| //===--- DurationFactoryScaleCheck.cpp - clang-tidy -----------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "DurationFactoryScaleCheck.h" |
| #include "DurationRewriter.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/ASTMatchers/ASTMatchFinder.h" |
| #include "clang/Tooling/FixIt.h" |
| |
| using namespace clang::ast_matchers; |
| |
| namespace clang { |
| namespace tidy { |
| namespace abseil { |
| |
| // Given the name of a duration factory function, return the appropriate |
| // `DurationScale` for that factory. If no factory can be found for |
| // `FactoryName`, return `None`. |
| static llvm::Optional<DurationScale> |
| getScaleForFactory(llvm::StringRef FactoryName) { |
| static const std::unordered_map<std::string, DurationScale> ScaleMap( |
| {{"Nanoseconds", DurationScale::Nanoseconds}, |
| {"Microseconds", DurationScale::Microseconds}, |
| {"Milliseconds", DurationScale::Milliseconds}, |
| {"Seconds", DurationScale::Seconds}, |
| {"Minutes", DurationScale::Minutes}, |
| {"Hours", DurationScale::Hours}}); |
| |
| auto ScaleIter = ScaleMap.find(FactoryName); |
| if (ScaleIter == ScaleMap.end()) |
| return llvm::None; |
| |
| return ScaleIter->second; |
| } |
| |
| // Given either an integer or float literal, return its value. |
| // One and only one of `IntLit` and `FloatLit` should be provided. |
| static double GetValue(const IntegerLiteral *IntLit, |
| const FloatingLiteral *FloatLit) { |
| if (IntLit) |
| return IntLit->getValue().getLimitedValue(); |
| |
| assert(FloatLit != nullptr && "Neither IntLit nor FloatLit set"); |
| return FloatLit->getValueAsApproximateDouble(); |
| } |
| |
| // Given the scale of a duration and a `Multiplier`, determine if `Multiplier` |
| // would produce a new scale. If so, return a tuple containing the new scale |
| // and a suitable Multipler for that scale, otherwise `None`. |
| static llvm::Optional<std::tuple<DurationScale, double>> |
| GetNewScaleSingleStep(DurationScale OldScale, double Multiplier) { |
| switch (OldScale) { |
| case DurationScale::Hours: |
| if (Multiplier <= 1.0 / 60.0) |
| return std::make_tuple(DurationScale::Minutes, Multiplier * 60.0); |
| break; |
| |
| case DurationScale::Minutes: |
| if (Multiplier >= 60.0) |
| return std::make_tuple(DurationScale::Hours, Multiplier / 60.0); |
| if (Multiplier <= 1.0 / 60.0) |
| return std::make_tuple(DurationScale::Seconds, Multiplier * 60.0); |
| break; |
| |
| case DurationScale::Seconds: |
| if (Multiplier >= 60.0) |
| return std::make_tuple(DurationScale::Minutes, Multiplier / 60.0); |
| if (Multiplier <= 1e-3) |
| return std::make_tuple(DurationScale::Milliseconds, Multiplier * 1e3); |
| break; |
| |
| case DurationScale::Milliseconds: |
| if (Multiplier >= 1e3) |
| return std::make_tuple(DurationScale::Seconds, Multiplier / 1e3); |
| if (Multiplier <= 1e-3) |
| return std::make_tuple(DurationScale::Microseconds, Multiplier * 1e3); |
| break; |
| |
| case DurationScale::Microseconds: |
| if (Multiplier >= 1e3) |
| return std::make_tuple(DurationScale::Milliseconds, Multiplier / 1e3); |
| if (Multiplier <= 1e-3) |
| return std::make_tuple(DurationScale::Nanoseconds, Multiplier * 1e-3); |
| break; |
| |
| case DurationScale::Nanoseconds: |
| if (Multiplier >= 1e3) |
| return std::make_tuple(DurationScale::Microseconds, Multiplier / 1e3); |
| break; |
| } |
| |
| return llvm::None; |
| } |
| |
| // Given the scale of a duration and a `Multiplier`, determine if `Multiplier` |
| // would produce a new scale. If so, return it, otherwise `None`. |
| static llvm::Optional<DurationScale> GetNewScale(DurationScale OldScale, |
| double Multiplier) { |
| while (Multiplier != 1.0) { |
| llvm::Optional<std::tuple<DurationScale, double>> result = |
| GetNewScaleSingleStep(OldScale, Multiplier); |
| if (!result) |
| break; |
| if (std::get<1>(*result) == 1.0) |
| return std::get<0>(*result); |
| Multiplier = std::get<1>(*result); |
| OldScale = std::get<0>(*result); |
| } |
| |
| return llvm::None; |
| } |
| |
| void DurationFactoryScaleCheck::registerMatchers(MatchFinder *Finder) { |
| Finder->addMatcher( |
| callExpr( |
