source/glsl/generate.cpp

   1 #include <msp/core/hash.h>
   2 #include <msp/core/raii.h>
   3 #include <msp/strings/lexicalcast.h>
   4 #include "builtin.h"
   5 #include "generate.h"
   6
   7 using namespace std;
   8
   9 namespace Msp {
  10 namespace GL {
  11 namespace SL {
  12
  13 void DeclarationCombiner::apply(Stage &stage)
  14 {
  15         stage.content.visit(*this);
  16         NodeRemover().apply(stage, nodes_to_remove);
  17 }
  18
  19 void DeclarationCombiner::visit(Block &block)
  20 {
  21         if(current_block)
  22                 return;
  23
  24         TraversingVisitor::visit(block);
  25 }
  26
  27 void DeclarationCombiner::visit(VariableDeclaration &var)
  28 {
  29         VariableDeclaration *&ptr = variables[var.name];
  30         if(ptr)
  31         {
  32                 ptr->type = var.type;
  33                 if(var.init_expression)
  34                         ptr->init_expression = var.init_expression;
  35                 if(var.layout)
  36                 {
  37                         if(ptr->layout)
  38                         {
  39                                 for(vector<Layout::Qualifier>::iterator i=var.layout->qualifiers.begin(); i!=var.layout->qualifiers.end(); ++i)
  40                                 {
  41                                         bool found = false;
  42                                         for(vector<Layout::Qualifier>::iterator j=ptr->layout->qualifiers.begin(); (!found && j!=ptr->layout->qualifiers.end()); ++j)
  43                                                 if(j->name==i->name)
  44                                                 {
  45                                                         j->has_value = i->value;
  46                                                         j->value = i->value;
  47                                                         found = true;
  48                                                 }
  49
  50                                         if(!found)
  51                                                 ptr->layout->qualifiers.push_back(*i);
  52                                 }
  53                         }
  54                         else
  55                                 ptr->layout = var.layout;
  56                 }
  57                 nodes_to_remove.insert(&var);
  58         }
  59         else
  60                 ptr = &var;
  61 }
  62
  63
  64 ConstantSpecializer::ConstantSpecializer():
  65         values(0)
  66 { }
  67
  68 void ConstantSpecializer::apply(Stage &stage, const map<string, int> *v)
  69 {
  70         values = v;
  71         stage.content.visit(*this);
  72 }
  73
  74 void ConstantSpecializer::visit(VariableDeclaration &var)
  75 {
  76         bool specializable = false;
  77         if(var.layout)
  78         {
  79                 vector<Layout::Qualifier> &qualifiers = var.layout->qualifiers;
  80                 for(vector<Layout::Qualifier>::iterator i=qualifiers.begin(); i!=qualifiers.end(); ++i)
  81                         if(i->name=="constant_id")
  82                         {
  83                                 specializable = true;
  84                                 if(values)
  85                                         qualifiers.erase(i);
  86                                 else if(i->value==-1)
  87                                         i->value = hash32(var.name)&0x7FFFFFFF;
  88                                 break;
  89                         }
  90
  91                 if(qualifiers.empty())
  92                         var.layout = 0;
  93         }
  94
  95         if(specializable && values)
  96         {
  97                 map<string, int>::const_iterator i = values->find(var.name);
  98                 if(i!=values->end())
  99                 {
 100                         RefPtr<Literal> literal = new Literal;
 101                         if(var.type=="bool")
 102                         {
 103                                 literal->token = (i->second ? "true" : "false");
 104                                 literal->value = static_cast<bool>(i->second);
 105                         }
 106                         else if(var.type=="int")
 107                         {
 108                                 literal->token = lexical_cast<string>(i->second);
 109                                 literal->value = i->second;
 110                         }
 111                         var.init_expression = literal;
 112                 }
 113         }
 114 }
 115
 116
 117 void BlockHierarchyResolver::enter(Block &block)
 118 {
 119         block.parent = current_block;
 120 }
 121
 122
 123 TypeResolver::TypeResolver():
 124         stage(0)
 125 { }
 126
 127 void TypeResolver::apply(Stage &s)
 128 {
 129         stage = &s;
 130         s.types.clear();
 131         s.content.visit(*this);
 132 }
 133
 134 TypeDeclaration *TypeResolver::resolve_type(const string &name)
 135 {
 136         map<string, TypeDeclaration *>::iterator i = stage->types.find(name);
 137         if(i!=stage->types.end())
 138         {
 139                 map<TypeDeclaration *, TypeDeclaration *>::iterator j = alias_map.find(i->second);
