https://github.com/usx95 updated
https://github.com/llvm/llvm-project/pull/111499
>From 7bfb78165fd605a928efbb39feb18b670210a66d Mon Sep 17 00:00:00 2001
From: Utkarsh Saxena <u...@google.com>
Date: Mon, 4 Nov 2024 12:06:08 +0000
Subject: [PATCH] Introduce [[clang::lifetime_capture_by]]
---
clang/include/clang/Basic/Attr.td | 40 +++++
clang/include/clang/Basic/DiagnosticGroups.td | 1 +
.../clang/Basic/DiagnosticSemaKinds.td | 15 ++
clang/include/clang/Sema/Sema.h | 10 ++
clang/lib/AST/TypePrinter.cpp | 9 +
clang/lib/Sema/CheckExprLifetime.cpp | 80 ++++++---
clang/lib/Sema/CheckExprLifetime.h | 27 ++-
clang/lib/Sema/SemaAttr.cpp | 36 ++++
clang/lib/Sema/SemaChecking.cpp | 47 ++++++
clang/lib/Sema/SemaDecl.cpp | 3 +
clang/lib/Sema/SemaDeclAttr.cpp | 103 ++++++++++++
clang/lib/Sema/SemaExpr.cpp | 4 +-
clang/lib/Sema/SemaInit.cpp | 2 +-
clang/lib/Sema/SemaOverload.cpp | 4 +-
.../lib/Sema/SemaTemplateInstantiateDecl.cpp | 1 -
clang/lib/Sema/SemaType.cpp | 13 ++
.../Sema/warn-lifetime-analysis-nocfg.cpp | 154 ++++++++++++++++++
.../test/SemaCXX/attr-lifetime-capture-by.cpp | 40 +++++
clang/test/SemaCXX/attr-lifetimebound.cpp | 4 +-
19 files changed, 559 insertions(+), 34 deletions(-)
create mode 100644 clang/test/SemaCXX/attr-lifetime-capture-by.cpp
diff --git a/clang/include/clang/Basic/Attr.td
b/clang/include/clang/Basic/Attr.td
index 156fbd1c4442eb..cb56ace6eaff47 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -1873,6 +1873,46 @@ def LifetimeBound : DeclOrTypeAttr {
let SimpleHandler = 1;
}
+def LifetimeCaptureBy : DeclOrTypeAttr {
+ let Spellings = [Clang<"lifetime_capture_by", 0>];
+ let Subjects = SubjectList<[ParmVar, ImplicitObjectParameter], ErrorDiag>;
+ let Args = [VariadicParamOrParamIdxArgument<"Params">];
+ let Documentation = [LifetimeBoundDocs];
+ let LangOpts = [CPlusPlus];
+
+ // let SimpleHandler = 1;
+ // let LateParsed = LateAttrParseStandard;
+ // let HasCustomParsing = 1;
+ // let ParseArgumentsAsUnevaluated = 1;
+
+ let AdditionalMembers = [{
+private:
+ SmallVector<IdentifierInfo*, 1> ArgIdents;
+ SmallVector<SourceLocation, 1> ArgLocs;
+
+public:
+ static constexpr int INVALID = -2;
+ static constexpr int UNKNOWN = -1;
+ static constexpr int GLOBAL = -1;
+ static constexpr int THIS = 0;
+
+ void setArgs(SmallVector<IdentifierInfo*, 1> Idents,
+ SmallVector<SourceLocation, 1> Locs) {
+ assert(Idents.size() == Locs.size());
+ assert(Idents.size() == params_Size);
+ ArgIdents = std::move(Idents);
+ ArgLocs = std::move(Locs);
+ }
+
+ const SmallVector<IdentifierInfo*, 1>& getArgIdents() const { return
ArgIdents; }
+ const SmallVector<SourceLocation, 1>& getArgLocs() const { return ArgLocs; }
+ void setParamIdx(size_t Idx, int Val) {
+ assert(Idx < params_Size);
+ params_[Idx] = Val;
+ }
+}];
+}
+
def TrivialABI : InheritableAttr {
// This attribute does not have a C [[]] spelling because it requires the
// CPlusPlus language option.
diff --git a/clang/include/clang/Basic/DiagnosticGroups.td
b/clang/include/clang/Basic/DiagnosticGroups.td
index 72eada50a56cc9..5209cd1eb795f3 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -453,6 +453,7 @@ def ShiftOpParentheses: DiagGroup<"shift-op-parentheses">;
def OverloadedShiftOpParentheses: DiagGroup<"overloaded-shift-op-parentheses">;
def DanglingAssignment: DiagGroup<"dangling-assignment">;
def DanglingAssignmentGsl : DiagGroup<"dangling-assignment-gsl">;
+def DanglingCapture : DiagGroup<"dangling-capture">;
def DanglingElse: DiagGroup<"dangling-else">;
def DanglingField : DiagGroup<"dangling-field">;
def DanglingInitializerList : DiagGroup<"dangling-initializer-list">;
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td
b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index d697e6d61afa9a..52a7e816aef5fc 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -3383,6 +3383,18 @@ def err_callback_callee_is_variadic : Error<
"'callback' attribute callee may not be variadic">;
def err_callback_implicit_this_not_available : Error<
"'callback' argument at position %0 references unavailable implicit 'this'">;
+
+def err_capture_by_attribute_multiple : Error<
+ "multiple 'lifetime_capture' attributes specified">;
+def err_capture_by_attribute_no_entity : Error<
+ "'lifetime_capture_by' attribute specifies no capturing entity">;
+def err_capture_by_implicit_this_not_available : Error<
+ "'lifetime_capture_by' argument references unavailable implicit 'this'">;
+def err_capture_by_attribute_argument_unknown : Error<
+ "'lifetime_capture_by' attribute argument %0 is not a known function
parameter"
+ ". Must be a function parameter of one of 'this', 'global' or 'unknown'">;
+def err_capture_by_references_itself : Error<"'lifetime_capture_by' argument
references itself">;
+
def err_init_method_bad_return_type : Error<
"init methods must return an object pointer type, not %0">;
def err_attribute_invalid_size : Error<
@@ -10198,6 +10210,9 @@ def warn_dangling_pointer_assignment : Warning<
"object backing %select{|the pointer }0%1 "
"will be destroyed at the end of the full-expression">,
InGroup<DanglingAssignment>;
+def warn_dangling_reference_captured : Warning<
+ "object captured by '%0' will be destroyed at the end of the
full-expression">,
+ InGroup<DanglingCapture>;
// For non-floating point, expressions of the form x == x or x != x
// should result in a warning, since these always evaluate to a constant.
