2014-07-03 16:23:25 +04:00

560 lines
17 KiB
C

/* Copyright 2014 Samsung Electronics Co., Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "ctx-manager.h"
#include "ctx-reference.h"
#include "globals.h"
#include "ecma-alloc.h"
#include "ecma-globals.h"
#include "ecma-conversion.h"
#include "ecma-gc.h"
#include "ecma-helpers.h"
#include "jerry-libc.h"
#include "mem-poolman.h"
/** \addtogroup ctxman Context manager
* @{
*/
/**
* Maximum depth of varibles' context nestings stack.
*
* TODO: Move to configuration header.
*/
#define CTX_MAX_NUMBER_OF_VARIABLES_CONTEXTS 32
/**
* JerryScript needs at least one variables' context nesting.
*/
JERRY_STATIC_ASSERT( CTX_MAX_NUMBER_OF_VARIABLES_CONTEXTS >= 1 );
/**
* Description of a variables' context
*/
typedef struct
{
/**
* Pointer to object, associated with 'this' keyword.
*/
ecma_Object_t *pThisBinding;
/**
* Chain of lexical environments
*/
ecma_Object_t *pLexicalEnvironment;
} ctx_VariablesContext_t;
/**
* Stack of variables' contexts.
*/
static ctx_VariablesContext_t ctx_Stack[ CTX_MAX_NUMBER_OF_VARIABLES_CONTEXTS ];
/**
* Current nestings' stack depth.
*/
static size_t ctx_ContextsNumber = 0;
/**
* Current variables' context (context on the top of stack)
*/
#define ctx_CurrentContext ( ctx_Stack[ ctx_ContextsNumber - 1 ])
/**
* The global object
*/
ecma_Object_t* ctx_pGlobalObject;
/**
* Get ecma-value from variable
*
* @return value descriptor
*/
static ecma_Value_t
ctx_GetValueDescriptorFromVariable( ctx_SyntacticReference_t *pVar) /**< variable */
{
/*
* TODO:
*/
(void)pVar;
JERRY_UNIMPLEMENTED();
} /* ctx_GetValueDescriptorFromVariable */
/**
* Get ecma-value from variable
*
* @return value descriptor
*/
static void
ctx_SetValueDescriptorToVariable(ctx_SyntacticReference_t *pVar, /**< variable */
ecma_Value_t value) /**< value descriptor */
{
/*
* TODO:
*/
(void)pVar;
(void)value;
JERRY_UNIMPLEMENTED();
} /* ctx_SetValueDescriptorToVariable */
/**
* Allocate a context.
*/
static void
ctx_AllocContext( void)
{
JERRY_ASSERT( ctx_ContextsNumber < CTX_MAX_NUMBER_OF_VARIABLES_CONTEXTS );
ctx_ContextsNumber++;
} /* ctx_AllocContext */
/**
* Create new lexical environment using specified object as binding object,
* setting provideThis to specified value.
* The lexical environment is inherited from current context's lexical environment.
*/
static void
ctx_CreateLexicalEnvironmentFromObject(ecma_Object_t *pObject, /**< pointer to bindingObject */
bool provideThis) /**< value of 'provideThis' attribute */
{
ecma_Object_t *pNewLexicalEnvironment = ecma_CreateLexicalEnvironment(ctx_CurrentContext.pLexicalEnvironment,
true);
/* We don't change reference counter of ctx_CurrentContext.pLexicalEnvironment here,
because we remove one reference from ctx_CurrentContext,
and add one reference from pNewLexicalEnvironment */
ctx_CurrentContext.pLexicalEnvironment = pNewLexicalEnvironment;
ecma_Property_t *pProvideThisProperty = ecma_CreateInternalProperty( pNewLexicalEnvironment, ECMA_INTERNAL_PROPERTY_PROVIDE_THIS);
pProvideThisProperty->u.m_InternalProperty.m_Value = provideThis;
ecma_Property_t *pBindingObjectProperty = ecma_CreateInternalProperty( pNewLexicalEnvironment, ECMA_INTERNAL_PROPERTY_BINDING_OBJECT);
ecma_RefObject( pObject);
ecma_SetPointer( pBindingObjectProperty->u.m_InternalProperty.m_Value, pObject);
} /* ctx_CreateLexicalEnvironmentFromObject */
/**
* Initialize the global object.
*/
static void
ctx_InitGlobalObject( void)
{
ctx_pGlobalObject = ecma_CreateObject( NULL, true);
} /* ctx_InitGlobalObject */
/**
* \addtogroup interface Context manager's interface
* @{
*/
/**
* Initialize context manager and global execution context.