 140                 return (j!=alias_map.end() ? j->second : i->second);
 141         }
 142         else
 143                 return 0;
 144 }
 145
 146 void TypeResolver::visit(Block &block)
 147 {
 148         for(NodeList<Statement>::iterator i=block.body.begin(); i!=block.body.end(); ++i)
 149         {
 150                 if(!block.parent)
 151                         type_insert_point = i;
 152                 (*i)->visit(*this);
 153         }
 154 }
 155
 156 void TypeResolver::visit(BasicTypeDeclaration &type)
 157 {
 158         type.base_type = resolve_type(type.base);
 159
 160         if(type.kind==BasicTypeDeclaration::VECTOR && type.base_type)
 161                 if(BasicTypeDeclaration *basic_base = dynamic_cast<BasicTypeDeclaration *>(type.base_type))
 162                         if(basic_base->kind==BasicTypeDeclaration::VECTOR)
 163                         {
 164                                 type.kind = BasicTypeDeclaration::MATRIX;
 165                                 type.size |= basic_base->size<<16;
 166                         }
 167
 168         if(type.kind==BasicTypeDeclaration::ALIAS && type.base_type)
 169                 alias_map[&type] = type.base_type;
 170         else if(type.kind==BasicTypeDeclaration::ARRAY && type.base_type)
 171                 array_types[type.base_type] = &type;
 172
 173         stage->types.insert(make_pair(type.name, &type));
 174 }
 175
 176 void TypeResolver::visit(ImageTypeDeclaration &type)
 177 {
 178         type.base_type = resolve_type(type.base);
 179         stage->types.insert(make_pair(type.name, &type));
 180 }
 181
 182 void TypeResolver::visit(StructDeclaration &strct)
 183 {
 184         stage->types.insert(make_pair(strct.name, &strct));
 185         TraversingVisitor::visit(strct);
 186 }
 187
 188 void TypeResolver::visit(VariableDeclaration &var)
 189 {
 190         TypeDeclaration *type = resolve_type(var.type);
 191         if(var.array && type)
 192         {
 193                 map<TypeDeclaration *, TypeDeclaration *>::iterator i = array_types.find(type);
 194                 if(i==array_types.end())
 195                 {
 196                         BasicTypeDeclaration *array = new BasicTypeDeclaration;
 197                         array->source = BUILTIN_SOURCE;
 198                         array->name = type->name+"[]";
 199                         array->kind = BasicTypeDeclaration::ARRAY;
 200                         array->base = type->name;
 201                         array->base_type = type;
 202                         stage->content.body.insert(type_insert_point, array);
 203                         array->visit(*this);
 204                         type = array;
 205                 }
 206                 else
 207                         type = i->second;
 208         }
 209         var.type_declaration = type;
 210 }
 211
 212 void TypeResolver::visit(FunctionDeclaration &func)
 213 {
 214         func.return_type_declaration = resolve_type(func.return_type);
 215         TraversingVisitor::visit(func);
 216 }
 217
 218
 219 VariableResolver::VariableResolver():
 220         stage(0),
 221         r_members(0),
 222         record_target(false),
 223         r_self_referencing(false),
 224         r_assignment_target(0)
 225 { }
 226
 227 void VariableResolver::apply(Stage &s)
 228 {
 229         stage = &s;
 230         s.interface_blocks.clear();
 231         s.content.visit(*this);
 232 }
 233
 234 void VariableResolver::enter(Block &block)
 235 {
 236         block.variables.clear();
 237 }
 238
 239 void VariableResolver::visit(VariableReference &var)
 240 {
 241         var.declaration = 0;
 242         r_members = 0;
 243         /* Look for variable declarations in the block hierarchy first.  Interface
 244         blocks are always defined in the top level so we can't accidentally skip
 245         one. */
 246         for(Block *block=current_block; (!var.declaration && block); block=block->parent)
 247         {
 248                 map<string, VariableDeclaration *>::iterator i = block->variables.find(var.name);
 249                 if(i!=block->variables.end())
 250                         var.declaration = i->second;
 251         }
 252
 253         if(!var.declaration)
 254         {
 255                 const map<string, InterfaceBlock *> &blocks = stage->interface_blocks;
 256                 map<string, InterfaceBlock *>::const_iterator i = blocks.find("_"+var.name);
 257                 if(i!=blocks.end())
 258                 {
 259                         /* The name refers to an interface block with an instance name rather
 260                         than a variable.  Prepare a new syntax tree node accordingly. */
 261                         r_iface_ref = new InterfaceBlockReference;
 262                         r_iface_ref->source = var.source;
 263                         r_iface_ref->line = var.line;
 264                         r_iface_ref->name = var.name;
 265                         r_iface_ref->declaration = i->second;
 266                         r_members = &i->second->members.variables;
 267                 }
 268                 else
 269                 {
 270                         // Look for the variable in anonymous interface blocks.
