source/programparser.cpp

   1 #include <msp/strings/format.h>
   2 #include <msp/strings/regex.h>
   3 #include "programparser.h"
   4
   5 using namespace std;
   6
   7 namespace Msp {
   8 namespace GL {
   9
  10 using namespace ProgramSyntax;
  11
  12 ProgramParser::Operator ProgramParser::operators[] =
  13 {
  14         { "[", 2, BINARY, LEFT_TO_RIGHT },
  15         { "(", 2, BINARY, LEFT_TO_RIGHT },
  16         { ".", 2, BINARY, LEFT_TO_RIGHT },
  17         { "++", 2, POSTFIX, LEFT_TO_RIGHT },
  18         { "--", 2, POSTFIX, LEFT_TO_RIGHT },
  19         { "++", 3, PREFIX, RIGHT_TO_LEFT },
  20         { "--", 3, PREFIX, RIGHT_TO_LEFT },
  21         { "+", 3, PREFIX, RIGHT_TO_LEFT },
  22         { "-", 3, PREFIX, RIGHT_TO_LEFT },
  23         { "~", 3, PREFIX, RIGHT_TO_LEFT },
  24         { "!", 3, PREFIX, RIGHT_TO_LEFT },
  25         { "*", 4, BINARY, LEFT_TO_RIGHT },
  26         { "/", 4, BINARY, LEFT_TO_RIGHT },
  27         { "%", 4, BINARY, LEFT_TO_RIGHT },
  28         { "+", 5, BINARY, LEFT_TO_RIGHT },
  29         { "-", 5, BINARY, LEFT_TO_RIGHT },
  30         { "<<", 6, BINARY, LEFT_TO_RIGHT },
  31         { ">>", 6, BINARY, LEFT_TO_RIGHT },
  32         { "<", 7, BINARY, LEFT_TO_RIGHT },
  33         { ">", 7, BINARY, LEFT_TO_RIGHT },
  34         { "<=", 7, BINARY, LEFT_TO_RIGHT },
  35         { ">=", 7, BINARY, LEFT_TO_RIGHT },
  36         { "==", 8, BINARY, LEFT_TO_RIGHT },
  37         { "!=", 8, BINARY, LEFT_TO_RIGHT },
  38         { "&", 9, BINARY, LEFT_TO_RIGHT },
  39         { "^", 10, BINARY, LEFT_TO_RIGHT },
  40         { "|", 11, BINARY, LEFT_TO_RIGHT },
  41         { "&&", 12, BINARY, LEFT_TO_RIGHT },
  42         { "^^", 13, BINARY, LEFT_TO_RIGHT },
  43         { "||", 14, BINARY, LEFT_TO_RIGHT },
  44         { "?", 15, BINARY, RIGHT_TO_LEFT },
  45         { ":", 15, BINARY, RIGHT_TO_LEFT },
  46         { "=", 16, BINARY, RIGHT_TO_LEFT },
  47         { "+=", 16, BINARY, RIGHT_TO_LEFT },
  48         { "-=", 16, BINARY, RIGHT_TO_LEFT },
  49         { "*=", 16, BINARY, RIGHT_TO_LEFT },
  50         { "/=", 16, BINARY, RIGHT_TO_LEFT },
  51         { "%=", 16, BINARY, RIGHT_TO_LEFT },
  52         { "<<=", 16, BINARY, RIGHT_TO_LEFT },
  53         { ">>=", 16, BINARY, RIGHT_TO_LEFT },
  54         { "&=", 16, BINARY, RIGHT_TO_LEFT },
  55         { "^=", 16, BINARY, RIGHT_TO_LEFT },
  56         { "|=", 16, BINARY, RIGHT_TO_LEFT },
  57         { ",", 17, BINARY, LEFT_TO_RIGHT },
  58         { { 0 }, 18, NO_OPERATOR, LEFT_TO_RIGHT }
  59 };
  60
  61 ProgramParser::ProgramParser():
  62         module(0)
  63 { }
  64
  65 ProgramParser::~ProgramParser()
  66 {
  67         delete module;
  68 }
  69
  70 Module &ProgramParser::parse(const string &s)
  71 {
  72         source = s;
  73         parse_source();
  74         return *module;
  75 }
  76
  77 Module &ProgramParser::parse(IO::Base &io)
  78 {
  79         source = string();
  80         while(!io.eof())
  81         {
  82                 char buffer[4096];
