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jsparse.c
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jsparse.c
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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sw=4 et tw=78:
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* JS parser.
*
* This is a recursive-descent parser for the JavaScript language specified by
* "The JavaScript 1.5 Language Specification". It uses lexical and semantic
* feedback to disambiguate non-LL(1) structures. It generates trees of nodes
* induced by the recursive parsing (not precise syntax trees, see jsparse.h).
* After tree construction, it rewrites trees to fold constants and evaluate
* compile-time expressions. Finally, it calls js_EmitTree (see jsemit.h) to
* generate bytecode.
*
* This parser attempts no error recovery.
*/
#include "jsstddef.h"
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "jstypes.h"
#include "jsarena.h" /* Added by JSIFY */
#include "jsutil.h" /* Added by JSIFY */
#include "jsapi.h"
#include "jsarray.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsconfig.h"
#include "jsemit.h"
#include "jsfun.h"
#include "jsinterp.h"
#include "jslock.h"
#include "jsnum.h"
#include "jsobj.h"
#include "jsopcode.h"
#include "jsparse.h"
#include "jsscan.h"
#include "jsscope.h"
#include "jsscript.h"
#include "jsstr.h"
#if JS_HAS_XML_SUPPORT
#include "jsxml.h"
#endif
#if JS_HAS_DESTRUCTURING
#include "jsdhash.h"
#endif
/*
* JS parsers, from lowest to highest precedence.
*
* Each parser takes a context, a token stream, and a tree context struct.
* Each returns a parse node tree or null on error.
*/
typedef JSParseNode *
JSParser(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc);
typedef JSParseNode *
JSMemberParser(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc,
JSBool allowCallSyntax);
typedef JSParseNode *
JSPrimaryParser(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc,
JSTokenType tt, JSBool afterDot);
static JSParser FunctionStmt;
static JSParser FunctionExpr;
static JSParser Statements;
static JSParser Statement;
static JSParser Variables;
static JSParser Expr;
static JSParser AssignExpr;
static JSParser CondExpr;
static JSParser OrExpr;
static JSParser AndExpr;
static JSParser BitOrExpr;
static JSParser BitXorExpr;
static JSParser BitAndExpr;
static JSParser EqExpr;
static JSParser RelExpr;
static JSParser ShiftExpr;
static JSParser AddExpr;
static JSParser MulExpr;
static JSParser UnaryExpr;
static JSMemberParser MemberExpr;
static JSPrimaryParser PrimaryExpr;
/*
* Insist that the next token be of type tt, or report errno and return null.
* NB: this macro uses cx and ts from its lexical environment.
*/
#define MUST_MATCH_TOKEN(tt, errno) \
JS_BEGIN_MACRO \
if (js_GetToken(cx, ts) != tt) { \
js_ReportCompileErrorNumber(cx, ts, JSREPORT_TS | JSREPORT_ERROR, \
errno); \
return NULL; \
} \
JS_END_MACRO
#define CHECK_RECURSION() \
JS_BEGIN_MACRO \
int stackDummy; \
if (!JS_CHECK_STACK_SIZE(cx, stackDummy)) { \
js_ReportCompileErrorNumber(cx, ts, JSREPORT_TS | JSREPORT_ERROR, \
JSMSG_OVER_RECURSED); \
return NULL; \
} \
JS_END_MACRO
#ifdef METER_PARSENODES
static uint32 parsenodes = 0;
static uint32 maxparsenodes = 0;
static uint32 recyclednodes = 0;
#endif
