rlgen-csharp/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-csharp.h"
  25 #include "ipgotocodegen.h"
  26 #include "redfsm.h"
  27 #include "gendata.h"
  28 #include "bstmap.h"
  29
  30 bool CSharpIpGotoCodeGen::useAgainLabel()
  31 {
  32         return redFsm->anyRegActionRets() ||
  33                         redFsm->anyRegActionByValControl() ||
  34                         redFsm->anyRegNextStmt();
  35 }
  36
  37 void CSharpIpGotoCodeGen::GOTO( ostream &ret, int gotoDest, bool inFinish )
  38 {
  39         ret << "{" << CTRL_FLOW() << "goto st" << gotoDest << ";}";
  40 }
  41
  42 void CSharpIpGotoCodeGen::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 CSharpIpGotoCodeGen::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 CSharpIpGotoCodeGen::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 CSharpIpGotoCodeGen::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 CSharpIpGotoCodeGen::NEXT( ostream &ret, int nextDest, bool inFinish )
  92 {
  93         ret << CS() << " = " << nextDest << ";";
  94 }
  95
  96 void CSharpIpGotoCodeGen::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 CSharpIpGotoCodeGen::CURS( ostream &ret, bool inFinish )
 104 {
 105         ret << "(_ps)";
 106 }
 107
 108 void CSharpIpGotoCodeGen::TARGS( ostream &ret, bool inFinish, int targState )
 109 {
 110         ret << targState;
 111 }
 112
 113 void CSharpIpGotoCodeGen::BREAK( ostream &ret, int targState )
 114 {
 115         /* FIXME: If this code generator is made active then BREAK generation
 116          * needs to check csForced. */
 117         outLabelUsed = true;
 118         ret << "{" << P() << "++; " << CS() << " = " << targState <<
 119                         "; " << CTRL_FLOW() << "goto _out;}";
 120 }
 121
 122 bool CSharpIpGotoCodeGen::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
 146                         /* If the action contains a next then we need to reload, otherwise
 147                          * jump directly to the target state. */
 148                         if ( trans->action->anyNextStmt() )
 149                                 out << "\tgoto _again;\n";
 150                         else
 151                                 out << "\tgoto st" << trans->targ->id << ";\n";
 152                 }
 153         }
 154
 155         return anyWritten;
 156 }
 157
 158 /* Called from GotoCodeGen::STATE_GOTOS just before writing the gotos for each
 159  * state. */
 160 void CSharpIpGotoCodeGen::GOTO_HEADER( RedStateAp *state )
 161 {
 162         bool anyWritten = IN_TRANS_ACTIONS( state );
 163
 164         if ( state->labelNeeded )
 165                 out << "st" << state->id << ":\n";
 166
 167         if ( state->toStateAction != 0 ) {
 168                 /* Remember that we wrote an action. Write every action in the list. */
 169                 anyWritten = true;
 170                 for ( ActionTable::Iter item = state->toStateAction->key; item.lte(); item++ )
 171                         ACTION( out, item->value, state->id, false );
 172         }
 173
 174         /* Advance and test buffer pos. */
 175         if ( state->labelNeeded ) {
 176                 if ( hasEnd ) {
 177                         out <<
 178                                 "       if ( ++" << P() << " == " << PE() << " )\n"
 179                                 "               goto _test_eof" << state->id << ";\n";
 180                 }
 181                 else {
 182                         out <<
 183                                 "       " << P() << " += 1;\n";
 184                 }
 185         }
 186
 187         /* Give the state a switch case. */
 188         out << "case " << state->id << ":\n";
 189
 190         if ( state->fromStateAction != 0 ) {
 191                 /* Remember that we wrote an action. Write every action in the list. */
 192                 anyWritten = true;
 193                 for ( ActionTable::Iter item = state->fromStateAction->key; item.lte(); item++ )
 194                         ACTION( out, item->value, state->id, false );
 195         }
 196
 197         if ( anyWritten )
 198                 genLineDirective( out );
 199
 200         /* Record the prev state if necessary. */
 201         if ( state->anyRegCurStateRef() )
 202                 out << "        _ps = " << state->id << ";\n";
 203 }
 204
 205 void CSharpIpGotoCodeGen::STATE_GOTO_ERROR()
 206 {
 207         /* In the error state we need to emit some stuff that usually goes into
 208          * the header. */
 209         RedStateAp *state = redFsm->errState;
 210         bool anyWritten = IN_TRANS_ACTIONS( state );
