Rework RegExp engine and add support for proper unicode matching (#3746)

This change includes several bugfixes, general improvements, and support
for additional features.
- Added full support for web compatibility syntax defined in Annex B
- Implemented parsing and matching patterns in unicode mode
- Fixed capture results when iterating with nested capturing groups
- Significantly reduced regexp bytecode size
- Reduced stack usage during regexp execution
- Improved matching performance

JerryScript-DCO-1.0-Signed-off-by: Dániel Bátyai [email protected]

Author: dbatyai

jerry-core/api/jerry-snapshot.c

@@ -559,18 +559,15 @@ snapshot_load_compiled_code (const uint8_t *base_addr_p, /**< base address of th
 #if ENABLED (JERRY_BUILTIN_REGEXP)
   if (!(bytecode_p->status_flags & CBC_CODE_FLAGS_FUNCTION))
   {
-    const re_compiled_code_t *re_bytecode_p = NULL;
 
     const uint8_t *regex_start_p = ((const uint8_t *) bytecode_p) + sizeof (ecma_compiled_code_t);
 
     /* Real size is stored in refs. */
     ecma_string_t *pattern_str_p = ecma_new_ecma_string_from_utf8 (regex_start_p,
                                                                    bytecode_p->refs);
 
-    re_compile_bytecode (&re_bytecode_p,
-                         pattern_str_p,
-                         bytecode_p->status_flags);
-
+    const re_compiled_code_t *re_bytecode_p = re_compile_bytecode (pattern_str_p,
+                                                                   bytecode_p->status_flags);
     ecma_deref_ecma_string (pattern_str_p);
 
     return (ecma_compiled_code_t *) re_bytecode_p;

jerry-core/ecma/base/ecma-gc.c

@@ -1467,7 +1467,7 @@ ecma_gc_run (void)
 
 #if ENABLED (JERRY_BUILTIN_REGEXP)
   /* Free RegExp bytecodes stored in cache */
-  re_cache_gc_run ();
+  re_cache_gc ();
 #endif /* ENABLED (JERRY_BUILTIN_REGEXP) */
 } /* ecma_gc_run */
 

jerry-core/ecma/base/ecma-helpers-string.c

@@ -2362,8 +2362,7 @@ ecma_string_trim_helper (const lit_utf8_byte_t **utf8_str_p, /**< [in, out] curr
   {
     read_size = lit_read_code_unit_from_utf8 (current_p, &ch);
 
-    if (!lit_char_is_white_space (ch)
-        && !lit_char_is_line_terminator (ch))
+    if (!lit_char_is_white_space (ch))
     {
       nonws_start_p = current_p;
       break;
@@ -2378,8 +2377,7 @@ ecma_string_trim_helper (const lit_utf8_byte_t **utf8_str_p, /**< [in, out] curr
   {
     read_size = lit_read_prev_code_unit_from_utf8 (current_p, &ch);
 
-    if (!lit_char_is_white_space (ch)
-        && !lit_char_is_line_terminator (ch))
+    if (!lit_char_is_white_space (ch))
     {
       break;
     }

jerry-core/ecma/builtin-objects/ecma-builtin-global.c

@@ -223,13 +223,13 @@ ecma_builtin_global_object_decode_uri_helper (lit_utf8_byte_t *input_start_p, /*
       continue;
     }
 
-    ecma_char_t decoded_byte;
-
-    if (!lit_read_code_unit_from_hex (input_char_p + 1, 2, &decoded_byte))
+    uint32_t hex_value = lit_char_hex_lookup (input_char_p + 1, input_end_p, 2);
+    if (hex_value == UINT32_MAX)
     {
       return ecma_raise_uri_error (ECMA_ERR_MSG ("Invalid hexadecimal value."));
     }
 
+    ecma_char_t decoded_byte = (ecma_char_t) hex_value;
     input_char_p += URI_ENCODED_BYTE_SIZE;
 
     if (decoded_byte <= LIT_UTF8_1_BYTE_CODE_POINT_MAX)
@@ -272,20 +272,18 @@ ecma_builtin_global_object_decode_uri_helper (lit_utf8_byte_t *input_start_p, /*
     /* Input decode. */
     if (*input_char_p != '%')
     {
-      *output_char_p = *input_char_p;
-      output_char_p++;
-      input_char_p++;
+      *output_char_p++ = *input_char_p++;
       continue;
     }
 
