[clang-tools-extra] 90d42b1 - [clang-tidy] Skip private default ctors in modernize-use-equals-default
Alexander Shaposhnikov via cfe-commits
cfe-commits at lists.llvm.org
Thu Oct 20 15:04:57 PDT 2022
Author: Alexander Shaposhnikov
Date: 2022-10-20T22:04:33Z
New Revision: 90d42b1cab04b76e9e934f1e5076f014d1195e72
URL: https://github.com/llvm/llvm-project/commit/90d42b1cab04b76e9e934f1e5076f014d1195e72
DIFF: https://github.com/llvm/llvm-project/commit/90d42b1cab04b76e9e934f1e5076f014d1195e72.diff
LOG: [clang-tidy] Skip private default ctors in modernize-use-equals-default
For c++17 (i.e. before c++20) making a private default ctor explicitly defaulted
might expose the previously intentionally disallowed initializations, e.g.
class Tag { Tag() {} friend class Widget; }; is not equivalent to
class Tag { Tag() = default; friend class Widget; };
since in the latter case Tag is treated as an aggregate despite having a declaration
of the default constructor. This diff makes modernize-use-equals-default skip
in-class empty nonpublic default ctors to avoid code breakages.
Test plan: ninja check-all
Differential revision: https://reviews.llvm.org/D136224
Added:
clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default-cxx17.cpp
clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default-cxx20.cpp
Modified:
clang-tools-extra/clang-tidy/modernize/UseEqualsDefaultCheck.cpp
clang-tools-extra/docs/ReleaseNotes.rst
clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default.cpp
Removed:
################################################################################
diff --git a/clang-tools-extra/clang-tidy/modernize/UseEqualsDefaultCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseEqualsDefaultCheck.cpp
index 165840b72e7aa..e72ea76114783 100644
--- a/clang-tools-extra/clang-tidy/modernize/UseEqualsDefaultCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseEqualsDefaultCheck.cpp
@@ -217,6 +217,10 @@ void UseEqualsDefaultCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
Options.store(Opts, "IgnoreMacros", IgnoreMacros);
}
+namespace {
+AST_MATCHER(CXXMethodDecl, isOutOfLine) { return Node.isOutOfLine(); }
+} // namespace
+
void UseEqualsDefaultCheck::registerMatchers(MatchFinder *Finder) {
// Skip unions/union-like classes since their constructors behave
diff erently
// when defaulted vs. empty.
@@ -224,6 +228,12 @@ void UseEqualsDefaultCheck::registerMatchers(MatchFinder *Finder) {
anyOf(isUnion(),
has(fieldDecl(isImplicit(), hasType(cxxRecordDecl(isUnion()))))));
+ const LangOptions &LangOpts = getLangOpts();
+ auto IsPublicOrOutOfLineUntilCPP20 =
+ LangOpts.CPlusPlus20
+ ? cxxConstructorDecl()
+ : cxxConstructorDecl(anyOf(isOutOfLine(), isPublic()));
+
// Destructor.
Finder->addMatcher(
cxxDestructorDecl(unless(hasParent(IsUnionLikeClass)), isDefinition())
@@ -235,7 +245,8 @@ void UseEqualsDefaultCheck::registerMatchers(MatchFinder *Finder) {
anyOf(
// Default constructor.
allOf(unless(hasAnyConstructorInitializer(isWritten())),
- unless(isVariadic()), parameterCountIs(0)),
+ unless(isVariadic()), parameterCountIs(0),
+ IsPublicOrOutOfLineUntilCPP20),
// Copy constructor.
allOf(isCopyConstructor(),
// Discard constructors that can be used as a copy
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 735fedbce5496..68995a9d3f190 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -158,7 +158,8 @@ Changes in existing checks
The check now skips unions/union-like classes since in this case a default constructor
with empty body is not equivalent to the explicitly defaulted one, variadic constructors
since they cannot be explicitly defaulted. The check also skips copy assignment operators
- with nonstandard return types. The check is restricted to c++11-or-later.
+ with nonstandard return types, private/protected default constructors for C++17 or earlier.
+ The check is restricted to C++11 or later.
- Change the default behavior of :doc:`readability-avoid-const-params-in-decls
<clang-tidy/checks/readability/avoid-const-params-in-decls>` to not
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default-cxx17.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default-cxx17.cpp
new file mode 100644
index 0000000000000..3bbc6296816b1
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default-cxx17.cpp
@@ -0,0 +1,17 @@
+// RUN: %check_clang_tidy -std=c++17 %s modernize-use-equals-default %t -- -- -fno-delayed-template-parsing -fexceptions
+
+// Private constructor/destructor.
+class Priv {
+ Priv() {}
+ ~Priv() {}
+ // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use '= default'
+ // CHECK-FIXES: ~Priv() = default;
+};
+
+class PrivOutOfLine {
+ PrivOutOfLine();
+};
+
+PrivOutOfLine::PrivOutOfLine() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: use '= default'
+// CHECK-FIXES: PrivOutOfLine::PrivOutOfLine() = default;
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default-cxx20.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default-cxx20.cpp
new file mode 100644
index 0000000000000..38dfa5ebaea7e
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default-cxx20.cpp
@@ -0,0 +1,19 @@
+// RUN: %check_clang_tidy -std=c++20 %s modernize-use-equals-default %t -- -- -fno-delayed-template-parsing -fexceptions
+
+// Private constructor/destructor.
+class Priv {
+ Priv() {}
+ // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use '= default'
+ // CHECK-FIXES: Priv() = default;
+ ~Priv() {}
+ // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use '= default'
+ // CHECK-FIXES: ~Priv() = default;
+};
+
+class PrivOutOfLine {
+ PrivOutOfLine();
+};
+
+PrivOutOfLine::PrivOutOfLine() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: use '= default'
+// CHECK-FIXES: PrivOutOfLine::PrivOutOfLine() = default;
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default.cpp
index 493cfa21a8371..6482c3a82241e 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default.cpp
@@ -90,14 +90,16 @@ class CM {
// Private constructor/destructor.
class Priv {
- Priv() {}
- // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use '= default'
- // CHECK-FIXES: Priv() = default;
+ Priv();
~Priv() {};
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use '= default'
// CHECK-FIXES: ~Priv() = default;
};
+Priv::Priv() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: use '= default'
+// CHECK-FIXES: Priv::Priv() = default;
+
// struct.
struct ST {
ST() {}
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