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
getTokenAtLoc(SourceLocation Loc,const MatchFinder::MatchResult & MatchResult,IdentifierTable & IdentTable)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
IntegerTypesCheck(StringRef Name,ClangTidyContext * Context)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
storeOptions(ClangTidyOptions::OptionMap & Opts)50 void IntegerTypesCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
51 Options.store(Opts, "UnsignedTypePrefix", UnsignedTypePrefix);
52 Options.store(Opts, "SignedTypePrefix", SignedTypePrefix);
53 Options.store(Opts, "TypeSuffix", TypeSuffix);
54 }
55
registerMatchers(MatchFinder * Finder)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
check(const MatchFinder::MatchResult & Result)73 void IntegerTypesCheck::check(const MatchFinder::MatchResult &Result) {
74 auto TL = *Result.Nodes.getNodeAs<TypeLoc>("tl");
75 SourceLocation Loc = TL.getLocStart();
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
155