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, 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, false );
  61         }
  62
  63         ret << "{" << STACK() << "[" << TOP() << "++] = " << targState << "; " << CS() << " = (";
  64         INLINE_LIST( ret, ilItem->children, 0, inFinish, false );
  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, 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, false );
  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, false );
 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, bool csForced )
 114 {
 115         outLabelUsed = true;
 116         ret << "{" << P() << "++; ";
 117         if ( !csForced )
 118                 ret << CS() << " = " << targState << "; ";
 119         ret << CTRL_FLOW() << "goto _out;}";
 120 }
 121
 122 bool IpGotoCodeGen::IN_TRANS_ACTIONS( RedStateAp *state )
 123 {
 124         bool anyWritten = false;
 125
 126         /* Emit any transitions that have actions and that go to this state. */
 127         for ( int it = 0; it < state->numInTrans; it++ ) {
 128                 RedTransAp *trans = state->inTrans[it];
 129                 if ( trans->action != 0 && trans->labelNeeded ) {
 130                         /* Remember that we wrote an action so we know to write the
 131                          * line directive for going back to the output. */
 132                         anyWritten = true;
 133
 134                         /* Write the label for the transition so it can be jumped to. */
 135                         out << "tr" << trans->id << ":\n";
 136
 137                         /* If the action contains a next, then we must preload the current
 138                          * state since the action may or may not set it. */
 139                         if ( trans->action->anyNextStmt() )
 140                                 out << "        " << CS() << " = " << trans->targ->id << ";\n";
 141
 142                         /* Write each action in the list. */
 143                         for ( ActionTable::Iter item = trans->action->key; item.lte(); item++ ) {
 144                                 ACTION( out, item->value, trans->targ->id, false,
 145                                                 trans->action->anyNextStmt() );
 146                         }
 147
 148                         /* If the action contains a next then we need to reload, otherwise
 149                          * jump directly to the target state. */
 150                         if ( trans->action->anyNextStmt() )
 151                                 out << "\tgoto _again;\n";
 152                         else
 153                                 out << "\tgoto st" << trans->targ->id << ";\n";
 154                 }
 155         }
 156
 157         return anyWritten;
 158 }
 159
 160 /* Called from GotoCodeGen::STATE_GOTOS just before writing the gotos for each
 161  * state. */
 162 void IpGotoCodeGen::GOTO_HEADER( RedStateAp *state )
 163 {
 164         bool anyWritten = IN_TRANS_ACTIONS( state );
 165
 166         if ( state->labelNeeded )
 167                 out << "st" << state->id << ":\n";
 168
 169         if ( state->toStateAction != 0 ) {
 170                 /* Remember that we wrote an action. Write every action in the list. */
 171                 anyWritten = true;
 172                 for ( ActionTable::Iter item = state->toStateAction->key; item.lte(); item++ ) {
 173                         ACTION( out, item->value, state->id, false,
 174                                         state->toStateAction->anyNextStmt() );
 175                 }
 176         }
 177
 178         /* Advance and test buffer pos. */
 179         if ( state->labelNeeded ) {
 180                 if ( hasEnd ) {
 181                         out <<
 182                                 "       if ( ++" << P() << " == " << PE() << " )\n"
 183                                 "               goto _test_eof" << state->id << ";\n";
 184                 }
 185                 else {
 186                         out <<
 187                                 "       " << P() << " += 1;\n";
 188                 }
 189         }
 190
 191         /* Give the state a switch case. */
 192         out << "case " << state->id << ":\n";
 193
 194         if ( state->fromStateAction != 0 ) {
 195                 /* Remember that we wrote an action. Write every action in the list. */
 196                 anyWritten = true;
 197                 for ( ActionTable::Iter item = state->fromStateAction->key; item.lte(); item++ ) {
 198                         ACTION( out, item->value, state->id, false,
 199                                         state->fromStateAction->anyNextStmt() );
 200                 }
 201         }
 202
 203         if ( anyWritten )
 204                 genLineDirective( out );
