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/TargetInfo.h"
16 
17 namespace clang {
18 namespace tidy {
19 namespace google {
20 namespace runtime {
21 
22 using namespace ast_matchers;
23 
24 IntegerTypesCheck::IntegerTypesCheck(StringRef Name, ClangTidyContext *Context)
25     : ClangTidyCheck(Name, Context),
26       UnsignedTypePrefix(Options.get("UnsignedTypePrefix", "uint")),
27       SignedTypePrefix(Options.get("SignedTypePrefix", "int")),
28       TypeSuffix(Options.get("TypeSuffix", "")) {}
29 
30 void IntegerTypesCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
31   Options.store(Opts, "UnsignedTypePrefix", UnsignedTypePrefix);
32   Options.store(Opts, "SignedTypePrefix", SignedTypePrefix);
33   Options.store(Opts, "TypeSuffix", TypeSuffix);
34 }
35 
36 void IntegerTypesCheck::registerMatchers(MatchFinder *Finder) {
37   // Find all TypeLocs. The relevant Style Guide rule only applies to C++.
38   if (getLangOpts().CPlusPlus)
39     Finder->addMatcher(typeLoc(loc(isInteger())).bind("tl"), this);
40 }
41 
42 void IntegerTypesCheck::check(const MatchFinder::MatchResult &Result) {
43   auto TL = *Result.Nodes.getNodeAs<TypeLoc>("tl");
44   SourceLocation Loc = TL.getLocStart();
45 
46   if (Loc.isInvalid() || Loc.isMacroID())
47     return;
48 
49   // Look through qualification.
50   if (auto QualLoc = TL.getAs<QualifiedTypeLoc>())
51     TL = QualLoc.getUnqualifiedLoc();
52 
53   auto BuiltinLoc = TL.getAs<BuiltinTypeLoc>();
54   if (!BuiltinLoc)
55     return;
56 
57   bool IsSigned;
58   unsigned Width;
59   const TargetInfo &TargetInfo = Result.Context->getTargetInfo();
60 
61   // Look for uses of short, long, long long and their unsigned versions.
62   switch (BuiltinLoc.getTypePtr()->getKind()) {
63   case BuiltinType::Short:
64     Width = TargetInfo.getShortWidth();
65     IsSigned = true;
66     break;
67   case BuiltinType::Long:
68     Width = TargetInfo.getLongWidth();
69     IsSigned = true;
70     break;
71   case BuiltinType::LongLong:
72     Width = TargetInfo.getLongLongWidth();
73     IsSigned = true;
74     break;
75   case BuiltinType::UShort:
76     Width = TargetInfo.getShortWidth();
77     IsSigned = false;
78     break;
79   case BuiltinType::ULong:
80     Width = TargetInfo.getLongWidth();
81     IsSigned = false;
82     break;
83   case BuiltinType::ULongLong:
84     Width = TargetInfo.getLongLongWidth();
85     IsSigned = false;
86     break;
87   default:
88     return;
89   }
90 
91   // We allow "unsigned short port" as that's reasonably common and required by
92   // the sockets API.
93   const StringRef Port = "unsigned short port";
94   const char *Data = Result.SourceManager->getCharacterData(Loc);
95   if (!std::strncmp(Data, Port.data(), Port.size()) &&
96       !isIdentifierBody(Data[Port.size()]))
97     return;
98 
99   std::string Replacement =
100       ((IsSigned ? SignedTypePrefix : UnsignedTypePrefix) + Twine(Width) +
101        TypeSuffix)
102           .str();
103 
104   // We don't add a fix-it as changing the type can easily break code,
105   // e.g. when a function requires a 'long' argument on all platforms.
106   // QualTypes are printed with implicit quotes.
107   diag(Loc, "consider replacing %0 with '%1'") << BuiltinLoc.getType()
108                                                << Replacement;
109 }
110 
111 } // namespace runtime
112 } // namespace google
113 } // namespace tidy
114 } // namespace clang
115