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 93d98e1cbb9c81..2378e99e71f220 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -1757,9 +1757,16 @@ class Sema final : public SemaBase {
/// Add [[clang:::lifetimebound]] attr for std:: functions and methods.
void inferLifetimeBoundAttribute(FunctionDecl *FD);
+ /// Add [[clang:::lifetime_capture(this)]] to std:: methods.
+ void inferLifetimeCaptureByAttribute(FunctionDecl *FD);
+
/// Add [[gsl::Pointer]] attributes for std:: types.
void inferGslPointerAttribute(TypedefNameDecl *TD);
+ LifetimeCaptureByAttr *ParseLifetimeCaptureByAttr(const ParsedAttr &AL,
+ StringRef ParamName);
+ void LazyProcessLifetimeCaptureByParams(FunctionDecl *FD);
+
/// Add _Nullable attributes for std:: types.
void inferNullableClassAttribute(CXXRecordDecl *CRD);
@@ -2315,6 +2322,9 @@ class Sema final : public SemaBase {
bool BuiltinVectorMath(CallExpr *TheCall, QualType &Res, bool FPOnly =
false);
bool BuiltinVectorToScalarMath(CallExpr *TheCall);
+ void checkLifetimeCaptureBy(FunctionDecl *FDecl, bool IsMemberFunction,
+ const Expr *ThisArg, ArrayRef<const Expr *>
Args);
+
/// Handles the checks for format strings, non-POD arguments to vararg
/// functions, NULL arguments passed to non-NULL parameters, diagnose_if
/// attributes and AArch64 SME attributes.
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index 6d8db5cf4ffd22..ce37b40738da3b 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -12,6 +12,7 @@
#include "clang/AST/ASTContext.h"
#include "clang/AST/Attr.h"
+#include "clang/AST/Attrs.inc"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclBase.h"
#include "clang/AST/DeclCXX.h"
@@ -25,6 +26,7 @@
#include "clang/AST/TextNodeDumper.h"
#include "clang/AST/Type.h"
#include "clang/Basic/AddressSpaces.h"
+#include "clang/Basic/AttrKinds.h"
#include "clang/Basic/ExceptionSpecificationType.h"
#include "clang/Basic/IdentifierTable.h"
#include "clang/Basic/LLVM.h"
@@ -1909,6 +1911,12 @@ void TypePrinter::printAttributedAfter(const
AttributedType *T,
OS << " [[clang::lifetimebound]]";
return;
}
+ if (T->getAttrKind() == attr::LifetimeCaptureBy) {
+ // FIXME: Print the attribute arguments once we have a way to retrieve
these
+ // here.
+ OS << " [[clang::lifetime_capture_by(...)";
+ return;
+ }
// The printing of the address_space attribute is handled by the qualifier
// since it is still stored in the qualifier. Return early to prevent
printing
@@ -1976,6 +1984,7 @@ void TypePrinter::printAttributedAfter(const
AttributedType *T,
case attr::SizedBy:
case attr::SizedByOrNull:
case attr::LifetimeBound:
+ case attr::LifetimeCaptureBy:
case attr::TypeNonNull:
case attr::TypeNullable:
case attr::TypeNullableResult:
diff --git a/clang/lib/Sema/CheckExprLifetime.cpp
b/clang/lib/Sema/CheckExprLifetime.cpp
index a1a402b4a2b530..ff72ed8bfc58ec 100644
--- a/clang/lib/Sema/CheckExprLifetime.cpp
+++ b/clang/lib/Sema/CheckExprLifetime.cpp
@@ -7,7 +7,10 @@
//===----------------------------------------------------------------------===//
#include "CheckExprLifetime.h"
+#include "clang/AST/Attrs.inc"
#include "clang/AST/Decl.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/DeclTemplate.h"
#include "clang/AST/Expr.h"
#include "clang/Basic/DiagnosticSema.h"
#include "clang/Sema/Initialization.h"
@@ -45,10 +48,14 @@ enum LifetimeKind {
/// a default member initializer), the program is ill-formed.
LK_MemInitializer,
- /// The lifetime of a temporary bound to this entity probably ends too soon,
+ /// The lifetime of a temporary bound to this entity may end too soon,
/// because the entity is a pointer and we assign the address of a temporary
/// object to it.
LK_Assignment,
+
+ /// The lifetime of a temporary bound to this entity may end too soon,
+ /// because the entity may capture the reference to a temporary object.
