Finish converting existing comments for internal API docs (#8146)

* Finish converting existing comments for internal API docs

99% of this was just reformatting existing comments. Only two exceptions:

- Expanded upon `BuildResult::status` compat note

- Split up file-level `symbol-table.hh` doc comments to get
  per-definition docs

Also fixed a few whitespace goofs, turning leading tabs to spaces and
removing trailing spaces.

Picking up from #8133

* Fix two things from comments

* Use triple-backtick not indent for `dumpPath`

* Convert GNU-style `\`..'` quotes to markdown style in API docs

This will render correctly.

27 files changed, 992 insertions, 478 deletions

diff --git a/src/libstore/binary-cache-store.hh b/src/libstore/binary-cache-store.hh
index 5e52d7844..49f271d24 100644
--- a/src/libstore/binary-cache-store.hh
+++ b/src/libstore/binary-cache-store.hh
@@ -46,6 +46,11 @@ struct BinaryCacheStoreConfig : virtual StoreConfig
         )"};
 };
 
+
+/**
+ * @note subclasses must implement at least one of the two
+ * virtual getFile() methods.
+ */
 class BinaryCacheStore : public virtual BinaryCacheStoreConfig,
     public virtual Store,
     public virtual LogStore
@@ -75,14 +80,15 @@ public:
         std::string && data,
         const std::string & mimeType);
 
-    /* Note: subclasses must implement at least one of the two
-       following getFile() methods. */
-
-    /* Dump the contents of the specified file to a sink. */
+    /**
+     * Dump the contents of the specified file to a sink.
+     */
     virtual void getFile(const std::string & path, Sink & sink);
 
-    /* Fetch the specified file and call the specified callback with
-       the result. A subclass may implement this asynchronously. */
+    /**
+     * Fetch the specified file and call the specified callback with
+     * the result. A subclass may implement this asynchronously.
+     */
     virtual void getFile(
         const std::string & path,
         Callback<std::optional<std::string>> callback) noexcept;
diff --git a/src/libstore/build-result.hh b/src/libstore/build-result.hh
index a12c599d9..27d1a1b6c 100644
--- a/src/libstore/build-result.hh
+++ b/src/libstore/build-result.hh
@@ -12,9 +12,12 @@ namespace nix {
 
 struct BuildResult
 {
-    /* Note: don't remove status codes, and only add new status codes
-       at the end of the list, to prevent client/server
-       incompatibilities in the nix-store --serve protocol. */
+    /**
+     * @note This is directly used in the nix-store --serve protocol.
+     * That means we need to worry about compatability across versions.
+     * Therefore, don't remove status codes, and only add new status
+     * codes at the end of the list.
+     */
     enum Status {
         Built = 0,
         Substituted,
@@ -22,8 +25,10 @@ struct BuildResult
         PermanentFailure,
         InputRejected,
         OutputRejected,
-        TransientFailure, // possibly transient
-        CachedFailure, // no longer used
+        /// possibly transient
+        TransientFailure,
+        /// no longer used
+        CachedFailure,
         TimedOut,
         MiscFailure,
         DependencyFailed,
@@ -33,7 +38,12 @@ struct BuildResult
         NoSubstituters,
     } status = MiscFailure;
 
-    // FIXME: include entire ErrorInfo object.
+    /**
+     * Information about the error if the build failed.
+     *
+     * @todo This should be an entire ErrorInfo object, not just a
+     * string, for richer information.
+     */
     std::string errorMsg;
 
     std::string toString() const {
@@ -60,27 +70,39 @@ struct BuildResult
         return strStatus + ((errorMsg == "") ? "" : " : " + errorMsg);
     }
 
-    /* How many times this build was performed. */
+    /**
+     * How many times this build was performed.
+     */
     unsigned int timesBuilt = 0;
 
-    /* If timesBuilt > 1, whether some builds did not produce the same
-       result. (Note that 'isNonDeterministic = false' does not mean
-       the build is deterministic, just that we don't have evidence of
-       non-determinism.) */
+    /**
+     * If timesBuilt > 1, whether some builds did not produce the same
+     * result. (Note that 'isNonDeterministic = false' does not mean
+     * the build is deterministic, just that we don't have evidence of
+     * non-determinism.)
+     */
     bool isNonDeterministic = false;
 
-    /* The derivation we built or the store path we substituted. */
+    /**
+     * The derivation we built or the store path we substituted.
+     */
     DerivedPath path;
 
-    /* For derivations, a mapping from the names of the wanted outputs
-       to actual paths. */
+    /**
+     * For derivations, a mapping from the names of the wanted outputs
+     * to actual paths.
+     */
     DrvOutputs builtOutputs;
 
-    /* The start/stop times of the build (or one of the rounds, if it
-       was repeated). */
+    /**
+     * The start/stop times of the build (or one of the rounds, if it
+     * was repeated).
+     */
     time_t startTime = 0, stopTime = 0;
 
