[clang] 5c8ba28 - [C11] Implement WG14 N1285 (temporary lifetimes) (#133472)
via cfe-commits
cfe-commits at lists.llvm.org
Thu Apr 10 05:12:17 PDT 2025
Author: Aaron Ballman
Date: 2025-04-10T08:12:14-04:00
New Revision: 5c8ba28c751bf0e7cb5c3ac9d223acba4cefc739
URL: https://github.com/llvm/llvm-project/commit/5c8ba28c751bf0e7cb5c3ac9d223acba4cefc739
DIFF: https://github.com/llvm/llvm-project/commit/5c8ba28c751bf0e7cb5c3ac9d223acba4cefc739.diff
LOG: [C11] Implement WG14 N1285 (temporary lifetimes) (#133472)
This feature largely models the same behavior as in C++11. It is
technically a breaking change between C99 and C11, so the paper is not
being backported to older language modes.
One difference between C++ and C is that things which are rvalues in C
are often lvalues in C++ (such as the result of a ternary operator or a
comma operator).
Fixes #96486
Added:
clang/test/C/C11/n1285_1.c
Modified:
clang/docs/ReleaseNotes.rst
clang/lib/CodeGen/CGDecl.cpp
clang/lib/CodeGen/CGExpr.cpp
clang/lib/CodeGen/CodeGenFunction.h
clang/lib/Sema/SemaInit.cpp
clang/test/C/C11/n1285.c
clang/test/CodeGen/xcore-abi.c
clang/test/CodeGenObjC/property-array-type.m
clang/www/c_status.html
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index cd16641c25ed8..c6dbd056a663c 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -162,6 +162,18 @@ C23 Feature Support
- Fixed a bug where you could not cast a null pointer constant to type
``nullptr_t``. Fixes #GH133644.
+C11 Feature Support
+^^^^^^^^^^^^^^^^^^^
+- Implemented `WG14 N1285 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1285.htm>`_
+ which introduces the notion of objects with a temporary lifetime. When an
+ expression resulting in an rvalue with structure or union type and that type
+ contains a member of array type, the expression result is an automatic storage
+ duration object with temporary lifetime which begins when the expression is
+ evaluated and ends at the evaluation of the containing full expression. This
+ functionality is also implemented for earlier C language modes because the
+ C99 semantics will never be implemented (it would require dynamic allocations
+ of memory which leaks, which users would not appreciate).
+
Non-comprehensive list of changes in this release
-------------------------------------------------
diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 0af170a36f372..db8dbf86eca4f 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -2265,11 +2265,18 @@ void CodeGenFunction::pushDestroy(QualType::DestructionKind dtorKind,
cleanupKind & EHCleanup);
}
+void CodeGenFunction::pushLifetimeExtendedDestroy(
+ QualType::DestructionKind dtorKind, Address addr, QualType type) {
+ CleanupKind cleanupKind = getCleanupKind(dtorKind);
+ pushLifetimeExtendedDestroy(cleanupKind, addr, type, getDestroyer(dtorKind),
+ cleanupKind & EHCleanup);
+}
+
void CodeGenFunction::pushDestroy(CleanupKind cleanupKind, Address addr,
QualType type, Destroyer *destroyer,
bool useEHCleanupForArray) {
- pushFullExprCleanup<DestroyObject>(cleanupKind, addr, type,
- destroyer, useEHCleanupForArray);
+ pushFullExprCleanup<DestroyObject>(cleanupKind, addr, type, destroyer,
+ useEHCleanupForArray);
}
// Pushes a destroy and defers its deactivation until its
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 451034395976f..62eaff4e6a978 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -393,55 +393,49 @@ pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
}
}
- CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
- if (const RecordType *RT =
- E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
- // Get the destructor for the reference temporary.
- auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
- if (!ClassDecl->hasTrivialDestructor())
- ReferenceTemporaryDtor = ClassDecl->getDestructor();
- }
+ QualType::DestructionKind DK = E->getType().isDestructedType();
+ if (DK != QualType::DK_none) {
+ switch (M->getStorageDuration()) {
+ case SD_Static:
+ case SD_Thread: {
+ CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
+ if (const RecordType *RT =
+ E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
+ // Get the destructor for the reference temporary.
+ if (auto *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl());
+ ClassDecl && !ClassDecl->hasTrivialDestructor())
+ ReferenceTemporaryDtor = ClassDecl->getDestructor();
+ }
- if (!ReferenceTemporaryDtor)
- return;
+ if (!ReferenceTemporaryDtor)
+ return;
- // Call the destructor for the temporary.