+ LK_LifetimeCapture,
};
using LifetimeResult =
llvm::PointerIntPair<const InitializedEntity *, 3, LifetimeKind>;
@@ -193,6 +200,7 @@ struct IndirectLocalPathEntry {
VarInit,
LValToRVal,
LifetimeBoundCall,
+ LifetimeCapture,
TemporaryCopy,
LambdaCaptureInit,
GslReferenceInit,
@@ -249,9 +257,12 @@ static void
visitLocalsRetainedByReferenceBinding(IndirectLocalPath &Path,
LocalVisitor Visit);
template <typename T> static bool isRecordWithAttr(QualType Type) {
- if (auto *RD = Type->getAsCXXRecordDecl())
- return RD->hasAttr<T>();
- return false;
+ CXXRecordDecl *RD = Type.getNonReferenceType()->getAsCXXRecordDecl();
+ if (!RD)
+ return false;
+ if (auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(RD))
+ RD = CTSD->getSpecializedTemplate()->getTemplatedDecl();
+ return RD->hasAttr<T>();
}
// Decl::isInStdNamespace will return false for iterators in some STL
@@ -1049,6 +1060,7 @@ static SourceRange nextPathEntryRange(const
IndirectLocalPath &Path, unsigned I,
case IndirectLocalPathEntry::AddressOf:
case IndirectLocalPathEntry::LValToRVal:
case IndirectLocalPathEntry::LifetimeBoundCall:
+ case IndirectLocalPathEntry::LifetimeCapture:
case IndirectLocalPathEntry::TemporaryCopy:
case IndirectLocalPathEntry::GslReferenceInit:
case IndirectLocalPathEntry::GslPointerInit:
@@ -1082,6 +1094,7 @@ static bool pathOnlyHandlesGslPointer(const
IndirectLocalPath &Path) {
case IndirectLocalPathEntry::VarInit:
case IndirectLocalPathEntry::AddressOf:
case IndirectLocalPathEntry::LifetimeBoundCall:
+ case IndirectLocalPathEntry::LifetimeCapture:
continue;
case IndirectLocalPathEntry::GslPointerInit:
case IndirectLocalPathEntry::GslReferenceInit:
@@ -1102,11 +1115,11 @@ static bool
isAssignmentOperatorLifetimeBound(CXXMethodDecl *CMD) {
}
static bool shouldRunGSLAssignmentAnalysis(const Sema &SemaRef,
- const AssignedEntity &Entity) {
+ const CapturingEntity &Entity) {
bool EnableGSLAssignmentWarnings = !SemaRef.getDiagnostics().isIgnored(
diag::warn_dangling_lifetime_pointer_assignment, SourceLocation());
return (EnableGSLAssignmentWarnings &&
- (isRecordWithAttr<PointerAttr>(Entity.LHS->getType()) ||
+ (isRecordWithAttr<PointerAttr>(Entity.Expression->getType()) ||
isAssignmentOperatorLifetimeBound(Entity.AssignmentOperator)));
}
@@ -1114,9 +1127,10 @@ static void checkExprLifetimeImpl(Sema &SemaRef,
const InitializedEntity *InitEntity,
const InitializedEntity *ExtendingEntity,
LifetimeKind LK,
- const AssignedEntity *AEntity, Expr *Init) {
- assert((AEntity && LK == LK_Assignment) ||
- (InitEntity && LK != LK_Assignment));
+ const CapturingEntity *CEntity, Expr *Init) {
+ assert(InitEntity || CEntity);
+ assert(!CEntity || LK == LK_Assignment || LK == LK_LifetimeCapture);
+ assert(!InitEntity || LK != LK_Assignment);
// If this entity doesn't have an interesting lifetime, don't bother looking
// for temporaries within its initializer.
if (LK == LK_FullExpression)
@@ -1199,6 +1213,17 @@ static void checkExprLifetimeImpl(Sema &SemaRef,
break;
}
+ case LK_LifetimeCapture: {
+ if (!MTE)
+ return false;
+ assert(shouldLifetimeExtendThroughPath(Path) ==
+ PathLifetimeKind::NoExtend &&
+ "No lifetime extension in function calls");
+ SemaRef.Diag(DiagLoc, diag::warn_dangling_reference_captured)
+ << CEntity->Expression << DiagRange;
+ return false;
+ }
+
case LK_Assignment: {
if (!MTE || pathContainsInit(Path))
return false;
@@ -1207,10 +1232,10 @@ static void checkExprLifetimeImpl(Sema &SemaRef,
"No lifetime extension for assignments");
if (IsGslPtrValueFromGslTempOwner)
SemaRef.Diag(DiagLoc, diag::warn_dangling_lifetime_pointer_assignment)
- << AEntity->LHS << DiagRange;
+ << CEntity->Expression << DiagRange;
else
SemaRef.Diag(DiagLoc, diag::warn_dangling_pointer_assignment)
- << AEntity->LHS->getType()->isPointerType() << AEntity->LHS
+ << CEntity->Expression->getType()->isPointerType() <<
CEntity->Expression
<< DiagRange;
return false;
}
@@ -1359,6 +1384,7 @@ static void checkExprLifetimeImpl(Sema &SemaRef,
break;
case IndirectLocalPathEntry::LifetimeBoundCall:
+ case IndirectLocalPathEntry::LifetimeCapture:
case IndirectLocalPathEntry::TemporaryCopy:
case IndirectLocalPathEntry::GslPointerInit:
case IndirectLocalPathEntry::GslReferenceInit:
@@ -1412,17 +1438,27 @@ static void checkExprLifetimeImpl(Sema &SemaRef,
return false;
};
+ bool HasReferenceBinding = Init->isGLValue();
llvm::SmallVector<IndirectLocalPathEntry, 8> Path;
if (LK == LK_Assignment &&
- shouldRunGSLAssignmentAnalysis(SemaRef, *AEntity)) {
+ shouldRunGSLAssignmentAnalysis(SemaRef, *CEntity)) {
Path.push_back(
- {isAssignmentOperatorLifetimeBound(AEntity->AssignmentOperator)
+ {isAssignmentOperatorLifetimeBound(CEntity->AssignmentOperator)
? IndirectLocalPathEntry::LifetimeBoundCall
: IndirectLocalPathEntry::GslPointerAssignment,
Init});
+ } else if (LK == LK_LifetimeCapture) {
+ Path.push_back({IndirectLocalPathEntry::LifetimeCapture, Init});
+ if (isRecordWithAttr<PointerAttr>(Init->getType()))
+ HasReferenceBinding = false;
+ // Skip the top MaterializeTemoraryExpr if it is temporary object of the
+ // pointer-like type itself.
