| /* |
| * Copyright 2016 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkSLIRGenerator.h" |
| |
| #include "limits.h" |
| |
| #include "ast/SkSLASTBoolLiteral.h" |
| #include "ast/SkSLASTFieldSuffix.h" |
| #include "ast/SkSLASTFloatLiteral.h" |
| #include "ast/SkSLASTIndexSuffix.h" |
| #include "ast/SkSLASTIntLiteral.h" |
| #include "ir/SkSLBinaryExpression.h" |
| #include "ir/SkSLBoolLiteral.h" |
| #include "ir/SkSLBreakStatement.h" |
| #include "ir/SkSLConstructor.h" |
| #include "ir/SkSLContinueStatement.h" |
| #include "ir/SkSLDiscardStatement.h" |
| #include "ir/SkSLDoStatement.h" |
| #include "ir/SkSLExpressionStatement.h" |
| #include "ir/SkSLField.h" |
| #include "ir/SkSLFieldAccess.h" |
| #include "ir/SkSLFloatLiteral.h" |
| #include "ir/SkSLForStatement.h" |
| #include "ir/SkSLFunctionCall.h" |
| #include "ir/SkSLFunctionDeclaration.h" |
| #include "ir/SkSLFunctionDefinition.h" |
| #include "ir/SkSLFunctionReference.h" |
| #include "ir/SkSLIfStatement.h" |
| #include "ir/SkSLIndexExpression.h" |
| #include "ir/SkSLInterfaceBlock.h" |
| #include "ir/SkSLIntLiteral.h" |
| #include "ir/SkSLLayout.h" |
| #include "ir/SkSLPostfixExpression.h" |
| #include "ir/SkSLPrefixExpression.h" |
| #include "ir/SkSLReturnStatement.h" |
| #include "ir/SkSLSwizzle.h" |
| #include "ir/SkSLTernaryExpression.h" |
| #include "ir/SkSLUnresolvedFunction.h" |
| #include "ir/SkSLVariable.h" |
| #include "ir/SkSLVarDeclaration.h" |
| #include "ir/SkSLVarDeclarationStatement.h" |
| #include "ir/SkSLVariableReference.h" |
| #include "ir/SkSLWhileStatement.h" |
| |
| namespace SkSL { |
| |
| class AutoSymbolTable { |
| public: |
| AutoSymbolTable(IRGenerator* ir) |
| : fIR(ir) |
| , fPrevious(fIR->fSymbolTable) { |
| fIR->pushSymbolTable(); |
| } |
| |
| ~AutoSymbolTable() { |
| fIR->popSymbolTable(); |
| ASSERT(fPrevious == fIR->fSymbolTable); |
| } |
| |
| IRGenerator* fIR; |
| std::shared_ptr<SymbolTable> fPrevious; |
| }; |
| |
| IRGenerator::IRGenerator(std::shared_ptr<SymbolTable> symbolTable, |
| ErrorReporter& errorReporter) |
| : fSymbolTable(std::move(symbolTable)) |
| , fErrors(errorReporter) { |
| } |
| |
| void IRGenerator::pushSymbolTable() { |
| fSymbolTable.reset(new SymbolTable(std::move(fSymbolTable), fErrors)); |
| } |
| |
| void IRGenerator::popSymbolTable() { |
| fSymbolTable = fSymbolTable->fParent; |
| } |
| |
| std::unique_ptr<Extension> IRGenerator::convertExtension(const ASTExtension& extension) { |
| return std::unique_ptr<Extension>(new Extension(extension.fPosition, extension.fName)); |
| } |
| |
| std::unique_ptr<Statement> IRGenerator::convertStatement(const ASTStatement& statement) { |
| switch (statement.fKind) { |
| case ASTStatement::kBlock_Kind: |
| return this->convertBlock((ASTBlock&) statement); |
| case ASTStatement::kVarDeclaration_Kind: |
| return this->convertVarDeclarationStatement((ASTVarDeclarationStatement&) statement); |
| case ASTStatement::kExpression_Kind: |
| return this->convertExpressionStatement((ASTExpressionStatement&) statement); |
| case ASTStatement::kIf_Kind: |
| return this->convertIf((ASTIfStatement&) statement); |
| case ASTStatement::kFor_Kind: |
| return this->convertFor((ASTForStatement&) statement); |
| case ASTStatement::kWhile_Kind: |
| return this->convertWhile((ASTWhileStatement&) statement); |
| case ASTStatement::kDo_Kind: |
| return this->convertDo((ASTDoStatement&) statement); |
| case ASTStatement::kReturn_Kind: |
| return this->convertReturn((ASTReturnStatement&) statement); |
| case ASTStatement::kBreak_Kind: |
| return this->convertBreak((ASTBreakStatement&) statement); |
| case ASTStatement::kContinue_Kind: |
| return this->convertContinue((ASTContinueStatement&) statement); |
| case ASTStatement::kDiscard_Kind: |
| return this->convertDiscard((ASTDiscardStatement&) statement); |
| default: |
| ABORT("unsupported statement type: %d\n", statement.fKind); |
| } |
| } |
| |
| std::unique_ptr<Block> IRGenerator::convertBlock(const ASTBlock& block) { |
| AutoSymbolTable table(this); |
| std::vector<std::unique_ptr<Statement>> statements; |
| for (size_t i = 0; i < block.fStatements.size(); i++) { |
| std::unique_ptr<Statement> statement = this->convertStatement(*block.fStatements[i]); |
| if (!statement) { |
| return nullptr; |
| } |
| statements.push_back(std::move(statement)); |
| } |
| return std::unique_ptr<Block>(new Block(block.fPosition, std::move(statements))); |
| } |
| |
| std::unique_ptr<Statement> IRGenerator::convertVarDeclarationStatement( |
| const ASTVarDeclarationStatement& s) { |
| auto decl = this->convertVarDeclaration(*s.fDeclaration, Variable::kLocal_Storage); |
| if (!decl) { |
| return nullptr; |
| } |
| return std::unique_ptr<Statement>(new VarDeclarationStatement(std::move(decl))); |
| } |
| |
| Modifiers IRGenerator::convertModifiers(const ASTModifiers& modifiers) { |
| return Modifiers(modifiers); |
| } |
| |
| std::unique_ptr<VarDeclaration> IRGenerator::convertVarDeclaration(const ASTVarDeclaration& decl, |
| Variable::Storage storage) { |
| std::vector<std::shared_ptr<Variable>> variables; |
| std::vector<std::vector<std::unique_ptr<Expression>>> sizes; |
| std::vector<std::unique_ptr<Expression>> values; |
| std::shared_ptr<Type> baseType = this->convertType(*decl.fType); |
| if (!baseType) { |
| return nullptr; |
| } |
| for (size_t i = 0; i < decl.fNames.size(); i++) { |
| Modifiers modifiers = this->convertModifiers(decl.fModifiers); |
