nixos-option: fix build against nix 2.24

pkgs/tools/nix/nixos-option/default.nix

@@ -1,34 +1,35 @@
-{ lib
-, stdenv
-, boost
-, cmake
-, pkg-config
-, installShellFiles
-, nix
+{
+  lib,
+  stdenv,
+  boost,
+  meson,
+  ninja,
+  pkg-config,
+  installShellFiles,
+  nix,
 }:
 
 stdenv.mkDerivation {
   name = "nixos-option";
 
-  src = ./src;
+  src = ./.;
 
   postInstall = ''
-    installManPage ${./nixos-option.8}
+    installManPage ../nixos-option.8
   '';
 
   strictDeps = true;
+
   nativeBuildInputs = [
-    cmake
+    meson
+    ninja
     pkg-config
     installShellFiles
   ];
   buildInputs = [
     boost
     nix
   ];
-  cmakeFlags = [
-    "-DNIX_DEV_INCLUDEPATH=${nix.dev}/include/nix"
-  ];
 
   meta = with lib; {
     license = licenses.lgpl2Plus;

pkgs/tools/nix/nixos-option/meson.build

@@ -0,0 +1,15 @@
+project('nixos-option', 'cpp',
+  version : '0.1.6',
+  license : 'GPL-3.0',
+)
+
+nix_main_dep = dependency('nix-main', required: true)
+nix_store_dep = dependency('nix-store', required: true)
+nix_expr_dep = dependency('nix-expr', required: true)
+nix_cmd_dep = dependency('nix-cmd', required: true)
+nix_flake_dep = dependency('nix-flake', required: true)
+threads_dep = dependency('threads', required: true)
+nlohmann_json_dep = dependency('nlohmann_json', required: true)
+boost_dep = dependency('boost', required: true)
+
+subdir('src')

pkgs/tools/nix/nixos-option/src/libnix-copy-paste.cc

@@ -2,79 +2,21 @@
 // Since they are not, copy/paste them here.
 // TODO: Delete these and use the ones in the library as they become available.
 
-#include <nix/config.h> // for nix/globals.hh's reference to SYSTEM
-
 #include "libnix-copy-paste.hh"
-#include <boost/format/alt_sstream.hpp>           // for basic_altstringbuf...
-#include <boost/format/alt_sstream_impl.hpp>      // for basic_altstringbuf...
-#include <boost/optional/optional.hpp>            // for get_pointer
-#include <iostream>                               // for operator<<, basic_...
-#include <nix/types.hh>                           // for Strings
-#include <nix/error.hh>                           // for Error
-#include <string>                                 // for string, basic_string
-
-using nix::Error;
-using nix::Strings;
-using std::string;
-
-// From nix/src/libexpr/attr-path.cc
-Strings parseAttrPath(const string & s)
-{
-    Strings res;
-    string cur;
-    string::const_iterator i = s.begin();
-    while (i != s.end()) {
-        if (*i == '.') {
-            res.push_back(cur);
-            cur.clear();
-        } else if (*i == '"') {
-            ++i;
-            while (1) {
-                if (i == s.end())
-                    throw Error("missing closing quote in selection path '%1%'", s);
-                if (*i == '"')
-                    break;
-                cur.push_back(*i++);
-            }
-        } else
-            cur.push_back(*i);
-        ++i;
-    }
-    if (!cur.empty())
-        res.push_back(cur);
-    return res;
-}
+#include <nix/print.hh>                           // for Strings
 
 // From nix/src/nix/repl.cc
-bool isVarName(const string & s)
+bool isVarName(const std::string_view & s)
 {
-    if (s.size() == 0)
-        return false;
+    if (s.size() == 0) return false;
+    if (nix::isReservedKeyword(s)) return false;
     char c = s[0];
-    if ((c >= '0' && c <= '9') || c == '-' || c == '\'')
-        return false;
+    if ((c >= '0' && c <= '9') || c == '-' || c == '\'') return false;
     for (auto & i : s)
-        if (!((i >= 'a' && i <= 'z') || (i >= 'A' && i <= 'Z') || (i >= '0' && i <= '9') || i == '_' || i == '-' ||
-              i == '\''))
+        if (!((i >= 'a' && i <= 'z') ||
+              (i >= 'A' && i <= 'Z') ||
+              (i >= '0' && i <= '9') ||
+              i == '_' || i == '-' || i == '\''))
             return false;
     return true;
 }
-
-// From nix/src/nix/repl.cc
-std::ostream & printStringValue(std::ostream & str, const char * string)
-{
-    str << "\"";
-    for (const char * i = string; *i; i++)
-        if (*i == '\"' || *i == '\\')
-            str << "\\" << *i;
-        else if (*i == '\n')
-            str << "\\n";
-        else if (*i == '\r')
-            str << "\\r";
-        else if (*i == '\t')
-            str << "\\t";
-        else
-            str << *i;
-    str << "\"";
-    return str;
-}

pkgs/tools/nix/nixos-option/src/libnix-copy-paste.hh

@@ -1,9 +1,5 @@
 #pragma once
 
-#include <iostream>
 #include <nix/types.hh>
-#include <string>
 
-nix::Strings parseAttrPath(const std::string & s);
-bool isVarName(const std::string & s);
-std::ostream & printStringValue(std::ostream & str, const char * string);
+bool isVarName(const std::string_view & s);

pkgs/tools/nix/nixos-option/src/meson.build

@@ -0,0 +1,20 @@
+src = [
+  'nixos-option.cc',
+  'libnix-copy-paste.cc',
+]
+
+cc = meson.get_compiler('cpp')
+
+executable('nixos-option', src,
+           dependencies : [
+             nix_main_dep,
+             nix_store_dep,
+             nix_expr_dep,
+             nix_cmd_dep,
+             nix_flake_dep,
+             boost_dep,
+             nlohmann_json_dep,
+             threads_dep
+           ],
+           install: true,
+           cpp_args: ['-std=c++2a', '--include', 'nix/config.h'])