clang-tools-extra/clang-tidy/bugprone/NondeterministicPointerIterationOrderCheck.cpp

   1 //===----- NondeterministicPointerIterationOrderCheck.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 "NondeterministicPointerIterationOrderCheck.h"
  10 #include "clang/AST/ASTContext.h"
  11 #include "clang/Lex/Lexer.h"
  12
  13 using namespace clang::ast_matchers;
  14
  15 namespace clang::tidy::bugprone {
  16
  17 void NondeterministicPointerIterationOrderCheck::registerMatchers(
  18     MatchFinder *Finder) {
  19
  20   auto LoopVariable = varDecl(hasType(
  21       qualType(hasCanonicalType(anyOf(referenceType(), pointerType())))));
  22
  23   auto RangeInit = declRefExpr(to(varDecl(
  24       hasType(recordDecl(hasAnyName("std::unordered_set", "std::unordered_map",
  25                                     "std::unordered_multiset",
  26                                     "std::unordered_multimap"))
  27                   .bind("recorddecl")))));
  28
  29   Finder->addMatcher(cxxForRangeStmt(hasLoopVariable(LoopVariable),
  30                                      hasRangeInit(RangeInit.bind("rangeinit")))
  31                          .bind("cxxForRangeStmt"),
  32                      this);
  33
  34   auto SortFuncM = callee(functionDecl(hasAnyName(
  35       "std::is_sorted", "std::nth_element", "std::sort", "std::partial_sort",
  36       "std::partition", "std::stable_partition", "std::stable_sort")));
  37
  38   auto IteratesPointerEltsM = hasArgument(
  39       0,
  40       cxxMemberCallExpr(on(hasType(cxxRecordDecl(has(fieldDecl(hasType(qualType(
  41           hasCanonicalType(pointsTo(hasCanonicalType(pointerType()))))))))))));
  42
  43   Finder->addMatcher(
  44       callExpr(allOf(SortFuncM, IteratesPointerEltsM)).bind("sortsemantic"),
  45       this);
  46 }
  47
  48 void NondeterministicPointerIterationOrderCheck::check(
  49     const MatchFinder::MatchResult &Result) {
  50   const auto *ForRangePointers =
  51       Result.Nodes.getNodeAs<CXXForRangeStmt>("cxxForRangeStmt");
  52
  53   if ((ForRangePointers) && !(ForRangePointers->getBeginLoc().isMacroID())) {
  54     const auto *RangeInit = Result.Nodes.getNodeAs<Stmt>("rangeinit");
  55     if (const auto *ClassTemplate =
  56             Result.Nodes.getNodeAs<ClassTemplateSpecializationDecl>(
  57                 "recorddecl")) {
  58       const TemplateArgumentList &TemplateArgs =
  59           ClassTemplate->getTemplateArgs();
  60       const bool IsAlgoArgPointer =
  61           TemplateArgs[0].getAsType()->isPointerType();
  62
  63       if (IsAlgoArgPointer) {
  64         SourceRange R = RangeInit->getSourceRange();
  65         diag(R.getBegin(), "iteration of pointers is nondeterministic") << R;
  66       }
  67     }
  68     return;
  69   }
  70   const auto *SortPointers = Result.Nodes.getNodeAs<Stmt>("sortsemantic");
  71
  72   if ((SortPointers) && !(SortPointers->getBeginLoc().isMacroID())) {
  73     SourceRange R = SortPointers->getSourceRange();
  74     diag(R.getBegin(), "sorting pointers is nondeterministic") << R;
  75   }
  76 }
  77
  78 } // namespace clang::tidy::bugprone