refactor(3p/nix): Make all single-argument constructors explicit r/778

Implicit constructors can be confusing, especially in a codebase that
is already as unintentionally obfuscated as this one.

https://google.github.io/styleguide/cppguide.html#Explicit_Constructors

12 files changed, 31 insertions, 31 deletions

diff --git a/third_party/nix/src/libstore/build.cc b/third_party/nix/src/libstore/build.cc
index b1f63a4fac..3349e1e8c8 100644
--- a/third_party/nix/src/libstore/build.cc
+++ b/third_party/nix/src/libstore/build.cc
@@ -133,7 +133,7 @@ class Goal : public std::enable_shared_from_this<Goal> {
   /* Whether the goal is finished. */
   ExitCode exitCode;
 
-  Goal(Worker& worker) : worker(worker) {
+  explicit Goal(Worker& worker) : worker(worker) {
     nrFailed = nrNoSubstituters = nrIncompleteClosure = 0;
     exitCode = ecBusy;
   }
@@ -264,7 +264,7 @@ class Worker {
      it answers with "decline-permanently", we don't try again. */
   bool tryBuildHook = true;
 
-  Worker(LocalStore& store);
+  explicit Worker(LocalStore& store);
   ~Worker();
 
   /* Make a goal (with caching). */
@@ -823,7 +823,7 @@ class DerivationGoal : public Goal {
   struct ChrootPath {
     Path source;
     bool optional;
-    ChrootPath(Path source = "", bool optional = false)
+    explicit ChrootPath(Path source = "", bool optional = false)
         : source(source), optional(optional) {}
   };
   typedef map<Path, ChrootPath>
@@ -2037,12 +2037,12 @@ void DerivationGoal::startBuilder() {
       }
       size_t p = i.find('=');
       if (p == string::npos) {
-        dirsInChroot[i] = {i, optional};
+        dirsInChroot[i] = ChrootPath(i, optional);
       } else {
-        dirsInChroot[string(i, 0, p)] = {string(i, p + 1), optional};
+        dirsInChroot[string(i, 0, p)] = ChrootPath(string(i, p + 1), optional);
       }
     }
-    dirsInChroot[tmpDirInSandbox] = tmpDir;
+    dirsInChroot[tmpDirInSandbox] = ChrootPath(tmpDir);
 
     /* Add the closure of store paths to the chroot. */
     PathSet closure;
@@ -2058,7 +2058,7 @@ void DerivationGoal::startBuilder() {
       }
     }
     for (auto& i : closure) {
-      dirsInChroot[i] = i;
+      dirsInChroot[i] = ChrootPath(i);
     }
 
     PathSet allowedPaths = settings.allowedImpureHostPrefixes;
@@ -2088,7 +2088,7 @@ void DerivationGoal::startBuilder() {
                     drvPath % i);
       }
 