static JSParseNode *
RecycleTree(JSParseNode *pn, JSTreeContext *tc)
{
JSParseNode *next;
if (!pn)
return NULL;
JS_ASSERT(pn != tc->nodeList); /* catch back-to-back dup recycles */
next = pn->pn_next;
pn->pn_next = tc->nodeList;
tc->nodeList = pn;
#ifdef METER_PARSENODES
recyclednodes++;
#endif
return next;
}
static JSParseNode *
NewOrRecycledNode(JSContext *cx, JSTreeContext *tc)
{
JSParseNode *pn;
pn = tc->nodeList;
if (!pn) {
JS_ARENA_ALLOCATE_TYPE(pn, JSParseNode, &cx->tempPool);
if (!pn)
JS_ReportOutOfMemory(cx);
} else {
tc->nodeList = pn->pn_next;
/* Recycle immediate descendents only, to save work and working set. */
switch (pn->pn_arity) {
case PN_FUNC:
RecycleTree(pn->pn_body, tc);
break;
case PN_LIST:
if (pn->pn_head) {
/* XXX check for dup recycles in the list */
*pn->pn_tail = tc->nodeList;
tc->nodeList = pn->pn_head;
#ifdef METER_PARSENODES
recyclednodes += pn->pn_count;
#endif
}
break;
case PN_TERNARY:
RecycleTree(pn->pn_kid1, tc);
RecycleTree(pn->pn_kid2, tc);
RecycleTree(pn->pn_kid3, tc);
break;
case PN_BINARY:
RecycleTree(pn->pn_left, tc);
RecycleTree(pn->pn_right, tc);
break;
case PN_UNARY:
RecycleTree(pn->pn_kid, tc);
break;
case PN_NAME:
RecycleTree(pn->pn_expr, tc);
break;
case PN_NULLARY:
break;
}
}
#ifdef METER_PARSENODES
if (pn) {
parsenodes++;
if (parsenodes - recyclednodes > maxparsenodes)
maxparsenodes = parsenodes - recyclednodes;
}
#endif
return pn;
}
/*
* Allocate a JSParseNode from cx's temporary arena.
*/
static JSParseNode *
NewParseNode(JSContext *cx, JSTokenStream *ts, JSParseNodeArity arity,
JSTreeContext *tc)
{
JSParseNode *pn;
JSToken *tp;
pn = NewOrRecycledNode(cx, tc);
if (!pn)
return NULL;
tp = &CURRENT_TOKEN(ts);
pn->pn_type = tp->type;
pn->pn_pos = tp->pos;
pn->pn_op = JSOP_NOP;
pn->pn_arity = arity;
pn->pn_next = NULL;
pn->pn_ts = ts;
pn->pn_source = NULL;
return pn;
}
static JSParseNode *
NewBinary(JSContext *cx, JSTokenType tt,
JSOp op, JSParseNode *left, JSParseNode *right,
JSTreeContext *tc)
{
JSParseNode *pn, *pn1, *pn2;
if (!left || !right)
return NULL;
/*
* Flatten a left-associative (left-heavy) tree of a given operator into
* a list, to reduce js_FoldConstants and js_EmitTree recursion.
*/
if (left->pn_type == tt &&
left->pn_op == op &&
(js_CodeSpec[op].format & JOF_LEFTASSOC)) {
if (left->pn_arity != PN_LIST) {
pn1 = left->pn_left, pn2 = left->pn_right;
left->pn_arity = PN_LIST;
PN_INIT_LIST_1(left, pn1);
PN_APPEND(left, pn2);
if (tt == TOK_PLUS) {
if (pn1->pn_type == TOK_STRING)
left->pn_extra |= PNX_STRCAT;
else if (pn1->pn_type != TOK_NUMBER)
left->pn_extra |= PNX_CANTFOLD;
if (pn2->pn_type == TOK_STRING)
left->pn_extra |= PNX_STRCAT;
else if (pn2->pn_type != TOK_NUMBER)
left->pn_extra |= PNX_CANTFOLD;
}
}
PN_APPEND(left, right);
left->pn_pos.end = right->pn_pos.end;
if (tt == TOK_PLUS) {
if (right->pn_type == TOK_STRING)
left->pn_extra |= PNX_STRCAT;
else if (right->pn_type != TOK_NUMBER)
left->pn_extra |= PNX_CANTFOLD;
}
return left;
}
/*
* Fold constant addition immediately, to conserve node space and, what's
* more, so js_FoldConstants never sees mixed addition and concatenation
* operations with more than one leading non-string operand in a PN_LIST
* generated for expressions such as 1 + 2 + "pt" (which should evaluate
* to "3pt", not "12pt").
