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Merged
ruben-ayrapetyan merged 7 commits into from
May 29, 2015
Merged

Instantiation of Arguments object #102

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3a9bf24
Update of several 'vm' component interfaces naming.
May 25, 2015
e984bc3
Fix of 'strict mode' meta type handling in opfunc_meta.
May 25, 2015
cb600da
Introducing 'scope flags' opcode containing set of flags that indicat…
May 26, 2015
b1a31c8
Adding scope's code flags indicating whether the scope's code referen…
May 26, 2015
ed4ff8e
Introducing a function object's flag indicating whether Arguments obj…
May 26, 2015
d4537eb
Instantiation of Arguments object.
May 26, 2015
77df022
Adding jerry-test-suite tests on Arguments object to precommit testin…
May 27, 2015
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Introducing a function object's flag indicating whether Arguments obj… 
…ect should be instantiated upon call of the function.

 The Arguments object is supposed to be unnecessary if function's code:
  - doesn't reference 'arguments' identifier;
  - doesn't reference 'eval' identifier (so, it doesn't perform direct call to eval).

JerryScript-DCO-1.0-Signed-off-by: Ruben Ayrapetyan [email protected]
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Ruben Ayrapetyan committed May 28, 2015
commit ed4ff8e5bb3c66353e2f98370d7842b1265128fd
73 changes: 59 additions & 14 deletions jerry-core/ecma/operations/ecma-function-object.cpp
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Expand Up @@ -37,48 +37,60 @@
*/

/**
* Pack 'is_strict' flag and opcode index to value
* Pack 'is_strict', 'do_instantiate_arguments_object' flags and opcode index to value
* that can be stored in an [[Code]] internal property.
*
* @return packed value
*/
static uint32_t
ecma_pack_code_internal_property_value (bool is_strict, /**< is code strict? */
bool do_instantiate_args_obj, /**< should an Arguments object be
* instantiated for the code */
opcode_counter_t opcode_idx) /**< index of first opcode */
{
uint32_t value = opcode_idx;
const uint32_t is_strict_bit_offset = (uint32_t) (sizeof (value) * JERRY_BITSINBYTE - 1);
const uint32_t do_instantiate_arguments_object_bit_offset = (uint32_t) (sizeof (value) * JERRY_BITSINBYTE - 2);

JERRY_ASSERT (((value) & (1u << is_strict_bit_offset)) == 0);
JERRY_ASSERT (((value) & (1u << do_instantiate_arguments_object_bit_offset)) == 0);

if (is_strict)
{
value |= (1u << is_strict_bit_offset);
}

if (do_instantiate_args_obj)
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@egavrin egavrin May 27, 2015

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Please, add blank line before if.

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@ruben-ayrapetyan ruben-ayrapetyan May 27, 2015

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Ok.

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@ruben-ayrapetyan ruben-ayrapetyan May 27, 2015

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Done.

{
value |= (1u << do_instantiate_arguments_object_bit_offset);
}

return value;
} /* ecma_pack_code_internal_property_value */

/**
* Unpack 'is_strict' flag and opcode index from value
* Unpack 'is_strict', 'do_instantiate_arguments_object' flags and opcode index from value
* that can be stored in an [[Code]] internal property.
*
* @return opcode index
*/
static opcode_counter_t
ecma_unpack_code_internal_property_value (uint32_t value, /**< packed value */
bool* out_is_strict_p) /**< out: is code strict? */
bool* out_is_strict_p, /**< out: is code strict? */
bool* out_do_instantiate_args_obj_p) /**< should an Arguments object be
* instantiated for the code */
{
JERRY_ASSERT (out_is_strict_p != NULL);
JERRY_ASSERT (out_do_instantiate_args_obj_p != NULL);

const uint32_t is_strict_bit_offset = (uint32_t) (sizeof (value) * JERRY_BITSINBYTE - 1);
const uint32_t do_instantiate_arguments_object_bit_offset = (uint32_t) (sizeof (value) * JERRY_BITSINBYTE - 2);

bool is_strict = ((value & (1u << is_strict_bit_offset)) != 0);
*out_is_strict_p = is_strict;

opcode_counter_t opcode_idx = (opcode_counter_t) (value & ~(1u << is_strict_bit_offset));
*out_is_strict_p = ((value & (1u << is_strict_bit_offset)) != 0);
*out_do_instantiate_args_obj_p = ((value & (1u << do_instantiate_arguments_object_bit_offset)) != 0);
value &= ~((1u << is_strict_bit_offset) | (1u << do_instantiate_arguments_object_bit_offset));

return opcode_idx;
return (opcode_counter_t) value;
} /* ecma_unpack_code_internal_property_value */