-    /* User and system CPU time the build took. */
+    /**
+     * User and system CPU time the build took.
+     */
     std::optional<std::chrono::microseconds> cpuUser, cpuSystem;
 
     bool success()
diff --git a/src/libstore/build/derivation-goal.hh b/src/libstore/build/derivation-goal.hh
index f43ce22af..3a6f0c2d9 100644
--- a/src/libstore/build/derivation-goal.hh
+++ b/src/libstore/build/derivation-goal.hh
@@ -16,8 +16,10 @@ struct HookInstance;
 
 typedef enum {rpAccept, rpDecline, rpPostpone} HookReply;
 
-/* Unless we are repairing, we don't both to test validity and just assume it,
-   so the choices are `Absent` or `Valid`. */
+/**
+ * Unless we are repairing, we don't both to test validity and just assume it,
+ * so the choices are `Absent` or `Valid`.
+ */
 enum struct PathStatus {
     Corrupt,
     Absent,
@@ -27,11 +29,15 @@ enum struct PathStatus {
 struct InitialOutputStatus {
     StorePath path;
     PathStatus status;
-    /* Valid in the store, and additionally non-corrupt if we are repairing */
+    /**
+     * Valid in the store, and additionally non-corrupt if we are repairing
+     */
     bool isValid() const {
         return status == PathStatus::Valid;
     }
-    /* Merely present, allowed to be corrupt */
+    /**
+     * Merely present, allowed to be corrupt
+     */
     bool isPresent() const {
         return status == PathStatus::Corrupt
             || status == PathStatus::Valid;
@@ -46,59 +52,87 @@ struct InitialOutput {
 
 struct DerivationGoal : public Goal
 {
-    /* Whether to use an on-disk .drv file. */
+    /**
+     * Whether to use an on-disk .drv file.
+     */
     bool useDerivation;
 
-    /* The path of the derivation. */
+    /** The path of the derivation. */
     StorePath drvPath;
 
-    /* The goal for the corresponding resolved derivation */
+    /**
+     * The goal for the corresponding resolved derivation
+     */
     std::shared_ptr<DerivationGoal> resolvedDrvGoal;
 
-    /* The specific outputs that we need to build.  Empty means all of
-       them. */
+    /**
+     * The specific outputs that we need to build.  Empty means all of
+     * them.
+     */
     OutputsSpec wantedOutputs;
 
-    /* Mapping from input derivations + output names to actual store
-       paths. This is filled in by waiteeDone() as each dependency
-       finishes, before inputsRealised() is reached, */
+    /**
+     * Mapping from input derivations + output names to actual store
+     * paths. This is filled in by waiteeDone() as each dependency
+     * finishes, before inputsRealised() is reached.
+     */
     std::map<std::pair<StorePath, std::string>, StorePath> inputDrvOutputs;
 
-    /* Whether additional wanted outputs have been added. */
+    /**
+     * Whether additional wanted outputs have been added.
+     */
     bool needRestart = false;
 
-    /* Whether to retry substituting the outputs after building the
-       inputs. This is done in case of an incomplete closure. */
+    /**
+     * Whether to retry substituting the outputs after building the
+     * inputs. This is done in case of an incomplete closure.
+     */
     bool retrySubstitution = false;
 
-    /* Whether we've retried substitution, in which case we won't try
-       again. */
+    /**
+     * Whether we've retried substitution, in which case we won't try
+     * again.
+     */
     bool retriedSubstitution = false;
 
-    /* The derivation stored at drvPath. */
+    /**
+     * The derivation stored at drvPath.
+     */
     std::unique_ptr<Derivation> drv;
 
     std::unique_ptr<ParsedDerivation> parsedDrv;
 
-    /* The remainder is state held during the build. */
+    /**
+     * The remainder is state held during the build.
+     */
 
-    /* Locks on (fixed) output paths. */
+    /**
+     * Locks on (fixed) output paths.
+     */
     PathLocks outputLocks;
 
-    /* All input paths (that is, the union of FS closures of the
-       immediate input paths). */
+    /**
+     * All input paths (that is, the union of FS closures of the
+     * immediate input paths).
+     */
     StorePathSet inputPaths;
 
     std::map<std::string, InitialOutput> initialOutputs;
 
-    /* File descriptor for the log file. */
+    /**
+     * File descriptor for the log file.
+     */
     AutoCloseFD fdLogFile;
     std::shared_ptr<BufferedSink> logFileSink, logSink;
 
-    /* Number of bytes received from the builder's stdout/stderr. */
+    /**
+     * Number of bytes received from the builder's stdout/stderr.
+     */
     unsigned long logSize;
 
