source/programcompiler.cpp

   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 "shader.h"
   8
   9 using namespace std;
  10
  11 namespace {
  12
  13 const char builtins_src[] =
  14         "////// vertex\n"
  15         "out gl_PerVertex {\n"
  16         "  vec4 gl_Position;\n"
  17         "  float gl_ClipDistance[];\n"
  18         "};"
  19         "////// geometry\n"
  20         "in gl_PerVertex {\n"
  21         "  vec4 gl_Position;\n"
  22         "  float gl_ClipDistance[];\n"
  23         "} gl_in[];\n"
  24         "out gl_PerVertex {\n"
  25         "  vec4 gl_Position;\n"
  26         "  float gl_ClipDistance[];\n"
  27         "};\n";
  28
  29 }
  30
  31 namespace Msp {
  32 namespace GL {
  33
  34 using namespace ProgramSyntax;
  35
  36 ProgramCompiler::ProgramCompiler():
  37         module(0)
  38 { }
  39
  40 void ProgramCompiler::compile(const string &source)
  41 {
  42         module = &parser.parse(source);
  43         process();
  44 }
  45
  46 void ProgramCompiler::compile(IO::Base &io)
  47 {
  48         module = &parser.parse(io);
  49         process();
  50 }
  51
  52 void ProgramCompiler::add_shaders(Program &program)
  53 {
  54         if(!module)
  55                 throw invalid_operation("ProgramCompiler::add_shaders");
  56
  57         string head = "#version 150\n";
  58         for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
  59         {
  60                 if(i->type==VERTEX)
  61                         program.attach_shader_owned(new VertexShader(head+create_source(*i)));
  62                 else if(i->type==GEOMETRY)
  63                         program.attach_shader_owned(new GeometryShader(head+create_source(*i)));
  64                 else if(i->type==FRAGMENT)
  65                         program.attach_shader_owned(new FragmentShader(head+create_source(*i)));
  66         }
  67
  68         program.bind_attribute(VERTEX4, "vertex");
  69         program.bind_attribute(NORMAL3, "normal");
  70         program.bind_attribute(COLOR4_FLOAT, "color");
  71         program.bind_attribute(TEXCOORD4, "texcoord");
  72 }
  73
  74 Module *ProgramCompiler::create_builtins_module()
  75 {
  76         ProgramParser parser;
  77         Module *module = new Module(parser.parse(builtins_src));
  78         for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
  79         {
  80                 VariableResolver resolver;
  81                 i->content.visit(resolver);
  82                 for(map<string, VariableDeclaration *>::iterator j=i->content.variables.begin(); j!=i->content.variables.end(); ++j)
  83                         j->second->linked_declaration = j->second;
  84         }
  85         return module;
  86 }
  87
  88 Module &ProgramCompiler::get_builtins_module()
  89 {
  90         static RefPtr<Module> builtins_module = create_builtins_module();
  91         return *builtins_module;
  92 }
  93
  94 Stage *ProgramCompiler::get_builtins(StageType type)
  95 {
  96         Module &module = get_builtins_module();
  97         for(list<Stage>::iterator i=module.stages.begin(); i!=module.stages.end(); ++i)
  98                 if(i->type==type)
  99                         return &*i;
 100         return 0;
 101 }
 102
 103 void ProgramCompiler::process()
 104 {
 105         for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
 106                 generate(*i);
 107         for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); )
 108         {
 109                 if(optimize(*i))
 110                         i = module->stages.begin();
 111                 else
 112                         ++i;
 113         }
 114 }
 115
 116 void ProgramCompiler::generate(Stage &stage)
 117 {
 118         inject_block(stage.content, module->shared.content);
 119
 120         apply<VariableResolver>(stage);
 121         apply<InterfaceGenerator>(stage);
 122         apply<VariableResolver>(stage);
 123         apply<VariableRenamer>(stage);
 124 }
 125
 126 bool ProgramCompiler::optimize(Stage &stage)
 127 {
 128         UnusedVariableLocator unused_locator;
 129         unused_locator.apply(stage);
 130
 131         NodeRemover remover;
 132         remover.to_remove = unused_locator.unused_nodes;
 133         remover.apply(stage);
 134
 135         return !unused_locator.unused_nodes.empty();
 136 }
 137
 138 void ProgramCompiler::inject_block(Block &target, const Block &source)