 271                         for(i=blocks.begin(); (!var.declaration && i!=blocks.end()); ++i)
 272                                 if(i->second->instance_name.empty())
 273                                 {
 274                                         map<string, VariableDeclaration *>::iterator j = i->second->members.variables.find(var.name);
 275                                         if(j!=i->second->members.variables.end())
 276                                                 var.declaration = j->second;
 277                                 }
 278                 }
 279         }
 280
 281         if(var.declaration)
 282                 if(StructDeclaration *strct = dynamic_cast<StructDeclaration *>(var.declaration->type_declaration))
 283                         r_members = &strct->members.variables;
 284
 285         if(record_target)
 286         {
 287                 if(r_assignment_target)
 288                 {
 289                         /* More than one variable reference found in assignment target.
 290                         Unable to determine what the primary target is. */
 291                         record_target = false;
 292                         r_assignment_target = 0;
 293                 }
 294                 else
 295                         r_assignment_target = var.declaration;
 296         }
 297         else if(var.declaration && var.declaration==r_assignment_target)
 298                 r_self_referencing = true;
 299 }
 300
 301 void VariableResolver::visit(InterfaceBlockReference &iface)
 302 {
 303         iface.declaration = 0;
 304         for(Block *block=current_block; block; block=block->parent)
 305         {
 306                 map<string, InterfaceBlock *>::iterator i = stage->interface_blocks.find("_"+iface.name);
 307                 if(i!=stage->interface_blocks.end())
 308                 {
 309                         iface.declaration = i->second;
 310                         r_members = &i->second->members.variables;
 311                         break;
 312                 }
 313         }
 314 }
 315
 316 void VariableResolver::visit(MemberAccess &memacc)
 317 {
 318         r_members = 0;
 319         r_iface_ref = 0;
 320         memacc.left->visit(*this);
 321
 322         if(r_iface_ref)
 323                 memacc.left = r_iface_ref;
 324         r_iface_ref = 0;
 325
 326         memacc.declaration = 0;
 327         if(r_members)
 328         {
 329                 map<string, VariableDeclaration *>::iterator i = r_members->find(memacc.member);
 330                 if(i!=r_members->end())
 331                 {
 332                         memacc.declaration = i->second;
 333                         if(StructDeclaration *strct = dynamic_cast<StructDeclaration *>(i->second->type_declaration))
 334                                 r_members = &strct->members.variables;
 335                 }
 336                 else
 337                         r_members = 0;
 338         }
 339 }
 340
 341 void VariableResolver::visit(UnaryExpression &unary)
 342 {
 343         TraversingVisitor::visit(unary);
 344         r_members = 0;
 345         r_iface_ref = 0;
 346 }
 347
 348 void VariableResolver::visit(BinaryExpression &binary)
 349 {
 350         if(binary.oper->token[0]=='[')
