Add Nix flake

.gitignore

@@ -11,3 +11,4 @@ bin
 *.exp
 *.pdb
 bake
+result

flake.nix

@@ -0,0 +1,144 @@
+{
+  description = "Bake - A build system and package manager for C/C++ projects";
+
+  # Key challenges solved in this flake:
+  # 1. Bake requires building not just the main binary, but also language drivers
+  # 2. Drivers must be built using bake itself (via `bake setup`)
+  # 3. Bake needs a writable BAKE_HOME for project metadata, conflicting with
+  #    Nix's read-only store
+  # 4. Solution: Initialize a writable ~/bake on first run, copied from the Nix store
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+
+        # Map Nix system to bake build directory
+        buildDirMap = {
+          "x86_64-linux" = "build-Linux";
+          "aarch64-linux" = "build-Linux";
+          "x86_64-darwin" = "build-Darwin";
+          "aarch64-darwin" = "build-Darwin";
+        };
+
+        buildDir = buildDirMap.${system} or (throw "Unsupported system: ${system}");
+
+      in {
+        packages = {
+          default = pkgs.stdenv.mkDerivation rec {
+            pname = "bake";
+            version = "2.5.0";
+
+            src = ./.;
+
+            nativeBuildInputs = [ pkgs.gnumake pkgs.makeWrapper ];
+
+            buildPhase = ''
+              runHook preBuild
+
+              # Build main bake binary first using make
+              make -C ${buildDir} clean all
+
+              # Use bake itself to build language drivers and utilities
+              # This is the proper way to build bake - drivers can't be built with
+              # make alone due to complex include path dependencies
+
+              # Set HOME to a temporary directory so bake installs to $HOME/bake
+              export HOME=$PWD/fake-home
+              mkdir -p $HOME
+
+              # Run bake setup with --local to:
+              # - Build bake.util (utility library)
+              # - Build bake.lang.c and bake.lang.cpp (language drivers)
+              # - Skip /usr/local/bin installation (--local flag)
+              ./bake setup --local
+
+              runHook postBuild
+            '';
+
+            installPhase = ''
+              runHook preInstall
+
+              mkdir -p $out/bin
+              mkdir -p $out/share/bake
+
+              # Copy the entire bake environment that was created by bake setup
+              # This includes: lib/, bin/, include/, meta/, templates/, etc.
+              # Use -L to dereference symlinks - bake setup creates symlinks back to
+              # the source directory, which would be dangling in the Nix store
+              cp -rL fake-home/bake/* $out/share/bake/
+
+              # Ensure the bake binary is present
+              if [ ! -f $out/share/bake/bin/bake ]; then
+                mkdir -p $out/share/bake/bin
+                cp bake $out/share/bake/bin/bake
+              fi
+
+              # Create a wrapper script that handles the read-only Nix store issue
+              # Problem: Bake needs BAKE_HOME to be writable (for project metadata),
+              #          but Nix store is read-only
+              # Solution: On first run, copy the Nix store bake environment to ~/bake
+              #           and use that as BAKE_HOME
+              cat > $out/bin/bake <<EOF
+              #!/bin/sh
+              # Initialize ~/bake if it doesn't exist
+              if [ ! -d "\$HOME/bake" ]; then
+                echo "Initializing bake environment in ~/bake..."
+                mkdir -p "\$HOME/bake"
+                # Copy the bake environment structure from Nix store
+                cp -r "$out/share/bake"/* "\$HOME/bake/"
+                # Make files writable (Nix store files are read-only by default)
+                chmod -R u+w "\$HOME/bake"
+                echo "Bake environment initialized."
+              fi
+              # Run bake with BAKE_HOME set to user's writable home directory
+              export BAKE_HOME="\$HOME/bake"
+              exec "$out/share/bake/bin/bake" "\$@"
+              EOF
+              chmod +x $out/bin/bake
+
+              runHook postInstall
+            '';
+
+            meta = with pkgs.lib; {
+              description = "A build system and package manager for C/C++ projects";
+              longDescription = ''
+                Bake is a build tool that makes building C/C++ code effortless.
+                It provides minimal, platform independent project configuration,
+                automatic dependency resolution, and builtin support for multiple
+                compilers including gcc, clang, msvc, and emscripten.
+              '';
+              homepage = "https://github.com/SanderMertens/bake";
+              license = licenses.gpl3Only;
+              maintainers = [ ];
+              platforms = platforms.unix;
+              mainProgram = "bake";
+            };
+          };
+        };
+
+        apps.default = {
+          type = "app";
+          program = "${self.packages.${system}.default}/bin/bake";
+        };
+
+        devShells.default = pkgs.mkShell {
+          buildInputs = with pkgs; [
+            gnumake
+            gcc
+            gdb
+          ];
+
+          shellHook = ''
+            echo "Bake development environment"
+            echo "Run 'make -C build-\$(uname) clean all' to build"
+          '';
+        };
+      }
+    );
+}