 139 {
 140         list<NodePtr<Node> >::iterator insert_point = target.body.begin();
 141         for(list<NodePtr<Node> >::const_iterator i=source.body.begin(); i!=source.body.end(); ++i)
 142                 target.body.insert(insert_point, (*i)->clone());
 143 }
 144
 145 template<typename T>
 146 void ProgramCompiler::apply(Stage &stage)
 147 {
 148         T visitor;
 149         visitor.apply(stage);
 150 }
 151
 152 string ProgramCompiler::create_source(Stage &stage)
 153 {
 154         Formatter formatter;
 155         formatter.apply(stage);
 156         return formatter.formatted;
 157 }
 158
 159
 160 ProgramCompiler::Visitor::Visitor():
 161         stage(0)
 162 { }
 163
 164 void ProgramCompiler::Visitor::apply(Stage &s)
 165 {
 166         SetForScope<Stage *> set(stage, &s);
 167         stage->content.visit(*this);
 168 }
 169
 170
 171 ProgramCompiler::Formatter::Formatter():
 172         indent(0),
 173         parameter_list(false),
 174         else_if(false)
 175 { }
 176
 177 void ProgramCompiler::Formatter::visit(Literal &literal)
 178 {
 179         formatted += literal.token;
 180 }
 181
 182 void ProgramCompiler::Formatter::visit(ParenthesizedExpression &parexpr)
 183 {
 184         formatted += '(';
 185         parexpr.expression->visit(*this);
 186         formatted += ')';
 187 }
 188
 189 void ProgramCompiler::Formatter::visit(VariableReference &var)
 190 {
 191         formatted += var.name;
 192 }
 193
 194 void ProgramCompiler::Formatter::visit(MemberAccess &memacc)
 195 {
 196         memacc.left->visit(*this);
 197         formatted += format(".%s", memacc.member);
 198 }
 199
 200 void ProgramCompiler::Formatter::visit(UnaryExpression &unary)
 201 {
 202         if(unary.prefix)
 203                 formatted += unary.oper;
 204         unary.expression->visit(*this);
 205         if(!unary.prefix)
 206                 formatted += unary.oper;
 207 }
 208
 209 void ProgramCompiler::Formatter::visit(BinaryExpression &binary)
 210 {
 211         binary.left->visit(*this);
 212         if(binary.assignment)
 213                 formatted += format(" %s ", binary.oper);
 214         else
 215                 formatted += binary.oper;
 216         binary.right->visit(*this);
 217         formatted += binary.after;
 218 }
 219
 220 void ProgramCompiler::Formatter::visit(FunctionCall &call)
 221 {
 222         formatted += format("%s(", call.name);
 223         for(vector<NodePtr<Expression> >::iterator i=call.arguments.begin(); i!=call.arguments.end(); ++i)
 224         {
 225                 if(i!=call.arguments.begin())
 226                         formatted += ", ";
 227                 (*i)->visit(*this);
 228         }
 229         formatted += ')';
 230 }
 231
 232 void ProgramCompiler::Formatter::visit(ExpressionStatement &expr)
 233 {
 234         expr.expression->visit(*this);
 235         formatted += ';';
 236 }
 237
 238 void ProgramCompiler::Formatter::visit(Block &block)
 239 {
 240         if(block.use_braces)
 241         {
 242                 if(else_if)
 243                 {
 244                         formatted += '\n';
 245                         else_if = false;
 246                 }
 247                 formatted += format("%s{\n", string(indent*2, ' '));
 248         }
 249
 250         bool change_indent = (!formatted.empty() && !else_if);
 251         indent += change_indent;
 252         string spaces(indent*2, ' ');
 253         for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); ++i)
 254         {
 255                 if(i!=block.body.begin())
 256                         formatted += '\n';
 257                 if(!else_if)
 258                         formatted += spaces;
 259                 (*i)->visit(*this);
 260         }
 261         indent -= change_indent;
 262
 263         if(block.use_braces)
 264                 formatted += format("\n%s}", string(indent*2, ' '));
 265 }
 266
 267 void ProgramCompiler::Formatter::visit(Layout &layout)
 268 {
 269         formatted += "layout(";
 270         for(vector<Layout::Qualifier>::const_iterator i=layout.qualifiers.begin(); i!=layout.qualifiers.end(); ++i)
 271         {
 272                 if(i!=layout.qualifiers.begin())
 273                         formatted += ", ";
 274                 formatted += i->identifier;
 275                 if(!i->value.empty())
 276                         formatted += format("=%s", i->value);
 277         }