| std::shared_ptr<Type> type = baseType; |
| ASSERT(type->kind() != Type::kArray_Kind); |
| std::vector<std::unique_ptr<Expression>> currentVarSizes; |
| for (size_t j = 0; j < decl.fSizes[i].size(); j++) { |
| if (decl.fSizes[i][j]) { |
| ASTExpression& rawSize = *decl.fSizes[i][j]; |
| auto size = this->coerce(this->convertExpression(rawSize), kInt_Type); |
| if (!size) { |
| return nullptr; |
| } |
| std::string name = type->fName; |
| uint64_t count; |
| if (size->fKind == Expression::kIntLiteral_Kind) { |
| count = ((IntLiteral&) *size).fValue; |
| if (count <= 0) { |
| fErrors.error(size->fPosition, "array size must be positive"); |
| } |
| name += "[" + to_string(count) + "]"; |
| } else { |
| count = -1; |
| name += "[]"; |
| } |
| type = std::shared_ptr<Type>(new Type(name, Type::kArray_Kind, type, (int) count)); |
| currentVarSizes.push_back(std::move(size)); |
| } else { |
| type = std::shared_ptr<Type>(new Type(type->fName + "[]", Type::kArray_Kind, type, |
| -1)); |
| currentVarSizes.push_back(nullptr); |
| } |
| } |
| sizes.push_back(std::move(currentVarSizes)); |
| auto var = std::make_shared<Variable>(decl.fPosition, modifiers, decl.fNames[i], type, |
| storage); |
| variables.push_back(var); |
| std::unique_ptr<Expression> value; |
| if (decl.fValues[i]) { |
| value = this->convertExpression(*decl.fValues[i]); |
| if (!value) { |
| return nullptr; |
| } |
| value = this->coerce(std::move(value), type); |
| } |
| fSymbolTable->add(var->fName, var); |
| values.push_back(std::move(value)); |
| } |
| return std::unique_ptr<VarDeclaration>(new VarDeclaration(decl.fPosition, std::move(variables), |
| std::move(sizes), std::move(values))); |
| } |
| |
| std::unique_ptr<Statement> IRGenerator::convertIf(const ASTIfStatement& s) { |
| std::unique_ptr<Expression> test = this->coerce(this->convertExpression(*s.fTest), kBool_Type); |
| if (!test) { |
| return nullptr; |
| } |
| std::unique_ptr<Statement> ifTrue = this->convertStatement(*s.fIfTrue); |
| if (!ifTrue) { |
| return nullptr; |
| } |
| std::unique_ptr<Statement> ifFalse; |
| if (s.fIfFalse) { |
| ifFalse = this->convertStatement(*s.fIfFalse); |
| if (!ifFalse) { |
| return nullptr; |
| } |
| } |
| return std::unique_ptr<Statement>(new IfStatement(s.fPosition, std::move(test), |
| std::move(ifTrue), std::move(ifFalse))); |
| } |
| |
| std::unique_ptr<Statement> IRGenerator::convertFor(const ASTForStatement& f) { |
| AutoSymbolTable table(this); |
| std::unique_ptr<Statement> initializer = this->convertStatement(*f.fInitializer); |
| if (!initializer) { |
| return nullptr; |
| } |
| std::unique_ptr<Expression> test = this->coerce(this->convertExpression(*f.fTest), kBool_Type); |
| if (!test) { |
| return nullptr; |
| } |
| std::unique_ptr<Expression> next = this->convertExpression(*f.fNext); |
| if (!next) { |
| return nullptr; |
| } |
| this->checkValid(*next); |
| std::unique_ptr<Statement> statement = this->convertStatement(*f.fStatement); |
| if (!statement) { |
| return nullptr; |
| } |
| return std::unique_ptr<Statement>(new ForStatement(f.fPosition, std::move(initializer), |
| std::move(test), std::move(next), |
| std::move(statement))); |
| } |
| |
| std::unique_ptr<Statement> IRGenerator::convertWhile(const ASTWhileStatement& w) { |
| std::unique_ptr<Expression> test = this->coerce(this->convertExpression(*w.fTest), kBool_Type); |
| if (!test) { |
| return nullptr; |
| } |
| std::unique_ptr<Statement> statement = this->convertStatement(*w.fStatement); |
| if (!statement) { |
| return nullptr; |
| } |
| return std::unique_ptr<Statement>(new WhileStatement(w.fPosition, std::move(test), |
| std::move(statement))); |
| } |
| |
| std::unique_ptr<Statement> IRGenerator::convertDo(const ASTDoStatement& d) { |
| std::unique_ptr<Expression> test = this->coerce(this->convertExpression(*d.fTest), kBool_Type); |
| if (!test) { |
| return nullptr; |
| } |
| std::unique_ptr<Statement> statement = this->convertStatement(*d.fStatement); |
| if (!statement) { |
| return nullptr; |
| } |
| return std::unique_ptr<Statement>(new DoStatement(d.fPosition, std::move(statement), |
| std::move(test))); |
| } |
| |
| std::unique_ptr<Statement> IRGenerator::convertExpressionStatement( |
| const ASTExpressionStatement& s) { |
| std::unique_ptr<Expression> e = this->convertExpression(*s.fExpression); |
| if (!e) { |
| return nullptr; |
| } |
| this->checkValid(*e); |
| return std::unique_ptr<Statement>(new ExpressionStatement(std::move(e))); |
| } |
| |
| std::unique_ptr<Statement> IRGenerator::convertReturn(const ASTReturnStatement& r) { |
| ASSERT(fCurrentFunction); |
| if (r.fExpression) { |
| std::unique_ptr<Expression> result = this->convertExpression(*r.fExpression); |
| if (!result) { |
| return nullptr; |
| } |
| if (fCurrentFunction->fReturnType == kVoid_Type) { |
| fErrors.error(result->fPosition, "may not return a value from a void function"); |
| } else { |
| result = this->coerce(std::move(result), fCurrentFunction->fReturnType); |
| if (!result) { |
| return nullptr; |
| } |
| } |
| return std::unique_ptr<Statement>(new ReturnStatement(std::move(result))); |
| } else { |
| if (fCurrentFunction->fReturnType != kVoid_Type) { |
| fErrors.error(r.fPosition, "expected function to return '" + |
| fCurrentFunction->fReturnType->description() + "'"); |
| } |
| return std::unique_ptr<Statement>(new ReturnStatement(r.fPosition)); |
| } |
| } |
| |
| std::unique_ptr<Statement> IRGenerator::convertBreak(const ASTBreakStatement& b) { |