- switch (M->getStorageDuration()) {
- case SD_Static:
- case SD_Thread: {
- llvm::FunctionCallee CleanupFn;
- llvm::Constant *CleanupArg;
- if (E->getType()->isArrayType()) {
- CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
- ReferenceTemporary, E->getType(),
- CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions,
- dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
- CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
- } else {
- CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
- GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
- CleanupArg = cast<llvm::Constant>(ReferenceTemporary.emitRawPointer(CGF));
+ llvm::FunctionCallee CleanupFn;
+ llvm::Constant *CleanupArg;
+ if (E->getType()->isArrayType()) {
+ CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
+ ReferenceTemporary, E->getType(), CodeGenFunction::destroyCXXObject,
+ CGF.getLangOpts().Exceptions,
+ dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
+ CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
+ } else {
+ CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
+ GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
+ CleanupArg =
+ cast<llvm::Constant>(ReferenceTemporary.emitRawPointer(CGF));
+ }
+ CGF.CGM.getCXXABI().registerGlobalDtor(
+ CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
+ } break;
+ case SD_FullExpression:
+ CGF.pushDestroy(DK, ReferenceTemporary, E->getType());
+ break;
+ case SD_Automatic:
+ CGF.pushLifetimeExtendedDestroy(DK, ReferenceTemporary, E->getType());
+ break;
+ case SD_Dynamic:
+ llvm_unreachable("temporary cannot have dynamic storage duration");
}
- CGF.CGM.getCXXABI().registerGlobalDtor(
- CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
- break;
- }
-
- case SD_FullExpression:
- CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
- CodeGenFunction::destroyCXXObject,
- CGF.getLangOpts().Exceptions);
- break;
-
- case SD_Automatic:
- CGF.pushLifetimeExtendedDestroy(NormalAndEHCleanup,
- ReferenceTemporary, E->getType(),
- CodeGenFunction::destroyCXXObject,
- CGF.getLangOpts().Exceptions);
- break;
-
- case SD_Dynamic:
- llvm_unreachable("temporary cannot have dynamic storage duration");
}
}
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 2b1062d6d307c..a398ba55dcdc7 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -2249,6 +2249,8 @@ class CodeGenFunction : public CodeGenTypeCache {
void pushLifetimeExtendedDestroy(CleanupKind kind, Address addr,
QualType type, Destroyer *destroyer,
bool useEHCleanupForArray);
+ void pushLifetimeExtendedDestroy(QualType::DestructionKind dtorKind,
+ Address addr, QualType type);
void pushCallObjectDeleteCleanup(const FunctionDecl *OperatorDelete,
llvm::Value *CompletePtr,
QualType ElementType);
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 87a4244f2fb76..efe2d03882f31 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -7650,11 +7650,14 @@ Sema::CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary,
}
ExprResult Sema::TemporaryMaterializationConversion(Expr *E) {
- // In C++98, we don't want to implicitly create an xvalue.
+ // In C++98, we don't want to implicitly create an xvalue. C11 added the
+ // same rule, but C99 is broken without this behavior and so we treat the
+ // change as applying to all C language modes.
// FIXME: This means that AST consumers need to deal with "prvalues" that
// denote materialized temporaries. Maybe we should add another ValueKind
// for "xvalue pretending to be a prvalue" for C++98 support.
- if (!E->isPRValue() || !getLangOpts().CPlusPlus11)
+ if (!E->isPRValue() ||
+ (!getLangOpts().CPlusPlus11 && getLangOpts().CPlusPlus))
return E;
// C++1z [conv.rval]/1: T shall be a complete type.
diff --git a/clang/test/C/C11/n1285.c b/clang/test/C/C11/n1285.c
index e7a9463e68103..f89baa8d06eb2 100644
--- a/clang/test/C/C11/n1285.c
+++ b/clang/test/C/C11/n1285.c
@@ -1,24 +1,82 @@
-// RUN: %clang_cc1 -verify=wrong -std=c99 %s
-// RUN: %clang_cc1 -verify=wrong -std=c11 %s
-// RUN: %clang_cc1 -verify=cpp -std=c++11 -x c++ %s
+// RUN: %clang_cc1 -fsyntax-only -verify=expected,c -std=c99 %s
+// RUN: %clang_cc1 -fsyntax-only -verify=expected,c -std=c11 %s
+// RUN: %clang_cc1 -fsyntax-only -verify=expected,cpp -std=c++11 -x c++ %s
-/* WG14 N1285: No
+/* WG14 N1285: Clang 21
* Extending the lifetime of temporary objects (factored approach)
*
- * NB: we do not properly materialize temporary expressions in situations where
- * it would be expected; that is why the "no-diagnostics" marking is named
- * "wrong". We do issue the expected diagnostic in C++ mode.
