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tubestation/js/src/frontend/BytecodeCompiler.cpp

315 lines
11 KiB
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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=99:
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "frontend/BytecodeCompiler.h"
#include "jsprobes.h"
#include "frontend/BytecodeEmitter.h"
#include "frontend/FoldConstants.h"
#include "frontend/SemanticAnalysis.h"
#include "vm/GlobalObject.h"
#include "jsinferinlines.h"
#include "frontend/TreeContext-inl.h"
using namespace js;
using namespace js::frontend;
JSScript *
frontend::CompileScript(JSContext *cx, HandleObject scopeChain, StackFrame *callerFrame,
JSPrincipals *principals, JSPrincipals *originPrincipals,
bool compileAndGo, bool noScriptRval,
const jschar *chars, size_t length,
const char *filename, unsigned lineno, JSVersion version,
JSString *source_ /* = NULL */,
unsigned staticLevel /* = 0 */)
{
RootedString source(cx, source_);
class ProbesManager
{
const char* filename;
unsigned lineno;
public:
ProbesManager(const char *f, unsigned l) : filename(f), lineno(l) {
Probes::compileScriptBegin(filename, lineno);
}
~ProbesManager() { Probes::compileScriptEnd(filename, lineno); }
};
ProbesManager probesManager(filename, lineno);
/*
* The scripted callerFrame can only be given for compile-and-go scripts
* and non-zero static level requires callerFrame.
*/
JS_ASSERT_IF(callerFrame, compileAndGo);
JS_ASSERT_IF(staticLevel != 0, callerFrame);
Parser parser(cx, principals, originPrincipals, chars, length, filename, lineno, version,
/* foldConstants = */ true, compileAndGo);
if (!parser.init())
return NULL;
SharedContext sc(cx, scopeChain, /* fun = */ NULL, /* funbox = */ NULL, StrictModeFromContext(cx));
TreeContext tc(&parser, &sc, staticLevel, /* bodyid = */ 0);
if (!tc.init())
return NULL;
bool savedCallerFun = compileAndGo && callerFrame && callerFrame->isFunctionFrame();
Rooted<JSScript*> script(cx, JSScript::Create(cx,
/* enclosingScope = */ NullPtr(),
savedCallerFun,
principals,
originPrincipals,
compileAndGo,
noScriptRval,
version,
staticLevel));
if (!script)
return NULL;
// We can specialize a bit for the given scope chain if that scope chain is the global object.
JSObject *globalScope = scopeChain && scopeChain == &scopeChain->global() ? (JSObject*) scopeChain : NULL;
JS_ASSERT_IF(globalScope, globalScope->isNative());
JS_ASSERT_IF(globalScope, JSCLASS_HAS_GLOBAL_FLAG_AND_SLOTS(globalScope->getClass()));
BytecodeEmitter bce(/* parent = */ NULL, &parser, &sc, script, callerFrame, !!globalScope,
lineno);
if (!bce.init())
return NULL;
/* If this is a direct call to eval, inherit the caller's strictness. */
if (callerFrame && callerFrame->isScriptFrame() && callerFrame->script()->strictModeCode)
sc.strictModeState = StrictMode::STRICT;
if (compileAndGo) {
if (source) {
/*
* Save eval program source in script->atoms[0] for the
* eval cache (see EvalCacheLookup in jsobj.cpp).
*/
JSAtom *atom = js_AtomizeString(cx, source);
jsatomid _;
if (!atom || !bce.makeAtomIndex(atom, &_))
return NULL;
}
if (callerFrame && callerFrame->isFunctionFrame()) {
/*
* An eval script in a caller frame needs to have its enclosing
* function captured in case it refers to an upvar, and someone
* wishes to decompile it while it's running.
*/
ObjectBox *funbox = parser.newObjectBox(callerFrame->fun());
if (!funbox)
return NULL;
funbox->emitLink = bce.objectList.lastbox;
bce.objectList.lastbox = funbox;
bce.objectList.length++;
}
}
ParseNode *pn;
#if JS_HAS_XML_SUPPORT
pn = NULL;
bool onlyXML;
onlyXML = true;
#endif
TokenStream &tokenStream = parser.tokenStream;
{
ParseNode *stringsAtStart = ListNode::create(PNK_STATEMENTLIST, &parser);
if (!stringsAtStart)
return NULL;
stringsAtStart->makeEmpty();
bool ok = parser.processDirectives(stringsAtStart) && EmitTree(cx, &bce, stringsAtStart);
parser.freeTree(stringsAtStart);
if (!ok)
return NULL;
}
JS_ASSERT(sc.strictModeState != StrictMode::UNKNOWN);
for (;;) {
TokenKind tt = tokenStream.peekToken(TSF_OPERAND);
if (tt <= TOK_EOF) {
if (tt == TOK_EOF)
break;
JS_ASSERT(tt == TOK_ERROR);
return NULL;
}
pn = parser.statement();
if (!pn)
return NULL;
if (!FoldConstants(cx, pn, &parser))
return NULL;
if (!AnalyzeFunctions(&parser, callerFrame))
return NULL;
tc.functionList = NULL;
if (!EmitTree(cx, &bce, pn))
return NULL;
#if JS_HAS_XML_SUPPORT
if (!pn->isKind(PNK_SEMI) || !pn->pn_kid || !pn->pn_kid->isXMLItem())
onlyXML = false;
#endif
parser.freeTree(pn);
}
#if JS_HAS_XML_SUPPORT
/*
* Prevent XML data theft via <script src="http://victim.com/foo.xml">.
