source/programparser.cpp

   1 #include <msp/core/raii.h>
   2 #include <msp/strings/format.h>
   3 #include <msp/strings/regex.h>
   4 #include "programparser.h"
   5
   6 #undef interface
   7
   8 using namespace std;
   9
  10 namespace Msp {
  11 namespace GL {
  12
  13 using namespace ProgramSyntax;
  14
  15 ProgramParser::Operator ProgramParser::operators[] =
  16 {
  17         { "[", 2, BINARY, LEFT_TO_RIGHT },
  18         { "(", 2, BINARY, LEFT_TO_RIGHT },
  19         { ".", 2, BINARY, LEFT_TO_RIGHT },
  20         { "++", 2, POSTFIX, LEFT_TO_RIGHT },
  21         { "--", 2, POSTFIX, LEFT_TO_RIGHT },
  22         { "++", 3, PREFIX, RIGHT_TO_LEFT },
  23         { "--", 3, PREFIX, RIGHT_TO_LEFT },
  24         { "+", 3, PREFIX, RIGHT_TO_LEFT },
  25         { "-", 3, PREFIX, RIGHT_TO_LEFT },
  26         { "~", 3, PREFIX, RIGHT_TO_LEFT },
  27         { "!", 3, PREFIX, RIGHT_TO_LEFT },
  28         { "*", 4, BINARY, LEFT_TO_RIGHT },
  29         { "/", 4, BINARY, LEFT_TO_RIGHT },
  30         { "%", 4, BINARY, LEFT_TO_RIGHT },
  31         { "+", 5, BINARY, LEFT_TO_RIGHT },
  32         { "-", 5, BINARY, LEFT_TO_RIGHT },
  33         { "<<", 6, BINARY, LEFT_TO_RIGHT },
  34         { ">>", 6, BINARY, LEFT_TO_RIGHT },
  35         { "<", 7, BINARY, LEFT_TO_RIGHT },
  36         { ">", 7, BINARY, LEFT_TO_RIGHT },
  37         { "<=", 7, BINARY, LEFT_TO_RIGHT },
  38         { ">=", 7, BINARY, LEFT_TO_RIGHT },
  39         { "==", 8, BINARY, LEFT_TO_RIGHT },
  40         { "!=", 8, BINARY, LEFT_TO_RIGHT },
  41         { "&", 9, BINARY, LEFT_TO_RIGHT },
  42         { "^", 10, BINARY, LEFT_TO_RIGHT },
  43         { "|", 11, BINARY, LEFT_TO_RIGHT },
  44         { "&&", 12, BINARY, LEFT_TO_RIGHT },
  45         { "^^", 13, BINARY, LEFT_TO_RIGHT },
  46         { "||", 14, BINARY, LEFT_TO_RIGHT },
  47         { "?", 15, BINARY, RIGHT_TO_LEFT },
  48         { ":", 15, 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         { "&=", 16, BINARY, RIGHT_TO_LEFT },
  58         { "^=", 16, BINARY, RIGHT_TO_LEFT },
  59         { "|=", 16, BINARY, RIGHT_TO_LEFT },
  60         { ",", 17, BINARY, LEFT_TO_RIGHT },
  61         { { 0 }, 18, NO_OPERATOR, LEFT_TO_RIGHT }
  62 };
  63
  64 ProgramParser::ProgramParser():
  65         module(0)
  66 { }
  67
  68 ProgramParser::~ProgramParser()
  69 {
  70         delete module;
  71 }
  72
  73 Module &ProgramParser::parse(const string &s, const string &n, unsigned i)
  74 {
  75         source = s;
  76         source_name = n;
  77         source_index = i;
  78         parse_source();
  79         return *module;
  80 }
  81
  82 Module &ProgramParser::parse(IO::Base &io, const string &n, unsigned i)
  83 {
  84         source = string();
  85         source_name = n;
  86         source_index = i;
  87         while(!io.eof())
  88         {
  89                 char buffer[4096];
  90                 unsigned len = io.read(buffer, sizeof(buffer));
  91                 source.append(buffer, len);
  92         }
  93         parse_source();
  94         return *module;
  95 }
  96
  97 void ProgramParser::parse_source()
  98 {
  99         while(1)
 100         {