*/
if (tt == TOK_PLUS &&
left->pn_type == TOK_NUMBER &&
right->pn_type == TOK_NUMBER) {
left->pn_dval += right->pn_dval;
left->pn_pos.end = right->pn_pos.end;
RecycleTree(right, tc);
return left;
}
pn = NewOrRecycledNode(cx, tc);
if (!pn)
return NULL;
pn->pn_type = tt;
pn->pn_pos.begin = left->pn_pos.begin;
pn->pn_pos.end = right->pn_pos.end;
pn->pn_op = op;
pn->pn_arity = PN_BINARY;
pn->pn_left = left;
pn->pn_right = right;
pn->pn_next = NULL;
pn->pn_ts = NULL;
pn->pn_source = NULL;
return pn;
}
#if JS_HAS_GETTER_SETTER
static JSTokenType
CheckGetterOrSetter(JSContext *cx, JSTokenStream *ts, JSTokenType tt)
{
JSAtom *atom;
JSRuntime *rt;
JSOp op;
const char *name;
JS_ASSERT(CURRENT_TOKEN(ts).type == TOK_NAME);
atom = CURRENT_TOKEN(ts).t_atom;
rt = cx->runtime;
if (atom == rt->atomState.getterAtom)
op = JSOP_GETTER;
else if (atom == rt->atomState.setterAtom)
op = JSOP_SETTER;
else
return TOK_NAME;
if (js_PeekTokenSameLine(cx, ts) != tt)
return TOK_NAME;
(void) js_GetToken(cx, ts);
if (CURRENT_TOKEN(ts).t_op != JSOP_NOP) {
js_ReportCompileErrorNumber(cx, ts, JSREPORT_TS | JSREPORT_ERROR,
JSMSG_BAD_GETTER_OR_SETTER,
(op == JSOP_GETTER)
? js_getter_str
: js_setter_str);
return TOK_ERROR;
}
CURRENT_TOKEN(ts).t_op = op;
if (JS_HAS_STRICT_OPTION(cx)) {
name = js_AtomToPrintableString(cx, atom);
if (!name ||
!js_ReportCompileErrorNumber(cx, ts,
JSREPORT_TS |
JSREPORT_WARNING |
JSREPORT_STRICT,
JSMSG_DEPRECATED_USAGE,
name)) {
return TOK_ERROR;
}
}
return tt;
}
#endif
static void
MaybeSetupFrame(JSContext *cx, JSObject *chain, JSStackFrame *oldfp,
JSStackFrame *newfp)
{
/*
* Always push a new frame if the current frame is special, so that
* Variables gets the correct variables object: the one from the special
* frame's caller.
*/
if (oldfp &&
oldfp->varobj &&
oldfp->scopeChain == chain &&
!(oldfp->flags & JSFRAME_SPECIAL)) {
return;
}
memset(newfp, 0, sizeof *newfp);
/* Default to sharing the same variables object and scope chain. */
newfp->varobj = newfp->scopeChain = chain;
if (cx->options & JSOPTION_VAROBJFIX) {
while ((chain = JS_GetParent(cx, chain)) != NULL)
newfp->varobj = chain;
}
newfp->down = oldfp;
if (oldfp) {
/*
* In the case of eval and debugger frames, we need to dig down and find
* the real variables objects and function that our new stack frame is
* going to use.
*/
newfp->flags = oldfp->flags & (JSFRAME_SPECIAL | JSFRAME_COMPILE_N_GO |
JSFRAME_SCRIPT_OBJECT);
while (oldfp->flags & JSFRAME_SPECIAL) {
oldfp = oldfp->down;
if (!oldfp)
break;
}
if (oldfp && (newfp->flags & JSFRAME_SPECIAL)) {
newfp->varobj = oldfp->varobj;
newfp->vars = oldfp->vars;
newfp->fun = oldfp->fun;
}
}
cx->fp = newfp;
}
/*
* Parse a top-level JS script.