| return std::unique_ptr<Statement>(new BreakStatement(b.fPosition)); |
| } |
| |
| std::unique_ptr<Statement> IRGenerator::convertContinue(const ASTContinueStatement& c) { |
| return std::unique_ptr<Statement>(new ContinueStatement(c.fPosition)); |
| } |
| |
| std::unique_ptr<Statement> IRGenerator::convertDiscard(const ASTDiscardStatement& d) { |
| return std::unique_ptr<Statement>(new DiscardStatement(d.fPosition)); |
| } |
| |
| static std::shared_ptr<Type> expand_generics(std::shared_ptr<Type> type, int i) { |
| if (type->kind() == Type::kGeneric_Kind) { |
| return type->coercibleTypes()[i]; |
| } |
| return type; |
| } |
| |
| static void expand_generics(FunctionDeclaration& decl, |
| SymbolTable& symbolTable) { |
| for (int i = 0; i < 4; i++) { |
| std::shared_ptr<Type> returnType = expand_generics(decl.fReturnType, i); |
| std::vector<std::shared_ptr<Variable>> arguments; |
| for (const auto& p : decl.fParameters) { |
| arguments.push_back(std::shared_ptr<Variable>(new Variable( |
| p->fPosition, |
| Modifiers(p->fModifiers), |
| p->fName, |
| expand_generics(p->fType, i), |
| Variable::kParameter_Storage))); |
| } |
| std::shared_ptr<FunctionDeclaration> expanded(new FunctionDeclaration( |
| decl.fPosition, |
| decl.fName, |
| std::move(arguments), |
| std::move(returnType))); |
| symbolTable.add(expanded->fName, expanded); |
| } |
| } |
| |
| std::unique_ptr<FunctionDefinition> IRGenerator::convertFunction(const ASTFunction& f) { |
| std::shared_ptr<SymbolTable> old = fSymbolTable; |
| AutoSymbolTable table(this); |
| bool isGeneric; |
| std::shared_ptr<Type> returnType = this->convertType(*f.fReturnType); |
| if (!returnType) { |
| return nullptr; |
| } |
| isGeneric = returnType->kind() == Type::kGeneric_Kind; |
| std::vector<std::shared_ptr<Variable>> parameters; |
| for (const auto& param : f.fParameters) { |
| std::shared_ptr<Type> type = this->convertType(*param->fType); |
| if (!type) { |
| return nullptr; |
| } |
| for (int j = (int) param->fSizes.size() - 1; j >= 0; j--) { |
| int size = param->fSizes[j]; |
| std::string name = type->name() + "[" + to_string(size) + "]"; |
| type = std::shared_ptr<Type>(new Type(std::move(name), Type::kArray_Kind, |
| std::move(type), size)); |
| } |
| std::string name = param->fName; |
| Modifiers modifiers = this->convertModifiers(param->fModifiers); |
| Position pos = param->fPosition; |
| std::shared_ptr<Variable> var = std::shared_ptr<Variable>(new Variable( |
| pos, |
| modifiers, |
| std::move(name), |
| type, |
| Variable::kParameter_Storage)); |
| parameters.push_back(std::move(var)); |
| isGeneric |= type->kind() == Type::kGeneric_Kind; |
| } |
| |
| // find existing declaration |
| std::shared_ptr<FunctionDeclaration> decl; |
| auto entry = (*old)[f.fName]; |
| if (entry) { |
| std::vector<std::shared_ptr<FunctionDeclaration>> functions; |
| switch (entry->fKind) { |
| case Symbol::kUnresolvedFunction_Kind: |
| functions = std::static_pointer_cast<UnresolvedFunction>(entry)->fFunctions; |
| break; |
| case Symbol::kFunctionDeclaration_Kind: |
| functions.push_back(std::static_pointer_cast<FunctionDeclaration>(entry)); |
| break; |
| default: |
| fErrors.error(f.fPosition, "symbol '" + f.fName + "' was already defined"); |
| return nullptr; |
| } |
| for (const auto& other : functions) { |
| ASSERT(other->fName == f.fName); |
| if (parameters.size() == other->fParameters.size()) { |
| bool match = true; |
| for (size_t i = 0; i < parameters.size(); i++) { |
| if (parameters[i]->fType != other->fParameters[i]->fType) { |
| match = false; |
| break; |
| } |
| } |
| if (match) { |
| if (returnType != other->fReturnType) { |
| FunctionDeclaration newDecl = FunctionDeclaration(f.fPosition, |
| f.fName, |
| parameters, |
| returnType); |
| fErrors.error(f.fPosition, "functions '" + newDecl.description() + |
| "' and '" + other->description() + |
| "' differ only in return type"); |
| return nullptr; |
| } |
| decl = other; |
| for (size_t i = 0; i < parameters.size(); i++) { |
| if (parameters[i]->fModifiers != other->fParameters[i]->fModifiers) { |
| fErrors.error(f.fPosition, "modifiers on parameter " + |
| to_string(i + 1) + " differ between " + |
| "declaration and definition"); |
| return nullptr; |
| } |
| fSymbolTable->add(parameters[i]->fName, decl->fParameters[i]); |
| } |
| if (other->fDefined) { |
| fErrors.error(f.fPosition, "duplicate definition of " + |
| other->description()); |
| } |
| break; |
| } |
| } |
| } |
| } |
| if (!decl) { |
| // couldn't find an existing declaration |
| decl.reset(new FunctionDeclaration(f.fPosition, f.fName, parameters, returnType)); |
| for (auto var : parameters) { |
| fSymbolTable->add(var->fName, var); |
| } |
| } |
| if (isGeneric) { |
| ASSERT(!f.fBody); |
| expand_generics(*decl, *old); |
| } else { |
| old->add(decl->fName, decl); |
| if (f.fBody) { |
| ASSERT(!fCurrentFunction); |
| fCurrentFunction = decl; |
| decl->fDefined = true; |
| std::unique_ptr<Block> body = this->convertBlock(*f.fBody); |
| fCurrentFunction = nullptr; |
| if (!body) { |
| return nullptr; |
| } |
| return std::unique_ptr<FunctionDefinition>(new FunctionDefinition(f.fPosition, decl, |
| std::move(body))); |
| } |
| } |
| return nullptr; |
| } |
| |
| std::unique_ptr<InterfaceBlock> IRGenerator::convertInterfaceBlock(const ASTInterfaceBlock& intf) { |
| std::shared_ptr<SymbolTable> old = fSymbolTable; |
| AutoSymbolTable table(this); |
