NixOS · Jan 22, 2020 · Jan 22, 2020 · Jan 22, 2020 · Jan 22, 2020 · Jan 22, 2020
diff --git a/src/libexpr/common-eval-args.cc b/src/libexpr/common-eval-args.cc
@@ -3,6 +3,8 @@
 #include "download.hh"
 #include "util.hh"
 #include "eval.hh"
+#include "fetchers/registry.hh"
+#include "flake/flakeref.hh"
 
 namespace nix {
 
@@ -40,7 +42,9 @@ MixEvalArgs::MixEvalArgs()
       .description("override a flake registry value")
       .arity(2)
       .handler([&](std::vector<std::string> ss) {
-          registryOverrides.push_back(std::make_pair(ss[0], ss[1]));
+          fetchers::overrideRegistry(
+              parseFlakeRef(ss[0], absPath(".")).input,
+              parseFlakeRef(ss[1], absPath(".")).input);
       });
 }
 

diff --git a/src/libexpr/common-eval-args.hh b/src/libexpr/common-eval-args.hh
@@ -16,8 +16,6 @@ struct MixEvalArgs : virtual Args
 
     Strings searchPath;
 
-    std::vector<std::pair<std::string, std::string>> registryOverrides;
-
 private:
 
     std::map<std::string, std::string> autoArgs;

diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc
@@ -302,7 +302,10 @@ static std::pair<Flake, LockedInput> updateLocks(
 
 /* Compute an in-memory lockfile for the specified top-level flake,
    and optionally write it to file, it the flake is writable. */
-ResolvedFlake resolveFlake(EvalState & state, const FlakeRef & topRef, HandleLockFile handleLockFile)
+LockedFlake lockFlake(
+    EvalState & state,
+    const FlakeRef & topRef,
+    HandleLockFile handleLockFile)
 {
     settings.requireExperimentalFeature("flakes");
 
@@ -356,12 +359,7 @@ ResolvedFlake resolveFlake(EvalState & state, const FlakeRef & topRef, HandleLoc
             warn("using updated lock file without writing it to file");
     }
 
-    return ResolvedFlake { .flake = std::move(flake), .lockFile = std::move(lockFile) };
-}
-
-void updateLockFile(EvalState & state, const FlakeRef & flakeRef, bool recreateLockFile)
-{
-    resolveFlake(state, flakeRef, recreateLockFile ? RecreateLockFile : UpdateLockFile);
+    return LockedFlake { .flake = std::move(flake), .lockFile = std::move(lockFile) };
 }
 
 static void emitSourceInfoAttrs(EvalState & state, const fetchers::Tree & sourceInfo, Value & vAttrs)
@@ -480,24 +478,24 @@ void callFlake(EvalState & state,
 }
 
 void callFlake(EvalState & state,
-    const ResolvedFlake & resFlake,
+    const LockedFlake & lockedFlake,
     Value & v)
 {
-    callFlake(state, resFlake.flake, resFlake.lockFile, v);
+    callFlake(state, lockedFlake.flake, lockedFlake.lockFile, v);
 }
 
 // This function is exposed to be used in nix files.
 static void prim_getFlake(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
-    callFlake(state, resolveFlake(state, parseFlakeRef(state.forceStringNoCtx(*args[0], pos)),
+    callFlake(state, lockFlake(state, parseFlakeRef(state.forceStringNoCtx(*args[0], pos)),
             evalSettings.pureEval ? AllPure : UseUpdatedLockFile), v);
 }
 
 static RegisterPrimOp r2("getFlake", 1, prim_getFlake);
 
 }
 
-Fingerprint ResolvedFlake::getFingerprint() const
+Fingerprint LockedFlake::getFingerprint() const
 {
     // FIXME: as an optimization, if the flake contains a lock file
     // and we haven't changed it, then it's sufficient to use

diff --git a/src/libexpr/flake/flake.hh b/src/libexpr/flake/flake.hh
@@ -33,7 +33,7 @@ struct Flake
 {
     FlakeRef originalRef;
     FlakeRef resolvedRef;
-    std::string description;
+    std::optional<std::string> description;
     std::shared_ptr<const fetchers::Tree> sourceInfo;
     std::map<FlakeId, FlakeInput> inputs;
     Value * vOutputs; // FIXME: gc
@@ -46,27 +46,25 @@ Flake getFlake(EvalState & state, const FlakeRef & flakeRef, bool allowLookup);
 /* Fingerprint of a locked flake; used as a cache key. */
 typedef Hash Fingerprint;
 
-struct ResolvedFlake
+struct LockedFlake
 {
     Flake flake;
     LockFile lockFile;
 