*/
JS_FRIEND_API(JSParseNode *)
js_ParseTokenStream(JSContext *cx, JSObject *chain, JSTokenStream *ts)
{
JSStackFrame *fp, frame;
JSTreeContext tc;
JSParseNode *pn;
/*
* Push a compiler frame if we have no frames, or if the top frame is a
* lightweight function activation, or if its scope chain doesn't match
* the one passed to us.
*/
fp = cx->fp;
MaybeSetupFrame(cx, chain, fp, &frame);
/*
* Protect atoms from being collected by a GC activation, which might
* - nest on this thread due to out of memory (the so-called "last ditch"
* GC attempted within js_NewGCThing), or
* - run for any reason on another thread if this thread is suspended on
* an object lock before it finishes generating bytecode into a script
* protected from the GC by a root or a stack frame reference.
*/
JS_KEEP_ATOMS(cx->runtime);
TREE_CONTEXT_INIT(&tc);
pn = Statements(cx, ts, &tc);
if (pn) {
if (!js_MatchToken(cx, ts, TOK_EOF)) {
js_ReportCompileErrorNumber(cx, ts, JSREPORT_TS | JSREPORT_ERROR,
JSMSG_SYNTAX_ERROR);
pn = NULL;
} else {
pn->pn_type = TOK_LC;
if (!js_FoldConstants(cx, pn, &tc))
pn = NULL;
}
}
TREE_CONTEXT_FINISH(&tc);
JS_UNKEEP_ATOMS(cx->runtime);
cx->fp = fp;
return pn;
}
/*
* Compile a top-level script.
*/
JS_FRIEND_API(JSBool)
js_CompileTokenStream(JSContext *cx, JSObject *chain, JSTokenStream *ts,
JSCodeGenerator *cg)
{
JSStackFrame *fp, frame;
uint32 flags;
JSParseNode *pn;
JSBool ok;
#ifdef METER_PARSENODES
void *sbrk(ptrdiff_t), *before = sbrk(0);
#endif
/*
* Push a compiler frame if we have no frames, or if the top frame is a
* lightweight function activation, or if its scope chain doesn't match
* the one passed to us.
*/
fp = cx->fp;
MaybeSetupFrame(cx, chain, fp, &frame);
flags = cx->fp->flags;
cx->fp->flags = flags |
(JS_HAS_COMPILE_N_GO_OPTION(cx)
? JSFRAME_COMPILING | JSFRAME_COMPILE_N_GO
: JSFRAME_COMPILING);
/* Prevent GC activation while compiling. */
JS_KEEP_ATOMS(cx->runtime);
pn = Statements(cx, ts, &cg->treeContext);
if (!pn) {
ok = JS_FALSE;
} else if (!js_MatchToken(cx, ts, TOK_EOF)) {
js_ReportCompileErrorNumber(cx, ts, JSREPORT_TS | JSREPORT_ERROR,
JSMSG_SYNTAX_ERROR);
ok = JS_FALSE;
} else {
#ifdef METER_PARSENODES
printf("Parser growth: %d (%u nodes, %u max, %u unrecycled)\n",
(char *)sbrk(0) - (char *)before,
parsenodes,
maxparsenodes,
parsenodes - recyclednodes);
before = sbrk(0);
#endif
/*
* No need to emit bytecode here -- Statements already has, for each
* statement in turn. Search for TCF_COMPILING in Statements, below.
* That flag is set for every tc == &cg->treeContext, and it implies
* that the tc can be downcast to a cg and used to emit code during
* parsing, rather than at the end of the parse phase.
*
* Nowadays the threaded interpreter needs a stop instruction, so we
* do have to emit that here.