+ if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(Init);
+ MTE && isPointerLikeType(Init->getType()))
+ Init = MTE->getSubExpr();
}
- if (Init->isGLValue())
+ if (HasReferenceBinding)
visitLocalsRetainedByReferenceBinding(Path, Init, RK_ReferenceBinding,
TemporaryVisitor);
else
@@ -1432,7 +1468,7 @@ static void checkExprLifetimeImpl(Sema &SemaRef,
/*RevisitSubinits=*/!InitEntity);
}
-void checkExprLifetime(Sema &SemaRef, const InitializedEntity &Entity,
+void checkInitLifetime(Sema &SemaRef, const InitializedEntity &Entity,
Expr *Init) {
auto LTResult = getEntityLifetime(&Entity);
LifetimeKind LK = LTResult.getInt();
@@ -1447,12 +1483,12 @@ void checkExprLifetimeMustTailArg(Sema &SemaRef,
/*AEntity*/ nullptr, Init);
}
-void checkExprLifetime(Sema &SemaRef, const AssignedEntity &Entity,
- Expr *Init) {
+void checkAssignmentLifetime(Sema &SemaRef, const CapturingEntity &Entity,
+ Expr *RHS) {
bool EnableDanglingPointerAssignment = !SemaRef.getDiagnostics().isIgnored(
diag::warn_dangling_pointer_assignment, SourceLocation());
bool RunAnalysis = (EnableDanglingPointerAssignment &&
- Entity.LHS->getType()->isPointerType()) ||
+ Entity.Expression->getType()->isPointerType()) ||
shouldRunGSLAssignmentAnalysis(SemaRef, Entity);
if (!RunAnalysis)
@@ -1460,7 +1496,13 @@ void checkExprLifetime(Sema &SemaRef, const
AssignedEntity &Entity,
checkExprLifetimeImpl(SemaRef, /*InitEntity=*/nullptr,
/*ExtendingEntity=*/nullptr, LK_Assignment, &Entity,
- Init);
+ RHS);
}
+void checkCaptureLifetime(Sema &SemaRef, const CapturingEntity &Entity,
+ Expr *Captured) {
+ checkExprLifetimeImpl(SemaRef, /*InitEntity=*/nullptr,
+ /*ExtendingEntity=*/nullptr, LK_LifetimeCapture,
+ &Entity, Captured);
+}
} // namespace clang::sema
diff --git a/clang/lib/Sema/CheckExprLifetime.h
b/clang/lib/Sema/CheckExprLifetime.h
index 903f312f3533e5..976260d40e46bf 100644
--- a/clang/lib/Sema/CheckExprLifetime.h
+++ b/clang/lib/Sema/CheckExprLifetime.h
@@ -18,29 +18,42 @@
namespace clang::sema {
-/// Describes an entity that is being assigned.
-struct AssignedEntity {
- // The left-hand side expression of the assignment.
- Expr *LHS = nullptr;
+struct CapturingEntity {
+ // The expression of the entity which captures another entity.
+ // For example:
+ // 1. In an assignment, this would be the left-hand side expression.
+ // std::string_view sv;
+ // sv = std::string(); // Here 'sv' is the 'Entity'.
+ //
+ // 2. In an function call involving a lifetime capture, this would be the
+ // argument capturing the lifetime of another argument.
+ // void addToSet(std::string_view s [[clang::lifetime_capture_by(sv)]],
+ // set<std::string_view>& setsv);
+ // set<std::string_view> ssv;
+ // addToSet(std::string(), ssv); // Here 'ssv' is the 'Entity'.
+ Expr *Expression = nullptr;
CXXMethodDecl *AssignmentOperator = nullptr;
};
/// Check that the lifetime of the given expr (and its subobjects) is
/// sufficient for initializing the entity, and perform lifetime extension
/// (when permitted) if not.
-void checkExprLifetime(Sema &SemaRef, const InitializedEntity &Entity,
+void checkInitLifetime(Sema &SemaRef, const InitializedEntity &Entity,
Expr *Init);
/// Check that the lifetime of the given expr (and its subobjects) is
/// sufficient for assigning to the entity.
-void checkExprLifetime(Sema &SemaRef, const AssignedEntity &Entity, Expr
*Init);
+void checkAssignmentLifetime(Sema &SemaRef, const CapturingEntity &Entity,
+ Expr *RHS);
+
+void checkCaptureLifetime(Sema &SemaRef, const CapturingEntity &Entity,
+ Expr *Captured);
/// Check that the lifetime of the given expr (and its subobjects) is
/// sufficient, assuming that it is passed as an argument to a musttail
/// function.
void checkExprLifetimeMustTailArg(Sema &SemaRef,
const InitializedEntity &Entity, Expr *Init);
-
} // namespace clang::sema
#endif // LLVM_CLANG_SEMA_CHECK_EXPR_LIFETIME_H
diff --git a/clang/lib/Sema/SemaAttr.cpp b/clang/lib/Sema/SemaAttr.cpp
index 68a8dfaf1f6183..2c7f8145945567 100644
--- a/clang/lib/Sema/SemaAttr.cpp
+++ b/clang/lib/Sema/SemaAttr.cpp
@@ -13,6 +13,8 @@
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/Attr.h"
+#include "clang/AST/Attrs.inc"
+#include "clang/AST/DeclCXX.h"
#include "clang/AST/Expr.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Lex/Preprocessor.h"
@@ -269,6 +271,40 @@ void Sema::inferLifetimeBoundAttribute(FunctionDecl *FD) {
}
}
+static bool IsPointerLikeType(QualType QT) {
+ QT = QT.getNonReferenceType();
+ // if (QT->isPointerType())
+ // return true;
+ auto *RD = QT->getAsCXXRecordDecl();
+ if (!RD)
+ return false;
+ RD = RD->getCanonicalDecl();
+ if (auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(RD))
+ RD = CTSD->getSpecializedTemplate()->getTemplatedDecl();
+ return RD->hasAttr<PointerAttr>();
+}
+
+void Sema::inferLifetimeCaptureByAttribute(FunctionDecl *FD) {
+ if (!FD)
+ return;
+ auto *MD = dyn_cast<CXXMethodDecl>(FD);
+ if (!MD || !MD->getIdentifier() || !MD->getParent()->isInStdNamespace())
+ return;
+ static const llvm::StringSet<> CapturingMethods{"insert", "push",
+ "push_front", "push_back"};
+ if (!CapturingMethods.contains(MD->getName()))
+ return;
+ for (ParmVarDecl *PVD : MD->parameters()) {
+ if (PVD->hasAttr<LifetimeCaptureByAttr>())
+ return;
+ if (IsPointerLikeType(PVD->getType())) {
+ int CaptureByThis[] = {LifetimeCaptureByAttr::THIS};
+ PVD->addAttr(
+ LifetimeCaptureByAttr::CreateImplicit(Context, CaptureByThis, 1));
+ }
+ }
+}
+
void Sema::inferNullableClassAttribute(CXXRecordDecl *CRD) {
static const llvm::StringSet<> Nullable{
"auto_ptr", "shared_ptr", "unique_ptr", "exception_ptr",
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index dae271c1ff5001..0fb3dd8e254306 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -11,10 +11,12 @@
//
//===----------------------------------------------------------------------===//
+#include "CheckExprLifetime.h"
#include "clang/AST/APValue.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Attr.h"
#include "clang/AST/AttrIterator.h"
+#include "clang/AST/Attrs.inc"
#include "clang/AST/CharUnits.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclBase.h"
@@ -3223,6 +3225,49 @@ void Sema::CheckArgAlignment(SourceLocation Loc,
NamedDecl *FDecl,
<< ParamName << (FDecl != nullptr) << FDecl;
}
+void Sema::checkLifetimeCaptureBy(FunctionDecl *FD, bool IsMemberFunction,
+ const Expr *ThisArg,
+ ArrayRef<const Expr *> Args) {
+ auto GetArgAt = [&](int Idx) {
+ if (IsMemberFunction && Idx == 0)
+ return const_cast<Expr *>(ThisArg);
+ return const_cast<Expr *>(Args[Idx - int(IsMemberFunction)]);
+ };
+ for (unsigned I = 0; I < FD->getNumParams(); ++I) {
+ auto *CapturedByAttr =
+ FD->getParamDecl(I)->getAttr<LifetimeCaptureByAttr>();
+ if (!CapturedByAttr)
+ continue;
+ for (int CapturingParamIdx : CapturedByAttr->params()) {
+ Expr *Capturing = GetArgAt(CapturingParamIdx);
+ Expr *Captured = GetArgAt(I + IsMemberFunction);
+ CapturingEntity CE{Capturing};
+ // Ensure that 'Captured' outlives the 'Capturing' entity.