 101                 string::size_type slashes = source.find("//////");
 102                 if(slashes==string::npos)
 103                         break;
 104
 105                 string::size_type newline = source.find('\n', slashes);
 106                 string pragma = format("#pragma MSP stage(%s)", source.substr(slashes+6, newline-slashes-6));
 107                 source.replace(slashes, newline-slashes, pragma);
 108         }
 109
 110         delete module;
 111         module = new Module;
 112         cur_stage = &module->shared;
 113         iter = source.begin();
 114         source_end = source.end();
 115         current_line = 1;
 116         allow_preprocess = true;
 117         while(RefPtr<Statement> statement = parse_global_declaration())
 118                 cur_stage->content.body.push_back(statement);
 119 }
 120
 121 string ProgramParser::format_error(const std::string &message)
 122 {
 123         string location = format("%s:%d: ", source_name, current_line);
 124         return location+message;
 125 }
 126
 127 string ProgramParser::format_syntax_error(const std::string &expected)
 128 {
 129         return format_error(format("Syntax error at '%s': expected %s", last_token, expected));
 130 }
 131
 132 const string &ProgramParser::peek_token(unsigned index)
 133 {
 134         while(next_tokens.size()<=index)
 135                 next_tokens.push_back(parse_token_());
 136         return (last_token = next_tokens[index]);
 137 }
 138
 139 const string &ProgramParser::parse_token()
 140 {
 141         if(!next_tokens.empty())
 142         {
 143                 last_token = next_tokens.front();
 144                 next_tokens.pop_front();
 145                 return last_token;
 146         }
 147
 148         return (last_token = parse_token_());
 149 }
 150
 151 string ProgramParser::parse_token_()
 152 {
 153         while(1)
 154         {
 155                 skip_comment_and_whitespace();
 156                 if(iter==source_end)
 157                         return string();
 158                 else if(allow_preprocess && *iter=='#')
 159                 {
 160                         allow_preprocess = false;
 161                         SetForScope<deque<string> > clear_tokens(next_tokens, deque<string>());
 162                         preprocess();
 163                 }
 164                 else if(isalpha(*iter) || *iter=='_')
 165                         return parse_identifier();
 166                 else if(isdigit(*iter))
 167                         return parse_number();
 168                 else
 169                         return parse_other();
 170         }
 171 }
 172
 173 string ProgramParser::parse_identifier()
 174 {
 175         string ident;
 176         while(iter!=source_end)
 177         {
 178                 if(isalnum(*iter) || *iter=='_')
 179                         ident += *iter++;
 180                 else
 181                         break;
 182         }
 183
 184         return ident;
 185 }
 186
 187 string ProgramParser::parse_number()
 188 {
 189         bool accept_sign = false;
 190         string number;
 191         while(iter!=source_end)
 192         {
 193                 if(isdigit(*iter) || *iter=='.')
