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Rename InterfaceBlock::name to block_name for clarity
[libs/gl.git] / source / glsl / parser.cpp
1 #include <msp/core/raii.h>
2 #include <msp/strings/format.h>
3 #include <msp/strings/regex.h>
4 #include <msp/strings/utils.h>
5 #include "builtin.h"
6 #include "glsl_error.h"
7 #include "parser.h"
8
9 #undef interface
10
11 using namespace std;
12
13 namespace Msp {
14 namespace GL {
15 namespace SL {
16
17 Parser::Parser():
18         preprocessor(tokenizer),
19         module(0)
20 {
21         tokenizer.signal_preprocess.connect(sigc::mem_fun(&preprocessor, &Preprocessor::preprocess));
22         preprocessor.signal_version.connect(sigc::mem_fun(this, &Parser::set_required_version));
23         preprocessor.signal_source.connect(sigc::mem_fun(this, &Parser::source_reference));
24         preprocessor.signal_stage_change.connect(sigc::mem_fun(this, &Parser::stage_change));
25         preprocessor.signal_line.connect(sigc::mem_fun(this, &Parser::line_change));
26 }
27
28 Parser::~Parser()
29 {
30         delete module;
31 }
32
33 Module &Parser::parse(const string &s, const string &n, int i)
34 {
35         source = s;
36         parse_source(n, i);
37         return *module;
38 }
39
40 Module &Parser::parse(IO::Base &io, const string &n, int i)
41 {
42         source = string();
43         while(!io.eof())
44         {
45                 char buffer[4096];
46                 unsigned len = io.read(buffer, sizeof(buffer));
47                 source.append(buffer, len);
48         }
49         parse_source(n, i);
50         return *module;
51 }
52
53 void Parser::parse_source(const string &name, int index)
54 {
55         delete module;
56         module = new Module;
57
58         cur_stage = &module->shared;
59         base_index = index;
60         source_index = index;
61         if(index>=0)
62                 source_reference(1, name);
63
64         // TODO Need to somehow get type names from imports
65         if(const Stage *builtin = get_builtins(Stage::SHARED))
66         {
67                 for(map<string, TypeDeclaration *>::const_iterator i=builtin->types.begin(); i!=builtin->types.end(); ++i)
68                         declared_types.insert(i->first);
69         }
70         else
71         {
72                 declared_types.insert("void");
73                 declared_types.insert("bool");
74                 declared_types.insert("int");
75                 declared_types.insert("float");
76         }
77
78         tokenizer.begin(source, name);
79         allow_stage_change = true;
80         while(!tokenizer.peek_token().empty())
81                 if(RefPtr<Statement> statement = parse_with_recovery(&Parser::parse_global_declaration))
82                         cur_stage->content.body.push_back(statement);
83
84         if(!errors.empty())
85                 throw invalid_shader_source(join(errors.begin(), errors.end(), "\n"));
86 }
87
88 void Parser::set_required_version(const Version &ver)
89 {
90         cur_stage->required_features.glsl_version = ver;
91 }
92
93 void Parser::source_reference(unsigned index, const string &name)
94 {
95         if(index<1 || base_index<0)
96                 throw invalid_shader_source(tokenizer.get_location(), "Invalid source reference");
97
98         module->source_map.set_name(base_index+index-1, name);
99 }
100
101 void Parser::stage_change(Stage::Type stage)
102 {
103         if(!allow_stage_change)
104                 throw invalid_shader_source(tokenizer.get_location(), "Changing stage not allowed here");
105         else if(stage<=cur_stage->type)
106                 throw invalid_shader_source(tokenizer.get_location(), "Stage '%s' not allowed here", Stage::get_stage_name(stage));
107
108         module->stages.push_back(stage);
109
110         if(cur_stage->type!=Stage::SHARED)
111                 module->stages.back().previous = cur_stage;
112         cur_stage = &module->stages.back();
113 }
114
115 void Parser::line_change(int index, unsigned line)
116 {
117         if(index>0)
118                 source_index = base_index+index-1;
119         else if(index==0)
120                 source_index = 0;
121         else
122                 index = source_index;
123
124         string name = module->source_map.get_name(index);
125         if(name.empty())
126                 name = format("<%d>", index);
127         tokenizer.set_location(Location(name, line));
128 }
129
130 string Parser::expect_type()
131 {
132         string token = tokenizer.parse_token();
133         if(!is_type(token))
134                 throw parse_error(tokenizer.get_location(), token, "a type");
135         return token;
136 }
137
138 string Parser::expect_identifier()
139 {
140         string token = tokenizer.parse_token();
141         if(!is_identifier(token))
142                 throw parse_error(tokenizer.get_location(), token, "an identifier");
143         return token;
144 }
145
146 int Parser::expect_integer()
147 {
148         string token = tokenizer.parse_token();
149         if(!isnumrc(token))
150                 throw parse_error(tokenizer.get_location(), token, "an integer literal");
151         return lexical_cast<int>(token);
152 }
153
154 bool Parser::check(const string &token)