-    /* The most recent log lines. */
+    /**
+     * The most recent log lines.
+     */
     std::list<std::string> logTail;
 
     std::string currentLogLine;
@@ -106,10 +140,14 @@ struct DerivationGoal : public Goal
 
     std::string currentHookLine;
 
-    /* The build hook. */
+    /**
+     * The build hook.
+     */
     std::unique_ptr<HookInstance> hook;
 
-    /* The sort of derivation we are building. */
+    /**
+     * The sort of derivation we are building.
+     */
     DerivationType derivationType;
 
     typedef void (DerivationGoal::*GoalState)();
@@ -121,12 +159,16 @@ struct DerivationGoal : public Goal
 
     std::unique_ptr<Activity> act;
 
-    /* Activity that denotes waiting for a lock. */
+    /**
+     * Activity that denotes waiting for a lock.
+     */
     std::unique_ptr<Activity> actLock;
 
     std::map<ActivityId, Activity> builderActivities;
 
-    /* The remote machine on which we're building. */
+    /**
+     * The remote machine on which we're building.
+     */
     std::string machineName;
 
     DerivationGoal(const StorePath & drvPath,
@@ -143,10 +185,14 @@ struct DerivationGoal : public Goal
 
     void work() override;
 
-    /* Add wanted outputs to an already existing derivation goal. */
+    /**
+     * Add wanted outputs to an already existing derivation goal.
+     */
     void addWantedOutputs(const OutputsSpec & outputs);
 
-    /* The states. */
+    /**
+     * The states.
+     */
     void getDerivation();
     void loadDerivation();
     void haveDerivation();
@@ -160,28 +206,42 @@ struct DerivationGoal : public Goal
 
     void resolvedFinished();
 
-    /* Is the build hook willing to perform the build? */
+    /**
+     * Is the build hook willing to perform the build?
+     */
     HookReply tryBuildHook();
 
     virtual int getChildStatus();
 
-    /* Check that the derivation outputs all exist and register them
-       as valid. */
+    /**
+     * Check that the derivation outputs all exist and register them
+     * as valid.
+     */
     virtual DrvOutputs registerOutputs();
 
-    /* Open a log file and a pipe to it. */
+    /**
+     * Open a log file and a pipe to it.
+     */
     Path openLogFile();
 
-    /* Sign the newly built realisation if the store allows it */
+    /**
+     * Sign the newly built realisation if the store allows it
+     */
     virtual void signRealisation(Realisation&) {}
 
-    /* Close the log file. */
+    /**
+     * Close the log file.
+     */
     void closeLogFile();
 
-    /* Close the read side of the logger pipe. */
+    /**
+     * Close the read side of the logger pipe.
+     */
     virtual void closeReadPipes();
 
-    /* Cleanup hooks for buildDone() */
+    /**
+     * Cleanup hooks for buildDone()
+     */
     virtual void cleanupHookFinally();
     virtual void cleanupPreChildKill();
     virtual void cleanupPostChildKill();
@@ -191,30 +251,40 @@ struct DerivationGoal : public Goal
 
     virtual bool isReadDesc(int fd);
 
-    /* Callback used by the worker to write to the log. */
+    /**
+     * Callback used by the worker to write to the log.
+     */
     void handleChildOutput(int fd, std::string_view data) override;
     void handleEOF(int fd) override;
     void flushLine();
 
-    /* Wrappers around the corresponding Store methods that first consult the
-       derivation.  This is currently needed because when there is no drv file
-       there also is no DB entry. */
+    /**
+     * Wrappers around the corresponding Store methods that first consult the
+     * derivation.  This is currently needed because when there is no drv file
+     * there also is no DB entry.
+     */
     std::map<std::string, std::optional<StorePath>> queryPartialDerivationOutputMap();
     OutputPathMap queryDerivationOutputMap();
 
-    /* Update 'initialOutputs' to determine the current status of the
-       outputs of the derivation. Also returns a Boolean denoting
-       whether all outputs are valid and non-corrupt, and a
-       'DrvOutputs' structure containing the valid and wanted
-       outputs. */
+    /**
+     * Update 'initialOutputs' to determine the current status of the
+     * outputs of the derivation. Also returns a Boolean denoting
+     * whether all outputs are valid and non-corrupt, and a
+     * 'DrvOutputs' structure containing the valid and wanted
+     * outputs.
+     */
     std::pair<bool, DrvOutputs> checkPathValidity();
 
-    /* Aborts if any output is not valid or corrupt, and otherwise
-       returns a 'DrvOutputs' structure containing the wanted
-       outputs. */
+    /**
+     * Aborts if any output is not valid or corrupt, and otherwise
+     * returns a 'DrvOutputs' structure containing the wanted
+     * outputs.
+     */
     DrvOutputs assertPathValidity();
 