* For background, see:
*
* https://bugzilla.mozilla.org/show_bug.cgi?id=336551
*/
if (pn && onlyXML && !callerFrame) {
parser.reportError(NULL, JSMSG_XML_WHOLE_PROGRAM);
return NULL;
}
#endif
// It's an error to use |arguments| in a function that has a rest parameter.
if (callerFrame && callerFrame->isFunctionFrame() && callerFrame->fun()->hasRest()) {
PropertyName *arguments = cx->runtime->atomState.argumentsAtom;
for (AtomDefnRange r = tc.lexdeps->all(); !r.empty(); r.popFront()) {
if (r.front().key() == arguments) {
parser.reportError(NULL, JSMSG_ARGUMENTS_AND_REST);
return NULL;
}
}
// We're not in a function context, so we don't expect any bindings.
JS_ASSERT(!sc.bindings.hasBinding(cx, arguments));
}
/*
* Nowadays the threaded interpreter needs a stop instruction, so we
* do have to emit that here.
*/
if (Emit1(cx, &bce, JSOP_STOP) < 0)
return NULL;
if (!JSScript::fullyInitFromEmitter(cx, script, &bce))
return NULL;
bce.tellDebuggerAboutCompiledScript(cx);
return script;
}
// Compile a JS function body, which might appear as the value of an event
// handler attribute in an HTML <INPUT> tag, or in a Function() constructor.
bool
frontend::CompileFunctionBody(JSContext *cx, HandleFunction fun,
JSPrincipals *principals, JSPrincipals *originPrincipals,
Bindings *bindings, const jschar *chars, size_t length,
const char *filename, unsigned lineno, JSVersion version)
{
Parser parser(cx, principals, originPrincipals, chars, length, filename, lineno, version,
/* foldConstants = */ true, /* compileAndGo = */ false);
if (!parser.init())
return false;
JS_ASSERT(fun);
SharedContext funsc(cx, /* scopeChain = */ NULL, fun, /* funbox = */ NULL,
StrictModeFromContext(cx));
funsc.bindings.transfer(bindings);
fun->setArgCount(funsc.bindings.numArgs());
unsigned staticLevel = 0;
TreeContext funtc(&parser, &funsc, staticLevel, /* bodyid = */ 0);
if (!funtc.init())
return false;
Rooted<JSScript*> script(cx, JSScript::Create(cx,
/* enclosingScope = */ NullPtr(),
/* savedCallerFun = */ false,
principals,
originPrincipals,
/* compileAndGo = */ false,
/* noScriptRval = */ false,
version,
staticLevel));
if (!script)
return false;
StackFrame *nullCallerFrame = NULL;
BytecodeEmitter funbce(/* parent = */ NULL, &parser, &funsc, script, nullCallerFrame,
/* hasGlobalScope = */ false, lineno);
if (!funbce.init())
return false;
/* FIXME: make Function format the source for a function definition. */
ParseNode *fn = FunctionNode::create(PNK_NAME, &parser);
if (!fn)
return false;
fn->pn_body = NULL;
fn->pn_cookie.makeFree();
ParseNode *argsbody = ListNode::create(PNK_ARGSBODY, &parser);
if (!argsbody)
return false;
argsbody->setOp(JSOP_NOP);
argsbody->makeEmpty();
fn->pn_body = argsbody;
unsigned nargs = fun->nargs;
if (nargs) {
/*
* NB: do not use AutoLocalNameArray because it will release space
* allocated from cx->tempLifoAlloc by DefineArg.
*/
BindingVector names(cx);
if (!GetOrderedBindings(cx, funsc.bindings, &names))
return false;
for (unsigned i = 0; i < nargs; i++) {
if (!DefineArg(fn, names[i].maybeName, i, &parser))
return false;
}
}
/*
* After we're done parsing, we must fold constants, analyze any nested
* functions, and generate code for this function, including a stop opcode
* at the end.
*/
ParseNode *pn = parser.functionBody(Parser::StatementListBody);
if (!pn)
return false;
if (!parser.tokenStream.matchToken(TOK_EOF)) {
parser.reportError(NULL, JSMSG_SYNTAX_ERROR);
return false;
}
if (!FoldConstants(cx, pn, &parser))
return false;
if (!AnalyzeFunctions(&parser, nullCallerFrame))
return false;
if (fn->pn_body) {
JS_ASSERT(fn->pn_body->isKind(PNK_ARGSBODY));
fn->pn_body->append(pn);
fn->pn_body->pn_pos = pn->pn_pos;
pn = fn->pn_body;
}
if (!EmitFunctionScript(cx, &funbce, pn))
return false;
return true;
}