https://github.com/Nechda updated
https://github.com/llvm/llvm-project/pull/126897
>From 6b9b6e44b7b122721a4371dbe20618a90753f666 Mon Sep 17 00:00:00 2001
From: Dmitry Nechitaev <nech...@gmail.com>
Date: Mon, 17 Feb 2025 13:30:46 +0300
Subject: [PATCH] Add AllowFalseEvaluated to clang-tidy
noexcept-move-constructor check
---
.../performance/NoexceptFunctionBaseCheck.cpp | 2 +-
.../performance/NoexceptFunctionBaseCheck.h | 8 ++-
clang-tools-extra/docs/ReleaseNotes.rst | 6 ++
.../performance/noexcept-move-constructor.rst | 9 +++
...move-constructor-allow-false-evaluated.cpp | 63 +++++++++++++++++++
5 files changed, 86 insertions(+), 2 deletions(-)
create mode 100644
clang-tools-extra/test/clang-tidy/checkers/performance/noexcept-move-constructor-allow-false-evaluated.cpp
diff --git
a/clang-tools-extra/clang-tidy/performance/NoexceptFunctionBaseCheck.cpp
b/clang-tools-extra/clang-tidy/performance/NoexceptFunctionBaseCheck.cpp
index 911cd1b533367..8371b6aafd8ba 100644
--- a/clang-tools-extra/clang-tidy/performance/NoexceptFunctionBaseCheck.cpp
+++ b/clang-tools-extra/clang-tidy/performance/NoexceptFunctionBaseCheck.cpp
@@ -30,7 +30,7 @@ void NoexceptFunctionBaseCheck::check(const
MatchFinder::MatchResult &Result) {
const Expr *NoexceptExpr = ProtoType->getNoexceptExpr();
if (NoexceptExpr) {
NoexceptExpr = NoexceptExpr->IgnoreImplicit();
- if (!isa<CXXBoolLiteralExpr>(NoexceptExpr))
+ if (!isa<CXXBoolLiteralExpr>(NoexceptExpr) && !AllowFalseEvaluated)
reportNoexceptEvaluatedToFalse(FuncDecl, NoexceptExpr);
return;
}
diff --git
a/clang-tools-extra/clang-tidy/performance/NoexceptFunctionBaseCheck.h
b/clang-tools-extra/clang-tidy/performance/NoexceptFunctionBaseCheck.h
index 4775219d7e439..cd1da1fbeca55 100644
--- a/clang-tools-extra/clang-tidy/performance/NoexceptFunctionBaseCheck.h
+++ b/clang-tools-extra/clang-tidy/performance/NoexceptFunctionBaseCheck.h
@@ -22,7 +22,8 @@ namespace clang::tidy::performance {
class NoexceptFunctionBaseCheck : public ClangTidyCheck {
public:
NoexceptFunctionBaseCheck(StringRef Name, ClangTidyContext *Context)
- : ClangTidyCheck(Name, Context) {}
+ : ClangTidyCheck(Name, Context)
+ , AllowFalseEvaluated(Options.getLocalOrGlobal("AllowFalseEvaluated",
false)) {}
bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
return LangOpts.CPlusPlus11 && LangOpts.CXXExceptions;
@@ -33,6 +34,10 @@ class NoexceptFunctionBaseCheck : public ClangTidyCheck {
return TK_IgnoreUnlessSpelledInSource;
}
+ void storeOptions(ClangTidyOptions::OptionMap &Opts) override {
+ Options.store(Opts, "AllowFalseEvaluated", AllowFalseEvaluated);
+ }
+
protected:
virtual DiagnosticBuilder
reportMissingNoexcept(const FunctionDecl *FuncDecl) = 0;
@@ -42,6 +47,7 @@ class NoexceptFunctionBaseCheck : public ClangTidyCheck {
static constexpr StringRef BindFuncDeclName = "FuncDecl";
private:
+ bool AllowFalseEvaluated;
utils::ExceptionSpecAnalyzer SpecAnalyzer;
};
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst
b/clang-tools-extra/docs/ReleaseNotes.rst
index 6b8fe22242417..457b0dbeb2383 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -110,6 +110,12 @@ Changes in existing checks
<clang-tidy/checks/misc/redundant-expression>` check by providing additional
examples and fixing some macro related false positives.
+- Improved :doc:`performance-noexcept-move-constructor
+ <clang-tidy/checks/performance/noexcept-move-constructor>` check by adding
+ a new (off-by-default) option `AllowFalseEvaluated`, which allows marking
+ move constructors with ``noexcept(expr)`` even if ``expr``
+ evaluates to ``false``.
+
Removed checks
^^^^^^^^^^^^^^
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/performance/noexcept-move-constructor.rst
b/clang-tools-extra/docs/clang-tidy/checks/performance/noexcept-move-constructor.rst
index 05f1d85f1af5a..288343723b19a 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/performance/noexcept-move-constructor.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/performance/noexcept-move-constructor.rst
@@ -11,3 +11,12 @@ evaluates to ``false`` (but is not a ``false`` literal
itself).
