Replace some `bool recursive` with a new `FileIngestionMethod` enum

27 files changed, 105 insertions, 87 deletions

diff --git a/perl/lib/Nix/Store.xs b/perl/lib/Nix/Store.xs
index 1ca734e75..eab8ccacb 100644
--- a/perl/lib/Nix/Store.xs
+++ b/perl/lib/Nix/Store.xs
@@ -274,7 +274,7 @@ int checkSignature(SV * publicKey_, SV * sig_, char * msg)
 SV * addToStore(char * srcPath, int recursive, char * algo)
     PPCODE:
         try {
-            auto path = store()->addToStore(std::string(baseNameOf(srcPath)), srcPath, recursive, parseHashType(algo));
+            auto path = store()->addToStore(std::string(baseNameOf(srcPath)), srcPath, (FileIngestionMethod) recursive, parseHashType(algo));
             XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(path).c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
@@ -285,7 +285,7 @@ SV * makeFixedOutputPath(int recursive, char * algo, char * hash, char * name)
     PPCODE:
         try {
             Hash h(hash, parseHashType(algo));
-            auto path = store()->makeFixedOutputPath(recursive, h, name);
+            auto path = store()->makeFixedOutputPath((FileIngestionMethod) recursive, h, name);
             XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(path).c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index dac32b6f5..88bbf3b32 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -1661,7 +1661,7 @@ string EvalState::copyPathToStore(PathSet & context, const Path & path)
     else {
         auto p = settings.readOnlyMode
             ? store->computeStorePathForPath(std::string(baseNameOf(path)), checkSourcePath(path)).first
-            : store->addToStore(std::string(baseNameOf(path)), checkSourcePath(path), true, htSHA256, defaultPathFilter, repair);
+            : store->addToStore(std::string(baseNameOf(path)), checkSourcePath(path), FileIngestionMethod::Recursive, htSHA256, defaultPathFilter, repair);
         dstPath = store->printStorePath(p);
         srcToStore.insert_or_assign(path, std::move(p));
         printMsg(lvlChatty, "copied source '%1%' -> '%2%'", path, dstPath);
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 8de234951..7d45733f4 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -563,7 +563,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
 
     std::optional<std::string> outputHash;
     std::string outputHashAlgo;
-    bool outputHashRecursive = false;
+    FileIngestionMethod outputHashRecursive = FileIngestionMethod::Flat;
 
     StringSet outputs;
     outputs.insert("out");
@@ -574,8 +574,8 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
         vomit("processing attribute '%1%'", key);
 
         auto handleHashMode = [&](const std::string & s) {
-            if (s == "recursive") outputHashRecursive = true;
-            else if (s == "flat") outputHashRecursive = false;
+            if (s == "recursive") outputHashRecursive = FileIngestionMethod::Recursive;
+            else if (s == "flat") outputHashRecursive = FileIngestionMethod::Flat;
             else throw EvalError("invalid value '%s' for 'outputHashMode' attribute, at %s", s, posDrvName);
         };
 
@@ -725,7 +725,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
         auto outPath = state.store->makeFixedOutputPath(outputHashRecursive, h, drvName);
         if (!jsonObject) drv.env["out"] = state.store->printStorePath(outPath);
         drv.outputs.insert_or_assign("out", DerivationOutput(std::move(outPath),
-                (outputHashRecursive ? "r:" : "") + printHashType(h.type),
+                (static_cast<bool>(outputHashRecursive) ? "r:" : "") + printHashType(h.type),
                 h.to_string(Base16, false)));
     }
 
@@ -1038,7 +1038,7 @@ static void prim_toFile(EvalState & state, const Pos & pos, Value * * args, Valu
 
 
 static void addPath(EvalState & state, const Pos & pos, const string & name, const Path & path_,
-    Value * filterFun, bool recursive, const Hash & expectedHash, Value & v)
+    Value * filterFun, FileIngestionMethod recursive, const Hash & expectedHash, Value & v)
 {
     const auto path = evalSettings.pureEval && expectedHash ?
         path_ :
@@ -1095,7 +1095,7 @@ static void prim_filterSource(EvalState & state, const Pos & pos, Value * * args
     if (args[0]->type != tLambda)
         throw TypeError(format("first argument in call to 'filterSource' is not a function but %1%, at %2%") % showType(*args[0]) % pos);
 