*/
void
ctx_Init(void)
{
JERRY_ASSERT( ctx_ContextsNumber == 0 );
#ifndef JERRY_NDEBUG
libc_memset( ctx_Stack, 0, sizeof (ctx_Stack));
#endif /* !JERRY_NDEBUG */
ctx_InitGlobalObject();
ctx_NewContextFromGlobalObject();
} /* ctx_Init */
/**
* Create new variables' context using global object
* for ThisBinding and lexical environment.
*/
void
ctx_NewContextFromGlobalObject(void)
{
ctx_AllocContext();
ecma_RefObject( ctx_pGlobalObject);
ctx_CurrentContext.pThisBinding = ctx_pGlobalObject;
ctx_CurrentContext.pLexicalEnvironment = NULL;
ctx_CreateLexicalEnvironmentFromObject( ctx_pGlobalObject, false);
JERRY_ASSERT( ctx_CurrentContext.pLexicalEnvironment != NULL );
} /* ctx_NewContextFromGlobalObject */
/**
* Create new variables' context inheriting lexical environment from specified
* function's [[Scope]], and setting ThisBinding from pThisVar parameter
* (see also ECMA-262 5.1, 10.4.3).
*/
void
ctx_NewContextFromFunctionScope(ctx_SyntacticReference_t *pThisVar, /**< object for ThisBinding */
ctx_SyntacticReference_t *pFunctionVar) /**< Function object */
{
ctx_AllocContext();
ecma_Value_t thisArgValue = ctx_GetValueDescriptorFromVariable( pThisVar);
ecma_Value_t functionArgValue = ctx_GetValueDescriptorFromVariable( pFunctionVar);
ecma_Object_t *pThisBindingObject;
if ( thisArgValue.m_ValueType == ECMA_TYPE_SIMPLE
&& ( thisArgValue.m_Value == ECMA_SIMPLE_VALUE_NULL
|| thisArgValue.m_Value == ECMA_SIMPLE_VALUE_UNDEFINED ) )
{
pThisBindingObject = ctx_pGlobalObject;
} else
{
pThisBindingObject = ecma_ToObject( thisArgValue);
}
ecma_RefObject( pThisBindingObject);
ctx_CurrentContext.pThisBinding = pThisBindingObject;
JERRY_ASSERT( functionArgValue.m_ValueType == ECMA_TYPE_OBJECT );
ecma_Object_t *pFunctionObject = ecma_GetPointer( functionArgValue.m_Value);
ecma_Property_t *pScopeProperty = ecma_GetInternalProperty( pFunctionObject, ECMA_INTERNAL_PROPERTY_SCOPE);
ecma_Object_t *pScopeObject = ecma_GetPointer( pScopeProperty->u.m_InternalProperty.m_Value);
ecma_RefObject( pScopeObject);
ecma_Object_t *pLexicalEnvironment = ecma_CreateLexicalEnvironment(pScopeObject, false);
/* We don't change reference counter of ctx_CurrentContext.pLexicalEnvironment here,
because we remove one reference from ctx_CurrentContext,
and add one reference from pNewLexicalEnvironment */
ctx_CurrentContext.pLexicalEnvironment = pLexicalEnvironment;
} /* ctx_NewContextFromFunctionScope */
/**
* Create new lexical environment using specified object as binding object,
* setting provideThis to specified value.
* The lexical environment is inherited from current context's lexical environment.
*/
void
ctx_NewLexicalEnvironmentFromObject(ctx_SyntacticReference_t *pObjectVar, /**< binding object */
bool provideThis) /**< 'provideThis' attribute */
{
ecma_Object_t *pObject = ecma_ToObject( ctx_GetValueDescriptorFromVariable( pObjectVar));
ctx_CreateLexicalEnvironmentFromObject( pObject, provideThis);
} /* ctx_NewLexicalEnvironmentFromObject */
/**
* Exit from levelsToExit lexical environments (i.e. choose lexical environment
* that is levelsToExit outward current lexical environment as new current context's
* lexical environment).
*/
void
ctx_ExitLexicalEnvironments(uint32_t levelsToExit) /**< number of lexical environments
* to exit from */
{
JERRY_ASSERT( levelsToExit > 0 );
for ( uint32_t count = 0;
count < levelsToExit;
count++ )
{
JERRY_ASSERT( ctx_CurrentContext.pLexicalEnvironment != NULL );
ecma_Object_t *pOuterLexicalEnvironment = ecma_GetPointer( ctx_CurrentContext.pLexicalEnvironment->u_Attributes.m_LexicalEnvironment.m_pOuterReference);
ecma_DerefObject( ctx_CurrentContext.pLexicalEnvironment);
ctx_CurrentContext.pLexicalEnvironment = pOuterLexicalEnvironment;
}
JERRY_ASSERT( ctx_CurrentContext.pLexicalEnvironment != NULL );
} /* ctx_ExitLexicalEnvironments */
/**
* Exit from levelsToExit variables' contexts (i.e. choose context
* that is levelsToExit from current context as new current context).
