[clang] Fix parenthesized list initialization of arrays not working w…

…ith `new` (#76976) This bug is caused by parenthesized list initialization not being implemented in `CodeGenFunction::EmitNewArrayInitializer(...)`. Parenthesized list initialization of `struct`s with `operator new` already works in Clang and is not affected by this bug. Additionally, fix the test new-delete.cpp as it incorrectly assumes that using parentheses with operator new to initialize arrays is illegal for C++ versions >= C++17. Fixes #68198
llvm · Jan 18, 2024 · 2c9f04c · 2c9f04c
1 parent 5de1d00
commit 2c9f04c
Show file tree

Hide file tree

Showing 7 changed files with 221 additions and 33 deletions.
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
@@ -976,6 +976,9 @@ Bug Fixes to C++ Support
   ``std::source_location::current()`` was used in a function template.
   Fixes (`#78128 <https://github.com/llvm/llvm-project/issues/78128>`_)
 
+- Clang now allows parenthesized initialization of arrays in `operator new[]`.
+  Fixes: (`#68198 <https://github.com/llvm/llvm-project/issues/68198>`_)
+
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
 - Fixed an import failure of recursive friend class template.

diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp
@@ -1038,11 +1038,25 @@ void CodeGenFunction::EmitNewArrayInitializer(
     return true;
   };
 
+  const InitListExpr *ILE = dyn_cast<InitListExpr>(Init);
+  const CXXParenListInitExpr *CPLIE = nullptr;
+  const StringLiteral *SL = nullptr;
+  const ObjCEncodeExpr *OCEE = nullptr;
+  const Expr *IgnoreParen = nullptr;
+  if (!ILE) {
+    IgnoreParen = Init->IgnoreParenImpCasts();
+    CPLIE = dyn_cast<CXXParenListInitExpr>(IgnoreParen);
+    SL = dyn_cast<StringLiteral>(IgnoreParen);
+    OCEE = dyn_cast<ObjCEncodeExpr>(IgnoreParen);
+  }
+
   // If the initializer is an initializer list, first do the explicit elements.
-  if (const InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
+  if (ILE || CPLIE || SL || OCEE) {
     // Initializing from a (braced) string literal is a special case; the init
     // list element does not initialize a (single) array element.
-    if (ILE->isStringLiteralInit()) {
+    if ((ILE && ILE->isStringLiteralInit()) || SL || OCEE) {
+      if (!ILE)
+        Init = IgnoreParen;
       // Initialize the initial portion of length equal to that of the string
       // literal. The allocation must be for at least this much; we emitted a
       // check for that earlier.
@@ -1054,12 +1068,13 @@ void CodeGenFunction::EmitNewArrayInitializer(
                                 AggValueSlot::DoesNotOverlap,
                                 AggValueSlot::IsNotZeroed,
                                 AggValueSlot::IsSanitizerChecked);
-      EmitAggExpr(ILE->getInit(0), Slot);
+      EmitAggExpr(ILE ? ILE->getInit(0) : Init, Slot);
 
       // Move past these elements.
       InitListElements =
-          cast<ConstantArrayType>(ILE->getType()->getAsArrayTypeUnsafe())
-              ->getSize().getZExtValue();
+          cast<ConstantArrayType>(Init->getType()->getAsArrayTypeUnsafe())
+              ->getSize()
+              .getZExtValue();
       CurPtr = Builder.CreateConstInBoundsGEP(
           CurPtr, InitListElements, "string.init.end");
 
@@ -1073,7 +1088,9 @@ void CodeGenFunction::EmitNewArrayInitializer(
       return;
     }
 
-    InitListElements = ILE->getNumInits();
+    ArrayRef<const Expr *> InitExprs =
+        ILE ? ILE->inits() : CPLIE->getInitExprs();
+    InitListElements = InitExprs.size();
 
     // If this is a multi-dimensional array new, we will initialize multiple
     // elements with each init list element.
@@ -1101,7 +1118,8 @@ void CodeGenFunction::EmitNewArrayInitializer(
     }
 
