Experimental parser: revert read_cursor

tools/lexer_generator/code_generator.jinja

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 16 matching lines @@
 
 {%- macro jump(id) -%}
   {%- set node = jump_table[id] -%}
   goto {{ node[1] ~ '_' ~ node[0] }};
 {%- endmacro -%}
 
 {%- macro do_key(key) -%}
   {%- for r in key -%}
     {%- if not loop.first %} || {% endif -%}
     {%- if r[0] == 'PRIMARY_RANGE' -%}
-      {%- if r[1][0] == r[1][1] -%}
+      {%- if r[1][0] == r[1][1] and r[1][0] != 0 -%}
         primary_char == {{r[1][0]}}
+      {%- elif r[1][0] == r[1][1] -%}
+        (primary_char == 0 && cursor_ < buffer_end_)
       {%- elif r[1][0] == 0 -%}
         primary_char <= {{r[1][1]}}
       {%- elif r[1][1] == upper_bound and not encoding == 'utf16'-%}
         primary_char >= {{r[1][0]}}
       {%- else -%}
         ({{r[1][0]}} <= primary_char && primary_char <= {{r[1][1]}})
       {%- endif -%}
     {# These classes require long_char and to be outside the primary range #}
     {%- elif r[0] == 'LONG_CHAR_CLASS' and encoding in ['utf16', 'utf8'] -%}
       {%- if r[1] == 'byte_order_mark' -%}
@@ skipping 173 matching lines @@
     {{ dispatch_entry_action(entry_action[0], entry_action[1]) }}
   {%- endif %}
 
   {{ write_label('after_entry_code', node_number) }}
 
   {%- if debug_print %}
     fprintf(stderr, "char at hand is %c (%d)\n", primary_char, primary_char);
   {% endif -%}
 
   {%- macro do_transition(jump_id) -%}
+    {%- set transition_state_id = jump_table[jump_id][0] -%}
+    {%- set inline_transition = jump_table[jump_id][1] == 'inline' %}
     FORWARD();
-    if (cursor_ < buffer_end_) {
-      {%- set transition_state_id = jump_table[jump_id][0] -%}
-      {%- set inline_transition = jump_table[jump_id][1] == 'inline' %}
-      {%- if inline_transition %}
-        {{ do_dfa_state(transition_state_id) }}
-      {% else %}
-        {{ jump(jump_id) }}
-      {% endif %}
-    }
-    {% if 'eos' in state['unique_transitions'] -%}
-      {{ jump(state['unique_transitions']['eos']) }} // eos handler
-    {%- else -%}
-      BACKWARD(1);
-      {{ jump(state['jump_before_match']) }} // no eos handler
-    {%- endif %}
+    {%- if inline_transition %}
+      {{ do_dfa_state(transition_state_id) }}
+    {% else %}
+      {{ jump(jump_id) }}
+    {% endif %}
   {%- endmacro -%}
 
   {%- if state['switch_transitions'] -%}
     switch(primary_char) {
     {%- for ranges, jump_id in state['switch_transitions'] %}
       {%- for r in ranges -%}
         {%- for key in range(r[0], r[1] + 1) -%}
           case {{key}}:
         {% endfor %}
       {%- endfor -%}
       {{ do_transition(jump_id) }}
     {% endfor -%}
     }
   {%- endif -%}
 
   {%- for key, jump_id in state['if_transitions'] %}
     if ({{do_key(key)}}) { // normal if transition
       {{ do_transition(jump_id) }}
     }
   {% endfor -%}
 
-  {%- if state['deferred_transitions'] -%}
+  {%- if 'eos' in state['unique_transitions'] %}
+    if (primary_char == 0 && cursor_ >= buffer_end_) { // eos handler
+      {{ jump(state['unique_transitions']['eos']) }}
+    }
+  {%- endif -%}
+
+  {%- if state['deferred_transitions'] %}
     if ({{long_char_check()}}) {
       next_.is_onebyte = false;
       {{long_char_create()}}
       {%- for key, jump_id in state['deferred_transitions'] %}
         if ({{do_key(key)}}) { // long_char transition
           {{ do_transition(jump_id) }}
         }
       {% endfor -%}
     }
-  {%- endif-%}
-
-  {{ write_label('before_match', node_number) }}
+  {%- endif -%}
 
   {%- set match_action = state.match_action -%}
   {%- if match_action %}
     {{ dispatch_match_action(match_action[0], match_action[1]) }}
     CRASH();
   {% else %}
     goto default_action;
   {%- endif %}
 
 {%- endmacro %}
@@ skipping 13 matching lines @@
 
 #define FORWARD() {                               \
   cursor_++;                                      \
 }
 
 #define BACKWARD(n) {                             \
   cursor_ -= n;                                   \
 }
 
 #define READ_CURSOR() {                           \
-  ASSERT(cursor_ < buffer_end_);                  \
-  primary_char = *(cursor_);                      \
+  if (cursor_ >= buffer_end_) primary_char = 0;   \
+  else primary_char = *(cursor_);                 \
 }
 
 #ifdef DEBUG
 #define CRASH() { ((void(*)())0)(); }
 #else
 #define CRASH() { }
 #endif
 
 namespace v8 {
 namespace internal {
@@ skipping 26 matching lines @@
     // force use of stored_token
     stored_token = Token::ILLEGAL;
     // force use of marker
     marker = NULL;
     // force use of state_entry_0
     goto state_entry_0;
   }
 }
 } }