clang-tools  9.0.0
AssertSideEffectCheck.cpp
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1 //===--- AssertSideEffectCheck.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 
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Frontend/CompilerInstance.h"
13 #include "clang/Lex/Lexer.h"
14 #include "llvm/ADT/SmallVector.h"
15 #include "llvm/ADT/StringRef.h"
16 #include "llvm/Support/Casting.h"
17 #include <algorithm>
18 #include <string>
19 
20 using namespace clang::ast_matchers;
21 
22 namespace clang {
23 namespace tidy {
24 namespace bugprone {
25 
26 namespace {
27 
28 AST_MATCHER_P(Expr, hasSideEffect, bool, CheckFunctionCalls) {
29  const Expr *E = &Node;
30 
31  if (const auto *Op = dyn_cast<UnaryOperator>(E)) {
32  UnaryOperator::Opcode OC = Op->getOpcode();
33  return OC == UO_PostInc || OC == UO_PostDec || OC == UO_PreInc ||
34  OC == UO_PreDec;
35  }
36 
37  if (const auto *Op = dyn_cast<BinaryOperator>(E)) {
38  return Op->isAssignmentOp();
39  }
40 
41  if (const auto *OpCallExpr = dyn_cast<CXXOperatorCallExpr>(E)) {
42  OverloadedOperatorKind OpKind = OpCallExpr->getOperator();
43  return OpKind == OO_Equal || OpKind == OO_PlusEqual ||
44  OpKind == OO_MinusEqual || OpKind == OO_StarEqual ||
45  OpKind == OO_SlashEqual || OpKind == OO_AmpEqual ||
46  OpKind == OO_PipeEqual || OpKind == OO_CaretEqual ||
47  OpKind == OO_LessLessEqual || OpKind == OO_GreaterGreaterEqual ||
48  OpKind == OO_PlusPlus || OpKind == OO_MinusMinus ||
49  OpKind == OO_PercentEqual || OpKind == OO_New ||
50  OpKind == OO_Delete || OpKind == OO_Array_New ||
51  OpKind == OO_Array_Delete;
52  }
53 
54  if (const auto *CExpr = dyn_cast<CallExpr>(E)) {
55  bool Result = CheckFunctionCalls;
56  if (const auto *FuncDecl = CExpr->getDirectCallee()) {
57  if (FuncDecl->getDeclName().isIdentifier() &&
58  FuncDecl->getName() == "__builtin_expect") // exceptions come here
59  Result = false;
60  else if (const auto *MethodDecl = dyn_cast<CXXMethodDecl>(FuncDecl))
61  Result &= !MethodDecl->isConst();
62  }
63  return Result;
64  }
65 
66  return isa<CXXNewExpr>(E) || isa<CXXDeleteExpr>(E) || isa<CXXThrowExpr>(E);
67 }
68 
69 } // namespace
70 
71 AssertSideEffectCheck::AssertSideEffectCheck(StringRef Name,
72  ClangTidyContext *Context)
73  : ClangTidyCheck(Name, Context),
74  CheckFunctionCalls(Options.get("CheckFunctionCalls", false)),
75  RawAssertList(Options.get("AssertMacros", "assert")) {
76  StringRef(RawAssertList).split(AssertMacros, ",", -1, false);
77 }
78 
79 // The options are explained in AssertSideEffectCheck.h.
81  Options.store(Opts, "CheckFunctionCalls", CheckFunctionCalls);
82  Options.store(Opts, "AssertMacros", RawAssertList);
83 }
84 
85 void AssertSideEffectCheck::registerMatchers(MatchFinder *Finder) {
86  auto DescendantWithSideEffect =
87  hasDescendant(expr(hasSideEffect(CheckFunctionCalls)));
88  auto ConditionWithSideEffect = hasCondition(DescendantWithSideEffect);
89  Finder->addMatcher(
90  stmt(
91  anyOf(conditionalOperator(ConditionWithSideEffect),
92  ifStmt(ConditionWithSideEffect),
93  unaryOperator(hasOperatorName("!"),
94  hasUnaryOperand(unaryOperator(
95  hasOperatorName("!"),
96  hasUnaryOperand(DescendantWithSideEffect))))))
97  .bind("condStmt"),
98  this);
99 }
100 
101 void AssertSideEffectCheck::check(const MatchFinder::MatchResult &Result) {
102  const SourceManager &SM = *Result.SourceManager;
103  const LangOptions LangOpts = getLangOpts();
104  SourceLocation Loc = Result.Nodes.getNodeAs<Stmt>("condStmt")->getBeginLoc();
105 
106  StringRef AssertMacroName;
107  while (Loc.isValid() && Loc.isMacroID()) {
108  StringRef MacroName = Lexer::getImmediateMacroName(Loc, SM, LangOpts);
109 
110  // Check if this macro is an assert.
111  if (llvm::is_contained(AssertMacros, MacroName)) {
112  AssertMacroName = MacroName;
113  break;
114  }
115  Loc = SM.getImmediateMacroCallerLoc(Loc);
116  }
117  if (AssertMacroName.empty())
118  return;
119 
120  diag(Loc, "found %0() with side effect") << AssertMacroName;
121 }
122 
123 } // namespace bugprone
124 } // namespace tidy
125 } // namespace clang
SourceLocation Loc
&#39;#&#39; location in the include directive
void storeOptions(ClangTidyOptions::OptionMap &Opts) override
Should store all options supported by this check with their current values or default values for opti...
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
Base class for all clang-tidy checks.
const LangOptions & getLangOpts() const
Returns the language options from the context.
void store(ClangTidyOptions::OptionMap &Options, StringRef LocalName, StringRef Value) const
Stores an option with the check-local name LocalName with string value Value to Options.
static constexpr llvm::StringLiteral Name
std::map< std::string, std::string > OptionMap
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
Definition: Rename.cpp:36
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check&#39;s name.
AST_MATCHER_P(CXXMethodDecl, hasCanonicalDecl, ast_matchers::internal::Matcher< CXXMethodDecl >, InnerMatcher)