moved rhapsody-in-green off v3

2026-09-22 19:20:50 -04:00
parent 24af88be1d
commit 7541387d7c
34 changed files with 27 additions and 25 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.
@@ -0,0 +1,20 @@
+Subject: [PATCH] abseil: include BMI2 intrinsics through the public header
+
+GCC and Clang reject direct inclusion of bmi2intrin.h. Include immintrin.h
+instead so that the compiler supplies the required intrinsic setup when
+BMI2 is enabled, including builds targeting x86-64-v3.
+
+This patch is shared by the vendored Abseil copies in Electron, rusty_v8
+(Deno), and Signal's WebRTC build.
+
+--- a/third_party/abseil-cpp/absl/container/internal/raw_hash_set.h
+++ b/third_party/abseil-cpp/absl/container/internal/raw_hash_set.h
+@@ -226,7 +226,7 @@
+ #endif
+ 
+ #ifdef __BMI2__
+-#include <bmi2intrin.h>
+#include <immintrin.h>
+ #endif  // __BMI2__
+ 
+ namespace absl {
@@ -0,0 +1,38 @@
+# Abseil accepted the upstream fix: https://github.com/abseil/abseil-cpp/pull/2071
+# Keep this workaround until Electron, Deno's rusty_v8, and Signal's WebRTC
+# update their bundled Abseil copies to include it.
+{ prev }:
+let
+  patchAbseilBmi2Include =
+    package:
+    package.overrideAttrs (old: {
+      # GCC and Clang require the public umbrella header for BMI2 intrinsics.
+      patches = (old.patches or [ ]) ++ [ ./bmi2-public-header.patch ];
+    });
+
+  electron43Unwrapped = patchAbseilBmi2Include prev.electron_43.unwrapped;
+  electron43 = prev.electron_43.override {
+    electron-unwrapped = electron43Unwrapped;
+  };
+
+  signalCallPackage =
+    path: args:
+    let
+      package = prev.callPackage path args;
+    in
+    if builtins.baseNameOf path == "webrtc.nix" then patchAbseilBmi2Include package else package;
+in
+prev.lib.optionalAttrs ((prev.stdenv.hostPlatform.gcc.arch or null) == "x86-64-v3") {
+  deno =
+    let
+      librusty_v8 = patchAbseilBmi2Include prev.deno.passthru.librusty_v8;
+    in
+    prev.deno.override { inherit librusty_v8; };
+
+  electron_43 = electron43;
+
+  signal-desktop = prev.signal-desktop.override {
+    electron_43 = electron43;
+    callPackage = signalCallPackage;
+  };
+}