diff options
author | mahtohappy <Happy.Kumar@Windriver.com> | 2024-04-16 17:48:45 +0530 |
---|---|---|
committer | GitHub <noreply@github.com> | 2024-04-16 14:18:45 +0200 |
commit | c309dc6d0759b23b570c563f611530ff1a49e1bd (patch) | |
tree | d16c6d4e854bec4f03e650fbbee96d30d9a84f22 | |
parent | d4602a96b48b00a50c4d891673fc622ca2e37f0a (diff) |
[Clang][Sema] placement new initializes typedef array with correct size (#83124)
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 #41441
-rw-r--r-- | clang/docs/ReleaseNotes.rst | 2 | ||||
-rw-r--r-- | clang/lib/Sema/TreeTransform.h | 14 | ||||
-rw-r--r-- | clang/test/SemaCXX/instantiate-new-placement-size.cpp | 20 |
3 files changed, 35 insertions, 1 deletions
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 76701dc723b6..255d2cc04404 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -539,6 +539,8 @@ Bug Fixes to C++ Support Fixes (#GH70604), (#GH79754), (#GH84163), (#GH84425), (#GH86054), (#GH86398), and (#GH86399). - Fix a crash when deducing ``auto`` from an invalid dereference (#GH88329). - Fix a crash in requires expression with templated base class member function. Fixes (#GH84020). +- placement new initializes typedef array with correct size + (`#GH41441 <https://github.com/llvm/llvm-project/issues/41441>`_) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h index 8c96134af7c8..9d15f3eacbb0 100644 --- a/clang/lib/Sema/TreeTransform.h +++ b/clang/lib/Sema/TreeTransform.h @@ -12802,6 +12802,19 @@ 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) { + 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; @@ -12863,7 +12876,6 @@ 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/test/SemaCXX/instantiate-new-placement-size.cpp b/clang/test/SemaCXX/instantiate-new-placement-size.cpp new file mode 100644 index 000000000000..7a29d3dee849 --- /dev/null +++ b/clang/test/SemaCXX/instantiate-new-placement-size.cpp @@ -0,0 +1,20 @@ +// RUN: %clang -S -fno-discard-value-names -emit-llvm -o - %s | FileCheck %s +// Issue no: 41441 +#include <new> + +// 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(); +} + +int main() +{ + f<char>(); + f<int>(); +} |