From d55298086a52f8f421646db5566289af888f255b Mon Sep 17 00:00:00 2001
From: Tristan Ross <tristan.ross@midstall.com>
Date: Sun, 22 Sep 2024 21:07:34 -0700
Subject: [PATCH] llvmPackages_git: 20.0.0-git-2024-09-16 ->
 20.0.0-git-2024-09-22

---
 .../compilers/llvm/common/clang/default.nix         |  7 +++++--
 pkgs/development/compilers/llvm/common/default.nix  | 13 ++++++++++++-
 pkgs/development/compilers/llvm/default.nix         |  6 +++---
 3 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/pkgs/development/compilers/llvm/common/clang/default.nix b/pkgs/development/compilers/llvm/common/clang/default.nix
index 9ef1a3a3c644be6..2b5aca109348599 100644
--- a/pkgs/development/compilers/llvm/common/clang/default.nix
+++ b/pkgs/development/compilers/llvm/common/clang/default.nix
@@ -72,7 +72,8 @@ let
       "-DCLANG_PSEUDO_GEN=${buildLlvmTools.libclang.dev}/bin/clang-pseudo-gen"
     ]) ++ lib.optionals (stdenv.targetPlatform.useLLVM or false) [
       "-DCLANG_DEFAULT_CXX_STDLIB=ON"
-    ] ++ devExtraCmakeFlags;
+    ] ++ lib.optional (lib.versionAtLeast release_version "20") "-DLLVM_DIR=${libllvm.dev}/lib/cmake/llvm"
+      ++ devExtraCmakeFlags;
 
     postPatch = ''
       # Make sure clang passes the correct location of libLTO to ld64
@@ -132,8 +133,10 @@ let
       mkdir -p $dev/bin
     '' + (if lib.versionOlder release_version "15" then ''
       cp bin/clang-tblgen $dev/bin
-    '' else ''
+    '' else if lib.versionOlder release_version "20" then ''
       cp bin/{clang-tblgen,clang-tidy-confusable-chars-gen,clang-pseudo-gen} $dev/bin
+    '' else ''
+      cp bin/{clang-tblgen,clang-tidy-confusable-chars-gen} $dev/bin
     '');
 
     passthru = {
diff --git a/pkgs/development/compilers/llvm/common/default.nix b/pkgs/development/compilers/llvm/common/default.nix
index 689ea9f7cb7b7ef..4f2580b1b984af6 100644
--- a/pkgs/development/compilers/llvm/common/default.nix
+++ b/pkgs/development/compilers/llvm/common/default.nix
@@ -483,7 +483,18 @@ let
               stripLen = 1;
               hash = "sha256-fqw5gTSEOGs3kAguR4tINFG7Xja1RAje+q67HJt2nGg=";
             })
-          ];
+          ]
+          ++
+            lib.optional (lib.versions.major metadata.release_version == "20")
+              # Fix for vt_gen, remove during next git bump
+              # https://github.com/llvm/llvm-project/pull/109817
+              (
+                fetchpatch {
+                  url = "https://github.com/llvm/llvm-project/commit/cace9869775a185793122f845d81a5ff46f15728.patch";
+                  stripLen = 1;
+                  hash = "sha256-lt1iQfNIc3ot1+6J7d7dbqULwT0MyLIwR2EZB7RfPp4=";
+                }
+              );
         pollyPatches =
           [ (metadata.getVersionFile "llvm/gnu-install-dirs-polly.patch") ]
           ++ lib.optional (lib.versionAtLeast metadata.release_version "15")
diff --git a/pkgs/development/compilers/llvm/default.nix b/pkgs/development/compilers/llvm/default.nix
index 2d0ffd4740f8963..9c27424a890ec34 100644
--- a/pkgs/development/compilers/llvm/default.nix
+++ b/pkgs/development/compilers/llvm/default.nix
@@ -30,9 +30,9 @@ let
     "18.1.8".officialRelease.sha256 = "sha256-iiZKMRo/WxJaBXct9GdAcAT3cz9d9pnAcO1mmR6oPNE=";
     "19.1.0-rc3".officialRelease.sha256 = "sha256-SRonSpXt1pH6Xk+rQZk9mrfMdvYIvOImwUfMUu3sBgs=";
     "20.0.0-git".gitRelease = {
-      rev = "48498ec7a4ded9f1bf813051abdc54c3e5b66fa7";
-      rev-version = "20.0.0-unstable-2024-09-16";
-      sha256 = "sha256-kybEr4T6vA4F9wtWdFf0QagVYU3tUvaXiSzPsxBkVUI=";
+      rev = "81c3499531c3fe03827bd8bc890e3a16db9e4c3c";
+      rev-version = "20.0.0-unstable-2024-09-22";
+      sha256 = "sha256-mQZhQ0qfWs4NmL62H3wNwG28iARUasWh9m8zMCNkRis=";
     };
   } // llvmVersions;