Make Path std::filesystem::path not std::string

src/build-remote/build-remote.cc

@@ -81,11 +81,11 @@ static int main_build_remote(int argc, char * * argv)
 
         /* It would be more appropriate to use $XDG_RUNTIME_DIR, since
            that gets cleared on reboot, but it wouldn't work on macOS. */
-        auto currentLoadName = "/current-load";
+        PathView currentLoadName = "current-load";
         if (auto localStore = store.dynamic_pointer_cast<LocalFSStore>())
-            currentLoad = std::string { localStore->stateDir } + currentLoadName;
+            currentLoad = localStore->stateDir / currentLoadName;
         else
-            currentLoad = settings.nixStateDir + currentLoadName;
+            currentLoad = settings.nixStateDir / currentLoadName.native();
 
         std::shared_ptr<Store> sshStore;
         AutoCloseFD bestSlotLock;

src/libcmd/common-eval-args.cc

@@ -192,7 +192,7 @@ Bindings * MixEvalArgs::getAutoArgs(EvalState & state)
     return res.finish();
 }
 
-SourcePath lookupFileArg(EvalState & state, std::string_view s, const Path * baseDir)
+SourcePath lookupFileArg(EvalState & state, PathView s, const Path * baseDir)
 {
     if (EvalSettings::isPseudoUrl(s)) {
         auto accessor = fetchers::downloadTarball(

src/libcmd/common-eval-args.hh

@@ -41,6 +41,6 @@ private:
 /**
  * @param baseDir Optional [base directory](https://nixos.org/manual/nix/unstable/glossary#gloss-base-directory)
  */
-SourcePath lookupFileArg(EvalState & state, std::string_view s, const Path * baseDir = nullptr);
+SourcePath lookupFileArg(EvalState & state, PathView s, const Path * baseDir = nullptr);
 
 }

src/libexpr/eval-settings.cc

@@ -58,7 +58,7 @@ Strings EvalSettings::getDefaultNixPath()
             if (s.empty()) {
                 res.push_back(p);
             } else {
-                res.push_back(s + "=" + p);
+                res.push_back(s + "=" + p.native());
             }
         }
     };

src/libstore/globals.cc

@@ -84,7 +84,9 @@ Settings::Settings()
     }
 
 #if defined(__linux__) && defined(SANDBOX_SHELL)
-    sandboxPaths = tokenizeString<StringSet>("/bin/sh=" SANDBOX_SHELL);
+    sandboxPaths = std::set {
+        Path { "/bin/sh=" SANDBOX_SHELL }
+    };
 #endif
 
     /* chroot-like behavior from Apple's sandbox */
@@ -154,7 +156,7 @@ std::vector<Path> getUserConfigFiles()
     // Use the paths specified in NIX_USER_CONF_FILES if it has been defined
     auto nixConfFiles = getEnv("NIX_USER_CONF_FILES");
     if (nixConfFiles.has_value()) {
-        return tokenizeString<std::vector<std::string>>(nixConfFiles.value(), ":");
+        return tokenizeString<std::vector<Path>>(nixConfFiles.value(), ":");
     }
 
     // Use the paths specified by the XDG spec

src/libstore/globals.hh

@@ -276,7 +276,7 @@ public:
         )"};
 
     Setting<std::string> builders{
-        this, "@" + nixConfDir + "/machines", "builders",
+        this, "@" + (nixConfDir / "machines").native(), "builders",
         R"(
           A semicolon- or newline-separated list of build machines.
 

src/libstore/http-binary-cache-store.cc

@@ -26,7 +26,7 @@ class HttpBinaryCacheStore : public virtual HttpBinaryCacheStoreConfig, public v
 {
 private:
 
-    Path cacheUri;
+    std::string cacheUri;
 
     struct State
     {
@@ -40,7 +40,7 @@ class HttpBinaryCacheStore : public virtual HttpBinaryCacheStoreConfig, public v
 