-    /* Forcibly kill the child process, if any. */
+    /**
+     * Forcibly kill the child process, if any.
+     */
     virtual void killChild();
 
     void repairClosure();
diff --git a/src/libstore/build/drv-output-substitution-goal.hh b/src/libstore/build/drv-output-substitution-goal.hh
index 3b6620b76..697ddb283 100644
--- a/src/libstore/build/drv-output-substitution-goal.hh
+++ b/src/libstore/build/drv-output-substitution-goal.hh
@@ -11,24 +11,34 @@ namespace nix {
 
 class Worker;
 
-// Substitution of a derivation output.
-// This is done in three steps:
-// 1. Fetch the output info from a substituter
-// 2. Substitute the corresponding output path
-// 3. Register the output info
+/**
+ * Substitution of a derivation output.
+ * This is done in three steps:
+ * 1. Fetch the output info from a substituter
+ * 2. Substitute the corresponding output path
+ * 3. Register the output info
+ */
 class DrvOutputSubstitutionGoal : public Goal {
 
-    // The drv output we're trying to substitue
+    /**
+     * The drv output we're trying to substitue
+     */
     DrvOutput id;
 
-    // The realisation corresponding to the given output id.
-    // Will be filled once we can get it.
+    /**
+     * The realisation corresponding to the given output id.
+     * Will be filled once we can get it.
+     */
     std::shared_ptr<const Realisation> outputInfo;
 
-    /* The remaining substituters. */
+    /**
+     * The remaining substituters.
+     */
     std::list<ref<Store>> subs;
 
-    /* The current substituter. */
+    /**
+     * The current substituter.
+     */
     std::shared_ptr<Store> sub;
 
     struct DownloadState
@@ -39,7 +49,9 @@ class DrvOutputSubstitutionGoal : public Goal {
 
     std::shared_ptr<DownloadState> downloadState;
 
-    /* Whether a substituter failed. */
+    /**
+     * Whether a substituter failed.
+     */
     bool substituterFailed = false;
 
 public:
diff --git a/src/libstore/build/goal.hh b/src/libstore/build/goal.hh
index 924a8bbd5..f4bf6f38b 100644
--- a/src/libstore/build/goal.hh
+++ b/src/libstore/build/goal.hh
@@ -7,11 +7,15 @@
 
 namespace nix {
 
-/* Forward definition. */
+/**
+ * Forward definition.
+ */
 struct Goal;
 class Worker;
 
-/* A pointer to a goal. */
+/**
+ * A pointer to a goal.
+ */
 typedef std::shared_ptr<Goal> GoalPtr;
 typedef std::weak_ptr<Goal> WeakGoalPtr;
 
@@ -19,48 +23,72 @@ struct CompareGoalPtrs {
     bool operator() (const GoalPtr & a, const GoalPtr & b) const;
 };
 
-/* Set of goals. */
+/**
+ * Set of goals.
+ */
 typedef std::set<GoalPtr, CompareGoalPtrs> Goals;
 typedef std::set<WeakGoalPtr, std::owner_less<WeakGoalPtr>> WeakGoals;
 
-/* A map of paths to goals (and the other way around). */
+/**
+ * A map of paths to goals (and the other way around).
+ */
 typedef std::map<StorePath, WeakGoalPtr> WeakGoalMap;
 
 struct Goal : public std::enable_shared_from_this<Goal>
 {
     typedef enum {ecBusy, ecSuccess, ecFailed, ecNoSubstituters, ecIncompleteClosure} ExitCode;
 
-    /* Backlink to the worker. */
+    /**
+     * Backlink to the worker.
+     */
     Worker & worker;
 
-    /* Goals that this goal is waiting for. */
+    /**
+     * Goals that this goal is waiting for.
+     */
     Goals waitees;
 
-    /* Goals waiting for this one to finish.  Must use weak pointers
-       here to prevent cycles. */
+    /**
+     * Goals waiting for this one to finish.  Must use weak pointers
+     * here to prevent cycles.
+     */
     WeakGoals waiters;
 
-    /* Number of goals we are/were waiting for that have failed. */
+    /**
+     * Number of goals we are/were waiting for that have failed.
+     */
     size_t nrFailed = 0;
 
-    /* Number of substitution goals we are/were waiting for that
-       failed because there are no substituters. */
+    /**
+     * Number of substitution goals we are/were waiting for that
+     * failed because there are no substituters.
+     */
     size_t nrNoSubstituters = 0;
 
-    /* Number of substitution goals we are/were waiting for that
-       failed because they had unsubstitutable references. */
+    /**
+     * Number of substitution goals we are/were waiting for that
+     * failed because they had unsubstitutable references.
+     */
     size_t nrIncompleteClosure = 0;
 
-    /* Name of this goal for debugging purposes. */
+    /**
+     * Name of this goal for debugging purposes.
+     */
     std::string name;
 
