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/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 
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 
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 
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   Finder->addMatcher(typeLoc(loc(isInteger())).bind("tl"), this);
61   IdentTable = llvm::make_unique<IdentifierTable>(getLangOpts());
62 }
63 
64 void IntegerTypesCheck::check(const MatchFinder::MatchResult &Result) {
65   auto TL = *Result.Nodes.getNodeAs<TypeLoc>("tl");
66   SourceLocation Loc = TL.getLocStart();
67 
68   if (Loc.isInvalid() || Loc.isMacroID())
69     return;
70 
71   // Look through qualification.
72   if (auto QualLoc = TL.getAs<QualifiedTypeLoc>())
73     TL = QualLoc.getUnqualifiedLoc();
74 
75   auto BuiltinLoc = TL.getAs<BuiltinTypeLoc>();
76   if (!BuiltinLoc)
77     return;
78 
79   Token Tok = getTokenAtLoc(Loc, Result, *IdentTable);
80   // Ensure the location actually points to one of the builting integral type
81   // names we're interested in. Otherwise, we might be getting this match from
82   // implicit code (e.g. an implicit assignment operator of a class containing
83   // an array of non-POD types).
84   if (!Tok.isOneOf(tok::kw_short, tok::kw_long, tok::kw_unsigned,
85                    tok::kw_signed))
86     return;
87 
88   bool IsSigned;
89   unsigned Width;
90   const TargetInfo &TargetInfo = Result.Context->getTargetInfo();
91 
92   // Look for uses of short, long, long long and their unsigned versions.
93   switch (BuiltinLoc.getTypePtr()->getKind()) {
94   case BuiltinType::Short:
95     Width = TargetInfo.getShortWidth();
96     IsSigned = true;
97     break;
98   case BuiltinType::Long:
99     Width = TargetInfo.getLongWidth();
100     IsSigned = true;
101     break;
102   case BuiltinType::LongLong:
103     Width = TargetInfo.getLongLongWidth();
104     IsSigned = true;
105     break;
106   case BuiltinType::UShort:
107     Width = TargetInfo.getShortWidth();
108     IsSigned = false;
109     break;
110   case BuiltinType::ULong:
111     Width = TargetInfo.getLongWidth();
112     IsSigned = false;
113     break;
114   case BuiltinType::ULongLong:
115     Width = TargetInfo.getLongLongWidth();
116     IsSigned = false;
117     break;
118   default:
119     return;
120   }
121 
122   // We allow "unsigned short port" as that's reasonably common and required by
123   // the sockets API.
124   const StringRef Port = "unsigned short port";
125   const char *Data = Result.SourceManager->getCharacterData(Loc);
126   if (!std::strncmp(Data, Port.data(), Port.size()) &&
127       !isIdentifierBody(Data[Port.size()]))
128     return;
129 
130   std::string Replacement =
131       ((IsSigned ? SignedTypePrefix : UnsignedTypePrefix) + Twine(Width) +
132        TypeSuffix)
133           .str();
134 
135   // We don't add a fix-it as changing the type can easily break code,
136   // e.g. when a function requires a 'long' argument on all platforms.
137   // QualTypes are printed with implicit quotes.
138   diag(Loc, "consider replacing %0 with '%1'") << BuiltinLoc.getType()
139                                                << Replacement;
140 }
141 
142 } // namespace runtime
143 } // namespace google
144 } // namespace tidy
145 } // namespace clang
146