[clang] Reapply "[Clang][CWG1815] Support lifetime extension of temporary created by aggregate initialization using a default member initializer" (PR #108039)
via cfe-commits
cfe-commits at lists.llvm.org
Tue Sep 10 07:56:35 PDT 2024
https://github.com/yronglin created https://github.com/llvm/llvm-project/pull/108039
The PR reapply https://github.com/llvm/llvm-project/pull/97308.
Implement [CWG1815](https://wg21.link/CWG1815): Support lifetime extension of temporary created by aggregate initialization using a default member initializer.
Fix crash that introduced in https://github.com/llvm/llvm-project/pull/97308. In `InitListChecker::FillInEmptyInitForField`, when we enter rebuild-default-init context, we copy all the contents of the parent context to the current context, which will cause the `MaybeODRUseExprs` to be lost. But we don't need to copy the entire context, only the `DelayedDefaultInitializationContext` was required, which is used to build `SourceLocExpr`, etc.
>From a74835579629073b4542cad0d17d5f4c7f501d52 Mon Sep 17 00:00:00 2001
From: yronglin <yronglin777 at gmail.com>
Date: Tue, 10 Sep 2024 22:27:23 +0800
Subject: [PATCH 1/2] Reapply "[Clang][CWG1815] Support lifetime extension of
temporary created by aggregate initialization using a default member
initializer"
Signed-off-by: yronglin <yronglin777 at gmail.com>
---
clang/docs/ReleaseNotes.rst | 3 +
.../clang/Basic/DiagnosticSemaKinds.td | 7 --
clang/include/clang/Sema/Sema.h | 23 ++---
clang/lib/Parse/ParseDecl.cpp | 3 +-
clang/lib/Sema/CheckExprLifetime.cpp | 18 +---
clang/lib/Sema/SemaExpr.cpp | 36 +++++--
clang/lib/Sema/SemaExprCXX.cpp | 3 -
clang/lib/Sema/SemaInit.cpp | 22 +++--
.../lib/Sema/SemaTemplateInstantiateDecl.cpp | 5 +-
clang/lib/Sema/TreeTransform.h | 20 ++--
clang/test/AST/ast-dump-default-init-json.cpp | 6 +-
clang/test/AST/ast-dump-default-init.cpp | 2 +-
.../Analysis/lifetime-extended-regions.cpp | 9 +-
clang/test/CXX/drs/cwg16xx.cpp | 23 ++++-
clang/test/CXX/drs/cwg18xx.cpp | 19 +++-
clang/test/CXX/special/class.temporary/p6.cpp | 34 +++++++
clang/test/SemaCXX/constexpr-default-arg.cpp | 4 +-
.../cxx11-default-member-initializers.cpp | 93 +++++++++++++++++++
clang/test/SemaCXX/eval-crashes.cpp | 6 +-
clang/www/cxx_dr_status.html | 2 +-
20 files changed, 251 insertions(+), 87 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 250821a9f9c45c..07f3544e2324e3 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -108,6 +108,9 @@ C++ Language Changes
- Allow single element access of GCC vector/ext_vector_type object to be
constant expression. Supports the `V.xyzw` syntax and other tidbits
as seen in OpenCL. Selecting multiple elements is left as a future work.
+- Implement `CWG1815 <https://wg21.link/CWG1815>`_. Support lifetime extension
+ of temporary created by aggregate initialization using a default member
+ initializer.
- Accept C++26 user-defined ``static_assert`` messages in C++11 as an extension.
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 58819a64813fce..4609d2ec2b7209 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10159,13 +10159,6 @@ def warn_dangling_pointer_assignment : Warning<
"will be destroyed at the end of the full-expression">,
InGroup<DanglingAssignment>;
-def warn_unsupported_lifetime_extension : Warning<
- "lifetime extension of "
- "%select{temporary|backing array of initializer list}0 created "
- "by aggregate initialization using a default member initializer "
- "is not yet supported; lifetime of %select{temporary|backing array}0 "
- "will end at the end of the full-expression">, InGroup<Dangling>;
-
// 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.
// Array comparisons have similar warnings
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 68c782a15c6f1b..ac4c11964b126f 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -6403,6 +6403,9 @@ class Sema final : public SemaBase {
/// example, in a for-range initializer).
bool InLifetimeExtendingContext = false;
+ /// Whether we should rebuild CXXDefaultArgExpr and CXXDefaultInitExpr.
