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(0)
 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         formatted += binary.oper;
 213         binary.right->visit(*this);
 214         formatted += binary.after;
 215 }
 216
 217 void ProgramCompiler::Formatter::visit(Assignment &assign)
 218 {
 219         assign.left->visit(*this);
 220         formatted += format(" %s ", assign.oper);
 221         assign.right->visit(*this);
 222 }
 223
 224 void ProgramCompiler::Formatter::visit(FunctionCall &call)
 225 {
 226         formatted += format("%s(", call.name);
 227         for(vector<NodePtr<Expression> >::iterator i=call.arguments.begin(); i!=call.arguments.end(); ++i)
 228         {
 229                 if(i!=call.arguments.begin())
 230                         formatted += ", ";
 231                 (*i)->visit(*this);
 232         }
 233         formatted += ')';
 234 }
 235
 236 void ProgramCompiler::Formatter::visit(ExpressionStatement &expr)
 237 {
 238         expr.expression->visit(*this);
 239         formatted += ';';
 240 }
 241
 242 void ProgramCompiler::Formatter::visit(Block &block)
 243 {
 244         if(else_if)
 245                 --else_if;
 246
 247         unsigned brace_indent = indent;
 248         if(block.use_braces)
 249                 formatted += format("%s{\n", string(brace_indent*2, ' '));
 250
 251         SetForScope<unsigned> set(indent, indent+!formatted.empty());
 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                 formatted += spaces;
 258                 (*i)->visit(*this);
 259                 else_if = 0;
 260         }
 261
 262         if(block.use_braces)
 263                 formatted += format("\n%s}", string(brace_indent*2, ' '));
 264 }
 265
 266 void ProgramCompiler::Formatter::visit(Layout &layout)
 267 {
 268         formatted += "layout(";
 269         for(vector<Layout::Qualifier>::const_iterator i=layout.qualifiers.begin(); i!=layout.qualifiers.end(); ++i)
 270         {
 271                 if(i!=layout.qualifiers.begin())
 272                         formatted += ", ";
 273                 formatted += i->identifier;
 274                 if(!i->value.empty())
 275                         formatted += format("=%s", i->value);
 276         }
 277         formatted += format(") %s;", layout.interface);
 278 }
 279
 280 void ProgramCompiler::Formatter::visit(StructDeclaration &strct)
 281 {
 282         formatted += format("struct %s\n", strct.name);
 283         strct.members.visit(*this);
 284         formatted += ';';
 285 }
 286
 287 void ProgramCompiler::Formatter::visit(VariableDeclaration &var)
 288 {
 289         if(var.constant)
 290                 formatted += "const ";
 291         if(!var.sampling.empty())
 292                 formatted += format("%s ", var.sampling);
 293         if(!var.interface.empty() && var.interface!=block_interface)
 294                 formatted += format("%s ", var.interface);
 295         formatted += format("%s %s", var.type, var.name);
 296         if(var.array)
 297         {
 298                 formatted += '[';
 299                 if(var.array_size)
 300                         var.array_size->visit(*this);
 301                 formatted += ']';
 302         }
 303         if(var.init_expression)
 304         {
 305                 formatted += " = ";
 306                 var.init_expression->visit(*this);
 307         }
 308         if(!parameter_list)
 309                 formatted += ';';
 310 }
 311
 312 void ProgramCompiler::Formatter::visit(InterfaceBlock &iface)
 313 {
 314         SetForScope<string> set(block_interface, iface.interface);
 315         formatted += format("%s %s\n", iface.interface, iface.name);
 316         iface.members.visit(*this);
 317         formatted += ';';
 318 }
 319
 320 void ProgramCompiler::Formatter::visit(FunctionDeclaration &func)
 321 {
 322         formatted += format("%s %s(", func.return_type, func.name);
 323         for(vector<NodePtr<VariableDeclaration> >::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
 324         {
 325                 if(i!=func.parameters.begin())
 326                         formatted += ", ";
