runtime/CommonSlowPaths.h

   1 /*
   2  * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef CommonSlowPaths_h
  27 #define CommonSlowPaths_h
  28
  29 #include "CodeBlock.h"
  30 #include "CodeSpecializationKind.h"
  31 #include "ExceptionHelpers.h"
  32 #include "JSArray.h"
  33 #include "NameInstance.h"
  34
  35 namespace JSC {
  36
  37 // The purpose of this namespace is to include slow paths that are shared
  38 // between the interpreter and baseline JIT. They are written to be agnostic
  39 // with respect to the slow-path calling convention, but they do rely on the
  40 // JS code being executed more-or-less directly from bytecode (so the call
  41 // frame layout is unmodified, making it potentially awkward to use these
  42 // from any optimizing JIT, like the DFG).
  43
  44 namespace CommonSlowPaths {
  45
  46 ALWAYS_INLINE ExecState* arityCheckFor(ExecState* exec, JSStack* stack, CodeSpecializationKind kind)
  47 {
  48     JSFunction* callee = jsCast<JSFunction*>(exec->callee());
  49     ASSERT(!callee->isHostFunction());
  50     CodeBlock* newCodeBlock = &callee->jsExecutable()->generatedBytecodeFor(kind);
  51     int argumentCountIncludingThis = exec->argumentCountIncludingThis();
  52
  53     // This ensures enough space for the worst case scenario of zero arguments passed by the caller.
  54     if (!stack->grow(exec->registers() + newCodeBlock->numParameters() + newCodeBlock->m_numCalleeRegisters))
  55         return 0;
  56
  57     ASSERT(argumentCountIncludingThis < newCodeBlock->numParameters());
  58
  59     // Too few arguments -- copy call frame and arguments, then fill in missing arguments with undefined.
  60     size_t delta = newCodeBlock->numParameters() - argumentCountIncludingThis;
  61     Register* src = exec->registers();
  62     Register* dst = exec->registers() + delta;
  63
  64     int i;
  65     int end = -ExecState::offsetFor(argumentCountIncludingThis);
  66     for (i = -1; i >= end; --i)
  67         dst[i] = src[i];
  68
  69     end -= delta;
  70     for ( ; i >= end; --i)
  71         dst[i] = jsUndefined();
  72
  73     ExecState* newExec = ExecState::create(dst);
  74     ASSERT((void*)newExec <= stack->end());
  75     return newExec;
  76 }
  77
  78 inline bool opIn(ExecState* exec, JSValue propName, JSValue baseVal)
  79 {
  80     if (!baseVal.isObject()) {
  81         exec->vm().exception = createInvalidParamError(exec, "in", baseVal);
  82         return false;
  83     }
  84
  85     JSObject* baseObj = asObject(baseVal);
  86
  87     uint32_t i;
  88     if (propName.getUInt32(i))
  89         return baseObj->hasProperty(exec, i);
  90
  91     if (isName(propName))
  92         return baseObj->hasProperty(exec, jsCast<NameInstance*>(propName.asCell())->privateName());
  93
  94     Identifier property(exec, propName.toString(exec)->value(exec));
  95     if (exec->vm().exception)
  96         return false;
  97     return baseObj->hasProperty(exec, property);
  98 }
  99
 100 } } // namespace JSC::CommonSlowPaths
 101
 102 #endif // CommonSlowPaths_h