6 files changed, 33 insertions, 29 deletions

diff --git a/third_party/nix/src/nix/edit.cc b/third_party/nix/src/nix/edit.cc
index 958e8aec49..94a42abb79 100644
--- a/third_party/nix/src/nix/edit.cc
+++ b/third_party/nix/src/nix/edit.cc
@@ -28,7 +28,7 @@ struct CmdEdit final : InstallableCommand {
 
     auto v = installable->toValue(*state);
 
-    Value* v2;
+    Value* v2 = nullptr;
     try {
       auto dummyArgs = Bindings::NewGC();
       v2 = findAlongAttrPath(*state, "meta.position", *dummyArgs, *v);
@@ -46,7 +46,7 @@ struct CmdEdit final : InstallableCommand {
     }
 
     std::string filename(pos, 0, colon);
-    int lineno;
+    int lineno = 0;
     try {
       lineno = std::stoi(std::string(pos, colon + 1));
     } catch (std::invalid_argument& e) {
diff --git a/third_party/nix/src/nix/main.cc b/third_party/nix/src/nix/main.cc
index 5536aac532..fa9ebe3743 100644
--- a/third_party/nix/src/nix/main.cc
+++ b/third_party/nix/src/nix/main.cc
@@ -25,7 +25,7 @@ namespace nix {
 
 /* Check if we have a non-loopback/link-local network interface. */
 static bool haveInternet() {
-  struct ifaddrs* addrs;
+  struct ifaddrs* addrs = nullptr;
 
   if (getifaddrs(&addrs) != 0) {
     return true;
@@ -38,7 +38,8 @@ static bool haveInternet() {
       continue;
     }
     if (i->ifa_addr->sa_family == AF_INET) {
-      if (ntohl(((sockaddr_in*)i->ifa_addr)->sin_addr.s_addr) !=
+      if (ntohl(
+              (reinterpret_cast<sockaddr_in*>(i->ifa_addr))->sin_addr.s_addr) !=
           INADDR_LOOPBACK) {
         return true;
       }
diff --git a/third_party/nix/src/nix/path-info.cc b/third_party/nix/src/nix/path-info.cc
index dca08b06ad..300a588a2e 100644
--- a/third_party/nix/src/nix/path-info.cc
+++ b/third_party/nix/src/nix/path-info.cc
@@ -96,7 +96,9 @@ struct CmdPathInfo final : StorePathsCommand, MixJSON {
 
         if (showSize || showClosureSize || showSigs) {
           std::cout << std::string(
-              std::max(0, (int)pathLen - (int)storePath.size()), ' ');
+              std::max(0, static_cast<int>(pathLen) -
+                              static_cast<int>(storePath.size())),
+              ' ');
         }
 
         if (showSize) {
diff --git a/third_party/nix/src/nix/repl.cc b/third_party/nix/src/nix/repl.cc
index 7644b7b8c2..91bf500893 100644
--- a/third_party/nix/src/nix/repl.cc
+++ b/third_party/nix/src/nix/repl.cc
@@ -38,14 +38,14 @@ namespace nix {
 struct NixRepl : gc {
   std::string curDir;
   EvalState state;
-  Bindings* autoArgs;
+  Bindings* autoArgs{};
 
   Strings loadedFiles;
 
   const static int envSize = 32768;
   StaticEnv staticEnv;
-  Env* env;
-  int displ;
+  Env* env{};
+  int displ{};
   StringSet varNames;
 
   const Path historyFile;
@@ -194,7 +194,7 @@ static int listPossibleCallback(char* s, char*** avp) {
     return p;
   };
 
-  vp = check((char**)malloc(possible.size() * sizeof(char*)));
+  vp = check(static_cast<char**>(malloc(possible.size() * sizeof(char*))));
 
   for (auto& p : possible) {
     vp[ac++] = check(strdup(p.c_str()));
@@ -272,8 +272,8 @@ void NixRepl::mainLoop(const std::vector<std::string>& files) {
 }
 
 bool NixRepl::getLine(std::string& input, const std::string& prompt) {
-  struct sigaction act;
-  struct sigaction old;
+  struct sigaction act {};
+  struct sigaction old {};
   sigset_t savedSignalMask;
   sigset_t set;
 
@@ -334,8 +334,8 @@ StringSet NixRepl::completePrefix(const std::string& prefix) {
     cur = std::string(prefix, start + 1);
   }
 
-  size_t slash;
-  size_t dot;
+  size_t slash = 0;
+  size_t dot = 0;
 
   if ((slash = cur.rfind('/')) != std::string::npos) {
     try {
@@ -367,7 +367,7 @@ StringSet NixRepl::completePrefix(const std::string& prefix) {
       std::string cur2 = std::string(cur, dot + 1);
 