     HttpBinaryCacheStore(
         const std::string & scheme,
-        const Path & _cacheUri,
+        const std::string & _cacheUri,
         const Params & params)
         : StoreConfig(params)
         , BinaryCacheStoreConfig(params)

src/libstore/local-binary-cache-store.cc

@@ -45,7 +45,7 @@ class LocalBinaryCacheStore : public virtual LocalBinaryCacheStoreConfig, public
 
     std::string getUri() override
     {
-        return "file://" + binaryCacheDir;
+        return "file://" + binaryCacheDir.native();
     }
 
     static std::set<std::string> uriSchemes();

src/libstore/local-fs-store.hh

@@ -16,17 +16,17 @@ struct LocalFSStoreConfig : virtual StoreConfig
         "Directory prefixed to all other paths."};
 
     const PathSetting stateDir{this,
-        rootDir.get() ? *rootDir.get() + "/nix/var/nix" : settings.nixStateDir,
+        rootDir.get() ? *rootDir.get() / "nix/var/nix" : settings.nixStateDir,
         "state",
         "Directory where Nix will store state."};
 
     const PathSetting logDir{this,
-        rootDir.get() ? *rootDir.get() + "/nix/var/log/nix" : settings.nixLogDir,
+        rootDir.get() ? *rootDir.get() / "nix/var/log/nix" : settings.nixLogDir,
         "log",
         "directory where Nix will store log files."};
 
     const PathSetting realStoreDir{this,
-        rootDir.get() ? *rootDir.get() + "/nix/store" : storeDir, "real",
+        rootDir.get() ? *rootDir.get() / "nix/store" : storeDir, "real",
         "Physical path of the Nix store."};
 };
 
@@ -66,7 +66,7 @@ public:
     Path toRealPath(const Path & storePath) override
     {
         assert(isInStore(storePath));
-        return getRealStoreDir() + "/" + std::string(storePath, storeDir.size() + 1);
+        return getRealStoreDir() / Path::string_type { storePath, storeDir.native().size() + 1 };
     }
 
     std::optional<std::string> getBuildLogExact(const StorePath & path) override;

src/libstore/nar-accessor.cc

@@ -15,7 +15,9 @@ struct NarMember
 
     std::string target;
 
-    /* If this is a directory, all the children of the directory. */
+    /**
+     * If this is a directory, all the children of the directory.
+     */
     std::map<std::string, NarMember> children;
 };
 

src/libstore/nar-info-disk-cache.cc

@@ -208,7 +208,10 @@ class NarInfoDiskCacheImpl : public NarInfoDiskCache
             };
 
             {
-                auto r(state->insertCache.use()(uri)(time(0))(storeDir)(wantMassQuery)(priority));
+                auto r {
+                    state->insertCache.use()
+                        (uri)(time(0))(storeDir.native())(wantMassQuery)(priority)
+                };
                 if (!r.next()) { abort(); }
                 ret.id = (int) r.getInt(0);
             }

src/libstore/pathlocks.hh

@@ -2,6 +2,7 @@
 ///@file
 
 #include "file-descriptor.hh"
+#include "file-path.hh"
 
 namespace nix {
 

src/libstore/profiles.cc

@@ -39,7 +39,7 @@ std::pair<Generations, std::optional<GenerationNumber>> findGenerations(Path pro
 
     for (auto & i : readDirectory(profileDir)) {
         if (auto n = parseName(profileName, i.name)) {
-            auto path = profileDir + "/" + i.name;
+            auto path = profileDir / i.name;
             gens.push_back({
                 .number = *n,
                 .path = path,
@@ -255,7 +255,7 @@ time_t parseOlderThanTimeSpec(std::string_view timeSpec)
 void switchLink(Path link, Path target)
 {
     /* Hacky. */
-    if (dirOf(target) == dirOf(link)) target = baseNameOf(target);
+    if (dirOf(target) == dirOf(link)) target = baseNameOf(target).native();
 
     replaceSymlink(target, link);
 }
@@ -310,28 +310,30 @@ Path profilesDir()
     auto profileRoot =
         isRootUser()
         ? rootProfilesDir()
-        : createNixStateDir() + "/profiles";
+        : createNixStateDir() / "profiles";
     createDirs(profileRoot);
     return profileRoot;
 }
 