 351         {
 352                 {
 353                         /* The subscript expression is not a part of the primary assignment
 354                         target. */
 355                         SetFlag set(record_target, false);
 356                         binary.right->visit(*this);
 357                 }
 358                 r_members = 0;
 359                 r_iface_ref = 0;
 360                 binary.left->visit(*this);
 361                 if(r_iface_ref)
 362                         binary.left = r_iface_ref;
 363         }
 364         else
 365         {
 366                 TraversingVisitor::visit(binary);
 367                 r_members = 0;
 368         }
 369
 370         r_iface_ref = 0;
 371 }
 372
 373 void VariableResolver::visit(Assignment &assign)
 374 {
 375         {
 376                 SetFlag set(record_target);
 377                 r_assignment_target = 0;
 378                 assign.left->visit(*this);
 379                 assign.target_declaration = r_assignment_target;
 380         }
 381
 382         r_self_referencing = false;
 383         assign.right->visit(*this);
 384         assign.self_referencing = (r_self_referencing || assign.oper->token[0]!='=');
 385
 386         r_members = 0;
 387         r_iface_ref = 0;
 388 }
 389
 390 void VariableResolver::visit(FunctionCall &call)
 391 {
 392         TraversingVisitor::visit(call);
 393         r_members = 0;
 394         r_iface_ref = 0;
 395 }
 396
 397 void VariableResolver::visit(VariableDeclaration &var)
 398 {
 399         if(!block_interface.empty() && var.interface.empty())
 400                 var.interface = block_interface;
 401
 402         TraversingVisitor::visit(var);
 403         current_block->variables.insert(make_pair(var.name, &var));
 404 }
 405
 406 void VariableResolver::visit(InterfaceBlock &iface)
 407 {
 408         /* Block names can be reused in different interfaces.  Prefix the name with
 409         the first character of the interface to avoid conflicts. */
 410         stage->interface_blocks.insert(make_pair(iface.interface+iface.name, &iface));
 411         if(!iface.instance_name.empty())
 412                 stage->interface_blocks.insert(make_pair("_"+iface.instance_name, &iface));
 413
 414         SetForScope<string> set_iface(block_interface, iface.interface);
 415         TraversingVisitor::visit(iface);
 416 }
 417
 418
 419 void FunctionResolver::apply(Stage &s)
 420 {
 421         stage = &s;
 422         s.functions.clear();
 423         s.content.visit(*this);
 424 }
 425
 426 void FunctionResolver::visit(FunctionCall &call)
 427 {
 428         map<string, FunctionDeclaration *>::iterator i = stage->functions.find(call.name);
 429         if(i!=stage->functions.end())
 430                 call.declaration = i->second;
 431
 432         TraversingVisitor::visit(call);
 433 }
 434
 435 void FunctionResolver::visit(FunctionDeclaration &func)
 436 {
 437         FunctionDeclaration *&stage_decl = stage->functions[func.name];
 438         vector<FunctionDeclaration *> &decls = declarations[func.name];
 439         if(func.definition==&func)
 440         {
 441                 stage_decl = &func;
 442
 443                 // Set all previous declarations to use this definition.
