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tubestation/js/src/frontend/BytecodeCompiler.cpp

349 lines
11 KiB
C++

/* -*- 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;
bool
MarkInnerAndOuterFunctions(JSContext *cx, JSScript* script_)
{
Rooted<JSScript*> script(cx, script_);
Vector<JSScript *, 16> worklist(cx);
if (!worklist.append(script.reference()))
return false;
while (worklist.length()) {
JSScript *outer = worklist.back();
worklist.popBack();
if (outer->hasObjects()) {
ObjectArray *arr = outer->objects();
/*
* If this is an eval script, don't treat the saved caller function
* stored in the first object slot as an inner function.
*/
size_t start = outer->savedCallerFun ? 1 : 0;
for (size_t i = start; i < arr->length; i++) {
JSObject *obj = arr->vector[i];
if (!obj->isFunction())
continue;
JSFunction *fun = obj->toFunction();
JS_ASSERT(fun->isInterpreted());
JSScript *inner = fun->script();
if (outer->function() && outer->function()->isHeavyweight()) {
outer->isOuterFunction = true;
inner->isInnerFunction = true;
}
if (!inner->hasObjects())
continue;
if (!worklist.append(inner))
return false;
}
}
}
return true;
}
JSScript *
frontend::CompileScript(JSContext *cx, JSObject *scopeChain, StackFrame *callerFrame,
JSPrincipals *principals, JSPrincipals *originPrincipals,
bool compileAndGo, bool noScriptRval, bool needScriptGlobal,
const jschar *chars, size_t length,
const char *filename, unsigned lineno, JSVersion version,
JSString *source /* = NULL */,
unsigned staticLevel /* = 0 */)
{
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,
callerFrame, /* foldConstants = */ true, compileAndGo);
if (!parser.init())
return NULL;
SharedContext sc(cx, /* inFunction = */ false);
TreeContext tc(&parser, &sc);
if (!tc.init())
return NULL;
BytecodeEmitter bce(&parser, &sc, lineno, noScriptRval, needScriptGlobal);
if (!bce.init())
return NULL;
// We can specialize a bit for the given scope chain if that scope chain is the global object.
JSObject *globalObj = scopeChain && scopeChain == &scopeChain->global()
? &scopeChain->global()
: NULL;
JS_ASSERT_IF(globalObj, globalObj->isNative());
JS_ASSERT_IF(globalObj, JSCLASS_HAS_GLOBAL_FLAG_AND_SLOTS(globalObj->getClass()));
GlobalScope globalScope(cx, globalObj);
bce.sc->setScopeChain(scopeChain);
bce.globalScope = &globalScope;
if (!SetStaticLevel(bce.sc, staticLevel))
return NULL;
/* If this is a direct call to eval, inherit the caller's strictness. */
if (callerFrame && callerFrame->isScriptFrame() && callerFrame->script()->strictModeCode)
bce.sc->setInStrictMode();
#ifdef DEBUG
bool savedCallerFun;
savedCallerFun = false;
#endif
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++;
#ifdef DEBUG
savedCallerFun = true;
#endif
}
}
/*
* Inline this->statements to emit as we go to save AST space. We must
* generate our script-body blockid since we aren't calling Statements.
*/
uint32_t bodyid;
if (!GenerateBlockId(bce.sc, bodyid))
return NULL;
bce.sc->bodyid = bodyid;
ParseNode *pn;
#if JS_HAS_XML_SUPPORT
pn = NULL;
bool onlyXML;
onlyXML = true;
#endif
bool inDirectivePrologue = true;
TokenStream &tokenStream = parser.tokenStream;
tokenStream.setOctalCharacterEscape(false);
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 (inDirectivePrologue && !parser.recognizeDirectivePrologue(pn, &inDirectivePrologue))
return NULL;
if (!FoldConstants(cx, pn, bce.parser))
return NULL;
if (!AnalyzeFunctions(bce.parser))
return NULL;
bce.sc->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
bce.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.reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_XML_WHOLE_PROGRAM);
return NULL;
}
#endif
if (!parser.checkForArgumentsAndRest())
return NULL;
/*
* 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;
JS_ASSERT(bce.version() == version);
Rooted<JSScript*> script(cx);
script = JSScript::NewScriptFromEmitter(cx, &bce);
if (!script)
return NULL;
JS_ASSERT(script->savedCallerFun == savedCallerFun);
if (!MarkInnerAndOuterFunctions(cx, script))
return NULL;
return script;
}
/*
* Compile a JS function body, which might appear as the value of an event
* handler attribute in an HTML <INPUT> tag.
*/
bool
frontend::CompileFunctionBody(JSContext *cx, JSFunction *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,
/* cfp = */ NULL, /* foldConstants = */ true, /* compileAndGo = */ false);
if (!parser.init())
return false;
SharedContext funsc(cx, /* inFunction = */ true);
TreeContext funtc(&parser, &funsc);
if (!funtc.init())
return NULL;
BytecodeEmitter funbce(&parser, &funsc, lineno,
/* noScriptRval = */ false, /* needsScriptGlobal = */ false);
if (!funbce.init())
return false;
funsc.setFunction(fun);
funsc.bindings.transfer(cx, bindings);
fun->setArgCount(funsc.bindings.numArgs());
if (!GenerateBlockId(&funsc, funsc.bodyid))
return false;
/* FIXME: make Function format the source for a function definition. */
ParseNode *fn = FunctionNode::create(PNK_NAME, &parser);
if (fn) {
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.
*/
BindingNames names(cx);
if (!funsc.bindings.getLocalNameArray(cx, &names)) {
fn = NULL;
} else {
for (unsigned i = 0; i < nargs; i++) {
if (!DefineArg(fn, names[i].maybeAtom, i, &parser)) {
fn = NULL;
break;
}
}
}
}
}
/*
* 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 = fn ? parser.functionBody(Parser::StatementListBody) : NULL;
if (pn) {
if (!parser.tokenStream.matchToken(TOK_EOF)) {
parser.reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_SYNTAX_ERROR);
pn = NULL;
} else if (!FoldConstants(cx, pn, &parser)) {
/* FoldConstants reported the error already. */
pn = NULL;
} else if (!AnalyzeFunctions(&parser)) {
pn = NULL;
} else {
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))
pn = NULL;
}
}
return pn != NULL;
}