155 {
156         bool result = (tokenizer.peek_token()==token);
157         if(result)
158                 tokenizer.parse_token();
159         return result;
160 }
161
162 bool Parser::is_interface_qualifier(const string &token)
163 {
164         return (token=="uniform" || token=="in" || token=="out");
165 }
166
167 bool Parser::is_sampling_qualifier(const string &token)
168 {
169         return (token=="centroid" || token=="sample");
170 }
171
172 bool Parser::is_interpolation_qualifier(const string &token)
173 {
174         return (token=="smooth" || token=="flat" || token=="noperspective");
175 }
176
177 bool Parser::is_precision_qualifier(const string &token)
178 {
179         return (token=="highp" || token=="mediump" || token=="lowp");
180 }
181
182 bool Parser::is_qualifier(const string &token)
183 {
184         return (token=="const" ||
185                 is_interface_qualifier(token) ||
186                 is_sampling_qualifier(token) ||
187                 is_interpolation_qualifier(token) ||
188                 is_precision_qualifier(token));
189 }
190
191 bool Parser::is_type(const string &token)
192 {
193         return declared_types.count(token);
194 }
195
196 bool Parser::is_identifier(const string &token)
197 {
198         static Regex re("^[a-zA-Z_][a-zA-Z0-9_]*$");
199         return re.match(token);
200 }
201
202 template<typename T>
203 RefPtr<T> Parser::create_node()
204 {
205         RefPtr<T> node = new T;
206         node->source = source_index;
207         node->line = tokenizer.get_location().line;
208         return node;
209 }
210
211 template<typename T>
212 RefPtr<T> Parser::parse_with_recovery(RefPtr<T> (Parser::*parse_func)())
213 {
214         tokenizer.clear_progress_mark();
215         try
216         {
217                 return (this->*parse_func)();
218         }
219         catch(const invalid_shader_source &exc)
220         {
221                 errors.push_back(exc.what());
222         }
223
224         if(tokenizer.get_last_token()!=";" || !tokenizer.get_progress_mark())
225         {
226                 unsigned scope_level = 0;
227                 while(1)
228                 {
229                         if(tokenizer.peek_token()=="}" && scope_level==0)
230                         {
231                                 if(!tokenizer.get_progress_mark())
232                                         tokenizer.parse_token();
233                                 break;
234                         }
235
236                         string token = tokenizer.parse_token();
237                         if(token=="}")
238                         {
239                                 --scope_level;
240                                 if(scope_level==0)
241                                         break;
242                         }
243                         else if(token=="{")
244                                 ++scope_level;
245                         else if(token==";" && scope_level==0)
246                                 break;
247                         else if(token.empty())
248                                 break;
249                 }
250         }
251
252         return RefPtr<T>();
253 }
254
255 RefPtr<Statement> Parser::parse_global_declaration()
256 {
257         string token = tokenizer.peek_token();
258         SetFlag disallow(allow_stage_change, false);
259
260         if(token=="import")
261                 return parse_import();
262         else if(token=="precision")
263                 return parse_precision();
264         else if(token=="layout")
265         {
266                 RefPtr<Layout> layout = parse_layout();
267                 token = tokenizer.peek_token();
268                 if(is_interface_qualifier(token) && tokenizer.peek_token(1)==";")
269                 {
270                         RefPtr<InterfaceLayout> iface_lo = create_node<InterfaceLayout>();
271                         iface_lo->layout.qualifiers = layout->qualifiers;
272                         iface_lo->interface = tokenizer.parse_token();
273                         tokenizer.expect(";");
274                         return iface_lo;
275                 }
276                 else
277                 {
278                         RefPtr<VariableDeclaration> var = parse_variable_declaration();
279                         var->layout = layout;
280                         return var;
281                 }
282         }
283         else if(token=="typedef")
284                 return parse_type_declaration();
285         else if(token=="struct")
286                 return parse_struct_declaration();
287         else if(is_interface_qualifier(token))
288         {
289                 string next = tokenizer.peek_token(1);
290                 if(is_type(next) || is_qualifier(next))
291                         return parse_variable_declaration();
292                 else
293                         return parse_interface_block();
294         }
295         else if(is_qualifier(token))
296                 return parse_variable_declaration();
297         else if(token=="virtual")
298                 return parse_function_declaration();
299         else if(is_type(token))
300         {
301                 if(tokenizer.peek_token(2)=="(")
