Zoltan Herczeg 110f75c99d Implement the core of the generator functions. (#3368)
Some things are missing:
 - yield* support
 - generator definition in object literal
 - the hidden GeneratorFunction

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com
2019-11-28 11:54:27 +01:00

392 lines
12 KiB
C

/* Copyright JS Foundation and other contributors, http://js.foundation
*
* 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 "ecma-alloc.h"
#include "ecma-gc.h"
#include "ecma-helpers.h"
#include "vm-defines.h"
#include "vm-stack.h"
/** \addtogroup vm Virtual machine
* @{
*
* \addtogroup stack VM stack
* @{
*/
JERRY_STATIC_ASSERT (PARSER_WITH_CONTEXT_STACK_ALLOCATION == PARSER_BLOCK_CONTEXT_STACK_ALLOCATION,
parser_with_context_stack_allocation_must_be_equal_to_parser_block_context_stack_allocation);
JERRY_STATIC_ASSERT (PARSER_WITH_CONTEXT_STACK_ALLOCATION == PARSER_SUPER_CLASS_CONTEXT_STACK_ALLOCATION,
parser_with_context_stack_allocation_must_be_equal_to_parser_super_class_context_stack_allocation);
/**
* Abort (finalize) the current stack context, and remove it.
*
* @return new stack top
*/
ecma_value_t *
vm_stack_context_abort (vm_frame_ctx_t *frame_ctx_p, /**< frame context */
ecma_value_t *vm_stack_top_p) /**< current stack top */
{
ecma_value_t context_info = vm_stack_top_p[-1];
if (context_info & VM_CONTEXT_HAS_LEX_ENV)
{
ecma_object_t *lex_env_p = frame_ctx_p->lex_env_p;
JERRY_ASSERT (lex_env_p->u2.outer_reference_cp != JMEM_CP_NULL);
frame_ctx_p->lex_env_p = ECMA_GET_NON_NULL_POINTER (ecma_object_t, lex_env_p->u2.outer_reference_cp);
ecma_deref_object (lex_env_p);
}
switch (VM_GET_CONTEXT_TYPE (context_info))
{
case VM_CONTEXT_FINALLY_THROW:
case VM_CONTEXT_FINALLY_RETURN:
{
ecma_free_value (vm_stack_top_p[-2]);
/* FALLTHRU */
}
case VM_CONTEXT_FINALLY_JUMP:
case VM_CONTEXT_TRY:
case VM_CONTEXT_CATCH:
{
VM_MINUS_EQUAL_U16 (frame_ctx_p->context_depth, PARSER_TRY_CONTEXT_STACK_ALLOCATION);
vm_stack_top_p -= PARSER_TRY_CONTEXT_STACK_ALLOCATION;
break;
}
#if ENABLED (JERRY_ES2015)
case VM_CONTEXT_BLOCK:
case VM_CONTEXT_SUPER_CLASS:
#endif /* ENABLED (JERRY_ES2015) */
case VM_CONTEXT_WITH:
{
VM_MINUS_EQUAL_U16 (frame_ctx_p->context_depth, PARSER_WITH_CONTEXT_STACK_ALLOCATION);
vm_stack_top_p -= PARSER_WITH_CONTEXT_STACK_ALLOCATION;
break;
}
#if ENABLED (JERRY_ES2015)
case VM_CONTEXT_FOR_OF:
{
ecma_free_value (vm_stack_top_p[-2]);
ecma_free_value (vm_stack_top_p[-3]);
VM_MINUS_EQUAL_U16 (frame_ctx_p->context_depth, PARSER_FOR_OF_CONTEXT_STACK_ALLOCATION);
vm_stack_top_p -= PARSER_FOR_OF_CONTEXT_STACK_ALLOCATION;
break;
}
#endif /* ENABLED (JERRY_ES2015) */
default:
{
JERRY_ASSERT (VM_GET_CONTEXT_TYPE (vm_stack_top_p[-1]) == VM_CONTEXT_FOR_IN);
ecma_collection_t *collection_p;
collection_p = ECMA_GET_INTERNAL_VALUE_POINTER (ecma_collection_t, vm_stack_top_p[-2]);
ecma_value_t *buffer_p = collection_p->buffer_p;
for (uint32_t index = vm_stack_top_p[-3]; index < collection_p->item_count; index++)
{
ecma_free_value (buffer_p[index]);
}
ecma_collection_destroy (collection_p);
ecma_free_value (vm_stack_top_p[-4]);
VM_MINUS_EQUAL_U16 (frame_ctx_p->context_depth, PARSER_FOR_IN_CONTEXT_STACK_ALLOCATION);
vm_stack_top_p -= PARSER_FOR_IN_CONTEXT_STACK_ALLOCATION;
break;
}
}
return vm_stack_top_p;
} /* vm_stack_context_abort */
/**
* Decode branch offset.
