1 //===--- MacroUsageCheck.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 "MacroUsageCheck.h"
10 #include "clang/Frontend/CompilerInstance.h"
11 #include "clang/Lex/PPCallbacks.h"
12 #include "clang/Lex/Preprocessor.h"
13 #include "llvm/ADT/STLExtras.h"
14 #include "llvm/Support/Regex.h"
15 #include <algorithm>
16 #include <cctype>
17 #include <functional>
18
19 namespace clang {
20 namespace tidy {
21 namespace cppcoreguidelines {
22
isCapsOnly(StringRef Name)23 static bool isCapsOnly(StringRef Name) {
24 return llvm::all_of(Name, [](const char C) {
25 return std::isupper(C) || std::isdigit(C) || C == '_';
26 });
27 }
28
29 namespace {
30
31 class MacroUsageCallbacks : public PPCallbacks {
32 public:
MacroUsageCallbacks(MacroUsageCheck * Check,const SourceManager & SM,StringRef RegExpStr,bool CapsOnly,bool IgnoreCommandLine)33 MacroUsageCallbacks(MacroUsageCheck *Check, const SourceManager &SM,
34 StringRef RegExpStr, bool CapsOnly,
35 bool IgnoreCommandLine)
36 : Check(Check), SM(SM), RegExp(RegExpStr), CheckCapsOnly(CapsOnly),
37 IgnoreCommandLineMacros(IgnoreCommandLine) {}
MacroDefined(const Token & MacroNameTok,const MacroDirective * MD)38 void MacroDefined(const Token &MacroNameTok,
39 const MacroDirective *MD) override {
40 if (SM.isWrittenInBuiltinFile(MD->getLocation()) ||
41 MD->getMacroInfo()->isUsedForHeaderGuard() ||
42 MD->getMacroInfo()->getNumTokens() == 0)
43 return;
44
45 if (IgnoreCommandLineMacros &&
46 SM.isWrittenInCommandLineFile(MD->getLocation()))
47 return;
48
49 StringRef MacroName = MacroNameTok.getIdentifierInfo()->getName();
50 if (MacroName == "__GCC_HAVE_DWARF2_CFI_ASM")
51 return;
52 if (!CheckCapsOnly && !RegExp.match(MacroName))
53 Check->warnMacro(MD, MacroName);
54
55 if (CheckCapsOnly && !isCapsOnly(MacroName))
56 Check->warnNaming(MD, MacroName);
57 }
58
59 private:
60 MacroUsageCheck *Check;
61 const SourceManager &SM;
62 const llvm::Regex RegExp;
63 bool CheckCapsOnly;
64 bool IgnoreCommandLineMacros;
65 };
66 } // namespace
67
storeOptions(ClangTidyOptions::OptionMap & Opts)68 void MacroUsageCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
69 Options.store(Opts, "AllowedRegexp", AllowedRegexp);
70 Options.store(Opts, "CheckCapsOnly", CheckCapsOnly);
71 Options.store(Opts, "IgnoreCommandLineMacros", IgnoreCommandLineMacros);
72 }
73
registerPPCallbacks(const SourceManager & SM,Preprocessor * PP,Preprocessor * ModuleExpanderPP)74 void MacroUsageCheck::registerPPCallbacks(const SourceManager &SM,
75 Preprocessor *PP,
76 Preprocessor *ModuleExpanderPP) {
77 PP->addPPCallbacks(std::make_unique<MacroUsageCallbacks>(
78 this, SM, AllowedRegexp, CheckCapsOnly, IgnoreCommandLineMacros));
79 }
80
warnMacro(const MacroDirective * MD,StringRef MacroName)81 void MacroUsageCheck::warnMacro(const MacroDirective *MD, StringRef MacroName) {
82 const MacroInfo *Info = MD->getMacroInfo();
83 StringRef Message;
84
85 if (llvm::all_of(Info->tokens(), std::mem_fn(&Token::isLiteral)))
86 Message = "macro '%0' used to declare a constant; consider using a "
87 "'constexpr' constant";
88 // A variadic macro is function-like at the same time. Therefore variadic
89 // macros are checked first and will be excluded for the function-like
90 // diagnostic.
91 else if (Info->isVariadic())
92 Message = "variadic macro '%0' used; consider using a 'constexpr' "
93 "variadic template function";
94 else if (Info->isFunctionLike())
95 Message = "function-like macro '%0' used; consider a 'constexpr' template "
96 "function";
97
98 if (!Message.empty())
99 diag(MD->getLocation(), Message) << MacroName;
100 }
101
warnNaming(const MacroDirective * MD,StringRef MacroName)102 void MacroUsageCheck::warnNaming(const MacroDirective *MD,
103 StringRef MacroName) {
104 diag(MD->getLocation(), "macro definition does not define the macro name "
105 "'%0' using all uppercase characters")
106 << MacroName;
107 }
108
109 } // namespace cppcoreguidelines
110 } // namespace tidy
111 } // namespace clang
112