 278         formatted += format(") %s;", layout.interface);
 279 }
 280
 281 void ProgramCompiler::Formatter::visit(StructDeclaration &strct)
 282 {
 283         formatted += format("struct %s\n", strct.name);
 284         strct.members.visit(*this);
 285         formatted += ';';
 286 }
 287
 288 void ProgramCompiler::Formatter::visit(VariableDeclaration &var)
 289 {
 290         if(var.constant)
 291                 formatted += "const ";
 292         if(!var.sampling.empty())
 293                 formatted += format("%s ", var.sampling);
 294         if(!var.interface.empty() && var.interface!=block_interface)
 295                 formatted += format("%s ", var.interface);
 296         formatted += format("%s %s", var.type, var.name);
 297         if(var.array)
 298         {
 299                 formatted += '[';
 300                 if(var.array_size)
 301                         var.array_size->visit(*this);
 302                 formatted += ']';
 303         }
 304         if(var.init_expression)
 305         {
 306                 formatted += " = ";
 307                 var.init_expression->visit(*this);
 308         }
 309         if(!parameter_list)
 310                 formatted += ';';
 311 }
 312
 313 void ProgramCompiler::Formatter::visit(InterfaceBlock &iface)
 314 {
 315         SetForScope<string> set(block_interface, iface.interface);
 316         formatted += format("%s %s\n", iface.interface, iface.name);
 317         iface.members.visit(*this);
 318         formatted += ';';
 319 }
 320
 321 void ProgramCompiler::Formatter::visit(FunctionDeclaration &func)
 322 {
 323         formatted += format("%s %s(", func.return_type, func.name);
 324         for(vector<NodePtr<VariableDeclaration> >::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
 325         {
 326                 if(i!=func.parameters.begin())
 327                         formatted += ", ";
 328                 SetFlag set(parameter_list);
 329                 (*i)->visit(*this);
 330         }
 331         formatted += ')';
 332         if(func.definition)
 333         {
 334                 formatted += '\n';
 335                 func.body.visit(*this);
 336         }
 337         else
 338                 formatted += ';';
 339 }
 340
 341 void ProgramCompiler::Formatter::visit(Conditional &cond)
 342 {
 343         if(else_if)
 344         {
 345                 formatted += ' ';
 346                 else_if = false;
 347         }
 348
 349         formatted += "if(";
 350         cond.condition->visit(*this);
 351         formatted += ")\n";
 352
 353         cond.body.visit(*this);
 354         if(!cond.else_body.body.empty())
 355         {
 356                 formatted += format("\n%selse", string(indent*2, ' '));
 357                 SetFlag set(else_if);
 358                 cond.else_body.visit(*this);
 359         }
 360 }
 361
 362 void ProgramCompiler::Formatter::visit(Iteration &iter)
 363 {
 364         formatted += "for(";
 365         iter.init_statement->visit(*this);
 366         formatted += ' ';
 367         iter.condition->visit(*this);
 368         formatted += "; ";
 369         iter.loop_expression->visit(*this);
 370         formatted += ")\n";
 371         iter.body.visit(*this);
 372 }
 373
 374 void ProgramCompiler::Formatter::visit(Return &ret)
 375 {
 376         formatted += "return ";
 377         ret.expression->visit(*this);
 378         formatted += ';';
 379 }
 380
 381
 382 ProgramCompiler::VariableResolver::VariableResolver():
 383         anonymous(false)
 384 { }
 385
 386 void ProgramCompiler::VariableResolver::apply(Stage &s)
 387 {
 388         SetForScope<Stage *> set(stage, &s);
 389         Stage *builtins = get_builtins(stage->type);
 390         if(builtins)
 391                 blocks.push_back(&builtins->content);
 392         stage->content.visit(*this);
 393         if(builtins)
 394                 blocks.pop_back();
 395 }
 396
 397 void ProgramCompiler::VariableResolver::visit(Block &block)
 398 {
 399         blocks.push_back(&block);
 400         block.variables.clear();
 401         TraversingVisitor::visit(block);
 402         blocks.pop_back();
 403 }
 404
 405 void ProgramCompiler::VariableResolver::visit(VariableReference &var)
 406 {
 407         var.declaration = 0;
 408         type = 0;
 409         for(vector<Block *>::iterator i=blocks.end(); i!=blocks.begin(); )
 410         {
 411                 --i;