+ * This paper introduced the notion of an object with a temporary lifetime. Any
+ * operation resulting in an rvalue of structure or union type which contains
+ * an array results in an object with temporary lifetime.
+ *
+ * Even though this is a change for C11, we treat it as a DR and apply it
+ * retroactively to earlier C language modes.
*/
-// wrong-no-diagnostics
+// C11 6.2.4p8: A non-lvalue expression with structure or union type, where the
+// structure or union contains a member with array type (including,
+// recursively, members of all contained structures and unions) refers to an
+// object with automatic storage duration and temporary lifetime. Its lifetime
+// begins when the expression is evaluated and its initial value is the value
+// of the expression. Its lifetime ends when the evaluation of the containing
+// full expression or full declarator ends. Any attempt to modify an object
+// with temporary lifetime results in undefined behavior.
struct X { int a[5]; };
struct X f(void);
-int foo(void) {
- // FIXME: This diagnostic should be issued in C11 as well (though not in C99,
- // as this paper was a breaking change between C99 and C11).
- int *p = f().a; // cpp-warning {{temporary whose address is used as value of local variable 'p' will be destroyed at the end of the full-expression}}
- return *p;
+union U { int a[10]; double d; };
+union U g(void);
+
+void sink(int *);
+
+int func_return(void) {
+ int *p = f().a; // expected-warning {{temporary whose address is used as value of local variable 'p' will be destroyed at the end of the full-expression}}
+ p = f().a; // expected-warning {{object backing the pointer p will be destroyed at the end of the full-expression}}
+ p = g().a; // expected-warning {{object backing the pointer p will be destroyed at the end of the full-expression}}
+ sink(f().a); // Ok
+ return *f().a; // Ok
+}
+
+int ternary(void) {
+ int *p = (1 ? (struct X){ 0 } : f()).a; // expected-warning {{temporary whose address is used as value of local variable 'p' will be destroyed at the end of the full-expression}}
+ int *r = (1 ? (union U){ 0 } : g()).a; // expected-warning {{temporary whose address is used as value of local variable 'r' will be destroyed at the end of the full-expression}}
+ p = (1 ? (struct X){ 0 } : f()).a; // expected-warning {{object backing the pointer p will be destroyed at the end of the full-expression}}
+ sink((1 ? (struct X){ 0 } : f()).a); // Ok
+
+ // This intentionally gets one diagnostic in C and two in C++. In C, the
+ // compound literal results in an lvalue, not an rvalue as it does in C++. So
+ // only one branch results in a temporary in C but both branches do in C++.
+ int *q = 1 ? (struct X){ 0 }.a : f().a; // expected-warning {{temporary whose address is used as value of local variable 'q' will be destroyed at the end of the full-expression}} \
+ cpp-warning {{temporary whose address is used as value of local variable 'q' will be destroyed at the end of the full-expression}}
+ q = 1 ? (struct X){ 0 }.a : f().a; // expected-warning {{object backing the pointer q will be destroyed at the end of the full-expression}} \
+ cpp-warning {{object backing the pointer q will be destroyed at the end of the full-expression}}
+ q = 1 ? (struct X){ 0 }.a : g().a; // expected-warning {{object backing the pointer q will be destroyed at the end of the full-expression}} \
+ cpp-warning {{object backing the pointer q will be destroyed at the end of the full-expression}}
+ sink(1 ? (struct X){ 0 }.a : f().a); // Ok
+ return *(1 ? (struct X){ 0 }.a : f().a); // Ok
}
+int comma(void) {
+ struct X x;
+ int *p = ((void)0, x).a; // c-warning {{temporary whose address is used as value of local variable 'p' will be destroyed at the end of the full-expression}}
+ p = ((void)0, x).a; // c-warning {{object backing the pointer p will be destroyed at the end of the full-expression}}
+ sink(((void)0, x).a); // Ok
+ return *(((void)0, x).a);// Ok
+}
+
+int cast(void) {
+ struct X x;
+ int *p = ((struct X)x).a; // expected-warning {{temporary whose address is used as value of local variable 'p' will be destroyed at the end of the full-expression}}
+ p = ((struct X)x).a; // expected-warning {{object backing the pointer p will be destroyed at the end of the full-expression}}
+ sink(((struct X)x).a); // Ok
+ return *(((struct X)x).a); // Ok
+}
+
+int assign(void) {
+ struct X x, s;
+ int *p = (x = s).a; // c-warning {{temporary whose address is used as value of local variable 'p' will be destroyed at the end of the full-expression}}
+ p = (x = s).a; // c-warning {{object backing the pointer p will be destroyed at the end of the full-expression}}
+ sink((x = s).a); // Ok
+ return *((x = s).a); // Ok
+}
diff --git a/clang/test/C/C11/n1285_1.c b/clang/test/C/C11/n1285_1.c
new file mode 100644
index 0000000000000..d2ba5cc8f2bc0
--- /dev/null
+++ b/clang/test/C/C11/n1285_1.c
@@ -0,0 +1,244 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 5
+// RUN: %clang_cc1 -std=c99 -Wno-dangling -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK
+// RUN: %clang_cc1 -std=c11 -Wno-dangling -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK
+// RUN: %clang_cc1 -std=c11 -O2 -disable-llvm-passes -Wno-dangling -emit-llvm -o - %s | FileCheck %s --check-prefix=C11-O2
+
+// Ensure that codegen for temporary lifetimes makes sense.