302                         return parse_function_declaration();
303                 else
304                         return parse_variable_declaration();
305         }
306         else if(token.empty())
307                 return 0;
308         else
309                 throw parse_error(tokenizer.get_location(), token, "a global declaration");
310 }
311
312 RefPtr<Statement> Parser::parse_statement()
313 {
314         string token = tokenizer.peek_token();
315         if(token=="if")
316                 return parse_conditional();
317         else if(token=="for")
318                 return parse_for();
319         else if(token=="while")
320                 return parse_while();
321         else if(token=="passthrough")
322                 return parse_passthrough();
323         else if(token=="return")
324                 return parse_return();
325         else if(token=="break" || token=="continue" || token=="discard")
326         {
327                 RefPtr<Jump> jump = create_node<Jump>();
328                 jump->keyword = tokenizer.parse_token();
329                 tokenizer.expect(";");
330
331                 return jump;
332         }
333         else if(is_qualifier(token) || is_type(token))
334                 return parse_variable_declaration();
335         else if(token==";")
336         {
337                 tokenizer.parse_token();
338                 throw invalid_shader_source(tokenizer.get_location(), "Empty statement not allowed");
339         }
340         else if(!token.empty())
341         {
342                 RefPtr<ExpressionStatement> expr = create_node<ExpressionStatement>();
343                 expr->expression = parse_expression();
344                 tokenizer.expect(";");
345
346                 return expr;
347         }
348         else
349                 throw parse_error(tokenizer.get_location(), token, "a statement");
350 }
351
352 RefPtr<Import> Parser::parse_import()
353 {
354         if(cur_stage->type!=Stage::SHARED)
355                 throw invalid_shader_source(tokenizer.get_location(), "Imports are only allowed in the shared section");
356
357         tokenizer.expect("import");
358         RefPtr<Import> import = create_node<Import>();
359         import->module = expect_identifier();
360         tokenizer.expect(";");
361         return import;
362 }
363
364 RefPtr<Precision> Parser::parse_precision()
365 {
366         tokenizer.expect("precision");
367         RefPtr<Precision> precision = create_node<Precision>();
368
369         precision->precision = tokenizer.parse_token();
370         if(!is_precision_qualifier(precision->precision))
371                 throw parse_error(tokenizer.get_location(), precision->precision, "a precision qualifier");
372
373         // TODO Add validation for this
374         precision->type = expect_type();
375
376         tokenizer.expect(";");
377
378         return precision;
379 }
380
381 RefPtr<Layout> Parser::parse_layout()
382 {
383         tokenizer.expect("layout");
384         tokenizer.expect("(");
385         RefPtr<Layout> layout = create_node<Layout>();
386         while(1)
387         {
388                 string token = tokenizer.parse_token();
389                 if(token==")")
390                         throw parse_error(tokenizer.get_location(), token, "a layout qualifier name");
391
392                 layout->qualifiers.push_back(Layout::Qualifier());
393                 Layout::Qualifier &qual = layout->qualifiers.back();
394                 qual.name = token;
395
396                 if((qual.has_value = check("=")))
397                 {
398                         if(qual.name=="constant_id" && tokenizer.peek_token()=="auto")
399                         {
400                                 qual.value = -1;
401                                 tokenizer.parse_token();
402                         }
403                         else
404                                 qual.value = expect_integer();
405                 }
406
407                 if(tokenizer.peek_token()==")")
408                         break;
409
410                 tokenizer.expect(",");
411         }
412         tokenizer.expect(")");
413
414         return layout;
415 }
416
417 template<typename T>
418 void Parser::parse_block(Block &block, bool require_braces, RefPtr<T> (Parser::*parse_content)())
419 {
420         bool have_braces = (require_braces || tokenizer.peek_token()=="{");
421         if(have_braces)
422                 tokenizer.expect("{");
423
424         if(have_braces)
425         {
426                 while(tokenizer.peek_token()!="}")
427                         if(RefPtr<Statement> node = parse_with_recovery(parse_content))
428                                 block.body.push_back(node);
429         }
430         else
431                 block.body.push_back((this->*parse_content)());
432
433         block.use_braces = (require_braces || block.body.size()!=1);
434
435         if(have_braces)
436                 tokenizer.expect("}");
437 }
438
439 RefPtr<Expression> Parser::parse_expression(const Operator *outer_oper)
440 {
441         unsigned outer_precedence = (outer_oper ? outer_oper->precedence+(outer_oper->assoc==Operator::RIGHT_TO_LEFT) : 20);
