clang-tools  10.0.0
InitVariablesCheck.cpp
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1 //===--- InitVariablesCheck.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 "InitVariablesCheck.h"
10 
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 
14 using namespace clang::ast_matchers;
15 
16 namespace clang {
17 namespace tidy {
18 namespace cppcoreguidelines {
19 
20 namespace {
21 AST_MATCHER(VarDecl, isLocalVarDecl) { return Node.isLocalVarDecl(); }
22 } // namespace
23 
24 InitVariablesCheck::InitVariablesCheck(StringRef Name,
25  ClangTidyContext *Context)
26  : ClangTidyCheck(Name, Context),
27  IncludeStyle(utils::IncludeSorter::parseIncludeStyle(
28  Options.getLocalOrGlobal("IncludeStyle", "llvm"))),
29  MathHeader(Options.get("MathHeader", "math.h")) {}
30 
31 void InitVariablesCheck::registerMatchers(MatchFinder *Finder) {
32  std::string BadDecl = "badDecl";
33  Finder->addMatcher(
34  varDecl(unless(hasInitializer(anything())), unless(isInstantiated()),
35  isLocalVarDecl(), unless(isStaticLocal()), isDefinition(),
36  optionally(hasParent(declStmt(hasParent(
37  cxxForRangeStmt(hasLoopVariable(varDecl().bind(BadDecl))))))),
38  unless(equalsBoundNode(BadDecl)))
39  .bind("vardecl"),
40  this);
41 }
42 
43 void InitVariablesCheck::registerPPCallbacks(const SourceManager &SM,
44  Preprocessor *PP,
45  Preprocessor *ModuleExpanderPP) {
46  IncludeInserter =
47  std::make_unique<utils::IncludeInserter>(SM, getLangOpts(), IncludeStyle);
48  PP->addPPCallbacks(IncludeInserter->CreatePPCallbacks());
49 }
50 
51 void InitVariablesCheck::check(const MatchFinder::MatchResult &Result) {
52  const auto *MatchedDecl = Result.Nodes.getNodeAs<VarDecl>("vardecl");
53  const ASTContext &Context = *Result.Context;
54  const SourceManager &Source = Context.getSourceManager();
55 
56  // We want to warn about cases where the type name
57  // comes from a macro like this:
58  //
59  // TYPENAME_FROM_MACRO var;
60  //
61  // but not if the entire declaration comes from
62  // one:
63  //
64  // DEFINE_SOME_VARIABLE();
65  //
66  // or if the definition comes from a macro like SWAP
67  // that uses an internal temporary variable.
68  //
69  // Thus check that the variable name does
70  // not come from a macro expansion.
71  if (MatchedDecl->getEndLoc().isMacroID())
72  return;
73 
74  QualType TypePtr = MatchedDecl->getType();
75  const char *InitializationString = nullptr;
76  bool AddMathInclude = false;
77 
78  if (TypePtr->isIntegerType())
79  InitializationString = " = 0";
80  else if (TypePtr->isFloatingType()) {
81  InitializationString = " = NAN";
82  AddMathInclude = true;
83  } else if (TypePtr->isAnyPointerType()) {
84  if (getLangOpts().CPlusPlus11)
85  InitializationString = " = nullptr";
86  else
87  InitializationString = " = NULL";
88  }
89 
90  if (InitializationString) {
91  auto Diagnostic =
92  diag(MatchedDecl->getLocation(), "variable %0 is not initialized")
93  << MatchedDecl
94  << FixItHint::CreateInsertion(
95  MatchedDecl->getLocation().getLocWithOffset(
96  MatchedDecl->getName().size()),
97  InitializationString);
98  if (AddMathInclude) {
99  auto IncludeHint = IncludeInserter->CreateIncludeInsertion(
100  Source.getFileID(MatchedDecl->getBeginLoc()), MathHeader, false);
101  if (IncludeHint)
102  Diagnostic << *IncludeHint;
103  }
104  }
105 }
106 
107 } // namespace cppcoreguidelines
108 } // namespace tidy
109 } // namespace clang
Base class for all clang-tidy checks.
const LangOptions & getLangOpts() const
Returns the language options from the context.
static constexpr llvm::StringLiteral Name
void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) override
Override this to register PPCallbacks in the preprocessor.
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check&#39;s name.