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Remove unused functions from the shader source
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1 #include <msp/core/raii.h>
2 #include <msp/strings/format.h>
3 #include <msp/strings/utils.h>
4 #include "error.h"
5 #include "program.h"
6 #include "programcompiler.h"
7 #include "resources.h"
8 #include "shader.h"
9
10 using namespace std;
11
12 namespace {
13
14 const char builtins_src[] =
15         "////// vertex\n"
16         "out gl_PerVertex {\n"
17         "  vec4 gl_Position;\n"
18         "  float gl_ClipDistance[];\n"
19         "};"
20         "////// geometry\n"
21         "in gl_PerVertex {\n"
22         "  vec4 gl_Position;\n"
23         "  float gl_ClipDistance[];\n"
24         "} gl_in[];\n"
25         "out gl_PerVertex {\n"
26         "  vec4 gl_Position;\n"
27         "  float gl_ClipDistance[];\n"
28         "};\n";
29
30 }
31
32 namespace Msp {
33 namespace GL {
34
35 using namespace ProgramSyntax;
36
37 ProgramCompiler::ProgramCompiler():
38         resources(0),
39         module(0)
40 { }
41
42 void ProgramCompiler::compile(const string &source)
43 {
44         resources = 0;
45         module = &parser.parse(source);
46         process();
47 }
48
49 void ProgramCompiler::compile(IO::Base &io, Resources *res)
50 {
51         resources = res;
52         module = &parser.parse(io);
53         process();
54 }
55
56 void ProgramCompiler::add_shaders(Program &program)
57 {
58         if(!module)
59                 throw invalid_operation("ProgramCompiler::add_shaders");
60
61         string head = "#version 150\n";
62         for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
63         {
64                 if(i->type==VERTEX)
65                         program.attach_shader_owned(new VertexShader(head+apply<Formatter>(*i)));
66                 else if(i->type==GEOMETRY)
67                         program.attach_shader_owned(new GeometryShader(head+apply<Formatter>(*i)));
68                 else if(i->type==FRAGMENT)
69                         program.attach_shader_owned(new FragmentShader(head+apply<Formatter>(*i)));
70         }
71
72         program.bind_attribute(VERTEX4, "vertex");
73         program.bind_attribute(NORMAL3, "normal");
74         program.bind_attribute(COLOR4_FLOAT, "color");
75         program.bind_attribute(TEXCOORD4, "texcoord");
76 }
77
78 Module *ProgramCompiler::create_builtins_module()
79 {
80         ProgramParser parser;
81         Module *module = new Module(parser.parse(builtins_src));
82         for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
83         {
84                 VariableResolver resolver;
85                 i->content.visit(resolver);
86                 for(map<string, VariableDeclaration *>::iterator j=i->content.variables.begin(); j!=i->content.variables.end(); ++j)
87                         j->second->linked_declaration = j->second;
88         }
89         return module;
90 }
91
92 Module &ProgramCompiler::get_builtins_module()
93 {
94         static RefPtr<Module> builtins_module = create_builtins_module();
95         return *builtins_module;
96 }
97
98 Stage *ProgramCompiler::get_builtins(StageType type)
99 {
100         Module &module = get_builtins_module();
101         for(list<Stage>::iterator i=module.stages.begin(); i!=module.stages.end(); ++i)
102                 if(i->type==type)
103                         return &*i;
104         return 0;
105 }
106
107 void ProgramCompiler::process()
108 {
109         list<Import *> imports = apply<NodeGatherer<Import> >(module->shared);
110         for(list<Import *>::iterator i=imports.end(); i!=imports.begin(); )
111                 import((*--i)->module);
112         apply<NodeRemover>(module->shared, set<Node *>(imports.begin(), imports.end()));
113
114         for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
115                 generate(*i);
116         for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); )
117         {
118                 if(optimize(*i))
119                         i = module->stages.begin();
120                 else
121                         ++i;
122         }
123 }
124
125 void ProgramCompiler::import(const string &name)
126 {
127         if(!resources)
128                 throw runtime_error("no resources");
129         RefPtr<IO::Seekable> io = resources->open_raw(name+".glsl");
130         if(!io)
131                 throw runtime_error(format("module %s not found", name));
132         ProgramParser import_parser;
133         Module &imported_module = import_parser.parse(*io);
134
135         inject_block(module->shared.content, imported_module.shared.content);
136         apply<DeclarationCombiner>(module->shared);
137         for(list<Stage>::iterator i=imported_module.stages.begin(); i!=imported_module.stages.end(); ++i)
138         {
139                 list<Stage>::iterator j;
140                 for(j=module->stages.begin(); (j!=module->stages.end() && j->type<i->type); ++j) ;
141                 if(j==module->stages.end() || j->type>i->type)
142                 {
143                         j = module->stages.insert(j, *i);
144                         list<Stage>::iterator k = j;
145                         if(++k!=module->stages.end())
146                                 k->previous = &*j;
147                         if(j!=module->stages.begin())
148                                 j->previous = &*--(k=j);
149                 }
150                 else
151                 {
152                         inject_block(j->content, i->content);
153                         apply<DeclarationCombiner>(*j);
154                 }
155         }
156 }
157
158 void ProgramCompiler::generate(Stage &stage)
159 {
160         inject_block(stage.content, module->shared.content);