 327                 SetFlag set(parameter_list);
 328                 (*i)->visit(*this);
 329         }
 330         formatted += ')';
 331         if(func.definition)
 332         {
 333                 formatted += '\n';
 334                 func.body.visit(*this);
 335         }
 336         else
 337                 formatted += ';';
 338 }
 339
 340 void ProgramCompiler::Formatter::visit(Conditional &cond)
 341 {
 342         if(else_if)
 343                 formatted.replace(formatted.rfind('\n'), string::npos, 1, ' ');
 344
 345         indent -= else_if;
 346
 347         formatted += "if(";
 348         cond.condition->visit(*this);
 349         formatted += ")\n";
 350
 351         cond.body.visit(*this);
 352         if(!cond.else_body.body.empty())
 353         {
 354                 formatted += format("\n%selse\n", string(indent*2, ' '));
 355                 SetForScope<unsigned> set(else_if, 2);
 356                 cond.else_body.visit(*this);
 357         }
 358 }
 359
 360 void ProgramCompiler::Formatter::visit(Iteration &iter)
 361 {
 362         formatted += "for(";
 363         iter.init_statement->visit(*this);
 364         formatted += ' ';
 365         iter.condition->visit(*this);
 366         formatted += "; ";
 367         iter.loop_expression->visit(*this);
 368         formatted += ")\n";
 369         iter.body.visit(*this);
 370 }
 371
 372 void ProgramCompiler::Formatter::visit(Return &ret)
 373 {
 374         formatted += "return ";
 375         ret.expression->visit(*this);
 376         formatted += ';';
 377 }
 378
 379
 380 ProgramCompiler::VariableResolver::VariableResolver():
 381         anonymous(false),
 382         record_target(false),
 383         assignment_target(0),
 384         self_referencing(false)
 385 { }
 386
 387 void ProgramCompiler::VariableResolver::apply(Stage &s)
 388 {
 389         SetForScope<Stage *> set(stage, &s);
 390         Stage *builtins = get_builtins(stage->type);
 391         if(builtins)
 392                 blocks.push_back(&builtins->content);
 393         stage->content.visit(*this);
 394         if(builtins)
 395                 blocks.pop_back();
 396 }
 397
 398 void ProgramCompiler::VariableResolver::visit(Block &block)
 399 {
 400         blocks.push_back(&block);
 401         block.variables.clear();
 402         TraversingVisitor::visit(block);
 403         blocks.pop_back();
 404 }
 405
 406 void ProgramCompiler::VariableResolver::visit(VariableReference &var)
 407 {
 408         var.declaration = 0;
 409         type = 0;
 410         for(vector<Block *>::iterator i=blocks.end(); i!=blocks.begin(); )
 411         {
 412                 --i;
 413                 map<string, VariableDeclaration *>::iterator j = (*i)->variables.find(var.name);
 414                 if(j!=(*i)->variables.end())
 415                 {
 416                         var.declaration = j->second;
 417                         type = j->second->type_declaration;
 418                         break;
 419                 }
 420         }
 421
 422         if(record_target)
 423         {
 424                 if(assignment_target)
 425                 {
 426                         record_target = false;
 427                         assignment_target = 0;
 428                 }
 429                 else
 430                         assignment_target = var.declaration;
 431         }
 432         else if(var.declaration && var.declaration==assignment_target)
 433                 self_referencing = true;
 434 }
 435
 436 void ProgramCompiler::VariableResolver::visit(MemberAccess &memacc)
 437 {
 438         type = 0;
 439         TraversingVisitor::visit(memacc);
 440         memacc.declaration = 0;
 441         if(type)
 442         {
 443                 map<string, VariableDeclaration *>::iterator i = type->members.variables.find(memacc.member);
 444                 if(i!=type->members.variables.end())
 445                 {
 446                         memacc.declaration = i->second;
 447                         type = i->second->type_declaration;
 448                 }
 449                 else
 450                         type = 0;
 451         }
 452 }
 453
