| /* |
| * Copyright (C) 2019 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS |
| * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
| * THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "config.h" |
| #include "WHLSLStatementBehaviorChecker.h" |
| |
| #if ENABLE(WEBGPU) |
| |
| #include "WHLSLBlock.h" |
| #include "WHLSLBreak.h" |
| #include "WHLSLContinue.h" |
| #include "WHLSLDoWhileLoop.h" |
| #include "WHLSLEffectfulExpressionStatement.h" |
| #include "WHLSLFallthrough.h" |
| #include "WHLSLForLoop.h" |
| #include "WHLSLIfStatement.h" |
| #include "WHLSLInferTypes.h" |
| #include "WHLSLProgram.h" |
| #include "WHLSLReturn.h" |
| #include "WHLSLSwitchCase.h" |
| #include "WHLSLSwitchStatement.h" |
| #include "WHLSLVariableDeclarationsStatement.h" |
| #include "WHLSLVisitor.h" |
| #include "WHLSLWhileLoop.h" |
| #include <cstdint> |
| #include <wtf/OptionSet.h> |
| #include <wtf/Vector.h> |
| |
| namespace WebCore { |
| |
| namespace WHLSL { |
| |
| class StatementBehaviorChecker : public Visitor { |
| public: |
| enum class Behavior : uint8_t { |
| Return = 1 << 0, |
| Break = 1 << 1, |
| Continue = 1 << 2, |
| Fallthrough = 1 << 3, |
| Nothing = 1 << 4 |
| }; |
| |
| OptionSet<Behavior> takeFunctionBehavior() |
| { |
| ASSERT(m_stack.size() == 1); |
| return m_stack.takeLast(); |
| } |
| |
| private: |
| void visit(AST::Break&) override |
| { |
| m_stack.append({ Behavior::Break }); |
| } |
| |
| void visit(AST::Fallthrough&) override |
| { |
| m_stack.append({ Behavior::Fallthrough }); |
| } |
| |
| void visit(AST::Continue&) override |
| { |
| m_stack.append({ Behavior::Continue }); |
| } |
| |
| void visit(AST::Return&) override |
| { |
| m_stack.append({ Behavior::Return }); |
| } |
| |
| void visit(AST::DoWhileLoop& doWhileLoop) override |
| { |
| checkErrorAndVisit(doWhileLoop.body()); |
| if (hasError()) |
| return; |
| auto b = m_stack.takeLast(); |
| b.remove(Behavior::Break); |
| b.remove(Behavior::Continue); |
| b.add(Behavior::Nothing); |
| m_stack.append(b); |
| } |
| |
| void visit(AST::ForLoop& forLoop) override |
| { |
| // The initialization always has a behavior of Nothing, which we already add unconditionally below, |
| // so we can just ignore the initialization. |
| |
| checkErrorAndVisit(forLoop.body()); |
| if (hasError()) |
| return; |
| auto b = m_stack.takeLast(); |
| b.remove(Behavior::Break); |
| b.remove(Behavior::Continue); |
| b.add(Behavior::Nothing); |
| m_stack.append(b); |
| } |
| |
| void visit(AST::WhileLoop& whileLoop) override |
| { |
| checkErrorAndVisit(whileLoop.body()); |
| if (hasError()) |
| return; |
| auto b = m_stack.takeLast(); |
| b.remove(Behavior::Break); |
| b.remove(Behavior::Continue); |
| b.add(Behavior::Nothing); |
| m_stack.append(b); |
| } |
| |
| void visit(AST::SwitchCase& switchCase) override |
| { |
| Visitor::visit(switchCase); |
| } |
| |
| void visit(AST::SwitchStatement& switchStatement) override |
| { |
| if (switchStatement.switchCases().isEmpty()) { |
| m_stack.append({ Behavior::Nothing }); |
| return; |
| } |
| |
| OptionSet<Behavior> reduction = { }; |
| for (auto& switchCase : switchStatement.switchCases()) { |
| checkErrorAndVisit(switchCase); |
| if (hasError()) |
| return; |