 412                 map<string, VariableDeclaration *>::iterator j = (*i)->variables.find(var.name);
 413                 if(j!=(*i)->variables.end())
 414                 {
 415                         var.declaration = j->second;
 416                         type = j->second->type_declaration;
 417                         break;
 418                 }
 419         }
 420 }
 421
 422 void ProgramCompiler::VariableResolver::visit(MemberAccess &memacc)
 423 {
 424         type = 0;
 425         TraversingVisitor::visit(memacc);
 426         memacc.declaration = 0;
 427         if(type)
 428         {
 429                 map<string, VariableDeclaration *>::iterator i = type->members.variables.find(memacc.member);
 430                 if(i!=type->members.variables.end())
 431                 {
 432                         memacc.declaration = i->second;
 433                         type = i->second->type_declaration;
 434                 }
 435                 else
 436                         type = 0;
 437         }
 438 }
 439
 440 void ProgramCompiler::VariableResolver::visit(BinaryExpression &binary)
 441 {
 442         if(binary.oper=="[")
 443         {
 444                 binary.right->visit(*this);
 445                 type = 0;
 446                 binary.left->visit(*this);
 447         }
 448         else
 449         {
 450                 TraversingVisitor::visit(binary);
 451                 type = 0;
 452         }
 453 }
 454
 455 void ProgramCompiler::VariableResolver::visit(StructDeclaration &strct)
 456 {
 457         TraversingVisitor::visit(strct);
 458         blocks.back()->types[strct.name] = &strct;
 459 }
 460
 461 void ProgramCompiler::VariableResolver::visit(VariableDeclaration &var)
 462 {
 463         for(vector<Block *>::iterator i=blocks.end(); i!=blocks.begin(); )
 464         {
 465                 --i;
 466                 map<string, StructDeclaration *>::iterator j = (*i)->types.find(var.type);
 467                 if(j!=(*i)->types.end())
 468                         var.type_declaration = j->second;
 469         }
 470
 471         if(!block_interface.empty() && var.interface.empty())
 472                 var.interface = block_interface;
 473
 474         TraversingVisitor::visit(var);
 475         blocks.back()->variables[var.name] = &var;
 476         if(anonymous && blocks.size()>1)
 477                 blocks[blocks.size()-2]->variables[var.name] = &var;
 478 }
 479
 480 void ProgramCompiler::VariableResolver::visit(InterfaceBlock &iface)
 481 {
 482         SetFlag set(anonymous);
 483         SetForScope<string> set2(block_interface, iface.interface);
 484         TraversingVisitor::visit(iface);
 485 }
 486
 487
 488 ProgramCompiler::InterfaceGenerator::InterfaceGenerator():
 489         scope_level(0),
 490         remove_node(false)
 491 { }
 492
 493 string ProgramCompiler::InterfaceGenerator::get_out_prefix(StageType type)
 494 {
 495         if(type==VERTEX)
 496                 return "_vs_out_";
 497         else if(type==GEOMETRY)
 498                 return "_gs_out_";
 499         else
 500                 return string();
 501 }
 502
 503 void ProgramCompiler::InterfaceGenerator::apply(Stage &s)
 504 {
 505         SetForScope<Stage *> set(stage, &s);
 506         if(stage->previous)
 507                 in_prefix = get_out_prefix(stage->previous->type);
 508         out_prefix = get_out_prefix(stage->type);
 509         stage->content.visit(*this);
 510 }
 511
 512 void ProgramCompiler::InterfaceGenerator::visit(Block &block)
 513 {
 514         SetForScope<unsigned> set(scope_level, scope_level+1);
 515         for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
 516         {
 517                 (*i)->visit(*this);
 518
 519                 if(scope_level==1)
 520                 {
 521                         for(map<string, VariableDeclaration *>::iterator j=iface_declarations.begin(); j!=iface_declarations.end(); ++j)
 522                         {
 523                                 list<NodePtr<Node> >::iterator k = block.body.insert(i, j->second);
 524                                 (*k)->visit(*this);
 525                         }
 526                         iface_declarations.clear();
 527                 }
 528
 529                 for(list<Node *>::iterator j=insert_nodes.begin(); j!=insert_nodes.end(); ++j)
 530                         block.body.insert(i, *j);