+
+struct X { int a[5]; };
+struct X f(void);
+
+// CHECK-LABEL: define dso_local i32 @func_return(
+// CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT: [[ENTRY:.*:]]
+// CHECK-NEXT: [[P:%.*]] = alloca ptr, align 8
+// CHECK-NEXT: [[REF_TMP:%.*]] = alloca [[STRUCT_X:%.*]], align 4
+// CHECK-NEXT: call void @f(ptr dead_on_unwind writable sret([[STRUCT_X]]) align 4 [[REF_TMP]])
+// CHECK-NEXT: [[A:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [5 x i32], ptr [[A]], i64 0, i64 0
+// CHECK-NEXT: store ptr [[ARRAYDECAY]], ptr [[P]], align 8
+// CHECK-NEXT: [[TMP0:%.*]] = load ptr, ptr [[P]], align 8
+// CHECK-NEXT: [[TMP1:%.*]] = load i32, ptr [[TMP0]], align 4
+// CHECK-NEXT: ret i32 [[TMP1]]
+//
+// C11-O2-LABEL: define dso_local i32 @func_return(
+// C11-O2-SAME: ) #[[ATTR0:[0-9]+]] {
+// C11-O2-NEXT: [[ENTRY:.*:]]
+// C11-O2-NEXT: [[P:%.*]] = alloca ptr, align 8
+// C11-O2-NEXT: [[REF_TMP:%.*]] = alloca [[STRUCT_X:%.*]], align 4
+// C11-O2-NEXT: call void @llvm.lifetime.start.p0(i64 8, ptr [[P]]) #[[ATTR5:[0-9]+]]
+// C11-O2-NEXT: call void @llvm.lifetime.start.p0(i64 20, ptr [[REF_TMP]]) #[[ATTR5]]
+// C11-O2-NEXT: call void @f(ptr dead_on_unwind writable sret([[STRUCT_X]]) align 4 [[REF_TMP]])
+// C11-O2-NEXT: [[A:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// C11-O2-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [5 x i32], ptr [[A]], i64 0, i64 0
+// C11-O2-NEXT: call void @llvm.lifetime.end.p0(i64 20, ptr [[REF_TMP]]) #[[ATTR5]]
+// C11-O2-NEXT: store ptr [[ARRAYDECAY]], ptr [[P]], align 8, !tbaa [[TBAA3:![0-9]+]]
+// C11-O2-NEXT: [[TMP0:%.*]] = load ptr, ptr [[P]], align 8, !tbaa [[TBAA3]]
+// C11-O2-NEXT: [[TMP1:%.*]] = load i32, ptr [[TMP0]], align 4, !tbaa [[TBAA8:![0-9]+]]
+// C11-O2-NEXT: call void @llvm.lifetime.end.p0(i64 8, ptr [[P]]) #[[ATTR5]]
+// C11-O2-NEXT: ret i32 [[TMP1]]
+//
+int func_return(void) {
+ int *p = f().a;
+ return *p;
+}
+
+// CHECK-LABEL: define dso_local i32 @ternary(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT: [[ENTRY:.*:]]
+// CHECK-NEXT: [[REF_TMP:%.*]] = alloca [[STRUCT_X:%.*]], align 4
+// CHECK-NEXT: [[Q:%.*]] = alloca ptr, align 8
+// CHECK-NEXT: [[DOTCOMPOUNDLITERAL:%.*]] = alloca [[STRUCT_X]], align 4
+// CHECK-NEXT: br i1 true, label %[[COND_TRUE:.*]], label %[[COND_FALSE:.*]]
+// CHECK: [[COND_TRUE]]:
+// CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 4 [[REF_TMP]], i8 0, i64 20, i1 false)
+// CHECK-NEXT: [[A:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// CHECK-NEXT: br label %[[COND_END:.*]]
+// CHECK: [[COND_FALSE]]:
+// CHECK-NEXT: call void @f(ptr dead_on_unwind writable sret([[STRUCT_X]]) align 4 [[REF_TMP]])
+// CHECK-NEXT: br label %[[COND_END]]
+// CHECK: [[COND_END]]:
+// CHECK-NEXT: [[A1:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [5 x i32], ptr [[A1]], i64 0, i64 0
+// CHECK-NEXT: store ptr [[ARRAYDECAY]], ptr @p, align 8
+// CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 4 [[DOTCOMPOUNDLITERAL]], i8 0, i64 20, i1 false)
+// CHECK-NEXT: [[A2:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[DOTCOMPOUNDLITERAL]], i32 0, i32 0