442         RefPtr<Expression> left;
443         VariableReference *left_var = 0;
444         while(1)
445         {
446                 string token = tokenizer.peek_token();
447
448                 const Operator *oper = 0;
449                 for(const Operator *i=Operator::operators; (!oper && i->type); ++i)
450                         if(token==i->token && (!left || i->type!=Operator::PREFIX) && (left || i->type!=Operator::POSTFIX))
451                                 oper = i;
452
453                 bool lower_precedence = (oper && oper->type!=Operator::PREFIX && oper->precedence>=outer_precedence);
454                 if(token==";" || token==")" || token=="]" || token=="," || token==":" || lower_precedence)
455                 {
456                         if(left)
457                                 return left;
458                         else
459                                 throw parse_error(tokenizer.get_location(), token, "an expression");
460                 }
461                 else if(left)
462                 {
463                         if(token=="(")
464                         {
465                                 if(!left_var)
466                                         throw invalid_shader_source(tokenizer.get_location(), "Syntax error before '(': function name must be an identifier");
467                                 left = parse_function_call(*left_var);
468                         }
469                         else if(token==".")
470                         {
471                                 RefPtr<MemberAccess> memacc = create_node<MemberAccess>();
472                                 memacc->left = left;
473                                 memacc->oper = oper;
474                                 tokenizer.parse_token();
475                                 memacc->member = expect_identifier();
476                                 left = memacc;
477                         }
478                         else if(oper && oper->type==Operator::POSTFIX)
479                         {
480                                 RefPtr<UnaryExpression> unary = create_node<UnaryExpression>();
481                                 unary->oper = oper;
482                                 tokenizer.parse_token();
483                                 unary->expression = left;
484                                 left = unary;
485                         }
486                         else if(oper && oper->type==Operator::BINARY)
487                                 left = parse_binary(left, *oper);
488                         else if(oper && oper->type==Operator::TERNARY)
489                                 left = parse_ternary(left, *oper);
490                         else
491                                 throw parse_error(tokenizer.get_location(), token, "an operator");
492                         left_var = 0;
493                 }
494                 else
495                 {
496                         if(token=="(")
497                         {
498                                 tokenizer.parse_token();
499                                 left = parse_expression();
500                                 tokenizer.expect(")");
501                         }
502                         else if(isdigit(token[0]) || token=="true" || token=="false")
503                                 left = parse_literal();
504                         else if(is_identifier(token))
505                         {
506                                 RefPtr<VariableReference> var = create_node<VariableReference>();
507                                 var->name = expect_identifier();
508                                 left = var;
509                                 left_var = var.get();
510                         }
511                         else if(oper && oper->type==Operator::PREFIX)
512                         {
513                                 RefPtr<UnaryExpression> unary = create_node<UnaryExpression>();
514                                 unary->oper = oper;
515                                 tokenizer.parse_token();
516                                 unary->expression = parse_expression(oper);
517                                 left = unary;
518                         }
519                         else
520                                 throw parse_error(tokenizer.get_location(), token, "an expression");
521                 }
522         }
523 }
524
525 RefPtr<Literal> Parser::parse_literal()
526 {
527         RefPtr<Literal> literal = create_node<Literal>();
528         literal->token = tokenizer.parse_token();
529         if(isdigit(literal->token[0]))
530         {
531                 // TODO have the tokenizer return the type of the token
532                 if(isnumrc(literal->token))
533                         literal->value = lexical_cast<int>(literal->token);
534                 else
535                         literal->value = lexical_cast<float>(literal->token);
536         }
537         else if(literal->token=="true" || literal->token=="false")
538                 literal->value = (literal->token=="true");
539         else
540                 throw parse_error(tokenizer.get_location(), literal->token, "a literal");
541
542         return literal;