/**
Expand Down Expand Up @@ -144,6 +156,8 @@ ecma_op_create_function_object (ecma_string_t* formal_parameter_list_p[], /**< f
ecma_length_t formal_parameters_number, /**< formal parameters list's length */
ecma_object_t *scope_p, /**< function's scope */
bool is_strict, /**< 'strict' flag */
bool do_instantiate_arguments_object, /**< should an Arguments object be instantiated
* for the function object upon call */
opcode_counter_t first_opcode_idx) /**< index of first opcode of function's body */
{
// 1., 4., 13.
Expand Down Expand Up @@ -185,6 +199,7 @@ ecma_op_create_function_object (ecma_string_t* formal_parameter_list_p[], /**< f
// 12.
ecma_property_t *code_prop_p = ecma_create_internal_property (f, ECMA_INTERNAL_PROPERTY_CODE);
code_prop_p->u.internal_property.value = ecma_pack_code_internal_property_value (is_strict,
do_instantiate_arguments_object,
first_opcode_idx);

// 14.
Expand Down Expand Up @@ -339,10 +354,11 @@ ecma_op_create_external_function_object (ecma_external_pointer_t code_p) /**< po
} /* ecma_op_create_external_function_object */

/**
* Setup variables for arguments listed in formal parameter list.
* Setup variables for arguments listed in formal parameter list,
* and, if necessary, Arguments object with 'arguments' binding.
*
* See also:
* Declaration binding instantiation (ECMA-262 v5, 10.5), block 4
* Declaration binding instantiation (ECMA-262 v5, 10.5), block 4 and 7
*
* @return completion value
* Returned value must be freed with ecma_free_completion_value
Expand All @@ -352,7 +368,10 @@ ecma_function_call_setup_args_variables (ecma_object_t *func_obj_p, /**< Functio
ecma_object_t *env_p, /**< lexical environment */
const ecma_value_t *arguments_list_p, /**< arguments list */
ecma_length_t arguments_list_len, /**< length of argument list */
bool is_strict) /**< flag indicating strict mode */
bool is_strict, /**< flag indicating strict mode */
bool do_instantiate_arguments_object) /**< flag indicating whether
* Arguments object should be
* instantiated */
{
ecma_property_t *formal_parameters_prop_p = ecma_get_internal_property (func_obj_p,
ECMA_INTERNAL_PROPERTY_FORMAL_PARAMETERS);
Expand Down Expand Up @@ -417,6 +436,24 @@ ecma_function_call_setup_args_variables (ecma_object_t *func_obj_p, /**< Functio
}
}

if (do_instantiate_arguments_object)
{
/*
* According to ECMA-262 v5, 10.5, the Arguments object should be instantiated
* after instantiating declared functions, and only if there is no binding named 'arguments'
* by that time.
*
* However, we can setup Arguments object and 'arguments' binding here, because:
* - instantiation of Arguments object itself doesn't have any side effects;
* - if 'arguments' is name of a declared function in current scope,
* value of the binding would be overwritten, execution would proceed in correct state.
* - declaration of function, named 'arguments', is considered to be unrecommended (and so, rare) case,
* so instantiation of Arguments object here, in general, is supposed to not affect resource consumption
* significantly.
*/
JERRY_UNIMPLEMENTED ("Instantiate Arguments object and setup 'arguments' implicit variable");
}

return ecma_make_empty_completion_value ();
} /* ecma_function_call_setup_args_variables */

Expand Down Expand Up @@ -543,8 +580,11 @@ ecma_op_function_call (ecma_object_t *func_obj_p, /**< Function object */
uint32_t code_prop_value = code_prop_p->u.internal_property.value;

bool is_strict;
bool do_instantiate_args_obj;
// 8.
opcode_counter_t code_first_opcode_idx = ecma_unpack_code_internal_property_value (code_prop_value, &is_strict);
opcode_counter_t code_first_opcode_idx = ecma_unpack_code_internal_property_value (code_prop_value,
&is_strict,
&do_instantiate_args_obj);

ecma_value_t this_binding;
// 1.
Expand Down Expand Up @@ -576,7 +616,8 @@ ecma_op_function_call (ecma_object_t *func_obj_p, /**< Function object */
local_env_p,
arguments_list_p,
arguments_list_len,
is_strict),
is_strict,
do_instantiate_args_obj),
ret_value);