161
162         apply<FunctionResolver>(stage);
163         apply<VariableResolver>(stage);
164         apply<InterfaceGenerator>(stage);
165         apply<VariableResolver>(stage);
166         apply<VariableRenamer>(stage);
167 }
168
169 bool ProgramCompiler::optimize(Stage &stage)
170 {
171         apply<ConstantConditionEliminator>(stage);
172         apply<VariableResolver>(stage);
173
174         set<Node *> unused = apply<UnusedVariableLocator>(stage);
175         set<Node *> unused2 = apply<UnusedFunctionLocator>(stage);
176         unused.insert(unused2.begin(), unused2.end());
177         apply<NodeRemover>(stage, unused);
178
179         return !unused.empty();
180 }
181
182 void ProgramCompiler::inject_block(Block &target, const Block &source)
183 {
184         list<NodePtr<Node> >::iterator insert_point = target.body.begin();
185         for(list<NodePtr<Node> >::const_iterator i=source.body.begin(); i!=source.body.end(); ++i)
186                 target.body.insert(insert_point, (*i)->clone());
187 }
188
189 template<typename T>
190 typename T::ResultType ProgramCompiler::apply(Stage &stage)
191 {
192         T visitor;
193         visitor.apply(stage);
194         return visitor.get_result();
195 }
196
197 template<typename T, typename A>
198 typename T::ResultType ProgramCompiler::apply(Stage &stage, const A &arg)
199 {
200         T visitor(arg);
201         visitor.apply(stage);
202         return visitor.get_result();
203 }
204
205
206 ProgramCompiler::Visitor::Visitor():
207         stage(0)
208 { }
209
210 void ProgramCompiler::Visitor::apply(Stage &s)
211 {
212         SetForScope<Stage *> set(stage, &s);
213         stage->content.visit(*this);
214 }
215
216
217 ProgramCompiler::Formatter::Formatter():
218         indent(0),
219         parameter_list(false),
220         else_if(0)
221 { }
222
223 void ProgramCompiler::Formatter::visit(Literal &literal)
224 {
225         formatted += literal.token;
226 }
227
228 void ProgramCompiler::Formatter::visit(ParenthesizedExpression &parexpr)
229 {
230         formatted += '(';
231         parexpr.expression->visit(*this);
232         formatted += ')';
233 }
234
235 void ProgramCompiler::Formatter::visit(VariableReference &var)
236 {
237         formatted += var.name;
238 }
239
240 void ProgramCompiler::Formatter::visit(MemberAccess &memacc)
241 {
242         memacc.left->visit(*this);
243         formatted += format(".%s", memacc.member);
244 }
245
246 void ProgramCompiler::Formatter::visit(UnaryExpression &unary)
247 {
248         if(unary.prefix)
249                 formatted += unary.oper;
250         unary.expression->visit(*this);
251         if(!unary.prefix)
252                 formatted += unary.oper;
253 }
254
255 void ProgramCompiler::Formatter::visit(BinaryExpression &binary)
256 {
257         binary.left->visit(*this);
258         formatted += binary.oper;
259         binary.right->visit(*this);
260         formatted += binary.after;
261 }
262
263 void ProgramCompiler::Formatter::visit(Assignment &assign)
264 {
265         assign.left->visit(*this);
266         formatted += format(" %s ", assign.oper);
267         assign.right->visit(*this);
268 }
269
270 void ProgramCompiler::Formatter::visit(FunctionCall &call)
271 {
272         formatted += format("%s(", call.name);
273         for(vector<NodePtr<Expression> >::iterator i=call.arguments.begin(); i!=call.arguments.end(); ++i)
274         {
275                 if(i!=call.arguments.begin())
276                         formatted += ", ";
277                 (*i)->visit(*this);
278         }
279         formatted += ')';
280 }
281
282 void ProgramCompiler::Formatter::visit(ExpressionStatement &expr)
283 {
284         expr.expression->visit(*this);
285         formatted += ';';
286 }
287
288 void ProgramCompiler::Formatter::visit(Block &block)
289 {
290         if(else_if)
291                 --else_if;
292
293         unsigned brace_indent = indent;
294         bool use_braces = (block.use_braces || (indent && block.body.size()!=1));
295         if(use_braces)
296                 formatted += format("%s{\n", string(brace_indent*2, ' '));
297
298         SetForScope<unsigned> set(indent, indent+!formatted.empty());
299         string spaces(indent*2, ' ');
300         for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); ++i)
301         {
302                 if(i!=block.body.begin())
303                         formatted += '\n';
304                 formatted += spaces;
305                 (*i)->visit(*this);
306                 else_if = 0;
307         }
308
309         if(use_braces)
310                 formatted += format("\n%s}", string(brace_indent*2, ' '));
311 }
312
313 void ProgramCompiler::Formatter::visit(Import &import)
314 {
315         formatted += format("import %s;", import.module);
316 }
317
318 void ProgramCompiler::Formatter::visit(Layout &layout)
319 {
320         formatted += "layout(";
321         for(vector<Layout::Qualifier>::const_iterator i=layout.qualifiers.begin(); i!=layout.qualifiers.end(); ++i)
322         {
323                 if(i!=layout.qualifiers.begin())
324                         formatted += ", ";
325                 formatted += i->identifier;
326                 if(!i->value.empty())
327                         formatted += format("=%s", i->value);
328         }
329         formatted += format(") %s;", layout.interface);
330 }
331
332 void ProgramCompiler::Formatter::visit(StructDeclaration &strct)
333 {
334         formatted += format("struct %s\n", strct.name);
335         strct.members.visit(*this);
336         formatted += ';';
337 }
338
339 void ProgramCompiler::Formatter::visit(VariableDeclaration &var)
340 {
341         if(var.constant)
342                 formatted += "const ";
343         if(!var.sampling.empty())
