LCOV - code coverage report
Current view: directory - js/src/frontend - BytecodeCompiler.cpp (source / functions) Found Hit Coverage
Test: app.info Lines: 181 150 82.9 %
Date: 2012-06-02 Functions: 3 3 100.0 %

       1                 : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
       2                 :  * vim: set ts=8 sw=4 et tw=99:
       3                 :  *
       4                 :  * ***** BEGIN LICENSE BLOCK *****
       5                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       6                 :  *
       7                 :  * The contents of this file are subject to the Mozilla Public License Version
       8                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       9                 :  * the License. You may obtain a copy of the License at
      10                 :  * http://www.mozilla.org/MPL/
      11                 :  *
      12                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      13                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      14                 :  * for the specific language governing rights and limitations under the
      15                 :  * License.
      16                 :  *
      17                 :  * The Original Code is Mozilla Communicator client code, released
      18                 :  * March 31, 1998.
      19                 :  *
      20                 :  * The Initial Developer of the Original Code is
      21                 :  * Netscape Communications Corporation.
      22                 :  * Portions created by the Initial Developer are Copyright (C) 1998-2011
      23                 :  * the Initial Developer. All Rights Reserved.
      24                 :  *
      25                 :  * Contributor(s):
      26                 :  *
      27                 :  * Alternatively, the contents of this file may be used under the terms of
      28                 :  * either the GNU General Public License Version 2 or later (the "GPL"), or
      29                 :  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      30                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      31                 :  * of those above. If you wish to allow use of your version of this file only
      32                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      33                 :  * use your version of this file under the terms of the MPL, indicate your
      34                 :  * decision by deleting the provisions above and replace them with the notice
      35                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      36                 :  * the provisions above, a recipient may use your version of this file under
      37                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      38                 :  *
      39                 :  * ***** END LICENSE BLOCK ***** */
      40                 : 
      41                 : #include "frontend/BytecodeCompiler.h"
      42                 : 
      43                 : #include "jsprobes.h"
      44                 : 
      45                 : #include "frontend/BytecodeEmitter.h"
      46                 : #include "frontend/FoldConstants.h"
      47                 : #include "frontend/SemanticAnalysis.h"
      48                 : #include "vm/GlobalObject.h"
      49                 : 
      50                 : #include "jsinferinlines.h"
      51                 : 
      52                 : using namespace js;
      53                 : using namespace js::frontend;
      54                 : 
      55                 : bool
      56          120672 : DefineGlobals(JSContext *cx, GlobalScope &globalScope, JSScript *script)
      57                 : {
      58          120672 :     JSObject *globalObj = globalScope.globalObj;
      59                 : 
      60                 :     /* Define and update global properties. */
      61          188613 :     for (size_t i = 0; i < globalScope.defs.length(); i++) {
      62           67941 :         GlobalScope::GlobalDef &def = globalScope.defs[i];
      63                 : 
      64                 :         /* Names that could be resolved ahead of time can be skipped. */
      65           67941 :         if (!def.atom)
      66              39 :             continue;
      67                 : 
      68           67902 :         jsid id = ATOM_TO_JSID(def.atom);
      69                 :         Value rval;
      70                 : 
      71           67902 :         if (def.funbox) {
      72           22026 :             JSFunction *fun = def.funbox->function();
      73                 : 
      74                 :             /*
      75                 :              * No need to check for redeclarations or anything, global
      76                 :              * optimizations only take place if the property is not defined.
      77                 :              */
      78           22026 :             rval.setObject(*fun);
      79           22026 :             types::AddTypePropertyId(cx, globalObj, id, rval);
      80                 :         } else {
      81           45876 :             rval.setUndefined();
      82                 :         }
      83                 : 
      84                 :         /*
      85                 :          * Don't update the type information when defining the property for the
      86                 :          * global object, per the consistency rules for type properties. If the
      87                 :          * property is only undefined before it is ever written, we can check
      88                 :          * the global directly during compilation and avoid having to emit type
      89                 :          * checks every time it is accessed in the script.
