diff options
author | mahtohappy <Happy.Kumar@Windriver.com> | 2024-04-23 20:07:07 +0530 |
---|---|---|
committer | GitHub <noreply@github.com> | 2024-04-23 07:37:07 -0700 |
commit | 74cab546825b32f24e44d69942cdbdd129160471 (patch) | |
tree | 02b9a20b1da606dcdfb86c381a9a8662589c8763 | |
parent | 282ab543a92740100c1119c701258c2900c5d00c (diff) |
Reapply "[Clang][Sema] placement new initializes typedef array with correct size (#83124)" (#89036)
When in-place new-ing a local variable of an array of trivial type, the
generated code calls 'memset' with the correct size of the array,
earlier it was generating size (squared of the typedef array + size).
The cause: typedef TYPE TArray[8]; TArray x; The type of declarator is
Tarray[8] and in SemaExprCXX.cpp::BuildCXXNew we check if it's of
typedef and of constant size then we get the original type and it works
fine for non-dependent cases.
But in case of template we do TreeTransform.h:TransformCXXNEWExpr and
there we again check the allocated type which is TArray[8] and it stays
that way, so ArraySize=(Tarray[8] type, alloc Tarray[8*type]) so the
squared size allocation.
ArraySize gets calculated earlier in TreeTransform.h so that
if(!ArraySize) condition was failing.
fix: I changed that condition to if(ArraySize).
fixes https://github.com/llvm/llvm-project/issues/41441
---------
Co-authored-by: erichkeane <ekeane@nvidia.com>
-rw-r--r-- | clang/docs/ReleaseNotes.rst | 1 | ||||
-rw-r--r-- | clang/lib/Sema/TreeTransform.h | 14 | ||||
-rw-r--r-- | clang/lib/Serialization/ASTWriter.cpp | 2 | ||||
-rw-r--r-- | clang/test/SemaCXX/PR41441.cpp | 32 |
4 files changed, 47 insertions, 2 deletions
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 3db558a1c11a..d1f7293a842b 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -557,6 +557,7 @@ Bug Fixes to C++ Support - Fix a crash in requires expression with templated base class member function. Fixes (#GH84020). - Fix a crash caused by defined struct in a type alias template when the structure has fields with dependent type. Fixes (#GH75221). +- Fix placement new initializes typedef array with correct size. Fixes (#GH41441). - Fix the Itanium mangling of lambdas defined in a member of a local class (#GH88906) - Fixed a crash when trying to evaluate a user-defined ``static_assert`` message whose ``size()`` function returns a large or negative value. Fixes (#GH89407). diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h index 9404be5a46f3..539a18eb92a7 100644 --- a/clang/lib/Sema/TreeTransform.h +++ b/clang/lib/Sema/TreeTransform.h @@ -12943,6 +12943,19 @@ TreeTransform<Derived>::TransformCXXNewExpr(CXXNewExpr *E) { ArraySize = NewArraySize.get(); } + // Per C++0x [expr.new]p5, the type being constructed may be a + // typedef of an array type. + QualType AllocType = AllocTypeInfo->getType(); + if (ArraySize && E->isTypeDependent()) { + if (const ConstantArrayType *Array = + SemaRef.Context.getAsConstantArrayType(AllocType)) { + ArraySize = IntegerLiteral::Create(SemaRef.Context, Array->getSize(), + SemaRef.Context.getSizeType(), + E->getBeginLoc()); + AllocType = Array->getElementType(); + } + } + // Transform the placement arguments (if any). bool ArgumentChanged = false; SmallVector<Expr*, 8> PlacementArgs; @@ -13004,7 +13017,6 @@ TreeTransform<Derived>::TransformCXXNewExpr(CXXNewExpr *E) { return E; } - QualType AllocType = AllocTypeInfo->getType(); if (!ArraySize) { // If no array size was specified, but the new expression was // instantiated with an array type (e.g., "new T" where T is diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp index a1b340b252fb..21cf72ab0f91 100644 --- a/clang/lib/Serialization/ASTWriter.cpp +++ b/clang/lib/Serialization/ASTWriter.cpp @@ -5097,7 +5097,7 @@ void ASTWriter::WriteSpecialDeclRecords(Sema &SemaRef) { DeclsToCheckForDeferredDiags.push_back(getDeclID(D)); if (!DeclsToCheckForDeferredDiags.empty()) Stream.EmitRecord(DECLS_TO_CHECK_FOR_DEFERRED_DIAGS, - DeclsToCheckForDeferredDiags); + DeclsToCheckForDeferredDiags); // Write the record containing CUDA-specific declaration references. RecordData CUDASpecialDeclRefs; diff --git a/clang/test/SemaCXX/PR41441.cpp b/clang/test/SemaCXX/PR41441.cpp new file mode 100644 index 000000000000..3f60b6e20920 --- /dev/null +++ b/clang/test/SemaCXX/PR41441.cpp @@ -0,0 +1,32 @@ +// RUN: %clang --target=x86_64-pc-linux -S -fno-discard-value-names -emit-llvm -o - %s | FileCheck %s + +namespace std { + using size_t = decltype(sizeof(int)); +}; +void* operator new[](std::size_t, void*) noexcept; + +// CHECK: call void @llvm.memset.p0.i64(ptr align 1 %x, i8 0, i64 8, i1 false) +// CHECK: call void @llvm.memset.p0.i64(ptr align 16 %x, i8 0, i64 32, i1 false) +template <typename TYPE> +void f() +{ + typedef TYPE TArray[8]; + + TArray x; + new(&x) TArray(); +} + +template <typename T> +void f1() { + int (*x)[1] = new int[1][1]; +} +template void f1<char>(); +void f2() { + int (*x)[1] = new int[1][1]; +} + +int main() +{ + f<char>(); + f<int>(); +} |