libstore: move command-specific settings to their own files

src/libstore/include/nix/store/globals.hh

@@ -735,29 +735,6 @@ public:
           duplicate files.
         )"};
 
-    Setting<bool> envKeepDerivations{
-        this,
-        false,
-        "keep-env-derivations",
-        R"(
-          If `false` (default), derivations are not stored in Nix user
-          environments. That is, the derivations of any build-time-only
-          dependencies may be garbage-collected.
-
-          If `true`, when you add a Nix derivation to a user environment, the
-          path of the derivation is stored in the user environment. Thus, the
-          derivation isn't garbage-collected until the user environment
-          generation is deleted (`nix-env --delete-generations`). To prevent
-          build-time-only dependencies from being collected, you should also
-          turn on `keep-outputs`.
-
-          The difference between this option and `keep-derivations` is that
-          this one is “sticky”: it applies to any user environment created
-          while this option was enabled, while `keep-derivations` only applies
-          at the moment the garbage collector is run.
-        )",
-        {"env-keep-derivations"}};
-
     Setting<SandboxMode> sandboxMode{
         this,
 #ifdef __linux__
@@ -1423,15 +1400,6 @@ public:
         true, // document default
         Xp::ConfigurableImpureEnv};
 
-    Setting<std::string> upgradeNixStorePathUrl{
-        this,
-        "https://github.com/NixOS/nixpkgs/raw/master/nixos/modules/installer/tools/nix-fallback-paths.nix",
-        "upgrade-nix-store-path-url",
-        R"(
-          Used by `nix upgrade-nix`, the URL of the file that contains the
-          store paths of the latest Nix release.
-        )"};
-
     Setting<uint64_t> warnLargePathThreshold{
         this,
         0,

src/nix/nix-env/nix-env.cc

@@ -5,6 +5,7 @@
 #include "nix/expr/eval.hh"
 #include "nix/expr/get-drvs.hh"
 #include "nix/store/globals.hh"
+#include "nix/util/config-global.hh"
 #include "nix/store/names.hh"
 #include "nix/store/profiles.hh"
 #include "nix/store/path-with-outputs.hh"
@@ -34,6 +35,39 @@
 using namespace nix;
 using std::cout;
 
+/**
+ * Settings related to Nix user environments.
+ */
+struct EnvSettings : Config
+{
+    Setting<bool> keepDerivations{
+        this,
+        false,
+        "keep-env-derivations",
+        R"(
+          If `false` (default), derivations are not stored in Nix user
+          environments. That is, the derivations of any build-time-only
+          dependencies may be garbage-collected.
+
+          If `true`, when you add a Nix derivation to a user environment, the
+          path of the derivation is stored in the user environment. Thus, the
+          derivation isn't garbage-collected until the user environment
+          generation is deleted (`nix-env --delete-generations`). To prevent
+          build-time-only dependencies from being collected, you should also
+          turn on `keep-outputs`.
+
+          The difference between this option and `keep-derivations` is that
+          this one is "sticky": it applies to any user environment created
+          while this option was enabled, while `keep-derivations` only applies
+          at the moment the garbage collector is run.
+        )",
+        {"env-keep-derivations"}};
+};
+
+EnvSettings envSettings;
+
+static GlobalConfig::Register rSettings(&envSettings);
+
 typedef enum { srcNixExprDrvs, srcNixExprs, srcStorePaths, srcProfile, srcAttrPath, srcUnknown } InstallSourceType;
 
 struct InstallSourceInfo
@@ -546,7 +580,7 @@ installDerivations(Globals & globals, const Strings & args, const Path & profile
         if (globals.dryRun)
             return;
 
-        if (createUserEnv(*globals.state, allElems, profile, settings.envKeepDerivations, lockToken))
+        if (createUserEnv(*globals.state, allElems, profile, envSettings.keepDerivations, lockToken))
             break;
     }
 }
@@ -657,7 +691,7 @@ static void upgradeDerivations(Globals & globals, const Strings & args, UpgradeT
         if (globals.dryRun)
             return;
 
-        if (createUserEnv(*globals.state, newElems, globals.profile, settings.envKeepDerivations, lockToken))
+        if (createUserEnv(*globals.state, newElems, globals.profile, envSettings.keepDerivations, lockToken))
             break;
     }
 }
@@ -716,7 +750,7 @@ static void opSetFlag(Globals & globals, Strings opFlags, Strings opArgs)
         checkSelectorUse(selectors);
 
         /* Write the new user environment. */
-        if (createUserEnv(*globals.state, installedElems, globals.profile, settings.envKeepDerivations, lockToken))
+        if (createUserEnv(*globals.state, installedElems, globals.profile, envSettings.keepDerivations, lockToken))
             break;
     }
 }
@@ -799,7 +833,7 @@ static void uninstallDerivations(Globals & globals, Strings & selectors, Path &
         if (globals.dryRun)
             return;
 
-        if (createUserEnv(*globals.state, workingElems, profile, settings.envKeepDerivations, lockToken))
+        if (createUserEnv(*globals.state, workingElems, profile, envSettings.keepDerivations, lockToken))
             break;
     }
 }

src/nix/upgrade-nix.cc

@@ -9,10 +9,33 @@
 #include "nix/store/names.hh"
 #include "nix/util/executable-path.hh"
 #include "nix/store/globals.hh"
+#include "nix/util/config-global.hh"
 #include "self-exe.hh"
 
 using namespace nix;
 
+/**
+ * Settings related to upgrading Nix itself.
+ */
+struct UpgradeSettings : Config
+{
+    /**
+     * The URL of the file that contains the store paths of the latest Nix release.
+     */
+    Setting<std::string> storePathUrl{
+        this,
+        "https://github.com/NixOS/nixpkgs/raw/master/nixos/modules/installer/tools/nix-fallback-paths.nix",
+        "upgrade-nix-store-path-url",
+        R"(
+          Used by `nix upgrade-nix`, the URL of the file that contains the
+          store paths of the latest Nix release.
+        )"};
+};
+
+UpgradeSettings upgradeSettings;
+
+static GlobalConfig::Register rSettings(&upgradeSettings);
+
 struct CmdUpgradeNix : MixDryRun, StoreCommand
 {
     std::filesystem::path profileDir;
@@ -31,7 +54,7 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand
             .longName = "nix-store-paths-url",
             .description = "The URL of the file that contains the store paths of the latest Nix release.",
             .labels = {"url"},
-            .handler = {&(std::string &) settings.upgradeNixStorePathUrl},
+            .handler = {&(std::string &) upgradeSettings.storePathUrl},
         });
     }
 
@@ -156,7 +179,7 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand
         Activity act(*logger, lvlInfo, actUnknown, "querying latest Nix version");
 
         // FIXME: use nixos.org?
-        auto req = FileTransferRequest(parseURL(settings.upgradeNixStorePathUrl.get()));
+        auto req = FileTransferRequest(parseURL(upgradeSettings.storePathUrl.get()));
         auto res = getFileTransfer()->download(req);
 
         auto state = std::make_unique<EvalState>(LookupPath{}, store, fetchSettings, evalSettings);