 531                 insert_nodes.clear();
 532
 533                 if(remove_node)
 534                         block.body.erase(i++);
 535                 else
 536                         ++i;
 537                 remove_node = false;
 538         }
 539 }
 540
 541 string ProgramCompiler::InterfaceGenerator::change_prefix(const string &name, const string &prefix) const
 542 {
 543         unsigned offset = (name.compare(0, in_prefix.size(), in_prefix) ? 0 : in_prefix.size());
 544         return prefix+name.substr(offset);
 545 }
 546
 547 bool ProgramCompiler::InterfaceGenerator::generate_interface(VariableDeclaration &var, const string &iface, const string &name)
 548 {
 549         const map<string, VariableDeclaration *> &stage_vars = (iface=="in" ? stage->in_variables : stage->out_variables);
 550         if(stage_vars.count(name) || iface_declarations.count(name))
 551                 return false;
 552
 553         VariableDeclaration* iface_var = new VariableDeclaration;
 554         iface_var->sampling = var.sampling;
 555         iface_var->interface = iface;
 556         iface_var->type = var.type;
 557         iface_var->type_declaration = var.type_declaration;
 558         iface_var->name = name;
 559         if(stage->type==GEOMETRY)
 560                 iface_var->array = ((var.array && var.interface!="in") || iface=="in");
 561         else
 562                 iface_var->array = var.array;
 563         if(iface_var->array)
 564                 iface_var->array_size = var.array_size;
 565         if(iface=="in")
 566                 iface_var->linked_declaration = &var;
 567         iface_declarations[name] = iface_var;
 568
 569         return true;
 570 }
 571
 572 void ProgramCompiler::InterfaceGenerator::insert_assignment(const string &left, ProgramSyntax::Expression *right)
 573 {
 574         BinaryExpression *assign = new BinaryExpression;
 575         VariableReference *ref = new VariableReference;
 576         ref->name = left;
 577         assign->left = ref;
 578         assign->oper = "=";
 579         assign->right = right;
 580         assign->assignment = true;
 581
 582         ExpressionStatement *stmt = new ExpressionStatement;
 583         stmt->expression = assign;
 584         insert_nodes.push_back(stmt);
 585 }
 586
 587 void ProgramCompiler::InterfaceGenerator::visit(VariableReference &var)
 588 {
 589         if(var.declaration || !stage->previous)
 590                 return;
 591         if(iface_declarations.count(var.name))
 592                 return;
 593
 594         const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
 595         map<string, VariableDeclaration *>::const_iterator i = prev_out.find(var.name);
 596         if(i==prev_out.end())
 597                 i = prev_out.find(in_prefix+var.name);
 598         if(i!=prev_out.end())
 599                 generate_interface(*i->second, "in", var.name);
 600 }
 601
 602 void ProgramCompiler::InterfaceGenerator::visit(VariableDeclaration &var)
 603 {
 604         if(var.interface=="out")
 605         {
 606                 if(scope_level==1)
 607                         stage->out_variables[var.name] = &var;
 608                 else if(generate_interface(var, "out", change_prefix(var.name, string())))
 609                 {
 610                         remove_node = true;
 611                         if(var.init_expression)
 612                                 insert_assignment(var.name, var.init_expression->clone());
 613                 }
 614         }
 615         else if(var.interface=="in")
 616         {
 617                 stage->in_variables[var.name] = &var;
 618                 if(var.linked_declaration)
 619                         var.linked_declaration->linked_declaration = &var;
 620                 else if(stage->previous)
 621                 {
 622                         const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
 623                         map<string, VariableDeclaration *>::const_iterator i = prev_out.find(var.name);
 624                         if(i!=prev_out.end())
 625                         {
 626                                 var.linked_declaration = i->second;
 627                                 i->second->linked_declaration = &var;
 628                         }
 629                 }
 630         }
 631
 632         TraversingVisitor::visit(var);
 633 }
 634
 635 void ProgramCompiler::InterfaceGenerator::visit(Passthrough &pass)
