Support labelled statements.

Related issue: #52

JerryScript-DCO-1.0-Signed-off-by: Ruben Ayrapetyan [email protected]

Author: ruben-ayrapetyan

jerry-core/parser/js/jsp-label.cpp

@@ -0,0 +1,295 @@
+/* Copyright 2015 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 "jsp-label.h"
+#include "lexer.h"
+#include "opcodes-dumper.h"
+
+/** \addtogroup jsparser ECMAScript parser
+ * @{
+ *
+ * \addtogroup labels Jump labels
+ * @{
+ */
+
+/**
+ * Stack, containing current label set
+ */
+jsp_label_t *label_set_p = NULL;
+
+/**
+ * Initialize jumps labels mechanism
+ */
+void
+jsp_label_init (void)
+{
+  JERRY_ASSERT (label_set_p == NULL);
+} /* jsp_label_init */
+
+/**
+ * Finalize jumps labels mechanism
+ */
+void
+jsp_label_finalize (void)
+{
+  JERRY_ASSERT (label_set_p == NULL);
+} /* jsp_label_finalize */
+
+/**
+ * Add label to the current label set
+ */
+void
+jsp_label_push (jsp_label_t *out_label_p, /**< out: place where label structure
+                                           *        should be initialized and
+                                           *        linked into label set stack */
+                jsp_label_type_flag_t type_mask, /**< label's type mask */
+                token id) /**< identifier of the label (TOK_NAME)
+                           *   if mask includes JSP_LABEL_TYPE_NAMED,
+                           *   or empty token - otherwise */
+{
+  JERRY_ASSERT (out_label_p != NULL);
+
+  if (type_mask & JSP_LABEL_TYPE_NAMED)
+  {
+    JERRY_ASSERT (id.type == TOK_NAME);
+
+    JERRY_ASSERT (jsp_label_find (JSP_LABEL_TYPE_NAMED, id, NULL) == NULL);
+  }
+  else
+  {
+    JERRY_ASSERT (id.type == TOK_EMPTY);
+  }
+
+  out_label_p->type_mask = type_mask;
+  out_label_p->id = id;
+  out_label_p->continue_tgt_oc = MAX_OPCODES;
+  out_label_p->breaks_list_oc = MAX_OPCODES;
+  out_label_p->breaks_number = 0;
+  out_label_p->continues_list_oc = MAX_OPCODES;
+  out_label_p->continues_number = 0;
+  out_label_p->next_label_p = label_set_p;
+  out_label_p->is_nested_jumpable_border = false;
+
+  label_set_p = out_label_p;
+} /* jsp_label_push */
+
+/**
+ * Rewrite jumps to the label, if there any,
+ * and remove it from the current label set
+ *
+ * @return the label should be on top of label set stack
+ */
+void
+jsp_label_rewrite_jumps_and_pop (jsp_label_t *label_p, /**< label to remove (should be on top of stack) */
+                                 opcode_counter_t break_tgt_oc) /**< target opcode counter
+                                                                 *  for breaks on the label */
+{
+  JERRY_ASSERT (label_p != NULL);
+  JERRY_ASSERT (break_tgt_oc != MAX_OPCODES);
+  JERRY_ASSERT (label_set_p == label_p);
+
+  /* Iterating jumps list, rewriting them */
+  while (label_p->breaks_number--)
+  {
+    JERRY_ASSERT (label_p->breaks_list_oc != MAX_OPCODES);
+
+    label_p->breaks_list_oc = rewrite_simple_or_nested_jump_and_get_next (label_p->breaks_list_oc,
+                                                                          break_tgt_oc);
+  }
+  while (label_p->continues_number--)
+  {
+    JERRY_ASSERT (label_p->continue_tgt_oc != MAX_OPCODES);
+    JERRY_ASSERT (label_p->continues_list_oc != MAX_OPCODES);
+
+    label_p->continues_list_oc = rewrite_simple_or_nested_jump_and_get_next (label_p->continues_list_oc,
+                                                                             label_p->continue_tgt_oc);
+  }
+
+  label_set_p = label_set_p->next_label_p;
+} /* jsp_label_rewrite_jumps_and_pop */
+
+/**
+ * Find label with specified identifier
+ *
+ * @return if found, pointer to label descriptor,
+ *         otherwise - NULL.
+ */
+jsp_label_t*
+jsp_label_find (jsp_label_type_flag_t type_mask, /**< types to search for */
+                token id, /**< identifier of the label (TOK_NAME)
+                           *   if mask equals to JSP_LABEL_TYPE_NAMED,
+                           *   or empty token - otherwise
+                           *   (if so, mask should not include JSP_LABEL_TYPE_NAMED) */
+                bool *out_is_simply_jumpable_p) /**< out: is the label currently
+                                                 *        accessible with a simple jump */
+{
+  bool is_search_named = (type_mask == JSP_LABEL_TYPE_NAMED);
+
+  if (is_search_named)
+  {
+    JERRY_ASSERT (id.type == TOK_NAME);
+  }
+  else
+  {