+ checkCaptureLifetime(*this, CE, Captured);
+ }
+ }
+ // Check when the 'this' object is captured.
+ if (IsMemberFunction) {
+ TypeSourceInfo *TSI = FD->getTypeSourceInfo();
+ if (!TSI)
+ return;
+ AttributedTypeLoc ATL;
+ for (TypeLoc TL = TSI->getTypeLoc();
+ (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
+ TL = ATL.getModifiedLoc()) {
+ auto *CapturedByAttr = ATL.getAttrAs<LifetimeCaptureByAttr>();
+ if (!CapturedByAttr)
+ continue;
+ Expr *Captured = GetArgAt(0);
+ for (int CapturingParamIdx : CapturedByAttr->params()) {
+ Expr *Capturing = GetArgAt(CapturingParamIdx);
+ CapturingEntity CE{Capturing};
+ checkCaptureLifetime(*this, CE, Captured);
+ }
+ }
+ }
+}
+
void Sema::checkCall(NamedDecl *FDecl, const FunctionProtoType *Proto,
const Expr *ThisArg, ArrayRef<const Expr *> Args,
bool IsMemberFunction, SourceLocation Loc,
@@ -3264,6 +3309,8 @@ void Sema::checkCall(NamedDecl *FDecl, const
FunctionProtoType *Proto,
}
}
+ if (FD)
+ checkLifetimeCaptureBy(FD, IsMemberFunction, ThisArg, Args);
if (FDecl || Proto) {
CheckNonNullArguments(*this, FDecl, Proto, Args, Loc);
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 1aa3e8edfe1b13..9c0530febf3d92 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11882,6 +11882,7 @@ bool Sema::CheckFunctionDeclaration(Scope *S,
FunctionDecl *NewFD,
NamedDecl *OldDecl = nullptr;
bool MayNeedOverloadableChecks = false;
+ inferLifetimeCaptureByAttribute(NewFD);
// Merge or overload the declaration with an existing declaration of
// the same name, if appropriate.
if (!Previous.empty()) {
@@ -16655,7 +16656,9 @@ void Sema::AddKnownFunctionAttributes(FunctionDecl *FD)
{
}
}
+ LazyProcessLifetimeCaptureByParams(FD);
inferLifetimeBoundAttribute(FD);
+ inferLifetimeCaptureByAttribute(FD);
AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(FD);
// If C++ exceptions are enabled but we are told extern "C" functions cannot
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 601c6f2eef1d9c..b969c6462faa1a 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -14,6 +14,7 @@
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTMutationListener.h"
#include "clang/AST/CXXInheritance.h"
+#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
@@ -3867,6 +3868,105 @@ static void handleCallbackAttr(Sema &S, Decl *D, const
ParsedAttr &AL) {
S.Context, AL, EncodingIndices.data(), EncodingIndices.size()));
}
+LifetimeCaptureByAttr *Sema::ParseLifetimeCaptureByAttr(const ParsedAttr &AL,
+ StringRef ParamName) {
+ // Atleast one capture by is required.
+ if (AL.getNumArgs() == 0) {
+ Diag(AL.getLoc(), diag::err_capture_by_attribute_no_entity)
+ << AL.getRange();
+ return nullptr;
+ }
+ SmallVector<IdentifierInfo *, 1> ParamIdents;
+ SmallVector<SourceLocation, 1> ParamLocs;
+ for (unsigned I = 0; I < AL.getNumArgs(); ++I) {
+ if (AL.isArgExpr(I)) {
+ Expr *E = AL.getArgAsExpr(I);
+ Diag(E->getExprLoc(), diag::err_capture_by_attribute_argument_unknown)
+ << E << E->getExprLoc();
+ continue;
+ }
+ assert(AL.isArgIdent(I));
+ IdentifierLoc *IdLoc = AL.getArgAsIdent(I);
+ if (IdLoc->Ident->getName() == ParamName) {
+ Diag(IdLoc->Loc, diag::err_capture_by_references_itself) << IdLoc->Loc;
+ continue;
+ }
+ ParamIdents.push_back(IdLoc->Ident);
+ ParamLocs.push_back(IdLoc->Loc);
+ }
+ SmallVector<int, 1> FakeParamIndices(ParamIdents.size(),
+ LifetimeCaptureByAttr::INVALID);
+ LifetimeCaptureByAttr *CapturedBy = ::new (Context) LifetimeCaptureByAttr(
+ Context, AL, FakeParamIndices.data(), FakeParamIndices.size());
+ CapturedBy->setArgs(std::move(ParamIdents), std::move(ParamLocs));
+ return CapturedBy;
+}
+
+static void HandleLifetimeCaptureByAttr(Sema &S, Decl *D,
+ const ParsedAttr &AL) {
+ // Do not allow multiple attributes.