344                 formatted += format("%s ", var.sampling);
345         if(!var.interface.empty() && var.interface!=block_interface)
346                 formatted += format("%s ", var.interface);
347         formatted += format("%s %s", var.type, var.name);
348         if(var.array)
349         {
350                 formatted += '[';
351                 if(var.array_size)
352                         var.array_size->visit(*this);
353                 formatted += ']';
354         }
355         if(var.init_expression)
356         {
357                 formatted += " = ";
358                 var.init_expression->visit(*this);
359         }
360         if(!parameter_list)
361                 formatted += ';';
362 }
363
364 void ProgramCompiler::Formatter::visit(InterfaceBlock &iface)
365 {
366         SetForScope<string> set(block_interface, iface.interface);
367         formatted += format("%s %s\n", iface.interface, iface.name);
368         iface.members.visit(*this);
369         formatted += ';';
370 }
371
372 void ProgramCompiler::Formatter::visit(FunctionDeclaration &func)
373 {
374         formatted += format("%s %s(", func.return_type, func.name);
375         for(vector<NodePtr<VariableDeclaration> >::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
376         {
377                 if(i!=func.parameters.begin())
378                         formatted += ", ";
379                 SetFlag set(parameter_list);
380                 (*i)->visit(*this);
381         }
382         formatted += ')';
383         if(func.definition==&func)
384         {
385                 formatted += '\n';
386                 func.body.visit(*this);
387         }
388         else
389                 formatted += ';';
390 }
391
392 void ProgramCompiler::Formatter::visit(Conditional &cond)
393 {
394         if(else_if)
395                 formatted.replace(formatted.rfind('\n'), string::npos, 1, ' ');
396
397         indent -= else_if;
398
399         formatted += "if(";
400         cond.condition->visit(*this);
401         formatted += ")\n";
402
403         cond.body.visit(*this);
404         if(!cond.else_body.body.empty())
405         {
406                 formatted += format("\n%selse\n", string(indent*2, ' '));
407                 SetForScope<unsigned> set(else_if, 2);
408                 cond.else_body.visit(*this);
409         }
410 }
411
412 void ProgramCompiler::Formatter::visit(Iteration &iter)
413 {
414         formatted += "for(";
415         iter.init_statement->visit(*this);
416         formatted += ' ';
417         iter.condition->visit(*this);
418         formatted += "; ";
419         iter.loop_expression->visit(*this);
420         formatted += ")\n";
421         iter.body.visit(*this);
422 }
423
424 void ProgramCompiler::Formatter::visit(Return &ret)
425 {
426         formatted += "return ";
427         ret.expression->visit(*this);
428         formatted += ';';
429 }
430
431
432 ProgramCompiler::DeclarationCombiner::DeclarationCombiner():
433         toplevel(true),
434         remove_node(false)
435 { }
436
437 void ProgramCompiler::DeclarationCombiner::visit(Block &block)
438 {
439         if(!toplevel)
440                 return;
441
442         SetForScope<bool> set(toplevel, false);
443         for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
444         {
445                 remove_node = false;
446                 (*i)->visit(*this);
447                 if(remove_node)
448                         block.body.erase(i++);
449                 else
450                         ++i;
451         }
452 }
453
454 void ProgramCompiler::DeclarationCombiner::visit(FunctionDeclaration &func)
455 {
456         vector<FunctionDeclaration *> &decls = functions[func.name];
457         if(func.definition)
458         {
459                 for(vector<FunctionDeclaration *>::iterator i=decls.begin(); i!=decls.end(); ++i)
460                 {
461                         (*i)->definition = func.definition;
462                         (*i)->body.body.clear();
463                 }
464         }
465         decls.push_back(&func);
466 }
467
468 void ProgramCompiler::DeclarationCombiner::visit(VariableDeclaration &var)
469 {
470         VariableDeclaration *&ptr = variables[var.name];
471         if(ptr)
472         {
473                 if(var.init_expression)
474                         ptr->init_expression = var.init_expression;
475                 remove_node = true;
476         }
477         else
478                 ptr = &var;
479 }
480
481
482 ProgramCompiler::VariableResolver::VariableResolver():
483         anonymous(false),
484         record_target(false),
485         assignment_target(0),
486         self_referencing(false)
487 { }
488
489 void ProgramCompiler::VariableResolver::apply(Stage &s)
490 {
491         SetForScope<Stage *> set(stage, &s);
492         Stage *builtins = get_builtins(stage->type);
493         if(builtins)
494                 blocks.push_back(&builtins->content);
495         stage->content.visit(*this);
496         if(builtins)
497                 blocks.pop_back();
498 }
499
500 void ProgramCompiler::VariableResolver::visit(Block &block)
501 {
502         blocks.push_back(&block);
503         block.variables.clear();
504         TraversingVisitor::visit(block);
505         blocks.pop_back();
506 }
507
508 void ProgramCompiler::VariableResolver::visit(VariableReference &var)
509 {
510         var.declaration = 0;
511         type = 0;
512         for(vector<Block *>::iterator i=blocks.end(); i!=blocks.begin(); )
513         {
514                 --i;
515                 map<string, VariableDeclaration *>::iterator j = (*i)->variables.find(var.name);
516                 if(j!=(*i)->variables.end())
517                 {
518                         var.declaration = j->second;