  83                 unsigned len = io.read(buffer, sizeof(buffer));
  84                 source.append(buffer, len);
  85         }
  86         parse_source();
  87         return *module;
  88 }
  89
  90 void ProgramParser::parse_source()
  91 {
  92         delete module;
  93         module = new Module;
  94         cur_stage = &module->shared;
  95         iter = source.begin();
  96         while(1)
  97         {
  98                 while(Node *statement = parse_global_declaration())
  99                         cur_stage->content.body.push_back(statement);
 100
 101                 parse_token();
 102                 string token = parse_token();
 103                 if(token.empty())
 104                         break;
 105                 else if(token=="vertex")
 106                         module->stages.push_back(VERTEX);
 107                 else if(token=="geometry")
 108                         module->stages.push_back(GEOMETRY);
 109                 else if(token=="fragment")
 110                         module->stages.push_back(FRAGMENT);
 111                 else
 112                         throw runtime_error(format("Parse error at '%s': expected stage identifier", token));
 113
 114                 if(cur_stage->type!=SHARED)
 115                         module->stages.back().previous = cur_stage;
 116                 cur_stage = &module->stages.back();
 117
 118                 for(; (iter!=source.end() && *iter!='\n'); ++iter) ;
 119         }
 120 }
 121
 122 const string &ProgramParser::peek_token(unsigned index)
 123 {
 124         while(next_tokens.size()<=index)
 125                 next_tokens.push_back(parse_token_());
 126         return next_tokens[index];
 127 }
 128
 129 string ProgramParser::parse_token()
 130 {
 131         if(!next_tokens.empty())
 132         {
 133                 string token = next_tokens.front();
 134                 next_tokens.pop_front();
 135                 return token;
 136         }
 137
 138         return parse_token_();
 139 }
 140
 141 string ProgramParser::parse_token_()
 142 {
 143         if(!skip_comment_and_whitespace())
 144                 return string();
 145
 146         if(isalpha(*iter) || *iter=='_')
 147                 return parse_identifier();
 148         else if(isdigit(*iter))
 149                 return parse_number();
 150         else
 151                 return parse_other();
 152 }
 153
 154 string ProgramParser::parse_identifier()
 155 {
 156         string ident;
 157         while(iter!=source.end())
 158         {
 159                 if(isalnum(*iter) || *iter=='_')
 160                         ident += *iter++;
 161                 else
 162                         break;
 163         }
 164
 165         return ident;
 166 }
 167
 168 string ProgramParser::parse_number()
 169 {
 170         bool accept_sign = false;
 171         string number;
 172         while(iter!=source.end())
 173         {
 174                 if(isdigit(*iter) || *iter=='.')