| auto b = m_stack.takeLast(); |
| reduction = reduction | b; |
| } |
| if (reduction.contains(Behavior::Nothing)) { |
| setError(Error("Switch statement must end in a break/fallthrough/return", switchStatement.codeLocation())); |
| return; |
| } |
| reduction.remove(Behavior::Break); |
| reduction.remove(Behavior::Fallthrough); |
| reduction.add(Behavior::Nothing); |
| m_stack.append(reduction); |
| } |
| |
| void visit(AST::IfStatement& ifStatement) override |
| { |
| checkErrorAndVisit(ifStatement.body()); |
| if (hasError()) |
| return; |
| auto b = m_stack.takeLast(); |
| OptionSet<Behavior> bPrime; |
| if (ifStatement.elseBody()) { |
| checkErrorAndVisit(*ifStatement.elseBody()); |
| if (hasError()) |
| return; |
| bPrime = m_stack.takeLast(); |
| } else |
| bPrime = { Behavior::Nothing }; |
| m_stack.append(b | bPrime); |
| } |
| |
| void visit(AST::EffectfulExpressionStatement&) override |
| { |
| m_stack.append({ Behavior::Nothing }); |
| } |
| |
| void visit(AST::Block& block) override |
| { |
| if (block.statements().isEmpty()) { |
| m_stack.append({ Behavior::Nothing }); |
| return; |
| } |
| |
| OptionSet<Behavior> reduction = { }; |
| for (size_t i = 0; i < block.statements().size() - 1; ++i) { |
| checkErrorAndVisit(block.statements()[i]); |
| if (hasError()) |
| return; |
| auto b = m_stack.takeLast(); |
| if (!b.contains(Behavior::Nothing)) { |
| setError(Error("Statement inside an inner block must be reachable.", block.statements()[i]->codeLocation())); |
| return; |
| } |
| b.remove(Behavior::Nothing); |
| if (b.contains(Behavior::Fallthrough)) { |
| setError(Error("Fallthrough must be the last statement in a block.", block.statements()[i]->codeLocation())); |
| return; |
| } |
| reduction = reduction | b; |
| } |
| checkErrorAndVisit(block.statements()[block.statements().size() - 1]); |
| if (hasError()) |
| return; |
| auto b = m_stack.takeLast(); |
| m_stack.append(reduction | b); |
| } |
| |
| void visit(AST::VariableDeclarationsStatement&) override |
| { |
| m_stack.append({ Behavior::Nothing }); |
| } |
| |
| Vector<OptionSet<Behavior>> m_stack; |
| }; |
| |
| Expected<void, Error> checkStatementBehavior(Program& program) |
| { |
| StatementBehaviorChecker statementBehaviorChecker; |
| for (auto& functionDefinition : program.functionDefinitions()) { |
| statementBehaviorChecker.Visitor::visit(functionDefinition); |
| if (statementBehaviorChecker.hasError()) |
| return statementBehaviorChecker.result(); |
| auto behavior = statementBehaviorChecker.takeFunctionBehavior(); |
| if (matches(functionDefinition->type(), program.intrinsics().voidType())) { |
| behavior.remove(StatementBehaviorChecker::Behavior::Return); |
| behavior.remove(StatementBehaviorChecker::Behavior::Nothing); |
| if (behavior != OptionSet<StatementBehaviorChecker::Behavior>()) |
| return makeUnexpected(Error("Cannot end a void function with a break, continue, or fallthrough.")); |
| } else { |
| if (behavior != StatementBehaviorChecker::Behavior::Return) |
| return makeUnexpected(Error("Non-void functions must return a value on all code paths.")); |
| } |
| } |
| return { }; |
| } |
| |
| } // namespace WHLSL |
| |
| } // namespace WebCore |
| |
| #endif // ENABLE(WEBGPU) |