519                         type = j->second->type_declaration;
520                         break;
521                 }
522         }
523
524         if(record_target)
525         {
526                 if(assignment_target)
527                 {
528                         record_target = false;
529                         assignment_target = 0;
530                 }
531                 else
532                         assignment_target = var.declaration;
533         }
534         else if(var.declaration && var.declaration==assignment_target)
535                 self_referencing = true;
536 }
537
538 void ProgramCompiler::VariableResolver::visit(MemberAccess &memacc)
539 {
540         type = 0;
541         TraversingVisitor::visit(memacc);
542         memacc.declaration = 0;
543         if(type)
544         {
545                 map<string, VariableDeclaration *>::iterator i = type->members.variables.find(memacc.member);
546                 if(i!=type->members.variables.end())
547                 {
548                         memacc.declaration = i->second;
549                         type = i->second->type_declaration;
550                 }
551                 else
552                         type = 0;
553         }
554 }
555
556 void ProgramCompiler::VariableResolver::visit(BinaryExpression &binary)
557 {
558         if(binary.oper=="[")
559         {
560                 {
561                         SetForScope<bool> set(record_target, false);
562                         binary.right->visit(*this);
563                 }
564                 type = 0;
565                 binary.left->visit(*this);
566         }
567         else
568         {
569                 TraversingVisitor::visit(binary);
570                 type = 0;
571         }
572 }
573
574 void ProgramCompiler::VariableResolver::visit(Assignment &assign)
575 {
576         {
577                 SetFlag set(record_target);
578                 assignment_target = 0;
579                 assign.left->visit(*this);
580         }
581
582         self_referencing = false;
583         assign.right->visit(*this);
584
585         assign.self_referencing = (self_referencing || assign.oper!="=");
586         assign.target_declaration = assignment_target;
587 }
588
589 void ProgramCompiler::VariableResolver::visit(StructDeclaration &strct)
590 {
591         TraversingVisitor::visit(strct);
592         blocks.back()->types[strct.name] = &strct;
593 }
594
595 void ProgramCompiler::VariableResolver::visit(VariableDeclaration &var)
596 {
597         for(vector<Block *>::iterator i=blocks.end(); i!=blocks.begin(); )
598         {
599                 --i;
600                 map<string, StructDeclaration *>::iterator j = (*i)->types.find(var.type);
601                 if(j!=(*i)->types.end())
602                         var.type_declaration = j->second;
603         }
604
605         if(!block_interface.empty() && var.interface.empty())
606                 var.interface = block_interface;
607
608         TraversingVisitor::visit(var);
609         blocks.back()->variables[var.name] = &var;
610         if(anonymous && blocks.size()>1)
611                 blocks[blocks.size()-2]->variables[var.name] = &var;
612 }
613
614 void ProgramCompiler::VariableResolver::visit(InterfaceBlock &iface)
615 {
616         SetFlag set(anonymous);
617         SetForScope<string> set2(block_interface, iface.interface);
618         TraversingVisitor::visit(iface);
619 }
620
621
622 void ProgramCompiler::FunctionResolver::visit(FunctionCall &call)
623 {
624         map<string, vector<FunctionDeclaration *> >::iterator i = functions.find(call.name);
625         if(i!=functions.end())
626                 call.declaration = i->second.back();
627
628         TraversingVisitor::visit(call);
629 }
630
631 void ProgramCompiler::FunctionResolver::visit(FunctionDeclaration &func)
632 {
633         vector<FunctionDeclaration *> &decls = functions[func.name];
634         if(func.definition)
635         {
636                 for(vector<FunctionDeclaration *>::iterator i=decls.begin(); i!=decls.end(); ++i)
637                         (*i)->definition = func.definition;
638                 decls.clear();
639                 decls.push_back(&func);
640         }
641         else if(!decls.empty() && decls.back()->definition)
642                 func.definition = decls.back()->definition;
643         else
644                 decls.push_back(&func);
645
646         TraversingVisitor::visit(func);
647 }
648
649
650 ProgramCompiler::InterfaceGenerator::InterfaceGenerator():
651         scope_level(0),
652         remove_node(false)
653 { }
654
655 string ProgramCompiler::InterfaceGenerator::get_out_prefix(StageType type)
656 {
657         if(type==VERTEX)
658                 return "_vs_out_";
659         else if(type==GEOMETRY)
660                 return "_gs_out_";
661         else
662                 return string();
663 }
664
665 void ProgramCompiler::InterfaceGenerator::apply(Stage &s)
666 {
667         SetForScope<Stage *> set(stage, &s);
668         if(stage->previous)
669                 in_prefix = get_out_prefix(stage->previous->type);
670         out_prefix = get_out_prefix(stage->type);
671         stage->content.visit(*this);
672 }
673
674 void ProgramCompiler::InterfaceGenerator::visit(Block &block)
675 {
676         SetForScope<unsigned> set(scope_level, scope_level+1);
677         for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
678         {
679                 (*i)->visit(*this);
680
681                 if(scope_level==1)
682                 {
683                         for(map<string, VariableDeclaration *>::iterator j=iface_declarations.begin(); j!=iface_declarations.end(); ++j)
684                         {