+    JERRY_ASSERT (!(type_mask & JSP_LABEL_TYPE_NAMED));
+    JERRY_ASSERT (id.type == TOK_EMPTY);
+  }
+
+  bool is_simply_jumpable = true;
+  jsp_label_t *ret_label_p = NULL;
+
+  for (jsp_label_t* label_iter_p = label_set_p;
+       label_iter_p != NULL;
+       label_iter_p = label_iter_p->next_label_p)
+  {
+    if (label_iter_p->is_nested_jumpable_border)
+    {
+      is_simply_jumpable = false;
+    }
+
+    bool is_named_label = (label_iter_p->type_mask & JSP_LABEL_TYPE_NAMED);
+    if ((is_search_named
+         && is_named_label
+         && lexer_are_tokens_with_same_identifier (label_iter_p->id, id))
+        || (!is_search_named
+            && (type_mask & label_iter_p->type_mask)))
+    {
+      ret_label_p = label_iter_p;
+
+      break;
+    }
+  }
+
+  if (out_is_simply_jumpable_p != NULL)
+  {
+    *out_is_simply_jumpable_p = is_simply_jumpable;
+  }
+
+  return ret_label_p;
+} /* jsp_label_find */
+
+/**
+ * Dump jump and register it in the specified label to be rewritten later (see also: jsp_label_rewrite_jumps_and_pop)
+ *
+ * Warning:
+ *         The dumped instruction should not be modified before it is rewritten, as its idx fields are used
+ *         to link jump instructions related to the label into singly linked list.
+ */
+void
+jsp_label_add_jump (jsp_label_t *label_p, /**< label to register jump for */
+                    bool is_simply_jumpable, /**< is the label currently
+                                              *    accessible with a simple jump */
+                    bool is_break) /**< type of jump - 'break' (true) or 'continue' (false) */
+{
+  JERRY_ASSERT (label_p != NULL);
+
+  if (is_break)
+  {
+    label_p->breaks_list_oc = dump_simple_or_nested_jump_for_rewrite (is_simply_jumpable,
+                                                                      label_p->breaks_list_oc);
+    label_p->breaks_number++;
+  }
+  else
+  {
+    label_p->continues_list_oc = dump_simple_or_nested_jump_for_rewrite (is_simply_jumpable,
+                                                                         label_p->continues_list_oc);
+    label_p->continues_number++;
+  }
+} /* jsp_label_add_jump */
+
+/**
+ * Setup target for 'continue' jumps,
+ * associated with the labels, from innermost
+ * to the specified label.
+ */
+void
+jsp_label_setup_continue_target (jsp_label_t *outermost_label_p, /**< the outermost label to setup target for */
+                                 opcode_counter_t tgt_oc) /**< target */
+{
+  /* There are no labels that could not be targeted with 'break' jumps */
+  JERRY_ASSERT (tgt_oc != MAX_OPCODES);
+  JERRY_ASSERT (outermost_label_p != NULL);
+
+  for (jsp_label_t *label_iter_p = label_set_p;
+       label_iter_p != outermost_label_p->next_label_p;
+       label_iter_p = label_iter_p->next_label_p)
+  {
+    JERRY_ASSERT (label_iter_p != NULL);
+    JERRY_ASSERT (label_iter_p->continue_tgt_oc == MAX_OPCODES);
+
+    label_iter_p->continue_tgt_oc = tgt_oc;
+  }
+} /* jsp_label_setup_continue_target */
+
+/**
+ * Mark current label, if any, as nested jumpable border
+ */
+void
+jsp_label_raise_nested_jumpable_border (void)
+{
+  if (label_set_p != NULL)
+  {
+    JERRY_ASSERT (!label_set_p->is_nested_jumpable_border);
+    label_set_p->is_nested_jumpable_border = true;
+  }
+} /* jsp_label_raise_nested_jumpable_border */
+
+/**
+ * Unmark current label, if any, as nested jumpable border
+ */
+void
+jsp_label_remove_nested_jumpable_border (void)
+{
+  if (label_set_p != NULL)
+  {
+    JERRY_ASSERT (label_set_p->is_nested_jumpable_border);
+    label_set_p->is_nested_jumpable_border = false;
+  }
+} /* jsp_label_remove_nested_jumpable_border */
+
+/**
+ * Mask current label set to restore it later, and start new label set
+ *
+ * @return pointer to masked label set's list of labels
+ */
+jsp_label_t*
+jsp_label_mask_set (void)
+{
+  jsp_label_t *ret_p = label_set_p;
+
+  label_set_p = NULL;
+
+  return ret_p;
+} /* jsp_label_mask_set */
+
+/**
+ * Restore previously masked label set
+ *
+ * Note:
+ *      current label set should be empty
+ */
+void
+jsp_label_restore_set (jsp_label_t *masked_label_set_list_p) /**< list of labels of
+                                                              *   a masked label set */
+{
+  JERRY_ASSERT (label_set_p == NULL);
+
+  label_set_p = masked_label_set_list_p;
+} /* jsp_label_restore_set */
+
+/**
+ * @}
+ * @}
+ */