     Fingerprint getFingerprint() const;
 };
 
-ResolvedFlake resolveFlake(EvalState &, const FlakeRef &, HandleLockFile);
+LockedFlake lockFlake(EvalState &, const FlakeRef &, HandleLockFile);
 
 void callFlake(EvalState & state,
     const Flake & flake,
     const LockedInputs & inputs,
     Value & v);
 
 void callFlake(EvalState & state,
-    const ResolvedFlake & resFlake,
+    const LockedFlake & resFlake,
     Value & v);
 
-void updateLockFile(EvalState &, const FlakeRef & flakeRef, bool recreateLockFile);
-
 }
 
 }
diff --git a/src/libstore/fetchers/fetchers.hh b/src/libstore/fetchers/fetchers.hh
@@ -27,6 +27,8 @@ struct Input : std::enable_shared_from_this<Input>
     std::string type;
     std::optional<Hash> narHash;
 
+    virtual ~Input() { }
+
     virtual bool operator ==(const Input & other) const { return false; }
 
     virtual bool isDirect() const { return true; }
@@ -63,6 +65,8 @@ struct ParsedURL;
 
 struct InputScheme
 {
+    virtual ~InputScheme() { }
+
     virtual std::unique_ptr<Input> inputFromURL(const ParsedURL & url) = 0;
 };
 

diff --git a/src/libstore/fetchers/git.cc b/src/libstore/fetchers/git.cc
@@ -142,7 +142,7 @@ struct GitInput : Input
         return res;
     }
 
-    std::optional<Path> getSourcePath() const
+    std::optional<Path> getSourcePath() const override
     {
         if (url.scheme == "git+file" && !ref && !rev)
             return url.path;
@@ -172,7 +172,8 @@ struct GitInput : Input
                 return {std::move(*tree), input};
         }
 
-        auto [isLocal, actualUrl] = getActualUrl();
+        auto [isLocal, actualUrl_] = getActualUrl();
+        auto actualUrl = actualUrl_; // work around clang bug
 
         // If this is a local directory and no ref or revision is
         // given, then allow the use of an unclean working tree.

diff --git a/src/libstore/fetchers/mercurial.cc b/src/libstore/fetchers/mercurial.cc
@@ -84,7 +84,8 @@ struct MercurialInput : Input
 
         auto input = std::make_shared<MercurialInput>(*this);
 
-        auto [isLocal, actualUrl] = getActualUrl();
+        auto [isLocal, actualUrl_] = getActualUrl();
+        auto actualUrl = actualUrl_; // work around clang bug
 
         // FIXME: return lastModified.
 

diff --git a/src/libstore/fetchers/registry.cc b/src/libstore/fetchers/registry.cc
@@ -11,11 +11,10 @@ namespace nix::fetchers {
 std::shared_ptr<Registry> Registry::read(
     const Path & path, RegistryType type)
 {
-    auto registry = std::make_shared<Registry>();
-    registry->type = type;
+    auto registry = std::make_shared<Registry>(type);
 
     if (!pathExists(path))
-        return std::make_shared<Registry>();
+        return std::make_shared<Registry>(type);
 
     auto json = nlohmann::json::parse(readFile(path));
 
@@ -74,17 +73,20 @@ std::shared_ptr<Registry> getUserRegistry()
     return Registry::read(getUserRegistryPath(), Registry::User);
 }
 
-#if 0
-std::shared_ptr<Registry> getFlagRegistry(RegistryOverrides registryOverrides)
+static std::shared_ptr<Registry> flagRegistry =
+    std::make_shared<Registry>(Registry::Flag);
+
+std::shared_ptr<Registry> getFlagRegistry()
 {
-    auto flagRegistry = std::make_shared<Registry>();
-    for (auto const & x : registryOverrides)
-        flagRegistry->entries.insert_or_assign(
-            parseFlakeRef2(x.first),
-            parseFlakeRef2(x.second));
     return flagRegistry;
 }
-#endif
+
+void overrideRegistry(
+    const std::shared_ptr<const Input> & from,
+    const std::shared_ptr<const Input> & to)
+{
+    flagRegistry->add(from, to);
+}
 
 static std::shared_ptr<Registry> getGlobalRegistry(ref<Store> store)
 {
@@ -107,7 +109,7 @@ static std::shared_ptr<Registry> getGlobalRegistry(ref<Store> store)
 Registries getRegistries(ref<Store> store)
 {
     Registries registries;
-    //registries.push_back(getFlagRegistry(registryOverrides));
+    registries.push_back(getFlagRegistry());
     registries.push_back(getUserRegistry());
     registries.push_back(getGlobalRegistry(store));
     return registries;

diff --git a/src/libstore/fetchers/registry.hh b/src/libstore/fetchers/registry.hh
@@ -20,6 +20,10 @@ struct Registry
 
     std::vector<std::pair<std::shared_ptr<const Input>, std::shared_ptr<const Input>>> entries;
 