     CharUnits StartAlign = CurPtr.getAlignment();
-    for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) {
+    unsigned i = 0;
+    for (const Expr *IE : InitExprs) {
       // Tell the cleanup that it needs to destroy up to this
       // element.  TODO: some of these stores can be trivially
       // observed to be unnecessary.
@@ -1111,18 +1129,17 @@ void CodeGenFunction::EmitNewArrayInitializer(
       // FIXME: If the last initializer is an incomplete initializer list for
       // an array, and we have an array filler, we can fold together the two
       // initialization loops.
-      StoreAnyExprIntoOneUnit(*this, ILE->getInit(i),
-                              ILE->getInit(i)->getType(), CurPtr,
+      StoreAnyExprIntoOneUnit(*this, IE, IE->getType(), CurPtr,
                               AggValueSlot::DoesNotOverlap);
       CurPtr = Address(Builder.CreateInBoundsGEP(
                            CurPtr.getElementType(), CurPtr.getPointer(),
                            Builder.getSize(1), "array.exp.next"),
                        CurPtr.getElementType(),
-                       StartAlign.alignmentAtOffset((i + 1) * ElementSize));
+                       StartAlign.alignmentAtOffset((++i) * ElementSize));
     }
 
     // The remaining elements are filled with the array filler expression.
-    Init = ILE->getArrayFiller();
+    Init = ILE ? ILE->getArrayFiller() : CPLIE->getArrayFiller();
 
     // Extract the initializer for the individual array elements by pulling
     // out the array filler from all the nested initializer lists. This avoids
@@ -1561,16 +1578,23 @@ llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
   // 1. Build a call to the allocation function.
   FunctionDecl *allocator = E->getOperatorNew();
 
-  // If there is a brace-initializer, cannot allocate fewer elements than inits.
+  // If there is a brace-initializer or C++20 parenthesized initializer, cannot
+  // allocate fewer elements than inits.
   unsigned minElements = 0;
   if (E->isArray() && E->hasInitializer()) {
-    const InitListExpr *ILE = dyn_cast<InitListExpr>(E->getInitializer());
-    if (ILE && ILE->isStringLiteralInit())
+    const Expr *Init = E->getInitializer();
+    const InitListExpr *ILE = dyn_cast<InitListExpr>(Init);
+    const CXXParenListInitExpr *CPLIE = dyn_cast<CXXParenListInitExpr>(Init);
+    const Expr *IgnoreParen = Init->IgnoreParenImpCasts();
+    if ((ILE && ILE->isStringLiteralInit()) ||
+        isa<StringLiteral>(IgnoreParen) || isa<ObjCEncodeExpr>(IgnoreParen)) {
       minElements =
-          cast<ConstantArrayType>(ILE->getType()->getAsArrayTypeUnsafe())
-              ->getSize().getZExtValue();
-    else if (ILE)
-      minElements = ILE->getNumInits();
+          cast<ConstantArrayType>(Init->getType()->getAsArrayTypeUnsafe())
+              ->getSize()
+              .getZExtValue();
+    } else if (ILE || CPLIE) {
+      minElements = ILE ? ILE->getNumInits() : CPLIE->getInitExprs().size();
+    }
   }
 
   llvm::Value *numElements = nullptr;

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
@@ -1947,11 +1947,11 @@ Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
 }
 
 static bool isLegalArrayNewInitializer(CXXNewInitializationStyle Style,
-                                       Expr *Init) {
+                                       Expr *Init, bool IsCPlusPlus20) {
   if (!Init)
     return true;
   if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init))
-    return PLE->getNumExprs() == 0;
+    return IsCPlusPlus20 || PLE->getNumExprs() == 0;
   if (isa<ImplicitValueInitExpr>(Init))
     return true;
   else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init))
@@ -2406,7 +2406,8 @@ ExprResult Sema::BuildCXXNew(SourceRange Range, bool UseGlobal,
   // Array 'new' can't have any initializers except empty parentheses.
   // Initializer lists are also allowed, in C++11. Rely on the parser for the
   // dialect distinction.
-  if (ArraySize && !isLegalArrayNewInitializer(InitStyle, Initializer)) {
+  if (ArraySize && !isLegalArrayNewInitializer(InitStyle, Initializer,
+                                               getLangOpts().CPlusPlus20)) {
     SourceRange InitRange(Exprs.front()->getBeginLoc(),
                           Exprs.back()->getEndLoc());
     Diag(StartLoc, diag::err_new_array_init_args) << InitRange;

diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
@@ -5496,7 +5496,7 @@ static void TryOrBuildParenListInitialization(
         return;
     }
     //   ...and value-initialized for each k < i <= n;
-    if (ArrayLength > Args.size()) {
+    if (ArrayLength > Args.size() || Entity.isVariableLengthArrayNew()) {
       InitializedEntity SubEntity = InitializedEntity::InitializeElement(
           S.getASTContext(), Args.size(), Entity);
       InitializationKind SubKind = InitializationKind::CreateValue(

diff --git a/clang/test/CodeGen/paren-list-agg-init.cpp b/clang/test/CodeGen/paren-list-agg-init.cpp
@@ -513,3 +513,60 @@ namespace gh61567 {
     I(0);
   }
 }
+
+namespace gh68198 {
+  // CHECK: define {{.*}} void @{{.*foo25.*}} {
+  // CHECK-NEXT: entry
+  // CHECK-NEXT: [[ARR_8:%.*arr8.*]] = alloca ptr, align 8
+  // CHECK-NEXT: [[CALL_PTR:%.*]] = call noalias noundef nonnull ptr @_Znam(i64 noundef 8)
+  // CHECK-NEXT: store i32 1, ptr [[CALL_PTR]], align 4
+  // CHECK-NEXT: [[ARRAY_EXP_NEXT:%.*]] = getelementptr inbounds i32, ptr [[CALL_PTR]], i64 1
+  // CHECK-NEXT: store i32 2, ptr [[ARRAY_EXP_NEXT]], align 4
+  // CHECK-NEXT: [[ARRAY_EXP_NEXT1:%.*]] = getelementptr inbounds i32, ptr [[ARRAY_EXP_NEXT]], i64 1
+  // CHECK-NEXT: store ptr [[CALL_PTR]], ptr %arr8, align 8
+  // CHECK-NEXT: ret void
+  void foo25() {
+    int* arr8 = new int[](1, 2);
+  }
+
+  // CHECK: define {{.*}} void @{{.*foo26.*}} {
+  // CHECK-NEXT: entry
+  // CHECK-NEXT: [[ARR_10:%.*arr9.*]] = alloca ptr, align 8
+  // CHECK-NEXT: [[CALL_PTR]] = call noalias noundef nonnull ptr @_Znam(i64 noundef 16)
+  // CHECK-NEXT: [[ARRAYINIT_BEGIN:%.*]] = getelementptr inbounds [2 x i32], ptr [[CALL]], i64 0, i64 0
+  // CHECK-NEXT: store i32 1, ptr [[ARRAYINIT_BEGIN]], align 4
+  // CHECK-NEXT: [[ARRAYINIT_ELEMENT:%.*]] = getelementptr inbounds i32, ptr [[ARRAYINIT_BEGIN]], i64 1
+  // CHECK-NEXT: store i32 2, ptr [[ARRAYINIT_ELEMENT]], align 4
+  // CHECK-NEXT: [[ARRAY_EXP_NEXT:%.*]] = getelementptr inbounds [2 x i32], ptr %call, i64 1
+  // CHECK-NEXT: [[ARRAYINIT_BEGIN1:%.*]] = getelementptr inbounds [2 x i32], ptr [[ARRAY_EXP_NEXT]], i64 0, i64 0
+  // CHECK-NEXT: store i32 3, ptr [[ARRAYINIT_BEGIN1]], align 4
+  // CHECK-NEXT: [[ARRAYINIT_ELEMENT2:%.*]] = getelementptr inbounds i32, ptr [[ARRAYINIT_BEGIN1]], i64 1
