diff options
Diffstat (limited to 'cppu')
| -rw-r--r-- | cppu/source/uno/copy.hxx | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/cppu/source/uno/copy.hxx b/cppu/source/uno/copy.hxx index b0811b5fab10..b24e0e337bf5 100644 --- a/cppu/source/uno/copy.hxx +++ b/cppu/source/uno/copy.hxx @@ -22,7 +22,9 @@ #include "prim.hxx" #include "constr.hxx" #include <cassert> +#include <cstddef> #include <cstdlib> +#include <type_traits> namespace cppu { @@ -30,6 +32,22 @@ namespace cppu //#### copy construction ########################################################################### +namespace { + +// The non-dynamic prefix of sal_Sequence (aka uno_Sequence): +struct SequencePrefix { + sal_Int32 nRefCount; + sal_Int32 nElements; +}; +static_assert(sizeof (SequencePrefix) < sizeof (uno_Sequence)); +static_assert(offsetof(SequencePrefix, nRefCount) == offsetof(uno_Sequence, nRefCount)); +static_assert( + std::is_same_v<decltype(SequencePrefix::nRefCount), decltype(uno_Sequence::nRefCount)>); +static_assert(offsetof(SequencePrefix, nElements) == offsetof(uno_Sequence, nElements)); +static_assert( + std::is_same_v<decltype(SequencePrefix::nElements), decltype(uno_Sequence::nElements)>); + +} inline uno_Sequence * allocSeq( sal_Int32 nElementSize, sal_Int32 nElements ) @@ -42,9 +60,11 @@ inline uno_Sequence * allocSeq( pSeq = static_cast<uno_Sequence *>(std::malloc( nSize )); if (pSeq != nullptr) { - // header init - pSeq->nRefCount = 1; - pSeq->nElements = nElements; + // header init, going via SequencePrefix to avoid UBSan insufficient-object-size + // warnings when `nElements == 0` and thus `nSize < sizeof (uno_Sequence)`: + auto const header = reinterpret_cast<SequencePrefix *>(pSeq); + header->nRefCount = 1; + header->nElements = nElements; } } return pSeq; |