 194                         number += *iter++;
 195                 else if(*iter=='e' || *iter=='E')
 196                 {
 197                         number += *iter++;
 198                         accept_sign = true;
 199                 }
 200                 else if(accept_sign && (*iter=='+' || *iter=='-'))
 201                         number += *iter++;
 202                 else
 203                         break;
 204         }
 205
 206         return number;
 207 }
 208
 209 string ProgramParser::parse_other()
 210 {
 211         if(iter==source_end)
 212                 return string();
 213
 214         string token(1, *iter++);
 215         for(unsigned i=1; (i<3 && iter!=source_end); ++i)
 216         {
 217                 bool matched = false;
 218                 for(const Operator *j=operators; (!matched && j->type); ++j)
 219                 {
 220                         matched = (j->token[i]==*iter);
 221                         for(unsigned k=0; (matched && k<i && j->token[k]); ++k)
 222                                 matched = (j->token[k]==token[k]);
 223                 }
 224
 225                 if(!matched)
 226                         break;
 227
 228                 token += *iter++;
 229         }
 230
 231         return token;
 232 }
 233
 234 void ProgramParser::skip_comment_and_whitespace()
 235 {
 236         unsigned comment = 0;
 237         while(iter!=source_end)
 238         {
 239                 if(comment==0)
 240                 {
 241                         if(*iter=='/')
 242                                 comment = 1;
 243                         else if(!isspace(*iter))
 244                                 break;
 245                 }
 246                 else if(comment==1)
 247                 {
 248                         if(*iter=='/')
 249                                 comment = 2;
 250                         else if(*iter=='*')
 251                                 comment = 3;
 252                         else
 253                         {
 254                                 comment = 0;
 255                                 --iter;
 256                                 break;
 257                         }
 258                 }
 259                 else if(comment==2)
 260                 {
 261                         if(*iter=='\n')
 262                                 comment = 0;
 263                 }
 264                 else if(comment==3 && *iter=='*')
 265                         comment = 4;
 266                 else if(comment==4)
 267                 {
 268                         if(*iter=='/')
 269                                 comment = 0;
 270                         else if(*iter!='*')
 271                                 comment = 3;
 272                 }
 273
 274                 if(*iter=='\n')
 275                 {
 276                         ++current_line;
 277                         allow_preprocess = (comment<3);
 278                 }
 279
 280                 ++iter;
 281         }
 282 }
 283
 284 void ProgramParser::expect(const string &token)
 285 {
 286         string parsed = parse_token();
 287         if(parsed!=token)
 288                 throw runtime_error(format_syntax_error(format("'%s'", token)));
 289 }
 290
 291 string ProgramParser::expect_type()
 292 {
 293         string token = parse_token();
 294         if(!is_type(token))
 295                 throw runtime_error(format_syntax_error("a type"));
 296         return token;
 297 }
 298
 299 string ProgramParser::expect_identifier()
 300 {
 301         string token = parse_token();
 302         if(!is_identifier(token))
 303                 throw runtime_error(format_syntax_error("an identifier"));
 304         return token;
 305 }
 306
 307 bool ProgramParser::check(const string &token)
 308 {
 309         bool result = (peek_token()==token);
 310         if(result)
 311                 parse_token();
 312         return result;
 313 }
 314
 315 bool ProgramParser::is_interface_qualifier(const string &token)
 316 {
 317         return (token=="uniform" || token=="in" || token=="out");
 318 }
 319
 320 bool ProgramParser::is_sampling_qualifier(const string &token)
 321 {
 322         return (token=="centroid" || token=="sample");
 323 }
 324
 325 bool ProgramParser::is_interpolation_qualifier(const string &token)
 326 {
 327         return (token=="smooth" || token=="flat" || token=="noperspective");
 328 }
 329
 330 bool ProgramParser::is_precision_qualifier(const string &token)
 331 {
 332         return (token=="highp" || token=="mediump" || token=="lowp");
 333 }
 334
 335 bool ProgramParser::is_qualifier(const string &token)
