From 65037cffdb986acb08035988674765b6cf0f34e7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Sat, 29 Nov 2025 15:21:57 +0100
Subject: [PATCH] rustc, cargo-llvm-cov: enable profiler runtime on Darwin

Enable the LLVM profiler runtime on macOS by passing `--enable-profiler`
to rustc's configure. This allows cargo-llvm-cov and other coverage tools
to work on Darwin platforms.

The profiler is explicitly disabled for wasm and bpf targets which don't
support it.
---
 pkgs/by-name/ca/cargo-llvm-cov/package.nix | 3 +--
 pkgs/development/compilers/rust/rustc.nix  | 9 +++++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/pkgs/by-name/ca/cargo-llvm-cov/package.nix b/pkgs/by-name/ca/cargo-llvm-cov/package.nix
index 52db65a97405..4de52a2360c3 100644
--- a/pkgs/by-name/ca/cargo-llvm-cov/package.nix
+++ b/pkgs/by-name/ca/cargo-llvm-cov/package.nix
@@ -93,7 +93,6 @@ rustPlatform.buildRustPackage (finalAttrs: {
       CobaltCause
     ];
 
-    # The profiler runtime is (currently) disabled on non-Linux platforms
-    broken = !(stdenv.hostPlatform.isLinux && !stdenv.targetPlatform.isRedox);
+    broken = stdenv.targetPlatform.isRedox;
   };
 })
diff --git a/pkgs/development/compilers/rust/rustc.nix b/pkgs/development/compilers/rust/rustc.nix
index d2364f7aa533..b483594f7979 100644
--- a/pkgs/development/compilers/rust/rustc.nix
+++ b/pkgs/development/compilers/rust/rustc.nix
@@ -240,6 +240,15 @@ stdenv.mkDerivation (finalAttrs: {
     ++ optionals (stdenv.targetPlatform.isLinux && !(stdenv.targetPlatform.useLLVM or false)) [
       "--enable-profiler" # build libprofiler_builtins
     ]
+    ++ optionals stdenv.targetPlatform.isDarwin [
+      # potentially other llvm targets work with the same fix?
+      "--enable-profiler" # build libprofiler_builtins
+      # Disable profiler for targets that don't support it
+      "--set=target.wasm32-unknown-unknown.profiler=false"
+      "--set=target.wasm32v1-none.profiler=false"
+      "--set=target.bpfel-unknown-none.profiler=false"
+      "--set=target.bpfeb-unknown-none.profiler=false"
+    ]
     ++ optionals stdenv.buildPlatform.isMusl [
       "${setBuild}.musl-root=${pkgsBuildBuild.targetPackages.stdenv.cc.libc}"
     ]