 636 {
 637         vector<VariableDeclaration *> pass_vars;
 638
 639         for(map<string, VariableDeclaration *>::const_iterator i=stage->in_variables.begin(); i!=stage->in_variables.end(); ++i)
 640                 pass_vars.push_back(i->second);
 641         for(map<string, VariableDeclaration *>::const_iterator i=iface_declarations.begin(); i!=iface_declarations.end(); ++i)
 642                 if(i->second->interface=="in")
 643                         pass_vars.push_back(i->second);
 644
 645         if(stage->previous)
 646         {
 647                 const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
 648                 for(map<string, VariableDeclaration *>::const_iterator i=prev_out.begin(); i!=prev_out.end(); ++i)
 649                 {
 650                         bool linked = false;
 651                         for(vector<VariableDeclaration *>::const_iterator j=pass_vars.begin(); (!linked && j!=pass_vars.end()); ++j)
 652                                 linked = ((*j)->linked_declaration==i->second);
 653
 654                         if(!linked && generate_interface(*i->second, "in", i->second->name))
 655                                 pass_vars.push_back(i->second);
 656                 }
 657         }
 658
 659         if(stage->type==GEOMETRY)
 660         {
 661                 VariableReference *ref = new VariableReference;
 662                 ref->name = "gl_in";
 663
 664                 BinaryExpression *subscript = new BinaryExpression;
 665                 subscript->left = ref;
 666                 subscript->oper = "[";
 667                 subscript->right = pass.subscript;
 668                 subscript->after = "]";
 669
 670                 MemberAccess *memacc = new MemberAccess;
 671                 memacc->left = subscript;
 672                 memacc->member = "gl_Position";
 673
 674                 insert_assignment("gl_Position", memacc);
 675         }
 676
 677         for(vector<VariableDeclaration *>::const_iterator i=pass_vars.begin(); i!=pass_vars.end(); ++i)
 678         {
 679                 string out_name = change_prefix((*i)->name, out_prefix);
 680                 generate_interface(**i, "out", out_name);
 681
 682                 VariableReference *ref = new VariableReference;
 683                 ref->name = (*i)->name;
 684                 if(pass.subscript)
 685                 {
 686                         BinaryExpression *subscript = new BinaryExpression;
 687                         subscript->left = ref;
 688                         subscript->oper = "[";
 689                         subscript->right = pass.subscript;
 690                         subscript->after = "]";
 691                         insert_assignment(out_name, subscript);
 692                 }
 693                 else
 694                         insert_assignment(out_name, ref);
 695         }
 696
 697         remove_node = true;
 698 }
 699
 700
 701 void ProgramCompiler::VariableRenamer::visit(VariableReference &var)
 702 {
 703         if(var.declaration)
 704                 var.name = var.declaration->name;
 705 }
 706
 707 void ProgramCompiler::VariableRenamer::visit(VariableDeclaration &var)
 708 {
 709         if(var.linked_declaration)
 710                 var.name = var.linked_declaration->name;
 711         TraversingVisitor::visit(var);
 712 }
 713
 714
 715 ProgramCompiler::UnusedVariableLocator::UnusedVariableLocator():
 716         aggregate(0),
 717         assignment(false),
 718         record_target(false),
 719         assignment_target(0),
 720         indeterminate_target(false),
 721         self_referencing(false)
 722 { }
 723
 724 void ProgramCompiler::UnusedVariableLocator::visit(VariableReference &var)
 725 {
 726         if(record_target)
 727         {
 728                 if(assignment_target)
 729                         indeterminate_target = true;
 730                 else
 731                         assignment_target = var.declaration;
 732         }
 733         else
 734         {
 735                 unused_nodes.erase(var.declaration);
 736
 737                 map<VariableDeclaration *, Node *>::iterator i = assignments.find(var.declaration);
 738                 if(i!=assignments.end())
 739                 {
 740                         unused_nodes.erase(i->second);
 741                         assignments.erase(i);
 742                 }
 743