| Modifiers mods = this->convertModifiers(intf.fModifiers); |
| std::vector<Type::Field> fields; |
| for (size_t i = 0; i < intf.fDeclarations.size(); i++) { |
| std::unique_ptr<VarDeclaration> decl = this->convertVarDeclaration( |
| *intf.fDeclarations[i], |
| Variable::kGlobal_Storage); |
| for (size_t j = 0; j < decl->fVars.size(); j++) { |
| fields.push_back(Type::Field(decl->fVars[j]->fModifiers, decl->fVars[j]->fName, |
| decl->fVars[j]->fType)); |
| if (decl->fValues[j]) { |
| fErrors.error(decl->fPosition, |
| "initializers are not permitted on interface block fields"); |
| } |
| if (decl->fVars[j]->fModifiers.fFlags & (Modifiers::kIn_Flag | |
| Modifiers::kOut_Flag | |
| Modifiers::kUniform_Flag | |
| Modifiers::kConst_Flag)) { |
| fErrors.error(decl->fPosition, |
| "interface block fields may not have storage qualifiers"); |
| } |
| } |
| } |
| std::shared_ptr<Type> type = std::shared_ptr<Type>(new Type(intf.fInterfaceName, fields)); |
| std::string name = intf.fValueName.length() > 0 ? intf.fValueName : intf.fInterfaceName; |
| std::shared_ptr<Variable> var = std::shared_ptr<Variable>(new Variable(intf.fPosition, mods, |
| name, type, |
| Variable::kGlobal_Storage)); |
| if (intf.fValueName.length()) { |
| old->add(intf.fValueName, var); |
| |
| } else { |
| for (size_t i = 0; i < fields.size(); i++) { |
| std::shared_ptr<Field> field = std::shared_ptr<Field>(new Field(intf.fPosition, var, |
| (int) i)); |
| old->add(fields[i].fName, field); |
| } |
| } |
| return std::unique_ptr<InterfaceBlock>(new InterfaceBlock(intf.fPosition, var)); |
| } |
| |
| std::shared_ptr<Type> IRGenerator::convertType(const ASTType& type) { |
| std::shared_ptr<Symbol> result = (*fSymbolTable)[type.fName]; |
| if (result && result->fKind == Symbol::kType_Kind) { |
| return std::static_pointer_cast<Type>(result); |
| } |
| fErrors.error(type.fPosition, "unknown type '" + type.fName + "'"); |
| return nullptr; |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::convertExpression(const ASTExpression& expr) { |
| switch (expr.fKind) { |
| case ASTExpression::kIdentifier_Kind: |
| return this->convertIdentifier((ASTIdentifier&) expr); |
| case ASTExpression::kBool_Kind: |
| return std::unique_ptr<Expression>(new BoolLiteral(expr.fPosition, |
| ((ASTBoolLiteral&) expr).fValue)); |
| case ASTExpression::kInt_Kind: |
| return std::unique_ptr<Expression>(new IntLiteral(expr.fPosition, |
| ((ASTIntLiteral&) expr).fValue)); |
| case ASTExpression::kFloat_Kind: |
| return std::unique_ptr<Expression>(new FloatLiteral(expr.fPosition, |
| ((ASTFloatLiteral&) expr).fValue)); |
| case ASTExpression::kBinary_Kind: |
| return this->convertBinaryExpression((ASTBinaryExpression&) expr); |
| case ASTExpression::kPrefix_Kind: |
| return this->convertPrefixExpression((ASTPrefixExpression&) expr); |
| case ASTExpression::kSuffix_Kind: |
| return this->convertSuffixExpression((ASTSuffixExpression&) expr); |
| case ASTExpression::kTernary_Kind: |
| return this->convertTernaryExpression((ASTTernaryExpression&) expr); |
| default: |
| ABORT("unsupported expression type: %d\n", expr.fKind); |
| } |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::convertIdentifier(const ASTIdentifier& identifier) { |
| std::shared_ptr<Symbol> result = (*fSymbolTable)[identifier.fText]; |
| if (!result) { |
| fErrors.error(identifier.fPosition, "unknown identifier '" + identifier.fText + "'"); |
| return nullptr; |
| } |
| switch (result->fKind) { |
| case Symbol::kFunctionDeclaration_Kind: { |
| std::vector<std::shared_ptr<FunctionDeclaration>> f = { |
| std::static_pointer_cast<FunctionDeclaration>(result) |
| }; |
| return std::unique_ptr<FunctionReference>(new FunctionReference(identifier.fPosition, |
| std::move(f))); |
| } |
| case Symbol::kUnresolvedFunction_Kind: { |
| auto f = std::static_pointer_cast<UnresolvedFunction>(result); |
| return std::unique_ptr<FunctionReference>(new FunctionReference(identifier.fPosition, |
| f->fFunctions)); |
| } |
| case Symbol::kVariable_Kind: { |
| std::shared_ptr<Variable> var = std::static_pointer_cast<Variable>(result); |
| this->markReadFrom(var); |
| return std::unique_ptr<VariableReference>(new VariableReference(identifier.fPosition, |
| std::move(var))); |
| } |
| case Symbol::kField_Kind: { |
| std::shared_ptr<Field> field = std::static_pointer_cast<Field>(result); |
| VariableReference* base = new VariableReference(identifier.fPosition, field->fOwner); |
| return std::unique_ptr<Expression>(new FieldAccess(std::unique_ptr<Expression>(base), |
| field->fFieldIndex)); |
| } |
| case Symbol::kType_Kind: { |
| auto t = std::static_pointer_cast<Type>(result); |
| return std::unique_ptr<TypeReference>(new TypeReference(identifier.fPosition, |
| std::move(t))); |
| } |
| default: |
| ABORT("unsupported symbol type %d\n", result->fKind); |
| } |
| |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::coerce(std::unique_ptr<Expression> expr, |
| std::shared_ptr<Type> type) { |
| if (!expr) { |
| return nullptr; |
| } |
| if (*expr->fType == *type) { |
| return expr; |
| } |
| this->checkValid(*expr); |
| if (*expr->fType == *kInvalid_Type) { |
| return nullptr; |
| } |
| if (!expr->fType->canCoerceTo(type)) { |
| fErrors.error(expr->fPosition, "expected '" + type->description() + "', but found '" + |
| expr->fType->description() + "'"); |
| return nullptr; |
| } |
| if (type->kind() == Type::kScalar_Kind) { |