*
* @return branch offset
*/
static uint32_t
vm_decode_branch_offset (uint8_t *branch_offset_p, /**< start offset of byte code */
uint32_t length) /**< length of the branch */
{
uint32_t branch_offset = *branch_offset_p;
JERRY_ASSERT (length >= 1 && length <= 3);
switch (length)
{
case 3:
{
branch_offset <<= 8;
branch_offset |= *(++branch_offset_p);
/* FALLTHRU */
}
case 2:
{
branch_offset <<= 8;
branch_offset |= *(++branch_offset_p);
break;
}
}
return branch_offset;
} /* vm_decode_branch_offset */
/**
* Find a finally up to the end position.
*
* @return true - if 'finally' found,
* false - otherwise
*/
bool
vm_stack_find_finally (vm_frame_ctx_t *frame_ctx_p, /**< frame context */
ecma_value_t **vm_stack_top_ref_p, /**< current stack top */
vm_stack_context_type_t finally_type, /**< searching this finally */
uint32_t search_limit) /**< search up-to this byte code */
{
ecma_value_t *vm_stack_top_p = *vm_stack_top_ref_p;
JERRY_ASSERT (finally_type <= VM_CONTEXT_FINALLY_RETURN);
if (finally_type != VM_CONTEXT_FINALLY_JUMP)
{
search_limit = 0xffffffffu;
}
while (frame_ctx_p->context_depth > 0)
{
vm_stack_context_type_t context_type;
uint32_t context_end = VM_GET_CONTEXT_END (vm_stack_top_p[-1]);
if (search_limit < context_end)
{
*vm_stack_top_ref_p = vm_stack_top_p;
return false;
}
context_type = VM_GET_CONTEXT_TYPE (vm_stack_top_p[-1]);
if (context_type == VM_CONTEXT_TRY || context_type == VM_CONTEXT_CATCH)
{
uint8_t *byte_code_p;
uint32_t branch_offset_length;
uint32_t branch_offset;
if (search_limit == context_end)
{
*vm_stack_top_ref_p = vm_stack_top_p;
return false;
}
#if ENABLED (JERRY_ES2015)
if (vm_stack_top_p[-1] & VM_CONTEXT_HAS_LEX_ENV)
{
ecma_object_t *lex_env_p = frame_ctx_p->lex_env_p;
JERRY_ASSERT (lex_env_p->u2.outer_reference_cp != JMEM_CP_NULL);
frame_ctx_p->lex_env_p = ECMA_GET_NON_NULL_POINTER (ecma_object_t, lex_env_p->u2.outer_reference_cp);
ecma_deref_object (lex_env_p);
}
#endif /* ENABLED (JERRY_ES2015) */
byte_code_p = frame_ctx_p->byte_code_start_p + context_end;
if (context_type == VM_CONTEXT_TRY)
{
JERRY_ASSERT (byte_code_p[0] == CBC_EXT_OPCODE);
if (byte_code_p[1] >= CBC_EXT_CATCH
&& byte_code_p[1] <= CBC_EXT_CATCH_3)
{
branch_offset_length = CBC_BRANCH_OFFSET_LENGTH (byte_code_p[1]);
branch_offset = vm_decode_branch_offset (byte_code_p + 2,
branch_offset_length);
if (finally_type == VM_CONTEXT_FINALLY_THROW)
{
branch_offset += (uint32_t) (byte_code_p - frame_ctx_p->byte_code_start_p);
vm_stack_top_p[-1] = VM_CREATE_CONTEXT (VM_CONTEXT_CATCH, branch_offset);
byte_code_p += 2 + branch_offset_length;
frame_ctx_p->byte_code_p = byte_code_p;
*vm_stack_top_ref_p = vm_stack_top_p;
return true;
}
byte_code_p += branch_offset;
if (*byte_code_p == CBC_CONTEXT_END)
{
VM_MINUS_EQUAL_U16 (frame_ctx_p->context_depth, PARSER_TRY_CONTEXT_STACK_ALLOCATION);
vm_stack_top_p -= PARSER_TRY_CONTEXT_STACK_ALLOCATION;
continue;
}
}
}
else
{
#if !ENABLED (JERRY_ES2015)
if (vm_stack_top_p[-1] & VM_CONTEXT_HAS_LEX_ENV)
{
ecma_object_t *lex_env_p = frame_ctx_p->lex_env_p;
JERRY_ASSERT (lex_env_p->u2.outer_reference_cp != JMEM_CP_NULL);
frame_ctx_p->lex_env_p = ECMA_GET_NON_NULL_POINTER (ecma_object_t, lex_env_p->u2.outer_reference_cp);
ecma_deref_object (lex_env_p);
}
#endif /* !ENABLED (JERRY_ES2015) */
if (byte_code_p[0] == CBC_CONTEXT_END)
{
VM_MINUS_EQUAL_U16 (frame_ctx_p->context_depth, PARSER_TRY_CONTEXT_STACK_ALLOCATION);
vm_stack_top_p -= PARSER_TRY_CONTEXT_STACK_ALLOCATION;
continue;
}
}
JERRY_ASSERT (byte_code_p[0] == CBC_EXT_OPCODE);
JERRY_ASSERT (byte_code_p[1] >= CBC_EXT_FINALLY
&& byte_code_p[1] <= CBC_EXT_FINALLY_3);
branch_offset_length = CBC_BRANCH_OFFSET_LENGTH (byte_code_p[1]);
branch_offset = vm_decode_branch_offset (byte_code_p + 2,
branch_offset_length);
branch_offset += (uint32_t) (byte_code_p - frame_ctx_p->byte_code_start_p);
vm_stack_top_p[-1] = VM_CREATE_CONTEXT ((uint32_t) finally_type, branch_offset);
byte_code_p += 2 + branch_offset_length;
frame_ctx_p->byte_code_p = byte_code_p;
*vm_stack_top_ref_p = vm_stack_top_p;
return true;
}
vm_stack_top_p = vm_stack_context_abort (frame_ctx_p, vm_stack_top_p);
}
*vm_stack_top_ref_p = vm_stack_top_p;
return false;
} /* vm_stack_find_finally */
#if ENABLED (JERRY_ES2015)
/**
* Get the offsets of ecma values from the specified item of a context.