+ bool RebuildDefaultArgOrDefaultInit = false;
+
// When evaluating immediate functions in the initializer of a default
// argument or default member initializer, this is the declaration whose
// default initializer is being evaluated and the location of the call
@@ -7810,9 +7813,11 @@ class Sema final : public SemaBase {
}
bool isInLifetimeExtendingContext() const {
- assert(!ExprEvalContexts.empty() &&
- "Must be in an expression evaluation context");
- return ExprEvalContexts.back().InLifetimeExtendingContext;
+ return currentEvaluationContext().InLifetimeExtendingContext;
+ }
+
+ bool needRebuildDefaultArgOrInit() const {
+ return currentEvaluationContext().RebuildDefaultArgOrDefaultInit;
}
bool isCheckingDefaultArgumentOrInitializer() const {
@@ -7854,18 +7859,6 @@ class Sema final : public SemaBase {
return Res;
}
- /// keepInLifetimeExtendingContext - Pull down InLifetimeExtendingContext
- /// flag from previous context.
- void keepInLifetimeExtendingContext() {
- if (ExprEvalContexts.size() > 2 &&
- parentEvaluationContext().InLifetimeExtendingContext) {
- auto &LastRecord = ExprEvalContexts.back();
- auto &PrevRecord = parentEvaluationContext();
- LastRecord.InLifetimeExtendingContext =
- PrevRecord.InLifetimeExtendingContext;
- }
- }
-
DefaultedComparisonKind getDefaultedComparisonKind(const FunctionDecl *FD) {
return getDefaultedFunctionKind(FD).asComparison();
}
diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index 61a1ca3da6bca0..1f56884be392d6 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -2509,8 +2509,9 @@ Parser::DeclGroupPtrTy Parser::ParseDeclGroup(ParsingDeclSpec &DS,
// P2718R0 - Lifetime extension in range-based for loops.
if (getLangOpts().CPlusPlus23) {
- auto &LastRecord = Actions.ExprEvalContexts.back();
+ auto &LastRecord = Actions.currentEvaluationContext();
LastRecord.InLifetimeExtendingContext = true;
+ LastRecord.RebuildDefaultArgOrDefaultInit = true;
}
if (getLangOpts().OpenMP)
diff --git a/clang/lib/Sema/CheckExprLifetime.cpp b/clang/lib/Sema/CheckExprLifetime.cpp
index f1507ebb9a5068..f62e18543851c1 100644
--- a/clang/lib/Sema/CheckExprLifetime.cpp
+++ b/clang/lib/Sema/CheckExprLifetime.cpp
@@ -871,11 +871,6 @@ static void visitLocalsRetainedByInitializer(IndirectLocalPath &Path,
enum PathLifetimeKind {
/// Lifetime-extend along this path.
Extend,
- /// We should lifetime-extend, but we don't because (due to technical
- /// limitations) we can't. This happens for default member initializers,
- /// which we don't clone for every use, so we don't have a unique
- /// MaterializeTemporaryExpr to update.
- ShouldExtend,
/// Do not lifetime extend along this path.
NoExtend
};
@@ -887,7 +882,7 @@ shouldLifetimeExtendThroughPath(const IndirectLocalPath &Path) {
PathLifetimeKind Kind = PathLifetimeKind::Extend;
for (auto Elem : Path) {
if (Elem.Kind == IndirectLocalPathEntry::DefaultInit)
- Kind = PathLifetimeKind::ShouldExtend;
+ return PathLifetimeKind::Extend;
else if (Elem.Kind != IndirectLocalPathEntry::LambdaCaptureInit)
return PathLifetimeKind::NoExtend;
}
@@ -1034,17 +1029,6 @@ static void checkExprLifetimeImpl(Sema &SemaRef,
// Also visit the temporaries lifetime-extended by this initializer.
return true;
- case PathLifetimeKind::ShouldExtend:
- // We're supposed to lifetime-extend the temporary along this path (per
- // the resolution of DR1815), but we don't support that yet.
- //
- // FIXME: Properly handle this situation. Perhaps the easiest approach
- // would be to clone the initializer expression on each use that would
- // lifetime extend its temporaries.
- SemaRef.Diag(DiagLoc, diag::warn_unsupported_lifetime_extension)
- << RK << DiagRange;
- break;
-
case PathLifetimeKind::NoExtend:
// If the path goes through the initialization of a variable or field,
// it can't possibly reach a temporary created in this full-expression.
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 32dac4440fb82a..30e5fe4543bcaa 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -5429,6 +5429,8 @@ struct EnsureImmediateInvocationInDefaultArgs
EnsureImmediateInvocationInDefaultArgs(Sema &SemaRef)
: TreeTransform(SemaRef) {}
+ bool AlwaysRebuild() { return true; }
+
// Lambda can only have immediate invocations in the default
// args of their parameters, which is transformed upon calling the closure.
// The body is not a subexpression, so we have nothing to do.