+ if (D->hasAttr<LifetimeCaptureByAttr>()) {
+ S.Diag(AL.getLoc(), diag::err_capture_by_attribute_multiple)
+ << AL.getRange();
+ return;
+ }
+ auto *PVD = dyn_cast<ParmVarDecl>(D);
+ assert(PVD);
+ auto *CaptureByAttr = S.ParseLifetimeCaptureByAttr(AL, PVD->getName());
+ if (CaptureByAttr)
+ D->addAttr(CaptureByAttr);
+}
+
+void Sema::LazyProcessLifetimeCaptureByParams(FunctionDecl *FD) {
+ bool HasImplicitThisParam = isInstanceMethod(FD);
+
+ llvm::StringMap<int> NameIdxMapping;
+ NameIdxMapping["global"] = LifetimeCaptureByAttr::GLOBAL;
+ NameIdxMapping["unknown"] = LifetimeCaptureByAttr::UNKNOWN;
+ int Idx = 0;
+ if (HasImplicitThisParam) {
+ NameIdxMapping["this"] = 0;
+ Idx++;
+ }
+ for (const ParmVarDecl *PVD : FD->parameters())
+ NameIdxMapping[PVD->getName()] = Idx++;
+ auto HandleCaptureBy = [&](LifetimeCaptureByAttr *CapturedBy) {
+ if (!CapturedBy)
+ return;
+ const auto &Entities = CapturedBy->getArgIdents();
+ for (size_t I = 0; I < Entities.size(); ++I) {
+ StringRef Name = Entities[I]->getName();
+ auto It = NameIdxMapping.find(Name);
+ if (It == NameIdxMapping.end()) {
+ auto Loc = CapturedBy->getArgLocs()[I];
+ if (!HasImplicitThisParam && Name == "this")
+ Diag(Loc, diag::err_capture_by_implicit_this_not_available) << Loc;
+ else
+ Diag(Loc, diag::err_capture_by_attribute_argument_unknown)
+ << Entities[I] << Loc;
+ continue;
+ }
+ CapturedBy->setParamIdx(I, It->second);
+ }
+ };
+ for (ParmVarDecl *PVD : FD->parameters())
+ HandleCaptureBy(PVD->getAttr<LifetimeCaptureByAttr>());
+ if (!HasImplicitThisParam)
+ return;
+ TypeSourceInfo *TSI = FD->getTypeSourceInfo();
+ if (!TSI)
+ return;
+ AttributedTypeLoc ATL;
+ for (TypeLoc TL = TSI->getTypeLoc();
+ (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
+ TL = ATL.getModifiedLoc()) {
+ auto *A = ATL.getAttrAs<LifetimeCaptureByAttr>();
+ if (!A)
+ continue;
+ HandleCaptureBy(const_cast<LifetimeCaptureByAttr *>(A));
+ }
+}
+
static bool isFunctionLike(const Type &T) {
// Check for explicit function types.
// 'called_once' is only supported in Objective-C and it has
@@ -6632,6 +6732,9 @@ ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
const ParsedAttr &AL,
case ParsedAttr::AT_Callback:
handleCallbackAttr(S, D, AL);
break;
+ case ParsedAttr::AT_LifetimeCaptureBy:
+ HandleLifetimeCaptureByAttr(S, D, AL);
+ break;
case ParsedAttr::AT_CalledOnce:
handleCalledOnceAttr(S, D, AL);
break;
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 7f3cff1054aeed..b5484a8cef6bcc 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -13741,8 +13741,8 @@ QualType Sema::CheckAssignmentOperands(Expr *LHSExpr,
ExprResult &RHS,
CheckForNullPointerDereference(*this, LHSExpr);
- AssignedEntity AE{LHSExpr};
- checkExprLifetime(*this, AE, RHS.get());
+ CapturingEntity AE{LHSExpr};
+ checkAssignmentLifetime(*this, AE, RHS.get());
if (getLangOpts().CPlusPlus20 && LHSType.isVolatileQualified()) {
if (CompoundType.isNull()) {
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index e2a59f63ccf589..d674779fea363d 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -7401,7 +7401,7 @@ PerformConstructorInitialization(Sema &S,
void Sema::checkInitializerLifetime(const InitializedEntity &Entity,
Expr *Init) {
- return sema::checkExprLifetime(*this, Entity, Init);
+ return sema::checkInitLifetime(*this, Entity, Init);
}
static void DiagnoseNarrowingInInitList(Sema &S,
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 4aeceba128b29b..d937ce6e377a42 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -14811,8 +14811,8 @@ ExprResult Sema::CreateOverloadedBinOp(SourceLocation
OpLoc,
// Check for a self move.
DiagnoseSelfMove(Args[0], Args[1], OpLoc);
// lifetime check.
- checkExprLifetime(
- *this, AssignedEntity{Args[0], dyn_cast<CXXMethodDecl>(FnDecl)},
+ checkAssignmentLifetime(
+ *this, CapturingEntity{Args[0], dyn_cast<CXXMethodDecl>(FnDecl)},
Args[1]);
}
if (ImplicitThis) {
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 3e948232057afe..89a419ea90f394 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -4961,7 +4961,6 @@ void Sema::InstantiateFunctionDefinition(SourceLocation
PointOfInstantiation,
bool AtEndOfTU) {
if (Function->isInvalidDecl() || isa<CXXDeductionGuideDecl>(Function))
return;
-
// Never instantiate an explicit specialization except if it is a class scope
// explicit specialization.
