Reland "Roll libc++ from def01bd012f5 to d816ed0274ed (1 revision)" This is a reland of commit c0c2d1ddc08c641e430e336a35d780e819147161 The roll broke the linux-cast-x64-rel bot. This reland modifies `chromecast/browser/devtools/cast_ui_devtools.cc` to move the dom_agent_views object first, so that it is destructed in the correct order. Original change's description: > Roll libc++ from def01bd012f5 to d816ed0274ed (1 revision) > > https://chromium.googlesource.com/external/github.com/llvm/llvm-project/libcxx.git/+log/def01bd012f5..d816ed0274ed > > 2026-08-25 nikolasklauser@berlin.de [libc++][NFC] Remove vector::__base_destruct_at_end (#217631) > > Updates tests and production destructors that relied on `std::vector` > destroying elements in reverse (back-to-front) order after > `std::vector::__destruct_at_end` switched to `std::destroy` > (front-to-back) in #21763 > > If this roll has caused a breakage, revert this CL and stop the roller > using the controls here: > https://autoroll.skia.org/r/libcxx-chromium > Please CC hans@chromium.org,thakis@chromium.org on the revert to ensure that a human > is aware of the problem. > > To file a bug in Chromium: https://bugs.chromium.org/p/chromium/issues/entry > > To report a problem with the AutoRoller itself, please file a bug: > https://issues.skia.org/issues/new?component=1389291&template=1850622 > > Documentation for the AutoRoller is here: > https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md > > Bug: 503250165 > Change-Id: I3e910d914a067c3fcf1a82446347474ebdd55479 > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8710758 > Reviewed-by: Colin Blundell <blundell@chromium.org> > Reviewed-by: Bo Liu <boliu@chromium.org> > Commit-Queue: Liza Burakova <liza@chromium.org> > Reviewed-by: Jan Keitel <jkeitel@google.com> > Reviewed-by: Nico Weber <thakis@chromium.org> > Reviewed-by: Francois Pierre Doray <fdoray@chromium.org> > Reviewed-by: Mikhail Khokhlov <khokhlov@google.com> > Cr-Commit-Position: refs/heads/main@{#1736630} Bug: 503250165 Change-Id: I4084600803ea0ef3d03579a01b4520ee17ae8066 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8777268 Owners-Override: Colin Blundell <blundell@chromium.org> Reviewed-by: Mikhail Khokhlov <khokhlov@google.com> Reviewed-by: Colin Blundell <blundell@chromium.org> Reviewed-by: Jan Keitel <jkeitel@google.com> Commit-Queue: Liza Burakova <liza@chromium.org> Reviewed-by: Nico Weber <thakis@chromium.org> Reviewed-by: Francois Pierre Doray <fdoray@chromium.org> Reviewed-by: Ryan Sultanem <rsult@google.com> Cr-Commit-Position: refs/heads/main@{#1740555} NOKEYCHECK=True GitOrigin-RevId: 9bdf20b5fe1793a71845c804a7447f31c26d780b
Contains a written down set of principles and other information on //base. Please add to it!
Chromium is a very mature project. Most things that are generally useful are already here and things not here aren't generally useful.
The bar for adding stuff to base is that it must have demonstrated wide applicability. Prefer to add things closer to where they're used (i.e. “not base”), and pull into base only when needed. In a project our size, sometimes even duplication is OK and inevitable.
Adding a new logging macro DPVELOG_NE is not more clear than just writing the stuff you want to log in a regular logging statement, even if it makes your calling code longer. Just add it to your own code.
If the code in question does not need to be used inside base, but will have multiple consumers across the codebase, consider placing it in a new directory under components/ instead.
base is written for the Chromium project and is not intended to be used outside it. Using base outside of src.git is explicitly not supported, and base makes no guarantees about API (or even ABI) stability (like all other code in Chromium). New code that depends on base/ must be in src.git. Code that's not in src.git but pulled in through DEPS (for example, v8) cannot use base.
Owners are added when a contributor has shown the above qualifications and when they express interest. There isn't an upper bound on the number of OWNERS.
Since the primitives provided by //base are used very widely, it is important to ensure they scale to the necessary workloads and perform well under all supported platforms. The base_perftests target is a suite of synthetic microbenchmarks that measure performance in various scenarios:
thread_local, the implementation in //base, the POSIX/WinAPI directly)Regressions in these benchmarks can generally by caused by 1) operating system changes, 2) compiler version or flag changes or 3) changes in //base code itself.
Rust code in base should be organized into very small crates, split up by function. Merging crates is sometimes unavoidable (due to dependency cycles or the orphaning rule).
Rust files should live near the equivalent C++ files (if any), and use the same naming scheme (for example, run_loop.rs, not run_loop_rust.rs).
When adding FFI shims, prefer separate _shim.h files rather than adding code to existing C++ files. This helps avoid circular dependencies with the //base target. It also avoids adding code to commonly-used headers, which can increase compile size by a lot.
Crates which you expect to be widely used should be added to the public_deps of the //base:base_rust target, so that developers can simply depend on //base:base_rust the same way they do with //base.