-    /* Whether the goal is finished. */
+    /**
+     * Whether the goal is finished.
+     */
     ExitCode exitCode = ecBusy;
 
-    /* Build result. */
+    /**
+     * Build result.
+     */
     BuildResult buildResult;
 
-    /* Exception containing an error message, if any. */
+    /**
+     * Exception containing an error message, if any.
+     */
     std::optional<Error> ex;
 
     Goal(Worker & worker, DerivedPath path)
@@ -96,9 +124,11 @@ struct Goal : public std::enable_shared_from_this<Goal>
         return name;
     }
 
-    /* Callback in case of a timeout.  It should wake up its waiters,
-       get rid of any running child processes that are being monitored
-       by the worker (important!), etc. */
+    /**
+     * Callback in case of a timeout.  It should wake up its waiters,
+     * get rid of any running child processes that are being monitored
+     * by the worker (important!), etc.
+     */
     virtual void timedOut(Error && ex) = 0;
 
     virtual std::string key() = 0;
diff --git a/src/libstore/build/hook-instance.hh b/src/libstore/build/hook-instance.hh
index 6bf60b297..d84f62877 100644
--- a/src/libstore/build/hook-instance.hh
+++ b/src/libstore/build/hook-instance.hh
@@ -8,16 +8,24 @@ namespace nix {
 
 struct HookInstance
 {
-    /* Pipes for talking to the build hook. */
+    /**
+     * Pipes for talking to the build hook.
+     */
     Pipe toHook;
 
-    /* Pipe for the hook's standard output/error. */
+    /**
+     * Pipe for the hook's standard output/error.
+     */
     Pipe fromHook;
 
-    /* Pipe for the builder's standard output/error. */
+    /**
+     * Pipe for the builder's standard output/error.
+     */
     Pipe builderOut;
 
-    /* The process ID of the hook. */
+    /**
+     * The process ID of the hook.
+     */
     Pid pid;
 
     FdSink sink;
diff --git a/src/libstore/build/local-derivation-goal.hh b/src/libstore/build/local-derivation-goal.hh
index 1c4b4e3fe..42d32a31a 100644
--- a/src/libstore/build/local-derivation-goal.hh
+++ b/src/libstore/build/local-derivation-goal.hh
@@ -10,49 +10,75 @@ struct LocalDerivationGoal : public DerivationGoal
 {
     LocalStore & getLocalStore();
 
-    /* User selected for running the builder. */
+    /**
+     * User selected for running the builder.
+     */
     std::unique_ptr<UserLock> buildUser;
 
-    /* The process ID of the builder. */
+    /**
+     * The process ID of the builder.
+     */
     Pid pid;
 
-    /* The cgroup of the builder, if any. */
+    /**
+     * The cgroup of the builder, if any.
+     */
     std::optional<Path> cgroup;
 
-    /* The temporary directory. */
+    /**
+     * The temporary directory.
+     */
     Path tmpDir;
 
-    /* The path of the temporary directory in the sandbox. */
+    /**
+     * The path of the temporary directory in the sandbox.
+     */
     Path tmpDirInSandbox;
 
-    /* Master side of the pseudoterminal used for the builder's
-       standard output/error. */
+    /**
+     * Master side of the pseudoterminal used for the builder's
+     * standard output/error.
+     */
     AutoCloseFD builderOut;
 
-    /* Pipe for synchronising updates to the builder namespaces. */
+    /**
+     * Pipe for synchronising updates to the builder namespaces.
+     */
     Pipe userNamespaceSync;
 
-    /* The mount namespace and user namespace of the builder, used to add additional
-       paths to the sandbox as a result of recursive Nix calls. */
+    /**
+     * The mount namespace and user namespace of the builder, used to add additional
+     * paths to the sandbox as a result of recursive Nix calls.
+     */
     AutoCloseFD sandboxMountNamespace;
     AutoCloseFD sandboxUserNamespace;
 
-    /* On Linux, whether we're doing the build in its own user
-       namespace. */
+    /**
+     * On Linux, whether we're doing the build in its own user
+     * namespace.
+     */
     bool usingUserNamespace = true;
 
-    /* Whether we're currently doing a chroot build. */
+    /**
+     * Whether we're currently doing a chroot build.
+     */
     bool useChroot = false;
 
     Path chrootRootDir;
 
-    /* RAII object to delete the chroot directory. */
+    /**
+     * RAII object to delete the chroot directory.
+     */
     std::shared_ptr<AutoDelete> autoDelChroot;
 
-    /* Whether to run the build in a private network namespace. */
+    /**
+     * Whether to run the build in a private network namespace.
+     */
     bool privateNetwork = false;
 
-    /* Stuff we need to pass to initChild(). */
+    /**
+     * Stuff we need to pass to initChild().
+     */
     struct ChrootPath {
         Path source;
         bool optional;
@@ -71,30 +97,35 @@ struct LocalDerivationGoal : public DerivationGoal
     SandboxProfile additionalSandboxProfile;
 #endif
 
