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
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
|
//===--- NoAutomaticMoveCheck.cpp - clang-tidy ----------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "NoAutomaticMoveCheck.h"
#include "../utils/Matchers.h"
#include "../utils/OptionsUtils.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
using namespace clang::ast_matchers;
namespace clang::tidy::performance {
namespace {
AST_MATCHER(VarDecl, isNRVOVariable) { return Node.isNRVOVariable(); }
} // namespace
NoAutomaticMoveCheck::NoAutomaticMoveCheck(StringRef Name,
ClangTidyContext *Context)
: ClangTidyCheck(Name, Context),
AllowedTypes(
utils::options::parseStringList(Options.get("AllowedTypes", ""))) {}
void NoAutomaticMoveCheck::registerMatchers(MatchFinder *Finder) {
const auto NonNrvoConstLocalVariable =
varDecl(hasLocalStorage(), unless(hasType(lValueReferenceType())),
unless(isNRVOVariable()),
hasType(qualType(
isConstQualified(),
hasCanonicalType(matchers::isExpensiveToCopy()),
unless(hasDeclaration(namedDecl(
matchers::matchesAnyListedName(AllowedTypes)))))))
.bind("vardecl");
// A matcher for a `DstT::DstT(const Src&)` where DstT also has a
// `DstT::DstT(Src&&)`.
const auto LValueRefCtor = cxxConstructorDecl(
hasParameter(0,
hasType(lValueReferenceType(pointee(type().bind("SrcT"))))),
ofClass(cxxRecordDecl(hasMethod(cxxConstructorDecl(
hasParameter(0, hasType(rValueReferenceType(
pointee(type(equalsBoundNode("SrcT")))))))))));
// A matcher for `DstT::DstT(const Src&&)`, which typically comes from an
// instantiation of `template <typename U> DstT::DstT(U&&)`.
const auto ConstRefRefCtor = cxxConstructorDecl(
parameterCountIs(1),
hasParameter(0,
hasType(rValueReferenceType(pointee(isConstQualified())))));
Finder->addMatcher(
traverse(
TK_AsIs,
returnStmt(hasReturnValue(
ignoringElidableConstructorCall(ignoringParenImpCasts(
cxxConstructExpr(
hasDeclaration(anyOf(LValueRefCtor, ConstRefRefCtor)),
hasArgument(0, ignoringParenImpCasts(declRefExpr(
to(NonNrvoConstLocalVariable)))))
.bind("ctor_call")))))),
this);
}
void NoAutomaticMoveCheck::check(const MatchFinder::MatchResult &Result) {
const auto *Var = Result.Nodes.getNodeAs<VarDecl>("vardecl");
const auto *CtorCall = Result.Nodes.getNodeAs<Expr>("ctor_call");
diag(CtorCall->getExprLoc(), "constness of '%0' prevents automatic move")
<< Var->getName();
}
void NoAutomaticMoveCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
Options.store(Opts, "AllowedTypes",
utils::options::serializeStringList(AllowedTypes));
}
} // namespace clang::tidy::performance
|