 211
 212         /* No case label needed since we don't switch on the error state. */
 213         if ( anyWritten )
 214                 genLineDirective( out );
 215
 216         if ( state->labelNeeded )
 217                 out << "st" << state->id << ":\n";
 218
 219         /* Break out here. */
 220         outLabelUsed = true;
 221         out << CS() << " = " << state->id << ";\n";
 222         out << "        goto _out;\n";
 223 }
 224
 225
 226 /* Emit the goto to take for a given transition. */
 227 std::ostream &CSharpIpGotoCodeGen::TRANS_GOTO( RedTransAp *trans, int level )
 228 {
 229         if ( trans->action != 0 ) {
 230                 /* Go to the transition which will go to the state. */
 231                 out << TABS(level) << "goto tr" << trans->id << ";";
 232         }
 233         else {
 234                 /* Go directly to the target state. */
 235                 out << TABS(level) << "goto st" << trans->targ->id << ";";
 236         }
 237         return out;
 238 }
 239
 240 std::ostream &CSharpIpGotoCodeGen::EXIT_STATES()
 241 {
 242         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 243                 if ( st->outNeeded ) {
 244                         testEofUsed = true;
 245                         out << "        _test_eof" << st->id << ": " << CS() << " = " <<
 246                                         st->id << "; goto _test_eof; \n";
 247                 }
 248         }
 249         return out;
 250 }
 251
 252 std::ostream &CSharpIpGotoCodeGen::AGAIN_CASES()
 253 {
 254         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 255                 out <<
 256                         "               case " << st->id << ": goto st" << st->id << ";\n";
 257         }
 258         return out;
 259 }
 260
 261 std::ostream &CSharpIpGotoCodeGen::FINISH_CASES()
 262 {
 263         bool anyWritten = false;
 264
 265         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 266                 if ( st->eofAction != 0 ) {
 267                         if ( st->eofAction->eofRefs == 0 )
 268                                 st->eofAction->eofRefs = new IntSet;
 269                         st->eofAction->eofRefs->insert( st->id );
 270                 }
 271         }
 272
 273         for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 274                 if ( st->eofTrans != 0 )
 275                         out << "        case " << st->id << ": goto tr" << st->eofTrans->id << ";\n";
 276         }
 277
 278         for ( ActionTableMap::Iter act = redFsm->actionMap; act.lte(); act++ ) {
 279                 if ( act->eofRefs != 0 ) {
 280                         for ( IntSet::Iter pst = *act->eofRefs; pst.lte(); pst++ )
 281                                 out << "        case " << *pst << ": \n";
 282
 283                         /* Remember that we wrote a trans so we know to write the
 284                          * line directive for going back to the output. */
 285                         anyWritten = true;
 286
 287                         /* Write each action in the eof action list. */
 288                         for ( ActionTable::Iter item = act->key; item.lte(); item++ )
 289                                 ACTION( out, item->value, STATE_ERR_STATE, true );
 290                         out << "\tbreak;\n";
 291                 }
 292         }
 293
 294         if ( anyWritten )
 295                 genLineDirective( out );
 296         return out;
 297 }
 298
 299 void CSharpIpGotoCodeGen::setLabelsNeeded( InlineList *inlineList )
 300 {
 301         for ( InlineList::Iter item = *inlineList; item.lte(); item++ ) {
 302                 switch ( item->type ) {
 303                 case InlineItem::Goto: case InlineItem::Call: {
 304                         /* Mark the target as needing a label. */
 305                         item->targState->labelNeeded = true;
 306                         break;
 307                 }
 308                 default: break;
 309                 }
 310
 311                 if ( item->children != 0 )
 312                         setLabelsNeeded( item->children );
 313         }
 314 }
 315
 316 /* Set up labelNeeded flag for each state. */
 317 void CSharpIpGotoCodeGen::setLabelsNeeded()
 318 {
 319         /* If we use the _again label, then we the _again switch, which uses all
 320          * labels. */
 321         if ( useAgainLabel() ) {
 322                 for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ )
 323                         st->labelNeeded = true;
 324         }
 325         else {