 454 void ProgramCompiler::VariableResolver::visit(BinaryExpression &binary)
 455 {
 456         if(binary.oper=="[")
 457         {
 458                 {
 459                         SetForScope<bool> set(record_target, false);
 460                         binary.right->visit(*this);
 461                 }
 462                 type = 0;
 463                 binary.left->visit(*this);
 464         }
 465         else
 466         {
 467                 TraversingVisitor::visit(binary);
 468                 type = 0;
 469         }
 470 }
 471
 472 void ProgramCompiler::VariableResolver::visit(Assignment &assign)
 473 {
 474         {
 475                 SetFlag set(record_target);
 476                 assignment_target = 0;
 477                 assign.left->visit(*this);
 478         }
 479
 480         self_referencing = false;
 481         assign.right->visit(*this);
 482
 483         assign.self_referencing = (self_referencing || assign.oper!="=");
 484         assign.target_declaration = assignment_target;
 485 }
 486
 487 void ProgramCompiler::VariableResolver::visit(StructDeclaration &strct)
 488 {
 489         TraversingVisitor::visit(strct);
 490         blocks.back()->types[strct.name] = &strct;
 491 }
 492
 493 void ProgramCompiler::VariableResolver::visit(VariableDeclaration &var)
 494 {
 495         for(vector<Block *>::iterator i=blocks.end(); i!=blocks.begin(); )
 496         {
 497                 --i;
 498                 map<string, StructDeclaration *>::iterator j = (*i)->types.find(var.type);
 499                 if(j!=(*i)->types.end())
 500                         var.type_declaration = j->second;
 501         }
 502
 503         if(!block_interface.empty() && var.interface.empty())
 504                 var.interface = block_interface;
 505
 506         TraversingVisitor::visit(var);
 507         blocks.back()->variables[var.name] = &var;
 508         if(anonymous && blocks.size()>1)
 509                 blocks[blocks.size()-2]->variables[var.name] = &var;
 510 }
 511
 512 void ProgramCompiler::VariableResolver::visit(InterfaceBlock &iface)
 513 {
 514         SetFlag set(anonymous);
 515         SetForScope<string> set2(block_interface, iface.interface);
 516         TraversingVisitor::visit(iface);
 517 }
 518
 519
 520 ProgramCompiler::InterfaceGenerator::InterfaceGenerator():
 521         scope_level(0),
 522         remove_node(false)
 523 { }
 524
 525 string ProgramCompiler::InterfaceGenerator::get_out_prefix(StageType type)
 526 {
 527         if(type==VERTEX)
 528                 return "_vs_out_";
 529         else if(type==GEOMETRY)
 530                 return "_gs_out_";
 531         else
 532                 return string();
 533 }
 534
 535 void ProgramCompiler::InterfaceGenerator::apply(Stage &s)
 536 {
 537         SetForScope<Stage *> set(stage, &s);
 538         if(stage->previous)
 539                 in_prefix = get_out_prefix(stage->previous->type);
 540         out_prefix = get_out_prefix(stage->type);
 541         stage->content.visit(*this);
 542 }
 543
 544 void ProgramCompiler::InterfaceGenerator::visit(Block &block)
 545 {
 546         SetForScope<unsigned> set(scope_level, scope_level+1);
 547         for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
 548         {
 549                 (*i)->visit(*this);
 550
 551                 if(scope_level==1)
 552                 {
 553                         for(map<string, VariableDeclaration *>::iterator j=iface_declarations.begin(); j!=iface_declarations.end(); ++j)
 554                         {
 555                                 list<NodePtr<Node> >::iterator k = block.body.insert(i, j->second);
 556                                 (*k)->visit(*this);
 557                         }
 558                         iface_declarations.clear();
 559                 }
 560
 561                 for(list<Node *>::iterator j=insert_nodes.begin(); j!=insert_nodes.end(); ++j)
 562                         block.body.insert(i, *j);
 563                 insert_nodes.clear();
 564
 565                 if(remove_node)
 566                         block.body.erase(i++);
 567                 else
 568                         ++i;