*/
JS_ASSERT(cg->treeContext.flags & TCF_COMPILING);
ok = js_Emit1(cx, cg, JSOP_STOP) >= 0;
}
#ifdef METER_PARSENODES
printf("Code-gen growth: %d (%u bytecodes, %u srcnotes)\n",
(char *)sbrk(0) - (char *)before, CG_OFFSET(cg), cg->noteCount);
#endif
#ifdef JS_ARENAMETER
JS_DumpArenaStats(stdout);
#endif
JS_UNKEEP_ATOMS(cx->runtime);
cx->fp->flags = flags;
cx->fp = fp;
return ok;
}
/*
* Insist on a final return before control flows out of pn. Try to be a bit
* smart about loops: do {...; return e2;} while(0) at the end of a function
* that contains an early return e1 will get a strict warning. Similarly for
* iloops: while (true){...} is treated as though ... returns.
*/
#define ENDS_IN_OTHER 0
#define ENDS_IN_RETURN 1
#define ENDS_IN_BREAK 2
static int
HasFinalReturn(JSParseNode *pn)
{
JSParseNode *pn2, *pn3;
uintN rv, rv2, hasDefault;
switch (pn->pn_type) {
case TOK_LC:
if (!pn->pn_head)
return ENDS_IN_OTHER;
return HasFinalReturn(PN_LAST(pn));
case TOK_IF:
if (!pn->pn_kid3)
return ENDS_IN_OTHER;
return HasFinalReturn(pn->pn_kid2) & HasFinalReturn(pn->pn_kid3);
case TOK_WHILE:
pn2 = pn->pn_left;
if (pn2->pn_type == TOK_PRIMARY && pn2->pn_op == JSOP_TRUE)
return ENDS_IN_RETURN;
if (pn2->pn_type == TOK_NUMBER && pn2->pn_dval)
return ENDS_IN_RETURN;
return ENDS_IN_OTHER;
case TOK_DO:
pn2 = pn->pn_right;
if (pn2->pn_type == TOK_PRIMARY) {
if (pn2->pn_op == JSOP_FALSE)
return HasFinalReturn(pn->pn_left);
if (pn2->pn_op == JSOP_TRUE)
return ENDS_IN_RETURN;
}
if (pn2->pn_type == TOK_NUMBER) {
if (pn2->pn_dval == 0)
return HasFinalReturn(pn->pn_left);
return ENDS_IN_RETURN;
}
return ENDS_IN_OTHER;
case TOK_FOR:
pn2 = pn->pn_left;
if (pn2->pn_arity == PN_TERNARY && !pn2->pn_kid2)
return ENDS_IN_RETURN;
return ENDS_IN_OTHER;
case TOK_SWITCH:
rv = ENDS_IN_RETURN;
hasDefault = ENDS_IN_OTHER;
pn2 = pn->pn_right;
if (pn2->pn_type == TOK_LEXICALSCOPE)
pn2 = pn2->pn_expr;
for (pn2 = pn2->pn_head; rv && pn2; pn2 = pn2->pn_next) {
if (pn2->pn_type == TOK_DEFAULT)
hasDefault = ENDS_IN_RETURN;
pn3 = pn2->pn_right;
JS_ASSERT(pn3->pn_type == TOK_LC);
if (pn3->pn_head) {
rv2 = HasFinalReturn(PN_LAST(pn3));
if (rv2 == ENDS_IN_OTHER && pn2->pn_next)
/* Falling through to next case or default. */;
else
rv &= rv2;
}
}
/* If a final switch has no default case, we judge it harshly. */
rv &= hasDefault;
return rv;
case TOK_BREAK:
return ENDS_IN_BREAK;
case TOK_WITH:
return HasFinalReturn(pn->pn_right);
case TOK_RETURN:
return ENDS_IN_RETURN;
case TOK_COLON:
case TOK_LEXICALSCOPE:
return HasFinalReturn(pn->pn_expr);
case TOK_THROW:
return ENDS_IN_RETURN;
case TOK_TRY:
/* If we have a finally block that returns, we are done. */
if (pn->pn_kid3) {
rv = HasFinalReturn(pn->pn_kid3);
