Revert "Remove mavenix + unused old nix infrastructure" (#928)

Reverts #923 closes #926

default.nix

@@ -0,0 +1,68 @@
+let
+  sources = import ./nix/sources.nix;
+  pinned = import sources."nixpkgs" {
+    config = { };
+    overlays = [ ];
+  };
+
+in { pkgs ? pinned
+
+  # Override `src` when this project is imported as a Git submodule:
+  #
+  # > ttuegel.cleanGitSubtree {
+  # >   name = "llvm-backend";
+  # >   src = ./parent/repo;
+  # >   subDir = "path/to/submodule";
+  # > };
+  #
+  # Use `cleanGitSubtree` whenever possible to preserve the same source code
+  # layout as the runtimeverification/llvm-backend repository (to enable cache re-use).
+  #
+, src ? null
+
+  # Build an optimized release package.
+  # Currently requires dependents to use LTO. Use sparingly.
+, cmakeBuildType ? "FastBuild" }:
+
+let
+  localOverlay = import ./nix/overlay.nix;
+
+  localPkgs = import sources."nixpkgs" {
+    config = { };
+    overlays = [
+      (final: prev:
+        let
+          ttuegel = import sources."ttuegel" { inherit (prev) pkgs; };
+          # Avoid spurious rebuilds by ignoring files that don't affect the build.
+          mavenix = import sources."mavenix" { inherit (prev) pkgs; };
+        in {
+          llvm-version = 15;
+          llvm-backend-build-type = cmakeBuildType;
+          inherit (mavenix) buildMaven;
+          mavenix-cli = mavenix.cli;
+
+          llvm-backend-src = ttuegel.orElse src (ttuegel.cleanSourceWith {
+            name = "llvm-backend-src";
+            src = ./.;
+            ignore = [ "/nix" "*.nix" "*.nix.sh" "/.github" ];
+          });
+
+          llvm-backend-matching-src = ttuegel.cleanSourceWith {
+            name = "llvm-backend-matching-src";
+            src = ttuegel.orElse src (ttuegel.cleanGitSubtree {
+              name = "llvm-backend-src";
+              src = ./.;
+            });
+            subDir = "matching";
+          };
+
+        })
+      localOverlay
+    ];
+  };
+in {
+  inherit (localPkgs) llvm-backend llvm-backend-matching integration-tests;
+  inherit (localPkgs) clang; # for compatibility
+  inherit (localPkgs) mavenix-cli; # for CI
+}
+

flake.nix

@@ -16,15 +16,16 @@
     pybind11-src.url =
       "github:pybind/pybind11/0ba639d6177659c5dc2955ac06ad7b5b0d22e05c";
     pybind11-src.flake = false;
+    mavenix.url = "github:nix-community/mavenix";
   };
 
-  outputs = { self, nixpkgs, utils, fmt-src, immer-src, rapidjson-src, pybind11-src }:
+  outputs = { self, nixpkgs, utils, fmt-src, immer-src, rapidjson-src, pybind11-src, mavenix }:
     let
       inherit (nixpkgs) lib;
 
-      # put required packages into local overlay
+      # put devShell and any other required packages into local overlay
       # if you have additional overlays, you may add them here
-      localOverlay = import ./nix/overlay.nix;
+      localOverlay = import ./nix/overlay.nix; # this should expose devShell
       depsOverlay = (final: prev: {
         inherit fmt-src immer-src rapidjson-src pybind11-src;
 
@@ -70,10 +71,6 @@
           ] ./matching);
       });
 
-      maven-overlay = (final: prev: {
-        maven = prev.callPackage ./nix/maven.nix { };
-      });
-
       llvm-backend-overlay =
         nixpkgs.lib.composeManyExtensions [ depsOverlay localOverlay ];
 
@@ -84,7 +81,7 @@
               inherit llvm-version;
               inherit llvm-backend-build-type;
             })
-            maven-overlay
+            mavenix.overlay
             llvm-backend-overlay
           ];
           inherit system;
@@ -108,7 +105,7 @@
             {
               name = "llvm-backend-${toString args.llvm-version}-${args.build-type}";
               value = {
-                inherit (pkgs) llvm-backend llvm-backend-matching llvm-kompile-testing integration-tests;
+                inherit (pkgs) llvm-backend llvm-backend-matching llvm-kompile-testing integration-tests devShell;
               };
             }
         ));
@@ -127,9 +124,9 @@
           llvm-backend-15-FastBuild.integration-tests
           llvm-backend-16-FastBuild.integration-tests
         ];
+        devShells.default = llvm-backend-16-FastBuild.devShell;
       }) // {
         # non-system suffixed items should go here
         overlays.default = llvm-backend-overlay;
-        overlays.maven = maven-overlay;
       };
 }

nix/devShell.nix

@@ -0,0 +1,7 @@
+{ mkShell, llvm-backend, llvm-backend-matching, mavenix-cli }:
+
+mkShell {
+  inputsFrom = [ llvm-backend llvm-backend-matching ];
+
+  nativeBuildInputs = [ mavenix-cli ];
+}