TemplateSpecializationKind TSK =
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index e526a11973975d..1aa7f94dc18e47 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8606,6 +8606,15 @@ static void HandleLifetimeBoundAttr(TypeProcessingState
&State,
}
}
+static void HandleLifetimeCaptureByAttr(TypeProcessingState &State,
+ QualType &CurType, ParsedAttr &PA) {
+ if (State.getDeclarator().isDeclarationOfFunction()) {
+ auto *Attr = State.getSema().ParseLifetimeCaptureByAttr(PA, "this");
+ if (Attr)
+ CurType = State.getAttributedType(Attr, CurType, CurType);
+ }
+}
+
static void HandleHLSLParamModifierAttr(TypeProcessingState &State,
QualType &CurType,
const ParsedAttr &Attr, Sema &S) {
@@ -8767,6 +8776,10 @@ static void processTypeAttrs(TypeProcessingState &state,
QualType &type,
if (TAL == TAL_DeclChunk)
HandleLifetimeBoundAttr(state, type, attr);
break;
+ case ParsedAttr::AT_LifetimeCaptureBy:
+ if (TAL == TAL_DeclChunk)
+ HandleLifetimeCaptureByAttr(state, type, attr);
+ break;
case ParsedAttr::AT_NoDeref: {
// FIXME: `noderef` currently doesn't work correctly in [[]] syntax.
diff --git a/clang/test/Sema/warn-lifetime-analysis-nocfg.cpp
b/clang/test/Sema/warn-lifetime-analysis-nocfg.cpp
index 6a2af01ea5116c..39a8d4d98e2f7e 100644
--- a/clang/test/Sema/warn-lifetime-analysis-nocfg.cpp
+++ b/clang/test/Sema/warn-lifetime-analysis-nocfg.cpp
@@ -177,8 +177,12 @@ struct vector {
template<typename InputIterator>
vector(InputIterator first, InputIterator __last);
+ void push_back(const T&);
+ void push_back(T&&);
T &at(int n);
+
+ void insert(iterator, T&&);
};
template<typename T>
@@ -793,3 +797,153 @@ void test13() {
}
} // namespace GH100526
+
+
+namespace lifetime_capture_by {
+struct S {
+ const int *x;
+ void captureInt(const int&x [[clang::lifetime_capture_by(this)]]) { this->x
= &x; }
+ void captureSV(std::string_view sv [[clang::lifetime_capture_by(this)]]);
+};
+///////////////////////////
+// Detect dangling cases.
+///////////////////////////
+void captureInt(const int&x [[clang::lifetime_capture_by(s)]], S&s);
+void captureRValInt(int&&x [[clang::lifetime_capture_by(s)]], S&s);
+void noCaptureInt(int x [[clang::lifetime_capture_by(s)]], S&s);
+
+std::string_view substr(const std::string& s [[clang::lifetimebound]]);
+std::string_view strcopy(const std::string& s);
+
+void captureSV(std::string_view x [[clang::lifetime_capture_by(s)]], S&s);
+void captureRValSV(std::string_view&& x [[clang::lifetime_capture_by(s)]],
S&s);
+void noCaptureSV(std::string_view x, S&s);
+
+void captureS(const std::string& x [[clang::lifetime_capture_by(s)]], S&s);
+void captureRValS(std::string&& x [[clang::lifetime_capture_by(s)]], S&s);
+
+const std::string* getPointerLB(const std::string& s[[clang::lifetimebound]]);
+const std::string* getPointerNoLB(const std::string& s);
+void capturePointer(const std::string* x [[clang::lifetime_capture_by(s)]],
S&s);
+
+struct ThisIsCaptured {
+ void capture(S& s) [[clang::lifetime_capture_by(s)]];
+ void bar(S& s) [[clang::lifetime_capture_by(abcd)]]; // expected-error
{{'lifetime_capture_by' attribute argument 'abcd' is not a known function
parameter}}
+ void baz(S& s) [[clang::lifetime_capture_by(this)]]; // expected-error
{{'lifetime_capture_by' argument references itself}}
+};
+
+void use() {
+ std::string_view local_sv;
+ std::string local_s;
+ S s;
+ // Capture an 'int'.
+ int local;
+ captureInt(1, // expected-warning {{object captured by 's' will be destroyed
at the end of the full-expression}}
+ s);
+ captureRValInt(1, s); // expected-warning {{object captured by 's'}}
+ captureInt(local, s);
+
+ noCaptureInt(1, s);
+ noCaptureInt(local, s);
+
+ // Capture lifetimebound pointer.
+ capturePointer(getPointerLB(std::string()), s); // expected-warning {{object
captured by 's'}}
+ capturePointer(getPointerLB(*getPointerLB(std::string())), s); //
expected-warning {{object captured by 's'}}
+ capturePointer(getPointerNoLB(std::string()), s);
+
+ // Capture using std::string_view.
+ captureSV(local_sv, s);
+ captureSV(std::string(), // expected-warning {{object captured by 's'}}
+ s);
+ captureSV(substr(
+ std::string() // expected-warning {{object captured by 's'}}
+ ), s);
+ captureSV(substr(local_s), s);
+ captureSV(strcopy(std::string()), s);
+
+ captureRValSV(std::move(local_sv), s);
+ captureRValSV(std::string(), s); // expected-warning {{object captured by
's'}}
+ captureRValSV(std::string_view{"abcd"}, s);
+ captureRValSV(substr(local_s), s);
+ captureRValSV(substr(std::string()), s); // expected-warning {{object
captured by 's'}}
+ captureRValSV(strcopy(std::string()), s);
+
+ noCaptureSV(local_sv, s);
+ noCaptureSV(std::string(), s);
+ noCaptureSV(substr(std::string()), s);
+
+ // Capture using std::string.
+ captureS(std::string(), s); // expected-warning {{object captured by 's'}}
+ captureS(local_s, s);
+ captureRValS(std::move(local_s), s);
+ captureRValS(std::string(), s); // expected-warning {{object captured by
's'}}
+
+ // Member functions.
+ s.captureInt(1); // expected-warning {{object captured by 's'}}
+ s.captureSV(std::string()); // expected-warning {{object captured by 's'}}
+ s.captureSV(substr(std::string())); // expected-warning {{object captured by
's'}}
+ s.captureSV(strcopy(std::string()));
+
+ // This is captured.
+ ThisIsCaptured{}.capture(s); // expected-warning {{object captured by 's'}}
+ ThisIsCaptured TIS;
+ TIS.capture(s);
+}
+
+class [[gsl::Pointer()]] my_string_view : public std::string_view {};
+class my_string_view_not_pointer : public std::string_view {};
+std::optional<std::string_view> getOptionalSV();
+std::optional<std::string> getOptionalS();
+std::optional<my_string_view> getOptionalMySV();
+std::optional<my_string_view_not_pointer> getOptionalMySVNotP();
+my_string_view getMySV();
+my_string_view_not_pointer getMySVNotP();
+
+// Infer attribute in STL container of pointers.