| std::vector<std::unique_ptr<Expression>> args; |
| args.push_back(std::move(expr)); |
| ASTIdentifier id(Position(), type->description()); |
| std::unique_ptr<Expression> ctor = this->convertIdentifier(id); |
| ASSERT(ctor); |
| return this->call(Position(), std::move(ctor), std::move(args)); |
| } |
| ABORT("cannot coerce %s to %s", expr->fType->description().c_str(), |
| type->description().c_str()); |
| } |
| |
| /** |
| * Determines the operand and result types of a binary expression. Returns true if the expression is |
| * legal, false otherwise. If false, the values of the out parameters are undefined. |
| */ |
| static bool determine_binary_type(Token::Kind op, std::shared_ptr<Type> left, |
| std::shared_ptr<Type> right, |
| std::shared_ptr<Type>* outLeftType, |
| std::shared_ptr<Type>* outRightType, |
| std::shared_ptr<Type>* outResultType, |
| bool tryFlipped) { |
| bool isLogical; |
| switch (op) { |
| case Token::EQEQ: // fall through |
| case Token::NEQ: // fall through |
| case Token::LT: // fall through |
| case Token::GT: // fall through |
| case Token::LTEQ: // fall through |
| case Token::GTEQ: |
| isLogical = true; |
| break; |
| case Token::LOGICALOR: // fall through |
| case Token::LOGICALAND: // fall through |
| case Token::LOGICALXOR: // fall through |
| case Token::LOGICALOREQ: // fall through |
| case Token::LOGICALANDEQ: // fall through |
| case Token::LOGICALXOREQ: |
| *outLeftType = kBool_Type; |
| *outRightType = kBool_Type; |
| *outResultType = kBool_Type; |
| return left->canCoerceTo(kBool_Type) && right->canCoerceTo(kBool_Type); |
| case Token::STAR: // fall through |
| case Token::STAREQ: |
| // FIXME need to handle non-square matrices |
| if (left->kind() == Type::kMatrix_Kind && right->kind() == Type::kVector_Kind) { |
| *outLeftType = left; |
| *outRightType = right; |
| *outResultType = right; |
| return left->rows() == right->columns(); |
| } |
| if (left->kind() == Type::kVector_Kind && right->kind() == Type::kMatrix_Kind) { |
| *outLeftType = left; |
| *outRightType = right; |
| *outResultType = left; |
| return left->columns() == right->columns(); |
| } |
| // fall through |
| default: |
| isLogical = false; |
| } |
| // FIXME: need to disallow illegal operations like vec3 > vec3. Also do not currently have |
| // full support for numbers other than float. |
| if (left == right) { |
| *outLeftType = left; |
| *outRightType = left; |
| if (isLogical) { |
| *outResultType = kBool_Type; |
| } else { |
| *outResultType = left; |
| } |
| return true; |
| } |
| // FIXME: incorrect for shift operations |
| if (left->canCoerceTo(right)) { |
| *outLeftType = right; |
| *outRightType = right; |
| if (isLogical) { |
| *outResultType = kBool_Type; |
| } else { |
| *outResultType = right; |
| } |
| return true; |
| } |
| if ((left->kind() == Type::kVector_Kind || left->kind() == Type::kMatrix_Kind) && |
| (right->kind() == Type::kScalar_Kind)) { |
| if (determine_binary_type(op, left->componentType(), right, outLeftType, outRightType, |
| outResultType, false)) { |
| *outLeftType = (*outLeftType)->toCompound(left->columns(), left->rows()); |
| if (!isLogical) { |
| *outResultType = (*outResultType)->toCompound(left->columns(), left->rows()); |
| } |
| return true; |
| } |
| return false; |
| } |
| if (tryFlipped) { |
| return determine_binary_type(op, right, left, outRightType, outLeftType, outResultType, |
| false); |
| } |
| return false; |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::convertBinaryExpression( |
| const ASTBinaryExpression& expression) { |
| std::unique_ptr<Expression> left = this->convertExpression(*expression.fLeft); |
| if (!left) { |
| return nullptr; |
| } |
| std::unique_ptr<Expression> right = this->convertExpression(*expression.fRight); |
| if (!right) { |
| return nullptr; |
| } |
| std::shared_ptr<Type> leftType; |
| std::shared_ptr<Type> rightType; |
| std::shared_ptr<Type> resultType; |
| if (!determine_binary_type(expression.fOperator, left->fType, right->fType, &leftType, |
| &rightType, &resultType, true)) { |
| fErrors.error(expression.fPosition, "type mismatch: '" + |
| Token::OperatorName(expression.fOperator) + |
| "' cannot operate on '" + left->fType->fName + |
| "', '" + right->fType->fName + "'"); |
| return nullptr; |
| } |
| switch (expression.fOperator) { |
| case Token::EQ: // fall through |
| case Token::PLUSEQ: // fall through |
| case Token::MINUSEQ: // fall through |
| case Token::STAREQ: // fall through |
| case Token::SLASHEQ: // fall through |
| case Token::PERCENTEQ: // fall through |
| case Token::SHLEQ: // fall through |
| case Token::SHREQ: // fall through |
| case Token::BITWISEOREQ: // fall through |
| case Token::BITWISEXOREQ: // fall through |
| case Token::BITWISEANDEQ: // fall through |
| case Token::LOGICALOREQ: // fall through |
| case Token::LOGICALXOREQ: // fall through |
| case Token::LOGICALANDEQ: |
| this->markWrittenTo(*left); |
| default: |
| break; |
| } |
| return std::unique_ptr<Expression>(new BinaryExpression(expression.fPosition, |
| this->coerce(std::move(left), leftType), |
| expression.fOperator, |
| this->coerce(std::move(right), |
| rightType), |
| resultType)); |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::convertTernaryExpression( |
| const ASTTernaryExpression& expression) { |
| std::unique_ptr<Expression> test = this->coerce(this->convertExpression(*expression.fTest), |
| kBool_Type); |
| if (!test) { |
| return nullptr; |
| } |