+// CHECK-NEXT: [[A3:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[DOTCOMPOUNDLITERAL]], i32 0, i32 0
+// CHECK-NEXT: [[ARRAYDECAY4:%.*]] = getelementptr inbounds [5 x i32], ptr [[A3]], i64 0, i64 0
+// CHECK-NEXT: store ptr [[ARRAYDECAY4]], ptr [[Q]], align 8
+// CHECK-NEXT: [[TMP0:%.*]] = load ptr, ptr @p, align 8
+// CHECK-NEXT: [[TMP1:%.*]] = load i32, ptr [[TMP0]], align 4
+// CHECK-NEXT: [[TMP2:%.*]] = load ptr, ptr [[Q]], align 8
+// CHECK-NEXT: [[TMP3:%.*]] = load i32, ptr [[TMP2]], align 4
+// CHECK-NEXT: [[ADD:%.*]] = add nsw i32 [[TMP1]], [[TMP3]]
+// CHECK-NEXT: ret i32 [[ADD]]
+//
+// C11-O2-LABEL: define dso_local i32 @ternary(
+// C11-O2-SAME: ) #[[ATTR0]] {
+// C11-O2-NEXT: [[ENTRY:.*:]]
+// C11-O2-NEXT: [[REF_TMP:%.*]] = alloca [[STRUCT_X:%.*]], align 4
+// C11-O2-NEXT: [[Q:%.*]] = alloca ptr, align 8
+// C11-O2-NEXT: [[DOTCOMPOUNDLITERAL:%.*]] = alloca [[STRUCT_X]], align 4
+// C11-O2-NEXT: call void @llvm.lifetime.start.p0(i64 20, ptr [[REF_TMP]]) #[[ATTR5]]
+// C11-O2-NEXT: br i1 true, label %[[COND_TRUE:.*]], label %[[COND_FALSE:.*]]
+// C11-O2: [[COND_TRUE]]:
+// C11-O2-NEXT: call void @llvm.memset.p0.i64(ptr align 4 [[REF_TMP]], i8 0, i64 20, i1 false)
+// C11-O2-NEXT: [[A:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// C11-O2-NEXT: br label %[[COND_END:.*]]
+// C11-O2: [[COND_FALSE]]:
+// C11-O2-NEXT: call void @f(ptr dead_on_unwind writable sret([[STRUCT_X]]) align 4 [[REF_TMP]])
+// C11-O2-NEXT: br label %[[COND_END]]
+// C11-O2: [[COND_END]]:
+// C11-O2-NEXT: [[A1:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// C11-O2-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [5 x i32], ptr [[A1]], i64 0, i64 0
+// C11-O2-NEXT: store ptr [[ARRAYDECAY]], ptr @p, align 8, !tbaa [[TBAA3]]
+// C11-O2-NEXT: call void @llvm.lifetime.end.p0(i64 20, ptr [[REF_TMP]]) #[[ATTR5]]
+// C11-O2-NEXT: call void @llvm.lifetime.start.p0(i64 8, ptr [[Q]]) #[[ATTR5]]
+// C11-O2-NEXT: call void @llvm.memset.p0.i64(ptr align 4 [[DOTCOMPOUNDLITERAL]], i8 0, i64 20, i1 false)
+// C11-O2-NEXT: [[A2:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[DOTCOMPOUNDLITERAL]], i32 0, i32 0
+// C11-O2-NEXT: [[A3:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[DOTCOMPOUNDLITERAL]], i32 0, i32 0
+// C11-O2-NEXT: [[ARRAYDECAY4:%.*]] = getelementptr inbounds [5 x i32], ptr [[A3]], i64 0, i64 0
+// C11-O2-NEXT: store ptr [[ARRAYDECAY4]], ptr [[Q]], align 8, !tbaa [[TBAA3]]
+// C11-O2-NEXT: [[TMP0:%.*]] = load ptr, ptr @p, align 8, !tbaa [[TBAA3]]
+// C11-O2-NEXT: [[TMP1:%.*]] = load i32, ptr [[TMP0]], align 4, !tbaa [[TBAA8]]
+// C11-O2-NEXT: [[TMP2:%.*]] = load ptr, ptr [[Q]], align 8, !tbaa [[TBAA3]]
+// C11-O2-NEXT: [[TMP3:%.*]] = load i32, ptr [[TMP2]], align 4, !tbaa [[TBAA8]]
+// C11-O2-NEXT: [[ADD:%.*]] = add nsw i32 [[TMP1]], [[TMP3]]
+// C11-O2-NEXT: call void @llvm.lifetime.end.p0(i64 8, ptr [[Q]]) #[[ATTR5]]
+// C11-O2-NEXT: ret i32 [[ADD]]
+//
+int ternary(void) {
+ extern int *p;
+ p = (1 ? (struct X){ 0 } : f()).a;
+ int *q = 1 ? (struct X){ 0 }.a : f().a;
+
+ return *p + *q;
+}
+
+// CHECK-LABEL: define dso_local i32 @comma(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT: [[ENTRY:.*:]]