 175                         number += *iter++;
 176                 else if(*iter=='e' || *iter=='E')
 177                 {
 178                         number += *iter++;
 179                         accept_sign = true;
 180                 }
 181                 else if(accept_sign && (*iter=='+' || *iter=='-'))
 182                         number += *iter++;
 183                 else
 184                         break;
 185         }
 186
 187         return number;
 188 }
 189
 190 string ProgramParser::parse_other()
 191 {
 192         if(iter==source.end())
 193                 return string();
 194
 195         string token(1, *iter++);
 196         for(unsigned i=1; (i<3 && iter!=source.end()); ++i)
 197         {
 198                 bool matched = false;
 199                 for(const Operator *j=operators; (!matched && j->type); ++j)
 200                 {
 201                         matched = (j->token[i]==*iter);
 202                         for(unsigned k=0; (matched && k<i && j->token[k]); ++k)
 203                                 matched = (j->token[k]==token[k]);
 204                 }
 205
 206                 if(!matched)
 207                         break;
 208
 209                 token += *iter++;
 210         }
 211
 212         return token;
 213 }
 214
 215 bool ProgramParser::skip_comment_and_whitespace()
 216 {
 217         unsigned comment = 0;
 218         unsigned slashes = 0;
 219         while(iter!=source.end())
 220         {
 221                 if(comment==0)
 222                 {
 223                         if(*iter=='/')
 224                                 comment = 1;
 225                         else if(!isspace(*iter))
 226                                 break;
 227                 }
 228                 else if(comment==1)
 229                 {
 230                         if(*iter=='/')
 231                         {
 232                                 comment = 2;
 233                                 slashes = 2;
 234                         }
 235                         else if(*iter=='*')
 236                                 comment = 3;
 237                         else
 238                         {
 239                                 comment = 0;
 240                                 --iter;
 241                                 break;
 242                         }
 243                 }
 244                 else if(comment==2)
 245                 {
 246                         if(*iter=='\n')
 247                                 comment = 0;
 248                         else if(*iter=='/')
 249                                 ++slashes;
 250                         else if(!isspace(*iter) && slashes>=6)
 251                                 return false;
 252                 }
 253                 else if(comment==3 && *iter=='*')
 254                         comment = 4;
 255                 else if(comment==4)
 256                 {
 257                         if(*iter=='/')
 258                                 comment = 0;
 259                         else
 260                                 comment = 3;
 261                 }
 262
 263                 ++iter;
 264         }
 265
 266         return iter!=source.end();
 267 }
 268
 269 void ProgramParser::expect(const string &token)
 270 {
 271         string parsed = parse_token();
 272         if(parsed!=token)
 273                 throw runtime_error(format("Parse error at '%s': expected '%s'", parsed, token));
 274 }
 275
 276 string ProgramParser::expect_type()
 277 {
 278         string token = parse_token();
 279         if(!is_type(token))
 280                 throw runtime_error(format("Parse error at '%s': expected a type", token));
 281         return token;
 282 }
 283
 284 string ProgramParser::expect_identifier()
 285 {
 286         string token = parse_token();
 287         if(!is_identifier(token))
 288                 throw runtime_error(format("Parse error at '%s': expected an identifier", token));
 289         return token;
 290 }
 291
 292 bool ProgramParser::check(const string &token)
 293 {
 294         bool result = (peek_token()==token);
 295         if(result)
 296                 parse_token();
 297         return result;
 298 }
 299
 300 bool ProgramParser::is_interface_qualifier(const string &token)
 301 {
 302         return (token=="uniform" || token=="in" || token=="out");
 303 }
 304
 305 bool ProgramParser::is_sampling_qualifier(const string &token)
 306 {
 307         return token=="centroid";
 308 }
 309
 310 bool ProgramParser::is_qualifier(const string &token)
 311 {
 312         return (token=="const" || is_interface_qualifier(token) || is_sampling_qualifier(token));
 313 }
 314
 315 bool ProgramParser::is_builtin_type(const string &token)
 316 {
 317         static Regex re("^(void|float|int|bool|[ib]?vec[234]|mat[234](x[234])?|sampler((1D|2D)(Array)?(Shadow)?|Cube(Shadow)?|3D))$");
 318         return re.match(token);
 319 }
 320
 321 bool ProgramParser::is_type(const string &token)
 322 {
 323         return is_builtin_type(token) || declared_types.count(token);
 324 }
 325
 326 bool ProgramParser::is_identifier(const string &token)
 327 {
 328         static Regex re("^[a-zA-Z_][a-zA-Z0-9_]*$");