jerry-core/parser/js/jsp-label.h

@@ -0,0 +1,89 @@
+/* Copyright 2015 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.
+ */
+
+#ifndef JSP_LABEL_H
+#define JSP_LABEL_H
+
+#include "lexer.h"
+#include "opcodes.h"
+
+/** \addtogroup jsparser ECMAScript parser
+ * @{
+ *
+ * \addtogroup labels Jump labels
+ * @{
+ */
+
+/**
+ * Label types
+ */
+typedef enum
+{
+  JSP_LABEL_TYPE_NAMED = (1 << 0), /**< label for breaks and continues with identifiers */
+  JSP_LABEL_TYPE_UNNAMED_BREAKS = (1 << 1), /**< label for breaks without identifiers */
+  JSP_LABEL_TYPE_UNNAMED_CONTINUES = (1 << 2) /**< label for continues without identifiers */
+} jsp_label_type_flag_t;
+
+/**
+ * Descriptor of a jump label (See also: ECMA-262 v5, 12.12, Labelled statements)
+ *
+ * Note:
+ *      Jump instructions with target identified by some specific label,
+ *      are linked into singly-linked list.
+ *
+ *      Pointer to a next element of the list is represented with opcode counter.
+ *      stored in instructions linked into the list.
+ *
+ */
+typedef struct jsp_label_t
+{
+  jsp_label_type_flag_t type_mask; /**< label type mask */
+  token id; /**< label name (TOK_NAME), if type is LABEL_NAMED */
+  opcode_counter_t continue_tgt_oc; /**< target opcode counter for continues on the label */
+  opcode_counter_t breaks_list_oc; /**< opcode counter of first 'break' instruction in the list
+                                    *   of instructions with the target identified by the label */
+  opcode_counter_t breaks_number; /**< number of 'break' instructions in the list */
+  opcode_counter_t continues_list_oc; /**< opcode counter of first 'continue' instruction in the list
+                                       *   of instructions with the target identified by the label */
+  opcode_counter_t continues_number; /**< number of 'continue' instructions in the list */
+  jsp_label_t *next_label_p; /**< next label in current label set stack */
+  bool is_nested_jumpable_border : 1; /**< flag, indicating that this and outer labels
+                                       *   are not currently accessible with simple jumps,
+                                       *   and so should be targetted with nested jumps only */
+} jsp_label_t;
+
+extern void jsp_label_init (void);
+extern void jsp_label_finalize (void);
+
+extern void jsp_label_push (jsp_label_t *out_label_p, jsp_label_type_flag_t type_mask, token id);
+extern void jsp_label_rewrite_jumps_and_pop (jsp_label_t *label_p, opcode_counter_t break_tgt_oc);
+
+extern jsp_label_t* jsp_label_find (jsp_label_type_flag_t type_mask, token id, bool *out_is_simply_jumpable_p);
+
+extern void jsp_label_add_jump (jsp_label_t *label_p, bool is_simply_jumpable, bool is_break);
+extern void jsp_label_setup_continue_target (jsp_label_t *outermost_label_p, opcode_counter_t tgt_oc);
+
+extern void jsp_label_raise_nested_jumpable_border (void);
+extern void jsp_label_remove_nested_jumpable_border (void);
+
+extern jsp_label_t* jsp_label_mask_set (void);
+extern void jsp_label_restore_set (jsp_label_t *masked_label_set_list_p);
+
+/**
+ * @}
+ * @}
+ */
+
+#endif /* !JSP_LABEL_H */