Several nix fixes (#1737)

* Fixed nix c3c development shell

* Fix unknown git hash on nix build

flake.nix

@@ -8,12 +8,17 @@
 
   outputs = { self, ... } @ inputs: inputs.flake-utils.lib.eachDefaultSystem 
   (system: 
-    let pkgs = import inputs.nixpkgs { inherit system; }; in 
-    {
+    let pkgs = import inputs.nixpkgs { inherit system; }; 
+        call = set: pkgs.callPackage ./nix/default.nix ( 
+          set // { 
+            rev = self.rev or "unknown"; 
+          } 
+        );
+    in {
       packages = {
         default = self.packages.${system}.c3c;
 
-        c3c = pkgs.callPackage ./nix/default.nix {};
+        c3c = call {};
 
         c3c-checks = pkgs.callPackage ./nix/default.nix { 
           checks = true; 

nix/default.nix

@@ -7,53 +7,46 @@
   libxml2,
   libffi,
   xar,
+  rev ? "unknown",
   debug ? false,
   checks ? false,
 }: let 
-  inherit (builtins) baseNameOf toString readFile elemAt;
-  inherit (lib.sources) cleanSourceWith cleanSource; 
+  inherit (builtins) readFile elemAt;
+  # inherit (lib.sources) cleanSourceWith cleanSource; 
   inherit (lib.lists) findFirst;
   inherit (lib.asserts) assertMsg;
-  inherit (lib.strings) hasInfix hasSuffix splitString removeSuffix removePrefix optionalString;
-in 
-llvmPackages.stdenv.mkDerivation (finalAttrs: {
+  inherit (lib.strings) hasInfix splitString removeSuffix removePrefix optionalString;
+in llvmPackages.stdenv.mkDerivation (finalAttrs: {
+
   pname = "c3c${optionalString debug "-debug"}";
+
   version = let
-    findLine = findFirst (x: hasInfix "COMPILER_VERSION" x) "none";
-    foundLine = findLine ( splitString "\n" ( readFile ../src/version.h ) );
-    version = removeSuffix "\"" ( removePrefix "\"" ( elemAt ( splitString " " foundLine ) 2 ) );
+    foundLine = findFirst (x: hasInfix "COMPILER_VERSION" x) "none" ( splitString "\n" ( readFile ../src/version.h ) );
   in 
     assert assertMsg (foundLine != "none") "No COMPILER_VERSION substring was found in version.h";
-    version;
-
-  src = cleanSourceWith {
-    filter = _path: _type: !(hasSuffix ".nix" (baseNameOf(toString _path)));
-    src = cleanSource ../.;
-  };
+    removeSuffix "\"" ( removePrefix "\"" ( elemAt ( splitString " " foundLine ) 2 ) );
 
+  src = ../.;
+
+  cmakeBuildType = if debug then "Debug" else "Release";
+
   postPatch = ''
-    substituteInPlace CMakeLists.txt \
-      --replace-fail "\''${LLVM_LIBRARY_DIRS}" "${llvmPackages.lld.lib}/lib ${llvmPackages.llvm.lib}/lib"
+    substituteInPlace git_hash.cmake \
+      --replace-fail "\''${GIT_HASH}" "${rev}"
   '';
 
-  cmakeBuildType = if debug then "Debug" else "Release";
-
   cmakeFlags = [
     "-DC3_ENABLE_CLANGD_LSP=${if debug then "ON" else "OFF"}"
+    "-DC3_LLD_DIR=${llvmPackages.lld.lib}/lib"
   ];
 
-  nativeBuildInputs = [ cmake ];
-
-  postBuild = optionalString debug ''
-    mkdir $out
-    substituteInPlace compile_commands.json \
-      --replace "/build/source/" "$src/"
-    cp compile_commands.json $out/compile_commands.json
-  '';
+  nativeBuildInputs = [ 
+    cmake 
+    llvmPackages.llvm
+    llvmPackages.lld 
+  ];
 
   buildInputs = [
-    llvmPackages.llvm
-    llvmPackages.lld
     curl
     libxml2
     libffi
@@ -70,13 +63,15 @@ llvmPackages.stdenv.mkDerivation (finalAttrs: {
     runHook postCheck
   '';
 
+
   meta = with lib; {
     description = "Compiler for the C3 language";
     homepage = "https://github.com/c3lang/c3c";
     license = licenses.lgpl3Only;
     maintainers = with maintainers; [
       luc65r
       anas
+      vssukharev
     ];
     platforms = platforms.all;
     mainProgram = "c3c";

nix/shell.nix

@@ -1,20 +1,22 @@
 {
+  lib,
   mkShell,
   clang-tools,
   c3c,
-}:
+}: 
+mkShell.override { 
+  inherit (c3c) stdenv; 
+} {
+  name = "c3c-shell";
 
-mkShell {
   inputsFrom = [
     c3c
   ];
 
   packages = [ 
     clang-tools 
-    c3c
   ];
 
-  shellHook = ''
-    ln -sf ${c3c}/compile_commands.json compile_commands.json
-  '';
+  # Usage: 'cmake . -Bbuild $C3_CMAKE_FLAGS' or 'cmake . -Bbuild $=C3_CMAKE_FLAGS' on zsh
+  C3_CMAKE_FLAGS = lib.concatStringsSep " " c3c.cmakeFlags;
 }