| std::unique_ptr<Expression> ifTrue = this->convertExpression(*expression.fIfTrue); |
| if (!ifTrue) { |
| return nullptr; |
| } |
| std::unique_ptr<Expression> ifFalse = this->convertExpression(*expression.fIfFalse); |
| if (!ifFalse) { |
| return nullptr; |
| } |
| std::shared_ptr<Type> trueType; |
| std::shared_ptr<Type> falseType; |
| std::shared_ptr<Type> resultType; |
| if (!determine_binary_type(Token::EQEQ, ifTrue->fType, ifFalse->fType, &trueType, |
| &falseType, &resultType, true)) { |
| fErrors.error(expression.fPosition, "ternary operator result mismatch: '" + |
| ifTrue->fType->fName + "', '" + |
| ifFalse->fType->fName + "'"); |
| return nullptr; |
| } |
| ASSERT(trueType == falseType); |
| ifTrue = this->coerce(std::move(ifTrue), trueType); |
| ifFalse = this->coerce(std::move(ifFalse), falseType); |
| return std::unique_ptr<Expression>(new TernaryExpression(expression.fPosition, |
| std::move(test), |
| std::move(ifTrue), |
| std::move(ifFalse))); |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::call( |
| Position position, |
| std::shared_ptr<FunctionDeclaration> function, |
| std::vector<std::unique_ptr<Expression>> arguments) { |
| if (function->fParameters.size() != arguments.size()) { |
| std::string msg = "call to '" + function->fName + "' expected " + |
| to_string(function->fParameters.size()) + |
| " argument"; |
| if (function->fParameters.size() != 1) { |
| msg += "s"; |
| } |
| msg += ", but found " + to_string(arguments.size()); |
| fErrors.error(position, msg); |
| return nullptr; |
| } |
| for (size_t i = 0; i < arguments.size(); i++) { |
| arguments[i] = this->coerce(std::move(arguments[i]), function->fParameters[i]->fType); |
| if (arguments[i] && (function->fParameters[i]->fModifiers.fFlags & Modifiers::kOut_Flag)) { |
| this->markWrittenTo(*arguments[i]); |
| } |
| } |
| return std::unique_ptr<FunctionCall>(new FunctionCall(position, std::move(function), |
| std::move(arguments))); |
| } |
| |
| /** |
| * Determines the cost of coercing the arguments of a function to the required types. Returns true |
| * if the cost could be computed, false if the call is not valid. Cost has no particular meaning |
| * other than "lower costs are preferred". |
| */ |
| bool IRGenerator::determineCallCost(std::shared_ptr<FunctionDeclaration> function, |
| const std::vector<std::unique_ptr<Expression>>& arguments, |
| int* outCost) { |
| if (function->fParameters.size() != arguments.size()) { |
| return false; |
| } |
| int total = 0; |
| for (size_t i = 0; i < arguments.size(); i++) { |
| int cost; |
| if (arguments[i]->fType->determineCoercionCost(function->fParameters[i]->fType, &cost)) { |
| total += cost; |
| } else { |
| return false; |
| } |
| } |
| *outCost = total; |
| return true; |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::call(Position position, |
| std::unique_ptr<Expression> functionValue, |
| std::vector<std::unique_ptr<Expression>> arguments) { |
| if (functionValue->fKind == Expression::kTypeReference_Kind) { |
| return this->convertConstructor(position, |
| ((TypeReference&) *functionValue).fValue, |
| std::move(arguments)); |
| } |
| if (functionValue->fKind != Expression::kFunctionReference_Kind) { |
| fErrors.error(position, "'" + functionValue->description() + "' is not a function"); |
| return nullptr; |
| } |
| FunctionReference* ref = (FunctionReference*) functionValue.get(); |
| int bestCost = INT_MAX; |
| std::shared_ptr<FunctionDeclaration> best; |
| if (ref->fFunctions.size() > 1) { |
| for (const auto& f : ref->fFunctions) { |
| int cost; |
| if (this->determineCallCost(f, arguments, &cost) && cost < bestCost) { |
| bestCost = cost; |
| best = f; |
| } |
| } |
| if (best) { |
| return this->call(position, std::move(best), std::move(arguments)); |
| } |
| std::string msg = "no match for " + ref->fFunctions[0]->fName + "("; |
| std::string separator = ""; |
| for (size_t i = 0; i < arguments.size(); i++) { |
| msg += separator; |
| separator = ", "; |
| msg += arguments[i]->fType->description(); |
| } |
| msg += ")"; |
| fErrors.error(position, msg); |
| return nullptr; |
| } |
| return this->call(position, ref->fFunctions[0], std::move(arguments)); |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::convertConstructor( |
| Position position, |
| std::shared_ptr<Type> type, |
| std::vector<std::unique_ptr<Expression>> args) { |
| // FIXME: add support for structs and arrays |
| Type::Kind kind = type->kind(); |
| if (!type->isNumber() && kind != Type::kVector_Kind && kind != Type::kMatrix_Kind) { |
| fErrors.error(position, "cannot construct '" + type->description() + "'"); |
| return nullptr; |
| } |
| if (type == kFloat_Type && args.size() == 1 && |
| args[0]->fKind == Expression::kIntLiteral_Kind) { |
| int64_t value = ((IntLiteral&) *args[0]).fValue; |
| return std::unique_ptr<Expression>(new FloatLiteral(position, (double) value)); |
| } |
| if (args.size() == 1 && args[0]->fType == type) { |
| // argument is already the right type, just return it |
| return std::move(args[0]); |
| } |
| if (type->isNumber()) { |
| if (args.size() != 1) { |
| fErrors.error(position, "invalid arguments to '" + type->description() + |
| "' constructor, (expected exactly 1 argument, but found " + |
| to_string(args.size()) + ")"); |
| } |
| if (args[0]->fType == kBool_Type) { |
| std::unique_ptr<IntLiteral> zero(new IntLiteral(position, 0)); |
| std::unique_ptr<IntLiteral> one(new IntLiteral(position, 1)); |
