Clean up overlays and remove obsolete dependencies

2026-09-19 22:42:44 -04:00
parent af4a917d92
commit a37b20979d
15 changed files with 435 additions and 149 deletions
@@ -0,0 +1,59 @@
+# Abseil BMI2 public header
+
+Vendored Abseil includes `bmi2intrin.h` directly when `__BMI2__` is enabled.
+Compilers reject that internal header without the umbrella-header setup.
+`bmi2-public-header.patch` includes `immintrin.h` instead, allowing builds
+that enable BMI2 through `-march=x86-64-v3`.
+
+## Scope and behavior
+
+The patch changes one include in
+`third_party/abseil-cpp/absl/container/internal/raw_hash_set.h`.
+`default.nix` applies it to Electron 43's unwrapped package, Deno's
+`librusty_v8`, and Signal's WebRTC dependency. It also supplies the patched
+Electron package to Signal. These overrides apply only to `x86-64-v3`.
+
+The shared file path is relative to each vendoring project's source root,
+not the root of a standalone Abseil checkout. No hash-table algorithm or
+test exclusion changes.
+
+## Reproduction and focused checks
+
+From this directory, check and apply the patch to each vendored source tree:
+
+```sh
+patch --dry-run --fuzz=0 -d /path/to/vendor-source -p1 < bmi2-public-header.patch
+patch --fuzz=0 -d /path/to/vendor-source -p1 < bmi2-public-header.patch
+```
+
+A small compiler check isolates the header requirement. With GCC or Clang
+on x86-64, compile `#include <bmi2intrin.h>` using `-march=x86-64-v3`; the
+compiler rejects the direct include. Changing it to `#include <immintrin.h>`
+should compile. The full consumer builds below check integration with their
+actual toolchains.
+
+## Upstream status
+
+Abseil addressed this issue through
+[PR #2071](https://github.com/abseil/abseil-cpp/pull/2071), imported by its
+upstream workflow. That change uses `x86gprintrin.h`; this local variant uses
+the public `immintrin.h` umbrella header for the vendored toolchains.
+Keep the workaround until all three bundled copies include a compatible fix.
+This file is a local adaptation, not a verbatim copy of the upstream diff.
+
+## Local NixOS integration and build results
+
+[`../default.nix`](../default.nix) merges this directory's overlay fragment
+because it repairs multiple packages. From the repository root, the consumer
+build commands are:
+
+```sh
+nix build --no-link -L .#nixosConfigurations.jeeves.pkgs.deno
+nix build --no-link -L .#nixosConfigurations.jeeves.pkgs.electron_43
+nix build --no-link -L .#nixosConfigurations.jeeves.pkgs.signal-desktop
+```
+
+The earlier extraction checked the vendored header snapshots and evaluated
+all three patch attachments. Those records do not establish successful full
+consumer rebuilds. No new compiler or consumer build was run for the layout
+change; the patch and override are unchanged.