+    Registry(RegistryType type)
+        : type(type)
+    { }
+
     static std::shared_ptr<Registry> read(
         const Path & path, RegistryType type);
 
@@ -40,6 +44,10 @@ Path getUserRegistryPath();
 
 Registries getRegistries(ref<Store> store);
 
+void overrideRegistry(
+    const std::shared_ptr<const Input> & from,
+    const std::shared_ptr<const Input> & to);
+
 std::shared_ptr<const Input> lookupInRegistries(
     ref<Store> store,
     std::shared_ptr<const Input> input);

diff --git a/src/nix/flake.cc b/src/nix/flake.cc
@@ -41,9 +41,9 @@ class FlakeCommand : virtual Args, public EvalCommand, public MixFlakeOptions
         return flake::getFlake(*evalState, getFlakeRef(), useRegistries);
     }
 
-    ResolvedFlake resolveFlake()
+    LockedFlake lockFlake()
     {
-        return flake::resolveFlake(*getEvalState(), getFlakeRef(), getLockFileMode());
+        return flake::lockFlake(*getEvalState(), getFlakeRef(), getLockFileMode());
     }
 };
 
@@ -80,7 +80,8 @@ static void printFlakeInfo(const Store & store, const Flake & flake)
 {
     std::cout << fmt("URL:           %s\n", flake.resolvedRef.input->to_string());
     std::cout << fmt("Edition:       %s\n", flake.edition);
-    std::cout << fmt("Description:   %s\n", flake.description);
+    if (flake.description)
+        std::cout << fmt("Description:   %s\n", *flake.description);
     std::cout << fmt("Path:          %s\n", store.printStorePath(flake.sourceInfo->storePath));
     if (flake.sourceInfo->rev)
         std::cout << fmt("Revision:      %s\n", flake.sourceInfo->rev->to_string(Base16, false));
@@ -94,7 +95,8 @@ static void printFlakeInfo(const Store & store, const Flake & flake)
 static nlohmann::json flakeToJson(const Store & store, const Flake & flake)
 {
     nlohmann::json j;
-    j["description"] = flake.description;
+    if (flake.description)
+        j["description"] = *flake.description;
     j["edition"] = flake.edition;
     j["url"] = flake.resolvedRef.input->to_string();
     if (flake.sourceInfo->rev)
@@ -120,16 +122,16 @@ struct CmdFlakeDeps : FlakeCommand
     {
         auto evalState = getEvalState();
 
-        std::queue<ResolvedFlake> todo;
-        todo.push(resolveFlake());
+        std::queue<LockedFlake> todo;
+        todo.push(lockFlake());
 
         stopProgressBar();
 
         while (!todo.empty()) {
-            auto resFlake = std::move(todo.front());
+            auto lockedFlake = std::move(todo.front());
             todo.pop();
 
-            for (auto & info : resFlake.flakeDeps) {
+            for (auto & info : lockedFlake.flakeDeps) {
                 printFlakeInfo(*store, info.second.flake);
                 todo.push(info.second);
             }
@@ -148,15 +150,7 @@ struct CmdFlakeUpdate : FlakeCommand
     void run(nix::ref<nix::Store> store) override
     {
         auto evalState = getEvalState();
-
-        auto flakeRef = getFlakeRef();
-
-#if 0
-        if (std::get_if<FlakeRef::IsPath>(&flakeRef.data))
-            updateLockFile(*evalState, flakeRef, true);
-        else
-            throw Error("cannot update lockfile of flake '%s'", flakeRef);
-#endif
+        lockFlake();
     }
 };
 
@@ -185,7 +179,7 @@ struct CmdFlakeInfo : FlakeCommand, MixJSON
     {
         if (json) {
             auto state = getEvalState();
-            auto flake = resolveFlake();
+            auto flake = lockFlake();
 
             auto json = flakeToJson(*store, flake.flake);
 
@@ -241,7 +235,7 @@ struct CmdFlakeCheck : FlakeCommand, MixJSON
         settings.readOnlyMode = !build;
 
         auto state = getEvalState();
-        auto flake = resolveFlake();
+        auto flake = lockFlake();
 
         auto checkSystemName = [&](const std::string & system, const Pos & pos) {
             // FIXME: what's the format of "system"?