rlgen-cd/ipgotocodegen.cpp

   1 /*
   2  *  Copyright 2001-2006 Adrian Thurston <thurston@cs.queensu.ca>
   3  *            2004 Erich Ocean <eric.ocean@ampede.com>
   4  *            2005 Alan West <alan@alanz.com>
   5  */
   6
   7 /*  This file is part of Ragel.
   8  *
   9  *  Ragel is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  Ragel is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with Ragel; if not, write to the Free Software
  21  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #include "rlgen-cd.h"
  25 #include "ipgotocodegen.h"
  26 #include "redfsm.h"
  27 #include "gendata.h"
  28 #include "bstmap.h"
  29
  30 bool IpGotoCodeGen::useAgainLabel()
  31 {
  32         return redFsm->anyRegActionRets() ||
  33                         redFsm->anyRegActionByValControl() ||
  34                         redFsm->anyRegNextStmt();
  35 }
  36
  37 void IpGotoCodeGen::GOTO( ostream &ret, int gotoDest, bool inFinish )
  38 {
  39         ret << "{" << CTRL_FLOW() << "goto st" << gotoDest << ";}";
  40 }
  41
  42 void IpGotoCodeGen::CALL( ostream &ret, int callDest, int targState, bool inFinish )
  43 {
  44         if ( prePushExpr != 0 ) {
  45                 ret << "{";
  46                 INLINE_LIST( ret, prePushExpr, 0, false );
  47         }
  48
  49         ret << "{" << STACK() << "[" << TOP() << "++] = " << targState <<
  50                         "; " << CTRL_FLOW() << "goto st" << callDest << ";}";
  51
  52         if ( prePushExpr != 0 )
  53                 ret << "}";
  54 }
  55
  56 void IpGotoCodeGen::CALL_EXPR( ostream &ret, InlineItem *ilItem, int targState, bool inFinish )
  57 {
  58         if ( prePushExpr != 0 ) {
  59                 ret << "{";
  60                 INLINE_LIST( ret, prePushExpr, 0, false );
  61         }
  62
  63         ret << "{" << STACK() << "[" << TOP() << "++] = " << targState << "; " << CS() << " = (";
  64         INLINE_LIST( ret, ilItem->children, 0, inFinish );
  65         ret << "); " << CTRL_FLOW() << "goto _again;}";
  66
  67         if ( prePushExpr != 0 )
  68                 ret << "}";
  69 }
  70
  71 void IpGotoCodeGen::RET( ostream &ret, bool inFinish )
  72 {
  73         ret << "{" << CS() << " = " << STACK() << "[--" << TOP() << "];";
  74
  75         if ( postPopExpr != 0 ) {
  76                 ret << "{";
  77                 INLINE_LIST( ret, postPopExpr, 0, false );
  78                 ret << "}";
  79         }
  80
  81         ret << CTRL_FLOW() << "goto _again;}";
  82 }
  83
  84 void IpGotoCodeGen::GOTO_EXPR( ostream &ret, InlineItem *ilItem, bool inFinish )
  85 {
  86         ret << "{" << CS() << " = (";
  87         INLINE_LIST( ret, ilItem->children, 0, inFinish );
  88         ret << "); " << CTRL_FLOW() << "goto _again;}";
  89 }
  90
  91 void IpGotoCodeGen::NEXT( ostream &ret, int nextDest, bool inFinish )
  92 {
  93         ret << CS() << " = " << nextDest << ";";
  94 }
  95
  96 void IpGotoCodeGen::NEXT_EXPR( ostream &ret, InlineItem *ilItem, bool inFinish )
  97 {
  98         ret << CS() << " = (";
  99         INLINE_LIST( ret, ilItem->children, 0, inFinish );
 100         ret << ");";
 101 }
 102
 103 void IpGotoCodeGen::CURS( ostream &ret, bool inFinish )
 104 {
 105         ret << "(_ps)";
 106 }
 107
 108 void IpGotoCodeGen::TARGS( ostream &ret, bool inFinish, int targState )
 109 {
 110         ret << targState;
 111 }
 112
 113 void IpGotoCodeGen::BREAK( ostream &ret, int targState )
 114 {
 115         outLabelUsed = true;
 116         ret << "{" << P() << "++; " << CS() << " = " << targState <<
 117                         "; " << CTRL_FLOW() << "goto _out;}";
 118 }
 119
 120 bool IpGotoCodeGen::IN_TRANS_ACTIONS( RedStateAp *state )
 121 {
 122         bool anyWritten = false;
 123
 124         /* Emit any transitions that have actions and that go to this state. */
 125         for ( int it = 0; it < state->numInTrans; it++ ) {
 126                 RedTransAp *trans = state->inTrans[it];
 127                 if ( trans->action != 0 && trans->labelNeeded ) {
 128                         /* Remember that we wrote an action so we know to write the
 129                          * line directive for going back to the output. */