      90                 :          */
      91                 :         const Shape *shape =
      92                 :             DefineNativeProperty(cx, globalObj, id, rval, JS_PropertyStub, JS_StrictPropertyStub,
      93           67902 :                                  JSPROP_ENUMERATE | JSPROP_PERMANENT, 0, 0, DNP_SKIP_TYPE);
      94           67902 :         if (!shape)
      95               0 :             return false;
      96           67902 :         def.knownSlot = shape->slot();
      97                 :     }
      98                 : 
      99          241344 :     Vector<JSScript *, 16> worklist(cx);
     100          120672 :     if (!worklist.append(script))
     101               0 :         return false;
     102                 : 
     103                 :     /*
     104                 :      * Recursively walk through all scripts we just compiled. For each script,
     105                 :      * go through all global uses. Each global use indexes into globalScope->defs.
     106                 :      * Use this information to repoint each use to the correct slot in the global
     107                 :      * object.
     108                 :      */
     109          664910 :     while (worklist.length()) {
     110          423566 :         JSScript *outer = worklist.back();
     111          423566 :         worklist.popBack();
     112                 : 
     113          423566 :         if (JSScript::isValidOffset(outer->objectsOffset)) {
     114          382186 :             JSObjectArray *arr = outer->objects();
     115                 : 
     116                 :             /*
     117                 :              * If this is an eval script, don't treat the saved caller function
     118                 :              * stored in the first object slot as an inner function.
     119                 :              */
     120          382186 :             size_t start = outer->savedCallerFun ? 1 : 0;
     121                 : 
     122         1765907 :             for (size_t i = start; i < arr->length; i++) {
     123         1383721 :                 JSObject *obj = arr->vector[i];
     124         1383721 :                 if (!obj->isFunction())
     125          405819 :                     continue;
     126          977902 :                 JSFunction *fun = obj->toFunction();
     127          977902 :                 JS_ASSERT(fun->isInterpreted());
     128          977902 :                 JSScript *inner = fun->script();
     129          977902 :                 if (outer->function() && outer->function()->isHeavyweight()) {
     130          134868 :                     outer->isOuterFunction = true;
     131          134868 :                     inner->isInnerFunction = true;
     132                 :                 }
     133         1954624 :                 if (!JSScript::isValidOffset(inner->globalsOffset) &&
     134          976722 :                     !JSScript::isValidOffset(inner->objectsOffset)) {
     135          675008 :                     continue;
     136                 :                 }
     137          302894 :                 if (!worklist.append(inner))
     138               0 :                     return false;
     139                 :             }
     140                 :         }
     141                 : 
     142          423566 :         if (!JSScript::isValidOffset(outer->globalsOffset))
     143          410767 :             continue;
     144                 : 
     145           12799 :         GlobalSlotArray *globalUses = outer->globals();
     146           12799 :         uint32_t nGlobalUses = globalUses->length;
     147           36527 :         for (uint32_t i = 0; i < nGlobalUses; i++) {
     148           23728 :             uint32_t index = globalUses->vector[i].slot;
     149           23728 :             JS_ASSERT(index < globalScope.defs.length());
     150           23728 :             globalUses->vector[i].slot = globalScope.defs[index].knownSlot;
     151                 :         }
     152                 :     }
     153                 : 
     154          120672 :     return true;
     155                 : }
     156                 : 
     157                 : JSScript *
     158          120957 : frontend::CompileScript(JSContext *cx, JSObject *scopeChain, StackFrame *callerFrame,
     159                 :                         JSPrincipals *principals, JSPrincipals *originPrincipals,
     160                 :                         uint32_t tcflags,
     161                 :                         const jschar *chars, size_t length,
     162                 :                         const char *filename, unsigned lineno, JSVersion version,
     163                 :                         JSString *source /* = NULL */,
     164                 :                         unsigned staticLevel /* = 0 */)
     165                 : {
     166                 :     TokenKind tt;
     167                 :     ParseNode *pn;
     168                 :     JSScript *script;
     169                 :     bool inDirectivePrologue;
     170                 : 
     171               0 :     JS_ASSERT(!(tcflags & ~(TCF_COMPILE_N_GO | TCF_NO_SCRIPT_RVAL | TCF_COMPILE_FOR_EVAL
     172          120957 :                             | TCF_NEED_SCRIPT_GLOBAL)));
     173                 : 
     174                 :     /*
     175                 :      * The scripted callerFrame can only be given for compile-and-go scripts
     176                 :      * and non-zero static level requires callerFrame.