*/
void
ctx_ExitContexts(uint32_t levelsToExit) /**< number of contexts to exit from */
{
JERRY_ASSERT( levelsToExit > 0 );
for ( uint32_t count = 0;
count < levelsToExit;
count++ )
{
JERRY_ASSERT( ctx_ContextsNumber > 0 );
ecma_DerefObject( ctx_CurrentContext.pThisBinding);
while ( ctx_CurrentContext.pLexicalEnvironment != NULL )
{
ecma_Object_t *pOuterLexicalEnvironment =
ecma_GetPointer(ctx_CurrentContext.pLexicalEnvironment->
u_Attributes.m_LexicalEnvironment.
m_pOuterReference);
ecma_DerefObject( ctx_CurrentContext.pLexicalEnvironment);
ctx_CurrentContext.pLexicalEnvironment = pOuterLexicalEnvironment;
}
ctx_ContextsNumber--;
}
JERRY_ASSERT( ctx_ContextsNumber > 0 );
} /* ctx_ExitContexts */
/**
* Create new variable with undefined value in the current lexical environment.
*/
void
ctx_NewVariable( ctx_SyntacticReference_t *pVar) /**< variable id */
{
ecma_Object_t *lexicalEnvironment = ctx_CurrentContext.pLexicalEnvironment;
/*
* TODO:
*/
(void) pVar;
JERRY_UNIMPLEMENTED();
switch ( (ecma_LexicalEnvironmentType_t) lexicalEnvironment->u_Attributes.m_LexicalEnvironment.m_Type )
{
case ECMA_LEXICAL_ENVIRONMENT_OBJECTBOUND:
{
ecma_Property_t *pBindingObjectProperty = ecma_FindInternalProperty(lexicalEnvironment,
ECMA_INTERNAL_PROPERTY_BINDING_OBJECT);
JERRY_ASSERT( pBindingObjectProperty != NULL );
ecma_Object_t *pBindingObject = ecma_GetPointer( pBindingObjectProperty->u.m_InternalProperty.m_Value);
JERRY_ASSERT( pBindingObject != NULL );
break;
}
case ECMA_LEXICAL_ENVIRONMENT_DECLARATIVE:
{
break;
}
}
} /* ctx_NewVariable */
/**
* Delete specified variable.
*/
void
ctx_DeleteVariable( ctx_SyntacticReference_t *pVar) /**< variable id */
{
/*
* TODO:
*/
(void) pVar;
JERRY_UNIMPLEMENTED();
} /* ctx_DeleteVariable */
/**
* Copy variable's/property's/array's element's value.
*/
void
ctx_CopyVariable(ctx_SyntacticReference_t *pVarFrom, /**< source variable */
ctx_SyntacticReference_t *pVarTo) /**< destination variable */
{
ecma_Value_t sourceVariableValue = ctx_GetValueDescriptorFromVariable( pVarFrom);
ecma_Value_t destinationVariableValue;
destinationVariableValue.m_ValueType = sourceVariableValue.m_ValueType;
switch ( (ecma_Type_t) sourceVariableValue.m_ValueType )
{
case ECMA_TYPE_SIMPLE:
{
destinationVariableValue.m_Value = sourceVariableValue.m_Value;
break;
}
case ECMA_TYPE_NUMBER:
{
ecma_Number_t *pNumberCopy = ecma_AllocNumber();
libc_memcpy( pNumberCopy,
ecma_GetPointer( sourceVariableValue.m_Value),
sizeof (ecma_Number_t));
ecma_SetPointer( destinationVariableValue.m_Value, pNumberCopy);
break;
}
case ECMA_TYPE_STRING:
{
ecma_SetPointer(destinationVariableValue.m_Value,
ecma_DuplicateEcmaString( ecma_GetPointer( sourceVariableValue.m_Value)));
break;
}
case ECMA_TYPE_OBJECT:
{
ecma_RefObject( ecma_GetPointer( sourceVariableValue.m_Value));
destinationVariableValue.m_Value = sourceVariableValue.m_Value;
break;
}
case ECMA_TYPE__COUNT:
{
JERRY_UNREACHABLE();
}
}
ctx_SetValueDescriptorToVariable( pVarTo, destinationVariableValue);
} /* ctx_CopyVariable */
/**
* Get type of value of specified variable/property/array's element.
*/
ecma_Type_t
ctx_GetVariableType(ctx_SyntacticReference_t *pVar) /**< variable */
{
ecma_Value_t variableValue = ctx_GetValueDescriptorFromVariable( pVar);
return variableValue.m_ValueType;
} /* ctx_GetVariableType */
/**
* Get specified variable's/property's/array's element's value.