-    addPath(state, pos, std::string(baseNameOf(path)), path, args[0], true, Hash(), v);
+    addPath(state, pos, std::string(baseNameOf(path)), path, args[0], FileIngestionMethod::Recursive, Hash(), v);
 }
 
 static void prim_path(EvalState & state, const Pos & pos, Value * * args, Value & v)
@@ -1104,7 +1104,7 @@ static void prim_path(EvalState & state, const Pos & pos, Value * * args, Value
     Path path;
     string name;
     Value * filterFun = nullptr;
-    auto recursive = true;
+    auto recursive = FileIngestionMethod::Recursive;
     Hash expectedHash;
 
     for (auto & attr : *args[0]->attrs) {
@@ -1120,7 +1120,7 @@ static void prim_path(EvalState & state, const Pos & pos, Value * * args, Value
             state.forceValue(*attr.value);
             filterFun = attr.value;
         } else if (n == "recursive")
-            recursive = state.forceBool(*attr.value, *attr.pos);
+            recursive = FileIngestionMethod { state.forceBool(*attr.value, *attr.pos) };
         else if (n == "sha256")
             expectedHash = Hash(state.forceStringNoCtx(*attr.value, *attr.pos), htSHA256);
         else
diff --git a/src/libexpr/primops/fetchGit.cc b/src/libexpr/primops/fetchGit.cc
index 4aee1073e..9f2b673ad 100644
--- a/src/libexpr/primops/fetchGit.cc
+++ b/src/libexpr/primops/fetchGit.cc
@@ -69,7 +69,7 @@ GitInfo exportGit(ref<Store> store, const std::string & uri,
                 return files.count(file);
             };
 
-            gitInfo.storePath = store->printStorePath(store->addToStore("source", uri, true, htSHA256, filter));
+            gitInfo.storePath = store->printStorePath(store->addToStore("source", uri, FileIngestionMethod::Recursive, htSHA256, filter));
 
             return gitInfo;
         }
diff --git a/src/libexpr/primops/fetchMercurial.cc b/src/libexpr/primops/fetchMercurial.cc
index db274fa4f..548f4e392 100644
--- a/src/libexpr/primops/fetchMercurial.cc
+++ b/src/libexpr/primops/fetchMercurial.cc
@@ -63,7 +63,7 @@ HgInfo exportMercurial(ref<Store> store, const std::string & uri,
                 return files.count(file);
             };
 
-            hgInfo.storePath = store->printStorePath(store->addToStore("source", uri, true, htSHA256, filter));
+            hgInfo.storePath = store->printStorePath(store->addToStore("source", uri, FileIngestionMethod::Recursive, htSHA256, filter));
 
             return hgInfo;
         }
diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc
index 3a2d84861..a61af4a00 100644
--- a/src/libstore/binary-cache-store.cc
+++ b/src/libstore/binary-cache-store.cc
@@ -327,7 +327,7 @@ void BinaryCacheStore::queryPathInfoUncached(const StorePath & storePath,
 }
 
 StorePath BinaryCacheStore::addToStore(const string & name, const Path & srcPath,
-    bool recursive, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
+    FileIngestionMethod recursive, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
 {
     // FIXME: some cut&paste from LocalStore::addToStore().
 
@@ -336,7 +336,7 @@ StorePath BinaryCacheStore::addToStore(const string & name, const Path & srcPath
        small files. */
     StringSink sink;
     Hash h;
-    if (recursive) {
+    if (recursive == FileIngestionMethod::Recursive) {
         dumpPath(srcPath, sink, filter);
         h = hashString(hashAlgo, *sink.s);
     } else {
diff --git a/src/libstore/binary-cache-store.hh b/src/libstore/binary-cache-store.hh
index aa13c1cb4..1a1ea636c 100644
--- a/src/libstore/binary-cache-store.hh
+++ b/src/libstore/binary-cache-store.hh
@@ -79,7 +79,7 @@ public:
         std::shared_ptr<FSAccessor> accessor) override;
 
     StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive, HashType hashAlgo,
+        FileIngestionMethod recursive, HashType hashAlgo,
         PathFilter & filter, RepairFlag repair) override;
 
     StorePath addTextToStore(const string & name, const string & s,
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 0e3a23a4d..224633106 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -2712,7 +2712,7 @@ struct RestrictedStore : public LocalFSStore
     { throw Error("queryPathFromHashPart"); }
 
     StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive = true, HashType hashAlgo = htSHA256,
+        FileIngestionMethod recursive = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256,
         PathFilter & filter = defaultPathFilter, RepairFlag repair = NoRepair) override
     { throw Error("addToStore"); }
 
