https://github.com/higher-performance updated
https://github.com/llvm/llvm-project/pull/114255
>From 2835f0eae90061d390d1b011b6a98bf43be1a0c6 Mon Sep 17 00:00:00 2001
From: higher-performance <higher.performance.git...@gmail.com>
Date: Wed, 30 Oct 2024 12:01:00 -0400
Subject: [PATCH] Extend bugprone-use-after-move check to handle
std::optional::reset() and std::any::reset() similarly to smart pointers
---
.../clang-tidy/bugprone/UseAfterMoveCheck.cpp | 9 +++--
clang-tools-extra/docs/ReleaseNotes.rst | 5 +++
.../checks/bugprone/use-after-move.rst | 15 +++++---
.../checkers/bugprone/use-after-move.cpp | 37 ++++++++++++++++++-
4 files changed, 54 insertions(+), 12 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/UseAfterMoveCheck.cpp
b/clang-tools-extra/clang-tidy/bugprone/UseAfterMoveCheck.cpp
index 8f4b5e8092ddaa..960133159dbbf5 100644
--- a/clang-tools-extra/clang-tidy/bugprone/UseAfterMoveCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/UseAfterMoveCheck.cpp
@@ -315,9 +315,10 @@ void UseAfterMoveFinder::getReinits(
"::std::unordered_map", "::std::unordered_multiset",
"::std::unordered_multimap"))))));
- auto StandardSmartPointerTypeMatcher = hasType(hasUnqualifiedDesugaredType(
- recordType(hasDeclaration(cxxRecordDecl(hasAnyName(
- "::std::unique_ptr", "::std::shared_ptr", "::std::weak_ptr"))))));
+ auto StandardResettableOwnerTypeMatcher = hasType(
+ hasUnqualifiedDesugaredType(recordType(hasDeclaration(cxxRecordDecl(
+ hasAnyName("::std::unique_ptr", "::std::shared_ptr",
+ "::std::weak_ptr", "::std::optional", "::std::any"))))));
// Matches different types of reinitialization.
auto ReinitMatcher =
@@ -340,7 +341,7 @@ void UseAfterMoveFinder::getReinits(
callee(cxxMethodDecl(hasAnyName("clear", "assign")))),
// reset() on standard smart pointers.
cxxMemberCallExpr(
- on(expr(DeclRefMatcher, StandardSmartPointerTypeMatcher)),
+ on(expr(DeclRefMatcher,
StandardResettableOwnerTypeMatcher)),
callee(cxxMethodDecl(hasName("reset")))),
// Methods that have the [[clang::reinitializes]] attribute.
cxxMemberCallExpr(
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst
b/clang-tools-extra/docs/ReleaseNotes.rst
index 442fb7180555ea..ace1c037aba0c4 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -190,6 +190,11 @@ Changes in existing checks
<clang-tidy/checks/bugprone/unsafe-functions>` check to allow specifying
additional functions to match.
+- Improved :doc:`bugprone-use-after-move
+ <clang-tidy/checks/bugprone/use-after-move>` to avoid triggering on
+ ``reset()`` calls on moved-from ``std::optional`` and ``std::any`` objects,
+ similarly to smart pointers.
+
- Improved :doc:`cert-flp30-c <clang-tidy/checks/cert/flp30-c>` check to
fix false positive that floating point variable is only used in increment
expression.
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/use-after-move.rst
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/use-after-move.rst
index 08bb5374bab1f4..965fc2d3c29e24 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/bugprone/use-after-move.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/bugprone/use-after-move.rst
@@ -196,11 +196,13 @@ Any occurrence of the moved variable that is not a
reinitialization (see below)
is considered to be a use.
An exception to this are objects of type ``std::unique_ptr``,
-``std::shared_ptr`` and ``std::weak_ptr``, which have defined move behavior
-(objects of these classes are guaranteed to be empty after they have been moved
-from). Therefore, an object of these classes will only be considered to be used
-if it is dereferenced, i.e. if ``operator*``, ``operator->`` or ``operator[]``
-(in the case of ``std::unique_ptr<T []>``) is called on it.
+``std::shared_ptr``, ``std::weak_ptr``, ``std::optional``, and ``std::any``.
+An exception to this are objects of type ``std::unique_ptr``,
+``std::shared_ptr``, ``std::weak_ptr``, ``std::optional``, and ``std::any``,
which
+can be reinitialized via ``reset``. For smart pointers specifically, the
+moved-from objects have a well-defined state of being ``nullptr``s, and only
+``operator*``, ``operator->`` and ``operator[]`` are considered bad accesses as
+they would be dereferencing a ``nullptr``.
If multiple uses occur after a move, only the first of these is flagged.
@@ -222,7 +224,8 @@ The check considers a variable to be reinitialized in the
following cases:
``unordered_multimap``.
- ``reset()`` is called on the variable and the variable is of type
- ``std::unique_ptr``, ``std::shared_ptr`` or ``std::weak_ptr``.
+ ``std::unique_ptr``, ``std::shared_ptr``, ``std::weak_ptr``,
+ ``std::optional``, or ``std::any``.
- A member function marked with the ``[[clang::reinitializes]]`` attribute is
called on the variable.
diff --git
a/clang-tools-extra/test/clang-tidy/checkers/bugprone/use-after-move.cpp
b/clang-tools-extra/test/clang-tidy/checkers/bugprone/use-after-move.cpp
index 6a4e3990e36dc5..c99bd0e4440858 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/use-after-move.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/use-after-move.cpp
@@ -33,6 +33,19 @@ struct weak_ptr {
bool expired() const;
};
+template <typename T>
+struct optional {
+ optional();
+ T& operator*();
+ const T& operator*() const;
+ void reset();
+};
+
+struct any {
+ any();
+ void reset();
+};
+
template <typename T1, typename T2>
struct pair {};
@@ -994,10 +1007,10 @@ void standardContainerAssignIsReinit() {
}
}
-// Resetting the standard smart pointer types using reset() is treated as a
+// Resetting the standard smart owning types using reset() is treated as a
// re-initialization. (We don't test std::weak_ptr<> because it can't be
// dereferenced directly.)
-void standardSmartPointerResetIsReinit() {
+void resetIsReinit() {
{
std::unique_ptr<A> ptr;
std::move(ptr);
@@ -1010,6 +1023,26 @@ void standardSmartPointerResetIsReinit() {
ptr.reset(new A);
*ptr;
}
+ {
+ std::optional<A> opt;
+ std::move(opt);
+ opt.reset();
+ std::optional<A> opt2 = opt;
+ (void)opt2;
+ }
+ {
+ std::optional<A> opt;
+ std::move(opt);
+ A val = *opt;
+ (void)val;
+ }
+ {
+ std::any a;
+ std::move(a);
+ a.reset();
+ std::any a2 = a;
+ (void)a2;
+ }
}
void reinitAnnotation() {
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