543 }
544
545 RefPtr<BinaryExpression> Parser::parse_binary(const RefPtr<Expression> &left, const Operator &oper)
546 {
547         RefPtr<BinaryExpression> binary = (oper.precedence==16 ?
548                 static_cast<RefPtr<BinaryExpression> >(create_node<Assignment>()) : create_node<BinaryExpression>());
549         binary->left = left;
550         binary->oper = &oper;
551         tokenizer.expect(oper.token);
552         if(oper.token2[0])
553         {
554                 binary->right = parse_expression();
555                 tokenizer.expect(oper.token2);
556         }
557         else
558                 binary->right = parse_expression(&oper);
559         return binary;
560 }
561
562 RefPtr<TernaryExpression> Parser::parse_ternary(const RefPtr<Expression> &cond, const Operator &oper)
563 {
564         RefPtr<TernaryExpression> ternary = create_node<TernaryExpression>();
565         ternary->condition = cond;
566         ternary->oper = &oper;
567         tokenizer.expect("?");
568         ternary->true_expr = parse_expression(&oper);
569         tokenizer.expect(":");
570         ternary->false_expr = parse_expression(&oper);
571         return ternary;
572 }
573
574 RefPtr<FunctionCall> Parser::parse_function_call(const VariableReference &var)
575 {
576         RefPtr<FunctionCall> call = create_node<FunctionCall>();
577         call->name = var.name;
578         call->oper = &Operator::get_operator("(", Operator::POSTFIX);
579         tokenizer.expect("(");
580         while(tokenizer.peek_token()!=")")
581         {
582                 if(!call->arguments.empty())
583                         tokenizer.expect(",");
584                 call->arguments.push_back(parse_expression());
585         }
586         tokenizer.expect(")");
587         return call;
588 }
589
590 RefPtr<TypeDeclaration> Parser::parse_type_declaration()
591 {
592         tokenizer.expect("typedef");
593
594         RefPtr<TypeDeclaration> type;
595         if(tokenizer.peek_token()=="image")
596                 type = parse_image_type_declaration();
597         else
598                 type = parse_basic_type_declaration();
599
600         tokenizer.expect(";");
601         declared_types.insert(type->name);
602         return type;
603 }
604
605 RefPtr<BasicTypeDeclaration> Parser::parse_basic_type_declaration()
606 {
607         RefPtr<BasicTypeDeclaration> type = create_node<BasicTypeDeclaration>();
608
609         if(tokenizer.peek_token()=="vector")
610         {
611                 type->kind = BasicTypeDeclaration::VECTOR;
612
613                 tokenizer.parse_token();
614                 tokenizer.expect("(");
615                 type->size = expect_integer();
616                 tokenizer.expect(")");
617         }
618
619         type->base = expect_type();
620         type->name = expect_identifier();
621
622         if(type->kind==BasicTypeDeclaration::ALIAS && check("["))
623         {
624                 type->kind = BasicTypeDeclaration::ARRAY;
625                 tokenizer.expect("]");
626         }
627
628         return type;
629 }
630
631 RefPtr<ImageTypeDeclaration> Parser::parse_image_type_declaration()
632 {
633         tokenizer.expect("image");
634         tokenizer.expect("(");
635
636         RefPtr<ImageTypeDeclaration> type = create_node<ImageTypeDeclaration>();
637         while(1)
638         {
639                 string token = tokenizer.parse_token();
640                 if(token=="dimensions")
641                 {
642                         tokenizer.expect("=");
643                         token = tokenizer.parse_token();
644                         if(token=="1")
645                                 type->dimensions = ImageTypeDeclaration::ONE;
646                         else if(token=="2")
647                                 type->dimensions = ImageTypeDeclaration::TWO;
648                         else if(token=="3")
649                                 type->dimensions = ImageTypeDeclaration::THREE;
650                         else if(token=="cube")
651                                 type->dimensions = ImageTypeDeclaration::CUBE;
652                         else
653                                 throw parse_error(tokenizer.get_location(), token, "dimensions");
654
655                         if(check("["))
