nix-store -r: Handle symlinks to store paths

Fixes #3270.

src/libexpr/get-drvs.cc

@@ -19,7 +19,7 @@ DrvInfo::DrvInfo(EvalState & state, const string & attrPath, Bindings * attrs)
 DrvInfo::DrvInfo(EvalState & state, ref<Store> store, const std::string & drvPathWithOutputs)
     : state(&state), attrs(nullptr), attrPath("")
 {
-    auto [drvPath, selectedOutputs] = store->parseDrvPathWithOutputs(drvPathWithOutputs);
+    auto [drvPath, selectedOutputs] = store->parsePathWithOutputs(drvPathWithOutputs);
 
     this->drvPath = store->printStorePath(drvPath);
 

src/libstore/daemon.cc

@@ -424,7 +424,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     case wopBuildPaths: {
         std::vector<StorePathWithOutputs> drvs;
         for (auto & s : readStrings<Strings>(from))
-            drvs.push_back(store->parseDrvPathWithOutputs(s));
+            drvs.push_back(store->parsePathWithOutputs(s));
         BuildMode mode = bmNormal;
         if (GET_PROTOCOL_MINOR(clientVersion) >= 15) {
             mode = (BuildMode) readInt(from);
@@ -721,7 +721,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     case wopQueryMissing: {
         std::vector<StorePathWithOutputs> targets;
         for (auto & s : readStrings<Strings>(from))
-            targets.push_back(store->parseDrvPathWithOutputs(s));
+            targets.push_back(store->parsePathWithOutputs(s));
         logger->startWork();
         StorePathSet willBuild, willSubstitute, unknown;
         unsigned long long downloadSize, narSize;

src/libstore/derivations.cc

@@ -375,16 +375,6 @@ Hash hashDerivationModulo(Store & store, const Derivation & drv, bool maskOutput
 }
 
 
-StorePathWithOutputs Store::parseDrvPathWithOutputs(const std::string & s)
-{
-    size_t n = s.find("!");
-    return n == s.npos
-        ? StorePathWithOutputs{parseStorePath(s), std::set<string>()}
-        : StorePathWithOutputs{parseStorePath(std::string_view(s.data(), n)),
-            tokenizeString<std::set<string>>(string(s, n + 1), ",")};
-}
-
-
 std::string StorePathWithOutputs::to_string(const Store & store) const
 {
     return outputs.empty()

src/libstore/path.cc

@@ -96,4 +96,19 @@ StorePathSet singleton(const StorePath & path)
     return res;
 }
 
+std::pair<std::string_view, StringSet> parsePathWithOutputs(std::string_view s)
+{
+    size_t n = s.find("!");
+    return n == s.npos
+        ? std::make_pair(s, std::set<string>())
+        : std::make_pair(((std::string_view) s).substr(0, n),
+            tokenizeString<std::set<string>>(((std::string_view) s).substr(n + 1), ","));
+}
+
+StorePathWithOutputs Store::parsePathWithOutputs(const std::string & s)
+{
+    auto [path, outputs] = nix::parsePathWithOutputs(s);
+    return {parseStorePath(path), std::move(outputs)};
+}
+
 }

src/libstore/path.hh

@@ -7,6 +7,8 @@ namespace nix {
 /* See path.rs. */
 struct StorePath;
 
+struct Store;
+
 extern "C" {
     void ffi_StorePath_drop(void *);
     bool ffi_StorePath_less_than(const StorePath & a, const StorePath & b);
@@ -67,6 +69,28 @@ const size_t storePathHashLen = 32; // i.e. 160 bits
 /* Extension of derivations in the Nix store. */
 const std::string drvExtension = ".drv";
 
+struct StorePathWithOutputs
+{
+    StorePath path;
+    std::set<std::string> outputs;
+
+    StorePathWithOutputs(const StorePath & path, const std::set<std::string> & outputs = {})
+        : path(path.clone()), outputs(outputs)
+    { }
+
+    StorePathWithOutputs(StorePath && path, std::set<std::string> && outputs)
+        : path(std::move(path)), outputs(std::move(outputs))
+    { }
+
+    StorePathWithOutputs(const StorePathWithOutputs & other)
+        : path(other.path.clone()), outputs(other.outputs)
+    { }
+
+    std::string to_string(const Store & store) const;
+};
+
+std::pair<std::string_view, StringSet> parsePathWithOutputs(std::string_view s);
+
 }
 
 namespace std {

src/libstore/store-api.cc

@@ -39,9 +39,9 @@ Path Store::toStorePath(const Path & path) const
 }
 
 
-Path Store::followLinksToStore(const Path & _path) const
+Path Store::followLinksToStore(std::string_view _path) const
 {
-    Path path = absPath(_path);
+    Path path = absPath(std::string(_path));
     while (!isInStore(path)) {
         if (!isLink(path)) break;
         string target = readLink(path);
@@ -53,12 +53,19 @@ Path Store::followLinksToStore(const Path & _path) const
 }
 