 569                 remove_node = false;
 570         }
 571 }
 572
 573 string ProgramCompiler::InterfaceGenerator::change_prefix(const string &name, const string &prefix) const
 574 {
 575         unsigned offset = (name.compare(0, in_prefix.size(), in_prefix) ? 0 : in_prefix.size());
 576         return prefix+name.substr(offset);
 577 }
 578
 579 bool ProgramCompiler::InterfaceGenerator::generate_interface(VariableDeclaration &var, const string &iface, const string &name)
 580 {
 581         const map<string, VariableDeclaration *> &stage_vars = (iface=="in" ? stage->in_variables : stage->out_variables);
 582         if(stage_vars.count(name) || iface_declarations.count(name))
 583                 return false;
 584
 585         VariableDeclaration* iface_var = new VariableDeclaration;
 586         iface_var->sampling = var.sampling;
 587         iface_var->interface = iface;
 588         iface_var->type = var.type;
 589         iface_var->type_declaration = var.type_declaration;
 590         iface_var->name = name;
 591         if(stage->type==GEOMETRY)
 592                 iface_var->array = ((var.array && var.interface!="in") || iface=="in");
 593         else
 594                 iface_var->array = var.array;
 595         if(iface_var->array)
 596                 iface_var->array_size = var.array_size;
 597         if(iface=="in")
 598                 iface_var->linked_declaration = &var;
 599         iface_declarations[name] = iface_var;
 600
 601         return true;
 602 }
 603
 604 void ProgramCompiler::InterfaceGenerator::insert_assignment(const string &left, ProgramSyntax::Expression *right)
 605 {
 606         Assignment *assign = new Assignment;
 607         VariableReference *ref = new VariableReference;
 608         ref->name = left;
 609         assign->left = ref;
 610         assign->oper = "=";
 611         assign->right = right;
 612
 613         ExpressionStatement *stmt = new ExpressionStatement;
 614         stmt->expression = assign;
 615         insert_nodes.push_back(stmt);
 616 }
 617
 618 void ProgramCompiler::InterfaceGenerator::visit(VariableReference &var)
 619 {
 620         if(var.declaration || !stage->previous)
 621                 return;
 622         if(iface_declarations.count(var.name))
 623                 return;
 624
 625         const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
 626         map<string, VariableDeclaration *>::const_iterator i = prev_out.find(var.name);
 627         if(i==prev_out.end())
 628                 i = prev_out.find(in_prefix+var.name);
 629         if(i!=prev_out.end())
 630                 generate_interface(*i->second, "in", var.name);
 631 }
 632
 633 void ProgramCompiler::InterfaceGenerator::visit(VariableDeclaration &var)
 634 {
 635         if(var.interface=="out")
 636         {
 637                 if(scope_level==1)
 638                         stage->out_variables[var.name] = &var;
 639                 else if(generate_interface(var, "out", change_prefix(var.name, string())))
 640                 {
 641                         remove_node = true;
 642                         if(var.init_expression)
 643                                 insert_assignment(var.name, var.init_expression->clone());
 644                 }
 645         }
 646         else if(var.interface=="in")
 647         {
 648                 stage->in_variables[var.name] = &var;
 649                 if(var.linked_declaration)
 650                         var.linked_declaration->linked_declaration = &var;
 651                 else if(stage->previous)
 652                 {
 653                         const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
 654                         map<string, VariableDeclaration *>::const_iterator i = prev_out.find(var.name);
 655                         if(i!=prev_out.end())
 656                         {
 657                                 var.linked_declaration = i->second;
 658                                 i->second->linked_declaration = &var;
 659                         }
 660                 }
 661         }
 662
 663         TraversingVisitor::visit(var);
 664 }
 665