 336 {
 337         return (token=="const" ||
 338                 is_interface_qualifier(token) ||
 339                 is_sampling_qualifier(token) ||
 340                 is_interpolation_qualifier(token) ||
 341                 is_precision_qualifier(token));
 342 }
 343
 344 bool ProgramParser::is_builtin_type(const string &token)
 345 {
 346         static Regex re("^(void|float|int|bool|[ib]?vec[234]|mat[234](x[234])?|sampler((1D|2D)(Array)?(Shadow)?|Cube(Shadow)?|3D))$");
 347         return re.match(token);
 348 }
 349
 350 bool ProgramParser::is_type(const string &token)
 351 {
 352         return is_builtin_type(token) || declared_types.count(token);
 353 }
 354
 355 bool ProgramParser::is_identifier(const string &token)
 356 {
 357         static Regex re("^[a-zA-Z_][a-zA-Z0-9_]*$");
 358         return re.match(token);
 359 }
 360
 361 void ProgramParser::preprocess()
 362 {
 363         expect("#");
 364
 365         string::const_iterator line_end = iter;
 366         for(; (line_end!=source_end && *line_end!='\n'); ++line_end) ;
 367         SetForScope<string::const_iterator> stop_at_line_end(source_end, line_end);
 368
 369         string token = peek_token();
 370         if(token=="pragma")
 371                 preprocess_pragma();
 372         else if(token=="define" || token=="undef" || token=="if" || token=="ifdef" || token=="ifndef" || token=="else" ||
 373                 token=="elif" || token=="endif" || token=="error" || token=="extension" || token=="version" || token=="line")
 374                 throw runtime_error(format_error(format("Unsupported preprocessor directive '%s'", token)));
 375         else if(!token.empty())
 376                 throw runtime_error(format_syntax_error("a preprocessor directive"));
 377
 378         iter = line_end;
 379 }
 380
 381 void ProgramParser::preprocess_pragma()
 382 {
 383         expect("pragma");
 384         string token = parse_token();
 385         if(token=="MSP")
 386                 preprocess_pragma_msp();
 387 }
 388
 389 void ProgramParser::preprocess_pragma_msp()
 390 {
 391         string token = peek_token();
 392         if(token=="stage")
 393                 preprocess_stage();
 394         else
 395                 throw runtime_error(format_error(format("Unrecognized MSP pragma '%s'", token)));
 396
 397         token = parse_token();
 398         if(!token.empty())
 399                 throw runtime_error(format_syntax_error("end of line"));
 400 }
 401
 402 void ProgramParser::preprocess_stage()
 403 {
 404         if(!allow_stage_change)
 405                 throw runtime_error(format_error("Changing stage not allowed here"));
 406
 407         expect("stage");
 408         expect("(");
 409         string token = expect_identifier();
 410         StageType stage = SHARED;
 411         if(token=="vertex")
 412                 stage = VERTEX;
 413         else if(token=="geometry")
 414                 stage = GEOMETRY;
 415         else if(token=="fragment")
 416                 stage = FRAGMENT;
 417         else
 418                 throw runtime_error(format_syntax_error("stage identifier"));
 419         expect(")");
 420
 421         if(stage<=cur_stage->type)
 422                 throw runtime_error(format_error(format("Stage '%s' not allowed here", token)));
 423
 424         module->stages.push_back(stage);
 425
 426         if(cur_stage->type!=SHARED)
 427                 module->stages.back().previous = cur_stage;
 428         cur_stage = &module->stages.back();
 429 }
 430
 431 RefPtr<Statement> ProgramParser::parse_global_declaration()
 432 {
 433         allow_stage_change = true;
 434         string token = peek_token();
 435         allow_stage_change = false;
 436
 437         if(token=="import")
 438                 return parse_import();
 439         else if(token=="precision")
 440                 return parse_precision();
 441         else if(token=="layout")
 442         {
 443                 RefPtr<Layout> layout = parse_layout();
 444                 token = peek_token();
 445                 if(is_interface_qualifier(token) && peek_token(1)==";")
 446                 {
 447                         RefPtr<InterfaceLayout> iface_lo = new InterfaceLayout;
 448                         iface_lo->source = source_index;
 449                         iface_lo->line = current_line;
 450                         iface_lo->layout.qualifiers = layout->qualifiers;
 451                         iface_lo->interface = parse_token();
 452                         expect(";");
 453                         return iface_lo;
 454                 }
 455                 else
