ref: f3ea55fc6440ca9bf08e472f2d5e1f14ee0f4273
dir: /jsparse.c/
#include "js.h"
#include "jslex.h"
#include "jsparse.h"
#include "jsstate.h"
#define nelem(a) (sizeof (a) / sizeof (a)[0])
#define LIST(h) jsP_newnode(J, AST_LIST, h, 0, 0, 0)
#define EXP0(x) jsP_newnode(J, EXP_ ## x, 0, 0, 0, 0)
#define EXP1(x,a) jsP_newnode(J, EXP_ ## x, a, 0, 0, 0)
#define EXP2(x,a,b) jsP_newnode(J, EXP_ ## x, a, b, 0, 0)
#define EXP3(x,a,b,c) jsP_newnode(J, EXP_ ## x, a, b, c, 0)
#define STM0(x) jsP_newnode(J, STM_ ## x, 0, 0, 0, 0)
#define STM1(x,a) jsP_newnode(J, STM_ ## x, a, 0, 0, 0)
#define STM2(x,a,b) jsP_newnode(J, STM_ ## x, a, b, 0, 0)
#define STM3(x,a,b,c) jsP_newnode(J, STM_ ## x, a, b, c, 0)
#define STM4(x,a,b,c,d) jsP_newnode(J, STM_ ## x, a, b, c, d)
#define TOKSTR jsP_tokenstring(J->lookahead)
static js_Ast *expression(js_State *J, int notin);
static js_Ast *assignment(js_State *J, int notin);
static js_Ast *memberexp(js_State *J);
static js_Ast *statement(js_State *J);
static js_Ast *funbody(js_State *J);
js_Ast *jsP_newnode(js_State *J, int type, js_Ast *a, js_Ast *b, js_Ast *c, js_Ast *d)
{
js_Ast *node = malloc(sizeof(js_Ast));
node->type = type;
node->line = J->lexline;
node->a = a;
node->b = b;
node->c = c;
node->d = d;
node->number = 0;
node->string = NULL;
node->gcnext = J->gcast;
J->gcast = node;
return node;
}
js_Ast *jsP_newstrnode(js_State *J, int type, const char *s)
{
js_Ast *node = jsP_newnode(J, type, 0, 0, 0, 0);
node->string = s;
return node;
}
js_Ast *jsP_newnumnode(js_State *J, int type, double n)
{
js_Ast *node = jsP_newnode(J, type, 0, 0, 0, 0);
node->number = n;
return node;
}
void jsP_freeparse(js_State *J)
{
js_Ast *node = J->gcast;
while (node) {
js_Ast *next = node->gcnext;
free(node);
node = next;
}
J->gcast = NULL;
}
/* Lookahead */
static inline void next(js_State *J)
{
J->lookahead = jsP_lex(J);
}
static inline int accept(js_State *J, int t)
{
if (J->lookahead == t) {
next(J);
return 1;
}
return 0;
}
static inline void expect(js_State *J, int t)
{
if (accept(J, t))
return;
jsP_error(J, "unexpected token: %s (expected %s)", TOKSTR, jsP_tokenstring(t));
}
static void semicolon(js_State *J)
{
if (J->lookahead == ';') {
next(J);
return;
}
if (J->newline || J->lookahead == '}' || J->lookahead == 0)
return;
jsP_error(J, "unexpected token: %s (expected ';')", TOKSTR);
}
/* Literals */
static inline int findword(const char *s, const char **list, int num)
{
int l = 0;
int r = num - 1;
while (l <= r) {
int m = (l + r) >> 1;
int c = strcmp(s, list[m]);
if (c < 0)
r = m - 1;
else if (c > 0)
l = m + 1;
else
return m;
}
return -1;
}
static const char *futurewords[] = {
"class", "const", "enum", "export", "extends", "import", "super",
};
static const char *strictfuturewords[] = {
"implements", "interface", "let", "package", "private", "protected",
"public", "static", "yield",
};
static void checkfutureword(js_State *J, const char *s)
{
if (findword(s, futurewords, nelem(futurewords)) >= 0)
jsP_error(J, "'%s' is a future reserved word", s);
if (J->strict && findword(s, strictfuturewords, nelem(strictfuturewords)) >= 0)
jsP_error(J, "'%s' is a strict mode future reserved word", s);