 
-StorePath Store::followLinksToStorePath(const Path & path) const
+StorePath Store::followLinksToStorePath(std::string_view path) const
 {
     return parseStorePath(toStorePath(followLinksToStore(path)));
 }
 
 
+StorePathWithOutputs Store::followLinksToStorePathWithOutputs(std::string_view path) const
+{
+    auto [path2, outputs] = nix::parsePathWithOutputs(path);
+    return StorePathWithOutputs(followLinksToStorePath(path2), std::move(outputs));
+}
+
+
 string storePathToHash(const Path & path)
 {
     auto base = baseNameOf(path);

src/libstore/store-api.hh

@@ -241,23 +241,6 @@ struct BuildResult
 };
 
 
-struct StorePathWithOutputs
-{
-    StorePath path;
-    std::set<std::string> outputs;
-
-    StorePathWithOutputs(const StorePath & path, const std::set<std::string> & outputs = {})
-        : path(path.clone()), outputs(outputs)
-    { }
-
-    StorePathWithOutputs(const StorePathWithOutputs & other)
-        : path(other.path.clone()), outputs(other.outputs)
-    { }
-
-    std::string to_string(const Store & store) const;
-};
-
-
 class Store : public std::enable_shared_from_this<Store>, public Config
 {
 public:
@@ -304,7 +287,7 @@ public:
     /* Split a string specifying a derivation and a set of outputs
        (/nix/store/hash-foo!out1,out2,...) into the derivation path
        and the outputs. */
-    StorePathWithOutputs parseDrvPathWithOutputs(const string & s);
+    StorePathWithOutputs parsePathWithOutputs(const string & s);
 
     /* Display a set of paths in human-readable form (i.e., between quotes
        and separated by commas). */
@@ -323,11 +306,13 @@ public:
     Path toStorePath(const Path & path) const;
 
     /* Follow symlinks until we end up with a path in the Nix store. */
-    Path followLinksToStore(const Path & path) const;
+    Path followLinksToStore(std::string_view path) const;
 
     /* Same as followLinksToStore(), but apply toStorePath() to the
        result. */
-    StorePath followLinksToStorePath(const Path & path) const;
+    StorePath followLinksToStorePath(std::string_view path) const;
+
+    StorePathWithOutputs followLinksToStorePathWithOutputs(std::string_view path) const;
 
     /* Constructs a unique store path name. */
     StorePath makeStorePath(const string & type,

src/libutil/util.cc

@@ -1186,7 +1186,7 @@ void _interrupted()
 //////////////////////////////////////////////////////////////////////
 
 
-template<class C> C tokenizeString(const string & s, const string & separators)
+template<class C> C tokenizeString(std::string_view s, const string & separators)
 {
     C result;
     string::size_type pos = s.find_first_not_of(separators, 0);
@@ -1200,9 +1200,9 @@ template<class C> C tokenizeString(const string & s, const string & separators)
     return result;
 }
 
-template Strings tokenizeString(const string & s, const string & separators);
-template StringSet tokenizeString(const string & s, const string & separators);
-template vector<string> tokenizeString(const string & s, const string & separators);
+template Strings tokenizeString(std::string_view s, const string & separators);
+template StringSet tokenizeString(std::string_view s, const string & separators);
+template vector<string> tokenizeString(std::string_view s, const string & separators);
 
 
 string concatStringsSep(const string & sep, const Strings & ss)

src/libutil/util.hh

@@ -340,7 +340,7 @@ MakeError(FormatError, Error);
 
 
 /* String tokenizer. */
-template<class C> C tokenizeString(const string & s, const string & separators = " \t\n\r");
+template<class C> C tokenizeString(std::string_view s, const string & separators = " \t\n\r");
 
 
 /* Concatenate the given strings with a separator between the

src/nix-store/nix-store.cc

@@ -128,7 +128,7 @@ static void opRealise(Strings opFlags, Strings opArgs)
 
     std::vector<StorePathWithOutputs> paths;
     for (auto & i : opArgs)
-        paths.push_back(store->parseDrvPathWithOutputs(i));
+        paths.push_back(store->followLinksToStorePathWithOutputs(i));
 
     unsigned long long downloadSize, narSize;
     StorePathSet willBuild, willSubstitute, unknown;
@@ -893,7 +893,7 @@ static void opServe(Strings opFlags, Strings opArgs)
 
                 std::vector<StorePathWithOutputs> paths;
                 for (auto & s : readStrings<Strings>(in))
-                    paths.emplace_back(store->parseDrvPathWithOutputs(s));
+                    paths.emplace_back(store->parsePathWithOutputs(s));
 
                 getBuildSettings();
 

tests/nix-build.sh

@@ -23,3 +23,6 @@ outPath2=$(nix-build $(nix-instantiate dependencies.nix) --no-out-link)
 
 outPath2=$(nix-build $(nix-instantiate dependencies.nix)!out --no-out-link)
 [[ $outPath = $outPath2 ]]
+
+outPath2=$(nix-store -r $(nix-instantiate --indirect --add-root $TEST_ROOT/indirect dependencies.nix)!out)
+[[ $outPath = $outPath2 ]]