1 //===--- LambdaFunctionNameCheck.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 "LambdaFunctionNameCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/AST/DeclCXX.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/ASTMatchers/ASTMatchers.h"
14 #include "clang/Frontend/CompilerInstance.h"
15 #include "clang/Lex/MacroInfo.h"
16 #include "clang/Lex/Preprocessor.h"
17
18 using namespace clang::ast_matchers;
19
20 namespace clang::tidy::bugprone {
21
22 namespace {
23
24 static constexpr bool DefaultIgnoreMacros = false;
25
26 // Keep track of macro expansions that contain both __FILE__ and __LINE__. If
27 // such a macro also uses __func__ or __FUNCTION__, we don't want to issue a
28 // warning because __FILE__ and __LINE__ may be useful even if __func__ or
29 // __FUNCTION__ is not, especially if the macro could be used in the context of
30 // either a function body or a lambda body.
31 class MacroExpansionsWithFileAndLine : public PPCallbacks {
32 public:
MacroExpansionsWithFileAndLine(LambdaFunctionNameCheck::SourceRangeSet * SME)33 explicit MacroExpansionsWithFileAndLine(
34 LambdaFunctionNameCheck::SourceRangeSet *SME)
35 : SuppressMacroExpansions(SME) {}
36
MacroExpands(const Token & MacroNameTok,const MacroDefinition & MD,SourceRange Range,const MacroArgs * Args)37 void MacroExpands(const Token &MacroNameTok,
38 const MacroDefinition &MD, SourceRange Range,
39 const MacroArgs *Args) override {
40 bool HasFile = false;
41 bool HasLine = false;
42 for (const auto& T : MD.getMacroInfo()->tokens()) {
43 if (T.is(tok::identifier)) {
44 StringRef IdentName = T.getIdentifierInfo()->getName();
45 if (IdentName == "__FILE__") {
46 HasFile = true;
47 } else if (IdentName == "__LINE__") {
48 HasLine = true;
49 }
50 }
51 }
52 if (HasFile && HasLine) {
53 SuppressMacroExpansions->insert(Range);
54 }
55 }
56
57 private:
58 LambdaFunctionNameCheck::SourceRangeSet* SuppressMacroExpansions;
59 };
60
AST_MATCHER(CXXMethodDecl,isInLambda)61 AST_MATCHER(CXXMethodDecl, isInLambda) { return Node.getParent()->isLambda(); }
62
63 } // namespace
64
LambdaFunctionNameCheck(StringRef Name,ClangTidyContext * Context)65 LambdaFunctionNameCheck::LambdaFunctionNameCheck(StringRef Name,
66 ClangTidyContext *Context)
67 : ClangTidyCheck(Name, Context),
68 IgnoreMacros(
69 Options.getLocalOrGlobal("IgnoreMacros", DefaultIgnoreMacros)) {}
70
storeOptions(ClangTidyOptions::OptionMap & Opts)71 void LambdaFunctionNameCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
72 Options.store(Opts, "IgnoreMacros", IgnoreMacros);
73 }
74
registerMatchers(MatchFinder * Finder)75 void LambdaFunctionNameCheck::registerMatchers(MatchFinder *Finder) {
76 Finder->addMatcher(
77 cxxMethodDecl(isInLambda(),
78 hasBody(forEachDescendant(
79 predefinedExpr(hasAncestor(cxxMethodDecl().bind("fn")))
80 .bind("E"))),
81 equalsBoundNode("fn")),
82 this);
83 }
84
registerPPCallbacks(const SourceManager & SM,Preprocessor * PP,Preprocessor * ModuleExpanderPP)85 void LambdaFunctionNameCheck::registerPPCallbacks(
86 const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
87 PP->addPPCallbacks(std::make_unique<MacroExpansionsWithFileAndLine>(
88 &SuppressMacroExpansions));
89 }
90
check(const MatchFinder::MatchResult & Result)91 void LambdaFunctionNameCheck::check(const MatchFinder::MatchResult &Result) {
92 const auto *E = Result.Nodes.getNodeAs<PredefinedExpr>("E");
93 if (E->getIdentKind() != PredefinedIdentKind::Func &&
94 E->getIdentKind() != PredefinedIdentKind::Function) {
95 // We don't care about other PredefinedExprs.
96 return;
97 }
98 if (E->getLocation().isMacroID()) {
99 if (IgnoreMacros)
100 return;
101
102 auto ER =
103 Result.SourceManager->getImmediateExpansionRange(E->getLocation());
104 if (SuppressMacroExpansions.find(ER.getAsRange()) !=
105 SuppressMacroExpansions.end()) {
106 // This is a macro expansion for which we should not warn.
107 return;
108 }
109 }
110
111 diag(E->getLocation(),
112 "inside a lambda, '%0' expands to the name of the function call "
113 "operator; consider capturing the name of the enclosing function "
114 "explicitly")
115 << PredefinedExpr::getIdentKindName(E->getIdentKind());
116 }
117
118 } // namespace clang::tidy::bugprone
119