Skip to content

Reapply "[Clang][Sema] placement new initializes typedef array with correct size (#83124)" #89036

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 8 commits into from
Apr 23, 2024
Merged

Reapply "[Clang][Sema] placement new initializes typedef array with correct size (#83124)" #89036

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
56c2b4f
[Clang][Sema] placement new initializes typedef array with correct si…
mahtohappy Apr 16, 2024
bdd7f66
[Clang][Sema] placement new initializes typedef array with correct si…
mahtohappy Apr 16, 2024
71f00c3
Fix test from #83124 and #88902
erichkeane Apr 16, 2024
c64cd9d
[Clang][Sema] placement new initializes typedef array with correct size
mahtohappy Apr 17, 2024
1a73ca6
Reapply "[Clang][Sema] placement new initializes typedef array with c…
mahtohappy Apr 18, 2024
f95562d
Merge branch 'main' into temp_new
mahtohappy Apr 18, 2024
0f14d8f
Merge branch 'main' into temp_new
mahtohappy Apr 19, 2024
c9fbaf3
build trigger
mahtohappy Apr 21, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions clang/docs/ReleaseNotes.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -549,6 +549,7 @@ 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)

Bug Fixes to AST Handling
Expand Down
14 changes: 13 additions & 1 deletion clang/lib/Sema/TreeTransform.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -12910,6 +12910,19 @@ 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()) {
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

does Value dependence matter?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yes, it does. Both the original testcase from @slackito and simpler version of @dwblaikie are working now.
normal arrays with new initializer also were passing the check and their type was correct earlier so need for modification for them. typedef TYPE TArray[8]; TArray x; here type of array was Tarray which should be Type* so the check only for type dependent case.

Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Note I asked about VALUE dependence, not TYPE dependence. I see why type dependence would matter, but expressions can be both type and value dependent.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

No, it doesn't have value dependence.

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;
Expand Down Expand Up @@ -12971,7 +12984,6 @@ 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
Expand Down
2 changes: 1 addition & 1 deletion clang/lib/Serialization/ASTWriter.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5095,7 +5095,7 @@ 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;
Expand Down
32 changes: 32 additions & 0 deletions clang/test/SemaCXX/PR41441.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,32 @@
// RUN: %clang --target=x86_64-pc-linux -S -fno-discard-value-names -emit-llvm -o - %s | FileCheck %s

namespace std {
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Tests STILL haven't changed from the original patch. Please add the regression to this test as well.

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>();
}
Loading