+  // CHECK-NEXT: store i32 4, ptr [[ARRAYINIT_ELEMENT2]], align 4
+  // CHECK-NEXT: [[ARRAY_EXP_NEXT3:%.*]] = getelementptr inbounds [2 x i32], ptr [[ARRAY_EXP_NEXT]], i64 1
+  // CHECK-NEXT: store ptr [[CALL_PTR]], ptr [[ARR_10]], align 8
+  // CHECK-NEXT: ret void
+  void foo26() {
+    void* arr9 = new int[][2]({1, 2}, {3, 4});
+  }
+
+  // CHECK: define {{.*}} void @{{.*foo27.*}} {
+  // CHECK-NEXT: entry
+  // CHECK-NEXT: [[ARR_10:%.*arr10.*]] = alloca ptr, align 8
+  // CHECK-NEXT: [[CALL_PTR]] = call noalias noundef nonnull ptr @_Znam(i64 noundef 32)
+  // CHECK-NEXT: [[ARRAYINIT_BEGIN:%.*]] = getelementptr inbounds [2 x i32], ptr [[CALL]], i64 0, i64 0
+  // CHECK-NEXT: store i32 5, ptr [[ARRAYINIT_BEGIN]], align 4
+  // CHECK-NEXT: [[ARRAYINIT_ELEMENT:%.*]] = getelementptr inbounds i32, ptr [[ARRAYINIT_BEGIN]], i64 1
+  // CHECK-NEXT: store i32 6, ptr [[ARRAYINIT_ELEMENT]], align 4
+  // CHECK-NEXT: [[ARRAY_EXP_NEXT:%.*]] = getelementptr inbounds [2 x i32], ptr %call, i64 1
+  // CHECK-NEXT: [[ARRAYINIT_BEGIN1:%.*]] = getelementptr inbounds [2 x i32], ptr [[ARRAY_EXP_NEXT]], i64 0, i64 0
+  // CHECK-NEXT: store i32 7, ptr [[ARRAYINIT_BEGIN1]], align 4
+  // CHECK-NEXT: [[ARRAYINIT_ELEMENT2:%.*]] = getelementptr inbounds i32, ptr [[ARRAYINIT_BEGIN1]], i64 1
+  // CHECK-NEXT: store i32 8, ptr [[ARRAYINIT_ELEMENT2]], align 4
+  // CHECK-NEXT: [[ARRAY_EXP_NEXT3:%.*]] = getelementptr inbounds [2 x i32], ptr [[ARRAY_EXP_NEXT]], i64 1
+  // CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 4 [[ARRAY_EXP_NEXT3]], i8 0, i64 16, i1 false)
+  // CHECK-NEXT: store ptr [[CALL_PTR]], ptr [[ARR_10]], align 8
+  // CHECK-NEXT: ret void
+  void foo27() {
+    void* arr10 = new int[4][2]({5, 6}, {7, 8});
+  }
+}
diff --git a/clang/test/CodeGenCXX/new-array-init.cpp b/clang/test/CodeGenCXX/new-array-init.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++11 -triple i386-unknown-unknown %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -std=c++20 -triple i386-unknown-unknown %s -emit-llvm -o - | FileCheck %s --check-prefix=CHECK --check-prefix=CHECKCXX20
 // RUN: %clang_cc1 -std=c++11 -triple i386-unknown-unknown %s -emit-llvm -fsanitize=signed-integer-overflow -o - | FileCheck --check-prefix=SIO %s
 
 // CHECK: @[[ABC4:.*]] = {{.*}} constant [4 x i8] c"abc\00"
@@ -15,20 +16,51 @@ void fn(int n) {
   new int[n] { 1, 2, 3 };
 }
 