| callee(functionDecl(DurationFactoryFunction()).bind("call_decl")), |
| hasArgument( |
| 0, |
| ignoringImpCasts(anyOf( |
| cxxFunctionalCastExpr( |
| hasDestinationType( |
| anyOf(isInteger(), realFloatingPointType())), |
| hasSourceExpression(initListExpr())), |
| integerLiteral(equals(0)), floatLiteral(equals(0.0)), |
| binaryOperator(hasOperatorName("*"), |
| hasEitherOperand(ignoringImpCasts( |
| anyOf(integerLiteral(), floatLiteral())))) |
| .bind("mult_binop"), |
| binaryOperator(hasOperatorName("/"), hasRHS(floatLiteral())) |
| .bind("div_binop"))))) |
| .bind("call"), |
| this); |
| } |
| |
| void DurationFactoryScaleCheck::check(const MatchFinder::MatchResult &Result) { |
| const auto *Call = Result.Nodes.getNodeAs<CallExpr>("call"); |
| |
| // Don't try to replace things inside of macro definitions. |
| if (Call->getExprLoc().isMacroID()) |
| return; |
| |
| const Expr *Arg = Call->getArg(0)->IgnoreParenImpCasts(); |
| // Arguments which are macros are ignored. |
| if (Arg->getBeginLoc().isMacroID()) |
| return; |
| |
| // We first handle the cases of literal zero (both float and integer). |
| if (IsLiteralZero(Result, *Arg)) { |
| diag(Call->getBeginLoc(), |
| "use ZeroDuration() for zero-length time intervals") |
| << FixItHint::CreateReplacement(Call->getSourceRange(), |
| "absl::ZeroDuration()"); |
| return; |
| } |
| |
| const auto *CallDecl = Result.Nodes.getNodeAs<FunctionDecl>("call_decl"); |
| llvm::Optional<DurationScale> MaybeScale = |
| getScaleForFactory(CallDecl->getName()); |
| if (!MaybeScale) |
| return; |
| |
| DurationScale Scale = *MaybeScale; |
| const Expr *Remainder; |
| llvm::Optional<DurationScale> NewScale; |
| |
| // We next handle the cases of multiplication and division. |
| if (const auto *MultBinOp = |
| Result.Nodes.getNodeAs<BinaryOperator>("mult_binop")) { |
| // For multiplication, we need to look at both operands, and consider the |
| // cases where a user is multiplying by something such as 1e-3. |
| |
| // First check the LHS |
| const auto *IntLit = llvm::dyn_cast<IntegerLiteral>(MultBinOp->getLHS()); |
| const auto *FloatLit = llvm::dyn_cast<FloatingLiteral>(MultBinOp->getLHS()); |
| if (IntLit || FloatLit) { |
| NewScale = GetNewScale(Scale, GetValue(IntLit, FloatLit)); |
| if (NewScale) |
| Remainder = MultBinOp->getRHS(); |
| } |
| |
| // If we weren't able to scale based on the LHS, check the RHS |
| if (!NewScale) { |
| IntLit = llvm::dyn_cast<IntegerLiteral>(MultBinOp->getRHS()); |
| FloatLit = llvm::dyn_cast<FloatingLiteral>(MultBinOp->getRHS()); |
| if (IntLit || FloatLit) { |
| NewScale = GetNewScale(Scale, GetValue(IntLit, FloatLit)); |
| if (NewScale) |
| Remainder = MultBinOp->getLHS(); |
| } |
| } |
| } else if (const auto *DivBinOp = |
| Result.Nodes.getNodeAs<BinaryOperator>("div_binop")) { |
| // We next handle division. |
| // For division, we only check the RHS. |
| const auto *FloatLit = llvm::dyn_cast<FloatingLiteral>(DivBinOp->getRHS()); |
| |
| llvm::Optional<DurationScale> NewScale = |
| GetNewScale(Scale, 1.0 / FloatLit->getValueAsApproximateDouble()); |
| if (NewScale) { |
| const Expr *Remainder = DivBinOp->getLHS(); |
| |
| // We've found an appropriate scaling factor and the new scale, so output |
| // the relevant fix. |
| diag(Call->getBeginLoc(), "internal duration scaling can be removed") |
| << FixItHint::CreateReplacement( |
| Call->getSourceRange(), |
| (llvm::Twine(getDurationFactoryForScale(*NewScale)) + "(" + |
| tooling::fixit::getText(*Remainder, *Result.Context) + ")") |
| .str()); |
| } |
| } |
| |
| if (NewScale) { |
| assert(Remainder && "No remainder found"); |
| // We've found an appropriate scaling factor and the new scale, so output |
| // the relevant fix. |
| diag(Call->getBeginLoc(), "internal duration scaling can be removed") |
| << FixItHint::CreateReplacement( |
| Call->getSourceRange(), |
| (llvm::Twine(getDurationFactoryForScale(*NewScale)) + "(" + |
| tooling::fixit::getText(*Remainder, *Result.Context) + ")") |
| .str()); |
| } |
| return; |
| } |
| |
| } // namespace abseil |
| } // namespace tidy |
| } // namespace clang |