 326                 /* Do not use all labels by default, init all labelNeeded vars to false. */
 327                 for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ )
 328                         st->labelNeeded = false;
 329
 330                 /* Walk all transitions and set only those that have targs. */
 331                 for ( TransApSet::Iter trans = redFsm->transSet; trans.lte(); trans++ ) {
 332                         /* If there is no action with a next statement, then the label will be
 333                          * needed. */
 334                         if ( trans->action == 0 || !trans->action->anyNextStmt() )
 335                                 trans->targ->labelNeeded = true;
 336
 337                         /* Need labels for states that have goto or calls in action code
 338                          * invoked on characters (ie, not from out action code). */
 339                         if ( trans->action != 0 ) {
 340                                 /* Loop the actions. */
 341                                 for ( ActionTable::Iter act = trans->action->key; act.lte(); act++ ) {
 342                                         /* Get the action and walk it's tree. */
 343                                         setLabelsNeeded( act->value->inlineList );
 344                                 }
 345                         }
 346                 }
 347         }
 348
 349         if ( hasEnd ) {
 350                 for ( RedStateList::Iter st = redFsm->stateList; st.lte(); st++ ) {
 351                         if ( st != redFsm->errState )
 352                                 st->outNeeded = st->labelNeeded;
 353                 }
 354         }
 355 }
 356
 357 void CSharpIpGotoCodeGen::writeData()
 358 {
 359         STATE_IDS();
 360 }
 361
 362 void CSharpIpGotoCodeGen::writeExec()
 363 {
 364         /* Must set labels immediately before writing because we may depend on the
 365          * noend write option. */
 366         setLabelsNeeded();
 367         testEofUsed = false;
 368         outLabelUsed = false;
 369
 370         out << "        {\n";
 371
 372         if ( redFsm->anyRegCurStateRef() )
 373                 out << "        int _ps = 0;\n";
 374
 375         if ( redFsm->anyConditions() )
 376                 out << "        " << WIDE_ALPH_TYPE() << " _widec;\n";
 377
 378         if ( hasEnd ) {
 379                 testEofUsed = true;
 380                 out <<
 381                         "       if ( " << P() << " == " << PE() << " )\n"
 382                         "               goto _test_eof;\n";
 383         }
 384
 385         if ( useAgainLabel() ) {
 386                 out <<
 387                         "       goto _resume;\n"
 388                         "\n"
 389                         "_again:\n"
 390                         "       switch ( " << CS() << " ) {\n";
 391                         AGAIN_CASES() <<
 392                         "       default: break;\n"
 393                         "       }\n"
 394                         "\n";
 395
 396                 if ( hasEnd ) {
 397                         testEofUsed = true;
 398                         out <<
 399                                 "       if ( ++" << P() << " == " << PE() << " )\n"
 400                                 "               goto _test_eof;\n";
 401                 }
 402                 else {
 403                         out <<
 404                                 "       " << P() << " += 1;\n";
 405                 }
 406
 407                 out << "_resume:\n";
 408         }
 409
 410         out <<
 411                 "       switch ( " << CS() << " )\n     {\n";
 412                 STATE_GOTOS();
 413                 SWITCH_DEFAULT() <<
 414                 "       }\n";
 415                 EXIT_STATES() <<
 416                 "\n";
 417
 418         if ( testEofUsed )
 419                 out << "        _test_eof: {}\n";
 420
 421         if ( redFsm->anyEofTrans() || redFsm->anyEofActions() ) {
 422                 out <<
 423                         "       if ( " << P() << " == " << EOFV() << " )\n"
 424                         "       {\n"
 425                         "       switch ( " << CS() << " ) {\n";
 426                         FINISH_CASES();
 427                         SWITCH_DEFAULT() <<
 428                         "       }\n"
 429                         "       }\n"
 430                         "\n";
 431         }
 432
 433         if ( outLabelUsed )
 434                 out << "        _out: {}\n";
 435
 436         out <<
 437                 "       }\n";
 438 }