+#if __cplusplus >= 202002L
+// CHECKCXX20-LABEL: define{{.*}} void @_Z8fn_pareni
+void fn_paren(int n) {
+  // CHECKCXX20: icmp ult i{{32|64}} %{{[^ ]+}}, 3
+  // CHECKCXX20: store i32 1
+  // CHECKCXX20: store i32 2
+  // CHECKCXX20: store i32 3
+  // CHECKCXX20: sub {{.*}}, 12
+  // CHECKCXX20: call void @llvm.memset
+  new int[n](1, 2, 3);
+}
+#endif
+
 // CHECK-LABEL: define{{.*}} void @_Z11const_exactv
 void const_exact() {
   // CHECK-NOT: icmp ult i{{32|64}} %{{[^ ]+}}, 3
   // CHECK-NOT: icmp eq ptr
   new int[3] { 1, 2, 3 };
 }
 
+#if __cplusplus >= 202002L
+// CHECKCXX20-LABEL: define{{.*}} void @_Z17const_exact_parenv
+void const_exact_paren() {
+  // CHECKCXX20-NOT: icmp ult i{{32|64}} %{{[^ ]+}}, 3
+  // CHECKCXX20-NOT: icmp eq ptr
+  new int[3](1, 2, 3);
+}
+#endif
+
 // CHECK-LABEL: define{{.*}} void @_Z16const_sufficientv
 void const_sufficient() {
   // CHECK-NOT: icmp ult i{{32|64}} %{{[^ ]+}}, 3
   new int[4] { 1, 2, 3 };
   // CHECK: ret void
 }
 
+#if __cplusplus >= 202002L
+// CHECKCXX20-LABEL: define{{.*}} void @_Z22const_sufficient_parenv
+void const_sufficient_paren() {
+  // CHECKCXX20-NOT: icmp ult i{{32|64}} %{{[^ ]+}}, 3
+  new int[4](1, 2, 3);
+  // CHECKCXX20: ret void
+}
+#endif
+
 // CHECK-LABEL: define{{.*}} void @_Z22check_array_value_initv
 void check_array_value_init() {
   struct S;
@@ -46,7 +78,7 @@ void check_array_value_init() {
 
 // CHECK-LABEL: define{{.*}} void @_Z15string_nonconsti
 void string_nonconst(int n) {
-  // CHECK: icmp slt i{{32|64}} %{{[^ ]+}}, 4
+  // CHECK: icmp {{s|u}}lt i{{32|64}} %{{[^ ]+}}, 4
   // FIXME: Conditionally throw an exception rather than passing -1 to alloc function
   // CHECK: select
   // CHECK: %[[PTR:.*]] = call noalias noundef nonnull ptr @_Zna{{.}}(i{{32|64}}
@@ -57,6 +89,34 @@ void string_nonconst(int n) {
   new char[n] { "abc" };
 }
 
