Implement seeking in the pre-scanner info. (#3126)

After changing the lexing position, the current
position of the scanner info must be moved as well.

Fixes #3101
Fixes #3102

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/parser/js/js-lexer.h

@@ -300,17 +300,6 @@ typedef struct
   uint8_t has_escape;                        /**< has escape sequences */
 } lexer_lit_location_t;
 
-/**
- * Range of input string which processing is postponed.
- */
-typedef struct
-{
-  const uint8_t *source_p;                   /**< next source byte */
-  const uint8_t *source_end_p;               /**< last source byte */
-  parser_line_counter_t line;                /**< token start line */
-  parser_line_counter_t column;              /**< token start column */
-} lexer_range_t;
-
 /**
  * Lexer token.
  */

jerry-core/parser/js/js-parser-internal.h

@@ -369,6 +369,8 @@ typedef struct
   /* Scanner members. */
   scanner_info_t *next_scanner_info_p;        /**< next scanner info block */
   scanner_info_t *active_scanner_info_p;      /**< currently active scanner info block */
+  scanner_info_t *skipped_scanner_info_p;     /**< next scanner info block */
+  scanner_info_t *skipped_scanner_info_end_p; /**< currently active scanner info block */
 
   /* Compact byte code members. */
   cbc_argument_t last_cbc;                    /**< argument of the last cbc */
@@ -566,6 +568,7 @@ void scanner_release_next (parser_context_t *context_p, size_t size);
 void scanner_set_active (parser_context_t *context_p);
 void scanner_release_active (parser_context_t *context_p, size_t size);
 void scanner_release_switch_cases (scanner_case_info_t *case_p);
+void scanner_seek (parser_context_t *context_p);
 void scanner_reverse_info_list (parser_context_t *context_p);
 void scanner_cleanup (parser_context_t *context_p);
 

jerry-core/parser/js/js-parser-statm.c

@@ -230,33 +230,6 @@ parser_statement_length (uint8_t type) /**< type of statement */
   return statement_lengths[type - PARSER_STATEMENT_BLOCK];
 } /* parser_statement_length */
 
-/**
- * Initialize a range from the current location.
- */
-static inline void
-parser_save_range (parser_context_t *context_p, /**< context */
-                   lexer_range_t *range_p, /**< destination range */
-                   const uint8_t *source_end_p) /**< source end */
-{
-  range_p->source_p = context_p->source_p;
-  range_p->source_end_p = source_end_p;
-  range_p->line = context_p->line;
-  range_p->column = context_p->column;
-} /* parser_save_range */
-
-/**
- * Set the current location on the stack.
- */
-static inline void
-parser_set_range (parser_context_t *context_p, /**< context */
-                  lexer_range_t *range_p) /**< destination range */
-{
-  context_p->source_p = range_p->source_p;
-  context_p->source_end_p = range_p->source_end_p;
-  context_p->line = range_p->line;
-  context_p->column = range_p->column;
-} /* parser_set_range */
-
 /**
  * Initialize stack iterator.
  */
@@ -802,6 +775,7 @@ parser_parse_while_statement_start (parser_context_t *context_p) /**< context */
 
   scanner_set_location (context_p, &((scanner_location_info_t *) context_p->next_scanner_info_p)->location);
   scanner_release_next (context_p, sizeof (scanner_location_info_t));
+  scanner_seek (context_p);
   lexer_next_token (context_p);
 
   loop.branch_list_p = NULL;
@@ -841,6 +815,7 @@ parser_parse_while_statement_end (parser_context_t *context_p) /**< context */
   parser_set_continues_to_current_position (context_p, loop.branch_list_p);
 
   scanner_set_location (context_p, &while_statement.condition_location);
+  scanner_seek (context_p);
   lexer_next_token (context_p);
 
   parser_parse_expression (context_p, PARSE_EXPR);
@@ -868,6 +843,7 @@ parser_parse_while_statement_end (parser_context_t *context_p) /**< context */
   parser_set_breaks_to_current_position (context_p, loop.branch_list_p);
 
   scanner_set_location (context_p, &location);
+  scanner_seek (context_p);
   context_p->token = current_token;
 } /* parser_parse_while_statement_end */
 
@@ -936,8 +912,7 @@ parser_parse_for_statement_start (parser_context_t *context_p) /**< context */
   if (context_p->next_scanner_info_p->source_p == context_p->source_p)
   {
     parser_for_in_of_statement_t for_in_of_statement;
-    scanner_location_t start_location;
-    lexer_range_t end_range;
+    scanner_location_t start_location, end_location;
 
 #if ENABLED (JERRY_ES2015_FOR_OF)
     JERRY_ASSERT (context_p->next_scanner_info_p->type == SCANNER_TYPE_FOR_IN
@@ -956,7 +931,7 @@ parser_parse_for_statement_start (parser_context_t *context_p) /**< context */
     const uint8_t *source_end_p = context_p->source_p - 2;
 
     scanner_release_next (context_p, sizeof (scanner_location_info_t));
-
+    scanner_seek (context_p);
     lexer_next_token (context_p);
     parser_parse_expression (context_p, PARSE_EXPR);
 