 456                 {
 457                         RefPtr<VariableDeclaration> var = parse_variable_declaration();
 458                         var->layout = layout;
 459                         return var;
 460                 }
 461         }
 462         else if(token=="struct")
 463                 return parse_struct_declaration();
 464         else if(is_interface_qualifier(token))
 465         {
 466                 string next = peek_token(1);
 467                 if(is_type(next) || is_qualifier(next))
 468                         return parse_variable_declaration();
 469                 else
 470                         return parse_interface_block();
 471         }
 472         else if(is_qualifier(token))
 473                 return parse_variable_declaration();
 474         else if(is_type(token))
 475         {
 476                 if(peek_token(2)=="(")
 477                         return parse_function_declaration();
 478                 else
 479                         return parse_variable_declaration();
 480         }
 481         else if(token.empty())
 482                 return 0;
 483         else
 484                 throw runtime_error(format_syntax_error("a global declaration"));
 485 }
 486
 487 RefPtr<Statement> ProgramParser::parse_statement()
 488 {
 489         string token = peek_token();
 490         if(token=="if")
 491                 return parse_conditional();
 492         else if(token=="for")
 493                 return parse_for();
 494         else if(token=="while")
 495                 return parse_while();
 496         else if(token=="passthrough")
 497                 return parse_passthrough();
 498         else if(token=="return")
 499                 return parse_return();
 500         else if(token=="break" || token=="continue" || token=="discard")
 501         {
 502                 RefPtr<Jump> jump = new Jump;
 503                 jump->source = source_index;
 504                 jump->line = current_line;
 505                 jump->keyword = parse_token();
 506                 expect(";");
 507
 508                 return jump;
 509         }
 510         else if(is_qualifier(token) || is_type(token))
 511                 return parse_variable_declaration();
 512         else if(!token.empty())
 513         {
 514                 RefPtr<ExpressionStatement> expr = new ExpressionStatement;
 515                 expr->source = source_index;
 516                 expr->line = current_line;
 517                 expr->expression = parse_expression();
 518                 expect(";");
 519
 520                 return expr;
 521         }
 522         else
 523                 throw runtime_error(format_syntax_error("a statement"));
 524 }
 525
 526 RefPtr<Import> ProgramParser::parse_import()
 527 {
 528         if(cur_stage->type!=SHARED)
 529                 throw runtime_error(format_error("Imports are only allowed in the shared section"));
 530
 531         expect("import");
 532         RefPtr<Import> import = new Import;
 533         import->source = source_index;
 534         import->line = current_line;
 535         import->module = expect_identifier();
 536         expect(";");
 537         return import;
 538 }
 539
 540 RefPtr<Precision> ProgramParser::parse_precision()
 541 {
 542         expect("precision");
 543         RefPtr<Precision> precision = new Precision;
 544         precision->source = source_index;
 545         precision->line = current_line;
 546
 547         precision->precision = parse_token();
 548         if(!is_precision_qualifier(precision->precision))
 549                 throw runtime_error(format_syntax_error("a precision qualifier"));
 550
 551         precision->type = parse_token();
 552         // Not entirely accurate; only float, int and sampler types are allowed
 553         if(!is_builtin_type(precision->type))
 554                 throw runtime_error(format_syntax_error("a builtin type"));
 555
 556         expect(";");
 557
 558         return precision;
 559 }
 560
 561 RefPtr<Layout> ProgramParser::parse_layout()
 562 {
 563         expect("layout");
 564         expect("(");
 565         RefPtr<Layout> layout = new Layout;
 566         while(1)
 567         {
 568                 string token = parse_token();
 569                 if(token==")")
 570                         throw runtime_error(format_syntax_error("a layout qualifier name"));
 571
 572                 layout->qualifiers.push_back(Layout::Qualifier());
 573                 Layout::Qualifier &qual = layout->qualifiers.back();
 574                 qual.identifier = token;
 575
 576                 if(check("="))
