clang-tools-extra/clang-tidy/abseil/DurationConversionCastCheck.cpp

   1 //===--- DurationConversionCastCheck.cpp - clang-tidy ---------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "DurationConversionCastCheck.h"
  10 #include "DurationRewriter.h"
  11 #include "clang/AST/ASTContext.h"
  12 #include "clang/ASTMatchers/ASTMatchFinder.h"
  13 #include "clang/Tooling/FixIt.h"
  14 #include <optional>
  15
  16 using namespace clang::ast_matchers;
  17
  18 namespace clang::tidy::abseil {
  19
  20 void DurationConversionCastCheck::registerMatchers(MatchFinder *Finder) {
  21   auto CallMatcher = ignoringImpCasts(callExpr(
  22       callee(functionDecl(DurationConversionFunction()).bind("func_decl")),
  23       hasArgument(0, expr().bind("arg"))));
  24
  25   Finder->addMatcher(
  26       expr(anyOf(
  27           cxxStaticCastExpr(hasSourceExpression(CallMatcher)).bind("cast_expr"),
  28           cStyleCastExpr(hasSourceExpression(CallMatcher)).bind("cast_expr"),
  29           cxxFunctionalCastExpr(hasSourceExpression(CallMatcher))
  30               .bind("cast_expr"))),
  31       this);
  32 }
  33
  34 void DurationConversionCastCheck::check(
  35     const MatchFinder::MatchResult &Result) {
  36   const auto *MatchedCast =
  37       Result.Nodes.getNodeAs<ExplicitCastExpr>("cast_expr");
  38
  39   if (isInMacro(Result, MatchedCast))
  40     return;
  41
  42   const auto *FuncDecl = Result.Nodes.getNodeAs<FunctionDecl>("func_decl");
  43   const auto *Arg = Result.Nodes.getNodeAs<Expr>("arg");
  44   StringRef ConversionFuncName = FuncDecl->getName();
  45
  46   std::optional<DurationScale> Scale =
  47       getScaleForDurationInverse(ConversionFuncName);
  48   if (!Scale)
  49     return;
  50
  51   // Casting a double to an integer.
  52   if (MatchedCast->getTypeAsWritten()->isIntegerType() &&
  53       ConversionFuncName.contains("Double")) {
  54     llvm::StringRef NewFuncName = getDurationInverseForScale(*Scale).second;
  55
  56     diag(MatchedCast->getBeginLoc(),
  57          "duration should be converted directly to an integer rather than "
  58          "through a type cast")
  59         << FixItHint::CreateReplacement(
  60                MatchedCast->getSourceRange(),
  61                (llvm::Twine(NewFuncName.substr(2)) + "(" +
  62                 tooling::fixit::getText(*Arg, *Result.Context) + ")")
  63                    .str());
  64   }
  65
  66   // Casting an integer to a double.
  67   if (MatchedCast->getTypeAsWritten()->isRealFloatingType() &&
  68       ConversionFuncName.contains("Int64")) {
  69     llvm::StringRef NewFuncName = getDurationInverseForScale(*Scale).first;
  70
  71     diag(MatchedCast->getBeginLoc(), "duration should be converted directly to "
  72                                      "a floating-point number rather than "
  73                                      "through a type cast")
  74         << FixItHint::CreateReplacement(
  75                MatchedCast->getSourceRange(),
  76                (llvm::Twine(NewFuncName.substr(2)) + "(" +
  77                 tooling::fixit::getText(*Arg, *Result.Context) + ")")
  78                    .str());
  79   }
  80 }
  81
  82 } // namespace clang::tidy::abseil