clang-tools 10.0.0

ConvertMemberFunctionsToStatic.cpp
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1 //===--- ConvertMemberFunctionsToStatic.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 "ConvertMemberFunctionsToStatic.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/AST/DeclCXX.h"
13 #include "clang/AST/RecursiveASTVisitor.h"
14 #include "clang/ASTMatchers/ASTMatchFinder.h"
15 #include "clang/Basic/SourceLocation.h"
16
17 using namespace clang::ast_matchers;
18
19 namespace clang {
20 namespace tidy {
21 namespace readability {
22
23 AST_MATCHER(CXXMethodDecl, isStatic) { return Node.isStatic(); }
24
25 AST_MATCHER(CXXMethodDecl, hasTrivialBody) { return Node.hasTrivialBody(); }
26
27 AST_MATCHER(CXXMethodDecl, isOverloadedOperator) {
28 return Node.isOverloadedOperator();
29 }
30
31 AST_MATCHER(CXXRecordDecl, hasAnyDependentBases) {
32 return Node.hasAnyDependentBases();
33 }
34
35 AST_MATCHER(CXXMethodDecl, isTemplate) {
36 return Node.getTemplatedKind() != FunctionDecl::TK_NonTemplate;
37 }
38
39 AST_MATCHER(CXXMethodDecl, isDependentContext) {
40 return Node.isDependentContext();
41 }
42
43 AST_MATCHER(CXXMethodDecl, isInsideMacroDefinition) {
44 const ASTContext &Ctxt = Finder->getASTContext();
45 return clang::Lexer::makeFileCharRange(
46 clang::CharSourceRange::getCharRange(
47 Node.getTypeSourceInfo()->getTypeLoc().getSourceRange()),
48 Ctxt.getSourceManager(), Ctxt.getLangOpts())
49 .isInvalid();
50 }
51
52 AST_MATCHER_P(CXXMethodDecl, hasCanonicalDecl,
53 ast_matchers::internal::Matcher<CXXMethodDecl>, InnerMatcher) {
54 return InnerMatcher.matches(*Node.getCanonicalDecl(), Finder, Builder);
55 }
56
57 AST_MATCHER(CXXMethodDecl, usesThis) {
58 class FindUsageOfThis : public RecursiveASTVisitor<FindUsageOfThis> {
59 public:
60 bool Used = false;
61
62 bool VisitCXXThisExpr(const CXXThisExpr *E) {
63 Used = true;
64 return false; // Stop traversal.
65 }
66 } UsageOfThis;
67
68 // TraverseStmt does not modify its argument.
69 UsageOfThis.TraverseStmt(const_cast<Stmt *>(Node.getBody()));
70
71 return UsageOfThis.Used;
72 }
73
74 void ConvertMemberFunctionsToStatic::registerMatchers(MatchFinder *Finder) {
75 Finder->addMatcher(
76 cxxMethodDecl(
77 isDefinition(), isUserProvided(),
78 unless(anyOf(
79 isExpansionInSystemHeader(), isVirtual(), isStatic(),
80 hasTrivialBody(), isOverloadedOperator(), cxxConstructorDecl(),
81 cxxDestructorDecl(), cxxConversionDecl(), isTemplate(),
82 isDependentContext(),
83 ofClass(anyOf(
84 isLambda(),
85 hasAnyDependentBases()) // Method might become virtual
86 // depending on template base class.
87 ),
88 isInsideMacroDefinition(),
89 hasCanonicalDecl(isInsideMacroDefinition()), usesThis())))
90 .bind("x"),
91 this);
92 }
93
94 /// Obtain the original source code text from a SourceRange.
95 static StringRef getStringFromRange(SourceManager &SourceMgr,
96 const LangOptions &LangOpts,
97 SourceRange Range) {
98 if (SourceMgr.getFileID(Range.getBegin()) !=
99 SourceMgr.getFileID(Range.getEnd()))
100 return {};
101
102 return Lexer::getSourceText(CharSourceRange(Range, true), SourceMgr,
103 LangOpts);
104 }
105
106 static SourceRange getLocationOfConst(const TypeSourceInfo *TSI,
107 SourceManager &SourceMgr,
108 const LangOptions &LangOpts) {
109 assert(TSI);
110 const auto FTL = TSI->getTypeLoc().IgnoreParens().getAs<FunctionTypeLoc>();
111 assert(FTL);
112
113 SourceRange Range{FTL.getRParenLoc().getLocWithOffset(1),
114 FTL.getLocalRangeEnd()};
115 // Inside Range, there might be other keywords and trailing return types.