}
static js_Ast *identifier(js_State *J)
{
js_Ast *a;
if (J->lookahead == TK_IDENTIFIER) {
checkfutureword(J, J->text);
a = jsP_newstrnode(J, AST_IDENTIFIER, J->text);
next(J);
return a;
}
jsP_error(J, "unexpected token: %s (expected identifier)", TOKSTR);
return NULL;
}
static js_Ast *identifieropt(js_State *J)
{
if (J->lookahead == TK_IDENTIFIER)
return identifier(J);
return NULL;
}
static js_Ast *identifiername(js_State *J)
{
if (J->lookahead == TK_IDENTIFIER || J->lookahead >= TK_BREAK) {
js_Ast *a = jsP_newstrnode(J, AST_IDENTIFIER, J->text);
next(J);
return a;
}
jsP_error(J, "unexpected token: %s (expected identifier or keyword)", TOKSTR);
return NULL;
}
static js_Ast *arrayelement(js_State *J)
{
if (J->lookahead == ',')
return EXP0(UNDEF);
return assignment(J, 0);
}
static js_Ast *arrayliteral(js_State *J)
{
js_Ast *head, *tail;
if (J->lookahead == ']')
return NULL;
head = tail = LIST(arrayelement(J));
while (accept(J, ',')) {
if (J->lookahead != ']')
tail = tail->b = LIST(arrayelement(J));
}
return head;
}
static js_Ast *propname(js_State *J)
{
js_Ast *name;
if (J->lookahead == TK_NUMBER) {
name = jsP_newnumnode(J, AST_NUMBER, J->number);
next(J);
} else if (J->lookahead == TK_STRING) {
name = jsP_newstrnode(J, AST_STRING, J->text);
next(J);
} else {
name = identifiername(J);
}
return name;
}
static js_Ast *propassign(js_State *J)
{
js_Ast *name, *value, *arg, *body;
name = propname(J);
if (J->lookahead != ':' && name->type == AST_IDENTIFIER) {
if (!strcmp(name->string, "get")) {
name = propname(J);
expect(J, '(');
expect(J, ')');
body = funbody(J);
return EXP2(PROP_GET, name, body);
}
if (!strcmp(name->string, "set")) {
name = propname(J);
expect(J, '(');
arg = identifier(J);
expect(J, ')');
body = funbody(J);
return EXP3(PROP_SET, name, arg, body);
}
}
expect(J, ':');
value = assignment(J, 0);
return EXP2(PROP_VAL, name, value);
}
static js_Ast *objectliteral(js_State *J)
{
js_Ast *head, *tail;
if (J->lookahead == '}')
return NULL;
head = tail = LIST(propassign(J));
while (accept(J, ',')) {
if (J->lookahead == '}')
break;
tail = tail->b = LIST(propassign(J));
}
return head;
}
/* Functions */
static js_Ast *parameters(js_State *J)
{
js_Ast *head, *tail;
if (J->lookahead == ')')
return NULL;
head = tail = LIST(identifier(J));
while (accept(J, ',')) {
tail = tail->b = LIST(identifier(J));
}
return head;
}
static js_Ast *fundec(js_State *J)
{
js_Ast *a, *b, *c;
a = identifier(J);
expect(J, '(');
b = parameters(J);
expect(J, ')');
c = funbody(J);
return jsP_newnode(J, AST_FUNDEC, a, b, c, 0);
}
static js_Ast *funstm(js_State *J)
{
js_Ast *a, *b, *c;
a = identifier(J);
expect(J, '(');
b = parameters(J);
expect(J, ')');
c = funbody(J);
/* rewrite function statement as "var X = function X() {}" */
return STM1(VAR, LIST(EXP2(VAR, a, EXP3(FUN, a, b, c))));
}
static js_Ast *funexp(js_State *J)
{
js_Ast *a, *b, *c;
a = identifieropt(J);
expect(J, '(');
b = parameters(J);
expect(J, ')');
c = funbody(J);
return EXP3(FUN, a, b, c);
}
/* Expressions */
static js_Ast *primary(js_State *J)
{
js_Ast *a;
if (J->lookahead == TK_IDENTIFIER) {
a = jsP_newstrnode(J, AST_IDENTIFIER, J->text);