-    ecma_char_t decoded_byte;
-
-    if (!lit_read_code_unit_from_hex (input_char_p + 1, 2, &decoded_byte))
+    uint32_t hex_value = lit_char_hex_lookup (input_char_p + 1, input_end_p, 2);
+    if (hex_value == UINT32_MAX)
     {
       ret_value = ecma_raise_uri_error (ECMA_ERR_MSG ("Invalid hexadecimal value."));
       break;
     }
 
+    ecma_char_t decoded_byte = (ecma_char_t) hex_value;
     input_char_p += URI_ENCODED_BYTE_SIZE;
 
     if (decoded_byte <= LIT_UTF8_1_BYTE_CODE_POINT_MAX)
@@ -337,17 +335,16 @@ ecma_builtin_global_object_decode_uri_helper (lit_utf8_byte_t *input_start_p, /*
         }
         else
         {
-          ecma_char_t chr;
+          hex_value = lit_char_hex_lookup (input_char_p + 1, input_end_p, 2);
 
-          if (!lit_read_code_unit_from_hex (input_char_p + 1, 2, &chr)
-              || ((chr & LIT_UTF8_EXTRA_BYTE_MASK) != LIT_UTF8_EXTRA_BYTE_MARKER))
+          if (hex_value == UINT32_MAX || (hex_value & LIT_UTF8_EXTRA_BYTE_MASK) != LIT_UTF8_EXTRA_BYTE_MARKER)
           {
             is_valid = false;
             break;
           }
 
-          octets[i] = (lit_utf8_byte_t) chr;
           input_char_p += URI_ENCODED_BYTE_SIZE;
+          octets[i] = (lit_utf8_byte_t) hex_value;
         }
       }
 

jerry-core/ecma/builtin-objects/ecma-builtin-json.c

@@ -174,18 +174,13 @@ ecma_builtin_json_parse_string (ecma_json_token_t *token_p) /**< token argument
         }
         case LIT_CHAR_LOWERCASE_U:
         {
-          if ((end_p - current_p <= ECMA_JSON_HEX_ESCAPE_SEQUENCE_LENGTH))
+          uint32_t hex_value = lit_char_hex_lookup (current_p + 1, end_p, ECMA_JSON_HEX_ESCAPE_SEQUENCE_LENGTH);
+          if (hex_value == UINT32_MAX)
           {
             goto invalid_string;
           }
 
-          ecma_char_t code_unit;
-          if (!(lit_read_code_unit_from_hex (current_p + 1, ECMA_JSON_HEX_ESCAPE_SEQUENCE_LENGTH, &code_unit)))
-          {
-            goto invalid_string;
-          }
-
-          ecma_stringbuilder_append_char (&result_builder, code_unit);
+          ecma_stringbuilder_append_char (&result_builder, (ecma_char_t) hex_value);
           current_p += ECMA_JSON_HEX_ESCAPE_SEQUENCE_LENGTH + 1;
           break;
         }

jerry-core/ecma/builtin-objects/ecma-builtins.c

@@ -505,12 +505,10 @@ ecma_instantiate_builtin (ecma_builtin_id_t obj_builtin_id) /**< built-in id */
 
       ext_object_p->u.class_prop.class_id = LIT_MAGIC_STRING_REGEXP_UL;
 
-      const re_compiled_code_t *bc_p = NULL;
-      ecma_value_t ret_value = re_compile_bytecode (&bc_p,
-                                                    ecma_get_magic_string (LIT_MAGIC_STRING_EMPTY_NON_CAPTURE_GROUP),
-                                                    RE_FLAG_EMPTY);
+      re_compiled_code_t *bc_p = re_compile_bytecode (ecma_get_magic_string (LIT_MAGIC_STRING_EMPTY_NON_CAPTURE_GROUP),
+                                                      RE_FLAG_EMPTY);
 
-      JERRY_ASSERT (ecma_is_value_empty (ret_value));
+      JERRY_ASSERT (bc_p != NULL);
 
       ECMA_SET_INTERNAL_VALUE_POINTER (ext_object_p->u.class_prop.u.value, bc_p);