Import of the watch repository from Pebble

third_party/jerryscript/jerry-core/vm/vm-stack.c

@@ -0,0 +1,256 @@
+/* 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 */
+
+/**
+ * @}
+ * @}
+ */