next(J);
return a;
}
if (J->lookahead == TK_STRING) {
a = jsP_newstrnode(J, AST_STRING, J->text);
next(J);
return a;
}
if (J->lookahead == TK_REGEXP) {
a = jsP_newstrnode(J, AST_REGEXP, J->text);
a->number = J->number;
next(J);
return a;
}
if (J->lookahead == TK_NUMBER) {
a = jsP_newnumnode(J, AST_NUMBER, J->number);
next(J);
return a;
}
if (accept(J, TK_THIS)) return EXP0(THIS);
if (accept(J, TK_NULL)) return EXP0(NULL);
if (accept(J, TK_TRUE)) return EXP0(TRUE);
if (accept(J, TK_FALSE)) return EXP0(FALSE);
if (accept(J, '{')) { a = EXP1(OBJECT, objectliteral(J)); expect(J, '}'); return a; }
if (accept(J, '[')) { a = EXP1(ARRAY, arrayliteral(J)); expect(J, ']'); return a; }
if (accept(J, '(')) { a = expression(J, 0); expect(J, ')'); return a; }
jsP_error(J, "unexpected token in expression: %s", TOKSTR);
return NULL;
}
static js_Ast *arguments(js_State *J)
{
js_Ast *head, *tail;
if (J->lookahead == ')')
return NULL;
head = tail = LIST(assignment(J, 0));
while (accept(J, ',')) {
tail = tail->b = LIST(assignment(J, 0));
}
return head;
}
static js_Ast *newexp(js_State *J)
{
js_Ast *a, *b;
if (accept(J, TK_NEW)) {
a = memberexp(J);
if (accept(J, '(')) {
b = arguments(J);
expect(J, ')');
return EXP2(NEW, a, b);
}
return EXP1(NEW, a);
}
if (accept(J, TK_FUNCTION))
return funexp(J);
return primary(J);
}
static js_Ast *memberexp(js_State *J)
{
js_Ast *a = newexp(J);
loop:
if (accept(J, '.')) { a = EXP2(MEMBER, a, identifiername(J)); goto loop; }
if (accept(J, '[')) { a = EXP2(INDEX, a, expression(J, 0)); expect(J, ']'); goto loop; }
return a;
}
static js_Ast *callexp(js_State *J)
{
js_Ast *a = newexp(J);
loop:
if (accept(J, '.')) { a = EXP2(MEMBER, a, identifiername(J)); goto loop; }
if (accept(J, '[')) { a = EXP2(INDEX, a, expression(J, 0)); expect(J, ']'); goto loop; }
if (accept(J, '(')) { a = EXP2(CALL, a, arguments(J)); expect(J, ')'); goto loop; }
return a;
}
static js_Ast *postfix(js_State *J)
{
js_Ast *a = callexp(J);
if (!J->newline && accept(J, TK_INC)) return EXP1(POSTINC, a);
if (!J->newline && accept(J, TK_DEC)) return EXP1(POSTDEC, a);
return a;
}
static js_Ast *unary(js_State *J)
{
if (accept(J, TK_DELETE)) return EXP1(DELETE, unary(J));
if (accept(J, TK_VOID)) return EXP1(VOID, unary(J));
if (accept(J, TK_TYPEOF)) return EXP1(TYPEOF, unary(J));
if (accept(J, TK_INC)) return EXP1(PREINC, unary(J));
if (accept(J, TK_DEC)) return EXP1(PREDEC, unary(J));
if (accept(J, '+')) return EXP1(POS, unary(J));
if (accept(J, '-')) return EXP1(NEG, unary(J));
if (accept(J, '~')) return EXP1(BITNOT, unary(J));
if (accept(J, '!')) return EXP1(LOGNOT, unary(J));
return postfix(J);
}
static js_Ast *multiplicative(js_State *J)
{
js_Ast *a = unary(J);
loop:
if (accept(J, '*')) { a = EXP2(MUL, a, unary(J)); goto loop; }
if (accept(J, '/')) { a = EXP2(DIV, a, unary(J)); goto loop; }
if (accept(J, '%')) { a = EXP2(MOD, a, unary(J)); goto loop; }
return a;
}
static js_Ast *additive(js_State *J)
{
js_Ast *a = multiplicative(J);
loop:
if (accept(J, '+')) { a = EXP2(ADD, a, multiplicative(J)); goto loop; }
if (accept(J, '-')) { a = EXP2(SUB, a, multiplicative(J)); goto loop; }
return a;
}