| return std::unique_ptr<Expression>( |
| new TernaryExpression(position, std::move(args[0]), |
| this->coerce(std::move(one), type), |
| this->coerce(std::move(zero), |
| type))); |
| } else if (!args[0]->fType->isNumber()) { |
| fErrors.error(position, "invalid argument to '" + type->description() + |
| "' constructor (expected a number or bool, but found '" + |
| args[0]->fType->description() + "')"); |
| } |
| } else { |
| ASSERT(kind == Type::kVector_Kind || kind == Type::kMatrix_Kind); |
| int actual = 0; |
| for (size_t i = 0; i < args.size(); i++) { |
| if (args[i]->fType->kind() == Type::kVector_Kind || |
| args[i]->fType->kind() == Type::kMatrix_Kind) { |
| int columns = args[i]->fType->columns(); |
| int rows = args[i]->fType->rows(); |
| args[i] = this->coerce(std::move(args[i]), |
| type->componentType()->toCompound(columns, rows)); |
| actual += args[i]->fType->rows() * args[i]->fType->columns(); |
| } else if (args[i]->fType->kind() == Type::kScalar_Kind) { |
| actual += 1; |
| if (type->kind() != Type::kScalar_Kind) { |
| args[i] = this->coerce(std::move(args[i]), type->componentType()); |
| } |
| } else { |
| fErrors.error(position, "'" + args[i]->fType->description() + "' is not a valid " |
| "parameter to '" + type->description() + "' constructor"); |
| return nullptr; |
| } |
| } |
| int min = type->rows() * type->columns(); |
| int max = type->columns() > 1 ? INT_MAX : min; |
| if ((actual < min || actual > max) && |
| !((kind == Type::kVector_Kind || kind == Type::kMatrix_Kind) && (actual == 1))) { |
| fErrors.error(position, "invalid arguments to '" + type->description() + |
| "' constructor (expected " + to_string(min) + " scalar" + |
| (min == 1 ? "" : "s") + ", but found " + to_string(actual) + |
| ")"); |
| return nullptr; |
| } |
| } |
| return std::unique_ptr<Expression>(new Constructor(position, std::move(type), std::move(args))); |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::convertPrefixExpression( |
| const ASTPrefixExpression& expression) { |
| std::unique_ptr<Expression> base = this->convertExpression(*expression.fOperand); |
| if (!base) { |
| return nullptr; |
| } |
| switch (expression.fOperator) { |
| case Token::PLUS: |
| if (!base->fType->isNumber() && base->fType->kind() != Type::kVector_Kind) { |
| fErrors.error(expression.fPosition, |
| "'+' cannot operate on '" + base->fType->description() + "'"); |
| return nullptr; |
| } |
| return base; |
| case Token::MINUS: |
| if (!base->fType->isNumber() && base->fType->kind() != Type::kVector_Kind) { |
| fErrors.error(expression.fPosition, |
| "'-' cannot operate on '" + base->fType->description() + "'"); |
| return nullptr; |
| } |
| if (base->fKind == Expression::kIntLiteral_Kind) { |
| return std::unique_ptr<Expression>(new IntLiteral(base->fPosition, |
| -((IntLiteral&) *base).fValue)); |
| } |
| if (base->fKind == Expression::kFloatLiteral_Kind) { |
| double value = -((FloatLiteral&) *base).fValue; |
| return std::unique_ptr<Expression>(new FloatLiteral(base->fPosition, value)); |
| } |
| return std::unique_ptr<Expression>(new PrefixExpression(Token::MINUS, std::move(base))); |
| case Token::PLUSPLUS: |
| if (!base->fType->isNumber()) { |
| fErrors.error(expression.fPosition, |
| "'" + Token::OperatorName(expression.fOperator) + |
| "' cannot operate on '" + base->fType->description() + "'"); |
| return nullptr; |
| } |
| this->markWrittenTo(*base); |
| break; |
| case Token::MINUSMINUS: |
| if (!base->fType->isNumber()) { |
| fErrors.error(expression.fPosition, |
| "'" + Token::OperatorName(expression.fOperator) + |
| "' cannot operate on '" + base->fType->description() + "'"); |
| return nullptr; |
| } |
| this->markWrittenTo(*base); |
| break; |
| case Token::NOT: |
| if (base->fType != kBool_Type) { |
| fErrors.error(expression.fPosition, |
| "'" + Token::OperatorName(expression.fOperator) + |
| "' cannot operate on '" + base->fType->description() + "'"); |
| return nullptr; |
| } |
| break; |
| default: |
| ABORT("unsupported prefix operator\n"); |
| } |
| return std::unique_ptr<Expression>(new PrefixExpression(expression.fOperator, |
| std::move(base))); |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::convertIndex(std::unique_ptr<Expression> base, |
| const ASTExpression& index) { |
| if (base->fType->kind() != Type::kArray_Kind && base->fType->kind() != Type::kMatrix_Kind) { |
| fErrors.error(base->fPosition, "expected array, but found '" + base->fType->description() + |
| "'"); |
| return nullptr; |
| } |
| std::unique_ptr<Expression> converted = this->convertExpression(index); |
| if (!converted) { |
| return nullptr; |
| } |
| converted = this->coerce(std::move(converted), kInt_Type); |
| if (!converted) { |
| return nullptr; |
| } |
| return std::unique_ptr<Expression>(new IndexExpression(std::move(base), std::move(converted))); |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::convertField(std::unique_ptr<Expression> base, |
| const std::string& field) { |
| auto fields = base->fType->fields(); |
| for (size_t i = 0; i < fields.size(); i++) { |
| if (fields[i].fName == field) { |
| return std::unique_ptr<Expression>(new FieldAccess(std::move(base), (int) i)); |
| } |
| } |
| fErrors.error(base->fPosition, "type '" + base->fType->description() + "' does not have a " |
| "field named '" + field + ""); |
| return nullptr; |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::convertSwizzle(std::unique_ptr<Expression> base, |