 329         return re.match(token);
 330 }
 331
 332 Node *ProgramParser::parse_global_declaration()
 333 {
 334         string token = peek_token();
 335         if(token=="layout")
 336                 return parse_layout();
 337         else if(token=="struct")
 338                 return parse_struct_declaration();
 339         else if(is_sampling_qualifier(token) || token=="const")
 340                 return parse_variable_declaration();
 341         else if(is_interface_qualifier(token))
 342         {
 343                 if(is_type(peek_token(1)))
 344                         return parse_variable_declaration();
 345                 else
 346                         return parse_interface_block();
 347         }
 348         else if(is_type(token))
 349         {
 350                 if(peek_token(2)=="(")
 351                         return parse_function_declaration();
 352                 else
 353                         return parse_variable_declaration();
 354         }
 355         else if(token.empty())
 356                 return 0;
 357         else
 358                 throw runtime_error(format("Syntax error at '%s': expected a global declaration", token));
 359 }
 360
 361 Node *ProgramParser::parse_statement()
 362 {
 363         string token = peek_token();
 364         if(token=="if")
 365                 return parse_conditional();
 366         else if(token=="for")
 367                 return parse_iteration();
 368         else if(token=="passthrough")
 369                 return parse_passthrough();
 370         else if(token=="return")
 371                 return parse_return();
 372         else if(is_qualifier(token) || is_type(token))
 373                 return parse_variable_declaration();
 374         else if(!token.empty())
 375         {
 376                 RefPtr<ExpressionStatement> expr = new ExpressionStatement;
 377                 expr->expression = parse_expression();
 378                 expect(";");
 379
 380                 return expr.release();
 381         }
 382         else
 383                 throw runtime_error(format("Syntax error at '%s': expected a statement", token));
 384 }
 385
 386 Layout *ProgramParser::parse_layout()
 387 {
 388         expect("layout");
 389         expect("(");
 390         RefPtr<Layout> layout = new Layout;
 391         while(1)
 392         {
 393                 string token = parse_token();
 394                 if(token==")")
 395                         throw runtime_error(format("Parse error at '%s': expected layout qualifier id", token));
 396
 397                 layout->qualifiers.push_back(Layout::Qualifier());
 398                 Layout::Qualifier &qual = layout->qualifiers.back();
 399                 qual.identifier = token;
 400
 401                 if(check("="))
 402                         qual.value = parse_token();
 403
 404                 if(peek_token()==")")
 405                         break;
 406
 407                 expect(",");
 408         }
 409         expect(")");
 410         layout->interface = parse_token();
 411         expect(";");
 412
 413         return layout.release();
 414 }
 415
 416 void ProgramParser::parse_block(Block &block, bool require_braces)
 417 {
 418         bool have_braces = (require_braces || peek_token()=="{");
 419         if(have_braces)
 420                 expect("{");
 421
 422         if(have_braces)
 423         {
 424                 while(peek_token()!="}")
 425                         block.body.push_back(parse_statement());
 426         }
 427         else
 428                 block.body.push_back(parse_statement());
 429
 430         block.use_braces = (require_braces || block.body.size()!=1);
 431
 432         if(have_braces)
 433                 expect("}");
 434 }
 435
 436 Expression *ProgramParser::parse_expression(unsigned precedence)
 437 {
 438         RefPtr<Expression> left;
 439         VariableReference *left_var = 0;
 440         while(1)
 441         {
 442                 string token = peek_token();
 443
 444                 const Operator *oper = 0;
 445                 for(Operator *i=operators; (!oper && i->type); ++i)
 446                         if(token==i->token && (!left || i->type!=PREFIX) && (left || i->type!=POSTFIX))
 447                                 oper = i;
 448
 449                 if(token==";" || token==")" || token=="]" || token=="," || (oper && precedence && oper->precedence>=precedence))
 450                 {
 451                         if(left)
 452                                 return left.release();
 453                         else
 454                                 throw runtime_error(format("Parse error at '%s': expected an expression", token));
 455                 }
 456                 else if(left)
 457                 {
 458                         if(token=="(")
 459                         {
 460                                 if(!left_var)
 461                                         throw runtime_error(format("Parse error at '%s': function name must be an identifier", token));
 462                                 left = parse_function_call(left_var);
 463                         }
 464                         else if(token==".")