static js_Ast *shift(js_State *J)
{
js_Ast *a = additive(J);
loop:
if (accept(J, TK_SHL)) { a = EXP2(SHL, a, additive(J)); goto loop; }
if (accept(J, TK_SHR)) { a = EXP2(SHR, a, additive(J)); goto loop; }
if (accept(J, TK_USHR)) { a = EXP2(USHR, a, additive(J)); goto loop; }
return a;
}
static js_Ast *relational(js_State *J, int notin)
{
js_Ast *a = shift(J);
loop:
if (accept(J, '<')) { a = EXP2(LT, a, shift(J)); goto loop; }
if (accept(J, '>')) { a = EXP2(GT, a, shift(J)); goto loop; }
if (accept(J, TK_LE)) { a = EXP2(LE, a, shift(J)); goto loop; }
if (accept(J, TK_GE)) { a = EXP2(GE, a, shift(J)); goto loop; }
if (accept(J, TK_INSTANCEOF)) { a = EXP2(INSTANCEOF, a, shift(J)); goto loop; }
if (!notin && accept(J, TK_IN)) { a = EXP2(IN, a, shift(J)); goto loop; }
return a;
}
static js_Ast *equality(js_State *J, int notin)
{
js_Ast *a = relational(J, notin);
loop:
if (accept(J, TK_EQ)) { a = EXP2(EQ, a, relational(J, notin)); goto loop; }
if (accept(J, TK_NE)) { a = EXP2(NE, a, relational(J, notin)); goto loop; }
if (accept(J, TK_STRICTEQ)) { a = EXP2(STRICTEQ, a, relational(J, notin)); goto loop; }
if (accept(J, TK_STRICTNE)) { a = EXP2(STRICTNE, a, relational(J, notin)); goto loop; }
return a;
}
static js_Ast *bitand(js_State *J, int notin)
{
js_Ast *a = equality(J, notin);
while (accept(J, '&'))
a = EXP2(BITAND, a, equality(J, notin));
return a;
}
static js_Ast *bitxor(js_State *J, int notin)
{
js_Ast *a = bitand(J, notin);
while (accept(J, '^'))
a = EXP2(BITXOR, a, bitand(J, notin));
return a;
}
static js_Ast *bitor(js_State *J, int notin)
{
js_Ast *a = bitxor(J, notin);
while (accept(J, '|'))
a = EXP2(BITOR, a, bitxor(J, notin));
return a;
}
static js_Ast *logand(js_State *J, int notin)
{
js_Ast *a = bitor(J, notin);
if (accept(J, TK_AND))
a = EXP2(LOGAND, a, logand(J, notin));
return a;
}
static js_Ast *logor(js_State *J, int notin)
{
js_Ast *a = logand(J, notin);
if (accept(J, TK_OR))
a = EXP2(LOGOR, a, logor(J, notin));
return a;
}
static js_Ast *conditional(js_State *J, int notin)
{
js_Ast *a, *b, *c;
a = logor(J, notin);
if (accept(J, '?')) {
b = assignment(J, 0);
expect(J, ':');
c = assignment(J, notin);
return EXP3(COND, a, b, c);
}
return a;
}
static js_Ast *assignment(js_State *J, int notin)
{
js_Ast *a = conditional(J, notin);
if (accept(J, '=')) return EXP2(ASS, a, assignment(J, notin));
if (accept(J, TK_MUL_ASS)) return EXP2(ASS_MUL, a, assignment(J, notin));
if (accept(J, TK_DIV_ASS)) return EXP2(ASS_DIV, a, assignment(J, notin));
if (accept(J, TK_MOD_ASS)) return EXP2(ASS_MOD, a, assignment(J, notin));
if (accept(J, TK_ADD_ASS)) return EXP2(ASS_ADD, a, assignment(J, notin));
if (accept(J, TK_SUB_ASS)) return EXP2(ASS_SUB, a, assignment(J, notin));
if (accept(J, TK_SHL_ASS)) return EXP2(ASS_SHL, a, assignment(J, notin));
if (accept(J, TK_SHR_ASS)) return EXP2(ASS_SHR, a, assignment(J, notin));
if (accept(J, TK_USHR_ASS)) return EXP2(ASS_USHR, a, assignment(J, notin));
if (accept(J, TK_AND_ASS)) return EXP2(ASS_BITAND, a, assignment(J, notin));
if (accept(J, TK_XOR_ASS)) return EXP2(ASS_BITXOR, a, assignment(J, notin));
if (accept(J, TK_OR_ASS)) return EXP2(ASS_BITOR, a, assignment(J, notin));