@@ -2725,7 +2725,7 @@ struct RestrictedStore : public LocalFSStore
     }
 
     StorePath addToStoreFromDump(const string & dump, const string & name,
-        bool recursive = true, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair) override
+        FileIngestionMethod recursive = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair) override
     {
         auto path = next->addToStoreFromDump(dump, name, recursive, hashAlgo, repair);
         goal.addDependency(path);
@@ -3647,10 +3647,10 @@ void DerivationGoal::registerOutputs()
 
         if (fixedOutput) {
 
-            bool recursive; Hash h;
+            FileIngestionMethod recursive; Hash h;
             i.second.parseHashInfo(recursive, h);
 
-            if (!recursive) {
+            if (!static_cast<bool>(recursive)) {
                 /* The output path should be a regular file without execute permission. */
                 if (!S_ISREG(st.st_mode) || (st.st_mode & S_IXUSR) != 0)
                     throw BuildError(
@@ -3659,7 +3659,7 @@ void DerivationGoal::registerOutputs()
 
             /* Check the hash. In hash mode, move the path produced by
                the derivation to its content-addressed location. */
-            Hash h2 = recursive ? hashPath(h.type, actualPath).first : hashFile(h.type, actualPath);
+            Hash h2 = static_cast<bool>(recursive) ? hashPath(h.type, actualPath).first : hashFile(h.type, actualPath);
 
             auto dest = worker.store.makeFixedOutputPath(recursive, h2, i.second.path.name());
 
@@ -3912,7 +3912,7 @@ void DerivationGoal::checkOutputs(const std::map<Path, ValidPathInfo> & outputs)
 
                 auto spec = parseReferenceSpecifiers(worker.store, *drv, *value);
 
-                auto used = recursive ? cloneStorePathSet(getClosure(info.path).first) : cloneStorePathSet(info.references);
+                auto used = static_cast<bool>(recursive) ? cloneStorePathSet(getClosure(info.path).first) : cloneStorePathSet(info.references);
 
                 if (recursive && checks.ignoreSelfRefs)
                     used.erase(info.path);
diff --git a/src/libstore/daemon.cc b/src/libstore/daemon.cc
index 8e9f9d71b..f1afdff69 100644
--- a/src/libstore/daemon.cc
+++ b/src/libstore/daemon.cc
@@ -355,20 +355,24 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case wopAddToStore: {
-        bool fixed, recursive;
         std::string s, baseName;
-        from >> baseName >> fixed /* obsolete */ >> recursive >> s;
-        /* Compatibility hack. */
-        if (!fixed) {
-            s = "sha256";
-            recursive = true;
+        FileIngestionMethod method;
+        {
+            bool fixed, recursive;
+            from >> baseName >> fixed /* obsolete */ >> recursive >> s;
+            method = FileIngestionMethod { recursive };
+            /* Compatibility hack. */
+            if (!fixed) {
+                s = "sha256";
+                method = FileIngestionMethod::Recursive;
+            }
         }
         HashType hashAlgo = parseHashType(s);
 
         TeeSource savedNAR(from);
         RetrieveRegularNARSink savedRegular;
 
-        if (recursive) {
+        if (method == FileIngestionMethod::Recursive) {
             /* Get the entire NAR dump from the client and save it to
                a string so that we can pass it to
                addToStoreFromDump(). */
@@ -380,7 +384,11 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         logger->startWork();
         if (!savedRegular.regular) throw Error("regular file expected");
 
-        auto path = store->addToStoreFromDump(recursive ? *savedNAR.data : savedRegular.s, baseName, recursive, hashAlgo);
+        auto path = store->addToStoreFromDump(
+            method == FileIngestionMethod::Recursive ? *savedNAR.data : savedRegular.s,
+            baseName,
+            method,
+            hashAlgo);
         logger->stopWork();
 
         to << store->printStorePath(path);
diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc
index 973ddc86a..5934c1912 100644
--- a/src/libstore/derivations.cc
+++ b/src/libstore/derivations.cc
@@ -9,13 +9,13 @@
 namespace nix {
 
