1 files changed, 142 insertions, 0 deletions
diff --git a/third_party/nix/src/nix/doctor.cc b/third_party/nix/src/nix/doctor.cc
new file mode 100644
index 000000000000..d0b4c2b58873
--- /dev/null
+++ b/third_party/nix/src/nix/doctor.cc
@@ -0,0 +1,142 @@
+#include <absl/strings/match.h>
+#include <absl/strings/str_cat.h>
+#include <absl/strings/str_split.h>
+
+#include "libmain/shared.hh"
+#include "libstore/serve-protocol.hh"
+#include "libstore/store-api.hh"
+#include "libstore/worker-protocol.hh"
+#include "nix/command.hh"
+
+namespace nix {
+static std::string formatProtocol(unsigned int proto) {
+  if (proto != 0u) {
+    auto major = GET_PROTOCOL_MAJOR(proto) >> 8;
+    auto minor = GET_PROTOCOL_MINOR(proto);
+    return (format("%1%.%2%") % major % minor).str();
+  }
+  return "unknown";
+}
+
+struct CmdDoctor final : StoreCommand {
+  bool success = true;
+
+  std::string name() override { return "doctor"; }
+
+  std::string description() override {
+    return "check your system for potential problems";
+  }
+
+  void run(ref<Store> store) override {
+    std::cout << "Store uri: " << store->getUri() << std::endl;
+    std::cout << std::endl;
+
+    auto type = getStoreType();
+
+    if (type < tOther) {
+      success &= checkNixInPath();
+      success &= checkProfileRoots(store);
+    }
+    success &= checkStoreProtocol(store->getProtocol());
+
+    if (!success) {
+      throw Exit(2);
+    }
+  }
+
+  static bool checkNixInPath() {
+    PathSet dirs;
+
+    for (auto& dir : absl::StrSplit(getEnv("PATH").value_or(""),
+                                    absl::ByChar(':'), absl::SkipEmpty())) {
+      if (pathExists(absl::StrCat(dir, "/nix-env"))) {
+        dirs.insert(dirOf(canonPath(absl::StrCat(dir, "/nix-env"), true)));
+      }
+    }
+
+    if (dirs.size() != 1) {
+      std::cout << "Warning: multiple versions of nix found in PATH."
+                << std::endl;
+      std::cout << std::endl;
+      for (auto& dir : dirs) {
+        std::cout << "  " << dir << std::endl;
+      }
+      std::cout << std::endl;
+      return false;
+    }
+
+    return true;
+  }
+
+  static bool checkProfileRoots(const ref<Store>& store) {
+    PathSet dirs;
+
+    for (auto dir : absl::StrSplit(getEnv("PATH").value_or(""),
+                                   absl::ByChar(':'), absl::SkipEmpty())) {
+      Path profileDir = dirOf(dir);
+      try {
+        Path userEnv = canonPath(profileDir, true);
+
+        if (store->isStorePath(userEnv) &&
+            absl::EndsWith(userEnv, "user-environment")) {
+          while (profileDir.find("/profiles/") == std::string::npos &&
+                 isLink(profileDir)) {
+            profileDir = absPath(readLink(profileDir), dirOf(profileDir));
+          }
+
+          if (profileDir.find("/profiles/") == std::string::npos) {
+            dirs.insert(std::string(dir));
+          }
+        }
+      } catch (SysError&) {
+      }
+    }
+
+    if (!dirs.empty()) {
+      std::cout << "Warning: found profiles outside of " << settings.nixStateDir
+                << "/profiles." << std::endl;
+      std::cout << "The generation this profile points to might not have a "
+                   "gcroot and could be"
+                << std::endl;
+      std::cout << "garbage collected, resulting in broken symlinks."
+                << std::endl;
+      std::cout << std::endl;
+      for (auto& dir : dirs) {
+        std::cout << "  " << dir << std::endl;
+      }
+      std::cout << std::endl;
+      return false;
+    }
+
+    return true;
+  }
+
+  static bool checkStoreProtocol(unsigned int storeProto) {
+    unsigned int clientProto = GET_PROTOCOL_MAJOR(SERVE_PROTOCOL_VERSION) ==
+                                       GET_PROTOCOL_MAJOR(storeProto)
+                                   ? SERVE_PROTOCOL_VERSION
+                                   : PROTOCOL_VERSION;
+
+    if (clientProto != storeProto) {
+      std::cout << "Warning: protocol version of this client does not match "
+                   "the store."
+                << std::endl;
+      std::cout << "While this is not necessarily a problem it's recommended "
+                   "to keep the client in"
+                << std::endl;
+      std::cout << "sync with the daemon." << std::endl;
+      std::cout << std::endl;
+      std::cout << "Client protocol: " << formatProtocol(clientProto)
+                << std::endl;
+      std::cout << "Store protocol: " << formatProtocol(storeProto)
+                << std::endl;
+      std::cout << std::endl;
+      return false;
+    }
+
+    return true;
+  }
+};
+}  // namespace nix
+
+static nix::RegisterCommand r1(nix::make_ref<nix::CmdDoctor>());