[nix] switch to xsfmm llvm

Signed-off-by: unlsycn <[email protected]>

Author: unlsycn

.scalafmt.conf

@@ -1,4 +1,4 @@
-version = "3.9.2"
+version = "3.9.4"
 
 maxColumn = 120
 align.preset = most

flake.lock

@@ -4,6 +4,7 @@
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
     flake-parts.url = "github:hercules-ci/flake-parts";
+    nixpkgs-for-llvm.url = "github:NixOS/nixpkgs/nixos-unstable-small";
     mill-ivy-fetcher.url = "github:Avimitin/mill-ivy-fetcher";
     circt-follow.url = "github:sequencer/zaozi";
     treefmt-nix.url = "github:numtide/treefmt-nix";
@@ -13,6 +14,7 @@
     inputs@{
       self,
       nixpkgs,
+      nixpkgs-for-llvm,
       mill-ivy-fetcher,
       circt-follow,
       ...
@@ -51,6 +53,10 @@
               mill-ivy-fetcher.overlays.default
               # Follow CIRCT from sequencer/zaozi overlay
               circt-follow.overlays.default
+              # pin riscv32 packages to avoid consistent breakage
+              (final: prev: {
+                rv32_nixpkgs = nixpkgs-for-llvm.legacyPackages."${system}".pkgsCross.riscv32-embedded;
+              })
               overlay
             ];
           };

flake.nix

@@ -1,13 +1,11 @@
 final: prev:
 
 let
-  llvmForRVV_attrName = "llvmPackages_19";
-  rv32_pkgs = final.pkgsCross.riscv32-embedded;
-  rv32_buildPkgs = rv32_pkgs.buildPackages;
+  llvmForRVV_attrName = "llvmPackages_git";
+  rv32_pkgs = final.rv32_nixpkgs;
+  rv32_buildPkgs = final.rv32_nixpkgs.buildPackages;
 in
 rec {
-  inherit rv32_pkgs rv32_buildPkgs; # for easier inspection
-
   getEnv' =
     key:
     let
@@ -92,9 +90,31 @@ rec {
         newlib = rv32_pkgs.stdenv.cc.libc.overrideAttrs (oldAttrs: {
           CFLAGS_FOR_TARGET = "-march=rv32imacf_zvl128b_zve32f -mabi=ilp32f";
         });
+
+        llvmPackages = rv32_buildPkgs.${llvmForRVV_attrName};
+        patchedCC =
+          let
+            llvmSrc = prev.fetchFromGitHub {
+              owner = "topperc";
+              repo = "llvm-project";
+              rev = "bb123ff9401b517d877de4ed6fd9ea61edf49dbb";
+              hash = "sha256-6ca5FhSsG5Qik7wi6Vn3OmUmKR/hULSDniu4JLo+5jM=";
+            };
+            vscalePatch = prev.fetchpatch {
+              url = "https://github.com/llvm/llvm-project/pull/140195.patch";
+              hash = "sha256-fevg7xQ/9RuOvGnT9uBhBAoM0wq+hB0tvidsg2LkxG8=";
+              stripLen = 1;
+            };
+          in
+          llvmPackages.clang-unwrapped.override {
+            monorepoSrc = llvmSrc;
+            libllvm = (llvmPackages.libllvm.override { monorepoSrc = llvmSrc; }).overrideAttrs (old: {
+              patches = old.patches ++ [ vscalePatch ];
+            });
+          };
       in
       rv32_buildPkgs.wrapCCWith rec {
-        cc = rv32_buildPkgs.${llvmForRVV_attrName}.clang-unwrapped;
+        cc = patchedCC;
         libc = newlib;
         bintools = rv32_pkgs.stdenv.cc.bintools.override {
           inherit libc; # we must keep consistency of bintools libc and compiler libc