ecma_completion_value_t completion = vm_run_from_pos (code_first_opcode_idx,
Expand Down Expand Up @@ -769,14 +810,18 @@ ecma_op_function_declaration (ecma_object_t *lex_env_p, /**< lexical environment
ecma_string_t* formal_parameter_list_p[], /**< formal parameters list */
ecma_length_t formal_parameter_list_length, /**< length of formal parameters list */
bool is_strict, /**< flag indicating if function is declared in strict mode code */
bool do_instantiate_arguments_object, /**< flag, indicating whether an Arguments object
* should be instantiated for the function object
* upon call */
bool is_configurable_bindings) /**< flag indicating whether function
is declared in eval code */
* is declared in eval code */
{
// b.
ecma_object_t *func_obj_p = ecma_op_create_function_object (formal_parameter_list_p,
formal_parameter_list_length,
lex_env_p,
is_strict,
do_instantiate_arguments_object,
function_code_opcode_idx);

// c.
Expand Down
2 changes: 2 additions & 0 deletions jerry-core/ecma/operations/ecma-function-object.h
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Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,7 @@ ecma_op_create_function_object (ecma_string_t* formal_parameter_list_p[],
ecma_length_t formal_parameters_number,
ecma_object_t *scope_p,
bool is_strict,
bool do_instantiate_arguments_object,
opcode_counter_t first_opcode_idx);
extern ecma_object_t*
ecma_op_create_external_function_object (ecma_external_pointer_t code_p);
Expand All @@ -60,6 +61,7 @@ ecma_op_function_declaration (ecma_object_t *lex_env_p,
ecma_string_t* formal_parameter_list_p[],
ecma_length_t formal_parameter_list_length,
bool is_strict,
bool do_instantiate_arguments_object,
bool is_configurable_bindings);

/**
Expand Down
20 changes: 20 additions & 0 deletions jerry-core/vm/opcodes.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -443,6 +443,7 @@ function_declaration (int_data_t *int_data, /**< interpreter context */
ecma_length_t args_number) /**< number of arguments */
{
bool is_strict = int_data->is_strict;
bool do_instantiate_arguments_object = true;
const bool is_configurable_bindings = int_data->is_eval_code;

const opcode_counter_t function_code_end_oc = (opcode_counter_t) (
Expand All @@ -455,6 +456,14 @@ function_declaration (int_data_t *int_data, /**< interpreter context */
{
is_strict = true;
}
if ((scope_flags & OPCODE_SCOPE_CODE_FLAGS_NOT_REF_ARGUMENTS_IDENTIFIER)
&& (scope_flags & OPCODE_SCOPE_CODE_FLAGS_NOT_REF_EVAL_IDENTIFIER))
{
/* the code doesn't use 'arguments' identifier
* and doesn't perform direct call to eval,
* so Arguments object can't be referenced */
do_instantiate_arguments_object = false;
}

ecma_string_t *function_name_string_p = ecma_new_ecma_string_from_lit_index (function_name_lit_id);

Expand All @@ -464,6 +473,7 @@ function_declaration (int_data_t *int_data, /**< interpreter context */
args_names,
args_number,
is_strict,
do_instantiate_arguments_object,
is_configurable_bindings);
ecma_deref_ecma_string (function_name_string_p);

Expand Down Expand Up @@ -541,6 +551,7 @@ opfunc_func_expr_n (opcode_t opdata, /**< operation data */
fill_params_list (int_data, params_number, params_names);

bool is_strict = int_data->is_strict;
bool do_instantiate_arguments_object = true;

function_code_end_oc = (opcode_counter_t) (read_meta_opcode_counter (OPCODE_META_TYPE_FUNCTION_END,
int_data) + int_data->pos);
Expand All @@ -552,6 +563,14 @@ opfunc_func_expr_n (opcode_t opdata, /**< operation data */
{
is_strict = true;
}
if ((scope_flags & OPCODE_SCOPE_CODE_FLAGS_NOT_REF_ARGUMENTS_IDENTIFIER)
&& (scope_flags & OPCODE_SCOPE_CODE_FLAGS_NOT_REF_EVAL_IDENTIFIER))
{
/* the code doesn't use 'arguments' identifier
* and doesn't perform direct call to eval,
* so Arguments object can't be referenced */
do_instantiate_arguments_object = false;
}

ecma_object_t *scope_p;
ecma_string_t *function_name_string_p = NULL;
Expand All @@ -576,6 +595,7 @@ opfunc_func_expr_n (opcode_t opdata, /**< operation data */
params_number,
scope_p,
is_strict,
do_instantiate_arguments_object,
int_data->pos);

ret_value = set_variable_value (int_data, lit_oc,
Expand Down