 577                         qual.value = parse_token();
 578
 579                 if(peek_token()==")")
 580                         break;
 581
 582                 expect(",");
 583         }
 584         expect(")");
 585
 586         return layout;
 587 }
 588
 589 void ProgramParser::parse_block(Block &block, bool require_braces)
 590 {
 591         bool have_braces = (require_braces || peek_token()=="{");
 592         if(have_braces)
 593                 expect("{");
 594
 595         if(have_braces)
 596         {
 597                 while(peek_token()!="}")
 598                         block.body.push_back(parse_statement());
 599         }
 600         else
 601                 block.body.push_back(parse_statement());
 602
 603         block.use_braces = (require_braces || block.body.size()!=1);
 604
 605         if(have_braces)
 606                 expect("}");
 607 }
 608
 609 RefPtr<Expression> ProgramParser::parse_expression(unsigned precedence)
 610 {
 611         RefPtr<Expression> left;
 612         VariableReference *left_var = 0;
 613         while(1)
 614         {
 615                 string token = peek_token();
 616
 617                 const Operator *oper = 0;
 618                 for(Operator *i=operators; (!oper && i->type); ++i)
 619                         if(token==i->token && (!left || i->type!=PREFIX) && (left || i->type!=POSTFIX))
 620                                 oper = i;
 621
 622                 if(token==";" || token==")" || token=="]" || token=="," || (oper && precedence && oper->precedence>=precedence))
 623                 {
 624                         if(left)
 625                                 return left;
 626                         else
 627                                 throw runtime_error(format_syntax_error("an expression"));
 628                 }
 629                 else if(left)
 630                 {
 631                         if(token=="(")
 632                         {
 633                                 if(!left_var)
 634                                         throw runtime_error(format_error("Syntax error before '(': function name must be an identifier"));
 635                                 left = parse_function_call(*left_var);
 636                         }
 637                         else if(token==".")
 638                         {
 639                                 RefPtr<MemberAccess> memacc = new MemberAccess;
 640                                 memacc->left = left;
 641                                 parse_token();
 642                                 memacc->member = expect_identifier();
 643                                 left = memacc;
 644                         }
 645                         else if(oper && oper->type==POSTFIX)
 646                         {
 647                                 RefPtr<UnaryExpression> unary = new UnaryExpression;
 648                                 unary->oper = parse_token();
 649                                 unary->prefix = false;
 650                                 unary->expression = left;
 651                                 left = unary;
 652                         }
 653                         else if(oper && oper->type==BINARY)
 654                                 left = parse_binary(left, oper);
 655                         else
 656                                 throw runtime_error(format_syntax_error("an operator"));
 657                         left_var = 0;
 658                 }
 659                 else
 660                 {
 661                         if(token=="(")
 662                         {
 663                                 parse_token();
 664                                 RefPtr<ParenthesizedExpression> parexpr = new ParenthesizedExpression;
 665                                 parexpr->expression = parse_expression();
 666                                 expect(")");
 667                                 left = parexpr;
 668                         }
 669                         else if(isdigit(token[0]) || token=="true" || token=="false")
 670                         {
 671                                 RefPtr<Literal> literal = new Literal;
 672                                 literal->token = parse_token();
 673                                 left = literal;
 674                         }
 675                         else if(is_identifier(token))
 676                         {
 677                                 RefPtr<VariableReference> var = new VariableReference;
 678                                 var->name = expect_identifier();
 679                                 left = var;
 680                                 left_var = var.get();