@@ -5470,7 +5472,7 @@ ExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc,
assert(Param->hasDefaultArg() && "can't build nonexistent default arg");
bool NestedDefaultChecking = isCheckingDefaultArgumentOrInitializer();
- bool InLifetimeExtendingContext = isInLifetimeExtendingContext();
+ bool NeedRebuild = needRebuildDefaultArgOrInit();
std::optional<ExpressionEvaluationContextRecord::InitializationContext>
InitializationContext =
OutermostDeclarationWithDelayedImmediateInvocations();
@@ -5506,13 +5508,15 @@ ExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc,
// Rewrite the call argument that was created from the corresponding
// parameter's default argument.
- if (V.HasImmediateCalls || InLifetimeExtendingContext) {
+ if (V.HasImmediateCalls ||
+ (NeedRebuild && isa_and_present<ExprWithCleanups>(Param->getInit()))) {
if (V.HasImmediateCalls)
ExprEvalContexts.back().DelayedDefaultInitializationContext = {
CallLoc, Param, CurContext};
// Pass down lifetime extending flag, and collect temporaries in
// CreateMaterializeTemporaryExpr when we rewrite the call argument.
- keepInLifetimeExtendingContext();
+ currentEvaluationContext().InLifetimeExtendingContext =
+ parentEvaluationContext().InLifetimeExtendingContext;
EnsureImmediateInvocationInDefaultArgs Immediate(*this);
ExprResult Res;
runWithSufficientStackSpace(CallLoc, [&] {
@@ -5558,7 +5562,7 @@ ExprResult Sema::BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field) {
Expr *Init = nullptr;
bool NestedDefaultChecking = isCheckingDefaultArgumentOrInitializer();
-
+ bool NeedRebuild = needRebuildDefaultArgOrInit();
EnterExpressionEvaluationContext EvalContext(
*this, ExpressionEvaluationContext::PotentiallyEvaluated, Field);
@@ -5593,12 +5597,27 @@ ExprResult Sema::BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field) {
ImmediateCallVisitor V(getASTContext());
if (!NestedDefaultChecking)
V.TraverseDecl(Field);
- if (V.HasImmediateCalls) {
+
+ // CWG1815
+ // Support lifetime extension of temporary created by aggregate
+ // initialization using a default member initializer. We should rebuild
+ // the initializer in a lifetime extension context if the initializer
+ // expression is an ExprWithCleanups. Then make sure the normal lifetime
+ // extension code recurses into the default initializer and does lifetime
+ // extension when warranted.
+ bool ContainsAnyTemporaries =
+ isa_and_present<ExprWithCleanups>(Field->getInClassInitializer());
+ if (Field->getInClassInitializer() &&
+ !Field->getInClassInitializer()->containsErrors() &&
+ (V.HasImmediateCalls || (NeedRebuild && ContainsAnyTemporaries))) {
ExprEvalContexts.back().DelayedDefaultInitializationContext = {Loc, Field,
CurContext};
ExprEvalContexts.back().IsCurrentlyCheckingDefaultArgumentOrInitializer =
NestedDefaultChecking;
-
+ // Pass down lifetime extending flag, and collect temporaries in
+ // CreateMaterializeTemporaryExpr when we rewrite the call argument.
+ currentEvaluationContext().InLifetimeExtendingContext =
+ parentEvaluationContext().InLifetimeExtendingContext;
EnsureImmediateInvocationInDefaultArgs Immediate(*this);
ExprResult Res;
runWithSufficientStackSpace(Loc, [&] {
@@ -17675,11 +17694,10 @@ void Sema::PopExpressionEvaluationContext() {
// Append the collected materialized temporaries into previous context before
// exit if the previous also is a lifetime extending context.
- auto &PrevRecord = parentEvaluationContext();
if (getLangOpts().CPlusPlus23 && Rec.InLifetimeExtendingContext &&
- PrevRecord.InLifetimeExtendingContext &&
+ parentEvaluationContext().InLifetimeExtendingContext &&
!Rec.ForRangeLifetimeExtendTemps.empty()) {
- PrevRecord.ForRangeLifetimeExtendTemps.append(
+ parentEvaluationContext().ForRangeLifetimeExtendTemps.append(
Rec.ForRangeLifetimeExtendTemps);
}
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 14feafd1e6b17f..e086c601107041 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -1540,9 +1540,6 @@ Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo,
bool ListInitialization) {
QualType Ty = TInfo->getType();
SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc();
-
- assert((!ListInitialization || Exprs.size() == 1) &&
- "List initialization must have exactly one expression.");
SourceRange FullRange = SourceRange(TyBeginLoc, RParenOrBraceLoc);
InitializedEntity Entity =
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 7dc17187524621..de2686e447892e 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -750,8 +750,20 @@ void InitListChecker::FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
if (Field->hasInClassInitializer()) {
if (VerifyOnly)
return;
-
- ExprResult DIE = SemaRef.BuildCXXDefaultInitExpr(Loc, Field);
+ ExprResult DIE;
+ {
+ // Enter a default initializer rebuild context, then we can support
+ // lifetime extension of temporary created by aggregate initialization
+ // using a default member initializer.
