// Common code implementing direct and indirect eval.
//
// Evaluate call.argv[2], if it is a string, in the context of the given calling
// frame, with the provided scope chain, with the semantics of either a direct
// or indirect eval (see ES5 10.4.2). If this is an indirect eval, scopeobj
// must be a global object.
//
// On success, store the completion value in call.rval and return true.
static bool
EvalKernel(JSContext *cx, const CallArgs &args, EvalType evalType, AbstractFramePtr caller,
HandleObject scopeobj)
{
JS_ASSERT((evalType == INDIRECT_EVAL) == !caller);
JS_ASSERT_IF(evalType == INDIRECT_EVAL, scopeobj->isGlobal());
AssertInnerizedScopeChain(cx, *scopeobj);
Rooted<GlobalObject*> scopeObjGlobal(cx, &scopeobj->global());
if (!GlobalObject::isRuntimeCodeGenEnabled(cx, scopeObjGlobal)) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_CSP_BLOCKED_EVAL);
return false;
}
// ES5 15.1.2.1 step 1.
if (args.length() < 1) {
args.rval().setUndefined();
return true;
}
if (!args[0].isString()) {
args.rval().set(args[0]);
return true;
}
RootedString str(cx, args[0].toString());
// ES5 15.1.2.1 steps 2-8.
// Per ES5, indirect eval runs in the global scope. (eval is specified this
// way so that the compiler can make assumptions about what bindings may or
// may not exist in the current frame if it doesn't see 'eval'.)
unsigned staticLevel;
RootedValue thisv(cx);
if (evalType == DIRECT_EVAL) {
JS_ASSERT_IF(caller.isStackFrame(), !caller.asStackFrame()->runningInIon());
staticLevel = caller.script()->staticLevel + 1;
// Direct calls to eval are supposed to see the caller's |this|. If we
// haven't wrapped that yet, do so now, before we make a copy of it for
// the eval code to use.
if (!ComputeThis(cx, caller))
return false;
thisv = caller.thisValue();
} else {
JS_ASSERT(args.callee().global() == *scopeobj);
staticLevel = 0;
// Use the global as 'this', modulo outerization.
JSObject *thisobj = JSObject::thisObject(cx, scopeobj);
if (!thisobj)
return false;
thisv = ObjectValue(*thisobj);
}
Rooted<JSStableString*> stableStr(cx, str->ensureStable(cx));
if (!stableStr)
return false;
StableCharPtr chars = stableStr->chars();
size_t length = stableStr->length();
JSPrincipals *principals = PrincipalsForCompiledCode(args, cx);
JSScript *callerScript = caller ? caller.script() : NULL;
EvalJSONResult ejr = TryEvalJSON(cx, callerScript, chars, length, args.rval());
if (ejr != EvalJSON_NotJSON)
return ejr == EvalJSON_Success;
EvalScriptGuard esg(cx);
if (evalType == DIRECT_EVAL && caller.isNonEvalFunctionFrame())
esg.lookupInEvalCache(stableStr, caller.fun(), staticLevel);
if (!esg.foundScript()) {
unsigned lineno;
const char *filename;
JSPrincipals *originPrincipals;
CurrentScriptFileLineOrigin(cx, &filename, &lineno, &originPrincipals,
evalType == DIRECT_EVAL ? CALLED_FROM_JSOP_EVAL
: NOT_CALLED_FROM_JSOP_EVAL);
CompileOptions options(cx);
options.setFileAndLine(filename, lineno)
.setCompileAndGo(true)
.setNoScriptRval(false)
.setPrincipals(principals)
.setOriginPrincipals(originPrincipals);
RootedScript callerScript(cx, caller ? caller.script() : NULL);
UnrootedScript compiled = frontend::CompileScript(cx, scopeobj, callerScript, options,
chars.get(), length, stableStr, staticLevel);
if (!compiled)
return false;
esg.setNewScript(compiled);
}
return ExecuteKernel(cx, esg.script(), *scopeobj, thisv, ExecuteType(evalType),
NullFramePtr() /* evalInFrame */, args.rval().address());
}
// Common code implementing direct and indirect eval.
//
// Evaluate call.argv[2], if it is a string, in the context of the given calling
// frame, with the provided scope chain, with the semantics of either a direct
// or indirect eval (see ES5 10.4.2). If this is an indirect eval, scopeobj
// must be a global object.