 
-void DerivationOutput::parseHashInfo(bool & recursive, Hash & hash) const
+void DerivationOutput::parseHashInfo(FileIngestionMethod & recursive, Hash & hash) const
 {
-    recursive = false;
+    recursive = FileIngestionMethod::Flat;
     string algo = hashAlgo;
 
     if (string(algo, 0, 2) == "r:") {
-        recursive = true;
+        recursive = FileIngestionMethod::Recursive;
         algo = string(algo, 2);
     }
 
diff --git a/src/libstore/derivations.hh b/src/libstore/derivations.hh
index 7222d25e5..b1224b93b 100644
--- a/src/libstore/derivations.hh
+++ b/src/libstore/derivations.hh
@@ -22,7 +22,7 @@ struct DerivationOutput
         , hashAlgo(std::move(hashAlgo))
         , hash(std::move(hash))
     { }
-    void parseHashInfo(bool & recursive, Hash & hash) const;
+    void parseHashInfo(FileIngestionMethod & recursive, Hash & hash) const;
 };
 
 typedef std::map<string, DerivationOutput> DerivationOutputs;
diff --git a/src/libstore/download.cc b/src/libstore/download.cc
index 149c84765..8a9b65899 100644
--- a/src/libstore/download.cc
+++ b/src/libstore/download.cc
@@ -814,7 +814,8 @@ CachedDownloadResult Downloader::downloadCached(
 
     std::optional<StorePath> expectedStorePath;
     if (request.expectedHash) {
-        expectedStorePath = store->makeFixedOutputPath(request.unpack, request.expectedHash, name);
+        auto method = request.unpack ? FileIngestionMethod::Recursive : FileIngestionMethod::Flat;
+        expectedStorePath = store->makeFixedOutputPath(method, request.expectedHash, name);
         if (store->isValidPath(*expectedStorePath)) {
             CachedDownloadResult result;
             result.storePath = store->printStorePath(*expectedStorePath);
@@ -875,10 +876,10 @@ CachedDownloadResult Downloader::downloadCached(
                 StringSink sink;
                 dumpString(*res.data, sink);
                 Hash hash = hashString(request.expectedHash ? request.expectedHash.type : htSHA256, *res.data);
-                ValidPathInfo info(store->makeFixedOutputPath(false, hash, name));
+                ValidPathInfo info(store->makeFixedOutputPath(FileIngestionMethod::Flat, hash, name));
                 info.narHash = hashString(htSHA256, *sink.s);
                 info.narSize = sink.s->size();
-                info.ca = makeFixedOutputCA(false, hash);
+                info.ca = makeFixedOutputCA(FileIngestionMethod::Flat, hash);
                 store->addToStore(info, sink.s, NoRepair, NoCheckSigs);
                 storePath = info.path.clone();
             }
@@ -914,7 +915,7 @@ CachedDownloadResult Downloader::downloadCached(
             if (members.size() != 1)
                 throw nix::Error("tarball '%s' contains an unexpected number of top-level files", url);
             auto topDir = tmpDir + "/" + members.begin()->name;
-            unpackedStorePath = store->addToStore(name, topDir, true, htSHA256, defaultPathFilter, NoRepair);
+            unpackedStorePath = store->addToStore(name, topDir, FileIngestionMethod::Recursive, htSHA256, defaultPathFilter, NoRepair);
         }
         replaceSymlink(store->printStorePath(*unpackedStorePath), unpackedLink);
         storePath = std::move(*unpackedStorePath);
diff --git a/src/libstore/legacy-ssh-store.cc b/src/libstore/legacy-ssh-store.cc
index 458266be0..af20d389b 100644
--- a/src/libstore/legacy-ssh-store.cc
+++ b/src/libstore/legacy-ssh-store.cc
@@ -195,7 +195,7 @@ struct LegacySSHStore : public Store
     { unsupported("queryPathFromHashPart"); }
 
     StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive, HashType hashAlgo,
+        FileIngestionMethod method, HashType hashAlgo,
         PathFilter & filter, RepairFlag repair) override
     { unsupported("addToStore"); }
 
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index ae7513ad8..746f81beb 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -557,7 +557,7 @@ void LocalStore::checkDerivationOutputs(const StorePath & drvPath, const Derivat
         if (out == drv.outputs.end())
             throw Error("derivation '%s' does not have an output named 'out'", printStorePath(drvPath));
 
-        bool recursive; Hash h;
+        FileIngestionMethod recursive; Hash h;
         out->second.parseHashInfo(recursive, h);
 
         check(makeFixedOutputPath(recursive, h, drvName), out->second.path, "out");
@@ -1043,7 +1043,7 @@ void LocalStore::addToStore(const ValidPathInfo & info, Source & source,
 
 
 StorePath LocalStore::addToStoreFromDump(const string & dump, const string & name,
-    bool recursive, HashType hashAlgo, RepairFlag repair)
+    FileIngestionMethod recursive, HashType hashAlgo, RepairFlag repair)
 {
     Hash h = hashString(hashAlgo, dump);
 