+#if __cplusplus >= 202002L
+// CHECKCXX20-LABEL: define{{.*}} void @_Z21string_nonconst_pareni
+void string_nonconst_paren(int n) {
+  // CHECKCXX20: icmp {{s|u}}lt i{{32|64}} %{{[^ ]+}}, 4
+  // FIXME: Conditionally throw an exception rather than passing -1 to alloc function
+  // CHECKCXX20: select
+  // CHECKCXX20: %[[PTR:.*]] = call noalias noundef nonnull ptr @_Zna{{.}}(i{{32|64}}
+  // CHECKCXX20: call void @llvm.memcpy{{.*}}(ptr align {{[0-9]+}} %[[PTR]], ptr align {{[0-9]+}} @[[ABC4]], i32 4,
+  // CHECKCXX20: %[[REST:.*]] = getelementptr inbounds i8, ptr %[[PTR]], i32 4
+  // CHECKCXX20: %[[RESTSIZE:.*]] = sub {{.*}}, 4
+  // CHECKCXX20: call void @llvm.memset{{.*}}(ptr align {{[0-9]+}} %[[REST]], i8 0, i{{32|64}} %[[RESTSIZE]],
+  new char[n]("abc");
+}
+
+// CHECKCXX20-LABEL: define{{.*}} void @_Z33string_nonconst_paren_extra_pareni
+void string_nonconst_paren_extra_paren(int n) {
+  // CHECKCXX20: icmp {{s|u}}lt i{{32|64}} %{{[^ ]+}}, 4
+  // FIXME: Conditionally throw an exception rather than passing -1 to alloc function
+  // CHECKCXX20: select
+  // CHECKCXX20: %[[PTR:.*]] = call noalias noundef nonnull ptr @_Zna{{.}}(i{{32|64}}
+  // CHECKCXX20: call void @llvm.memcpy{{.*}}(ptr align {{[0-9]+}} %[[PTR]], ptr align {{[0-9]+}} @[[ABC4]], i32 4,
+  // CHECKCXX20: %[[REST:.*]] = getelementptr inbounds i8, ptr %[[PTR]], i32 4
+  // CHECKCXX20: %[[RESTSIZE:.*]] = sub {{.*}}, 4
+  // CHECKCXX20: call void @llvm.memset{{.*}}(ptr align {{[0-9]+}} %[[REST]], i8 0, i{{32|64}} %[[RESTSIZE]],
+  new char[n](("abc"));
+}
+#endif
+
 // CHECK-LABEL: define{{.*}} void @_Z12string_exactv
 void string_exact() {
   // CHECK-NOT: icmp
@@ -66,6 +126,26 @@ void string_exact() {
   new char[4] { "abc" };
 }
 
+#if __cplusplus >= 202002L
+// CHECKCXX20-LABEL: define{{.*}} void @_Z18string_exact_parenv
+void string_exact_paren() {
+  // CHECKCXX20-NOT: icmp
+  // CHECKCXX20: %[[PTR:.*]] = call noalias noundef nonnull ptr @_Zna{{.}}(i{{32|64}} noundef 4)
+  // CHECKCXX20: call void @llvm.memcpy{{.*}}(ptr align {{[0-9]+}} %[[PTR]], ptr align {{[0-9]+}} @[[ABC4]], i32 4,
+  // CHECKCXX20-NOT: memset
+  new char[4]("abc");
+}
+
+// CHECKCXX20-LABEL: define{{.*}} void @_Z28string_exact_paren_extensionv
+void string_exact_paren_extension() {
+  // CHECKCXX20-NOT: icmp
+  // CHECKCXX20: %[[PTR:.*]] = call noalias noundef nonnull ptr @_Zna{{.}}(i{{32|64}} noundef 4)
+  // CHECKCXX20: call void @llvm.memcpy{{.*}}(ptr align {{[0-9]+}} %[[PTR]], ptr align {{[0-9]+}} @[[ABC4]], i32 4,
+  // CHECKCXX20-NOT: memset
+  new char[4](__extension__ "abc");
+}
+#endif
+
 // CHECK-LABEL: define{{.*}} void @_Z17string_sufficientv
 void string_sufficient() {
   // CHECK-NOT: icmp
@@ -76,6 +156,18 @@ void string_sufficient() {
   new char[15] { "abc" };
 }
 
+#if __cplusplus >= 202002L
+// CHECKCXX20-LABEL: define{{.*}} void @_Z23string_sufficient_parenv
+void string_sufficient_paren() {
+  // CHECKCXX20-NOT: icmp
+  // CHECKCXX20: %[[PTR:.*]] = call noalias noundef nonnull ptr @_Zna{{.}}(i{{32|64}} noundef 15)
+  // FIXME: For very large arrays, it would be preferable to emit a small copy and a memset.
+  // CHECKCXX20: call void @llvm.memcpy{{.*}}(ptr align {{[0-9]+}} %[[PTR]], ptr align {{[0-9]+}} @[[ABC15]], i32 15,
+  // CHECKCXX20-NOT: memset
+  new char[15] { "abc" };
+}
+#endif
+
 // CHECK-LABEL: define{{.*}} void @_Z10aggr_exactv
 void aggr_exact() {
   // CHECK-NOT: icmp