 744                 if(assignment && var.declaration==assignment_target)
 745                         self_referencing = true;
 746         }
 747
 748         map<VariableDeclaration *, Node *>::iterator i = aggregates.find(var.declaration);
 749         if(i!=aggregates.end())
 750                 unused_nodes.erase(i->second);
 751 }
 752
 753 void ProgramCompiler::UnusedVariableLocator::visit(MemberAccess &memacc)
 754 {
 755         TraversingVisitor::visit(memacc);
 756         unused_nodes.erase(memacc.declaration);
 757 }
 758
 759 void ProgramCompiler::UnusedVariableLocator::visit(BinaryExpression &binary)
 760 {
 761         if(binary.assignment)
 762         {
 763                 assignment = true;
 764                 {
 765                         SetFlag set(record_target);
 766                         binary.left->visit(*this);
 767                 }
 768                 if(binary.oper!="=")
 769                         self_referencing = true;
 770                 binary.right->visit(*this);
 771         }
 772         else if(record_target && binary.oper=="[")
 773         {
 774                 binary.left->visit(*this);
 775                 SetForScope<bool> set(record_target, false);
 776                 binary.right->visit(*this);
 777         }
 778         else
 779                 TraversingVisitor::visit(binary);
 780 }
 781
 782 void ProgramCompiler::UnusedVariableLocator::visit(ExpressionStatement &expr)
 783 {
 784         assignment = false;
 785         assignment_target = 0;
 786         indeterminate_target = false;
 787         self_referencing = false;
 788         TraversingVisitor::visit(expr);
 789         if(assignment && assignment_target && !indeterminate_target)
 790         {
 791                 Node *&assign = assignments[assignment_target];
 792                 if(self_referencing)
 793                         unused_nodes.erase(assign);
 794                 else if(assign)
 795                         unused_nodes.insert(assign);
 796                 assign = &expr;
 797                 if(assignment_target->interface=="out" && (stage->type==FRAGMENT || assignment_target->linked_declaration))
 798                         unused_nodes.erase(assignment_target);
 799                 else
 800                         unused_nodes.insert(&expr);
 801         }
 802         assignment = false;
 803 }
 804
 805 void ProgramCompiler::UnusedVariableLocator::visit(StructDeclaration &strct)
 806 {
 807         SetForScope<Node *> set(aggregate, &strct);
 808         unused_nodes.insert(&strct);
 809         TraversingVisitor::visit(strct);
 810 }
 811
 812 void ProgramCompiler::UnusedVariableLocator::visit(VariableDeclaration &var)
 813 {
 814         if(aggregate)
 815                 aggregates[&var] = aggregate;
 816         else
 817         {
 818                 unused_nodes.insert(&var);
 819                 if(var.init_expression)
 820                 {
 821                         unused_nodes.insert(&*var.init_expression);
 822                         assignments[&var] = &*var.init_expression;
 823                 }
 824         }
 825         unused_nodes.erase(var.type_declaration);
 826         TraversingVisitor::visit(var);
 827 }
 828
 829 void ProgramCompiler::UnusedVariableLocator::visit(InterfaceBlock &iface)
 830 {
 831         SetForScope<Node *> set(aggregate, &iface);
 832         unused_nodes.insert(&iface);
 833         TraversingVisitor::visit(iface);
 834 }
 835
 836
 837 void ProgramCompiler::NodeRemover::visit(Block &block)
 838 {
 839         for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
 840         {
 841                 (*i)->visit(*this);
 842                 if(to_remove.count(&**i))
 843                         block.body.erase(i++);
 844                 else
 845                         ++i;
 846         }
 847 }
 848
 849 void ProgramCompiler::NodeRemover::visit(VariableDeclaration &var)
 850 {
 851         if(to_remove.count(&var))
 852         {
 853                 stage->in_variables.erase(var.name);
 854                 stage->out_variables.erase(var.name);
 855                 if(var.linked_declaration)
 856                         var.linked_declaration->linked_declaration = 0;
 857         }
 858         else if(var.init_expression && to_remove.count(&*var.init_expression))
 859                 var.init_expression = 0;
 860 }
 861
 862 } // namespace GL
 863 } // namespace Msp