-    /* Hash rewriting. */
+    /**
+     * Hash rewriting.
+     */
     StringMap inputRewrites, outputRewrites;
     typedef map<StorePath, StorePath> RedirectedOutputs;
     RedirectedOutputs redirectedOutputs;
 
-    /* The outputs paths used during the build.
-
-       - Input-addressed derivations or fixed content-addressed outputs are
-         sometimes built when some of their outputs already exist, and can not
-         be hidden via sandboxing. We use temporary locations instead and
-         rewrite after the build. Otherwise the regular predetermined paths are
-         put here.
-
-       - Floating content-addressed derivations do not know their final build
-         output paths until the outputs are hashed, so random locations are
-         used, and then renamed. The randomness helps guard against hidden
-         self-references.
+    /**
+     * The outputs paths used during the build.
+     *
+     * - Input-addressed derivations or fixed content-addressed outputs are
+     *   sometimes built when some of their outputs already exist, and can not
+     *   be hidden via sandboxing. We use temporary locations instead and
+     *   rewrite after the build. Otherwise the regular predetermined paths are
+     *   put here.
+     *
+     * - Floating content-addressed derivations do not know their final build
+     *   output paths until the outputs are hashed, so random locations are
+     *   used, and then renamed. The randomness helps guard against hidden
+     *   self-references.
      */
     OutputPathMap scratchOutputs;
 
-    /* Path registration info from the previous round, if we're
-       building multiple times. Since this contains the hash, it
-       allows us to compare whether two rounds produced the same
-       result. */
+    /**
+     * Path registration info from the previous round, if we're
+     * building multiple times. Since this contains the hash, it
+     * allows us to compare whether two rounds produced the same
+     * result.
+     */
     std::map<Path, ValidPathInfo> prevInfos;
 
     uid_t sandboxUid() { return usingUserNamespace ? (!buildUser || buildUser->getUIDCount() == 1 ? 1000 : 0) : buildUser->getUID(); }
@@ -102,25 +133,37 @@ struct LocalDerivationGoal : public DerivationGoal
 
     const static Path homeDir;
 
-    /* The recursive Nix daemon socket. */
+    /**
+     * The recursive Nix daemon socket.
+     */
     AutoCloseFD daemonSocket;
 
-    /* The daemon main thread. */
+    /**
+     * The daemon main thread.
+     */
     std::thread daemonThread;
 
-    /* The daemon worker threads. */
+    /**
+     * The daemon worker threads.
+     */
     std::vector<std::thread> daemonWorkerThreads;
 
-    /* Paths that were added via recursive Nix calls. */
+    /**
+     * Paths that were added via recursive Nix calls.
+     */
     StorePathSet addedPaths;
 
-    /* Realisations that were added via recursive Nix calls. */
+    /**
+     * Realisations that were added via recursive Nix calls.
+     */
     std::set<DrvOutput> addedDrvOutputs;
 
-    /* Recursive Nix calls are only allowed to build or realize paths
-       in the original input closure or added via a recursive Nix call
-       (so e.g. you can't do 'nix-store -r /nix/store/<bla>' where
-       /nix/store/<bla> is some arbitrary path in a binary cache). */
+    /**
+     * Recursive Nix calls are only allowed to build or realize paths
+     * in the original input closure or added via a recursive Nix call
+     * (so e.g. you can't do 'nix-store -r /nix/store/<bla>' where
+     * /nix/store/<bla> is some arbitrary path in a binary cache).
+     */
     bool isAllowed(const StorePath & path)
     {
         return inputPaths.count(path) || addedPaths.count(path);
@@ -138,55 +181,81 @@ struct LocalDerivationGoal : public DerivationGoal
 
     virtual ~LocalDerivationGoal() override;
 
-    /* Whether we need to perform hash rewriting if there are valid output paths. */
+    /**
+     * Whether we need to perform hash rewriting if there are valid output paths.
+     */
     bool needsHashRewrite();
 
-    /* The additional states. */
+    /**
+     * The additional states.
+     */
     void tryLocalBuild() override;
 
-    /* Start building a derivation. */
+    /**
+     * Start building a derivation.
+     */
     void startBuilder();
 
-    /* Fill in the environment for the builder. */
+    /**
+     * Fill in the environment for the builder.
+     */
     void initEnv();
 
-    /* Setup tmp dir location. */
+    /**
+     * Setup tmp dir location.
+     */
     void initTmpDir();
 
-    /* Write a JSON file containing the derivation attributes. */
+    /**
+     * Write a JSON file containing the derivation attributes.
+     */
     void writeStructuredAttrs();
 
     void startDaemon();
 
     void stopDaemon();
 