@@ -1067,7 +1067,7 @@ StorePath LocalStore::addToStoreFromDump(const string & dump, const string & nam
 
             autoGC();
 
-            if (recursive) {
+            if (recursive == FileIngestionMethod::Recursive) {
                 StringSource source(dump);
                 restorePath(realPath, source);
             } else
@@ -1080,7 +1080,7 @@ StorePath LocalStore::addToStoreFromDump(const string & dump, const string & nam
                above (if called with recursive == true and hashAlgo ==
                sha256); otherwise, compute it here. */
             HashResult hash;
-            if (recursive) {
+            if (recursive == FileIngestionMethod::Recursive) {
                 hash.first = hashAlgo == htSHA256 ? h : hashString(htSHA256, dump);
                 hash.second = dump.size();
             } else
@@ -1103,7 +1103,7 @@ StorePath LocalStore::addToStoreFromDump(const string & dump, const string & nam
 
 
 StorePath LocalStore::addToStore(const string & name, const Path & _srcPath,
-    bool recursive, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
+    FileIngestionMethod recursive, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
 {
     Path srcPath(absPath(_srcPath));
 
@@ -1111,7 +1111,7 @@ StorePath LocalStore::addToStore(const string & name, const Path & _srcPath,
        method for very large paths, but `copyPath' is mainly used for
        small files. */
     StringSink sink;
-    if (recursive)
+    if (recursive == FileIngestionMethod::Recursive)
         dumpPath(srcPath, sink, filter);
     else
         sink.s = make_ref<std::string>(readFile(srcPath));
diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh
index 16aeab0ad..c1e75390c 100644
--- a/src/libstore/local-store.hh
+++ b/src/libstore/local-store.hh
@@ -149,7 +149,7 @@ public:
         std::shared_ptr<FSAccessor> accessor) override;
 
     StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive, HashType hashAlgo,
+        FileIngestionMethod method, HashType hashAlgo,
         PathFilter & filter, RepairFlag repair) override;
 
     /* Like addToStore(), but the contents of the path are contained
@@ -157,7 +157,7 @@ public:
        true) or simply the contents of a regular file (if recursive ==
        false). */
     StorePath addToStoreFromDump(const string & dump, const string & name,
-        bool recursive = true, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair) override;
+        FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair) override;
 
     StorePath addTextToStore(const string & name, const string & s,
         const StorePathSet & references, RepairFlag repair) override;
diff --git a/src/libstore/path.hh b/src/libstore/path.hh
index c90bb1fff..73c4b8e29 100644
--- a/src/libstore/path.hh
+++ b/src/libstore/path.hh
@@ -73,6 +73,11 @@ const size_t storePathHashLen = 32; // i.e. 160 bits
 /* Extension of derivations in the Nix store. */
 const std::string drvExtension = ".drv";
 
+enum struct FileIngestionMethod : bool {
+    Flat = false,
+    Recursive = true
+};
+
 struct StorePathWithOutputs
 {
     StorePath path;
diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc
index 8c55da268..5c36693e6 100644
--- a/src/libstore/remote-store.cc
+++ b/src/libstore/remote-store.cc
@@ -484,7 +484,7 @@ void RemoteStore::addToStore(const ValidPathInfo & info, Source & source,
 
 
 StorePath RemoteStore::addToStore(const string & name, const Path & _srcPath,
-    bool recursive, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
+    FileIngestionMethod method, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
 {
     if (repair) throw Error("repairing is not supported when building through the Nix daemon");
 
@@ -492,10 +492,12 @@ StorePath RemoteStore::addToStore(const string & name, const Path & _srcPath,
 
     Path srcPath(absPath(_srcPath));
 
-    conn->to << wopAddToStore << name
-       << ((hashAlgo == htSHA256 && recursive) ? 0 : 1) /* backwards compatibility hack */
-       << (recursive ? 1 : 0)
-       << printHashType(hashAlgo);
+    conn->to
+        << wopAddToStore
+        << name
+        << ((hashAlgo == htSHA256 && method == FileIngestionMethod::Recursive) ? 0 : 1) /* backwards compatibility hack */
+        << (method == FileIngestionMethod::Recursive ? 1 : 0)
+        << printHashType(hashAlgo);
 
     try {
         conn->to.written = 0;
diff --git a/src/libstore/remote-store.hh b/src/libstore/remote-store.hh
index f301a97d8..3c86b4524 100644
--- a/src/libstore/remote-store.hh
+++ b/src/libstore/remote-store.hh
@@ -65,7 +65,7 @@ public:
         std::shared_ptr<FSAccessor> accessor) override;
 
     StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive = true, HashType hashAlgo = htSHA256,
+        FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256,
         PathFilter & filter = defaultPathFilter, RepairFlag repair = NoRepair) override;
 
     StorePath addTextToStore(const string & name, const string & s,
diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index b9e894a9a..06aa0883c 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -171,18 +171,18 @@ static std::string makeType(
 
 
 StorePath Store::makeFixedOutputPath(
-    bool recursive,
+    FileIngestionMethod recursive,
     const Hash & hash,
     std::string_view name,
     const StorePathSet & references,
     bool hasSelfReference) const
 {
-    if (hash.type == htSHA256 && recursive) {
+    if (hash.type == htSHA256  && recursive == FileIngestionMethod::Recursive) {
         return makeStorePath(makeType(*this, "source", references, hasSelfReference), hash, name);
     } else {
         assert(references.empty());
         return makeStorePath("output:out", hashString(htSHA256,
-                "fixed:out:" + (recursive ? (string) "r:" : "") +
+                "fixed:out:" + (static_cast<bool>(recursive) ? (string) "r:" : "") +
                 hash.to_string(Base16) + ":"), name);
     }
 }
@@ -200,9 +200,9 @@ StorePath Store::makeTextPath(std::string_view name, const Hash & hash,
 
 
 std::pair<StorePath, Hash> Store::computeStorePathForPath(std::string_view name,
-    const Path & srcPath, bool recursive, HashType hashAlgo, PathFilter & filter) const
+    const Path & srcPath, FileIngestionMethod recursive, HashType hashAlgo, PathFilter & filter) const
 {
-    Hash h = recursive ? hashPath(hashAlgo, srcPath, filter).first : hashFile(hashAlgo, srcPath);
+    Hash h = static_cast<bool>(recursive) ? hashPath(hashAlgo, srcPath, filter).first : hashFile(hashAlgo, srcPath);
     return std::make_pair(makeFixedOutputPath(recursive, h, name), h);
 }
 
@@ -781,8 +781,8 @@ bool ValidPathInfo::isContentAddressed(const Store & store) const
     }
 
     else if (hasPrefix(ca, "fixed:")) {
-        bool recursive = ca.compare(6, 2, "r:") == 0;
-        Hash hash(std::string(ca, recursive ? 8 : 6));
+        FileIngestionMethod recursive { ca.compare(6, 2, "r:") == 0 };
+        Hash hash(std::string(ca, static_cast<bool>(recursive) ? 8 : 6));
         auto refs = cloneStorePathSet(references);
         bool hasSelfReference = false;
         if (refs.count(path)) {
@@ -826,9 +826,9 @@ Strings ValidPathInfo::shortRefs() const
 }
 
 
-std::string makeFixedOutputCA(bool recursive, const Hash & hash)
+std::string makeFixedOutputCA(FileIngestionMethod recursive, const Hash & hash)
 {
-    return "fixed:" + (recursive ? (std::string) "r:" : "") + hash.to_string();
+    return "fixed:" + (static_cast<bool>(recursive) ? (std::string) "r:" : "") + hash.to_string();
 }
 
 
diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index 0fa59be6a..32c24c500 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -43,7 +43,6 @@ enum CheckSigsFlag : bool { NoCheckSigs = false, CheckSigs = true };
 enum SubstituteFlag : bool { NoSubstitute = false, Substitute = true };
 enum AllowInvalidFlag : bool { DisallowInvalid = false, AllowInvalid = true };
 
-
 /* Magic header of exportPath() output (obsolete). */
 const uint32_t exportMagic = 0x4558494e;
 
@@ -346,7 +345,7 @@ public:
     StorePath makeOutputPath(const string & id,
         const Hash & hash, std::string_view name) const;
 
-    StorePath makeFixedOutputPath(bool recursive,
+    StorePath makeFixedOutputPath(FileIngestionMethod method,
         const Hash & hash, std::string_view name,
         const StorePathSet & references = {},
         bool hasSelfReference = false) const;
@@ -358,7 +357,7 @@ public:
        store path to which srcPath is to be copied.  Returns the store
        path and the cryptographic hash of the contents of srcPath. */
     std::pair<StorePath, Hash> computeStorePathForPath(std::string_view name,
-        const Path & srcPath, bool recursive = true,
+        const Path & srcPath, FileIngestionMethod method = FileIngestionMethod::Recursive,
         HashType hashAlgo = htSHA256, PathFilter & filter = defaultPathFilter) const;
 