 681                         }
 682                         else if(oper && oper->type==PREFIX)
 683                         {
 684                                 RefPtr<UnaryExpression> unary = new UnaryExpression;
 685                                 unary->oper = parse_token();
 686                                 unary->prefix = true;
 687                                 unary->expression = parse_expression(oper->precedence);
 688                                 left = unary;
 689                         }
 690                         else
 691                                 throw runtime_error(format_syntax_error("an expression"));
 692                 }
 693         }
 694 }
 695
 696 RefPtr<BinaryExpression> ProgramParser::parse_binary(const RefPtr<Expression> &left, const Operator *oper)
 697 {
 698         RefPtr<BinaryExpression> binary = (oper->precedence==16 ? new Assignment : new BinaryExpression);
 699         binary->left = left;
 700         binary->oper = parse_token();
 701         if(binary->oper=="[")
 702         {
 703                 binary->right = parse_expression();
 704                 expect("]");
 705                 binary->after = "]";
 706         }
 707         else
 708                 binary->right = parse_expression(oper->precedence+(oper->assoc==RIGHT_TO_LEFT));
 709         return binary;
 710 }
 711
 712 RefPtr<FunctionCall> ProgramParser::parse_function_call(const VariableReference &var)
 713 {
 714         RefPtr<FunctionCall> call = new FunctionCall;
 715         call->name = var.name;
 716         call->constructor = is_type(call->name);
 717         expect("(");
 718         while(peek_token()!=")")
 719         {
 720                 if(!call->arguments.empty())
 721                         expect(",");
 722                 call->arguments.push_back(parse_expression());
 723         }
 724         expect(")");
 725         return call;
 726 }
 727
 728 RefPtr<StructDeclaration> ProgramParser::parse_struct_declaration()
 729 {
 730         expect("struct");
 731         RefPtr<StructDeclaration> strct = new StructDeclaration;
 732         strct->source = source_index;
 733         strct->line = current_line;
 734
 735         strct->name = expect_identifier();
 736         parse_block(strct->members, true);
 737         expect(";");
 738
 739         declared_types.insert(strct->name);
 740         return strct;
 741 }
 742
 743 RefPtr<VariableDeclaration> ProgramParser::parse_variable_declaration()
 744 {
 745         RefPtr<VariableDeclaration> var = new VariableDeclaration;
 746         var->source = source_index;
 747         var->line = current_line;
 748
 749         string token = peek_token();
 750         while(is_qualifier(token))
 751         {
 752                 parse_token();
 753                 if(is_interface_qualifier(token))
 754                         var->interface = token;
 755                 else if(is_sampling_qualifier(token))
 756                         var->sampling = token;
 757                 else if(is_interpolation_qualifier(token))
 758                         var->interpolation = token;
 759                 else if(is_precision_qualifier(token))
 760                         var->precision = token;
 761                 else if(token=="const")
 762                         var->constant = true;
 763                 token = peek_token();
 764         }
 765
 766         var->type = expect_type();
 767         var->name = expect_identifier();
 768
 769         if(check("["))
 770         {
 771                 var->array = true;
 772                 if(!check("]"))
 773                 {
 774                         var->array_size = parse_expression();
 775                         expect("]");
 776                 }
 777         }
 778
 779         if(check("="))
 780                 var->init_expression = parse_expression();
 781
 782         expect(";");
 783         return var;
 784 }
 785
 786 RefPtr<FunctionDeclaration> ProgramParser::parse_function_declaration()
 787 {
 788         RefPtr<FunctionDeclaration> func = new FunctionDeclaration;
 789         func->source = source_index;
 790         func->line = current_line;
 791
 792         func->return_type = expect_type();
 793         func->name = expect_identifier();
 794         expect("(");
 795         while(peek_token()!=")")
 796         {
 797                 if(!func->parameters.empty())
 798                         expect(",");
 799
 800                 RefPtr<VariableDeclaration> var = new VariableDeclaration;
 801                 string token = peek_token();
 802                 if(token=="in" || token=="out" || token=="inout")