656                         {
657                                 type->array = true;
658                                 tokenizer.expect("]");
659                         }
660                 }
661                 else if(token=="sampled")
662                         type->sampled = true;
663                 else if(token=="shadow")
664                         type->shadow = true;
665                 else
666                         throw parse_error(tokenizer.get_location(), token, "image type attribute");
667
668                 token = tokenizer.peek_token();
669                 if(token==")")
670                         break;
671
672                 tokenizer.expect(",");
673         }
674         tokenizer.expect(")");
675
676         type->base = expect_type();
677         type->name = expect_identifier();
678
679         return type;
680 }
681
682 RefPtr<StructDeclaration> Parser::parse_struct_declaration()
683 {
684         tokenizer.expect("struct");
685         RefPtr<StructDeclaration> strct = create_node<StructDeclaration>();
686
687         strct->name = expect_identifier();
688         parse_block(strct->members, true, &Parser::parse_variable_declaration);
689         tokenizer.expect(";");
690
691         declared_types.insert(strct->name);
692         return strct;
693 }
694
695 RefPtr<VariableDeclaration> Parser::parse_variable_declaration()
696 {
697         RefPtr<VariableDeclaration> var = create_node<VariableDeclaration>();
698
699         string token = tokenizer.peek_token();
700         while(is_qualifier(token))
701         {
702                 tokenizer.parse_token();
703                 if(is_interface_qualifier(token))
704                         var->interface = token;
705                 else if(is_sampling_qualifier(token))
706                         var->sampling = token;
707                 else if(is_interpolation_qualifier(token))
708                         var->interpolation = token;
709                 else if(is_precision_qualifier(token))
710                         var->precision = token;
711                 else if(token=="const")
712                         var->constant = true;
713                 token = tokenizer.peek_token();
714         }
715
716         var->type = expect_type();
717         var->name = expect_identifier();
718
719         if(check("["))
720         {
721                 var->array = true;
722                 if(!check("]"))
723                 {
724                         var->array_size = parse_expression();
725                         tokenizer.expect("]");
726                 }
727         }
728
729         if(check("="))
730                 var->init_expression = parse_expression();
731
732         tokenizer.expect(";");
733         return var;
734 }
735
736 RefPtr<VariableDeclaration> Parser::parse_variable_declaration_with_layout()
737 {
738         RefPtr<Layout> layout;
739         if(tokenizer.peek_token()=="layout")
740                 layout = parse_layout();
741
742         RefPtr<VariableDeclaration> var = parse_variable_declaration();
743         var->layout = layout;
744
745         return var;
746 }
747
748 RefPtr<FunctionDeclaration> Parser::parse_function_declaration()
749 {
750         RefPtr<FunctionDeclaration> func = create_node<FunctionDeclaration>();
751
752         func->virtua = check("virtual");
753         func->return_type = expect_type();
754         func->name = expect_identifier();
755         tokenizer.expect("(");
756         while(tokenizer.peek_token()!=")")
757         {
758                 if(!func->parameters.empty())
759                         tokenizer.expect(",");
760
761                 RefPtr<VariableDeclaration> var = create_node<VariableDeclaration>();
762                 string token = tokenizer.peek_token();
763                 if(token=="in" || token=="out" || token=="inout")
764                         var->interface = tokenizer.parse_token();
765                 var->type = expect_type();
766                 var->name = expect_identifier();
767                 func->parameters.push_back(var);
768         }
769         tokenizer.expect(")");
770
771         func->overrd = check("override");
772
773         string token = tokenizer.peek_token();
774         if(token=="{")