 130                         anyWritten = true;
 131
 132                         /* Write the label for the transition so it can be jumped to. */
 133                         out << "tr" << trans->id << ":\n";
 134
 135                         /* If the action contains a next, then we must preload the current
 136                          * state since the action may or may not set it. */
 137                         if ( trans->action->anyNextStmt() )
 138                                 out << "        " << CS() << " = " << trans->targ->id << ";\n";
 139
 140                         /* Write each action in the list. */
 141                         for ( ActionTable::Iter item = trans->action->key; item.lte(); item++ )
 142                                 ACTION( out, item->value, trans->targ->id, false );
 143
 144                         /* If the action contains a next then we need to reload, otherwise
 145                          * jump directly to the target state. */
 146                         if ( trans->action->anyNextStmt() )
 147                                 out << "\tgoto _again;\n";
 148                         else
 149                                 out << "\tgoto st" << trans->targ->id << ";\n";
 150                 }
 151         }
 152
 153         return anyWritten;
 154 }
 155
 156 /* Called from GotoCodeGen::STATE_GOTOS just before writing the gotos for each
 157  * state. */
 158 void IpGotoCodeGen::GOTO_HEADER( RedStateAp *state )
 159 {
 160         bool anyWritten = IN_TRANS_ACTIONS( state );
 161
 162         if ( state->labelNeeded )
 163                 out << "st" << state->id << ":\n";
 164
 165         if ( state->toStateAction != 0 ) {
 166                 /* Remember that we wrote an action. Write every action in the list. */
 167                 anyWritten = true;
 168                 for ( ActionTable::Iter item = state->toStateAction->key; item.lte(); item++ )
 169                         ACTION( out, item->value, state->id, false );
 170         }
 171
 172         /* Advance and test buffer pos. */
 173         if ( state->labelNeeded ) {
 174                 if ( hasEnd ) {
 175                         out <<
 176                                 "       if ( ++" << P() << " == " << PE() << " )\n"
 177                                 "               goto _test_eof" << state->id << ";\n";
 178                 }
 179                 else {
 180                         out <<
 181                                 "       " << P() << " += 1;\n";
 182                 }
 183         }
 184
 185         /* Give the state a switch case. */
 186         out << "case " << state->id << ":\n";
 187
 188         if ( state->fromStateAction != 0 ) {
 189                 /* Remember that we wrote an action. Write every action in the list. */
 190                 anyWritten = true;
 191                 for ( ActionTable::Iter item = state->fromStateAction->key; item.lte(); item++ )
 192                         ACTION( out, item->value, state->id, false );
 193         }
 194
 195         if ( anyWritten )
 196                 genLineDirective( out );
 197
 198         /* Record the prev state if necessary. */
 199         if ( state->anyRegCurStateRef() )
 200                 out << "        _ps = " << state->id << ";\n";
 201 }
 202
 203 void IpGotoCodeGen::STATE_GOTO_ERROR()
 204 {
 205         /* In the error state we need to emit some stuff that usually goes into
 206          * the header. */
 207         RedStateAp *state = redFsm->errState;
 208         bool anyWritten = IN_TRANS_ACTIONS( state );
 209
 210         /* No case label needed since we don't switch on the error state. */
 211         if ( anyWritten )
 212                 genLineDirective( out );
 213
 214         if ( state->labelNeeded )
 215                 out << "st" << state->id << ":\n";
 216
 217         /* Break out here. */
 218         outLabelUsed = true;
 219         out << CS() << " = " << state->id << ";\n";
 220         out << "        goto _out;\n";
 221 }
 222
 223
 224 /* Emit the goto to take for a given transition. */
 225 std::ostream &IpGotoCodeGen::TRANS_GOTO( RedTransAp *trans, int level )
 226 {
 227         if ( trans->action != 0 ) {