+ // CWG1815 (https://wg21.link/CWG1815).
+ EnterExpressionEvaluationContext RebuildDefaultInit(
+ SemaRef, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
+ // Just copy previous record, make sure we haven't forget anything.
+ SemaRef.currentEvaluationContext() = SemaRef.parentEvaluationContext();
+ SemaRef.currentEvaluationContext().RebuildDefaultArgOrDefaultInit =
+ true;
+ DIE = SemaRef.BuildCXXDefaultInitExpr(Loc, Field);
+ }
if (DIE.isInvalid()) {
hadError = true;
return;
@@ -7521,10 +7533,8 @@ Sema::CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary,
// are done in both CreateMaterializeTemporaryExpr and MaybeBindToTemporary,
// but there may be a chance to merge them.
Cleanup.setExprNeedsCleanups(false);
- if (isInLifetimeExtendingContext()) {
- auto &Record = ExprEvalContexts.back();
- Record.ForRangeLifetimeExtendTemps.push_back(MTE);
- }
+ if (isInLifetimeExtendingContext())
+ currentEvaluationContext().ForRangeLifetimeExtendTemps.push_back(MTE);
return MTE;
}
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 6df412cbb09c83..bb311e38409280 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -5481,7 +5481,10 @@ void Sema::InstantiateVariableInitializer(
EnterExpressionEvaluationContext Evaluated(
*this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated, Var);
- keepInLifetimeExtendingContext();
+ currentEvaluationContext().InLifetimeExtendingContext =
+ parentEvaluationContext().InLifetimeExtendingContext;
+ currentEvaluationContext().RebuildDefaultArgOrDefaultInit =
+ parentEvaluationContext().RebuildDefaultArgOrDefaultInit;
// Instantiate the initializer.
ExprResult Init;
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 0daf620b4123e4..4bbc024587915c 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -4254,7 +4254,10 @@ ExprResult TreeTransform<Derived>::TransformInitializer(Expr *Init,
getSema(), EnterExpressionEvaluationContext::InitList,
Construct->isListInitialization());
- getSema().keepInLifetimeExtendingContext();
+ getSema().currentEvaluationContext().InLifetimeExtendingContext =
+ getSema().parentEvaluationContext().InLifetimeExtendingContext;
+ getSema().currentEvaluationContext().RebuildDefaultArgOrDefaultInit =
+ getSema().parentEvaluationContext().RebuildDefaultArgOrDefaultInit;
SmallVector<Expr*, 8> NewArgs;
bool ArgChanged = false;
if (getDerived().TransformExprs(Construct->getArgs(), Construct->getNumArgs(),
@@ -8924,8 +8927,9 @@ TreeTransform<Derived>::TransformCXXForRangeStmt(CXXForRangeStmt *S) {
// P2718R0 - Lifetime extension in range-based for loops.
if (getSema().getLangOpts().CPlusPlus23) {
- auto &LastRecord = getSema().ExprEvalContexts.back();
+ auto &LastRecord = getSema().currentEvaluationContext();
LastRecord.InLifetimeExtendingContext = true;
+ LastRecord.RebuildDefaultArgOrDefaultInit = true;
}
StmtResult Init =
S->getInit() ? getDerived().TransformStmt(S->getInit()) : StmtResult();
@@ -14443,6 +14447,13 @@ TreeTransform<Derived>::TransformCXXTemporaryObjectExpr(
if (TransformExprs(E->getArgs(), E->getNumArgs(), true, Args,
&ArgumentChanged))
return ExprError();
+
+ if (E->isListInitialization() && !E->isStdInitListInitialization()) {
+ ExprResult Res = RebuildInitList(E->getBeginLoc(), Args, E->getEndLoc());
+ if (Res.isInvalid())
+ return ExprError();
+ Args = {Res.get()};
+ }
}
if (!getDerived().AlwaysRebuild() &&
@@ -14454,12 +14465,9 @@ TreeTransform<Derived>::TransformCXXTemporaryObjectExpr(
return SemaRef.MaybeBindToTemporary(E);
}
- // FIXME: We should just pass E->isListInitialization(), but we're not
- // prepared to handle list-initialization without a child InitListExpr.