-    /* Add 'path' to the set of paths that may be referenced by the
-       outputs, and make it appear in the sandbox. */
+    /**
+     * Add 'path' to the set of paths that may be referenced by the
+     * outputs, and make it appear in the sandbox.
+     */
     void addDependency(const StorePath & path);
 
-    /* Make a file owned by the builder. */
+    /**
+     * Make a file owned by the builder.
+     */
     void chownToBuilder(const Path & path);
 
     int getChildStatus() override;
 
-    /* Run the builder's process. */
+    /**
+     * Run the builder's process.
+     */
     void runChild();
 
-    /* Check that the derivation outputs all exist and register them
-       as valid. */
+    /**
+     * Check that the derivation outputs all exist and register them
+     * as valid.
+     */
     DrvOutputs registerOutputs() override;
 
     void signRealisation(Realisation &) override;
 
-    /* Check that an output meets the requirements specified by the
-       'outputChecks' attribute (or the legacy
-       '{allowed,disallowed}{References,Requisites}' attributes). */
+    /**
+     * Check that an output meets the requirements specified by the
+     * 'outputChecks' attribute (or the legacy
+     * '{allowed,disallowed}{References,Requisites}' attributes).
+     */
     void checkOutputs(const std::map<std::string, ValidPathInfo> & outputs);
 
-    /* Close the read side of the logger pipe. */
+    /**
+     * Close the read side of the logger pipe.
+     */
     void closeReadPipes() override;
 
-    /* Cleanup hooks for buildDone() */
+    /**
+     * Cleanup hooks for buildDone()
+     */
     void cleanupHookFinally() override;
     void cleanupPreChildKill() override;
     void cleanupPostChildKill() override;
@@ -196,24 +265,36 @@ struct LocalDerivationGoal : public DerivationGoal
 
     bool isReadDesc(int fd) override;
 
-    /* Delete the temporary directory, if we have one. */
+    /**
+     * Delete the temporary directory, if we have one.
+     */
     void deleteTmpDir(bool force);
 
-    /* Forcibly kill the child process, if any. */
+    /**
+     * Forcibly kill the child process, if any.
+     */
     void killChild() override;
 
-    /* Kill any processes running under the build user UID or in the
-       cgroup of the build. */
+    /**
+     * Kill any processes running under the build user UID or in the
+     * cgroup of the build.
+     */
     void killSandbox(bool getStats);
 
-    /* Create alternative path calculated from but distinct from the
-       input, so we can avoid overwriting outputs (or other store paths)
-       that already exist. */
+    /**
+     * Create alternative path calculated from but distinct from the
+     * input, so we can avoid overwriting outputs (or other store paths)
+     * that already exist.
+     */
     StorePath makeFallbackPath(const StorePath & path);
-    /* Make a path to another based on the output name along with the
-       derivation hash. */
-    /* FIXME add option to randomize, so we can audit whether our
-       rewrites caught everything */
+
+    /**
+     * Make a path to another based on the output name along with the
+     * derivation hash.
+     *
+     * @todo Add option to randomize, so we can audit whether our
+     * rewrites caught everything
+     */
     StorePath makeFallbackPath(std::string_view outputName);
 };
 
diff --git a/src/libstore/build/substitution-goal.hh b/src/libstore/build/substitution-goal.hh
index 1add9eb14..c2b7fc95a 100644
--- a/src/libstore/build/substitution-goal.hh
+++ b/src/libstore/build/substitution-goal.hh
@@ -11,38 +11,58 @@ class Worker;
 
 struct PathSubstitutionGoal : public Goal
 {
-    /* The store path that should be realised through a substitute. */
+    /**
+     * The store path that should be realised through a substitute.
+     */
     StorePath storePath;
 
-    /* The path the substituter refers to the path as. This will be
-       different when the stores have different names. */
+    /**
+     * The path the substituter refers to the path as. This will be
+     * different when the stores have different names.
+     */
     std::optional<StorePath> subPath;
 
-    /* The remaining substituters. */
+    /**
+     * The remaining substituters.
+     */
     std::list<ref<Store>> subs;
 
-    /* The current substituter. */
+    /**
+     * The current substituter.
+     */
     std::shared_ptr<Store> sub;
 
-    /* Whether a substituter failed. */
+    /**
+     * Whether a substituter failed.
+     */
     bool substituterFailed = false;
 
-    /* Path info returned by the substituter's query info operation. */
+    /**
+     * Path info returned by the substituter's query info operation.
+     */
     std::shared_ptr<const ValidPathInfo> info;
 
-    /* Pipe for the substituter's standard output. */
+    /**
+     * Pipe for the substituter's standard output.
+     */
     Pipe outPipe;
 
-    /* The substituter thread. */
+    /**
+     * The substituter thread.
+     */
     std::thread thr;
 
     std::promise<void> promise;
 