 666 void ProgramCompiler::InterfaceGenerator::visit(Passthrough &pass)
 667 {
 668         vector<VariableDeclaration *> pass_vars;
 669
 670         for(map<string, VariableDeclaration *>::const_iterator i=stage->in_variables.begin(); i!=stage->in_variables.end(); ++i)
 671                 pass_vars.push_back(i->second);
 672         for(map<string, VariableDeclaration *>::const_iterator i=iface_declarations.begin(); i!=iface_declarations.end(); ++i)
 673                 if(i->second->interface=="in")
 674                         pass_vars.push_back(i->second);
 675
 676         if(stage->previous)
 677         {
 678                 const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
 679                 for(map<string, VariableDeclaration *>::const_iterator i=prev_out.begin(); i!=prev_out.end(); ++i)
 680                 {
 681                         bool linked = false;
 682                         for(vector<VariableDeclaration *>::const_iterator j=pass_vars.begin(); (!linked && j!=pass_vars.end()); ++j)
 683                                 linked = ((*j)->linked_declaration==i->second);
 684
 685                         if(!linked && generate_interface(*i->second, "in", i->second->name))
 686                                 pass_vars.push_back(i->second);
 687                 }
 688         }
 689
 690         if(stage->type==GEOMETRY)
 691         {
 692                 VariableReference *ref = new VariableReference;
 693                 ref->name = "gl_in";
 694
 695                 BinaryExpression *subscript = new BinaryExpression;
 696                 subscript->left = ref;
 697                 subscript->oper = "[";
 698                 subscript->right = pass.subscript;
 699                 subscript->after = "]";
 700
 701                 MemberAccess *memacc = new MemberAccess;
 702                 memacc->left = subscript;
 703                 memacc->member = "gl_Position";
 704
 705                 insert_assignment("gl_Position", memacc);
 706         }
 707
 708         for(vector<VariableDeclaration *>::const_iterator i=pass_vars.begin(); i!=pass_vars.end(); ++i)
 709         {
 710                 string out_name = change_prefix((*i)->name, out_prefix);
 711                 generate_interface(**i, "out", out_name);
 712
 713                 VariableReference *ref = new VariableReference;
 714                 ref->name = (*i)->name;
 715                 if(pass.subscript)
 716                 {
 717                         BinaryExpression *subscript = new BinaryExpression;
 718                         subscript->left = ref;
 719                         subscript->oper = "[";
 720                         subscript->right = pass.subscript;
 721                         subscript->after = "]";
 722                         insert_assignment(out_name, subscript);
 723                 }
 724                 else
 725                         insert_assignment(out_name, ref);
 726         }
 727
 728         remove_node = true;
 729 }
 730
 731
 732 void ProgramCompiler::VariableRenamer::visit(VariableReference &var)
 733 {
 734         if(var.declaration)
 735                 var.name = var.declaration->name;
 736 }
 737
 738 void ProgramCompiler::VariableRenamer::visit(VariableDeclaration &var)
 739 {
 740         if(var.linked_declaration)
 741                 var.name = var.linked_declaration->name;
 742         TraversingVisitor::visit(var);
 743 }
 744
 745
 746 ProgramCompiler::UnusedVariableLocator::UnusedVariableLocator():
 747         aggregate(0),
 748         assignment(0),
 749         assignment_target(false)
 750 { }
 751
 752 void ProgramCompiler::UnusedVariableLocator::apply(Stage &s)
 753 {
 754         assignments.push_back(BlockAssignmentMap());
 755         Visitor::apply(s);
 756         assignments.pop_back();
 757 }
 758
 759 void ProgramCompiler::UnusedVariableLocator::visit(VariableReference &var)
 760 {
 761         unused_nodes.erase(var.declaration);
 762
 763         map<VariableDeclaration *, Node *>::iterator i = aggregates.find(var.declaration);
 764         if(i!=aggregates.end())
 765                 unused_nodes.erase(i->second);
 766
 767         if(assignment_target)