 228                 /* Go to the transition which will go to the state. */
 229                 out << TABS(level) << "goto tr" << trans->id << ";";
 230         }
 231         else {
 232                 /* Go directly to the target state. */
 233                 out << TABS(level) << "goto st" << trans->targ->id << ";";
 234         }
 235         return out;
 236 }
 237
 238 std::ostream &IpGotoCodeGen::EXIT_STATES()
 239 {
 240         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 241                 if ( st->outNeeded ) {
 242                         testEofUsed = true;
 243                         out << "        _test_eof" << st->id << ": " << CS() << " = " <<
 244                                         st->id << "; goto _test_eof; \n";
 245                 }
 246         }
 247         return out;
 248 }
 249
 250 std::ostream &IpGotoCodeGen::AGAIN_CASES()
 251 {
 252         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 253                 out <<
 254                         "               case " << st->id << ": goto st" << st->id << ";\n";
 255         }
 256         return out;
 257 }
 258
 259 std::ostream &IpGotoCodeGen::FINISH_CASES()
 260 {
 261         bool anyWritten = false;
 262
 263         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 264                 if ( st->eofAction != 0 ) {
 265                         if ( st->eofAction->eofRefs == 0 )
 266                                 st->eofAction->eofRefs = new IntSet;
 267                         st->eofAction->eofRefs->insert( st->id );
 268                 }
 269         }
 270
 271         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 272                 if ( st->eofTrans != 0 )
 273                         out << "        case " << st->id << ": goto tr" << st->eofTrans->id << ";\n";
 274         }
 275
 276         for ( ActionTableMap::Iter act = redFsm->actionMap; act.lte(); act++ ) {
 277                 if ( act->eofRefs != 0 ) {
 278                         for ( IntSet::Iter pst = *act->eofRefs; pst.lte(); pst++ )
 279                                 out << "        case " << *pst << ": \n";
 280
 281                         /* Remember that we wrote a trans so we know to write the
 282                          * line directive for going back to the output. */
 283                         anyWritten = true;
 284
 285                         /* Write each action in the eof action list. */
 286                         for ( ActionTable::Iter item = act->key; item.lte(); item++ )
 287                                 ACTION( out, item->value, STATE_ERR_STATE, true );
 288                         out << "\tbreak;\n";
 289                 }
 290         }
 291
 292         if ( anyWritten )
 293                 genLineDirective( out );
 294         return out;
 295 }
 296
 297 void IpGotoCodeGen::setLabelsNeeded( InlineList *inlineList )
 298 {
 299         for ( InlineList::Iter item = *inlineList; item.lte(); item++ ) {
 300                 switch ( item->type ) {
 301                 case InlineItem::Goto: case InlineItem::Call: {
 302                         /* Mark the target as needing a label. */
 303                         item->targState->labelNeeded = true;
 304                         break;
 305                 }
 306                 default: break;
 307                 }
 308
 309                 if ( item->children != 0 )
 310                         setLabelsNeeded( item->children );
 311         }
 312 }
 313
 314 /* Set up labelNeeded flag for each state. */
 315 void IpGotoCodeGen::setLabelsNeeded()
 316 {
 317         /* If we use the _again label, then we the _again switch, which uses all
 318          * labels. */
 319         if ( useAgainLabel() ) {
 320                 for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ )
 321                         st->labelNeeded = true;
 322         }
 323         else {
 324                 /* Do not use all labels by default, init all labelNeeded vars to false. */
 325                 for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ )
 326                         st->labelNeeded = false;
 327
 328                 /* Walk all transitions and set only those that have targs. */