-      dirsInChroot[i] = i;
+      dirsInChroot[i] = ChrootPath(i);
     }
 
 #if __linux__
@@ -2170,7 +2170,7 @@ void DerivationGoal::startBuilder() {
         throw SysError(format("getting attributes of path '%1%'") % i);
       }
       if (S_ISDIR(st.st_mode)) {
-        dirsInChroot[i] = r;
+        dirsInChroot[i] = ChrootPath(r);
       } else {
         Path p = chrootRootDir + i;
         DLOG(INFO) << "linking '" << p << "' to '" << r << "'";
@@ -2264,9 +2264,9 @@ void DerivationGoal::startBuilder() {
         } else {
           auto p = line.find('=');
           if (p == string::npos) {
-            dirsInChroot[line] = line;
+            dirsInChroot[line] = ChrootPath(line);
           } else {
-            dirsInChroot[string(line, 0, p)] = string(line, p + 1);
+            dirsInChroot[string(line, 0, p)] = ChrootPath(string(line, p + 1));
           }
         }
       }
diff --git a/third_party/nix/src/libstore/export-import.cc b/third_party/nix/src/libstore/export-import.cc
index 6a1862492d..d50638d5b0 100644
--- a/third_party/nix/src/libstore/export-import.cc
+++ b/third_party/nix/src/libstore/export-import.cc
@@ -9,7 +9,7 @@ namespace nix {
 struct HashAndWriteSink : Sink {
   Sink& writeSink;
   HashSink hashSink;
-  HashAndWriteSink(Sink& writeSink)
+  explicit HashAndWriteSink(Sink& writeSink)
       : writeSink(writeSink), hashSink(htSHA256) {}
   virtual void operator()(const unsigned char* data, size_t len) {
     writeSink(data, len);
diff --git a/third_party/nix/src/libstore/gc.cc b/third_party/nix/src/libstore/gc.cc
index 3e79e6c336..2241c58c41 100644
--- a/third_party/nix/src/libstore/gc.cc
+++ b/third_party/nix/src/libstore/gc.cc
@@ -505,7 +505,7 @@ struct LocalStore::GCState {
   unsigned long long bytesInvalidated;
   bool moveToTrash = true;
   bool shouldDelete;
-  GCState(GCResults& results_) : results(results_), bytesInvalidated(0) {}
+  explicit GCState(GCResults& results_) : results(results_), bytesInvalidated(0) {}
 };
 
 bool LocalStore::isActiveTempFile(const GCState& state, const Path& path,
diff --git a/third_party/nix/src/libstore/local-fs-store.cc b/third_party/nix/src/libstore/local-fs-store.cc
index bc282eac96..f3ac5b3663 100644
--- a/third_party/nix/src/libstore/local-fs-store.cc
+++ b/third_party/nix/src/libstore/local-fs-store.cc
@@ -12,7 +12,7 @@ LocalFSStore::LocalFSStore(const Params& params) : Store(params) {}
 struct LocalStoreAccessor : public FSAccessor {
   ref<LocalFSStore> store;
 
-  LocalStoreAccessor(ref<LocalFSStore> store) : store(store) {}
+  explicit LocalStoreAccessor(ref<LocalFSStore> store) : store(store) {}
 
   Path toRealPath(const Path& path) {
     Path storePath = store->toStorePath(path);
diff --git a/third_party/nix/src/libstore/misc.cc b/third_party/nix/src/libstore/misc.cc
index a82fc1251c..0ef0e55987 100644
--- a/third_party/nix/src/libstore/misc.cc
+++ b/third_party/nix/src/libstore/misc.cc
@@ -151,7 +151,7 @@ void Store::queryMissing(const PathSet& targets, PathSet& willBuild_,
     size_t left;
     bool done = false;
     PathSet outPaths;
-    DrvState(size_t left) : left(left) {}
+    explicit DrvState(size_t left) : left(left) {}
   };
 
   Sync<State> state_(State{PathSet(), unknown_, willSubstitute_, willBuild_,
diff --git a/third_party/nix/src/libstore/nar-accessor.cc b/third_party/nix/src/libstore/nar-accessor.cc
index 8be22ada2e..ffbf7c1a89 100644
--- a/third_party/nix/src/libstore/nar-accessor.cc
+++ b/third_party/nix/src/libstore/nar-accessor.cc
@@ -93,7 +93,7 @@ struct NarAccessor : public FSAccessor {
     }
   };
 
-  NarAccessor(ref<const std::string> nar) : nar(nar) {
+  explicit NarAccessor(ref<const std::string> nar) : nar(nar) {
     NarIndexer indexer(*this, *nar);
     parseDump(indexer, indexer);
   }
diff --git a/third_party/nix/src/libstore/optimise-store.cc b/third_party/nix/src/libstore/optimise-store.cc
index 8c0f24d382..7febe1b145 100644
--- a/third_party/nix/src/libstore/optimise-store.cc
+++ b/third_party/nix/src/libstore/optimise-store.cc
@@ -27,7 +27,7 @@ static void makeWritable(const Path& path) {
 