     /* Preparatory part of addTextToStore().
@@ -462,12 +461,12 @@ public:
        The function object `filter' can be used to exclude files (see
        libutil/archive.hh). */
     virtual StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive = true, HashType hashAlgo = htSHA256,
+        FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256,
         PathFilter & filter = defaultPathFilter, RepairFlag repair = NoRepair) = 0;
 
     // FIXME: remove?
     virtual StorePath addToStoreFromDump(const string & dump, const string & name,
-        bool recursive = true, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair)
+        FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair)
     {
         throw Error("addToStoreFromDump() is not supported by this store");
     }
@@ -850,7 +849,7 @@ std::optional<ValidPathInfo> decodeValidPathInfo(
 
 /* Compute the content-addressability assertion (ValidPathInfo::ca)
    for paths created by makeFixedOutputPath() / addToStore(). */
-std::string makeFixedOutputCA(bool recursive, const Hash & hash);
+std::string makeFixedOutputCA(FileIngestionMethod method, const Hash & hash);
 
 
 /* Split URI into protocol+hierarchy part and its parameter set. */
diff --git a/src/nix-prefetch-url/nix-prefetch-url.cc b/src/nix-prefetch-url/nix-prefetch-url.cc
index 18ced94b1..8c364a86a 100644
--- a/src/nix-prefetch-url/nix-prefetch-url.cc
+++ b/src/nix-prefetch-url/nix-prefetch-url.cc
@@ -159,7 +159,8 @@ static int _main(int argc, char * * argv)
         std::optional<StorePath> storePath;
         if (args.size() == 2) {
             expectedHash = Hash(args[1], ht);
-            storePath = store->makeFixedOutputPath(unpack, expectedHash, name);
+            const auto recursive = unpack ? FileIngestionMethod::Recursive : FileIngestionMethod::Flat;
+            storePath = store->makeFixedOutputPath(recursive, expectedHash, name);
             if (store->isValidPath(*storePath))
                 hash = expectedHash;
             else
@@ -208,13 +209,15 @@ static int _main(int argc, char * * argv)
             if (expectedHash != Hash(ht) && expectedHash != hash)
                 throw Error(format("hash mismatch for '%1%'") % uri);
 
+            const auto recursive = unpack ? FileIngestionMethod::Recursive : FileIngestionMethod::Flat;
+
             /* Copy the file to the Nix store. FIXME: if RemoteStore
                implemented addToStoreFromDump() and downloadFile()
                supported a sink, we could stream the download directly
                into the Nix store. */
-            storePath = store->addToStore(name, tmpFile, unpack, ht);
+            storePath = store->addToStore(name, tmpFile, recursive, ht);
 
-            assert(*storePath == store->makeFixedOutputPath(unpack, hash, name));
+            assert(*storePath == store->makeFixedOutputPath(recursive, hash, name));
         }
 
         stopProgressBar();
diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc
index 806ab7563..9a26eb57f 100644
--- a/src/nix-store/nix-store.cc
+++ b/src/nix-store/nix-store.cc
@@ -174,10 +174,10 @@ static void opAdd(Strings opFlags, Strings opArgs)
    store. */
 static void opAddFixed(Strings opFlags, Strings opArgs)
 {
-    bool recursive = false;
+    FileIngestionMethod recursive = FileIngestionMethod::Flat;
 
     for (auto & i : opFlags)
-        if (i == "--recursive") recursive = true;
+        if (i == "--recursive") recursive = FileIngestionMethod::Recursive;
         else throw UsageError(format("unknown flag '%1%'") % i);
 
     if (opArgs.empty())
@@ -194,10 +194,10 @@ static void opAddFixed(Strings opFlags, Strings opArgs)
 /* Hack to support caching in `nix-prefetch-url'. */
 static void opPrintFixedPath(Strings opFlags, Strings opArgs)
 {
-    bool recursive = false;
+    FileIngestionMethod recursive = FileIngestionMethod::Flat;
 
     for (auto i : opFlags)
-        if (i == "--recursive") recursive = true;
+        if (i == "--recursive") recursive = FileIngestionMethod::Recursive;
         else throw UsageError(format("unknown flag '%1%'") % i);
 
     if (opArgs.size() != 3)
diff --git a/src/nix/add-to-store.cc b/src/nix/add-to-store.cc
index 139db3657..e82ab844e 100644
--- a/src/nix/add-to-store.cc
+++ b/src/nix/add-to-store.cc
@@ -42,10 +42,10 @@ struct CmdAddToStore : MixDryRun, StoreCommand
 
         auto narHash = hashString(htSHA256, *sink.s);
 
