tree df06392ff9b0f45d6021a0c04fb24aea44784c18
parent f722b54efc2bce742ba882be310451639f31394a
author Tom Sepez <tsepez@chromium.org> 1684174536 +0000
committer Pdfium LUCI CQ <pdfium-scoped@luci-project-accounts.iam.gserviceaccount.com> 1684174536 +0000

Support BackupRefPtr in PDFium.

Uses BRP when PDFium is linked into a suitable embedder,

If PDFium is building against PartitionAlloc and PartitionAlloc is
building with either BRP or asan_use_unowned_ptr support, then make
PDFium's UnownedPtr<T> wrap raw_ptr<T>.

Otherwise, if we're building with ASAN, then use PDFium's built-in
dangling ptr detector.

Otherwise, use PDFium's built-in no-op UnownedPtr<> implementation.

These three cases all guarantee to null-initalize in the default
constructors, which PDFium requires. Combining PDFium's built-in
dangling ptr detector with PA's asan_use_unowned_ptr implementation
is left as a follow-up, as it requires a malloc-shim to get the
same functionality in a standalone build.

Bug: pdfium:2038
Change-Id: Ifb0220b63910cf8df903504ed5480bf98c973459
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/103500
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>