 465                         {
 466                                 RefPtr<MemberAccess> memacc = new MemberAccess;
 467                                 memacc->left = left.release();
 468                                 parse_token();
 469                                 memacc->member = expect_identifier();
 470                                 left = memacc;
 471                         }
 472                         else if(oper && oper->type==POSTFIX)
 473                         {
 474                                 RefPtr<UnaryExpression> unary = new UnaryExpression;
 475                                 unary->oper = parse_token();
 476                                 unary->prefix = false;
 477                                 unary->expression = left.release();
 478                                 left = unary;
 479                         }
 480                         else if(oper && oper->type==BINARY)
 481                                 left = parse_binary(left.release(), oper);
 482                         else
 483                                 throw runtime_error(format("Parse error at '%s': expected an operator", token));
 484                         left_var = 0;
 485                 }
 486                 else
 487                 {
 488                         if(token=="(")
 489                         {
 490                                 parse_token();
 491                                 RefPtr<ParenthesizedExpression> parexpr = new ParenthesizedExpression;
 492                                 parexpr->expression = parse_expression();
 493                                 expect(")");
 494                                 left = parexpr;
 495                         }
 496                         else if(isdigit(token[0]) || token=="true" || token=="false")
 497                         {
 498                                 RefPtr<Literal> literal = new Literal;
 499                                 literal->token = parse_token();
 500                                 left = literal;
 501                         }
 502                         else if(is_identifier(token))
 503                         {
 504                                 RefPtr<VariableReference> var = new VariableReference;
 505                                 var->name = expect_identifier();
 506                                 left = var;
 507                                 left_var = var.get();
 508                         }
 509                         else if(oper && oper->type==PREFIX)
 510                         {
 511                                 RefPtr<UnaryExpression> unary = new UnaryExpression;
 512                                 unary->oper = parse_token();
 513                                 unary->prefix = true;
 514                                 unary->expression = parse_expression(oper->precedence);
 515                                 left = unary;
 516                         }
 517                         else
 518                                 throw runtime_error(format("Parse error at '%s': expected an expression", token));
 519                 }
 520         }
 521 }
 522
 523 BinaryExpression *ProgramParser::parse_binary(Expression *left, const Operator *oper)
 524 {
 525         RefPtr<BinaryExpression> binary = (oper->precedence==16 ? new Assignment : new BinaryExpression);
 526         binary->left = left;
 527         binary->oper = parse_token();
 528         if(binary->oper=="[")
 529         {
 530                 binary->right = parse_expression();
 531                 expect("]");
 532                 binary->after = "]";
 533         }
 534         else
 535                 binary->right = parse_expression(oper->precedence+(oper->assoc==RIGHT_TO_LEFT));
 536         return binary.release();
 537 }
 538
 539 FunctionCall *ProgramParser::parse_function_call(VariableReference *var)
 540 {
 541         RefPtr<FunctionCall> call = new FunctionCall;
 542         call->name = var->name;
 543         call->constructor = is_type(call->name);
 544         expect("(");
 545         while(peek_token()!=")")
 546         {
 547                 if(!call->arguments.empty())
 548                         expect(",");
 549                 call->arguments.push_back(parse_expression());
 550         }
 551         expect(")");
 552         return call.release();
 553 }
 554
 555 StructDeclaration *ProgramParser::parse_struct_declaration()
 556 {
 557         expect("struct");
 558         RefPtr<StructDeclaration> strct = new StructDeclaration;
 559
 560         strct->name = expect_identifier();
 561         parse_block(strct->members, true);
 562         expect(";");
 563
 564         declared_types.insert(strct->name);
 565         return strct.release();
 566 }
 567
 568 VariableDeclaration *ProgramParser::parse_variable_declaration()
 569 {
 570         RefPtr<VariableDeclaration> var = new VariableDeclaration;
 571
 572         string token = peek_token();
 573         if(is_sampling_qualifier(token))
 574         {
 575                 var->sampling = parse_token();
 576                 token = peek_token();