     177                 :      */
     178          120957 :     JS_ASSERT_IF(callerFrame, tcflags & TCF_COMPILE_N_GO);
     179          120957 :     JS_ASSERT_IF(staticLevel != 0, callerFrame);
     180                 : 
     181          241914 :     Parser parser(cx, principals, originPrincipals, callerFrame);
     182          120957 :     if (!parser.init(chars, length, filename, lineno, version))
     183               0 :         return NULL;
     184                 : 
     185          120957 :     TokenStream &tokenStream = parser.tokenStream;
     186                 : 
     187          241914 :     BytecodeEmitter bce(&parser, tokenStream.getLineno());
     188          120957 :     if (!bce.init(cx, TreeContext::USED_AS_TREE_CONTEXT))
     189               0 :         return NULL;
     190                 : 
     191          120957 :     Probes::compileScriptBegin(cx, filename, lineno);
     192                 :     MUST_FLOW_THROUGH("out");
     193                 : 
     194                 :     // We can specialize a bit for the given scope chain if that scope chain is the global object.
     195          120957 :     JSObject *globalObj = scopeChain && scopeChain == &scopeChain->global()
     196                 :                           ? &scopeChain->global()
     197          241914 :                           : NULL;
     198                 : 
     199          120957 :     JS_ASSERT_IF(globalObj, globalObj->isNative());
     200          120957 :     JS_ASSERT_IF(globalObj, JSCLASS_HAS_GLOBAL_FLAG_AND_SLOTS(globalObj->getClass()));
     201                 : 
     202                 :     /* Null script early in case of error, to reduce our code footprint. */
     203          120957 :     script = NULL;
     204                 : 
     205          241914 :     GlobalScope globalScope(cx, globalObj, &bce);
     206          120957 :     bce.flags |= tcflags;
     207          120957 :     bce.setScopeChain(scopeChain);
     208          120957 :     bce.globalScope = &globalScope;
     209          120957 :     if (!SetStaticLevel(&bce, staticLevel))
     210               0 :         goto out;
     211                 : 
     212                 :     /* If this is a direct call to eval, inherit the caller's strictness.  */
     213          167823 :     if (callerFrame &&
     214           23433 :         callerFrame->isScriptFrame() &&
     215           23433 :         callerFrame->script()->strictModeCode) {
     216             659 :         bce.flags |= TCF_STRICT_MODE_CODE;
     217             659 :         tokenStream.setStrictMode();
     218                 :     }
     219                 : 
     220                 : #ifdef DEBUG
     221                 :     bool savedCallerFun;
     222          120957 :     savedCallerFun = false;
     223                 : #endif
     224          120957 :     if (tcflags & TCF_COMPILE_N_GO) {
     225          104305 :         if (source) {
     226                 :             /*
     227                 :              * Save eval program source in script->atoms[0] for the
     228                 :              * eval cache (see EvalCacheLookup in jsobj.cpp).
     229                 :              */
     230           34313 :             JSAtom *atom = js_AtomizeString(cx, source);
     231                 :             jsatomid _;
     232           34313 :             if (!atom || !bce.makeAtomIndex(atom, &_))
     233               0 :                 goto out;
     234                 :         }
     235                 : 
     236          104305 :         if (callerFrame && callerFrame->isFunctionFrame()) {
     237                 :             /*
     238                 :              * An eval script in a caller frame needs to have its enclosing
     239                 :              * function captured in case it refers to an upvar, and someone
     240                 :              * wishes to decompile it while it's running.
     241                 :              */
     242           21204 :             ObjectBox *funbox = parser.newObjectBox(callerFrame->fun());
     243           21204 :             if (!funbox)
     244               0 :                 goto out;
     245           21204 :             funbox->emitLink = bce.objectList.lastbox;
     246           21204 :             bce.objectList.lastbox = funbox;
     247           21204 :             bce.objectList.length++;
     248                 : #ifdef DEBUG
     249           21204 :             savedCallerFun = true;
     250                 : #endif
     251                 :         }
     252                 :     }
     253                 : 
     254                 :     /*
     255                 :      * Inline this->statements to emit as we go to save AST space. We must
     256                 :      * generate our script-body blockid since we aren't calling Statements.