 444                 for(vector<FunctionDeclaration *>::iterator i=decls.begin(); i!=decls.end(); ++i)
 445                 {
 446                         (*i)->definition = func.definition;
 447                         (*i)->body.body.clear();
 448                 }
 449         }
 450         else
 451         {
 452                 func.definition = 0;
 453                 if(!stage_decl)
 454                         stage_decl = &func;
 455                 else
 456                         func.definition = stage_decl->definition;
 457         }
 458         decls.push_back(&func);
 459
 460         TraversingVisitor::visit(func);
 461 }
 462
 463
 464 InterfaceGenerator::InterfaceGenerator():
 465         stage(0),
 466         function_scope(false),
 467         iface_block(0),
 468         copy_block(false),
 469         iface_target_block(0)
 470 { }
 471
 472 string InterfaceGenerator::get_out_prefix(Stage::Type type)
 473 {
 474         if(type==Stage::VERTEX)
 475                 return "_vs_out_";
 476         else if(type==Stage::GEOMETRY)
 477                 return "_gs_out_";
 478         else
 479                 return string();
 480 }
 481
 482 void InterfaceGenerator::apply(Stage &s)
 483 {
 484         stage = &s;
 485         iface_target_block = &stage->content;
 486         if(stage->previous)
 487                 in_prefix = get_out_prefix(stage->previous->type);
 488         out_prefix = get_out_prefix(stage->type);
 489         s.content.visit(*this);
 490         NodeRemover().apply(s, nodes_to_remove);
 491 }
 492
 493 void InterfaceGenerator::visit(Block &block)
 494 {
 495         SetForScope<Block *> set_block(current_block, &block);
 496         for(NodeList<Statement>::iterator i=block.body.begin(); i!=block.body.end(); ++i)
 497         {
 498                 assignment_insert_point = i;
 499                 if(&block==&stage->content)
 500                         iface_insert_point = i;
 501
 502                 (*i)->visit(*this);
 503         }
 504 }
 505
 506 string InterfaceGenerator::change_prefix(const string &name, const string &prefix) const
 507 {
 508         unsigned offset = (name.compare(0, in_prefix.size(), in_prefix) ? 0 : in_prefix.size());
 509         return prefix+name.substr(offset);
 510 }
 511
 512 VariableDeclaration *InterfaceGenerator::generate_interface(VariableDeclaration &var, const string &iface, const string &name)
 513 {
 514         if(stage->content.variables.count(name))
 515                 return 0;
 516
 517         VariableDeclaration* iface_var = new VariableDeclaration;
 518         iface_var->sampling = var.sampling;
 519         iface_var->interface = iface;
 520         iface_var->type = var.type;
 521         iface_var->name = name;
 522         /* Geometry shader inputs are always arrays.  But if we're bringing in an
 523         entire block, the array is on the block and not individual variables. */
 524         if(stage->type==Stage::GEOMETRY && !copy_block)
 525                 iface_var->array = ((var.array && var.interface!="in") || iface=="in");
 526         else
 527                 iface_var->array = var.array;
 528         if(iface_var->array)
 529                 iface_var->array_size = var.array_size;
 530         if(iface=="in")
 531         {
 532                 iface_var->layout = var.layout;
 533                 iface_var->linked_declaration = &var;
 534                 var.linked_declaration = iface_var;
 535         }
 536
 537         iface_target_block->body.insert(iface_insert_point, iface_var);
 538         iface_target_block->variables.insert(make_pair(name, iface_var));
 539
 540         return iface_var;
 541 }
 542
 543 InterfaceBlock *InterfaceGenerator::generate_interface(InterfaceBlock &out_block)
 544 {
 545         if(stage->interface_blocks.count("in"+out_block.name))
 546                 return 0;
 547
 548         InterfaceBlock *in_block = new InterfaceBlock;
 549         in_block->interface = "in";
 550         in_block->name = out_block.name;
 551         in_block->instance_name = out_block.instance_name;
 552         if(stage->type==Stage::GEOMETRY)
 553                 in_block->array = true;
 554         else
 555                 in_block->array = out_block.array;
 556         in_block->linked_block = &out_block;
 557         out_block.linked_block = in_block;
 558
 559         {
 560                 SetFlag set_copy(copy_block, true);
 561                 SetForScope<Block *> set_target(iface_target_block, &in_block->members);
 562                 SetForScope<NodeList<Statement>::iterator> set_ins_pt(iface_insert_point, in_block->members.body.end());
 563                 out_block.members.visit(*this);
 564         }
 565
 566         iface_target_block->body.insert(iface_insert_point, in_block);
 567         stage->interface_blocks.insert(make_pair("in"+in_block->name, in_block));
 568         if(!in_block->instance_name.empty())
 569                 stage->interface_blocks.insert(make_pair("_"+in_block->instance_name, in_block));
 570
 571         SetFlag set_scope(function_scope, false);