*
* @return array of offsets, last item represents the size of the context item
*/
uint32_t
vm_get_context_value_offsets (ecma_value_t *context_item_p) /**< any item of a context */
{
switch (VM_GET_CONTEXT_TYPE (context_item_p[-1]))
{
case VM_CONTEXT_FINALLY_THROW:
case VM_CONTEXT_FINALLY_RETURN:
{
return (2 << (VM_CONTEXT_OFFSET_SHIFT)) | PARSER_TRY_CONTEXT_STACK_ALLOCATION;
}
case VM_CONTEXT_FINALLY_JUMP:
case VM_CONTEXT_TRY:
case VM_CONTEXT_CATCH:
{
return PARSER_TRY_CONTEXT_STACK_ALLOCATION;
}
#if ENABLED (JERRY_ES2015)
case VM_CONTEXT_BLOCK:
case VM_CONTEXT_SUPER_CLASS:
#endif /* ENABLED (JERRY_ES2015) */
case VM_CONTEXT_WITH:
{
return PARSER_WITH_CONTEXT_STACK_ALLOCATION;
}
#if ENABLED (JERRY_ES2015)
case VM_CONTEXT_FOR_OF:
{
return ((3 << (VM_CONTEXT_OFFSET_SHIFT * 2))
| (2 << (VM_CONTEXT_OFFSET_SHIFT))
| PARSER_FOR_OF_CONTEXT_STACK_ALLOCATION);
}
#endif /* ENABLED (JERRY_ES2015) */
default:
{
return (4 << (VM_CONTEXT_OFFSET_SHIFT)) | PARSER_FOR_IN_CONTEXT_STACK_ALLOCATION;
}
}
} /* vm_get_context_value_offsets */
/**
* Ref / deref lexical environments in the chain using the current context.
*/
void
vm_ref_lex_env_chain (ecma_object_t *lex_env_p, /**< top of lexical environment */
uint16_t context_depth, /**< depth of function context */
ecma_value_t *context_end_p, /**< end of function context */
bool do_ref) /**< ref or deref lexical environments */
{
ecma_value_t *context_top_p = context_end_p + context_depth;
JERRY_ASSERT (context_top_p > context_end_p);
do
{
if (context_top_p[-1] & VM_CONTEXT_HAS_LEX_ENV)
{
JERRY_ASSERT (lex_env_p->u2.outer_reference_cp != JMEM_CP_NULL);
ecma_object_t *next_lex_env_p = ECMA_GET_NON_NULL_POINTER (ecma_object_t, lex_env_p->u2.outer_reference_cp);
if (do_ref)
{
ecma_ref_object (lex_env_p);
}
else
{
ecma_deref_object (lex_env_p);
}
lex_env_p = next_lex_env_p;
}
uint32_t offsets = vm_get_context_value_offsets (context_top_p);
while (VM_CONTEXT_HAS_NEXT_OFFSET (offsets))
{
int32_t offset = VM_CONTEXT_GET_NEXT_OFFSET (offsets);
if (do_ref)
{
ecma_ref_if_object (context_top_p[offset]);
}
else
{
ecma_deref_if_object (context_top_p[offset]);
}
offsets >>= VM_CONTEXT_OFFSET_SHIFT;
}
JERRY_ASSERT (context_top_p >= context_end_p + offsets);
context_top_p -= offsets;
}
while (context_top_p > context_end_p);
} /* vm_ref_lex_env_chain */
#endif /* ENABLED (JERRY_ES2015) */
/**
* @}
* @}
*/