if (rv == ENDS_IN_RETURN)
return rv;
}
/* Else check the try block and any and all catch statements. */
rv = HasFinalReturn(pn->pn_kid1);
if (pn->pn_kid2) {
JS_ASSERT(pn->pn_kid2->pn_arity == PN_LIST);
for (pn2 = pn->pn_kid2->pn_head; pn2; pn2 = pn2->pn_next)
rv &= HasFinalReturn(pn2);
}
return rv;
case TOK_CATCH:
/* Check this catch block's body. */
return HasFinalReturn(pn->pn_kid3);
case TOK_LET:
/* Non-binary let statements are let declarations. */
if (pn->pn_arity != PN_BINARY)
return ENDS_IN_OTHER;
return HasFinalReturn(pn->pn_right);
default:
return ENDS_IN_OTHER;
}
}
static JSBool
ReportBadReturn(JSContext *cx, JSTokenStream *ts, uintN flags, uintN errnum,
uintN anonerrnum)
{
JSFunction *fun;
const char *name;
fun = cx->fp->fun;
if (fun->atom) {
name = js_AtomToPrintableString(cx, fun->atom);
} else {
errnum = anonerrnum;
name = NULL;
}
return js_ReportCompileErrorNumber(cx, ts, JSREPORT_TS | flags, errnum,
name);
}
static JSBool
CheckFinalReturn(JSContext *cx, JSTokenStream *ts, JSParseNode *pn)
{
return HasFinalReturn(pn) == ENDS_IN_RETURN ||
ReportBadReturn(cx, ts, JSREPORT_WARNING | JSREPORT_STRICT,
JSMSG_NO_RETURN_VALUE, JSMSG_ANON_NO_RETURN_VALUE);
}
static JSParseNode *
FunctionBody(JSContext *cx, JSTokenStream *ts, JSFunction *fun,
JSTreeContext *tc)
{
JSStackFrame *fp, frame;
JSObject *funobj;
JSStmtInfo stmtInfo;
uintN oldflags, firstLine;
JSParseNode *pn;
fp = cx->fp;
funobj = fun->object;
if (!fp || fp->fun != fun || fp->varobj != funobj ||
fp->scopeChain != funobj) {
memset(&frame, 0, sizeof frame);
frame.fun = fun;
frame.varobj = frame.scopeChain = funobj;
frame.down = fp;
if (fp)
frame.flags = fp->flags & JSFRAME_COMPILE_N_GO;
cx->fp = &frame;
}
/*
* Set interpreted early so js_EmitTree can test it to decide whether to
* eliminate useless expressions.
*/
fun->flags |= JSFUN_INTERPRETED;
js_PushStatement(tc, &stmtInfo, STMT_BLOCK, -1);
stmtInfo.flags = SIF_BODY_BLOCK;
oldflags = tc->flags;
tc->flags &= ~(TCF_RETURN_EXPR | TCF_RETURN_VOID);
tc->flags |= TCF_IN_FUNCTION;
/*
* Save the body's first line, and store it in pn->pn_pos.begin.lineno
* later, because we may have not peeked in ts yet, so Statements won't
* acquire a valid pn->pn_pos.begin from the current token.
*/
firstLine = ts->lineno;
pn = Statements(cx, ts, tc);
js_PopStatement(tc);
/* Check for falling off the end of a function that returns a value. */
if (pn && JS_HAS_STRICT_OPTION(cx) && (tc->flags & TCF_RETURN_EXPR)) {
if (!CheckFinalReturn(cx, ts, pn))
pn = NULL;
}
/*
* If we have a parse tree in pn and a code generator in tc, emit this
* function's code. We must do this here, not in js_CompileFunctionBody,
* in order to detect TCF_IN_FUNCTION among tc->flags.