 329                 for ( TransApSet::Iter trans = redFsm->transSet; trans.lte(); trans++ ) {
 330                         /* If there is no action with a next statement, then the label will be
 331                          * needed. */
 332                         if ( trans->action == 0 || !trans->action->anyNextStmt() )
 333                                 trans->targ->labelNeeded = true;
 334
 335                         /* Need labels for states that have goto or calls in action code
 336                          * invoked on characters (ie, not from out action code). */
 337                         if ( trans->action != 0 ) {
 338                                 /* Loop the actions. */
 339                                 for ( ActionTable::Iter act = trans->action->key; act.lte(); act++ ) {
 340                                         /* Get the action and walk it's tree. */
 341                                         setLabelsNeeded( act->value->inlineList );
 342                                 }
 343                         }
 344                 }
 345         }
 346
 347         if ( hasEnd ) {
 348                 for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 349                         if ( st != redFsm->errState )
 350                                 st->outNeeded = st->labelNeeded;
 351                 }
 352         }
 353 }
 354
 355 void IpGotoCodeGen::writeData()
 356 {
 357         STATE_IDS();
 358 }
 359
 360 void IpGotoCodeGen::writeExec()
 361 {
 362         /* Must set labels immediately before writing because we may depend on the
 363          * noend write option. */
 364         setLabelsNeeded();
 365         testEofUsed = false;
 366         outLabelUsed = false;
 367
 368         out << "        {\n";
 369
 370         if ( redFsm->anyRegCurStateRef() )
 371                 out << "        int _ps = 0;\n";
 372
 373         if ( redFsm->anyConditions() )
 374                 out << "        " << WIDE_ALPH_TYPE() << " _widec;\n";
 375
 376         if ( hasEnd ) {
 377                 testEofUsed = true;
 378                 out <<
 379                         "       if ( " << P() << " == " << PE() << " )\n"
 380                         "               goto _test_eof;\n";
 381         }
 382
 383         if ( useAgainLabel() ) {
 384                 out <<
 385                         "       goto _resume;\n"
 386                         "\n"
 387                         "_again:\n"
 388                         "       switch ( " << CS() << " ) {\n";
 389                         AGAIN_CASES() <<
 390                         "       default: break;\n"
 391                         "       }\n"
 392                         "\n";
 393
 394                 if ( hasEnd ) {
 395                         testEofUsed = true;
 396                         out <<
 397                                 "       if ( ++" << P() << " == " << PE() << " )\n"
 398                                 "               goto _test_eof;\n";
 399                 }
 400                 else {
 401                         out <<
 402                                 "       " << P() << " += 1;\n";
 403                 }
 404
 405                 out << "_resume:\n";
 406         }
 407
 408         out <<
 409                 "       switch ( " << CS() << " )\n     {\n";
 410                 STATE_GOTOS();
 411                 SWITCH_DEFAULT() <<
 412                 "       }\n";
 413                 EXIT_STATES() <<
 414                 "\n";
 415
 416         if ( testEofUsed )
 417                 out << "        _test_eof: {}\n";
 418
 419         if ( redFsm->anyEofTrans() || redFsm->anyEofActions() ) {
 420                 out <<
 421                         "       if ( " << P() << " == " << EOFV() << " )\n"
 422                         "       {\n"
 423                         "       switch ( " << CS() << " ) {\n";
 424                         FINISH_CASES();
 425                         SWITCH_DEFAULT() <<
 426                         "       }\n"
 427                         "       }\n"
 428                         "\n";
 429         }
 430
 431         if ( outLabelUsed )
 432                 out << "        _out: {}\n";
 433
 434         out <<
 435                 "       }\n";
 436 }