+// CHECK-NEXT: [[X:%.*]] = alloca [[STRUCT_X:%.*]], align 4
+// CHECK-NEXT: [[REF_TMP:%.*]] = alloca [[STRUCT_X]], align 4
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 4 [[REF_TMP]], ptr align 4 [[X]], i64 20, i1 false)
+// CHECK-NEXT: [[A:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [5 x i32], ptr [[A]], i64 0, i64 0
+// CHECK-NEXT: store ptr [[ARRAYDECAY]], ptr @p, align 8
+// CHECK-NEXT: [[TMP0:%.*]] = load ptr, ptr @p, align 8
+// CHECK-NEXT: [[TMP1:%.*]] = load i32, ptr [[TMP0]], align 4
+// CHECK-NEXT: ret i32 [[TMP1]]
+//
+// C11-O2-LABEL: define dso_local i32 @comma(
+// C11-O2-SAME: ) #[[ATTR0]] {
+// C11-O2-NEXT: [[ENTRY:.*:]]
+// C11-O2-NEXT: [[X:%.*]] = alloca [[STRUCT_X:%.*]], align 4
+// C11-O2-NEXT: [[REF_TMP:%.*]] = alloca [[STRUCT_X]], align 4
+// C11-O2-NEXT: call void @llvm.lifetime.start.p0(i64 20, ptr [[X]]) #[[ATTR5]]
+// C11-O2-NEXT: call void @llvm.lifetime.start.p0(i64 20, ptr [[REF_TMP]]) #[[ATTR5]]
+// C11-O2-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 4 [[REF_TMP]], ptr align 4 [[X]], i64 20, i1 false), !tbaa.struct [[TBAA_STRUCT10:![0-9]+]]
+// C11-O2-NEXT: [[A:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// C11-O2-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [5 x i32], ptr [[A]], i64 0, i64 0
+// C11-O2-NEXT: store ptr [[ARRAYDECAY]], ptr @p, align 8, !tbaa [[TBAA3]]
+// C11-O2-NEXT: call void @llvm.lifetime.end.p0(i64 20, ptr [[REF_TMP]]) #[[ATTR5]]
+// C11-O2-NEXT: [[TMP0:%.*]] = load ptr, ptr @p, align 8, !tbaa [[TBAA3]]
+// C11-O2-NEXT: [[TMP1:%.*]] = load i32, ptr [[TMP0]], align 4, !tbaa [[TBAA8]]
+// C11-O2-NEXT: call void @llvm.lifetime.end.p0(i64 20, ptr [[X]]) #[[ATTR5]]
+// C11-O2-NEXT: ret i32 [[TMP1]]
+//
+int comma(void) {
+ struct X x;
+ extern int *p;
+ p = ((void)0, x).a;
+ return *p;
+}
+
+// CHECK-LABEL: define dso_local i32 @cast(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT: [[ENTRY:.*:]]
+// CHECK-NEXT: [[X:%.*]] = alloca [[STRUCT_X:%.*]], align 4
+// CHECK-NEXT: [[REF_TMP:%.*]] = alloca [[STRUCT_X]], align 4
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 4 [[REF_TMP]], ptr align 4 [[X]], i64 20, i1 false)
+// CHECK-NEXT: [[A:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [5 x i32], ptr [[A]], i64 0, i64 0
+// CHECK-NEXT: store ptr [[ARRAYDECAY]], ptr @p, align 8
+// CHECK-NEXT: [[TMP0:%.*]] = load ptr, ptr @p, align 8
+// CHECK-NEXT: [[TMP1:%.*]] = load i32, ptr [[TMP0]], align 4
+// CHECK-NEXT: ret i32 [[TMP1]]
+//
+// C11-O2-LABEL: define dso_local i32 @cast(
+// C11-O2-SAME: ) #[[ATTR0]] {
+// C11-O2-NEXT: [[ENTRY:.*:]]
+// C11-O2-NEXT: [[X:%.*]] = alloca [[STRUCT_X:%.*]], align 4
+// C11-O2-NEXT: [[REF_TMP:%.*]] = alloca [[STRUCT_X]], align 4
+// C11-O2-NEXT: call void @llvm.lifetime.start.p0(i64 20, ptr [[X]]) #[[ATTR5]]
+// C11-O2-NEXT: call void @llvm.lifetime.start.p0(i64 20, ptr [[REF_TMP]]) #[[ATTR5]]
+// C11-O2-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 4 [[REF_TMP]], ptr align 4 [[X]], i64 20, i1 false), !tbaa.struct [[TBAA_STRUCT10]]
