clang-tools  3.8.0
AssertSideEffectCheck.cpp
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1 //===--- AssertSideEffectCheck.cpp - clang-tidy ---------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "AssertSideEffectCheck.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/Frontend/CompilerInstance.h"
14 #include "clang/Lex/Lexer.h"
15 #include "llvm/ADT/SmallVector.h"
16 #include "llvm/ADT/StringRef.h"
17 #include "llvm/Support/Casting.h"
18 #include <algorithm>
19 #include <string>
20 
21 using namespace clang::ast_matchers;
22 
23 namespace clang {
24 namespace {
25 
26 AST_MATCHER_P(Expr, hasSideEffect, bool, CheckFunctionCalls) {
27  const Expr *E = &Node;
28 
29  if (const auto *Op = dyn_cast<UnaryOperator>(E)) {
30  UnaryOperator::Opcode OC = Op->getOpcode();
31  return OC == UO_PostInc || OC == UO_PostDec || OC == UO_PreInc ||
32  OC == UO_PreDec;
33  }
34 
35  if (const auto *Op = dyn_cast<BinaryOperator>(E)) {
36  return Op->isAssignmentOp();
37  }
38 
39  if (const auto *OpCallExpr = dyn_cast<CXXOperatorCallExpr>(E)) {
40  OverloadedOperatorKind OpKind = OpCallExpr->getOperator();
41  return OpKind == OO_Equal || OpKind == OO_PlusEqual ||
42  OpKind == OO_MinusEqual || OpKind == OO_StarEqual ||
43  OpKind == OO_SlashEqual || OpKind == OO_AmpEqual ||
44  OpKind == OO_PipeEqual || OpKind == OO_CaretEqual ||
45  OpKind == OO_LessLessEqual || OpKind == OO_GreaterGreaterEqual ||
46  OpKind == OO_PlusPlus || OpKind == OO_MinusMinus ||
47  OpKind == OO_PercentEqual || OpKind == OO_New ||
48  OpKind == OO_Delete || OpKind == OO_Array_New ||
49  OpKind == OO_Array_Delete;
50  }
51 
52  if (const auto *CExpr = dyn_cast<CallExpr>(E)) {
53  bool Result = CheckFunctionCalls;
54  if (const auto *FuncDecl = CExpr->getDirectCallee()) {
55  if (FuncDecl->getDeclName().isIdentifier() &&
56  FuncDecl->getName() == "__builtin_expect") // exceptions come here
57  Result = false;
58  else if (const auto *MethodDecl = dyn_cast<CXXMethodDecl>(FuncDecl))
59  Result &= !MethodDecl->isConst();
60  }
61  return Result;
62  }
63 
64  return isa<CXXNewExpr>(E) || isa<CXXDeleteExpr>(E) || isa<CXXThrowExpr>(E);
65 }
66 
67 } // namespace
68 
69 namespace tidy {
70 
71 AssertSideEffectCheck::AssertSideEffectCheck(StringRef Name,
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 
86  auto ConditionWithSideEffect =
87  hasCondition(hasDescendant(expr(hasSideEffect(CheckFunctionCalls))));
88  Finder->addMatcher(
89  stmt(anyOf(conditionalOperator(ConditionWithSideEffect),
90  ifStmt(ConditionWithSideEffect))).bind("condStmt"),
91  this);
92 }
93 
94 void AssertSideEffectCheck::check(const MatchFinder::MatchResult &Result) {
95  const SourceManager &SM = *Result.SourceManager;
96  const LangOptions LangOpts = Result.Context->getLangOpts();
97  SourceLocation Loc = Result.Nodes.getNodeAs<Stmt>("condStmt")->getLocStart();
98 
99  StringRef AssertMacroName;
100  while (Loc.isValid() && Loc.isMacroID()) {
101  StringRef MacroName = Lexer::getImmediateMacroName(Loc, SM, LangOpts);
102 
103  // Check if this macro is an assert.
104  if (std::find(AssertMacros.begin(), AssertMacros.end(), MacroName) !=
105  AssertMacros.end()) {
106  AssertMacroName = MacroName;
107  break;
108  }
109  Loc = SM.getImmediateMacroCallerLoc(Loc);
110  }
111  if (AssertMacroName.empty())
112  return;
113 
114  diag(Loc, "found %0() with side effect") << AssertMacroName;
115 }
116 
117 } // namespace tidy
118 } // namespace clang
SourceLocation Loc
'#' location in the include directive
LangOptions LangOpts
Definition: ClangTidy.cpp:168
StringHandle Name
std::unique_ptr< ast_matchers::MatchFinder > Finder
Definition: ClangTidy.cpp:188
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
Base class for all clang-tidy checks.
Definition: ClangTidy.h:102
void storeOptions(ClangTidyOptions::OptionMap &Opts) override
Should store all options supported by this check with their current values or default values for opti...
SourceManager & SM
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register ASTMatchers with Finder.
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.
Definition: ClangTidy.cpp:344
std::map< std::string, std::string > OptionMap
AST_MATCHER_P(CXXForRangeStmt, hasRangeBeginEndStmt, ast_matchers::internal::Matcher< DeclStmt >, InnerMatcher)
ClangTidyContext & Context
Definition: ClangTidy.cpp:93
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check's name.
Definition: ClangTidy.cpp:323
const NamedDecl * Result
Definition: USRFinder.cpp:121