Move constructors of all the types used with STL containers, for example,
need to be declared ``noexcept``. Otherwise STL will choose copy constructors
instead. The same is valid for move assignment operations.
+
+Options
+-------
+
+.. option:: AllowFalseEvaluated
+
+ When `true`, the check will not generate any warning
+ if the ``expr`` in ``noexcept(expr)`` evaluates to ``false``.
+ Default is `false`.
diff --git
a/clang-tools-extra/test/clang-tidy/checkers/performance/noexcept-move-constructor-allow-false-evaluated.cpp
b/clang-tools-extra/test/clang-tidy/checkers/performance/noexcept-move-constructor-allow-false-evaluated.cpp
new file mode 100644
index 0000000000000..3552eaa7c50ea
--- /dev/null
+++
b/clang-tools-extra/test/clang-tidy/checkers/performance/noexcept-move-constructor-allow-false-evaluated.cpp
@@ -0,0 +1,63 @@
+// RUN: %check_clang_tidy %s performance-noexcept-move-constructor %t -- --
-fexceptions
+
+// RUN: %check_clang_tidy -check-suffix=CONFIG %s
performance-noexcept-move-constructor,performance-noexcept-destructor %t -- \
+// RUN: -config="{CheckOptions:
{performance-noexcept-move-constructor.AllowFalseEvaluated: true}}" \
+// RUN: -- -fexceptions
+
+namespace std
+{
+ template <typename T>
+ struct is_nothrow_move_constructible
+ {
+ static constexpr bool value = __is_nothrow_constructible(T,
__add_rvalue_reference(T));
+ };
+} // namespace std
+
+struct ThrowOnAnything {
+ ThrowOnAnything() noexcept(false);
+ ThrowOnAnything(ThrowOnAnything&&) noexcept(false);
+ // CHECK-MESSAGES-NOT: :[[@LINE-1]]:3: warning: move constructors should be
marked noexcept
+ // CHECK-MESSAGES-CONFIG-NOT: :[[@LINE-2]]:3: warning: move constructors
should be marked noexcept
+ ThrowOnAnything& operator=(ThrowOnAnything &&) noexcept(false);
+ ~ThrowOnAnything() noexcept(false);
+};
+
+struct C_1 {
+ static constexpr bool kFalse = false;
+ C_1(C_1&&) noexcept(kFalse) = default;
+ // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: noexcept specifier on the
move constructor evaluates to 'false' [performance-noexcept-move-constructor]
+ // CHECK-MESSAGES-CONFIG-NOT: :[[@LINE-2]]:25: warning: noexcept specifier
on the move constructor evaluates to 'false'
[performance-noexcept-move-constructor]
+
+ C_1 &operator=(C_1 &&) noexcept(kFalse);
+ // CHECK-MESSAGES: :[[@LINE-1]]:37: warning: noexcept specifier on the
move assignment operator evaluates to 'false'
[performance-noexcept-move-constructor]
+ // CHECK-MESSAGES-CONFIG-NOT: :[[@LINE-2]]:37: warning: noexcept specifier
on the move assignment operator evaluates to 'false'
[performance-noexcept-move-constructor]
+};
+
+struct C_2 {
+ static constexpr bool kEval =
std::is_nothrow_move_constructible<ThrowOnAnything>::value;
+ static_assert(!kEval); // kEval == false;
+
+ C_2(C_2&&) noexcept(kEval) = default;
+ // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: noexcept specifier on the
move constructor evaluates to 'false' [performance-noexcept-move-constructor]
+ // CHECK-MESSAGES-CONFIG-NOT: :[[@LINE-2]]:25: warning: noexcept specifier
on the move constructor evaluates to 'false'
[performance-noexcept-move-constructor]
+
+ C_2 &operator=(C_2 &&) noexcept(kEval);
+ // CHECK-MESSAGES: :[[@LINE-1]]:37: warning: noexcept specifier on the
move assignment operator evaluates to 'false'
[performance-noexcept-move-constructor]
+ // CHECK-MESSAGES-CONFIG-NOT: :[[@LINE-2]]:37: warning: noexcept specifier
on the move assignment operator evaluates to 'false'
[performance-noexcept-move-constructor]
+
+ ThrowOnAnything field;
+};
+
+struct C_3 {
+ static constexpr bool kEval =
std::is_nothrow_move_constructible<ThrowOnAnything>::value;
+ static_assert(!kEval); // kEval == false;
+
+ C_3(C_3&&) noexcept(kEval) = default;
+ // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: noexcept specifier on the
move constructor evaluates to 'false' [performance-noexcept-move-constructor]
+ // CHECK-MESSAGES-CONFIG-NOT: :[[@LINE-2]]:25: warning: noexcept specifier
on the move constructor evaluates to 'false'
[performance-noexcept-move-constructor]
+
+ ~C_3() noexcept(kEval) = default;
+ // CHECK-MESSAGES-CONFIG: :[[@LINE-1]]:21: warning: noexcept specifier on
the destructor evaluates to 'false'
+
+ ThrowOnAnything field;
+};
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