*/
if (pn) {
pn->pn_pos.begin.lineno = firstLine;
if ((tc->flags & TCF_COMPILING)) {
JSCodeGenerator *cg = (JSCodeGenerator *) tc;
if (!js_FoldConstants(cx, pn, tc) ||
!js_EmitFunctionBytecode(cx, cg, pn)) {
pn = NULL;
}
}
}
cx->fp = fp;
tc->flags = oldflags | (tc->flags & (TCF_FUN_FLAGS | TCF_HAS_DEFXMLNS));
return pn;
}
/*
* Compile a JS function body, which might appear as the value of an event
* handler attribute in an HTML <INPUT> tag.
*/
JSBool
js_CompileFunctionBody(JSContext *cx, JSTokenStream *ts, JSFunction *fun)
{
JSArenaPool codePool, notePool;
JSCodeGenerator funcg;
JSStackFrame *fp, frame;
JSObject *funobj;
JSParseNode *pn;
JS_InitArenaPool(&codePool, "code", 1024, sizeof(jsbytecode));
JS_InitArenaPool(¬ePool, "note", 1024, sizeof(jssrcnote));
if (!js_InitCodeGenerator(cx, &funcg, &codePool, ¬ePool,
ts->filename, ts->lineno,
ts->principals)) {
return JS_FALSE;
}
/* Prevent GC activation while compiling. */
JS_KEEP_ATOMS(cx->runtime);
/* Push a JSStackFrame for use by FunctionBody. */
fp = cx->fp;
funobj = fun->object;
JS_ASSERT(!fp || (fp->fun != fun && fp->varobj != funobj &&
fp->scopeChain != funobj));
memset(&frame, 0, sizeof frame);
frame.fun = fun;
frame.varobj = frame.scopeChain = funobj;
frame.down = fp;
frame.flags = JS_HAS_COMPILE_N_GO_OPTION(cx)
? JSFRAME_COMPILING | JSFRAME_COMPILE_N_GO
: JSFRAME_COMPILING;
cx->fp = &frame;
/*
* Farble the body so that it looks like a block statement to js_EmitTree,
* which is called beneath FunctionBody; see Statements, further below in
* this file. FunctionBody pushes a STMT_BLOCK record around its call to
* Statements, so Statements will not compile each statement as it loops
* to save JSParseNode space -- it will not compile at all, only build a
* JSParseNode tree.
*
* Therefore we must fold constants, allocate try notes, and generate code
* for this function, including a stop opcode at the end.
*/
CURRENT_TOKEN(ts).type = TOK_LC;
pn = FunctionBody(cx, ts, fun, &funcg.treeContext);
if (pn && !js_NewScriptFromCG(cx, &funcg, fun))
pn = NULL;
/* Restore saved state and release code generation arenas. */
cx->fp = fp;
JS_UNKEEP_ATOMS(cx->runtime);
js_FinishCodeGenerator(cx, &funcg);
JS_FinishArenaPool(&codePool);
JS_FinishArenaPool(¬ePool);
return pn != NULL;
}
/*
* Parameter block types for the several Binder functions. We use a common
* helper function signature in order to share code among destructuring and
* simple variable declaration parsers. In the destructuring case, the binder
* function is called indirectly from the variable declaration parser by way
* of CheckDestructuring and its friends.
*/
typedef struct BindData BindData;
typedef JSBool
(*Binder)(JSContext *cx, BindData *data, JSAtom *atom, JSTreeContext *tc);
struct BindData {
JSParseNode *pn; /* error source coordinate */
JSTokenStream *ts; /* fallback if pn is null */
JSObject *obj; /* the variable object */
JSOp op; /* prolog bytecode or nop */
Binder binder; /* binder, discriminates u */
union {
struct {
JSFunction *fun; /* must come first! see next */
} arg;
struct {
JSFunction *fun; /* this overlays u.arg.fun */
JSClass *clasp;
JSPropertyOp getter;
JSPropertyOp setter;
uintN attrs;
} var;
struct {
jsuint index;
uintN overflow;
} let;
} u;
};
/*
* Given BindData *data and JSREPORT_* flags, expand to the second and third
* actual parameters to js_ReportCompileErrorNumber. Prefer reporting via pn
* to reporting via ts, for better destructuring error pointers.