return a;
}
static js_Ast *expression(js_State *J, int notin)
{
js_Ast *a = assignment(J, notin);
while (accept(J, ','))
a = EXP2(COMMA, a, assignment(J, notin));
return a;
}
/* Statements */
static js_Ast *vardec(js_State *J, int notin)
{
js_Ast *a = identifier(J);
if (accept(J, '='))
return EXP2(VAR, a, assignment(J, notin));
return EXP1(VAR, a);
}
static js_Ast *vardeclist(js_State *J, int notin)
{
js_Ast *head, *tail;
head = tail = LIST(vardec(J, notin));
while (accept(J, ','))
tail = tail->b = LIST(vardec(J, notin));
return head;
}
static js_Ast *statementlist(js_State *J)
{
js_Ast *head, *tail;
if (J->lookahead == '}' || J->lookahead == TK_CASE || J->lookahead == TK_DEFAULT)
return NULL;
head = tail = LIST(statement(J));
while (J->lookahead != '}' && J->lookahead != TK_CASE && J->lookahead != TK_DEFAULT)
tail = tail->b = LIST(statement(J));
return head;
}
static js_Ast *caseclause(js_State *J)
{
js_Ast *a, *b;
if (accept(J, TK_CASE)) {
a = expression(J, 0);
expect(J, ':');
b = statementlist(J);
return STM2(CASE, a, b);
}
if (accept(J, TK_DEFAULT)) {
expect(J, ':');
a = statementlist(J);
return STM1(DEFAULT, a);
}
jsP_error(J, "unexpected token in switch: %s (expected 'case' or 'default')", TOKSTR);
return NULL;
}
static js_Ast *caselist(js_State *J)
{
js_Ast *head, *tail;
if (J->lookahead == '}')
return NULL;
head = tail = LIST(caseclause(J));
while (J->lookahead != '}')
tail = tail->b = LIST(caseclause(J));
return head;
}
static js_Ast *block(js_State *J)
{
js_Ast *a;
expect(J, '{');
a = statementlist(J);
expect(J, '}');
return STM1(BLOCK, a);
}
static js_Ast *forexpression(js_State *J, int end)
{
js_Ast *a = NULL;
if (J->lookahead != end)
a = expression(J, 0);
expect(J, end);
return a;
}
static js_Ast *forstatement(js_State *J)
{
js_Ast *a, *b, *c, *d;
expect(J, '(');
if (accept(J, TK_VAR)) {
a = vardeclist(J, 1);
if (accept(J, ';')) {
b = forexpression(J, ';');
c = forexpression(J, ')');
d = statement(J);
return STM4(FOR_VAR, a, b, c, d);
}
if (accept(J, TK_IN)) {
b = expression(J, 0);
expect(J, ')');
c = statement(J);
return STM3(FOR_IN_VAR, a, b, c);
}
jsP_error(J, "unexpected token in for-var-statement: %s", TOKSTR);
return NULL;
}
if (J->lookahead != ';')
a = expression(J, 1);
else
a = NULL;
if (accept(J, ';')) {
b = forexpression(J, ';');
c = forexpression(J, ')');
d = statement(J);
return STM4(FOR, a, b, c, d);
}
if (accept(J, TK_IN)) {
b = expression(J, 0);
expect(J, ')');
c = statement(J);
return STM3(FOR_IN, a, b, c);
}
jsP_error(J, "unexpected token in for-statement: %s", TOKSTR);
return NULL;
}
static js_Ast *statement(js_State *J)
{
js_Ast *a, *b, *c, *d;
if (J->lookahead == '{') {
return block(J);
}
if (accept(J, TK_VAR)) {
a = vardeclist(J, 0);
semicolon(J);
return STM1(VAR, a);
}
/* empty statement */
if (accept(J, ';')) {
return STM0(NOP);
}
if (accept(J, TK_IF)) {
expect(J, '(');
a = expression(J, 0);
expect(J, ')');
b = statement(J);
if (accept(J, TK_ELSE))
c = statement(J);
else
c = NULL;
return STM3(IF, a, b, c);
}
if (accept(J, TK_DO)) {
a = statement(J);
expect(J, TK_WHILE);
expect(J, '(');
b = expression(J, 0);
expect(J, ')');
semicolon(J);
