clang-tools  10.0.0git
IntegerTypesCheck.cpp
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1 //===--- IntegerTypesCheck.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 "IntegerTypesCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/ASTMatchers/ASTMatchers.h"
13 #include "clang/Basic/AttrKinds.h"
14 #include "clang/Basic/CharInfo.h"
15 #include "clang/Basic/IdentifierTable.h"
16 #include "clang/Basic/TargetInfo.h"
17 #include "clang/Lex/Lexer.h"
18 
19 namespace clang {
20 
21 using namespace ast_matchers;
22 
23 static Token getTokenAtLoc(SourceLocation Loc,
24  const MatchFinder::MatchResult &MatchResult,
25  IdentifierTable &IdentTable) {
26  Token Tok;
27  if (Lexer::getRawToken(Loc, Tok, *MatchResult.SourceManager,
28  MatchResult.Context->getLangOpts(), false))
29  return Tok;
30 
31  if (Tok.is(tok::raw_identifier)) {
32  IdentifierInfo &Info = IdentTable.get(Tok.getRawIdentifier());
33  Tok.setIdentifierInfo(&Info);
34  Tok.setKind(Info.getTokenID());
35  }
36  return Tok;
37 }
38 
39 namespace tidy {
40 namespace google {
41 namespace runtime {
42 
43 IntegerTypesCheck::IntegerTypesCheck(StringRef Name, ClangTidyContext *Context)
44  : ClangTidyCheck(Name, Context),
45  UnsignedTypePrefix(Options.get("UnsignedTypePrefix", "uint")),
46  SignedTypePrefix(Options.get("SignedTypePrefix", "int")),
47  TypeSuffix(Options.get("TypeSuffix", "")) {}
48 
50  Options.store(Opts, "UnsignedTypePrefix", UnsignedTypePrefix);
51  Options.store(Opts, "SignedTypePrefix", SignedTypePrefix);
52  Options.store(Opts, "TypeSuffix", TypeSuffix);
53 }
54 
55 void IntegerTypesCheck::registerMatchers(MatchFinder *Finder) {
56  // Find all TypeLocs. The relevant Style Guide rule only applies to C++.
57  // This check is also not applied in Objective-C++ sources as Objective-C
58  // often uses built-in integer types other than `int`.
59  if (!getLangOpts().CPlusPlus || getLangOpts().ObjC)
60  return;
61  // Match any integer types, unless they are passed to a printf-based API:
62  //
63  // http://google.github.io/styleguide/cppguide.html#64-bit_Portability
64  // "Where possible, avoid passing arguments of types specified by
65  // bitwidth typedefs to printf-based APIs."
66  Finder->addMatcher(typeLoc(loc(isInteger()),
67  unless(hasAncestor(callExpr(
68  callee(functionDecl(hasAttr(attr::Format)))))))
69  .bind("tl"),
70  this);
71  IdentTable = std::make_unique<IdentifierTable>(getLangOpts());
72 }
73 
74 void IntegerTypesCheck::check(const MatchFinder::MatchResult &Result) {
75  auto TL = *Result.Nodes.getNodeAs<TypeLoc>("tl");
76  SourceLocation Loc = TL.getBeginLoc();
77 
78  if (Loc.isInvalid() || Loc.isMacroID())
79  return;
80 
81  // Look through qualification.
82  if (auto QualLoc = TL.getAs<QualifiedTypeLoc>())
83  TL = QualLoc.getUnqualifiedLoc();
84 
85  auto BuiltinLoc = TL.getAs<BuiltinTypeLoc>();
86  if (!BuiltinLoc)
87  return;
88 
89  Token Tok = getTokenAtLoc(Loc, Result, *IdentTable);
90  // Ensure the location actually points to one of the builting integral type
91  // names we're interested in. Otherwise, we might be getting this match from
92  // implicit code (e.g. an implicit assignment operator of a class containing
93  // an array of non-POD types).
94  if (!Tok.isOneOf(tok::kw_short, tok::kw_long, tok::kw_unsigned,
95  tok::kw_signed))
96  return;
97 
98  bool IsSigned;
99  unsigned Width;
100  const TargetInfo &TargetInfo = Result.Context->getTargetInfo();
101 
102  // Look for uses of short, long, long long and their unsigned versions.
103  switch (BuiltinLoc.getTypePtr()->getKind()) {
104  case BuiltinType::Short:
105  Width = TargetInfo.getShortWidth();
106  IsSigned = true;
107  break;
108  case BuiltinType::Long:
109  Width = TargetInfo.getLongWidth();
110  IsSigned = true;
111  break;
112  case BuiltinType::LongLong:
113  Width = TargetInfo.getLongLongWidth();
114  IsSigned = true;
115  break;
116  case BuiltinType::UShort:
117  Width = TargetInfo.getShortWidth();
118  IsSigned = false;
119  break;
120  case BuiltinType::ULong:
121  Width = TargetInfo.getLongWidth();
122  IsSigned = false;
123  break;
124  case BuiltinType::ULongLong:
125  Width = TargetInfo.getLongLongWidth();
126  IsSigned = false;
127  break;
128  default:
129  return;
130  }
131 
132  // We allow "unsigned short port" as that's reasonably common and required by
133  // the sockets API.
134  const StringRef Port = "unsigned short port";
135  const char *Data = Result.SourceManager->getCharacterData(Loc);
136  if (!std::strncmp(Data, Port.data(), Port.size()) &&
137  !isIdentifierBody(Data[Port.size()]))
138  return;
139 
140  std::string Replacement =
141  ((IsSigned ? SignedTypePrefix : UnsignedTypePrefix) + Twine(Width) +
142  TypeSuffix)
143  .str();
144 
145  // We don't add a fix-it as changing the type can easily break code,
146  // e.g. when a function requires a 'long' argument on all platforms.
147  // QualTypes are printed with implicit quotes.
148  diag(Loc, "consider replacing %0 with '%1'") << BuiltinLoc.getType()
149  << Replacement;
150 }
151 
152 } // namespace runtime
153 } // namespace google
154 } // namespace tidy
155 } // namespace clang
SourceLocation Loc
&#39;#&#39; location in the include directive
Base class for all clang-tidy checks.
const LangOptions & getLangOpts() const
Returns the language options from the context.
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers 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.
static constexpr llvm::StringLiteral Name
std::map< std::string, std::string > OptionMap
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.