 Path rootProfilesDir()
 {
-    return settings.nixStateDir + "/profiles/per-user/root";
+    return settings.nixStateDir / "profiles/per-user/root";
 }
 
 
 Path getDefaultProfile()
 {
-    Path profileLink = settings.useXDGBaseDirectories ? createNixStateDir() + "/profile" : getHome() + "/.nix-profile";
+    Path profileLink = settings.useXDGBaseDirectories
+        ? createNixStateDir() / "profile"
+        : getHome() / ".nix-profile";
     try {
-        auto profile = profilesDir() + "/profile";
+        auto profile = profilesDir() / "profile";
         if (!pathExists(profileLink)) {
             replaceSymlink(profile, profileLink);
         }
         // Backwards compatibiliy measure: Make root's profile available as
         // `.../default` as it's what NixOS and most of the init scripts expect
-        Path globalProfileLink = settings.nixStateDir + "/profiles/default";
+        Path globalProfileLink = settings.nixStateDir / "profiles/default";
         if (isRootUser() && !pathExists(globalProfileLink)) {
             replaceSymlink(profile, globalProfileLink);
         }
@@ -343,12 +345,12 @@ Path getDefaultProfile()
 
 Path defaultChannelsDir()
 {
-    return profilesDir() + "/channels";
+    return profilesDir() / "channels";
 }
 
 Path rootChannelsDir()
 {
-    return rootProfilesDir() + "/channels";
+    return rootProfilesDir() / "channels";
 }
 
 }

src/libstore/sqlite.cc

@@ -62,7 +62,7 @@ SQLite::SQLite(const Path & path, SQLiteOpenMode mode)
     bool immutable = mode == SQLiteOpenMode::Immutable;
     int flags = immutable ? SQLITE_OPEN_READONLY : SQLITE_OPEN_READWRITE;
     if (mode == SQLiteOpenMode::Normal) flags |= SQLITE_OPEN_CREATE;
-    auto uri = "file:" + percentEncode(path) + "?immutable=" + (immutable ? "1" : "0");
+    auto uri = "file:" + percentEncode(path.native()) + "?immutable=" + (immutable ? "1" : "0");
     int ret = sqlite3_open_v2(uri.c_str(), &db, SQLITE_OPEN_URI | flags, vfs);
     if (ret != SQLITE_OK) {
         const char * err = sqlite3_errstr(ret);

src/libstore/sqlite.hh

@@ -5,6 +5,7 @@
 #include <string>
 
 #include "error.hh"
+#include "file-path.hh"
 
 struct sqlite3;
 struct sqlite3_stmt;

src/libstore/ssh.cc

@@ -35,7 +35,7 @@ void SSHMaster::addCommonSSHOpts(Strings & args)
         auto p = host.rfind("@");
         std::string thost = p != std::string::npos ? std::string(host, p + 1) : host;
         writeFile(fileName, thost + " " + base64Decode(sshPublicHostKey) + "\n");
-        args.insert(args.end(), {"-oUserKnownHostsFile=" + fileName});
+        args.insert(args.end(), {"-oUserKnownHostsFile=" + fileName.native()});
     }
     if (compress)
         args.push_back("-C");

src/libstore/store-api.hh

@@ -224,13 +224,13 @@ public:
     /**
      * Follow symlinks until we end up with a path in the Nix store.
      */
-    Path followLinksToStore(std::string_view path) const;
+    Path followLinksToStore(PathView path) const;
 
     /**
      * Same as followLinksToStore(), but apply toStorePath() to the
      * result.
      */
-    StorePath followLinksToStorePath(std::string_view path) const;
+    StorePath followLinksToStorePath(PathView path) const;
 
     /**
      * Check whether a path is valid.