+void container_of_pointers() {
+ std::string local;
+ std::vector<std::string> vs;
+ vs.push_back(std::string()); // Ok.
+ vs.insert(vs.begin(), std::string()); // Ok.
+
+ std::vector<std::string_view> vsv;
+ vsv.push_back(std::string()); // expected-warning {{object captured by
'vsv'}}
+ vsv.insert(vsv.begin(), std::string()); // expected-warning {{object
captured by 'vsv'}}
+
+ std::vector<const std::string*> vp;
+ vp.push_back(getPointerLB(std::string())); // FIXME: Diagnose this.
+ vp.push_back(getPointerLB(*getPointerLB(std::string()))); // FIXME: Diagnose
this.
+ vp.push_back(getPointerLB(local));
+ vp.push_back(getPointerNoLB(std::string()));
+
+ std::optional<std::string_view> optional;
+ vsv.push_back(optional.value());
+ vsv.push_back(getOptionalS().value()); // expected-warning {{object captured
by 'vsv'}}
+ vsv.push_back(getOptionalSV().value());
+ vsv.push_back(getOptionalMySV().value());
+ // FIXME: We should not diagnose the following case.
+ vsv.push_back(getOptionalMySVNotP().value()); // expected-warning {{object
captured by 'vsv'}}
+ vsv.push_back(getMySV());
+ vsv.push_back(getMySVNotP());
+ vsv.push_back(my_string_view{});
+ vsv.push_back(my_string_view_not_pointer{});
+}
+
+template<class T>
+struct MySet {
+void insert(T&& t [[clang::lifetime_capture_by(this)]]);
+void insert(const T& t [[clang::lifetime_capture_by(this)]]);
+};
+
+void user_defined_containers() {
+ // FIXME: We want this to diagnose 'set_of_sv' but not 'set_of_int' case.
+ // Currently, we cannot selectively trigger for pointer-like types and not
for other value-types.
+ MySet<int> set_of_int;
+ set_of_int.insert(1); // expected-warning {{object captured by 'set_of_int'
will be destroyed}}
+ MySet<std::string_view> set_of_sv;
+ set_of_sv.insert(std::string()); // expected-warning {{object captured by
'set_of_sv' will be destroyed}}
+}
+} // namespace lifetime_capture_by
+
+// Test for templated code.
+// 2 nested function calls foo(sv, bar(sv, setsv));
\ No newline at end of file
diff --git a/clang/test/SemaCXX/attr-lifetime-capture-by.cpp
b/clang/test/SemaCXX/attr-lifetime-capture-by.cpp
new file mode 100644
index 00000000000000..192ec9bec640a5
--- /dev/null
+++ b/clang/test/SemaCXX/attr-lifetime-capture-by.cpp
@@ -0,0 +1,40 @@
+// RUN: %clang_cc1 -std=c++23 -verify %s
+
+struct S {
+ const int *x;
+ void captureInt(const int&x [[clang::lifetime_capture_by(this)]]) { this->x
= &x; }
+};
+
+///////////////////////////
+// Test for valid usages.
+///////////////////////////
+[[clang::lifetime_capture_by(unknown)]] // expected-error
{{'lifetime_capture_by' attribute only applies to parameters and implicit
object parameters}}
+void nonMember(
+ const int &x1 [[clang::lifetime_capture_by(s, t)]],
+ S &s,
+ S &t,
+ const int &x2 [[clang::lifetime_capture_by(12345 + 12)]], //
expected-error {{'lifetime_capture_by' attribute argument 12345 + 12 is not a
known function parameter. Must be a function parameter of one of 'this',
'global' or 'unknown'}}
+ const int &x3 [[clang::lifetime_capture_by(abcdefgh)]], //
expected-error {{'lifetime_capture_by' attribute argument 'abcdefgh' is not a
known function parameter. Must be a function parameter of one of 'this',
'global' or 'unknown'}}
+ const int &x4 [[clang::lifetime_capture_by("abcdefgh")]], //
expected-error {{'lifetime_capture_by' attribute argument "abcdefgh" is not a
known function parameter. Must be a function parameter of one of 'this',
'global' or 'unknown'}}
+ const int &x5 [[clang::lifetime_capture_by(this)]], // expected-error
{{'lifetime_capture_by' argument references unavailable implicit 'this'}}
+ const int &x6 [[clang::lifetime_capture_by()]], // expected-error
{{'lifetime_capture_by' attribute specifies no capturing entity}}
+ const int& x7 [[clang::lifetime_capture_by(u,
+ x7)]], // expected-error
{{'lifetime_capture_by' argument references itself}}
+ const S& u
+ )
+{
+ s.captureInt(x1);
+}
+
+struct T {
+ void member(
+ const int &x [[clang::lifetime_capture_by(s)]],
+ S &s,
+ S &t,
+ const int &y [[clang::lifetime_capture_by(s)]],
+ const int &z [[clang::lifetime_capture_by(this, x, y)]],
+ const int &u [[clang::lifetime_capture_by(global, x, s)]])
+ {
+ s.captureInt(x);
+ }
+};
diff --git a/clang/test/SemaCXX/attr-lifetimebound.cpp
b/clang/test/SemaCXX/attr-lifetimebound.cpp
index 804d61fb62ca40..f81887a6933fda 100644
--- a/clang/test/SemaCXX/attr-lifetimebound.cpp
+++ b/clang/test/SemaCXX/attr-lifetimebound.cpp
@@ -93,7 +93,7 @@ namespace std {
char &operator[](size_t) const [[clang::lifetimebound]];
};
using string = basic_string<char>;
- string operator""s(const char *, size_t); // expected-warning {{user-defined
literal suffixes not starting with '_' are reserved}}
+ string operator""s(const char *, size_t); // expected-warning {{}}
template<typename T>
struct basic_string_view {
@@ -102,7 +102,7 @@ namespace std {
basic_string_view(const string &s [[clang::lifetimebound]]);
};
using string_view = basic_string_view<char>;
- string_view operator""sv(const char *, size_t); // expected-warning
{{user-defined literal suffixes not starting with '_' are reserved}}
+ string_view operator""sv(const char *, size_t); // expected-warning {{}}
struct vector {
int *data();
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