*
* @return number of bytes, actually copied to the buffer, if variable value was copied successfully;
* negative number, which is calculated as negation of buffer size, that is required
* to hold the variable's value (in case size of buffer is insuficcient).
*/
ssize_t
ctx_GetVariableValue(ctx_SyntacticReference_t *pVar, /**< variable */
uint8_t *pBuffer, /**< buffer */
size_t bufferSize) /**< size of buffer */
{
ecma_Value_t variableValue = ctx_GetValueDescriptorFromVariable( pVar);
switch ( (ecma_Type_t) variableValue.m_ValueType )
{
case ECMA_TYPE_SIMPLE:
{
if ( bufferSize < sizeof (ecma_SimpleValue_t) )
{
return -(ssize_t)sizeof (ecma_SimpleValue_t);
} else
{
*(ecma_SimpleValue_t*) pBuffer = variableValue.m_Value;
return sizeof (ecma_SimpleValue_t);
}
break;
}
case ECMA_TYPE_NUMBER:
{
if ( bufferSize < sizeof (ecma_Number_t) )
{
return -(ssize_t)sizeof (ecma_Number_t);
} else
{
ecma_Number_t *pNumber = ecma_GetPointer(variableValue.m_Value);
*(ecma_Number_t*) pBuffer = *pNumber;
return sizeof (ecma_Number_t);
}
break;
}
case ECMA_TYPE_STRING:
{
ecma_ArrayFirstChunk_t *pStringFirstChunk = ecma_GetPointer(variableValue.m_Value);
return ecma_CopyEcmaStringCharsToBuffer( pStringFirstChunk, pBuffer, bufferSize);
}
case ECMA_TYPE_OBJECT: /* cannot return object itself (only value of a property or of an array's element */
case ECMA_TYPE__COUNT:
{
/* will trap below */
}
}
JERRY_UNREACHABLE();
} /* ctx_GetVariableValue */
/**
* Set variable's/property's/array's element's value to one of simple values.
*/
void
ctx_SetVariableToSimpleValue(ctx_SyntacticReference_t *pVar, /**< variable */
ecma_SimpleValue_t value) /**< value */
{
ecma_Value_t valueToSet;
valueToSet.m_ValueType = ECMA_TYPE_SIMPLE;
valueToSet.m_Value = value;
ctx_SetValueDescriptorToVariable( pVar, valueToSet);
} /* ctx_SetVariableToSimpleValue */
/**
* Set variable's/property's/array's element's value to a Number.
*/
void
ctx_SetVariableToNumber(ctx_SyntacticReference_t *pVar, /**< variable */
ecma_Number_t value) /**< value */
{
ecma_Number_t *pNumber = ecma_AllocNumber();
*pNumber = value;
ecma_Value_t valueToSet;
valueToSet.m_ValueType = ECMA_TYPE_NUMBER;
ecma_SetPointer( valueToSet.m_Value, pNumber);
ctx_SetValueDescriptorToVariable( pVar, valueToSet);
} /* ctx_SetVariableToNumber */
/**
* Set variable's/property's/array's element's value to a String.
*/
void
ctx_SetVariableToString(ctx_SyntacticReference_t *pVar, /**< variable */
ecma_Char_t *value, /**< string's characters */
ecma_Length_t length) /**< string's length, in characters */
{
ecma_Value_t valueToSet;
valueToSet.m_ValueType = ECMA_TYPE_STRING;
ecma_SetPointer( valueToSet.m_Value, ecma_NewEcmaString( value, length));
ctx_SetValueDescriptorToVariable( pVar, valueToSet);
} /* ctx_SetVariableToString */
/**
* @}
*/
/**
* Static checks that ecma types fit size requirements.
*
* Warning:
* must not be called
*/
static void __unused
ctx_EcmaTypesSizeCheckers( void)
{
JERRY_STATIC_ASSERT( sizeof (ecma_Value_t) <= sizeof (uint16_t) );
JERRY_STATIC_ASSERT( sizeof (ecma_Property_t) <= sizeof (uint64_t) );
JERRY_STATIC_ASSERT( sizeof (ecma_Object_t) <= sizeof (uint64_t) );
JERRY_STATIC_ASSERT( sizeof (ecma_ArrayHeader_t) <= sizeof (uint32_t) );
JERRY_STATIC_ASSERT( sizeof (ecma_ArrayFirstChunk_t) == ECMA_ARRAY_CHUNK_SIZE_IN_BYTES );
JERRY_STATIC_ASSERT( sizeof (ecma_ArrayNonFirstChunk_t) == ECMA_ARRAY_CHUNK_SIZE_IN_BYTES );
JERRY_UNREACHABLE();
} /* ctx_EcmaTypesSizeCheckers */
/**
* @}
*/