775         {
776                 func->definition = func.get();
777                 parse_block(func->body, true, &Parser::parse_statement);
778         }
779         else if(token==";")
780                 tokenizer.parse_token();
781         else
782                 throw parse_error(tokenizer.get_location(), token, "'{' or ';'");
783
784         return func;
785 }
786
787 RefPtr<InterfaceBlock> Parser::parse_interface_block()
788 {
789         RefPtr<InterfaceBlock> iface = create_node<InterfaceBlock>();
790
791         iface->interface = tokenizer.parse_token();
792         if(!is_interface_qualifier(iface->interface))
793                 throw parse_error(tokenizer.get_location(), iface->interface, "an interface qualifier");
794
795         iface->block_name = expect_identifier();
796         iface->members = new Block;
797         parse_block(*iface->members, true, &Parser::parse_variable_declaration_with_layout);
798         if(!check(";"))
799         {
800                 iface->instance_name = expect_identifier();
801                 if(check("["))
802                 {
803                         iface->array = true;
804                         tokenizer.expect("]");
805                 }
806                 tokenizer.expect(";");
807         }
808
809         return iface;
810 }
811
812 RefPtr<Conditional> Parser::parse_conditional()
813 {
814         tokenizer.expect("if");
815         RefPtr<Conditional> cond = create_node<Conditional>();
816         tokenizer.expect("(");
817         cond->condition = parse_expression();
818         tokenizer.expect(")");
819
820         parse_block(cond->body, false, &Parser::parse_statement);
821
822         string token = tokenizer.peek_token();
823         if(token=="else")
824         {
825                 tokenizer.parse_token();
826                 parse_block(cond->else_body, false, &Parser::parse_statement);
827         }
828
829         return cond;
830 }
831
832 RefPtr<Iteration> Parser::parse_for()
833 {
834         tokenizer.expect("for");
835         RefPtr<Iteration> loop = create_node<Iteration>();
836         tokenizer.expect("(");
837         string token = tokenizer.peek_token();
838         if(is_type(token))
839                 loop->init_statement = parse_statement();
840         else
841         {
842                 if(token!=";")
843                 {
844                         RefPtr<ExpressionStatement> expr = create_node<ExpressionStatement>();
845                         expr->expression = parse_expression();
846                         loop->init_statement = expr;
847                 }
848                 tokenizer.expect(";");
849         }
850         if(tokenizer.peek_token()!=";")
851                 loop->condition = parse_expression();
852         tokenizer.expect(";");
853         if(tokenizer.peek_token()!=")")
854                 loop->loop_expression = parse_expression();
855         tokenizer.expect(")");
856
857         parse_block(loop->body, false, &Parser::parse_statement);
858
859         return loop;
860 }
861
862 RefPtr<Iteration> Parser::parse_while()
863 {
864         tokenizer.expect("while");
865         RefPtr<Iteration> loop = create_node<Iteration>();
866         tokenizer.expect("(");
867         loop->condition = parse_expression();
868         tokenizer.expect(")");
869
870         parse_block(loop->body, false, &Parser::parse_statement);
871
872         return loop;
873 }
874
875 RefPtr<Passthrough> Parser::parse_passthrough()
876 {
877         tokenizer.expect("passthrough");
878         RefPtr<Passthrough> pass = create_node<Passthrough>();
879         if(cur_stage->type==Stage::GEOMETRY)
880         {
881                 tokenizer.expect("[");
882                 pass->subscript = parse_expression();
883                 tokenizer.expect("]");
884         }
885         tokenizer.expect(";");
886         return pass;
887 }
888
889 RefPtr<Return> Parser::parse_return()
890 {
891         tokenizer.expect("return");
892         RefPtr<Return> ret = create_node<Return>();
893         if(tokenizer.peek_token()!=";")
894                 ret->expression = parse_expression();
895         tokenizer.expect(";");
896         return ret;
897 }
898
899 } // namespace SL
900 } // namespace GL
901 } // namespace Msp