     257                 :      */
     258                 :     uint32_t bodyid;
     259          120957 :     if (!GenerateBlockId(&bce, bodyid))
     260               0 :         goto out;
     261          120957 :     bce.bodyid = bodyid;
     262                 : 
     263                 : #if JS_HAS_XML_SUPPORT
     264          120957 :     pn = NULL;
     265                 :     bool onlyXML;
     266          120957 :     onlyXML = true;
     267                 : #endif
     268                 : 
     269          120957 :     inDirectivePrologue = true;
     270          120957 :     tokenStream.setOctalCharacterEscape(false);
     271          891367 :     for (;;) {
     272         1012324 :         tt = tokenStream.peekToken(TSF_OPERAND);
     273         1012324 :         if (tt <= TOK_EOF) {
     274          120681 :             if (tt == TOK_EOF)
     275                 :                 break;
     276               9 :             JS_ASSERT(tt == TOK_ERROR);
     277               9 :             goto out;
     278                 :         }
     279                 : 
     280          891643 :         pn = parser.statement();
     281          891643 :         if (!pn)
     282             276 :             goto out;
     283          891367 :         JS_ASSERT(!bce.blockNode);
     284                 : 
     285          891367 :         if (inDirectivePrologue && !parser.recognizeDirectivePrologue(pn, &inDirectivePrologue))
     286               0 :             goto out;
     287                 : 
     288          891367 :         if (!FoldConstants(cx, pn, &bce))
     289               0 :             goto out;
     290                 : 
     291          891367 :         if (!AnalyzeFunctions(&bce))
     292               0 :             goto out;
     293          891367 :         bce.functionList = NULL;
     294                 : 
     295          891367 :         if (!EmitTree(cx, &bce, pn))
     296               0 :             goto out;
     297                 : 
     298                 : #if JS_HAS_XML_SUPPORT
     299          891367 :         if (!pn->isKind(PNK_SEMI) || !pn->pn_kid || !pn->pn_kid->isXMLItem())
     300          891367 :             onlyXML = false;
     301                 : #endif
     302          891367 :         bce.freeTree(pn);
     303                 :     }
     304                 : 
     305                 : #if JS_HAS_XML_SUPPORT
     306                 :     /*
     307                 :      * Prevent XML data theft via <script src="http://victim.com/foo.xml">.
     308                 :      * For background, see:
     309                 :      *
     310                 :      * https://bugzilla.mozilla.org/show_bug.cgi?id=336551
     311                 :      */
     312          241041 :     if (pn && onlyXML && !callerFrame) {
     313               0 :         parser.reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_XML_WHOLE_PROGRAM);
     314               0 :         goto out;
     315                 :     }
     316                 : #endif
     317                 : 
     318                 :     /*
     319                 :      * Nowadays the threaded interpreter needs a stop instruction, so we
     320                 :      * do have to emit that here.
     321                 :      */
     322          120672 :     if (Emit1(cx, &bce, JSOP_STOP) < 0)
     323               0 :         goto out;
     324                 : 
     325          120672 :     JS_ASSERT(bce.version() == version);
     326                 : 
     327          120672 :     script = JSScript::NewScriptFromEmitter(cx, &bce);
     328          120672 :     if (!script)
     329               0 :         goto out;
     330                 : 
     331          120672 :     JS_ASSERT(script->savedCallerFun == savedCallerFun);
     332                 : 
     333          120672 :     if (!DefineGlobals(cx, globalScope, script))
     334               0 :         script = NULL;
     335                 : 
     336                 :   out:
     337          120957 :     Probes::compileScriptEnd(cx, script, filename, lineno);
     338          120957 :     return script;
     339                 : }
     340                 : 
     341                 : /*
     342                 :  * Compile a JS function body, which might appear as the value of an event
     343                 :  * handler attribute in an HTML <INPUT> tag.