 205
 206         /* Record the prev state if necessary. */
 207         if ( state->anyRegCurStateRef() )
 208                 out << "        _ps = " << state->id << ";\n";
 209 }
 210
 211 void IpGotoCodeGen::STATE_GOTO_ERROR()
 212 {
 213         /* In the error state we need to emit some stuff that usually goes into
 214          * the header. */
 215         RedStateAp *state = redFsm->errState;
 216         bool anyWritten = IN_TRANS_ACTIONS( state );
 217
 218         /* No case label needed since we don't switch on the error state. */
 219         if ( anyWritten )
 220                 genLineDirective( out );
 221
 222         if ( state->labelNeeded )
 223                 out << "st" << state->id << ":\n";
 224
 225         /* Break out here. */
 226         outLabelUsed = true;
 227         out << CS() << " = " << state->id << ";\n";
 228         out << "        goto _out;\n";
 229 }
 230
 231
 232 /* Emit the goto to take for a given transition. */
 233 std::ostream &IpGotoCodeGen::TRANS_GOTO( RedTransAp *trans, int level )
 234 {
 235         if ( trans->action != 0 ) {
 236                 /* Go to the transition which will go to the state. */
 237                 out << TABS(level) << "goto tr" << trans->id << ";";
 238         }
 239         else {
 240                 /* Go directly to the target state. */
 241                 out << TABS(level) << "goto st" << trans->targ->id << ";";
 242         }
 243         return out;
 244 }
 245
 246 std::ostream &IpGotoCodeGen::EXIT_STATES()
 247 {
 248         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 249                 if ( st->outNeeded ) {
 250                         testEofUsed = true;
 251                         out << "        _test_eof" << st->id << ": " << CS() << " = " <<
 252                                         st->id << "; goto _test_eof; \n";
 253                 }
 254         }
 255         return out;
 256 }
 257
 258 std::ostream &IpGotoCodeGen::AGAIN_CASES()
 259 {
 260         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 261                 out <<
 262                         "               case " << st->id << ": goto st" << st->id << ";\n";
 263         }
 264         return out;
 265 }
 266
 267 std::ostream &IpGotoCodeGen::FINISH_CASES()
 268 {
 269         bool anyWritten = false;
 270
 271         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 272                 if ( st->eofAction != 0 ) {
 273                         if ( st->eofAction->eofRefs == 0 )
 274                                 st->eofAction->eofRefs = new IntSet;
 275                         st->eofAction->eofRefs->insert( st->id );
 276                 }
 277         }
 278
 279         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 280                 if ( st->eofTrans != 0 )
 281                         out << "        case " << st->id << ": goto tr" << st->eofTrans->id << ";\n";
 282         }
 283
 284         for ( ActionTableMap::Iter act = redFsm->actionMap; act.lte(); act++ ) {
 285                 if ( act->eofRefs != 0 ) {
 286                         for ( IntSet::Iter pst = *act->eofRefs; pst.lte(); pst++ )
 287                                 out << "        case " << *pst << ": \n";
 288
 289                         /* Remember that we wrote a trans so we know to write the
 290                          * line directive for going back to the output. */
 291                         anyWritten = true;
 292
 293                         /* Write each action in the eof action list. */
 294                         for ( ActionTable::Iter item = act->key; item.lte(); item++ )
 295                                 ACTION( out, item->value, STATE_ERR_STATE, true, false );
 296                         out << "\tbreak;\n";
 297                 }
 298         }
 299
 300         if ( anyWritten )
 301                 genLineDirective( out );
 302         return out;
 303 }
 304
 305 void IpGotoCodeGen::setLabelsNeeded( InlineList *inlineList )
 306 {
 307         for ( InlineList::Iter item = *inlineList; item.lte(); item++ ) {
 308                 switch ( item->type ) {
 309                 case InlineItem::Goto: case InlineItem::Call: {
 310                         /* Mark the target as needing a label. */
 311                         item->targState->labelNeeded = true;
 312                         break;
 313                 }
 314                 default: break;
 315                 }
 316
 317                 if ( item->children != 0 )
 318                         setLabelsNeeded( item->children );
 319         }
 320 }
 321
 322 /* Set up labelNeeded flag for each state. */
 323 void IpGotoCodeGen::setLabelsNeeded()
 324 {
 325         /* If we use the _again label, then we the _again switch, which uses all
 326          * labels. */