return STM2(DO, a, b);
}
if (accept(J, TK_WHILE)) {
expect(J, '(');
a = expression(J, 0);
expect(J, ')');
b = statement(J);
return STM2(WHILE, a, b);
}
if (accept(J, TK_FOR)) {
return forstatement(J);
}
if (accept(J, TK_CONTINUE)) {
a = identifieropt(J);
semicolon(J);
return STM1(CONTINUE, a);
}
if (accept(J, TK_BREAK)) {
a = identifieropt(J);
semicolon(J);
return STM1(BREAK, a);
}
if (accept(J, TK_RETURN)) {
if (J->lookahead != ';' && J->lookahead != '}' && J->lookahead != 0)
a = expression(J, 0);
else
a = NULL;
semicolon(J);
return STM1(RETURN, a);
}
if (accept(J, TK_WITH)) {
expect(J, '(');
a = expression(J, 0);
expect(J, ')');
b = statement(J);
return STM2(WITH, a, b);
}
if (accept(J, TK_SWITCH)) {
expect(J, '(');
a = expression(J, 0);
expect(J, ')');
expect(J, '{');
b = caselist(J);
expect(J, '}');
return STM2(SWITCH, a, b);
}
if (accept(J, TK_THROW)) {
a = expression(J, 0);
semicolon(J);
return STM1(THROW, a);
}
if (accept(J, TK_TRY)) {
a = block(J);
b = c = d = NULL;
if (accept(J, TK_CATCH)) {
expect(J, '(');
b = identifier(J);
expect(J, ')');
c = block(J);
}
if (accept(J, TK_FINALLY)) {
d = block(J);
}
if (!b && !d)
jsP_error(J, "unexpected token in try: %s (expected 'catch' or 'finally')", TOKSTR);
return STM4(TRY, a, b, c, d);
}
if (accept(J, TK_DEBUGGER)) {
semicolon(J);
return STM0(DEBUGGER);
}
if (accept(J, TK_FUNCTION)) {
jsP_warning(J, "function statements are not standard");
return funstm(J);
}
/* labelled statement or expression statement */
if (J->lookahead == TK_IDENTIFIER) {
a = expression(J, 0);
if (a->type == AST_IDENTIFIER && accept(J, ':')) {
b = statement(J);
return STM2(LABEL, a, b);
}
semicolon(J);
return a;
}
/* expression statement */
a = expression(J, 0);
semicolon(J);
return a;
jsP_error(J, "unexpected token in statement: %s", TOKSTR);
return NULL;
}
/* Program */
static js_Ast *scriptelement(js_State *J)
{
if (accept(J, TK_FUNCTION))
return fundec(J);
return statement(J);
}
static js_Ast *script(js_State *J)
{
js_Ast *head, *tail;
if (J->lookahead == '}' || J->lookahead == 0)
return NULL;
head = tail = LIST(scriptelement(J));
while (J->lookahead != '}' && J->lookahead != 0)
tail = tail->b = LIST(scriptelement(J));
return head;
}
static js_Ast *funbody(js_State *J)
{
js_Ast *a;
expect(J, '{');
a = script(J);
expect(J, '}');
return a;
}
void jsP_warning(js_State *J, const char *fmt, ...)
{
va_list ap;
fprintf(stderr, "%s:%d: warning: ", J->filename, J->lexline);
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, "\n");
}
int jsP_error(js_State *J, const char *fmt, ...)
{
va_list ap;
fprintf(stderr, "%s:%d: error: ", J->filename, J->lexline);
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, "\n");
longjmp(J->jb, 1);
}
js_Ast *jsP_parse(js_State *J, const char *filename, const char *source)
{
js_Ast *p, *last;
jsP_initlex(J, filename, source);
if (setjmp(J->jb)) {
jsP_freeparse(J);
return NULL;
}
next(J);
p = script(J);
/* patch up global and eval code to return value of last expression */
last = p;
if (last) {
while (last->b)
last = last->b;
if (last->a->type >= AST_IDENTIFIER && last->a->type < STM_BLOCK)
last->a = STM1(RETURN, last->a);
}
return p;
}