SourceLocation LParenLoc = T->getTypeLoc().getEndLoc();
return getDerived().RebuildCXXTemporaryObjectExpr(
- T, LParenLoc, Args, E->getEndLoc(),
- /*ListInitialization=*/LParenLoc.isInvalid());
+ T, LParenLoc, Args, E->getEndLoc(), E->isListInitialization());
}
template<typename Derived>
diff --git a/clang/test/AST/ast-dump-default-init-json.cpp b/clang/test/AST/ast-dump-default-init-json.cpp
index 1058b4e3ea4d93..f4949a9c9eedf4 100644
--- a/clang/test/AST/ast-dump-default-init-json.cpp
+++ b/clang/test/AST/ast-dump-default-init-json.cpp
@@ -789,10 +789,10 @@ void test() {
// CHECK-NEXT: "valueCategory": "lvalue",
// CHECK-NEXT: "extendingDecl": {
// CHECK-NEXT: "id": "0x{{.*}}",
-// CHECK-NEXT: "kind": "FieldDecl",
-// CHECK-NEXT: "name": "a",
+// CHECK-NEXT: "kind": "VarDecl",
+// CHECK-NEXT: "name": "b",
// CHECK-NEXT: "type": {
-// CHECK-NEXT: "qualType": "const A &"
+// CHECK-NEXT: "qualType": "B"
// CHECK-NEXT: }
// CHECK-NEXT: },
// CHECK-NEXT: "storageDuration": "automatic",
diff --git a/clang/test/AST/ast-dump-default-init.cpp b/clang/test/AST/ast-dump-default-init.cpp
index 15b29f04bf21bf..26864fbf15424d 100644
--- a/clang/test/AST/ast-dump-default-init.cpp
+++ b/clang/test/AST/ast-dump-default-init.cpp
@@ -13,7 +13,7 @@ void test() {
}
// CHECK: -CXXDefaultInitExpr 0x{{[^ ]*}} <{{.*}}> 'const A' lvalue has rewritten init
// CHECK-NEXT: `-ExprWithCleanups 0x{{[^ ]*}} <{{.*}}> 'const A' lvalue
-// CHECK-NEXT: `-MaterializeTemporaryExpr 0x{{[^ ]*}} <{{.*}}> 'const A' lvalue extended by Field 0x{{[^ ]*}} 'a' 'const A &'
+// CHECK-NEXT: `-MaterializeTemporaryExpr 0x{{[^ ]*}} <{{.*}}> 'const A' lvalue extended by Var 0x{{[^ ]*}} 'b' 'B'
// CHECK-NEXT: `-ImplicitCastExpr 0x{{[^ ]*}} <{{.*}}> 'const A' <NoOp>
// CHECK-NEXT: `-CXXFunctionalCastExpr 0x{{[^ ]*}} <{{.*}}> 'A' functional cast to A <NoOp>
// CHECK-NEXT: `-InitListExpr 0x{{[^ ]*}} <{{.*}}> 'A'
diff --git a/clang/test/Analysis/lifetime-extended-regions.cpp b/clang/test/Analysis/lifetime-extended-regions.cpp
index 4e98bd4b0403eb..4458ad294af7cb 100644
--- a/clang/test/Analysis/lifetime-extended-regions.cpp
+++ b/clang/test/Analysis/lifetime-extended-regions.cpp
@@ -120,10 +120,11 @@ void aggregateWithReferences() {
clang_analyzer_dump(viaReference); // expected-warning-re {{&lifetime_extended_object{RefAggregate, viaReference, S{{[0-9]+}}} }}
clang_analyzer_dump(viaReference.rx); // expected-warning-re {{&lifetime_extended_object{int, viaReference, S{{[0-9]+}}} }}
clang_analyzer_dump(viaReference.ry); // expected-warning-re {{&lifetime_extended_object{Composite, viaReference, S{{[0-9]+}}} }}
-
- // clang does not currently implement extending lifetime of object bound to reference members of aggregates,
- // that are created from default member initializer (see `warn_unsupported_lifetime_extension` from `-Wdangling`)
- RefAggregate defaultInitExtended{i}; // clang-bug does not extend `Composite`
+
+ // FIXME: clang currently support extending lifetime of object bound to reference members of aggregates,
+ // that are created from default member initializer. But CFG and ExprEngine need to be updated to address this change.