| const std::string& fields) { |
| if (base->fType->kind() != Type::kVector_Kind) { |
| fErrors.error(base->fPosition, "cannot swizzle type '" + base->fType->description() + "'"); |
| return nullptr; |
| } |
| std::vector<int> swizzleComponents; |
| for (char c : fields) { |
| switch (c) { |
| case 'x': // fall through |
| case 'r': // fall through |
| case 's': |
| swizzleComponents.push_back(0); |
| break; |
| case 'y': // fall through |
| case 'g': // fall through |
| case 't': |
| if (base->fType->columns() >= 2) { |
| swizzleComponents.push_back(1); |
| break; |
| } |
| // fall through |
| case 'z': // fall through |
| case 'b': // fall through |
| case 'p': |
| if (base->fType->columns() >= 3) { |
| swizzleComponents.push_back(2); |
| break; |
| } |
| // fall through |
| case 'w': // fall through |
| case 'a': // fall through |
| case 'q': |
| if (base->fType->columns() >= 4) { |
| swizzleComponents.push_back(3); |
| break; |
| } |
| // fall through |
| default: |
| fErrors.error(base->fPosition, "invalid swizzle component '" + std::string(1, c) + |
| "'"); |
| return nullptr; |
| } |
| } |
| ASSERT(swizzleComponents.size() > 0); |
| if (swizzleComponents.size() > 4) { |
| fErrors.error(base->fPosition, "too many components in swizzle mask '" + fields + "'"); |
| return nullptr; |
| } |
| return std::unique_ptr<Expression>(new Swizzle(std::move(base), swizzleComponents)); |
| } |
| |
| std::unique_ptr<Expression> IRGenerator::convertSuffixExpression( |
| const ASTSuffixExpression& expression) { |
| std::unique_ptr<Expression> base = this->convertExpression(*expression.fBase); |
| if (!base) { |
| return nullptr; |
| } |
| switch (expression.fSuffix->fKind) { |
| case ASTSuffix::kIndex_Kind: |
| return this->convertIndex(std::move(base), |
| *((ASTIndexSuffix&) *expression.fSuffix).fExpression); |
| case ASTSuffix::kCall_Kind: { |
| auto rawArguments = &((ASTCallSuffix&) *expression.fSuffix).fArguments; |
| std::vector<std::unique_ptr<Expression>> arguments; |
| for (size_t i = 0; i < rawArguments->size(); i++) { |
| std::unique_ptr<Expression> converted = |
| this->convertExpression(*(*rawArguments)[i]); |
| if (!converted) { |
| return nullptr; |
| } |
| arguments.push_back(std::move(converted)); |
| } |
| return this->call(expression.fPosition, std::move(base), std::move(arguments)); |
| } |
| case ASTSuffix::kField_Kind: { |
| switch (base->fType->kind()) { |
| case Type::kVector_Kind: |
| return this->convertSwizzle(std::move(base), |
| ((ASTFieldSuffix&) *expression.fSuffix).fField); |
| case Type::kStruct_Kind: |
| return this->convertField(std::move(base), |
| ((ASTFieldSuffix&) *expression.fSuffix).fField); |
| default: |
| fErrors.error(base->fPosition, "cannot swizzle value of type '" + |
| base->fType->description() + "'"); |
| return nullptr; |
| } |
| } |
| case ASTSuffix::kPostIncrement_Kind: |
| if (!base->fType->isNumber()) { |
| fErrors.error(expression.fPosition, |
| "'++' cannot operate on '" + base->fType->description() + "'"); |
| return nullptr; |
| } |
| this->markWrittenTo(*base); |
| return std::unique_ptr<Expression>(new PostfixExpression(std::move(base), |
| Token::PLUSPLUS)); |
| case ASTSuffix::kPostDecrement_Kind: |
| if (!base->fType->isNumber()) { |
| fErrors.error(expression.fPosition, |
| "'--' cannot operate on '" + base->fType->description() + "'"); |
| return nullptr; |
| } |
| this->markWrittenTo(*base); |
| return std::unique_ptr<Expression>(new PostfixExpression(std::move(base), |
| Token::MINUSMINUS)); |
| default: |
| ABORT("unsupported suffix operator"); |
| } |
| } |
| |
| void IRGenerator::checkValid(const Expression& expr) { |
| switch (expr.fKind) { |
| case Expression::kFunctionReference_Kind: |
| fErrors.error(expr.fPosition, "expected '(' to begin function call"); |
| break; |
| case Expression::kTypeReference_Kind: |
| fErrors.error(expr.fPosition, "expected '(' to begin constructor invocation"); |
| break; |
| default: |
| ASSERT(expr.fType != kInvalid_Type); |
| break; |
| } |
| } |
| |
| void IRGenerator::markReadFrom(std::shared_ptr<Variable> var) { |
| var->fIsReadFrom = true; |
| } |
| |
| static bool has_duplicates(const Swizzle& swizzle) { |
| int bits = 0; |
| for (int idx : swizzle.fComponents) { |
| ASSERT(idx >= 0 && idx <= 3); |
| int bit = 1 << idx; |
| if (bits & bit) { |
| return true; |
| } |
| bits |= bit; |
| } |
| return false; |
| } |
| |
| void IRGenerator::markWrittenTo(const Expression& expr) { |
| switch (expr.fKind) { |
| case Expression::kVariableReference_Kind: { |
| const Variable& var = *((VariableReference&) expr).fVariable; |
| if (var.fModifiers.fFlags & (Modifiers::kConst_Flag | Modifiers::kUniform_Flag)) { |
| fErrors.error(expr.fPosition, |
| "cannot modify immutable variable '" + var.fName + "'"); |
| } |
| var.fIsWrittenTo = true; |
| break; |
| } |
| case Expression::kFieldAccess_Kind: |
| this->markWrittenTo(*((FieldAccess&) expr).fBase); |
| break; |
| case Expression::kSwizzle_Kind: |
| if (has_duplicates((Swizzle&) expr)) { |
| fErrors.error(expr.fPosition, |
| "cannot write to the same swizzle field more than once"); |
| } |
| this->markWrittenTo(*((Swizzle&) expr).fBase); |
| break; |
| case Expression::kIndex_Kind: |
| this->markWrittenTo(*((IndexExpression&) expr).fBase); |
| break; |
| default: |
| fErrors.error(expr.fPosition, "cannot assign to '" + expr.description() + "'"); |
| break; |
| } |
| } |
| |
| } |