*/
#define BIND_DATA_REPORT_ARGS(data, flags) \
(data)->pn ? (void *)(data)->pn : (void *)(data)->ts, \
((data)->pn ? JSREPORT_PN : JSREPORT_TS) | (flags)
static JSBool
BumpFormalCount(JSContext *cx, JSFunction *fun)
{
if (fun->nargs == JS_BITMASK(16)) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_TOO_MANY_FUN_ARGS);
return JS_FALSE;
}
fun->nargs++;
return JS_TRUE;
}
static JSBool
BindArg(JSContext *cx, BindData *data, JSAtom *atom, JSTreeContext *tc)
{
JSObject *obj, *pobj;
JSProperty *prop;
JSBool ok;
uintN dupflag;
JSFunction *fun;
const char *name;
obj = data->obj;
ok = js_LookupHiddenProperty(cx, obj, ATOM_TO_JSID(atom), &pobj, &prop);
if (!ok)
return JS_FALSE;
dupflag = 0;
if (prop) {
JS_ASSERT(pobj == obj);
name = js_AtomToPrintableString(cx, atom);
/*
* A duplicate parameter name, a "feature" required by ECMA-262.
* We force a duplicate node on the SCOPE_LAST_PROP(scope) list
* with the same id, distinguished by the SPROP_IS_DUPLICATE flag,
* and not mapped by an entry in scope.
*/
ok = name &&
js_ReportCompileErrorNumber(cx,
BIND_DATA_REPORT_ARGS(data,
JSREPORT_WARNING |
JSREPORT_STRICT),
JSMSG_DUPLICATE_FORMAL,
name);
OBJ_DROP_PROPERTY(cx, pobj, prop);
if (!ok)
return JS_FALSE;
dupflag = SPROP_IS_DUPLICATE;
}
fun = data->u.arg.fun;
if (!js_AddHiddenProperty(cx, data->obj, ATOM_TO_JSID(atom),
js_GetArgument, js_SetArgument,
SPROP_INVALID_SLOT,
JSPROP_PERMANENT | JSPROP_SHARED,
dupflag | SPROP_HAS_SHORTID,
fun->nargs)) {
return JS_FALSE;
}
return BumpFormalCount(cx, fun);
}
static JSBool
BindLocalVariable(JSContext *cx, BindData *data, JSAtom *atom)
{
JSFunction *fun;
/*
* Can't increase fun->nvars in an active frame, so insist that getter is
* js_GetLocalVariable, not js_GetCallVariable or anything else.
*/
if (data->u.var.getter != js_GetLocalVariable)
return JS_TRUE;
/*
* Don't bind a variable with the hidden name 'arguments', per ECMA-262.
* Instead 'var arguments' always restates the predefined property of the
* activation objects with unhidden name 'arguments'. Assignment to such
* a variable must be handled specially.
*/
if (atom == cx->runtime->atomState.argumentsAtom)
return JS_TRUE;
fun = data->u.var.fun;
if (!js_AddHiddenProperty(cx, data->obj, ATOM_TO_JSID(atom),
data->u.var.getter, data->u.var.setter,
SPROP_INVALID_SLOT,
data->u.var.attrs | JSPROP_SHARED,
SPROP_HAS_SHORTID, fun->u.i.nvars)) {
return JS_FALSE;
}
if (fun->u.i.nvars == JS_BITMASK(16)) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_TOO_MANY_FUN_VARS);
return JS_FALSE;
}
fun->u.i.nvars++;
return JS_TRUE;
}
#if JS_HAS_DESTRUCTURING
/*
* Forward declaration to maintain top-down presentation.
*/
static JSParseNode *
DestructuringExpr(JSContext *cx, BindData *data, JSTreeContext *tc,
JSTokenType tt);
static JSBool
BindDestructuringArg(JSContext *cx, BindData *data, JSAtom *atom,
JSTreeContext *tc)
{
JSAtomListElement *ale;
JSFunction *fun;
JSObject *obj, *pobj;
JSProperty *prop;
const char *name;