@@ -980,9 +955,12 @@ parser_parse_for_statement_start (parser_context_t *context_p) /**< context */
     for_in_of_statement.start_offset = context_p->byte_code_size;
 
     /* The expression parser must not read the 'in' or 'of' tokens. */
-    parser_save_range (context_p, &end_range, context_p->source_end_p);
+    scanner_get_location (&end_location, context_p);
     scanner_set_location (context_p, &start_location);
+
+    const uint8_t *original_source_end_p = context_p->source_end_p;
     context_p->source_end_p = source_end_p;
+    scanner_seek (context_p);
     lexer_next_token (context_p);
 
     if (context_p->token.type == LEXER_KEYW_VAR)
@@ -1046,7 +1024,8 @@ parser_parse_for_statement_start (parser_context_t *context_p) /**< context */
     }
 
     parser_flush_cbc (context_p);
-    parser_set_range (context_p, &end_range);
+    scanner_set_location (context_p, &end_location);
+    context_p->source_end_p = original_source_end_p;
     lexer_next_token (context_p);
 
     loop.branch_list_p = NULL;
@@ -1117,6 +1096,7 @@ parser_parse_for_statement_start (parser_context_t *context_p) /**< context */
 
   scanner_set_location (context_p, &for_info_p->end_location);
   scanner_release_next (context_p, sizeof (parser_for_statement_t));
+  scanner_seek (context_p);
   lexer_next_token (context_p);
 
   loop.branch_list_p = NULL;
@@ -1153,6 +1133,7 @@ parser_parse_for_statement_end (parser_context_t *context_p) /**< context */
   current_token = context_p->token;
 
   scanner_set_location (context_p, &for_statement.expression_location);
+  scanner_seek (context_p);
   lexer_next_token (context_p);
 
   parser_set_continues_to_current_position (context_p, loop.branch_list_p);
@@ -1170,6 +1151,7 @@ parser_parse_for_statement_end (parser_context_t *context_p) /**< context */
   parser_set_branch_to_current_position (context_p, &for_statement.branch);
 
   scanner_set_location (context_p, &for_statement.condition_location);
+  scanner_seek (context_p);
   lexer_next_token (context_p);
 
   if (context_p->token.type != LEXER_SEMICOLON)
@@ -1205,6 +1187,7 @@ parser_parse_for_statement_end (parser_context_t *context_p) /**< context */
   parser_set_breaks_to_current_position (context_p, loop.branch_list_p);
 
   scanner_set_location (context_p, &location);
+  scanner_seek (context_p);
   context_p->token = current_token;
 } /* parser_parse_for_statement_end */
 
@@ -1283,9 +1266,9 @@ parser_parse_switch_statement_start (parser_context_t *context_p) /**< context *
   do
   {
     scanner_set_location (context_p, &case_info_p->location);
+    scanner_seek (context_p);
     case_info_p = case_info_p->next_p;
 
-
     /* The last letter of case and default is 'e' and 't' respectively.  */
     JERRY_ASSERT (context_p->source_p[-1] == LIT_CHAR_LOWERCASE_E
                   || context_p->source_p[-1] == LIT_CHAR_LOWERCASE_T);
@@ -1376,6 +1359,7 @@ parser_parse_switch_statement_start (parser_context_t *context_p) /**< context *
   scanner_release_active (context_p, sizeof (scanner_switch_info_t));
 
   scanner_set_location (context_p, &start_location);
+  scanner_seek (context_p);
   lexer_next_token (context_p);
 } /* parser_parse_switch_statement_start */
 
@@ -1561,6 +1545,7 @@ parser_parse_case_statement (parser_context_t *context_p) /**< context */
 
   scanner_set_location (context_p, &((scanner_location_info_t *) context_p->next_scanner_info_p)->location);
   scanner_release_next (context_p, sizeof (scanner_location_info_t));
+  scanner_seek (context_p);
   lexer_next_token (context_p);
 
   parser_stack_iterator_init (context_p, &iterator);
@@ -1954,8 +1939,8 @@ parser_parse_export_statement (parser_context_t *context_p) /**< context */
   {
     case LEXER_KEYW_DEFAULT:
     {
-      lexer_range_t range;
-      parser_save_range (context_p, &range, context_p->source_end_p);
+      scanner_location_t location;
+      scanner_get_location (&location, context_p);
 
       context_p->status_flags |= PARSER_MODULE_STORE_IDENT;
 
@@ -1973,7 +1958,7 @@ parser_parse_export_statement (parser_context_t *context_p) /**< context */
       else
       {
         /* Assignment expression */
-        parser_set_range (context_p, &range);
+        scanner_set_location (context_p, &location);
 
