1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
//===--- UnnecessaryCopyInitialization.h - clang-tidy------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PERFORMANCE_UNNECESSARY_COPY_INITIALIZATION_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PERFORMANCE_UNNECESSARY_COPY_INITIALIZATION_H
#include "../ClangTidyCheck.h"
#include "clang/AST/Decl.h"
namespace clang::tidy::performance {
// The check detects local variable declarations that are copy initialized with
// the const reference of a function call or the const reference of a method
// call whose object is guaranteed to outlive the variable's scope and suggests
// to use a const reference.
//
// The check currently only understands a subset of variables that are
// guaranteed to outlive the const reference returned, namely: const variables,
// const references, and const pointers to const.
class UnnecessaryCopyInitialization : public ClangTidyCheck {
public:
UnnecessaryCopyInitialization(StringRef Name, ClangTidyContext *Context);
bool isLanguageVersionSupported(const LangOptions &LangOpts) const override{
return LangOpts.CPlusPlus;
}
void registerMatchers(ast_matchers::MatchFinder *Finder) override;
void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
protected:
// A helper to manipulate the state common to
// `CopyFromMethodReturn` and `CopyFromLocalVar`.
struct CheckContext {
const VarDecl &Var;
const Stmt &BlockStmt;
const DeclStmt &VarDeclStmt;
clang::ASTContext &ASTCtx;
const bool IssueFix;
const bool IsVarUnused;
const bool IsVarOnlyUsedAsConst;
};
// Create diagnostics. These are virtual so that derived classes can change
// behaviour.
virtual void diagnoseCopyFromMethodReturn(const CheckContext &Ctx);
virtual void diagnoseCopyFromLocalVar(const CheckContext &Ctx,
const VarDecl &OldVar);
private:
void handleCopyFromMethodReturn(const CheckContext &Ctx,
const VarDecl *ObjectArg);
void handleCopyFromLocalVar(const CheckContext &Ctx, const VarDecl &OldVar);
void maybeIssueFixes(const CheckContext &Ctx, DiagnosticBuilder &Diagnostic);
const std::vector<StringRef> AllowedTypes;
const std::vector<StringRef> ExcludedContainerTypes;
};
} // namespace clang::tidy::performance
#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_PERFORMANCE_UNNECESSARY_COPY_INITIALIZATION_H
|