+ // The following expect warning: {{&lifetime_extended_object{Composite, defaultInitExtended, S{{[0-9]+}}} }}
+ RefAggregate defaultInitExtended{i};
clang_analyzer_dump(defaultInitExtended.ry); // expected-warning {{Unknown }}
}
diff --git a/clang/test/CXX/drs/cwg16xx.cpp b/clang/test/CXX/drs/cwg16xx.cpp
index cf6b45ceabf2cc..95e241f0d03e9b 100644
--- a/clang/test/CXX/drs/cwg16xx.cpp
+++ b/clang/test/CXX/drs/cwg16xx.cpp
@@ -449,6 +449,27 @@ namespace cwg1696 { // cwg1696: 7
// since-cxx14-note at -2 {{default member initializer declared here}}
};
A a{a, a};
+
+ struct A1 {
+ A1() : v(42) {}
+ // since-cxx14-error at -1 {{reference member 'v' binds to a temporary object whose lifetime would be shorter than the lifetime of the constructed object}}
+ // since-cxx14-note@#cwg1696-A1 {{reference member declared here}}
+ const int &v; // #cwg1696-A1
+ };
+
+ struct A2 {
+ A2() = default;
+ // since-cxx14-error at -1 {{reference member 'v' binds to a temporary object whose lifetime would be shorter than the lifetime of the constructed object}}
+ // since-cxx14-note-re@#cwg1696-A2-b {{in defaulted default constructor for {{.*}} first required here}}
+ // since-cxx14-note@#cwg1696-A2-a {{initializing field 'v' with default member initializer}}
+ A2(int v) : v(v) {}
+ // since-cxx14-warning at -1 {{binding reference member 'v' to stack allocated parameter 'v'}}
+ // since-cxx14-note@#cwg1696-A2-a {{reference member declared here}}
+ const int &v = 42; // #cwg1696-A2-a
+ };
+ A2 a1; // #cwg1696-A2-b
+
+ A2 a2(1); // OK, unfortunately
#endif
}
@@ -483,8 +504,6 @@ namespace cwg1696 { // cwg1696: 7
const A &a = A(); // #cwg1696-D1-a
};
D1 d1 = {}; // #cwg1696-d1
- // since-cxx14-warning at -1 {{lifetime extension of temporary created by aggregate initialization using a default member initializer is not yet supported; lifetime of temporary will end at the end of the full-expression}}
- // since-cxx14-note@#cwg1696-D1-a {{initializing field 'a' with default member initializer}}
struct D2 {
const A &a = A(); // #cwg1696-D2-a
diff --git a/clang/test/CXX/drs/cwg18xx.cpp b/clang/test/CXX/drs/cwg18xx.cpp
index 61b7faa96a9fbb..7f0fb8cf589d48 100644
--- a/clang/test/CXX/drs/cwg18xx.cpp
+++ b/clang/test/CXX/drs/cwg18xx.cpp
@@ -206,19 +206,28 @@ namespace cwg1814 { // cwg1814: yes
#endif
}
-namespace cwg1815 { // cwg1815: no
+namespace cwg1815 { // cwg1815: 20
#if __cplusplus >= 201402L
- // FIXME: needs codegen test
- struct A { int &&r = 0; }; // #cwg1815-A
+ struct A { int &&r = 0; };
A a = {};
- // since-cxx14-warning at -1 {{lifetime extension of temporary created by aggregate initialization using a default member initializer is not yet supported; lifetime of temporary will end at the end of the full-expression}} FIXME
- // since-cxx14-note@#cwg1815-A {{initializing field 'r' with default member initializer}}
struct B { int &&r = 0; }; // #cwg1815-B
// since-cxx14-error at -1 {{reference member 'r' binds to a temporary object whose lifetime would be shorter than the lifetime of the constructed object}}
// since-cxx14-note@#cwg1815-B {{initializing field 'r' with default member initializer}}
// since-cxx14-note@#cwg1815-b {{in implicit default constructor for 'cwg1815::B' first required here}}
B b; // #cwg1815-b
+
+#if __cplusplus >= 201703L
+ struct C { const int &r = 0; };
+ constexpr C c = {}; // OK, since cwg1815
+ static_assert(c.r == 0);
+
+ constexpr int f() {
+ A a = {}; // OK, since cwg1815
+ return a.r;
+ }
+ static_assert(f() == 0);
+#endif
#endif
}
diff --git a/clang/test/CXX/special/class.temporary/p6.cpp b/clang/test/CXX/special/class.temporary/p6.cpp
index 5554363cc69abb..a6d2adfd1fd2c5 100644
--- a/clang/test/CXX/special/class.temporary/p6.cpp
+++ b/clang/test/CXX/special/class.temporary/p6.cpp
@@ -269,6 +269,40 @@ void init_capture_init_list() {
// CHECK: }
}
+void check_dr1815() { // dr1815: yes
+#if __cplusplus >= 201402L
+
+ struct A {
+ int &&r = 0;
+ ~A() {}
+ };
+
+ struct B {
+ A &&a = A{};
+ ~B() {}
+ };
+ B a = {};
+
+ // CHECK: call {{.*}}block_scope_begin_function
+ extern void block_scope_begin_function();
+ extern void block_scope_end_function();
+ block_scope_begin_function();
+ {
+ // CHECK: call void @_ZZ12check_dr1815vEN1BD1Ev
+ // CHECK: call void @_ZZ12check_dr1815vEN1AD1Ev
+ B b = {};
+ }
+ // CHECK: call {{.*}}block_scope_end_function
+ block_scope_end_function();
+
+ // CHECK: call {{.*}}some_other_function
+ extern void some_other_function();
+ some_other_function();
+ // CHECK: call void @_ZZ12check_dr1815vEN1BD1Ev
+ // CHECK: call void @_ZZ12check_dr1815vEN1AD1Ev
+#endif
+}
+
namespace P2718R0 {
namespace basic {
template <typename E> using T2 = std::list<E>;
diff --git a/clang/test/SemaCXX/constexpr-default-arg.cpp b/clang/test/SemaCXX/constexpr-default-arg.cpp
index ec9b2927880bdf..901123bfb359ff 100644
--- a/clang/test/SemaCXX/constexpr-default-arg.cpp
+++ b/clang/test/SemaCXX/constexpr-default-arg.cpp
@@ -32,8 +32,8 @@ void test_default_arg2() {
}
// Check that multiple CXXDefaultInitExprs don't cause an assertion failure.