         /* 15.2.3.5 Use the synthetic name '*default*' as the identifier. */
         lexer_construct_literal_object (context_p,

jerry-core/parser/js/js-parser.c

@@ -2436,6 +2436,8 @@ parser_parse_source (const uint8_t *arg_list_p, /**< function argument list */
   scanner_info_end.type = SCANNER_TYPE_END;
   context.next_scanner_info_p = &scanner_info_end;
   context.active_scanner_info_p = NULL;
+  context.skipped_scanner_info_p = NULL;
+  context.skipped_scanner_info_end_p = NULL;
 
   context.last_cbc_opcode = PARSER_CBC_UNAVAILABLE;
 

jerry-core/parser/js/js-scanner-util.c

@@ -134,7 +134,7 @@ scanner_release_next (parser_context_t *context_p, /**< context */
  * Set the active scanner info to the next scanner info.
  */
 inline void JERRY_ATTR_ALWAYS_INLINE
-scanner_set_active (parser_context_t *context_p)
+scanner_set_active (parser_context_t *context_p) /**< context */
 {
   scanner_info_t *scanner_info_p = context_p->next_scanner_info_p;
 
@@ -156,6 +156,9 @@ scanner_release_active (parser_context_t *context_p, /**< context */
   context_p->active_scanner_info_p = next_p;
 } /* scanner_release_active */
 
+/**
+ * Release switch cases.
+ */
 void
 scanner_release_switch_cases (scanner_case_info_t *case_p) /**< case list */
 {
@@ -168,6 +171,60 @@ scanner_release_switch_cases (scanner_case_info_t *case_p) /**< case list */
   }
 } /* scanner_release_switch_cases */
 
+/**
+ * Seek to correct position in the scanner info list.
+ */
+void
+scanner_seek (parser_context_t *context_p) /**< context */
+{
+  const uint8_t *source_p = context_p->source_p;
+  scanner_info_t *prev_p;
+
+  if (context_p->skipped_scanner_info_p != NULL)
+  {
+    JERRY_ASSERT (context_p->skipped_scanner_info_p->source_p != NULL);
+
+    context_p->skipped_scanner_info_end_p->next_p = context_p->next_scanner_info_p;
+
+    if (context_p->skipped_scanner_info_end_p->source_p <= source_p)
+    {
+      prev_p = context_p->skipped_scanner_info_end_p;
+    }
+    else
+    {
+      prev_p = context_p->skipped_scanner_info_p;
+
+      if (prev_p->source_p > source_p)
+      {
+        context_p->next_scanner_info_p = prev_p;
+        context_p->skipped_scanner_info_p = NULL;
+        return;
+      }
+
+      context_p->skipped_scanner_info_p = prev_p;
+    }
+  }
+  else
+  {
+    prev_p = context_p->next_scanner_info_p;
+
+    if (prev_p->source_p == NULL || prev_p->source_p > source_p)
+    {
+      return;
+    }
+
+    context_p->skipped_scanner_info_p = prev_p;
+  }
+
+  while (prev_p->next_p->source_p != NULL && prev_p->next_p->source_p <= source_p)
+  {
+    prev_p = prev_p->next_p;
+  }
+
+  context_p->skipped_scanner_info_end_p = prev_p;
+  context_p->next_scanner_info_p = prev_p->next_p;
+} /* scanner_seek */
+
 /**
  * Reverse the scanner info chain after the scanning is completed.
  */
@@ -203,6 +260,13 @@ scanner_reverse_info_list (parser_context_t *context_p) /**< context */
 void
 scanner_cleanup (parser_context_t *context_p) /**< context */
 {
+  if (context_p->skipped_scanner_info_p != NULL)
+  {
+    context_p->skipped_scanner_info_end_p->next_p = context_p->next_scanner_info_p;
+    context_p->next_scanner_info_p = context_p->skipped_scanner_info_p;
+    context_p->skipped_scanner_info_p = NULL;
+  }
+
   scanner_info_t *scanner_info_p = context_p->next_scanner_info_p;
 
   while (scanner_info_p != NULL)

tests/jerry/fail/regression-test-issue-3101.js

@@ -0,0 +1,17 @@
+// 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.
+
+for ( ; ; ( ) => 0) {
+    for ( ; $; $) ;
+}

tests/jerry/fail/regression-test-issue-3102.js

@@ -0,0 +1,17 @@
+// 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.
+
+while ( $(($) => {}) ) {
+    while ($);
+}

tests/jerry/prescanner.js

@@ -0,0 +1,52 @@
+// 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.
+
+var a = 0;
+var count = 0;
+while ( function() { while (++a < 0) ; } (), a < 4) {
+  while (++count < 0) ;
+}
+assert(count == 3);
+
+for (a = 0, count = 0; function() { while (++a < 0) ; } (), a < 4 ; ) {
+  while (++count < 0) ;
+}
+assert(count == 3);
+
+a = 0;
+count = 0;
+switch (100) {
+  default:
+    while (++a < 2) ;
+    break;
+
+  case (function () { for (var a = 0; a <= 1; a++) count ++; return a; })():
+    while (++a < 100) ;
+    break;
+
+  case (function () { for (var a = 0; a <= 2; a++) count ++; return a; })():
+    while (++a < 100) ;
+    break;
+
+  case (function () { for (var a = 0; a <= 3; a++) count ++; return a; })():
+    while (++a < 100) ;
+    break;
+
+  case (function () { for (var a = 0; a <= 4; a++) count ++; return a; })():
+    while (++a < 100) ;
+    break;
+}
+
+assert (count == 14);
+assert (a == 2);