diff options
| -rw-r--r-- | src/corelib/text/qbytearray.cpp | 9 | ||||
| -rw-r--r-- | src/corelib/text/qstring.cpp | 9 | ||||
| -rw-r--r-- | src/corelib/tools/qarraydata.cpp | 9 | ||||
| -rw-r--r-- | src/corelib/tools/qarraydataops.h | 2 |
4 files changed, 16 insertions, 13 deletions
diff --git a/src/corelib/text/qbytearray.cpp b/src/corelib/text/qbytearray.cpp index 14789c8a2c..bc2f73a67d 100644 --- a/src/corelib/text/qbytearray.cpp +++ b/src/corelib/text/qbytearray.cpp @@ -1708,12 +1708,11 @@ void QByteArray::reallocData(qsizetype alloc, QArrayData::AllocationOption optio return; } - // there's a case of slow reallocate path where we need to memmove the data - // before a call to ::realloc(), meaning that there's an extra "heavy" - // operation. just prefer ::malloc() branch in this case - const bool slowReallocatePath = d.freeSpaceAtBegin() > 0; + // don't use reallocate path when reducing capacity and there's free space + // at the beginning: might shift data pointer outside of allocated space + const bool cannotUseReallocate = d.freeSpaceAtBegin() > 0; - if (d->needsDetach() || slowReallocatePath) { + if (d->needsDetach() || cannotUseReallocate) { DataPointer dd(Data::allocate(alloc, option), qMin(alloc, d.size)); if (dd.size > 0) ::memcpy(dd.data(), d.data(), dd.size); diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp index 76b25427bd..1447b5b21c 100644 --- a/src/corelib/text/qstring.cpp +++ b/src/corelib/text/qstring.cpp @@ -2504,12 +2504,11 @@ void QString::reallocData(qsizetype alloc, QArrayData::AllocationOption option) return; } - // there's a case of slow reallocate path where we need to memmove the data - // before a call to ::realloc(), meaning that there's an extra "heavy" - // operation. just prefer ::malloc() branch in this case - const bool slowReallocatePath = d.freeSpaceAtBegin() > 0; + // don't use reallocate path when reducing capacity and there's free space + // at the beginning: might shift data pointer outside of allocated space + const bool cannotUseReallocate = d.freeSpaceAtBegin() > 0; - if (d->needsDetach() || slowReallocatePath) { + if (d->needsDetach() || cannotUseReallocate) { DataPointer dd(Data::allocate(alloc, option), qMin(alloc, d.size)); if (dd.size > 0) ::memcpy(dd.data(), d.data(), dd.size * sizeof(QChar)); diff --git a/src/corelib/tools/qarraydata.cpp b/src/corelib/tools/qarraydata.cpp index 2bf3e9bacc..5feb1ac8f6 100644 --- a/src/corelib/tools/qarraydata.cpp +++ b/src/corelib/tools/qarraydata.cpp @@ -233,10 +233,13 @@ QArrayData::reallocateUnaligned(QArrayData *data, void *dataPointer, { Q_ASSERT(!data || !data->isShared()); - qsizetype headerSize = sizeof(QArrayData); + const qsizetype headerSize = sizeof(QArrayData); qsizetype allocSize = calculateBlockSize(capacity, objectSize, headerSize, option); - qptrdiff offset = dataPointer ? reinterpret_cast<char *>(dataPointer) - reinterpret_cast<char *>(data) : headerSize; + const qptrdiff offset = dataPointer + ? reinterpret_cast<char *>(dataPointer) - reinterpret_cast<char *>(data) + : headerSize; Q_ASSERT(offset > 0); + Q_ASSERT(offset <= allocSize); // equals when all free space is at the beginning allocSize = reserveExtraBytes(allocSize); if (Q_UNLIKELY(allocSize < 0)) // handle overflow. cannot reallocate reliably @@ -244,7 +247,7 @@ QArrayData::reallocateUnaligned(QArrayData *data, void *dataPointer, QArrayData *header = static_cast<QArrayData *>(::realloc(data, size_t(allocSize))); if (header) { - header->alloc = uint(capacity); + header->alloc = capacity; dataPointer = reinterpret_cast<char *>(header) + offset; } else { dataPointer = nullptr; diff --git a/src/corelib/tools/qarraydataops.h b/src/corelib/tools/qarraydataops.h index c6ab3b1c48..d7e7b4bf07 100644 --- a/src/corelib/tools/qarraydataops.h +++ b/src/corelib/tools/qarraydataops.h @@ -479,6 +479,7 @@ public: void reallocate(qsizetype alloc, QArrayData::AllocationOption option) { auto pair = Data::reallocateUnaligned(this->d, this->ptr, alloc, option); + Q_ASSERT(pair.first != nullptr); this->d = pair.first; this->ptr = pair.second; } @@ -1132,6 +1133,7 @@ public: void reallocate(qsizetype alloc, QArrayData::AllocationOption option) { auto pair = Data::reallocateUnaligned(this->d, this->ptr, alloc, option); + Q_ASSERT(pair.first != nullptr); this->d = pair.first; this->ptr = pair.second; } |