685                                 list<NodePtr<Node> >::iterator k = block.body.insert(i, j->second);
686                                 (*k)->visit(*this);
687                         }
688                         iface_declarations.clear();
689                 }
690
691                 for(list<Node *>::iterator j=insert_nodes.begin(); j!=insert_nodes.end(); ++j)
692                         block.body.insert(i, *j);
693                 insert_nodes.clear();
694
695                 if(remove_node)
696                         block.body.erase(i++);
697                 else
698                         ++i;
699                 remove_node = false;
700         }
701 }
702
703 string ProgramCompiler::InterfaceGenerator::change_prefix(const string &name, const string &prefix) const
704 {
705         unsigned offset = (name.compare(0, in_prefix.size(), in_prefix) ? 0 : in_prefix.size());
706         return prefix+name.substr(offset);
707 }
708
709 bool ProgramCompiler::InterfaceGenerator::generate_interface(VariableDeclaration &var, const string &iface, const string &name)
710 {
711         const map<string, VariableDeclaration *> &stage_vars = (iface=="in" ? stage->in_variables : stage->out_variables);
712         if(stage_vars.count(name) || iface_declarations.count(name))
713                 return false;
714
715         VariableDeclaration* iface_var = new VariableDeclaration;
716         iface_var->sampling = var.sampling;
717         iface_var->interface = iface;
718         iface_var->type = var.type;
719         iface_var->type_declaration = var.type_declaration;
720         iface_var->name = name;
721         if(stage->type==GEOMETRY)
722                 iface_var->array = ((var.array && var.interface!="in") || iface=="in");
723         else
724                 iface_var->array = var.array;
725         if(iface_var->array)
726                 iface_var->array_size = var.array_size;
727         if(iface=="in")
728                 iface_var->linked_declaration = &var;
729         iface_declarations[name] = iface_var;
730
731         return true;
732 }
733
734 void ProgramCompiler::InterfaceGenerator::insert_assignment(const string &left, ProgramSyntax::Expression *right)
735 {
736         Assignment *assign = new Assignment;
737         VariableReference *ref = new VariableReference;
738         ref->name = left;
739         assign->left = ref;
740         assign->oper = "=";
741         assign->right = right;
742
743         ExpressionStatement *stmt = new ExpressionStatement;
744         stmt->expression = assign;
745         insert_nodes.push_back(stmt);
746 }
747
748 void ProgramCompiler::InterfaceGenerator::visit(VariableReference &var)
749 {
750         if(var.declaration || !stage->previous)
751                 return;
752         if(iface_declarations.count(var.name))
753                 return;
754
755         const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
756         map<string, VariableDeclaration *>::const_iterator i = prev_out.find(var.name);
757         if(i==prev_out.end())
758                 i = prev_out.find(in_prefix+var.name);
759         if(i!=prev_out.end())
760                 generate_interface(*i->second, "in", var.name);
761 }
762
763 void ProgramCompiler::InterfaceGenerator::visit(VariableDeclaration &var)
764 {
765         if(var.interface=="out")
766         {
767                 if(scope_level==1)
768                         stage->out_variables[var.name] = &var;
769                 else if(generate_interface(var, "out", change_prefix(var.name, string())))
770                 {
771                         remove_node = true;
772                         if(var.init_expression)
773                                 insert_assignment(var.name, var.init_expression->clone());
774                 }
775         }
776         else if(var.interface=="in")
777         {
778                 stage->in_variables[var.name] = &var;
779                 if(var.linked_declaration)
780                         var.linked_declaration->linked_declaration = &var;
781                 else if(stage->previous)
782                 {
783                         const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
784                         map<string, VariableDeclaration *>::const_iterator i = prev_out.find(var.name);
785                         if(i!=prev_out.end())
786                         {
787                                 var.linked_declaration = i->second;
788                                 i->second->linked_declaration = &var;
789                         }
790                 }
791         }
792
793         TraversingVisitor::visit(var);
794 }
795
796 void ProgramCompiler::InterfaceGenerator::visit(Passthrough &pass)
797 {
798         vector<VariableDeclaration *> pass_vars;
799
800         for(map<string, VariableDeclaration *>::const_iterator i=stage->in_variables.begin(); i!=stage->in_variables.end(); ++i)
801                 pass_vars.push_back(i->second);
802         for(map<string, VariableDeclaration *>::const_iterator i=iface_declarations.begin(); i!=iface_declarations.end(); ++i)
803                 if(i->second->interface=="in")
804                         pass_vars.push_back(i->second);
805
806         if(stage->previous)
807         {
808                 const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
809                 for(map<string, VariableDeclaration *>::const_iterator i=prev_out.begin(); i!=prev_out.end(); ++i)
810                 {
811                         bool linked = false;
812                         for(vector<VariableDeclaration *>::const_iterator j=pass_vars.begin(); (!linked && j!=pass_vars.end()); ++j)
813                                 linked = ((*j)->linked_declaration==i->second);
814
815                         if(!linked && generate_interface(*i->second, "in", i->second->name))
816                                 pass_vars.push_back(i->second);
817                 }
818         }
819
820         if(stage->type==GEOMETRY)
821         {
822                 VariableReference *ref = new VariableReference;
823                 ref->name = "gl_in";
824
825                 BinaryExpression *subscript = new BinaryExpression;
826                 subscript->left = ref;
827                 subscript->oper = "[";
828                 subscript->right = pass.subscript;
829                 subscript->after = "]";
830
831                 MemberAccess *memacc = new MemberAccess;
832                 memacc->left = subscript;
833                 memacc->member = "gl_Position";
834
835                 insert_assignment("gl_Position", memacc);
836         }
837
838         for(vector<VariableDeclaration *>::const_iterator i=pass_vars.begin(); i!=pass_vars.end(); ++i)
839         {
840                 string out_name = change_prefix((*i)->name, out_prefix);
841                 generate_interface(**i, "out", out_name);
842
843                 VariableReference *ref = new VariableReference;
844                 ref->name = (*i)->name;
845                 if(pass.subscript)
846                 {
847                         BinaryExpression *subscript = new BinaryExpression;
848                         subscript->left = ref;
849                         subscript->oper = "[";
850                         subscript->right = pass.subscript;
851                         subscript->after = "]";
852                         insert_assignment(out_name, subscript);
853                 }
854                 else
855                         insert_assignment(out_name, ref);
856         }
857
858         remove_node = true;
859 }
860
861
862 void ProgramCompiler::VariableRenamer::visit(VariableReference &var)
863 {
864         if(var.declaration)
865                 var.name = var.declaration->name;
866 }
867
868 void ProgramCompiler::VariableRenamer::visit(VariableDeclaration &var)
869 {
870         if(var.linked_declaration)
871                 var.name = var.linked_declaration->name;
872         TraversingVisitor::visit(var);
873 }
874
875
876 ProgramCompiler::ExpressionEvaluator::ExpressionEvaluator():
877         variable_values(0),
878         result(0.0f),
879         result_valid(false)
880 { }
881
882 ProgramCompiler::ExpressionEvaluator::ExpressionEvaluator(const ValueMap &v):
883         variable_values(&v),
884         result(0.0f),
885         result_valid(false)
886 { }
887
888 void ProgramCompiler::ExpressionEvaluator::visit(Literal &literal)
889 {
890         if(literal.token=="true")
891                 result = 1.0f;
892         else if(literal.token=="false")
893                 result = 0.0f;
894         else
895                 result = lexical_cast<float>(literal.token);
896         result_valid = true;
897 }
898
899 void ProgramCompiler::ExpressionEvaluator::visit(VariableReference &var)
900 {
901         if(!var.declaration)
902                 return;
903
904         if(variable_values)
905         {
906                 ValueMap::const_iterator i = variable_values->find(var.declaration);
907                 if(i!=variable_values->end())
908                         i->second->visit(*this);
909         }
910         else if(var.declaration->init_expression)
911                 var.declaration->init_expression->visit(*this);
912 }
913
914 void ProgramCompiler::ExpressionEvaluator::visit(UnaryExpression &unary)
915 {
916         result_valid = false;
917         unary.expression->visit(*this);
918         if(!result_valid)
919                 return;
920
921         if(unary.oper=="!")
922                 result = !result;
923         else
924                 result_valid = false;
925 }
926
927 void ProgramCompiler::ExpressionEvaluator::visit(BinaryExpression &binary)
928 {
929         result_valid = false;
930         binary.left->visit(*this);
931         if(!result_valid)
932                 return;
933
934         float left_result = result;
935         result_valid = false;
936         binary.right->visit(*this);
937         if(!result_valid)
938                 return;
939
940         if(binary.oper=="<")
941                 result = (left_result<result);
942         else if(binary.oper=="<=")
943                 result = (left_result<=result);
944         else if(binary.oper==">")
945                 result = (left_result>result);
946         else if(binary.oper==">=")
947                 result = (left_result>=result);
948         else if(binary.oper=="==")
949                 result = (left_result==result);
950         else if(binary.oper=="!=")
951                 result = (left_result!=result);
952         else if(binary.oper=="&&")
953                 result = (left_result && result);
954         else if(binary.oper=="||")
955                 result = (left_result || result);
956         else
957                 result_valid = false;
958 }
959
960
961 ProgramCompiler::ConstantConditionEliminator::ConstantConditionEliminator():
962         scope_level(0),
963         remove_node(false),
964         replacement_block(0)
965 { }
966
967 void ProgramCompiler::ConstantConditionEliminator::visit(Block &block)
968 {
969         SetForScope<unsigned> set(scope_level, scope_level+1);
970         for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
971         {
972                 (*i)->visit(*this);
973                 if(replacement_block)
974                 {
975                         for(list<NodePtr<Node> >::iterator j=replacement_block->body.begin(); j!=replacement_block->body.end(); ++j)
976                                 block.body.insert(i, *j);
977                         replacement_block = 0;
978                 }
979