       Expr* e = parseString(expr);
-      Value v;
+      Value v{};
       e->eval(state, *env, v);
       state.forceAttrs(v);
 
@@ -477,7 +477,7 @@ bool NixRepl::processLine(std::string line) {
   }
 
   else if (command == ":a" || command == ":add") {
-    Value v;
+    Value v{};
     evalString(arg, v);
     addAttrsToScope(v);
   }
@@ -493,14 +493,14 @@ bool NixRepl::processLine(std::string line) {
   }
 
   else if (command == ":t") {
-    Value v;
+    Value v{};
     evalString(arg, v);
     std::cout << showType(v) << std::endl;
 
   } else if (command == ":u") {
-    Value v;
-    Value f;
-    Value result;
+    Value v{};
+    Value f{};
+    Value result{};
     evalString(arg, v);
     evalString(
         "drv: (import <nixpkgs> {}).runCommand \"shell\" { buildInputs = [ drv "
@@ -513,7 +513,7 @@ bool NixRepl::processLine(std::string line) {
   }
 
   else if (command == ":b" || command == ":i" || command == ":s") {
-    Value v;
+    Value v{};
     evalString(arg, v);
     Path drvPath = getDerivationPath(v);
 
@@ -540,7 +540,7 @@ bool NixRepl::processLine(std::string line) {
   }
 
   else if (command == ":p" || command == ":print") {
-    Value v;
+    Value v{};
     evalString(arg, v);
     printValue(std::cout, v, 1000000000) << std::endl;
   }
@@ -563,7 +563,7 @@ bool NixRepl::processLine(std::string line) {
       v.thunk.expr = e;
       addVarToScope(state.symbols.Create(name), v);
     } else {
-      Value v;
+      Value v{};
       evalString(line, v);
       printValue(std::cout, v, 1) << std::endl;
     }
@@ -575,8 +575,8 @@ bool NixRepl::processLine(std::string line) {
 void NixRepl::loadFile(const Path& path) {
   loadedFiles.remove(path);
   loadedFiles.push_back(path);
-  Value v;
-  Value v2;
+  Value v{};
+  Value v2{};
   state.evalFile(lookupFileArg(state, path), v);
   state.autoCallFunction(*autoArgs, v, v2);
   addAttrsToScope(v2);
@@ -626,7 +626,7 @@ void NixRepl::addVarToScope(const Symbol& name, Value& v) {
   }
   staticEnv.vars[name] = displ;
   env->values[displ++] = &v;
-  varNames.insert((std::string)name);
+  varNames.insert(std::string(name));
 }
 
 Expr* NixRepl::parseString(const std::string& s) {
diff --git a/third_party/nix/src/nix/search.cc b/third_party/nix/src/nix/search.cc
index 2bfdeac6f7..b53f0b5088 100644
--- a/third_party/nix/src/nix/search.cc
+++ b/third_party/nix/src/nix/search.cc
@@ -196,8 +196,8 @@ struct CmdSearch final : SourceExprCommand, MixJSON {
                     : nullptr;
             doExpr(i.second.value,
                    attrPath.empty()
-                       ? (std::string)i.second.name
-                       : attrPath + "." + (std::string)i.second.name,
+                       ? std::string(i.second.name)
+                       : attrPath + "." + std::string(i.second.name),
                    toplevel2 || fromCache, cache2 ? cache2.get() : nullptr);
           }
         }
@@ -216,7 +216,7 @@ struct CmdSearch final : SourceExprCommand, MixJSON {
     if (useCache && pathExists(jsonCacheFileName)) {
       LOG(WARNING) << "using cached results; pass '-u' to update the cache";
 
-      Value vRoot;
+      Value vRoot{};
       parseJSON(*state, readFile(jsonCacheFileName), vRoot);
 
       fromCache = true;
diff --git a/third_party/nix/src/nix/verify.cc b/third_party/nix/src/nix/verify.cc
index a9959d50de..6552e3d1a7 100644
--- a/third_party/nix/src/nix/verify.cc
+++ b/third_party/nix/src/nix/verify.cc
@@ -99,7 +99,8 @@ struct CmdVerify final : StorePathsCommand {
 
           } else {
             StringSet sigsSeen;
-            size_t actualSigsNeeded = std::max(sigsNeeded, (size_t)1);
+            size_t actualSigsNeeded =
+                std::max(sigsNeeded, static_cast<size_t>(1));
             size_t validSigs = 0;
 
             auto doSigs = [&](const StringSet& sigs) {