 327         if ( useAgainLabel() ) {
 328                 for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ )
 329                         st->labelNeeded = true;
 330         }
 331         else {
 332                 /* Do not use all labels by default, init all labelNeeded vars to false. */
 333                 for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ )
 334                         st->labelNeeded = false;
 335
 336                 /* Walk all transitions and set only those that have targs. */
 337                 for ( TransApSet::Iter trans = redFsm->transSet; trans.lte(); trans++ ) {
 338                         /* If there is no action with a next statement, then the label will be
 339                          * needed. */
 340                         if ( trans->action == 0 || !trans->action->anyNextStmt() )
 341                                 trans->targ->labelNeeded = true;
 342
 343                         /* Need labels for states that have goto or calls in action code
 344                          * invoked on characters (ie, not from out action code). */
 345                         if ( trans->action != 0 ) {
 346                                 /* Loop the actions. */
 347                                 for ( ActionTable::Iter act = trans->action->key; act.lte(); act++ ) {
 348                                         /* Get the action and walk it's tree. */
 349                                         setLabelsNeeded( act->value->inlineList );
 350                                 }
 351                         }
 352                 }
 353         }
 354
 355         if ( hasEnd ) {
 356                 for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 357                         if ( st != redFsm->errState )
 358                                 st->outNeeded = st->labelNeeded;
 359                 }
 360         }
 361 }
 362
 363 void IpGotoCodeGen::writeData()
 364 {
 365         STATE_IDS();
 366 }
 367
 368 void IpGotoCodeGen::writeExec()
 369 {
 370         /* Must set labels immediately before writing because we may depend on the
 371          * noend write option. */
 372         setLabelsNeeded();
 373         testEofUsed = false;
 374         outLabelUsed = false;
 375
 376         out << "        {\n";
 377
 378         if ( redFsm->anyRegCurStateRef() )
 379                 out << "        int _ps = 0;\n";
 380
 381         if ( redFsm->anyConditions() )
 382                 out << "        " << WIDE_ALPH_TYPE() << " _widec;\n";
 383
 384         if ( hasEnd ) {
 385                 testEofUsed = true;
 386                 out <<
 387                         "       if ( " << P() << " == " << PE() << " )\n"
 388                         "               goto _test_eof;\n";
 389         }
 390
 391         if ( useAgainLabel() ) {
 392                 out <<
 393                         "       goto _resume;\n"
 394                         "\n"
 395                         "_again:\n"
 396                         "       switch ( " << CS() << " ) {\n";
 397                         AGAIN_CASES() <<
 398                         "       default: break;\n"
 399                         "       }\n"
 400                         "\n";
 401
 402                 if ( hasEnd ) {
 403                         testEofUsed = true;
 404                         out <<
 405                                 "       if ( ++" << P() << " == " << PE() << " )\n"
 406                                 "               goto _test_eof;\n";
 407                 }
 408                 else {
 409                         out <<
 410                                 "       " << P() << " += 1;\n";
 411                 }
 412
 413                 out << "_resume:\n";
 414         }
 415
 416         out <<
 417                 "       switch ( " << CS() << " )\n     {\n";
 418                 STATE_GOTOS();
 419                 SWITCH_DEFAULT() <<
 420                 "       }\n";
 421                 EXIT_STATES() <<
 422                 "\n";
 423
 424         if ( testEofUsed )
 425                 out << "        _test_eof: {}\n";
 426
 427         if ( redFsm->anyEofTrans() || redFsm->anyEofActions() ) {
 428                 out <<
 429                         "       if ( " << P() << " == " << EOFV() << " )\n"
 430                         "       {\n"
 431                         "       switch ( " << CS() << " ) {\n";
 432                         FINISH_CASES();
 433                         SWITCH_DEFAULT() <<
 434                         "       }\n"
 435                         "       }\n"
 436                         "\n";
 437         }
 438
 439         if ( outLabelUsed )
 440                 out << "        _out: {}\n";
 441
 442         out <<
 443                 "       }\n";
 444 }