/* Copyright 2014-2016 Samsung Electronics Co., Ltd. * Copyright 2015-2016 University of Szeged. * * 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 * @{ */ /** * 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 */ { switch (VM_GET_CONTEXT_TYPE (vm_stack_top_p[-1])) { case VM_CONTEXT_FINALLY_THROW: case VM_CONTEXT_FINALLY_RETURN: { ecma_free_value (vm_stack_top_p[-2]); VM_MINUS_EQUAL_U16 (frame_ctx_p->context_depth, PARSER_TRY_CONTEXT_STACK_ALLOCATION); vm_stack_top_p -= PARSER_TRY_CONTEXT_STACK_ALLOCATION; break; } case VM_CONTEXT_FINALLY_JUMP: case VM_CONTEXT_TRY: { VM_MINUS_EQUAL_U16 (frame_ctx_p->context_depth, PARSER_TRY_CONTEXT_STACK_ALLOCATION); vm_stack_top_p -= PARSER_TRY_CONTEXT_STACK_ALLOCATION; break; } case VM_CONTEXT_CATCH: case VM_CONTEXT_WITH: { ecma_deref_object (frame_ctx_p->lex_env_p); frame_ctx_p->lex_env_p = ecma_get_object_from_value (vm_stack_top_p[-2]); JERRY_ASSERT (PARSER_TRY_CONTEXT_STACK_ALLOCATION == PARSER_WITH_CONTEXT_STACK_ALLOCATION); VM_MINUS_EQUAL_U16 (frame_ctx_p->context_depth, PARSER_TRY_CONTEXT_STACK_ALLOCATION); vm_stack_top_p -= PARSER_TRY_CONTEXT_STACK_ALLOCATION; break; } case VM_CONTEXT_FOR_IN: { jmem_cpointer_t current = (jmem_cpointer_t) vm_stack_top_p[-2]; while (current != JMEM_CP_NULL) { ecma_collection_chunk_t *chunk_p = JMEM_CP_GET_NON_NULL_POINTER (ecma_collection_chunk_t, current); lit_utf8_byte_t *data_ptr = chunk_p->data; ecma_free_value (*(ecma_value_t *) data_ptr); current = chunk_p->next_chunk_cp; ecma_dealloc_collection_chunk (chunk_p); } ecma_free_value (vm_stack_top_p[-3]); 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; } default: { JERRY_UNREACHABLE (); 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; } byte_code_p = frame_ctx_p->byte_code_start_p + VM_GET_CONTEXT_END (vm_stack_top_p[-1]); 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 { ecma_deref_object (frame_ctx_p->lex_env_p); frame_ctx_p->lex_env_p = ecma_get_object_from_value (vm_stack_top_p[-2]); 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 */ /** * @} * @} */