clang-tools  8.0.0
IntegerTypesCheck.cpp
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1 //===--- IntegerTypesCheck.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 "IntegerTypesCheck.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/ASTMatchers/ASTMatchers.h"
14 #include "clang/Basic/AttrKinds.h"
15 #include "clang/Basic/CharInfo.h"
16 #include "clang/Basic/IdentifierTable.h"
17 #include "clang/Basic/TargetInfo.h"
18 #include "clang/Lex/Lexer.h"
19 
20 namespace clang {
21 
22 using namespace ast_matchers;
23 
24 static Token getTokenAtLoc(SourceLocation Loc,
25  const MatchFinder::MatchResult &MatchResult,
26  IdentifierTable &IdentTable) {
27  Token Tok;
28  if (Lexer::getRawToken(Loc, Tok, *MatchResult.SourceManager,
29  MatchResult.Context->getLangOpts(), false))
30  return Tok;
31 
32  if (Tok.is(tok::raw_identifier)) {
33  IdentifierInfo &Info = IdentTable.get(Tok.getRawIdentifier());
34  Tok.setIdentifierInfo(&Info);
35  Tok.setKind(Info.getTokenID());
36  }
37  return Tok;
38 }
39 
40 namespace tidy {
41 namespace google {
42 namespace runtime {
43 
44 IntegerTypesCheck::IntegerTypesCheck(StringRef Name, ClangTidyContext *Context)
45  : ClangTidyCheck(Name, Context),
46  UnsignedTypePrefix(Options.get("UnsignedTypePrefix", "uint")),
47  SignedTypePrefix(Options.get("SignedTypePrefix", "int")),
48  TypeSuffix(Options.get("TypeSuffix", "")) {}
49 
51  Options.store(Opts, "UnsignedTypePrefix", UnsignedTypePrefix);
52  Options.store(Opts, "SignedTypePrefix", SignedTypePrefix);
53  Options.store(Opts, "TypeSuffix", TypeSuffix);
54 }
55 
56 void IntegerTypesCheck::registerMatchers(MatchFinder *Finder) {
57  // Find all TypeLocs. The relevant Style Guide rule only applies to C++.
58  if (!getLangOpts().CPlusPlus)
59  return;
60  // Match any integer types, unless they are passed to a printf-based API:
61  //
62  // http://google.github.io/styleguide/cppguide.html#64-bit_Portability
63  // "Where possible, avoid passing arguments of types specified by
64  // bitwidth typedefs to printf-based APIs."
65  Finder->addMatcher(typeLoc(loc(isInteger()),
66  unless(hasAncestor(callExpr(
67  callee(functionDecl(hasAttr(attr::Format)))))))
68  .bind("tl"),
69  this);
70  IdentTable = llvm::make_unique<IdentifierTable>(getLangOpts());
71 }
72 
73 void IntegerTypesCheck::check(const MatchFinder::MatchResult &Result) {
74  auto TL = *Result.Nodes.getNodeAs<TypeLoc>("tl");
75  SourceLocation Loc = TL.getBeginLoc();
76 
77  if (Loc.isInvalid() || Loc.isMacroID())
78  return;
79 
80  // Look through qualification.
81  if (auto QualLoc = TL.getAs<QualifiedTypeLoc>())
82  TL = QualLoc.getUnqualifiedLoc();
83 
84  auto BuiltinLoc = TL.getAs<BuiltinTypeLoc>();
85  if (!BuiltinLoc)
86  return;
87 
88  Token Tok = getTokenAtLoc(Loc, Result, *IdentTable);
89  // Ensure the location actually points to one of the builting integral type
90  // names we're interested in. Otherwise, we might be getting this match from
91  // implicit code (e.g. an implicit assignment operator of a class containing
92  // an array of non-POD types).
93  if (!Tok.isOneOf(tok::kw_short, tok::kw_long, tok::kw_unsigned,
94  tok::kw_signed))
95  return;
96 
97  bool IsSigned;
98  unsigned Width;
99  const TargetInfo &TargetInfo = Result.Context->getTargetInfo();
100 
101  // Look for uses of short, long, long long and their unsigned versions.
102  switch (BuiltinLoc.getTypePtr()->getKind()) {
103  case BuiltinType::Short:
104  Width = TargetInfo.getShortWidth();
105  IsSigned = true;
106  break;
107  case BuiltinType::Long:
108  Width = TargetInfo.getLongWidth();
109  IsSigned = true;
110  break;
111  case BuiltinType::LongLong:
112  Width = TargetInfo.getLongLongWidth();
113  IsSigned = true;
114  break;
115  case BuiltinType::UShort:
116  Width = TargetInfo.getShortWidth();
117  IsSigned = false;
118  break;
119  case BuiltinType::ULong:
120  Width = TargetInfo.getLongWidth();
121  IsSigned = false;
122  break;
123  case BuiltinType::ULongLong:
124  Width = TargetInfo.getLongLongWidth();
125  IsSigned = false;
126  break;
127  default:
128  return;
129  }
130 
131  // We allow "unsigned short port" as that's reasonably common and required by
132  // the sockets API.
133  const StringRef Port = "unsigned short port";
134  const char *Data = Result.SourceManager->getCharacterData(Loc);
135  if (!std::strncmp(Data, Port.data(), Port.size()) &&
136  !isIdentifierBody(Data[Port.size()]))
137  return;
138 
139  std::string Replacement =
140  ((IsSigned ? SignedTypePrefix : UnsignedTypePrefix) + Twine(Width) +
141  TypeSuffix)
142  .str();
143 
144  // We don't add a fix-it as changing the type can easily break code,
145  // e.g. when a function requires a 'long' argument on all platforms.
146  // QualTypes are printed with implicit quotes.
147  diag(Loc, "consider replacing %0 with '%1'") << BuiltinLoc.getType()
148  << Replacement;
149 }
150 
151 } // namespace runtime
152 } // namespace google
153 } // namespace tidy
154 } // namespace clang
SourceLocation Loc
&#39;#&#39; location in the include directive
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:473
LangOptions getLangOpts() const
Returns the language options from the context.
Definition: ClangTidy.h:187
Base class for all clang-tidy checks.
Definition: ClangTidy.h:127
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
static constexpr llvm::StringLiteral Name
std::map< std::string, std::string > OptionMap
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
FunctionInfo Info
===– 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.
void storeOptions(ClangTidyOptions::OptionMap &Options) override
Should store all options supported by this check with their current values or default values for opti...
static Token getTokenAtLoc(SourceLocation Loc, const MatchFinder::MatchResult &MatchResult, IdentifierTable &IdentTable)
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check&#39;s name.
Definition: ClangTidy.cpp:438