980                 if(remove_node)
981                         block.body.erase(i++);
982                 else
983                         ++i;
984                 remove_node = false;
985         }
986
987         for(map<string, VariableDeclaration *>::const_iterator i=block.variables.begin(); i!=block.variables.end(); ++i)
988                 variable_values.erase(i->second);
989 }
990
991 void ProgramCompiler::ConstantConditionEliminator::visit(Assignment &assign)
992 {
993         variable_values.erase(assign.target_declaration);
994 }
995
996 void ProgramCompiler::ConstantConditionEliminator::visit(VariableDeclaration &var)
997 {
998         if(var.constant || scope_level>1)
999                 variable_values[&var] = &*var.init_expression;
1000 }
1001
1002 void ProgramCompiler::ConstantConditionEliminator::visit(Conditional &cond)
1003 {
1004         ExpressionEvaluator eval(variable_values);
1005         cond.condition->visit(eval);
1006         if(eval.result_valid)
1007         {
1008                 remove_node = true;
1009                 replacement_block = (eval.result ? &cond.body : &cond.else_body);
1010         }
1011         else
1012                 TraversingVisitor::visit(cond);
1013 }
1014
1015 void ProgramCompiler::ConstantConditionEliminator::visit(Iteration &iter)
1016 {
1017         if(iter.condition)
1018         {
1019                 ExpressionEvaluator eval;
1020                 iter.condition->visit(eval);
1021                 if(eval.result_valid && !eval.result)
1022                 {
1023                         remove_node = true;
1024                         return;
1025                 }
1026         }
1027
1028         TraversingVisitor::visit(iter);
1029 }
1030
1031
1032 ProgramCompiler::UnusedVariableLocator::UnusedVariableLocator():
1033         aggregate(0),
1034         assignment(0),
1035         assignment_target(false)
1036 { }
1037
1038 void ProgramCompiler::UnusedVariableLocator::apply(Stage &s)
1039 {
1040         assignments.push_back(BlockAssignmentMap());
1041         Visitor::apply(s);
1042         assignments.pop_back();
1043 }
1044
1045 void ProgramCompiler::UnusedVariableLocator::visit(VariableReference &var)
1046 {
1047         unused_nodes.erase(var.declaration);
1048
1049         map<VariableDeclaration *, Node *>::iterator i = aggregates.find(var.declaration);
1050         if(i!=aggregates.end())
1051                 unused_nodes.erase(i->second);
1052
1053         if(assignment_target)
1054                 return;
1055
1056         for(vector<BlockAssignmentMap>::iterator j=assignments.end(); j!=assignments.begin(); )
1057         {
1058                 --j;
1059                 BlockAssignmentMap::iterator k = j->find(var.declaration);
1060                 if(k!=j->end())
1061                 {
1062                         for(vector<Node *>::iterator l=k->second.nodes.begin(); l!=k->second.nodes.end(); ++l)
1063                                 unused_nodes.erase(*l);
1064                         j->erase(k);
1065                         break;
1066                 }
1067         }
1068 }
1069
1070 void ProgramCompiler::UnusedVariableLocator::visit(MemberAccess &memacc)
1071 {
1072         TraversingVisitor::visit(memacc);
1073         unused_nodes.erase(memacc.declaration);
1074 }
1075
1076 void ProgramCompiler::UnusedVariableLocator::visit(BinaryExpression &binary)
1077 {
1078         if(binary.oper=="[")
1079         {
1080                 binary.left->visit(*this);
1081                 SetForScope<bool> set(assignment_target, false);
1082                 binary.right->visit(*this);
1083         }
1084         else
1085                 TraversingVisitor::visit(binary);
1086 }
1087
1088 void ProgramCompiler::UnusedVariableLocator::visit(Assignment &assign)
1089 {
1090         {
1091                 SetForScope<bool> set(assignment_target, !assign.self_referencing);
1092                 assign.left->visit(*this);
1093         }
1094         assign.right->visit(*this);
1095         assignment = &assign;
1096 }
1097
1098 void ProgramCompiler::UnusedVariableLocator::record_assignment(VariableDeclaration &var, Node &node, bool self_ref)
1099 {
1100         unused_nodes.insert(&node);
1101         BlockAssignmentMap &block_assignments = assignments.back();
1102         AssignmentList &var_assignments = block_assignments[&var];
1103         if(!self_ref)
1104                 var_assignments.nodes.clear();
1105         var_assignments.nodes.push_back(&node);
1106         var_assignments.conditional = false;
1107         var_assignments.self_referencing = self_ref;
1108 }
1109
1110 void ProgramCompiler::UnusedVariableLocator::visit(ExpressionStatement &expr)
1111 {
1112         assignment = 0;
1113         TraversingVisitor::visit(expr);
1114         if(assignment && assignment->target_declaration)
1115                 record_assignment(*assignment->target_declaration, expr, assignment->self_referencing);
1116 }
1117
1118 void ProgramCompiler::UnusedVariableLocator::visit(StructDeclaration &strct)
1119 {
1120         SetForScope<Node *> set(aggregate, &strct);
1121         unused_nodes.insert(&strct);
1122         TraversingVisitor::visit(strct);
1123 }
1124
1125 void ProgramCompiler::UnusedVariableLocator::visit(VariableDeclaration &var)
1126 {
1127         if(aggregate)
1128                 aggregates[&var] = aggregate;
1129         else
1130         {
1131                 unused_nodes.insert(&var);
1132                 if(var.init_expression)
1133                         record_assignment(var, *var.init_expression, false);
1134         }
1135         unused_nodes.erase(var.type_declaration);
1136         TraversingVisitor::visit(var);
1137 }
1138
1139 void ProgramCompiler::UnusedVariableLocator::visit(InterfaceBlock &iface)
1140 {