src/libstore/store-dir-config.hh

@@ -67,7 +67,7 @@ struct StoreDirConfig : public Config
      * @return true if ‘path’ is a store path, i.e. a direct child of the
      * Nix store.
      */
-    bool isStorePath(std::string_view path) const;
+    bool isStorePath(PathView path) const;
 
     /**
      * Split a path like /nix/store/<hash>-<name>/<bla> into

src/libstore/uds-remote-store.cc

@@ -52,7 +52,7 @@ UDSRemoteStore::UDSRemoteStore(
 std::string UDSRemoteStore::getUri()
 {
     if (path) {
-        return std::string("unix://") + *path;
+        return std::string { "unix://" } + path->native();
     } else {
         return "daemon";
     }

src/libstore/uds-remote-store.hh

@@ -60,7 +60,7 @@ private:
     };
 
     ref<RemoteStore::Connection> openConnection() override;
-    std::optional<std::string> path;
+    std::optional<Path> path;
 };
 
 }

src/libstore/unix/lock.cc

@@ -50,7 +50,7 @@ struct SimpleUserLock : UserLock
     static std::unique_ptr<UserLock> acquire()
     {
         assert(settings.buildUsersGroup != "");
-        createDirs(settings.nixStateDir + "/userpool");
+        createDirs(settings.nixStateDir / "userpool");
 
         /* Get the members of the build-users-group. */
         struct group * gr = getgrnam(settings.buildUsersGroup.get().c_str());
@@ -139,14 +139,14 @@ struct AutoUserLock : UserLock
         assert((uint64_t) settings.startId + (uint64_t) settings.uidCount <= std::numeric_limits<uid_t>::max());
         assert(nrIds <= maxIdsPerBuild);
 
-        createDirs(settings.nixStateDir + "/userpool2");
+        createDirs(settings.nixStateDir / "userpool2");
 
         size_t nrSlots = settings.uidCount / maxIdsPerBuild;
 
         for (size_t i = 0; i < nrSlots; i++) {
             debug("trying user slot '%d'", i);
 
-            createDirs(settings.nixStateDir + "/userpool2");
+            createDirs(settings.nixStateDir / "userpool2");
 
             auto fnUserLock = fmt("%s/userpool2/slot-%d", settings.nixStateDir, i);
 

src/libutil/archive.cc

@@ -30,7 +30,7 @@ static ArchiveSettings archiveSettings;
 
 static GlobalConfig::Register rArchiveSettings(&archiveSettings);
 
-PathFilter defaultPathFilter = [](const Path &) { return true; };
+PathFilter defaultPathFilter = [](PathView) { return true; };
 
 
 void SourceAccessor::dumpPath(
@@ -97,7 +97,7 @@ void SourceAccessor::dumpPath(
         }
 
         else if (st.type == tSymlink)
-            sink << "type" << "symlink" << "target" << readLink(path);
+            sink << "type" << "symlink" << "target" << readLink(path).string();
 
         else throw Error("file '%s' has an unsupported type", path);
 

src/libutil/archive.hh

@@ -8,7 +8,6 @@
 
 namespace nix {
 
-
 /**
  * dumpPath creates a Nix archive of the specified path.
  *

src/libutil/args.hh

@@ -113,6 +113,11 @@ protected:
             , arity(1)
         { }
 
+        Handler(Path * dest)
+            : fun([=](std::vector<std::string> ss) { *dest = ss[0]; })
+            , arity(1)
+        { }
+
         template<class T>
         Handler(T * dest, const T & val)
             : fun([dest, val](std::vector<std::string> ss) { *dest = val; })
@@ -283,6 +288,18 @@ public:
         });
     }
 
+    /**
+     * Expect a path argument.
+     */
+    void expectArg(const std::string & label, Path * dest, bool optional = false)
+    {
+        expectArgs({
+            .label = label,
+            .optional = optional,
+            .handler = {dest}
+        });
+    }
+
     /**
      * Expect 0 or more arguments.
      */