 768                 return;
 769
 770         for(vector<BlockAssignmentMap>::iterator j=assignments.end(); j!=assignments.begin(); )
 771         {
 772                 --j;
 773                 BlockAssignmentMap::iterator k = j->find(var.declaration);
 774                 if(k!=j->end())
 775                 {
 776                         for(vector<Node *>::iterator l=k->second.nodes.begin(); l!=k->second.nodes.end(); ++l)
 777                                 unused_nodes.erase(*l);
 778                         j->erase(k);
 779                         break;
 780                 }
 781         }
 782 }
 783
 784 void ProgramCompiler::UnusedVariableLocator::visit(MemberAccess &memacc)
 785 {
 786         TraversingVisitor::visit(memacc);
 787         unused_nodes.erase(memacc.declaration);
 788 }
 789
 790 void ProgramCompiler::UnusedVariableLocator::visit(BinaryExpression &binary)
 791 {
 792         if(binary.oper=="[")
 793         {
 794                 binary.left->visit(*this);
 795                 SetForScope<bool> set(assignment_target, false);
 796                 binary.right->visit(*this);
 797         }
 798         else
 799                 TraversingVisitor::visit(binary);
 800 }
 801
 802 void ProgramCompiler::UnusedVariableLocator::visit(Assignment &assign)
 803 {
 804         {
 805                 SetForScope<bool> set(assignment_target, !assign.self_referencing);
 806                 assign.left->visit(*this);
 807         }
 808         assign.right->visit(*this);
 809         assignment = &assign;
 810 }
 811
 812 void ProgramCompiler::UnusedVariableLocator::record_assignment(VariableDeclaration &var, Node &node, bool self_ref)
 813 {
 814         unused_nodes.insert(&node);
 815         BlockAssignmentMap &block_assignments = assignments.back();
 816         AssignmentList &var_assignments = block_assignments[&var];
 817         if(!self_ref)
 818                 var_assignments.nodes.clear();
 819         var_assignments.nodes.push_back(&node);
 820         var_assignments.conditional = false;
 821         var_assignments.self_referencing = self_ref;
 822 }
 823
 824 void ProgramCompiler::UnusedVariableLocator::visit(ExpressionStatement &expr)
 825 {
 826         assignment = 0;
 827         TraversingVisitor::visit(expr);
 828         if(assignment && assignment->target_declaration)
 829                 record_assignment(*assignment->target_declaration, expr, assignment->self_referencing);
 830 }
 831
 832 void ProgramCompiler::UnusedVariableLocator::visit(StructDeclaration &strct)
 833 {
 834         SetForScope<Node *> set(aggregate, &strct);
 835         unused_nodes.insert(&strct);
 836         TraversingVisitor::visit(strct);
 837 }
 838
 839 void ProgramCompiler::UnusedVariableLocator::visit(VariableDeclaration &var)
 840 {
 841         if(aggregate)
 842                 aggregates[&var] = aggregate;
 843         else
 844         {
 845                 unused_nodes.insert(&var);
 846                 if(var.init_expression)
 847                         record_assignment(var, *var.init_expression, false);
 848         }
 849         unused_nodes.erase(var.type_declaration);
 850         TraversingVisitor::visit(var);
 851 }
 852
 853 void ProgramCompiler::UnusedVariableLocator::visit(InterfaceBlock &iface)
 854 {
 855         SetForScope<Node *> set(aggregate, &iface);
 856         unused_nodes.insert(&iface);
 857         TraversingVisitor::visit(iface);
 858 }
 859
 860 void ProgramCompiler::UnusedVariableLocator::visit(FunctionDeclaration &func)
 861 {
 862         assignments.push_back(BlockAssignmentMap());
 863
 864         for(vector<NodePtr<VariableDeclaration> >::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
 865                 (*i)->visit(*this);
 866         func.body.visit(*this);
 867
 868         BlockAssignmentMap &block_assignments = assignments.back();
 869         for(map<string, VariableDeclaration *>::iterator i=func.body.variables.begin(); i!=func.body.variables.end(); ++i)
 870                 block_assignments.erase(i->second);
 871         for(BlockAssignmentMap::iterator i=block_assignments.begin(); i!=block_assignments.end(); ++i)
 872         {