+// C11-O2-NEXT: [[A:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// C11-O2-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [5 x i32], ptr [[A]], i64 0, i64 0
+// C11-O2-NEXT: store ptr [[ARRAYDECAY]], ptr @p, align 8, !tbaa [[TBAA3]]
+// C11-O2-NEXT: call void @llvm.lifetime.end.p0(i64 20, ptr [[REF_TMP]]) #[[ATTR5]]
+// C11-O2-NEXT: [[TMP0:%.*]] = load ptr, ptr @p, align 8, !tbaa [[TBAA3]]
+// C11-O2-NEXT: [[TMP1:%.*]] = load i32, ptr [[TMP0]], align 4, !tbaa [[TBAA8]]
+// C11-O2-NEXT: call void @llvm.lifetime.end.p0(i64 20, ptr [[X]]) #[[ATTR5]]
+// C11-O2-NEXT: ret i32 [[TMP1]]
+//
+int cast(void) {
+ struct X x;
+ extern int *p;
+ p = ((struct X)x).a;
+ return *p;
+}
+
+// CHECK-LABEL: define dso_local i32 @assign(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT: [[ENTRY:.*:]]
+// CHECK-NEXT: [[X:%.*]] = alloca [[STRUCT_X:%.*]], align 4
+// CHECK-NEXT: [[S:%.*]] = alloca [[STRUCT_X]], align 4
+// CHECK-NEXT: [[REF_TMP:%.*]] = alloca [[STRUCT_X]], align 4
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 4 [[X]], ptr align 4 [[S]], i64 20, i1 false)
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 4 [[REF_TMP]], ptr align 4 [[X]], i64 20, i1 false)
+// CHECK-NEXT: [[A:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [5 x i32], ptr [[A]], i64 0, i64 0
+// CHECK-NEXT: store ptr [[ARRAYDECAY]], ptr @p, align 8
+// CHECK-NEXT: [[TMP0:%.*]] = load ptr, ptr @p, align 8
+// CHECK-NEXT: [[TMP1:%.*]] = load i32, ptr [[TMP0]], align 4
+// CHECK-NEXT: ret i32 [[TMP1]]
+//
+// C11-O2-LABEL: define dso_local i32 @assign(
+// C11-O2-SAME: ) #[[ATTR0]] {
+// C11-O2-NEXT: [[ENTRY:.*:]]
+// C11-O2-NEXT: [[X:%.*]] = alloca [[STRUCT_X:%.*]], align 4
+// C11-O2-NEXT: [[S:%.*]] = alloca [[STRUCT_X]], align 4
+// C11-O2-NEXT: [[REF_TMP:%.*]] = alloca [[STRUCT_X]], align 4
+// C11-O2-NEXT: call void @llvm.lifetime.start.p0(i64 20, ptr [[X]]) #[[ATTR5]]
+// C11-O2-NEXT: call void @llvm.lifetime.start.p0(i64 20, ptr [[S]]) #[[ATTR5]]
+// C11-O2-NEXT: call void @llvm.lifetime.start.p0(i64 20, ptr [[REF_TMP]]) #[[ATTR5]]
+// C11-O2-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 4 [[X]], ptr align 4 [[S]], i64 20, i1 false), !tbaa.struct [[TBAA_STRUCT10]]
+// C11-O2-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 4 [[REF_TMP]], ptr align 4 [[X]], i64 20, i1 false), !tbaa.struct [[TBAA_STRUCT10]]
+// C11-O2-NEXT: [[A:%.*]] = getelementptr inbounds nuw [[STRUCT_X]], ptr [[REF_TMP]], i32 0, i32 0
+// C11-O2-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [5 x i32], ptr [[A]], i64 0, i64 0
+// C11-O2-NEXT: store ptr [[ARRAYDECAY]], ptr @p, align 8, !tbaa [[TBAA3]]
+// C11-O2-NEXT: call void @llvm.lifetime.end.p0(i64 20, ptr [[REF_TMP]]) #[[ATTR5]]
+// C11-O2-NEXT: [[TMP0:%.*]] = load ptr, ptr @p, align 8, !tbaa [[TBAA3]]
+// C11-O2-NEXT: [[TMP1:%.*]] = load i32, ptr [[TMP0]], align 4, !tbaa [[TBAA8]]
+// C11-O2-NEXT: call void @llvm.lifetime.end.p0(i64 20, ptr [[S]]) #[[ATTR5]]
+// C11-O2-NEXT: call void @llvm.lifetime.end.p0(i64 20, ptr [[X]]) #[[ATTR5]]
+// C11-O2-NEXT: ret i32 [[TMP1]]
+//
+int assign(void) {
+ struct X x, s;
+ extern int *p;
+ p = (x = s).a;
+ return *p;
+}
+//.
