From 788161457df73dcd3e43f56460be5d9d734fc92f Mon Sep 17 00:00:00 2001
From: Michael Daniels <mdaniels5757@gmail.com>
Date: Fri, 30 May 2025 21:31:00 -0400
Subject: [PATCH] llvm_{12,13,14,15}: fix build with Python 3.13

Python 3.13 removed the "pipes" module, which LLVM used through v16.

So we need a patch. It's only used once though!

A similar patch was used by Arch: https://gitlab.archlinux.org/archlinux/packaging/packages/llvm15/-/blob/main/nopipes.diff?ref_type=heads
---
 .../compilers/llvm/12/llvm/no-pipes.patch     | 19 ++++++++++++++++++
 .../compilers/llvm/common/llvm/default.nix    | 20 +++++++++----------
 .../compilers/llvm/common/patches.nix         |  6 ++++++
 3 files changed, 35 insertions(+), 10 deletions(-)
 create mode 100644 pkgs/development/compilers/llvm/12/llvm/no-pipes.patch

diff --git a/pkgs/development/compilers/llvm/12/llvm/no-pipes.patch b/pkgs/development/compilers/llvm/12/llvm/no-pipes.patch
new file mode 100644
index 000000000000..5b3d94e21ff6
--- /dev/null
+++ b/pkgs/development/compilers/llvm/12/llvm/no-pipes.patch
@@ -0,0 +1,19 @@
+diff --git a/test/Bindings/Go/lit.local.cfg b/test/Bindings/Go/lit.local.cfg
+index 91a0ad89..4da83a1a 100644
+--- a/test/Bindings/Go/lit.local.cfg
++++ b/test/Bindings/Go/lit.local.cfg
+@@ -1,5 +1,4 @@
+ import os
+-import pipes
+ import shlex
+ import sys
+ 
+@@ -56,7 +55,7 @@ def fixup_compiler_path(compiler):
+     except (AttributeError, OSError):
+         pass
+ 
+-    return ' '.join([pipes.quote(arg) for arg in args])
++    return ' '.join([shlex.quote(arg) for arg in args])
+ 
+ config.environment['CC'] = fixup_compiler_path(config.host_cc)
+ config.environment['CXX'] = fixup_compiler_path(config.host_cxx)
diff --git a/pkgs/development/compilers/llvm/common/llvm/default.nix b/pkgs/development/compilers/llvm/common/llvm/default.nix
index e7d12650fa47..6051243f6668 100644
--- a/pkgs/development/compilers/llvm/common/llvm/default.nix
+++ b/pkgs/development/compilers/llvm/common/llvm/default.nix
@@ -208,16 +208,16 @@ stdenv.mkDerivation (
               stripLen = 1;
             }
           )
-      ++
-        lib.optional (lib.versionOlder release_version "16")
-          # Fix musl build.
-          (
-            fetchpatch {
-              url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
-              relative = "llvm";
-              hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
-            }
-          )
+      ++ lib.optionals (lib.versionOlder release_version "16") [
+        # Fix musl build.
+        (fetchpatch {
+          url = "https://github.com/llvm/llvm-project/commit/5cd554303ead0f8891eee3cd6d25cb07f5a7bf67.patch";
+          relative = "llvm";
+          hash = "sha256-XPbvNJ45SzjMGlNUgt/IgEvM2dHQpDOe6woUJY+nUYA=";
+        })
+        # Fix for Python 3.13
+        (getVersionFile "llvm/no-pipes.patch")
+      ]
       ++ lib.optionals (lib.versionOlder release_version "14") [
         # Backport gcc-13 fixes with missing includes.
         (fetchpatch {
diff --git a/pkgs/development/compilers/llvm/common/patches.nix b/pkgs/development/compilers/llvm/common/patches.nix
index cc5872951c3b..cd4939dcd119 100644
--- a/pkgs/development/compilers/llvm/common/patches.nix
+++ b/pkgs/development/compilers/llvm/common/patches.nix
@@ -204,6 +204,12 @@
       path = ../12;
     }
   ];
+  "llvm/no-pipes.patch" = [
+    {
+      before = "16";
+      path = ../12;
+    }
+  ];
   "openmp/fix-find-tool.patch" = [
     {
       after = "17";