 577                 if(!is_interface_qualifier(token))
 578                         throw runtime_error(format("Parse error at '%s': expected an interface qualifier", token));
 579         }
 580
 581         if(is_interface_qualifier(token))
 582                 var->interface = parse_token();
 583         else if(token=="const")
 584         {
 585                 var->constant = true;
 586                 parse_token();
 587         }
 588
 589         var->type = expect_type();
 590         var->name = expect_identifier();
 591
 592         if(check("["))
 593         {
 594                 var->array = true;
 595                 if(!check("]"))
 596                 {
 597                         var->array_size = parse_expression();
 598                         expect("]");
 599                 }
 600         }
 601
 602         if(check("="))
 603                 var->init_expression = parse_expression();
 604
 605         expect(";");
 606         return var.release();
 607 }
 608
 609 FunctionDeclaration *ProgramParser::parse_function_declaration()
 610 {
 611         RefPtr<FunctionDeclaration> func = new FunctionDeclaration;
 612
 613         func->return_type = expect_type();
 614         func->name = expect_identifier();
 615         expect("(");
 616         while(peek_token()!=")")
 617         {
 618                 if(!func->parameters.empty())
 619                         expect(",");
 620
 621                 RefPtr<VariableDeclaration> var = new VariableDeclaration;
 622                 var->type = expect_type();
 623                 var->name = expect_identifier();
 624                 func->parameters.push_back(var.release());
 625         }
 626         expect(")");
 627
 628         string token = peek_token();
 629         if(token=="{")
 630         {
 631                 func->definition = true;
 632                 parse_block(func->body, true);
 633         }
 634         else if(token==";")
 635                 parse_token();
 636         else
 637                 throw runtime_error(format("Parse error at '%s': expected '{' or ';'", token));
 638
 639         return func.release();
 640 }
 641
 642 InterfaceBlock *ProgramParser::parse_interface_block()
 643 {
 644         RefPtr<InterfaceBlock> iface = new InterfaceBlock;
 645
 646         iface->interface = parse_token();
 647         if(!is_interface_qualifier(iface->interface))
 648                 throw runtime_error(format("Parse error at '%s': expected an interface qualifier", iface->interface));
 649
 650         iface->name = expect_identifier();
 651         parse_block(iface->members, true);
 652         if(!check(";"))
 653         {
 654                 iface->instance_name = expect_identifier();
 655                 if(check("["))
 656                 {
 657                         iface->array = true;
 658                         expect("]");
 659                 }
 660                 expect(";");
 661         }
 662
 663         return iface.release();
 664 }
 665
 666 Conditional *ProgramParser::parse_conditional()
 667 {
 668         expect("if");
 669         expect("(");
 670         RefPtr<Conditional> cond = new Conditional;
 671         cond->condition = parse_expression();
 672         expect(")");
 673
 674         parse_block(cond->body, false);
 675
 676         string token = peek_token();
 677         if(token=="else")
 678         {
 679                 parse_token();
 680                 parse_block(cond->else_body, false);
 681         }
 682
 683         return cond.release();
 684 }
 685
 686 Iteration *ProgramParser::parse_iteration()
 687 {
 688         expect("for");
 689         expect("(");
 690         RefPtr<Iteration> loop = new Iteration;
 691         string token = peek_token();
 692         if(is_type(token))
 693                 loop->init_statement = parse_statement();
 694         else
 695         {
 696                 RefPtr<ExpressionStatement> expr = new ExpressionStatement;
 697                 expr->expression = parse_expression();
 698                 expect(";");
 699                 loop->init_statement = expr.release();
 700         }
 701         loop->condition = parse_expression();
 702         expect(";");
 703         loop->loop_expression = parse_expression();
 704         expect(")");
 705
 706         parse_block(loop->body, false);
 707
 708         return loop.release();
 709 }
 710
 711 Passthrough *ProgramParser::parse_passthrough()
 712 {
 713         expect("passthrough");
 714         RefPtr<Passthrough> pass = new Passthrough;
 715         if(cur_stage->type==GEOMETRY)
 716         {
 717                 expect("[");
 718                 pass->subscript = parse_expression();
 719                 expect("]");
 720         }
 721         expect(";");
 722         return pass.release();
 723 }
 724
 725 Return *ProgramParser::parse_return()
 726 {
 727         expect("return");
 728         RefPtr<Return> ret = new Return;
 729         if(peek_token()!=";")
 730                 ret->expression = parse_expression();
 731         expect(";");
 732         return ret.release();
 733 }
 734
 735 } // namespace GL
 736 } // namespace Msp