 struct MakeReadOnly {
   Path path;
-  MakeReadOnly(const Path& path) : path(path) {}
+  explicit MakeReadOnly(const Path& path) : path(path) {}
   ~MakeReadOnly() {
     try {
       /* This will make the path read-only. */
diff --git a/third_party/nix/src/libstore/remote-store.cc b/third_party/nix/src/libstore/remote-store.cc
index b0025df98f..e1fcb749a3 100644
--- a/third_party/nix/src/libstore/remote-store.cc
+++ b/third_party/nix/src/libstore/remote-store.cc
@@ -215,7 +215,7 @@ struct ConnectionHandle {
   Pool<RemoteStore::Connection>::Handle handle;
   bool daemonException = false;
 
-  ConnectionHandle(Pool<RemoteStore::Connection>::Handle&& handle)
+  explicit ConnectionHandle(Pool<RemoteStore::Connection>::Handle&& handle)
       : handle(std::move(handle)) {}
 
   ConnectionHandle(ConnectionHandle&& h) : handle(std::move(h.handle)) {}
diff --git a/third_party/nix/src/libutil/compression.cc b/third_party/nix/src/libutil/compression.cc
index e13ffcec74..93e2360bd5 100644
--- a/third_party/nix/src/libutil/compression.cc
+++ b/third_party/nix/src/libutil/compression.cc
@@ -34,7 +34,7 @@ struct ChunkedCompressionSink : CompressionSink {
 
 struct NoneSink : CompressionSink {
   Sink& nextSink;
-  NoneSink(Sink& nextSink) : nextSink(nextSink) {}
+  explicit NoneSink(Sink& nextSink) : nextSink(nextSink) {}
   void finish() override { flush(); }
   void write(const unsigned char* data, size_t len) override {
     nextSink(data, len);
@@ -47,7 +47,7 @@ struct XzDecompressionSink : CompressionSink {
   lzma_stream strm = LZMA_STREAM_INIT;
   bool finished = false;
 
-  XzDecompressionSink(Sink& nextSink) : nextSink(nextSink) {
+  explicit XzDecompressionSink(Sink& nextSink) : nextSink(nextSink) {
     lzma_ret ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
     if (ret != LZMA_OK) {
       throw CompressionError("unable to initialise lzma decoder");
@@ -92,7 +92,7 @@ struct BzipDecompressionSink : ChunkedCompressionSink {
   bz_stream strm;
   bool finished = false;
 
-  BzipDecompressionSink(Sink& nextSink) : nextSink(nextSink) {
+  explicit BzipDecompressionSink(Sink& nextSink) : nextSink(nextSink) {
     memset(&strm, 0, sizeof(strm));
     int ret = BZ2_bzDecompressInit(&strm, 0, 0);
     if (ret != BZ_OK) {
@@ -140,7 +140,7 @@ struct BrotliDecompressionSink : ChunkedCompressionSink {
   BrotliDecoderState* state;
   bool finished = false;
 
-  BrotliDecompressionSink(Sink& nextSink) : nextSink(nextSink) {
+  explicit BrotliDecompressionSink(Sink& nextSink) : nextSink(nextSink) {
     state = BrotliDecoderCreateInstance(nullptr, nullptr, nullptr);
     if (!state) {
       throw CompressionError("unable to initialize brotli decoder");
@@ -284,7 +284,7 @@ struct BzipCompressionSink : ChunkedCompressionSink {
   bz_stream strm;
   bool finished = false;
 
-  BzipCompressionSink(Sink& nextSink) : nextSink(nextSink) {
+  explicit BzipCompressionSink(Sink& nextSink) : nextSink(nextSink) {
     memset(&strm, 0, sizeof(strm));
     int ret = BZ2_bzCompressInit(&strm, 9, 0, 30);
     if (ret != BZ_OK) {
@@ -333,7 +333,7 @@ struct BrotliCompressionSink : ChunkedCompressionSink {
   BrotliEncoderState* state;
   bool finished = false;
 