 572         SetForScope<Block *> set_block(current_block, &stage->content);
 573         in_block->visit(*this);
 574
 575         return in_block;
 576 }
 577
 578 ExpressionStatement &InterfaceGenerator::insert_assignment(const string &left, Expression *right)
 579 {
 580         Assignment *assign = new Assignment;
 581         VariableReference *ref = new VariableReference;
 582         ref->name = left;
 583         assign->left = ref;
 584         assign->oper = &Operator::get_operator("=", Operator::BINARY);
 585         assign->right = right;
 586
 587         ExpressionStatement *stmt = new ExpressionStatement;
 588         stmt->expression = assign;
 589         current_block->body.insert(assignment_insert_point, stmt);
 590         stmt->visit(*this);
 591
 592         return *stmt;
 593 }
 594
 595 void InterfaceGenerator::visit(VariableReference &var)
 596 {
 597         if(var.declaration || !stage->previous)
 598                 return;
 599         /* Don't pull a variable from previous stage if we just generated an output
 600         interface in this stage */
 601         if(stage->content.variables.count(var.name))
 602                 return;
 603
 604         const map<string, VariableDeclaration *> &prev_vars = stage->previous->content.variables;
 605         map<string, VariableDeclaration *>::const_iterator i = prev_vars.find(var.name);
 606         if(i==prev_vars.end() || i->second->interface!="out")
 607                 i = prev_vars.find(in_prefix+var.name);
 608         if(i!=prev_vars.end() && i->second->interface=="out")
 609         {
 610                 generate_interface(*i->second, "in", i->second->name);
 611                 var.name = i->second->name;
 612                 return;
 613         }
 614
 615         const map<string, InterfaceBlock *> &prev_blocks = stage->previous->interface_blocks;
 616         map<string, InterfaceBlock *>::const_iterator j = prev_blocks.find("_"+var.name);
 617         if(j!=prev_blocks.end() && j->second->interface=="out")
 618         {
 619                 generate_interface(*j->second);
 620                 /* Let VariableResolver convert the variable reference into an interface
 621                 block reference. */
 622                 return;
 623         }
 624
 625         for(j=prev_blocks.begin(); j!=prev_blocks.end(); ++j)
 626                 if(j->second->instance_name.empty())
 627                 {
 628                         i = j->second->members.variables.find(var.name);
 629                         if(i!=j->second->members.variables.end())
 630                         {
 631                                 generate_interface(*j->second);
 632                                 return;
 633                         }
 634                 }
 635 }
 636
 637 void InterfaceGenerator::visit(VariableDeclaration &var)
 638 {
 639         if(copy_block)
 640         {
 641                 generate_interface(var, "in", var.name);
 642                 return;
 643         }
 644
 645         if(iface_block)
 646         {
 647                 if(iface_block->linked_block)
 648                 {
 649                         // Link all variables to their counterparts in the linked block.
 650                         const map<string, VariableDeclaration *> &linked_vars = iface_block->linked_block->members.variables;
 651                         map<string, VariableDeclaration *>::const_iterator i = linked_vars.find(var.name);
 652                         if(i!=linked_vars.end())
 653                         {
 654                                 var.linked_declaration = i->second;
 655                                 var.linked_declaration->linked_declaration = &var;
 656                         }
 657                 }
 658                 return;
 659         }
 660
 661         if(var.interface=="out")
 662         {
 663                 /* For output variables in function scope, generate a global interface
 664                 and replace the local declaration with an assignment. */
 665                 VariableDeclaration *out_var = 0;
 666                 if(function_scope && (out_var=generate_interface(var, "out", var.name)))
 667                 {
 668                         out_var->source = var.source;
 669                         out_var->line = var.line;
 670                         nodes_to_remove.insert(&var);
 671                         if(var.init_expression)
 672                         {
 673                                 ExpressionStatement &stmt = insert_assignment(var.name, var.init_expression->clone());
 674                                 stmt.source = var.source;
 675                                 stmt.line = var.line;
 676                                 return;
 677                         }
 678                 }
 679         }
 680         else if(var.interface=="in")
 681         {
 682                 /* Try to link input variables in global scope with output variables from
 683                 previous stage. */
 684                 if(current_block==&stage->content && !var.linked_declaration && stage->previous)
