);
 void	sys_printhex(uint64);
 void	sys_printarray(Array);
-void	sys_catstring(string, string, string);
-void	sys_cmpstring(string, string, int32);
-void	sys_slicestring(string, int32, int32, string);
-void	sys_indexstring(string, int32, byte);
-void	sys_intstring(int64, string);
+void	sys_catstring(String, String, String);
+void	sys_cmpstring(String, String, int32);
+void	sys_slicestring(String, int32, int32, String);
+void	sys_indexstring(String, int32, byte);
+void	sys_intstring(int64, String);
 
 /*
  * wrapped for go users

src/runtime/string.c

@@ -4,8 +4,7 @@
 
 #include "runtime.h"
 
-static	int32	empty		= 0;
-string	emptystring	= (string)∅
+String	emptystring;
 
 int32
 findnull(byte *s)
@@ -21,49 +20,47 @@ findnull(byte *s)
 
 int32 maxstring;
 
-string
+String
 gostringsize(int32 l)
 {
-	string s;
+	String s;
 
-	s = mal(sizeof(s->len)+l+1);
-	s->len = l;
+	if(l == 0)
+		return emptystring;
+	s.str = mal(l);
+	s.len = l;
 	if(l > maxstring)
 		maxstring = l;
 	return s;
 }
 
-string
+String
 gostring(byte *str)
 {
 	int32 l;
-	string s;
+	String s;
 
 	l = findnull(str);
 	s = gostringsize(l);
-	mcpy(s->str, str, l+1);
+	mcpy(s.str, str, l);
 	return s;
 }
 
 void
-sys·catstring(string s1, string s2, string s3)
+sys·catstring(String s1, String s2, String s3)
 {
-	uint32 l;
-
-	if(s1 == nil || s1->len == 0) {
+	if(s1.len == 0) {
 		s3 = s2;
 		goto out;
 	}
-	if(s2 == nil || s2->len == 0) {
+	if(s2.len == 0) {
 		s3 = s1;
 		goto out;
 	}
 
-	l = s1->len + s2->len;
-
-	s3 = gostringsize(l);
-	mcpy(s3->str, s1->str, s1->len);
-	mcpy(s3->str+s1->len, s2->str, s2->len);
+	s3 = gostringsize(s1.len + s2.len);
+	mcpy(s3.str, s1.str, s1.len);
+	mcpy(s3.str+s1.len, s2.str, s2.len);
 
 out:
 	FLUSH(&s3);
@@ -84,36 +81,31 @@ prbounds(int8* s, int32 a, int32 b, int32 c)
 }
 
 uint32
-cmpstring(string s1, string s2)
+cmpstring(String s1, String s2)
 {
 	uint32 i, l;
 	byte c1, c2;
 
-	if(s1 == nil)
-		s1 = emptystring;
-	if(s2 == nil)
-		s2 = emptystring;
-
-	l = s1->len;
-	if(s2->len < l)
-		l = s2->len;
+	l = s1.len;
+	if(s2.len < l)
+		l = s2.len;
 	for(i=0; i<l; i++) {
-		c1 = s1->str[i];
-		c2 = s2->str[i];
+		c1 = s1.str[i];
+		c2 = s2.str[i];
 		if(c1 < c2)
 			return -1;
 		if(c1 > c2)
 			return +1;
 	}
-	if(s1->len < s2->len)
+	if(s1.len < s2.len)
 		return -1;
-	if(s1->len > s2->len)
+	if(s1.len > s2.len)
 		return +1;
 	return 0;
 }
 
 void
-sys·cmpstring(string s1, string s2, int32 v)
+sys·cmpstring(String s1, String s2, int32 v)
 {
 	v = cmpstring(s1, s2);
 	FLUSH(&v);
@@ -138,62 +130,61 @@ strcmp(byte *s1, byte *s2)
 }
 
 void
-sys·slicestring(string si, int32 lindex, int32 hindex, string so)
+sys·slicestring(String si, int32 lindex, int32 hindex, String so)
 {
 	int32 l;
 
-	if(si == nil)
-		si = emptystring;
-
-	if(lindex < 0 || lindex > si->len ||
-	   hindex < lindex || hindex > si->len) {
+	if(lindex < 0 || lindex > si.len ||
+	   hindex < lindex || hindex > si.len) {
 		sys·printpc(&si);
 		prints(" ");
-		prbounds("slice", lindex, si->len, hindex);
+		prbounds("slice", lindex, si.len, hindex);
 	}
 
 	l = hindex-lindex;
-	so = gostringsize(l);
-	mcpy(so->str, si->str+lindex, l);
+	so.str = si.str + lindex;
+	so.len = l;
+
+//	alternate to create a new string
+//	so = gostringsize(l);
+//	mcpy(so.str, si.str+lindex, l);
+
 	FLUSH(&so);
 }
 
 void
-sys·indexstring(string s, int32 i, byte b)
+sys·indexstring(String s, int32 i, byte b)
 {
-	if(s == nil)
-		s = emptystring;
-
-	if(i < 0 || i >= s->len) {
+	if(i < 0 || i >= s.len) {
 		sys·printpc(&s);
 		prints(" ");
-		prbounds("index", 0, i, s->len);
+		prbounds("index", 0, i, s.len);
 	}
 
-	b = s->str[i];
+	b = s.str[i];
 	FLUSH(&b);
 }
 
 void
-sys·intstring(int64 v, string s)
+sys·intstring(int64 v, String s)
 {
 	s = gostringsize(8);
-	s->len = runetochar(s->str, v);
+	s.len = runetochar(s.str, v);
 	FLUSH(&s);
 }
 
 void
-sys·byteastring(byte *a, int32 l, string s)
+sys·byteastring(byte *a, int32 l, String s)
 {
 	s = gostringsize(l);
-	mcpy(s->str, a, l);
+	mcpy(s.str, a, l);
 	FLUSH(&s);
 }
 
 void
-sys·arraystring(Array b, string s)
+sys·arraystring(Array b, String s)
 {
 	s = gostringsize(b.nel);
-	mcpy(s->str, b.array, s->len);
+	mcpy(s.str, b.array, s.len);
 	FLUSH(&s);
 }

src/runtime/symtab.c

@@ -195,7 +195,7 @@ static void
 dosrcline(Sym *sym)
 {
 	static byte srcbuf[1000];
-	static string srcstring;
+	static String srcstring;
 	static int32 lno, incstart;
 	static int32 nf, nhist;
 	Func *f;