-  BrotliCompressionSink(Sink& nextSink) : nextSink(nextSink) {
+  explicit BrotliCompressionSink(Sink& nextSink) : nextSink(nextSink) {
     state = BrotliEncoderCreateInstance(nullptr, nullptr, nullptr);
     if (!state) {
       throw CompressionError("unable to initialise brotli encoder");
diff --git a/third_party/nix/src/nix-daemon/nix-daemon.cc b/third_party/nix/src/nix-daemon/nix-daemon.cc
index 4f71a0c36f..0e5d7ac8ba 100644
--- a/third_party/nix/src/nix-daemon/nix-daemon.cc
+++ b/third_party/nix/src/nix-daemon/nix-daemon.cc
@@ -74,7 +74,7 @@ struct TunnelLogger {
 
   unsigned int clientVersion;
 
-  TunnelLogger(unsigned int clientVersion) : clientVersion(clientVersion) {}
+  explicit TunnelLogger(unsigned int clientVersion) : clientVersion(clientVersion) {}
 
   void enqueueMsg(const std::string& s) {
     auto state(state_.lock());
@@ -150,7 +150,7 @@ struct TunnelLogger {
 
 struct TunnelSink : Sink {
   Sink& to;
-  TunnelSink(Sink& to) : to(to) {}
+  explicit TunnelSink(Sink& to) : to(to) {}
   virtual void operator()(const unsigned char* data, size_t len) {
     to << STDERR_WRITE;
     writeString(data, len, to);
@@ -159,7 +159,7 @@ struct TunnelSink : Sink {
 
 struct TunnelSource : BufferedSource {
   Source& from;
-  TunnelSource(Source& from) : from(from) {}
+  explicit TunnelSource(Source& from) : from(from) {}
 
  protected:
   size_t readUnbuffered(unsigned char* data, size_t len) override {
diff --git a/third_party/nix/src/nix/hash.cc b/third_party/nix/src/nix/hash.cc
index 39780532f8..da4b64fe75 100644
--- a/third_party/nix/src/nix/hash.cc
+++ b/third_party/nix/src/nix/hash.cc
@@ -14,7 +14,7 @@ struct CmdHash : Command {
   HashType ht = htSHA256;
   std::vector<std::string> paths;
 
-  CmdHash(Mode mode) : mode(mode) {
+  explicit CmdHash(Mode mode) : mode(mode) {
     mkFlag(0, "sri", "print hash in SRI format", &base, SRI);
     mkFlag(0, "base64", "print hash in base-64", &base, Base64);
     mkFlag(0, "base32", "print hash in base-32 (Nix-specific)", &base, Base32);
@@ -52,7 +52,7 @@ struct CmdToBase : Command {
   HashType ht = htUnknown;
   std::vector<std::string> args;
 
-  CmdToBase(Base base) : base(base) {
+  explicit CmdToBase(Base base) : base(base) {
     mkFlag().longName("type").mkHashTypeFlag(&ht);
     expectArgs("strings", &args);
   }
diff --git a/third_party/nix/src/nix/installables.cc b/third_party/nix/src/nix/installables.cc
index 8a7de8655b..2d896e3bb9 100644
--- a/third_party/nix/src/nix/installables.cc
+++ b/third_party/nix/src/nix/installables.cc
@@ -100,7 +100,7 @@ Buildable Installable::toBuildable() {
 struct InstallableStorePath : Installable {
   Path storePath;
 
-  InstallableStorePath(const Path& storePath) : storePath(storePath) {}
+  explicit InstallableStorePath(const Path& storePath) : storePath(storePath) {}
 
   std::string what() override { return storePath; }
 
@@ -112,7 +112,7 @@ struct InstallableStorePath : Installable {
 struct InstallableValue : Installable {
   SourceExprCommand& cmd;
 
-  InstallableValue(SourceExprCommand& cmd) : cmd(cmd) {}
+  explicit InstallableValue(SourceExprCommand& cmd) : cmd(cmd) {}
 
   Buildables toBuildables() override {
     auto state = cmd.getEvalState();