rsmith added inline comments.
================ Comment at: clang/lib/Sema/SemaDecl.cpp:14361 +/// attributes are applied to declarations. +void Sema::AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction( + FunctionDecl *FD) { ---------------- This should all be done by CodeGen, not by injecting source-level attributes. ================ Comment at: clang/lib/Sema/SemaDecl.cpp:14414-14432 + // C++2a [basic.stc.dynamic.allocation]p3: + // For an allocation function [...], the pointer returned on a successful + // call shall represent the address of storage that is aligned as follows: + // (3.2),(3.3) Otherwise, [...] the storage is aligned for any object + // that does not have new-extended alignment [...]. + // + // NOTE: we intentionally always manifest this basic alignment, because it is ---------------- This is incorrect. The pointer returned by `operator new` is only suitably aligned for any object that does not have new-extended alignment **and is of the requested size**. And the pointer returned by `operator new[]` is suitably aligned for any object **that is no larger than the requested size**. (These are both different from the rule for `malloc`, which does behave as you're suggesting here.) For example: Suppose the default new alignment and the largest fundamental alignment are both 16, and we try to allocate 12 bytes. Then: * `operator new` need only return storage that is 4-byte aligned (because that is the largest alignment that can be required by a type `T` with `sizeof(T) == 12`) * `operator new` need only return storage that is 8-byte aligned (because that is the largest alignment that can be required by a type `T` with `sizeof(T) <= 12`) * `malloc` must return storage that is 16-byte aligned (because that is the largest fundamental alignment) Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D73380/new/ https://reviews.llvm.org/D73380 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits