BytecodeCompiler.cpp
/* -*- 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/NameFunctions.h"
#include "vm/GlobalObject.h"
#include "jsinferinlines.h"
#include "frontend/ParseMaps-inl.h"
#include "frontend/Parser-inl.h"
#include "frontend/SharedContext-inl.h"
using namespace js;
using namespace js::frontend;
static bool
CheckLength(JSContext *cx, size_t length)
{
// Note this limit is simply so we can store sourceStart and sourceEnd in
// JSScript as 32-bits. It could be lifted fairly easily, since the compiler
// is using size_t internally already.
if (length > UINT32_MAX) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_SOURCE_TOO_LONG);
return false;
}
return true;
}
static bool
SetSourceMap(JSContext *cx, TokenStream &tokenStream, ScriptSource *ss, JSScript *script)
{
if (tokenStream.hasSourceMap()) {
if (!ss->setSourceMap(cx, tokenStream.releaseSourceMap(), script->filename))
return false;
}
return true;
}
JSScript *
frontend::CompileScript(JSContext *cx, HandleObject scopeChain, StackFrame *callerFrame,
const CompileOptions &options,
const jschar *chars, size_t length,
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(options.filename, options.lineno);
/*
* The scripted callerFrame can only be given for compile-and-go scripts
* and non-zero static level requires callerFrame.
*/
JS_ASSERT_IF(callerFrame, options.compileAndGo);
JS_ASSERT_IF(staticLevel != 0, callerFrame);
if (!CheckLength(cx, length))
return NULL;
JS_ASSERT_IF(staticLevel != 0, options.sourcePolicy != CompileOptions::LAZY_SOURCE);
ScriptSource *ss = cx->new_<ScriptSource>();
if (!ss)
return NULL;
ScriptSourceHolder ssh(cx->runtime, ss);
SourceCompressionToken sct(cx);
switch (options.sourcePolicy) {
case CompileOptions::SAVE_SOURCE:
if (!ss->setSourceCopy(cx, chars, length, false, &sct))
return NULL;
break;
case CompileOptions::LAZY_SOURCE:
ss->setSourceRetrievable();
break;
case CompileOptions::NO_SOURCE:
break;
}
Parser parser(cx, options, chars, length, /* foldConstants = */ true);
if (!parser.init())
return NULL;
parser.sct = &sct;
GlobalSharedContext globalsc(cx, scopeChain, StrictModeFromContext(cx));
ParseContext pc(&parser, &globalsc, staticLevel, /* bodyid = */ 0);
if (!pc.init())
return NULL;
bool savedCallerFun = options.compileAndGo && callerFrame && callerFrame->isFunctionFrame();
Rooted<JSScript*> script(cx, JSScript::Create(cx, NullPtr(), savedCallerFun,
options, staticLevel, ss, 0, length));
if (!script)
return NULL;
// Global/eval script bindings are always empty (all names are added to the
// scope dynamically via JSOP_DEFFUN/VAR).
InternalHandle<Bindings*> bindings(script, &script->bindings);
if (!Bindings::initWithTemporaryStorage(cx, bindings, 0, 0, NULL))
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, &globalsc, script, callerFrame, !!globalScope,
options.lineno, options.selfHostingMode);
if (!bce.init())
return NULL;
/* If this is a direct call to eval, inherit the caller's strictness. */
if (callerFrame && callerFrame->script()->strictModeCode)
globalsc.strictModeState = StrictMode::STRICT;
if (options.compileAndGo) {
if (source) {
/*
* Save eval program source in script->atoms[0] for the
* eval cache (see EvalCacheLookup in jsobj.cpp).
*/
JSAtom *atom = 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.
*/
JSFunction *fun = callerFrame->fun();
ObjectBox *funbox = parser.newFunctionBox(fun, &pc,
fun->inStrictMode() ? StrictMode::STRICT
: StrictMode::NOTSTRICT);
if (!funbox)
return NULL;
bce.objectList.add(funbox);
}
}
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(globalsc.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 (!NameFunctions(cx, pn))
return 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 (!SetSourceMap(cx, tokenStream, ss, script))
return NULL;
#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()) {
HandlePropertyName arguments = cx->names().arguments;
for (AtomDefnRange r = pc.lexdeps->all(); !r.empty(); r.popFront()) {
if (r.front().key() == arguments) {
parser.reportError(NULL, JSMSG_ARGUMENTS_AND_REST);
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;
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, CompileOptions options,
const AutoNameVector &formals, const jschar *chars, size_t length)
{
if (!CheckLength(cx, length))
return false;
ScriptSource *ss = cx->new_<ScriptSource>();
if (!ss)
return false;
ScriptSourceHolder ssh(cx->runtime, ss);
SourceCompressionToken sct(cx);
JS_ASSERT(options.sourcePolicy != CompileOptions::LAZY_SOURCE);
if (options.sourcePolicy == CompileOptions::SAVE_SOURCE) {
if (!ss->setSourceCopy(cx, chars, length, true, &sct))
return false;
}
options.setCompileAndGo(false);
Parser parser(cx, options, chars, length, /* foldConstants = */ true);
if (!parser.init())
return false;
parser.sct = &sct;
JS_ASSERT(fun);
StrictMode sms = StrictModeFromContext(cx);
FunctionBox *funbox = parser.newFunctionBox(fun, /* outerpc = */ NULL, sms);
fun->setArgCount(formals.length());
unsigned staticLevel = 0;
ParseContext funpc(&parser, funbox, staticLevel, /* bodyid = */ 0);
if (!funpc.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;
for (unsigned i = 0; i < formals.length(); i++) {
if (!DefineArg(&parser, fn, formals[i]))
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;
Rooted<JSScript*> script(cx, JSScript::Create(cx, NullPtr(), false, options,
staticLevel, ss, 0, length));
if (!script)
return false;
InternalHandle<Bindings*> bindings(script, &script->bindings);
if (!funpc.generateFunctionBindings(cx, bindings))
return false;
BytecodeEmitter funbce(/* parent = */ NULL, &parser, funbox, script, /* callerFrame = */ NULL,
/* hasGlobalScope = */ false, options.lineno);
if (!funbce.init())
return false;
if (!NameFunctions(cx, pn))
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 (!SetSourceMap(cx, parser.tokenStream, ss, script))
return false;
if (!EmitFunctionScript(cx, &funbce, pn))
return false;
return true;
}