 803                         var->interface = parse_token();
 804                 var->type = expect_type();
 805                 var->name = expect_identifier();
 806                 func->parameters.push_back(var);
 807         }
 808         expect(")");
 809
 810         string token = peek_token();
 811         if(token=="{")
 812         {
 813                 func->definition = func.get();
 814                 parse_block(func->body, true);
 815         }
 816         else if(token==";")
 817                 parse_token();
 818         else
 819                 throw runtime_error(format_syntax_error("'{' or ';'"));
 820
 821         return func;
 822 }
 823
 824 RefPtr<InterfaceBlock> ProgramParser::parse_interface_block()
 825 {
 826         RefPtr<InterfaceBlock> iface = new InterfaceBlock;
 827         iface->source = source_index;
 828         iface->line = current_line;
 829
 830         iface->interface = parse_token();
 831         if(!is_interface_qualifier(iface->interface))
 832                 throw runtime_error(format_syntax_error("an interface qualifier"));
 833
 834         iface->name = expect_identifier();
 835         parse_block(iface->members, true);
 836         if(!check(";"))
 837         {
 838                 iface->instance_name = expect_identifier();
 839                 if(check("["))
 840                 {
 841                         iface->array = true;
 842                         expect("]");
 843                 }
 844                 expect(";");
 845         }
 846
 847         return iface;
 848 }
 849
 850 RefPtr<Conditional> ProgramParser::parse_conditional()
 851 {
 852         expect("if");
 853         RefPtr<Conditional> cond = new Conditional;
 854         cond->source = source_index;
 855         cond->line = current_line;
 856         expect("(");
 857         cond->condition = parse_expression();
 858         expect(")");
 859
 860         parse_block(cond->body, false);
 861
 862         string token = peek_token();
 863         if(token=="else")
 864         {
 865                 parse_token();
 866                 parse_block(cond->else_body, false);
 867         }
 868
 869         return cond;
 870 }
 871
 872 RefPtr<Iteration> ProgramParser::parse_for()
 873 {
 874         expect("for");
 875         RefPtr<Iteration> loop = new Iteration;
 876         loop->source = source_index;
 877         loop->line = current_line;
 878         expect("(");
 879         string token = peek_token();
 880         if(is_type(token))
 881                 loop->init_statement = parse_statement();
 882         else
 883         {
 884                 if(token!=";")
 885                 {
 886                         RefPtr<ExpressionStatement> expr = new ExpressionStatement;
 887                         expr->expression = parse_expression();
 888                         loop->init_statement = expr;
 889                 }
 890                 expect(";");
 891         }
 892         if(peek_token()!=";")
 893                 loop->condition = parse_expression();
 894         expect(";");
 895         if(peek_token()!=")")
 896                 loop->loop_expression = parse_expression();
 897         expect(")");
 898
 899         parse_block(loop->body, false);
 900
 901         return loop;
 902 }
 903
 904 RefPtr<Iteration> ProgramParser::parse_while()
 905 {
 906         expect("while");
 907         RefPtr<Iteration> loop = new Iteration;
 908         loop->source = source_index;
 909         loop->line = current_line;
 910         expect("(");
 911         loop->condition = parse_expression();
 912         expect(")");
 913
 914         parse_block(loop->body, false);
 915
 916         return loop;
 917 }
 918
 919 RefPtr<Passthrough> ProgramParser::parse_passthrough()
 920 {
 921         expect("passthrough");
 922         RefPtr<Passthrough> pass = new Passthrough;
 923         pass->source = source_index;
 924         pass->line = current_line;
 925         if(cur_stage->type==GEOMETRY)
 926         {
 927                 expect("[");
 928                 pass->subscript = parse_expression();
 929                 expect("]");
 930         }
 931         expect(";");
 932         return pass;
 933 }
 934
 935 RefPtr<Return> ProgramParser::parse_return()
 936 {
 937         expect("return");
 938         RefPtr<Return> ret = new Return;
 939         ret->source = source_index;
 940         ret->line = current_line;
 941         if(peek_token()!=";")
 942                 ret->expression = parse_expression();
 943         expect(";");
 944         return ret;
 945 }
 946
 947 } // namespace GL
 948 } // namespace Msp