+// C11-O2: [[TBAA3]] = !{[[META4:![0-9]+]], [[META4]], i64 0}
+// C11-O2: [[META4]] = !{!"p1 int", [[META5:![0-9]+]], i64 0}
+// C11-O2: [[META5]] = !{!"any pointer", [[META6:![0-9]+]], i64 0}
+// C11-O2: [[META6]] = !{!"omnipotent char", [[META7:![0-9]+]], i64 0}
+// C11-O2: [[META7]] = !{!"Simple C/C++ TBAA"}
+// C11-O2: [[TBAA8]] = !{[[META9:![0-9]+]], [[META9]], i64 0}
+// C11-O2: [[META9]] = !{!"int", [[META6]], i64 0}
+// C11-O2: [[TBAA_STRUCT10]] = !{i64 0, i64 20, [[META11:![0-9]+]]}
+// C11-O2: [[META11]] = !{[[META6]], [[META6]], i64 0}
+//.
diff --git a/clang/test/CodeGen/xcore-abi.c b/clang/test/CodeGen/xcore-abi.c
index 40e2f418f7304..a8c563c3d2fab 100644
--- a/clang/test/CodeGen/xcore-abi.c
+++ b/clang/test/CodeGen/xcore-abi.c
@@ -27,7 +27,7 @@ void testva (int n, ...) {
va_start(ap,n);
// CHECK: [[AP:%[a-z0-9]+]] = alloca ptr, align 4
// CHECK: [[V5:%[a-z0-9]+]] = alloca %struct.x, align 4
- // CHECK: [[TMP:%[a-z0-9]+]] = alloca [4 x i32], align 4
+ // CHECK: [[TMP:%[a-z0-9.]+]] = alloca [4 x i32], align 4
// CHECK: call void @llvm.va_start.p0(ptr [[AP]])
char* v1 = va_arg (ap, char*);
diff --git a/clang/test/CodeGenObjC/property-array-type.m b/clang/test/CodeGenObjC/property-array-type.m
index a0ad8db2630fa..3bb1e3c63334e 100644
--- a/clang/test/CodeGenObjC/property-array-type.m
+++ b/clang/test/CodeGenObjC/property-array-type.m
@@ -23,7 +23,8 @@ - (void)viewDidLoad {
}
@end
-// CHECK: [[M:%.*]] = getelementptr inbounds nuw %struct._GLKMatrix4, ptr [[TMP:%.*]], i32 0, i32 0
+// CHECK: [[REF_TEMP:%.*]] = alloca %struct._GLKMatrix4, align 4
+// CHECK: [[M:%.*]] = getelementptr inbounds nuw %struct._GLKMatrix4, ptr [[REF_TEMP:%.*]], i32 0, i32 0
// CHECK: [[ARRAYDECAY:%.*]] = getelementptr inbounds [16 x float], ptr [[M]], i64 0, i64 0
// CHECK: [[SIX:%.*]] = load ptr, ptr @OBJC_SELECTOR_REFERENCES
-// CHECK: call void @objc_msgSend(ptr noundef [[SEVEN:%.*]], ptr noundef [[SIX]], ptr noundef [[ARRAYDECAY]])
+// CHECK: call void @objc_msgSend(ptr noundef [[SEVEN:%.*]], ptr noundef [[SIX]], ptr noundef [[ARRAYDECAY]])
diff --git a/clang/www/c_status.html b/clang/www/c_status.html
index 8434ed9ecf6f8..af1b61afdaec8 100644
--- a/clang/www/c_status.html
+++ b/clang/www/c_status.html
@@ -941,7 +941,7 @@ <h2 id="c11">C11 implementation status</h2>
<tr>
<td>Extending the lifetime of temporary objects (factored approach)</td>
<td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1285.htm">N1285</a></td>
- <td class="none" align="center">No</td>
+ <td class="unreleased" align="center">Clang 21</td>
</tr>
<tr>
<td>Requiring signed char to have no padding bits</td>
More information about the cfe-commits
mailing list