 685                 {
 686                         const map<string, VariableDeclaration *> &prev_vars = stage->previous->content.variables;
 687                         map<string, VariableDeclaration *>::const_iterator i = prev_vars.find(var.name);
 688                         if(i!=prev_vars.end() && i->second->interface=="out")
 689                         {
 690                                 var.linked_declaration = i->second;
 691                                 i->second->linked_declaration = &var;
 692                         }
 693                 }
 694         }
 695
 696         TraversingVisitor::visit(var);
 697 }
 698
 699 void InterfaceGenerator::visit(InterfaceBlock &iface)
 700 {
 701         if(iface.interface=="in")
 702         {
 703                 /* Try to link input blocks with output blocks sharing the same block
 704                 name from previous stage. */
 705                 if(!iface.linked_block && stage->previous)
 706                 {
 707                         const map<string, InterfaceBlock *> &prev_blocks = stage->previous->interface_blocks;
 708                         map<string, InterfaceBlock *>::const_iterator i = prev_blocks.find("out"+iface.name);
 709                         if(i!=prev_blocks.end())
 710                         {
 711                                 iface.linked_block = i->second;
 712                                 i->second->linked_block = &iface;
 713                         }
 714                 }
 715         }
 716
 717         SetForScope<InterfaceBlock *> set_iface(iface_block, &iface);
 718         TraversingVisitor::visit(iface);
 719 }
 720
 721 void InterfaceGenerator::visit(FunctionDeclaration &func)
 722 {
 723         SetFlag set_scope(function_scope, true);
 724         // Skip parameters because they're not useful here
 725         func.body.visit(*this);
 726 }
 727
 728 void InterfaceGenerator::visit(Passthrough &pass)
 729 {
 730         vector<VariableDeclaration *> pass_vars;
 731
 732         // Pass through all input variables of this stage.
 733         for(map<string, VariableDeclaration *>::const_iterator i=stage->content.variables.begin(); i!=stage->content.variables.end(); ++i)
 734                 if(i->second->interface=="in")
 735                         pass_vars.push_back(i->second);
 736
 737         if(stage->previous)
 738         {
 739                 const map<string, VariableDeclaration *> &prev_vars = stage->previous->content.variables;
 740                 for(map<string, VariableDeclaration *>::const_iterator i=prev_vars.begin(); i!=prev_vars.end(); ++i)
 741                 {
 742                         if(i->second->interface!="out")
 743                                 continue;
 744
 745                         /* Pass through output variables from the previous stage, but only
 746                         those which are not already linked to an input here. */
 747                         if(!i->second->linked_declaration && generate_interface(*i->second, "in", i->second->name))
 748                                 pass_vars.push_back(i->second);
 749                 }
 750         }
 751
 752         if(stage->type==Stage::GEOMETRY)
 753         {
 754                 /* Special case for geometry shader: copy gl_Position from input to
 755                 output. */
 756                 InterfaceBlockReference *ref = new InterfaceBlockReference;
 757                 ref->name = "gl_in";
 758
 759                 BinaryExpression *subscript = new BinaryExpression;
 760                 subscript->left = ref;
 761                 subscript->oper = &Operator::get_operator("[", Operator::BINARY);
 762                 subscript->right = pass.subscript;
 763
 764                 MemberAccess *memacc = new MemberAccess;
 765                 memacc->left = subscript;
 766                 memacc->member = "gl_Position";
 767
 768                 insert_assignment("gl_Position", memacc);
 769         }
 770
 771         for(vector<VariableDeclaration *>::const_iterator i=pass_vars.begin(); i!=pass_vars.end(); ++i)
 772         {
 773                 string out_name = change_prefix((*i)->name, out_prefix);
 774                 generate_interface(**i, "out", out_name);
 775
 776                 VariableReference *ref = new VariableReference;
 777                 ref->name = (*i)->name;
 778                 if(pass.subscript)
 779                 {
 780                         BinaryExpression *subscript = new BinaryExpression;
 781                         subscript->left = ref;
 782                         subscript->oper = &Operator::get_operator("[", Operator::BINARY);
 783                         subscript->right = pass.subscript;
 784                         insert_assignment(out_name, subscript);
 785                 }
 786                 else
 787                         insert_assignment(out_name, ref);
 788         }
 789
 790         nodes_to_remove.insert(&pass);
 791 }
 792
 793 } // namespace SL
 794 } // namespace GL
 795 } // namespace Msp