1141         SetForScope<Node *> set(aggregate, &iface);
1142         unused_nodes.insert(&iface);
1143         TraversingVisitor::visit(iface);
1144 }
1145
1146 void ProgramCompiler::UnusedVariableLocator::visit(FunctionDeclaration &func)
1147 {
1148         assignments.push_back(BlockAssignmentMap());
1149
1150         for(vector<NodePtr<VariableDeclaration> >::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
1151                 (*i)->visit(*this);
1152         func.body.visit(*this);
1153
1154         BlockAssignmentMap &block_assignments = assignments.back();
1155         for(map<string, VariableDeclaration *>::iterator i=func.body.variables.begin(); i!=func.body.variables.end(); ++i)
1156                 block_assignments.erase(i->second);
1157         for(BlockAssignmentMap::iterator i=block_assignments.begin(); i!=block_assignments.end(); ++i)
1158         {
1159                 if(i->first->interface=="out" && stage->type!=FRAGMENT && !i->first->linked_declaration)
1160                         continue;
1161
1162                 for(vector<Node *>::iterator j=i->second.nodes.begin(); j!=i->second.nodes.end(); ++j)
1163                         unused_nodes.erase(*j);
1164         }
1165
1166         assignments.pop_back();
1167 }
1168
1169 void ProgramCompiler::UnusedVariableLocator::merge_down_assignments()
1170 {
1171         BlockAssignmentMap &parent_assignments = assignments[assignments.size()-2];
1172         BlockAssignmentMap &block_assignments = assignments.back();
1173         for(BlockAssignmentMap::iterator i=block_assignments.begin(); i!=block_assignments.end(); ++i)
1174         {
1175                 BlockAssignmentMap::iterator j = parent_assignments.find(i->first);
1176                 if(j==parent_assignments.end())
1177                         parent_assignments.insert(*i);
1178                 else if(i->second.self_referencing || i->second.conditional)
1179                 {
1180                         j->second.nodes.insert(j->second.nodes.end(), i->second.nodes.begin(), i->second.nodes.end());
1181                         j->second.conditional |= i->second.conditional;
1182                         j->second.self_referencing |= i->second.self_referencing;
1183                 }
1184                 else
1185                         j->second = i->second;
1186         }
1187         assignments.pop_back();
1188 }
1189
1190 void ProgramCompiler::UnusedVariableLocator::visit(Conditional &cond)
1191 {
1192         cond.condition->visit(*this);
1193         assignments.push_back(BlockAssignmentMap());
1194         cond.body.visit(*this);
1195
1196         BlockAssignmentMap if_assignments;
1197         swap(assignments.back(), if_assignments);
1198         cond.else_body.visit(*this);
1199
1200         BlockAssignmentMap &else_assignments = assignments.back();
1201         for(BlockAssignmentMap::iterator i=else_assignments.begin(); i!=else_assignments.end(); ++i)
1202         {
1203                 BlockAssignmentMap::iterator j = if_assignments.find(i->first);
1204                 if(j!=if_assignments.end())
1205                 {
1206                         i->second.nodes.insert(i->second.nodes.end(), j->second.nodes.begin(), j->second.nodes.end());
1207                         i->second.conditional |= j->second.conditional;
1208                         i->second.self_referencing |= j->second.self_referencing;
1209                         if_assignments.erase(j);
1210                 }
1211                 else
1212                         i->second.conditional = true;
1213         }
1214
1215         for(BlockAssignmentMap::iterator i=if_assignments.begin(); i!=if_assignments.end(); ++i)
1216         {
1217                 i->second.conditional = true;
1218                 else_assignments.insert(*i);
1219         }
1220
1221         merge_down_assignments();
1222 }
1223
1224 void ProgramCompiler::UnusedVariableLocator::visit(Iteration &iter)
1225 {
1226         assignments.push_back(BlockAssignmentMap());
1227         TraversingVisitor::visit(iter);
1228         merge_down_assignments();
1229 }
1230
1231
1232 void ProgramCompiler::UnusedFunctionLocator::visit(FunctionCall &call)
1233 {
1234         TraversingVisitor::visit(call);
1235
1236         unused_nodes.erase(call.declaration);
1237         if(call.declaration && call.declaration->definition!=call.declaration)
1238                 used_definitions.insert(call.declaration->definition);
1239 }
1240
1241 void ProgramCompiler::UnusedFunctionLocator::visit(FunctionDeclaration &func)
1242 {
1243         TraversingVisitor::visit(func);
1244
1245         if(func.name!="main" && !used_definitions.count(&func))
1246                 unused_nodes.insert(&func);
1247 }
1248
1249
1250 ProgramCompiler::NodeRemover::NodeRemover(const set<Node *> &r):
1251         to_remove(r)
1252 { }
1253
1254 void ProgramCompiler::NodeRemover::visit(Block &block)
1255 {
1256         for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
1257         {
1258                 (*i)->visit(*this);
1259                 if(to_remove.count(&**i))
1260                         block.body.erase(i++);
1261                 else
1262                         ++i;
1263         }
1264 }
1265
1266 void ProgramCompiler::NodeRemover::visit(VariableDeclaration &var)
1267 {
1268         if(to_remove.count(&var))
1269         {
1270                 stage->in_variables.erase(var.name);
1271                 stage->out_variables.erase(var.name);
1272                 if(var.linked_declaration)
1273                         var.linked_declaration->linked_declaration = 0;
1274         }
1275         else if(var.init_expression && to_remove.count(&*var.init_expression))
1276                 var.init_expression = 0;
1277 }
1278
1279 } // namespace GL
1280 } // namespace Msp