     344                 :  */
     345                 : bool
     346           10413 : frontend::CompileFunctionBody(JSContext *cx, JSFunction *fun,
     347                 :                               JSPrincipals *principals, JSPrincipals *originPrincipals,
     348                 :                               Bindings *bindings, const jschar *chars, size_t length,
     349                 :                               const char *filename, unsigned lineno, JSVersion version)
     350                 : {
     351           20826 :     Parser parser(cx, principals, originPrincipals);
     352           10413 :     if (!parser.init(chars, length, filename, lineno, version))
     353               0 :         return false;
     354                 : 
     355           10413 :     TokenStream &tokenStream = parser.tokenStream;
     356                 : 
     357           20826 :     BytecodeEmitter funbce(&parser, tokenStream.getLineno());
     358           10413 :     if (!funbce.init(cx, TreeContext::USED_AS_TREE_CONTEXT))
     359               0 :         return false;
     360                 : 
     361           10413 :     funbce.flags |= TCF_IN_FUNCTION;
     362           10413 :     funbce.setFunction(fun);
     363           10413 :     funbce.bindings.transfer(cx, bindings);
     364           10413 :     fun->setArgCount(funbce.bindings.countArgs());
     365           10413 :     if (!GenerateBlockId(&funbce, funbce.bodyid))
     366               0 :         return false;
     367                 : 
     368                 :     /* FIXME: make Function format the source for a function definition. */
     369           10413 :     ParseNode *fn = FunctionNode::create(PNK_NAME, &funbce);
     370           10413 :     if (fn) {
     371           10413 :         fn->pn_body = NULL;
     372           10413 :         fn->pn_cookie.makeFree();
     373                 : 
     374           10413 :         unsigned nargs = fun->nargs;
     375           10413 :         if (nargs) {
     376                 :             /*
     377                 :              * NB: do not use AutoLocalNameArray because it will release space
     378                 :              * allocated from cx->tempLifoAlloc by DefineArg.
     379                 :              */
     380            9448 :             Vector<JSAtom *> names(cx);
     381            4724 :             if (!funbce.bindings.getLocalNameArray(cx, &names)) {
     382               0 :                 fn = NULL;
     383                 :             } else {
     384            9457 :                 for (unsigned i = 0; i < nargs; i++) {
     385            4733 :                     if (!DefineArg(fn, names[i], i, &funbce)) {
     386               0 :                         fn = NULL;
     387               0 :                         break;
     388                 :                     }
     389                 :                 }
     390                 :             }
     391                 :         }
     392                 :     }
     393                 : 
     394                 :     /*
     395                 :      * After we're done parsing, we must fold constants, analyze any nested
     396                 :      * functions, and generate code for this function, including a stop opcode
     397                 :      * at the end.
     398                 :      */
     399           10413 :     ParseNode *pn = fn ? parser.functionBody(Parser::StatementListBody) : NULL;
     400           10413 :     if (pn) {
     401           10105 :         if (!CheckStrictParameters(cx, &funbce)) {
     402               0 :             pn = NULL;
     403           10105 :         } else if (!tokenStream.matchToken(TOK_EOF)) {
     404               0 :             parser.reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_SYNTAX_ERROR);
     405               0 :             pn = NULL;
     406           10105 :         } else if (!FoldConstants(cx, pn, &funbce)) {
     407                 :             /* FoldConstants reported the error already. */
     408               0 :             pn = NULL;
     409           10105 :         } else if (!AnalyzeFunctions(&funbce)) {
     410               0 :             pn = NULL;
     411                 :         } else {
     412           10105 :             if (fn->pn_body) {
     413            4722 :                 JS_ASSERT(fn->pn_body->isKind(PNK_ARGSBODY));
     414            4722 :                 fn->pn_body->append(pn);
     415            4722 :                 fn->pn_body->pn_pos = pn->pn_pos;
     416            4722 :                 pn = fn->pn_body;
     417                 :             }
     418                 : 
     419           10105 :             if (!EmitFunctionScript(cx, &funbce, pn))
     420               0 :                 pn = NULL;
     421                 :         }
     422                 :     }
     423                 : 
     424           10413 :     return pn != NULL;
     425                 : }

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