//
// On success, store the completion value in call.rval and return true.
static bool
EvalKernel(JSContext *cx, const CallArgs &args, EvalType evalType, StackFrame *caller,
HandleObject scopeobj)
{
JS_ASSERT((evalType == INDIRECT_EVAL) == (caller == NULL));
JS_ASSERT_IF(evalType == INDIRECT_EVAL, scopeobj->isGlobal());
AssertInnerizedScopeChain(cx, *scopeobj);
if (!scopeobj->global().isRuntimeCodeGenEnabled(cx)) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_CSP_BLOCKED_EVAL);
return false;
}
// ES5 15.1.2.1 step 1.
if (args.length() < 1) {
args.rval().setUndefined();
return true;
}
if (!args[0].isString()) {
args.rval().set(args[0]);
return true;
}
JSString *str = args[0].toString();
// ES5 15.1.2.1 steps 2-8.
// Per ES5, indirect eval runs in the global scope. (eval is specified this
// way so that the compiler can make assumptions about what bindings may or
// may not exist in the current frame if it doesn't see 'eval'.)
unsigned staticLevel;
RootedValue thisv(cx);
if (evalType == DIRECT_EVAL) {
staticLevel = caller->script()->staticLevel + 1;
// Direct calls to eval are supposed to see the caller's |this|. If we
// haven't wrapped that yet, do so now, before we make a copy of it for
// the eval code to use.
if (!ComputeThis(cx, caller))
return false;
thisv = caller->thisValue();
} else {
JS_ASSERT(args.callee().global() == *scopeobj);
staticLevel = 0;
// Use the global as 'this', modulo outerization.
JSObject *thisobj = scopeobj->thisObject(cx);
if (!thisobj)
return false;
thisv = ObjectValue(*thisobj);
}
Rooted<JSLinearString*> linearStr(cx, str->ensureLinear(cx));
if (!linearStr)
return false;
const jschar *chars = linearStr->chars();
size_t length = linearStr->length();
SkipRoot skip(cx, &chars);
// If the eval string starts with '(' or '[' and ends with ')' or ']', it may be JSON.
// Try the JSON parser first because it's much faster. If the eval string
// isn't JSON, JSON parsing will probably fail quickly, so little time
// will be lost.
//
// Don't use the JSON parser if the caller is strict mode code, because in
// strict mode object literals must not have repeated properties, and the
// JSON parser cheerfully (and correctly) accepts them. If you're parsing
// JSON with eval and using strict mode, you deserve to be slow.
if (length > 2 &&
((chars[0] == '[' && chars[length - 1] == ']') ||
(chars[0] == '(' && chars[length - 1] == ')')) &&
(!caller || !caller->script()->strictModeCode))
{
// Remarkably, JavaScript syntax is not a superset of JSON syntax:
// strings in JavaScript cannot contain the Unicode line and paragraph
// terminator characters U+2028 and U+2029, but strings in JSON can.
// Rather than force the JSON parser to handle this quirk when used by
// eval, we simply don't use the JSON parser when either character
// appears in the provided string. See bug 657367.
for (const jschar *cp = &chars[1], *end = &chars[length - 2]; ; cp++) {
if (*cp == 0x2028 || *cp == 0x2029)
break;
if (cp == end) {
bool isArray = (chars[0] == '[');
JSONParser parser(cx, isArray ? chars : chars + 1, isArray ? length : length - 2,
JSONParser::StrictJSON, JSONParser::NoError);
RootedValue tmp(cx);
if (!parser.parse(&tmp))
return false;
if (tmp.isUndefined())
break;
args.rval().set(tmp);
return true;
}
}
}
EvalScriptGuard esg(cx);
JSPrincipals *principals = PrincipalsForCompiledCode(args, cx);
if (evalType == DIRECT_EVAL && caller->isNonEvalFunctionFrame())
esg.lookupInEvalCache(linearStr, caller->fun(), staticLevel);
if (!esg.foundScript()) {
unsigned lineno;
const char *filename;
JSPrincipals *originPrincipals;
CurrentScriptFileLineOrigin(cx, &filename, &lineno, &originPrincipals,
evalType == DIRECT_EVAL ? CALLED_FROM_JSOP_EVAL
: NOT_CALLED_FROM_JSOP_EVAL);
CompileOptions options(cx);
options.setFileAndLine(filename, lineno)
.setCompileAndGo(true)
.setNoScriptRval(false)
.setPrincipals(principals)
.setOriginPrincipals(originPrincipals);
JSScript *compiled = frontend::CompileScript(cx, scopeobj, caller, options,
chars, length, linearStr,
staticLevel);
if (!compiled)
return false;
esg.setNewScript(compiled);
}
return ExecuteKernel(cx, esg.script(), *scopeobj, thisv, ExecuteType(evalType),
NULL /* evalInFrame */, args.rval().address());
}