116 // Find the exact position of "const".
117 StringRef Text = getStringFromRange(SourceMgr, LangOpts, Range);
118 size_t Offset = Text.find("const");
119 if (Offset == StringRef::npos)
120 return {};
121
122 SourceLocation Start = Range.getBegin().getLocWithOffset(Offset);
123 return {Start, Start.getLocWithOffset(strlen("const") - 1)};
124 }
125
126 void ConvertMemberFunctionsToStatic::check(
127 const MatchFinder::MatchResult &Result) {
128 const auto *Definition = Result.Nodes.getNodeAs<CXXMethodDecl>("x");
129
130 // TODO: For out-of-line declarations, don't modify the source if the header
131 // is excluded by the -header-filter option.
132 DiagnosticBuilder Diag =
133 diag(Definition->getLocation(), "method %0 can be made static")
134 << Definition;
135
136 // TODO: Would need to remove those in a fix-it.
137 if (Definition->getMethodQualifiers().hasVolatile() ||
138 Definition->getMethodQualifiers().hasRestrict() ||
139 Definition->getRefQualifier() != RQ_None)
140 return;
141
142 const CXXMethodDecl *Declaration = Definition->getCanonicalDecl();
143
144 if (Definition->isConst()) {
145 // Make sure that we either remove 'const' on both declaration and
146 // definition or emit no fix-it at all.
147 SourceRange DefConst = getLocationOfConst(Definition->getTypeSourceInfo(),
148 *Result.SourceManager,
149 Result.Context->getLangOpts());
150
151 if (DefConst.isInvalid())
152 return;
153
154 if (Declaration != Definition) {
155 SourceRange DeclConst = getLocationOfConst(
156 Declaration->getTypeSourceInfo(), *Result.SourceManager,
157 Result.Context->getLangOpts());
158
159 if (DeclConst.isInvalid())
160 return;
161 Diag << FixItHint::CreateRemoval(DeclConst);
162 }
163
164 // Remove existing 'const' from both declaration and definition.
165 Diag << FixItHint::CreateRemoval(DefConst);
166 }
167 Diag << FixItHint::CreateInsertion(Declaration->getBeginLoc(), "static ");
168 }
169
170 } // namespace readability
171 } // namespace tidy
172 } // namespace clang
clang::ast_matchers
Definition: AbseilMatcher.h:14
Text
std::string Text
Definition: HTMLGenerator.cpp:80
clang::tidy::readability::getStringFromRange
static StringRef getStringFromRange(SourceManager &SourceMgr, const LangOptions &LangOpts, SourceRange Range)
Obtain the original source code text from a SourceRange.
Definition: ConvertMemberFunctionsToStatic.cpp:95
clang::tidy::readability::getLocationOfConst
static SourceRange getLocationOfConst(const TypeSourceInfo *TSI, SourceManager &SourceMgr, const LangOptions &LangOpts)
Definition: ConvertMemberFunctionsToStatic.cpp:106
clang::ast_matchers::AST_MATCHER
AST_MATCHER(Expr, isMacroID)
Definition: PreferIsaOrDynCastInConditionalsCheck.cpp:18
Builder
CodeCompletionBuilder Builder
Definition: CodeCompletionStringsTests.cpp:35
Offset
size_t Offset
Definition: CodeComplete.cpp:1022
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
Range
CharSourceRange Range
SourceRange for the file name.
Definition: IncludeOrderCheck.cpp:38
E
const Expr * E
Definition: AvoidBindCheck.cpp:82
ConvertMemberFunctionsToStatic.h
clang::tidy::readability::AST_MATCHER_P
AST_MATCHER_P(CXXMethodDecl, hasCanonicalDecl, ast_matchers::internal::Matcher< CXXMethodDecl >, InnerMatcher)
Definition: ConvertMemberFunctionsToStatic.cpp:52
clang::tidy::readability::FindUsageOfThis
Definition: MakeMemberFunctionConstCheck.cpp:52