-struct A { int &&r = 0; }; // expected-note 2{{default member initializer}}
+struct A { int &&r = 0; };
struct B { A x, y; };
-B b = {}; // expected-warning 2{{lifetime extension of temporary created by aggregate initialization using a default member initializer is not yet supported}}
+B b = {}; // expected-no-diagnostics
}
diff --git a/clang/test/SemaCXX/cxx11-default-member-initializers.cpp b/clang/test/SemaCXX/cxx11-default-member-initializers.cpp
index dd8e9c6b7fc11f..b3f3eb508446b6 100644
--- a/clang/test/SemaCXX/cxx11-default-member-initializers.cpp
+++ b/clang/test/SemaCXX/cxx11-default-member-initializers.cpp
@@ -27,6 +27,99 @@ class MemInit {
C m = s;
};
+namespace std {
+typedef decltype(sizeof(int)) size_t;
+
+// libc++'s implementation
+template <class _E> class initializer_list {
+ const _E *__begin_;
+ size_t __size_;
+
+ initializer_list(const _E *__b, size_t __s) : __begin_(__b), __size_(__s) {}
+
+public:
+ typedef _E value_type;
+ typedef const _E &reference;
+ typedef const _E &const_reference;
+ typedef size_t size_type;
+
+ typedef const _E *iterator;
+ typedef const _E *const_iterator;
+
+ initializer_list() : __begin_(nullptr), __size_(0) {}
+
+ size_t size() const { return __size_; }
+ const _E *begin() const { return __begin_; }
+ const _E *end() const { return __begin_ + __size_; }
+};
+} // namespace std
+
+#if __cplusplus >= 201703L
+namespace test_rebuild {
+template <typename T, int> class C {
+public:
+ C(std::initializer_list<T>);
+};
+
+template <typename T> using Ptr = __remove_pointer(T) *;
+template <typename T> C(T) -> C<Ptr<T>, sizeof(T)>;
+
+class A {
+public:
+ template <typename T1, typename T2> T1 *some_func(T2 &&);
+};
+
+struct B : A {
+ // Test CXXDefaultInitExpr rebuild issue in
+ // https://github.com/llvm/llvm-project/pull/87933
+ int *ar = some_func<int>(C{some_func<int>(0)});
+ B() {}
+};
+
+int TestBody_got;
+template <int> class Vector {
+public:
+ Vector(std::initializer_list<int>);
+};
+template <typename... Ts> Vector(Ts...) -> Vector<sizeof...(Ts)>;
+class ProgramBuilder {
+public:
+ template <typename T, typename ARGS> int *create(ARGS);
+};
+
+struct TypeTest : ProgramBuilder {
+ int *str_f16 = create<int>(Vector{0});
+ TypeTest() {}
+};
+class TypeTest_Element_Test : TypeTest {
+ void TestBody();
+};
+void TypeTest_Element_Test::TestBody() {
+ int *expect = str_f16;
+ &TestBody_got != expect; // expected-warning {{inequality comparison result unused}}
+}
+} // namespace test_rebuild
+namespace test_rebuild2 {
+struct F {
+ int g;
+};
+struct H {};
+struct I {
+ I(const F &);
+ I(H);
+};
+struct L {
+ I i = I({.g = 0});
+};
+struct N : L {};
+
+void f() {
+ delete new L; // Ok
+ delete new N; // Ok
+}
+} // namespace test_rebuild2
+#endif // __cplusplus >= 201703L
+
#if __cplusplus >= 202002L
// This test ensures cleanup expressions are correctly produced
// in the presence of default member initializers.
diff --git a/clang/test/SemaCXX/eval-crashes.cpp b/clang/test/SemaCXX/eval-crashes.cpp
index 0865dafe4bf92a..21e05f19be0caa 100644
--- a/clang/test/SemaCXX/eval-crashes.cpp
+++ b/clang/test/SemaCXX/eval-crashes.cpp
@@ -25,11 +25,9 @@ namespace pr33140_0b {
}
namespace pr33140_2 {
- // FIXME: The declaration of 'b' below should lifetime-extend two int
- // temporaries.