-        ValidPathInfo info(store->makeFixedOutputPath(true, narHash, *namePart));
+        ValidPathInfo info(store->makeFixedOutputPath(FileIngestionMethod::Recursive, narHash, *namePart));
         info.narHash = narHash;
         info.narSize = sink.s->size();
-        info.ca = makeFixedOutputCA(true, info.narHash);
+        info.ca = makeFixedOutputCA(FileIngestionMethod::Recursive, info.narHash);
 
         if (!dryRun)
             store->addToStore(info, sink.s);
diff --git a/src/nix/command.cc b/src/nix/command.cc
index 442bc6c53..fce6c391c 100644
--- a/src/nix/command.cc
+++ b/src/nix/command.cc
@@ -28,20 +28,20 @@ void StoreCommand::run()
     run(getStore());
 }
 
-StorePathsCommand::StorePathsCommand(bool recursive)
+StorePathsCommand::StorePathsCommand(FileIngestionMethod recursive)
     : recursive(recursive)
 {
-    if (recursive)
+    if (recursive == FileIngestionMethod::Recursive)
         mkFlag()
             .longName("no-recursive")
             .description("apply operation to specified paths only")
-            .set(&this->recursive, false);
+            .set(&this->recursive, FileIngestionMethod::Flat);
     else
         mkFlag()
             .longName("recursive")
             .shortName('r')
             .description("apply operation to closure of the specified paths")
-            .set(&this->recursive, true);
+            .set(&this->recursive, FileIngestionMethod::Recursive);
 
     mkFlag(0, "all", "apply operation to the entire store", &all);
 }
@@ -61,7 +61,7 @@ void StorePathsCommand::run(ref<Store> store)
         for (auto & p : toStorePaths(store, realiseMode, installables))
             storePaths.push_back(p.clone());
 
-        if (recursive) {
+        if (recursive == FileIngestionMethod::Recursive) {
             StorePathSet closure;
             store->computeFSClosure(storePathsToSet(storePaths), closure, false, false);
             storePaths.clear();
diff --git a/src/nix/command.hh b/src/nix/command.hh
index a954a7d04..4cdda9f79 100644
--- a/src/nix/command.hh
+++ b/src/nix/command.hh
@@ -114,7 +114,7 @@ struct StorePathsCommand : public InstallablesCommand
 {
 private:
 
-    bool recursive = false;
+    FileIngestionMethod recursive = FileIngestionMethod::Flat;
     bool all = false;
 
 protected:
@@ -123,7 +123,7 @@ protected:
 
 public:
 
-    StorePathsCommand(bool recursive = false);
+    StorePathsCommand(FileIngestionMethod recursive = FileIngestionMethod::Flat);
 
     using StoreCommand::run;
 
diff --git a/src/nix/copy.cc b/src/nix/copy.cc
index 85c777d38..a8ee3fce3 100644
--- a/src/nix/copy.cc
+++ b/src/nix/copy.cc
@@ -17,7 +17,7 @@ struct CmdCopy : StorePathsCommand
     SubstituteFlag substitute = NoSubstitute;
 
     CmdCopy()
-        : StorePathsCommand(true)
+        : StorePathsCommand(FileIngestionMethod::Recursive)
     {
         mkFlag()
             .longName("from")
diff --git a/src/nix/make-content-addressable.cc b/src/nix/make-content-addressable.cc
index f9c7fef3f..93eddbb1f 100644
--- a/src/nix/make-content-addressable.cc
+++ b/src/nix/make-content-addressable.cc
@@ -74,12 +74,12 @@ struct CmdMakeContentAddressable : StorePathsCommand, MixJSON
 
             auto narHash = hashModuloSink.finish().first;
 
-            ValidPathInfo info(store->makeFixedOutputPath(true, narHash, path.name(), references, hasSelfReference));
+            ValidPathInfo info(store->makeFixedOutputPath(FileIngestionMethod::Recursive, narHash, path.name(), references, hasSelfReference));
             info.references = std::move(references);
             if (hasSelfReference) info.references.insert(info.path.clone());
             info.narHash = narHash;
             info.narSize = sink.s->size();
-            info.ca = makeFixedOutputCA(true, info.narHash);
+            info.ca = makeFixedOutputCA(FileIngestionMethod::Recursive, info.narHash);
 
             if (!json)
                 printError("rewrote '%s' to '%s'", pathS, store->printStorePath(info.path));