 873                 if(i->first->interface=="out" && stage->type!=FRAGMENT && !i->first->linked_declaration)
 874                         continue;
 875
 876                 for(vector<Node *>::iterator j=i->second.nodes.begin(); j!=i->second.nodes.end(); ++j)
 877                         unused_nodes.erase(*j);
 878         }
 879
 880         assignments.pop_back();
 881 }
 882
 883 void ProgramCompiler::UnusedVariableLocator::merge_down_assignments()
 884 {
 885         BlockAssignmentMap &parent_assignments = assignments[assignments.size()-2];
 886         BlockAssignmentMap &block_assignments = assignments.back();
 887         for(BlockAssignmentMap::iterator i=block_assignments.begin(); i!=block_assignments.end(); ++i)
 888         {
 889                 BlockAssignmentMap::iterator j = parent_assignments.find(i->first);
 890                 if(j==parent_assignments.end())
 891                         parent_assignments.insert(*i);
 892                 else if(i->second.self_referencing || i->second.conditional)
 893                 {
 894                         j->second.nodes.insert(j->second.nodes.end(), i->second.nodes.begin(), i->second.nodes.end());
 895                         j->second.conditional |= i->second.conditional;
 896                         j->second.self_referencing |= i->second.self_referencing;
 897                 }
 898                 else
 899                         j->second = i->second;
 900         }
 901         assignments.pop_back();
 902 }
 903
 904 void ProgramCompiler::UnusedVariableLocator::visit(Conditional &cond)
 905 {
 906         cond.condition->visit(*this);
 907         assignments.push_back(BlockAssignmentMap());
 908         cond.body.visit(*this);
 909
 910         BlockAssignmentMap if_assignments;
 911         swap(assignments.back(), if_assignments);
 912         cond.else_body.visit(*this);
 913
 914         BlockAssignmentMap &else_assignments = assignments.back();
 915         for(BlockAssignmentMap::iterator i=else_assignments.begin(); i!=else_assignments.end(); ++i)
 916         {
 917                 BlockAssignmentMap::iterator j = if_assignments.find(i->first);
 918                 if(j!=if_assignments.end())
 919                 {
 920                         i->second.nodes.insert(i->second.nodes.end(), j->second.nodes.begin(), j->second.nodes.end());
 921                         i->second.conditional |= j->second.conditional;
 922                         i->second.self_referencing |= j->second.self_referencing;
 923                         if_assignments.erase(j);
 924                 }
 925                 else
 926                         i->second.conditional = true;
 927         }
 928
 929         for(BlockAssignmentMap::iterator i=if_assignments.begin(); i!=if_assignments.end(); ++i)
 930         {
 931                 i->second.conditional = true;
 932                 else_assignments.insert(*i);
 933         }
 934
 935         merge_down_assignments();
 936 }
 937
 938 void ProgramCompiler::UnusedVariableLocator::visit(Iteration &iter)
 939 {
 940         assignments.push_back(BlockAssignmentMap());
 941         TraversingVisitor::visit(iter);
 942         merge_down_assignments();
 943 }
 944
 945
 946 void ProgramCompiler::NodeRemover::visit(Block &block)
 947 {
 948         for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
 949         {
 950                 (*i)->visit(*this);
 951                 if(to_remove.count(&**i))
 952                         block.body.erase(i++);
 953                 else
 954                         ++i;
 955         }
 956 }
 957
 958 void ProgramCompiler::NodeRemover::visit(VariableDeclaration &var)
 959 {
 960         if(to_remove.count(&var))
 961         {
 962                 stage->in_variables.erase(var.name);
 963                 stage->out_variables.erase(var.name);
 964                 if(var.linked_declaration)
 965                         var.linked_declaration->linked_declaration = 0;
 966         }
 967         else if(var.init_expression && to_remove.count(&*var.init_expression))
 968                 var.init_expression = 0;
 969 }
 970
 971 } // namespace GL
 972 } // namespace Msp