- struct A { int &&r = 0; }; // expected-note 2{{initializing field 'r' with default member initializer}}
+ struct A { int &&r = 0; };
struct B { A x, y; };
- B b = {}; // expected-warning 2{{lifetime extension of temporary created by aggregate initialization using a default member initializer is not yet supported}}
+ B b = {};
}
namespace pr33140_3 {
diff --git a/clang/www/cxx_dr_status.html b/clang/www/cxx_dr_status.html
index b638f0ff30bcce..f036fc5add2413 100755
--- a/clang/www/cxx_dr_status.html
+++ b/clang/www/cxx_dr_status.html
@@ -10717,7 +10717,7 @@ <h2 id="cxxdr">C++ defect report implementation status</h2>
<td><a href="https://cplusplus.github.io/CWG/issues/1815.html">1815</a></td>
<td>CD4</td>
<td>Lifetime extension in aggregate initialization</td>
- <td class="none" align="center">No</td>
+ <td class="unreleased" align="center">Clang 20</td>
</tr>
<tr id="1816">
<td><a href="https://cplusplus.github.io/CWG/issues/1816.html">1816</a></td>
>From 0f690b49fb61fe2925e45c595691e6b11e894565 Mon Sep 17 00:00:00 2001
From: yronglin <yronglin777 at gmail.com>
Date: Tue, 10 Sep 2024 22:39:36 +0800
Subject: [PATCH 2/2] Do not copy parent context, only copy
DelayedDefaultInitializationContext
Signed-off-by: yronglin <yronglin777 at gmail.com>
---
clang/lib/Sema/SemaInit.cpp | 5 +++--
clang/test/SemaCXX/PR97308.cpp | 21 +++++++++++++++++++
.../cxx11-default-member-initializers.cpp | 8 +++++--
3 files changed, 30 insertions(+), 4 deletions(-)
create mode 100644 clang/test/SemaCXX/PR97308.cpp
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index de2686e447892e..d21b8cb8c04e63 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -758,10 +758,11 @@ void InitListChecker::FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
// CWG1815 (https://wg21.link/CWG1815).
EnterExpressionEvaluationContext RebuildDefaultInit(
SemaRef, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
- // Just copy previous record, make sure we haven't forget anything.
- SemaRef.currentEvaluationContext() = SemaRef.parentEvaluationContext();
SemaRef.currentEvaluationContext().RebuildDefaultArgOrDefaultInit =
true;
+ SemaRef.currentEvaluationContext().DelayedDefaultInitializationContext =
+ SemaRef.parentEvaluationContext()
+ .DelayedDefaultInitializationContext;
DIE = SemaRef.BuildCXXDefaultInitExpr(Loc, Field);
}
if (DIE.isInvalid()) {
diff --git a/clang/test/SemaCXX/PR97308.cpp b/clang/test/SemaCXX/PR97308.cpp
new file mode 100644
index 00000000000000..7f550bc15d741c
--- /dev/null
+++ b/clang/test/SemaCXX/PR97308.cpp
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -o - -emit-llvm -triple x86_64-linux-gnu %s
+
+// Check there are no crash issue CodeGen action.
+// https://github.com/llvm/llvm-project/pull/97308
+struct a {
+} constexpr b;
+class c {
+public:
+ c(a);
+};
+class B {
+public:
+ using d = int;
+ struct e {
+ enum { f } g;
+ int h;
+ c i;
+ d j{};
+ };
+};
+B::e k{B::e::f, int(), b};
diff --git a/clang/test/SemaCXX/cxx11-default-member-initializers.cpp b/clang/test/SemaCXX/cxx11-default-member-initializers.cpp
index b3f3eb508446b6..5e26c3a3b82cd5 100644
--- a/clang/test/SemaCXX/cxx11-default-member-initializers.cpp
+++ b/clang/test/SemaCXX/cxx11-default-member-initializers.cpp
@@ -55,6 +55,9 @@ template <class _E> class initializer_list {
} // namespace std
#if __cplusplus >= 201703L
+
+// Test CXXDefaultInitExpr rebuild issue in
+// https://github.com/llvm/llvm-project/pull/87933
namespace test_rebuild {
template <typename T, int> class C {
public:
@@ -70,8 +73,6 @@ class A {
};
struct B : A {
- // Test CXXDefaultInitExpr rebuild issue in
- // https://github.com/llvm/llvm-project/pull/87933
int *ar = some_func<int>(C{some_func<int>(0)});
B() {}
};
@@ -99,6 +100,9 @@ void TypeTest_Element_Test::TestBody() {
&TestBody_got != expect; // expected-warning {{inequality comparison result unused}}
}
} // namespace test_rebuild
+
+// Test CXXDefaultInitExpr rebuild issue in
+// https://github.com/llvm/llvm-project/pull/92527
namespace test_rebuild2 {
struct F {
int g;
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