-    /* Whether to try to repair a valid path. */
+    /**
+     * Whether to try to repair a valid path.
+     */
     RepairFlag repair;
 
-    /* Location where we're downloading the substitute.  Differs from
-       storePath when doing a repair. */
+    /**
+     * Location where we're downloading the substitute.  Differs from
+     * storePath when doing a repair.
+     */
     Path destPath;
 
     std::unique_ptr<MaintainCount<uint64_t>> maintainExpectedSubstitutions,
@@ -51,7 +71,9 @@ struct PathSubstitutionGoal : public Goal
     typedef void (PathSubstitutionGoal::*GoalState)();
     GoalState state;
 
-    /* Content address for recomputing store path */
+    /**
+     * Content address for recomputing store path
+     */
     std::optional<ContentAddress> ca;
 
     void done(
@@ -65,16 +87,20 @@ public:
 
     void timedOut(Error && ex) override { abort(); };
 
+    /**
+     * We prepend "a$" to the key name to ensure substitution goals
+     * happen before derivation goals.
+     */
     std::string key() override
     {
-        /* "a$" ensures substitution goals happen before derivation
-           goals. */
         return "a$" + std::string(storePath.name()) + "$" + worker.store.printStorePath(storePath);
     }
 
     void work() override;
 
-    /* The states. */
+    /**
+     * The states.
+     */
     void init();
     void tryNext();
     void gotInfo();
@@ -82,7 +108,9 @@ public:
     void tryToRun();
     void finished();
 
-    /* Callback used by the worker to write to the log. */
+    /**
+     * Callback used by the worker to write to the log.
+     */
     void handleChildOutput(int fd, std::string_view data) override;
     void handleEOF(int fd) override;
 
diff --git a/src/libstore/build/worker.hh b/src/libstore/build/worker.hh
index d840b3b3f..48a1a27fa 100644
--- a/src/libstore/build/worker.hh
+++ b/src/libstore/build/worker.hh
@@ -17,24 +17,29 @@ struct DerivationGoal;
 struct PathSubstitutionGoal;
 class DrvOutputSubstitutionGoal;
 
-/* Workaround for not being able to declare a something like
-
-     class PathSubstitutionGoal : public Goal;
-
-   even when Goal is a complete type.
-
-   This is still a static cast. The purpose of exporting it is to define it in
-   a place where `PathSubstitutionGoal` is concrete, and use it in a place where it
-   is opaque. */
+/**
+ * Workaround for not being able to declare a something like
+ *
+ * ```c++
+ * class PathSubstitutionGoal : public Goal;
+ * ```
+ * even when Goal is a complete type.
+ *
+ * This is still a static cast. The purpose of exporting it is to define it in
+ * a place where `PathSubstitutionGoal` is concrete, and use it in a place where it
+ * is opaque.
+ */
 GoalPtr upcast_goal(std::shared_ptr<PathSubstitutionGoal> subGoal);
 GoalPtr upcast_goal(std::shared_ptr<DrvOutputSubstitutionGoal> subGoal);
 
 typedef std::chrono::time_point<std::chrono::steady_clock> steady_time_point;
 
 
-/* A mapping used to remember for each child process to what goal it
-   belongs, and file descriptors for receiving log data and output
-   path creation commands. */
+/**
+ * A mapping used to remember for each child process to what goal it
+ * belongs, and file descriptors for receiving log data and output
+ * path creation commands.
+ */
 struct Child
 {
     WeakGoalPtr goal;
@@ -42,14 +47,19 @@ struct Child
     std::set<int> fds;
     bool respectTimeouts;
     bool inBuildSlot;
-    steady_time_point lastOutput; /* time we last got output on stdout/stderr */
+    /**
+     * Time we last got output on stdout/stderr
+     */
+    steady_time_point lastOutput;
     steady_time_point timeStarted;
 };
 
 /* Forward definition. */
 struct HookInstance;
 
-/* The worker class. */
+/**
+ * The worker class.
+ */
 class Worker
 {
 private:
@@ -57,38 +67,58 @@ private:
     /* Note: the worker should only have strong pointers to the
        top-level goals. */
 
-    /* The top-level goals of the worker. */
+    /**
+     * The top-level goals of the worker.
+     */
     Goals topGoals;
 
-    /* Goals that are ready to do some work. */
+    /**
+     * Goals that are ready to do some work.
+     */
     WeakGoals awake;
 
-    /* Goals waiting for a build slot. */
+    /**
+     * Goals waiting for a build slot.
+     */
     WeakGoals wantingToBuild;
 
-    /* Child processes currently running. */
+    /**
+     * Child processes currently running.
+     */
     std::list<Child> children;
 
-    /* Number of build slots occupied.  This includes local builds and
-       substitutions but not remote builds via the build hook. */
+    /**
+     * Number of build slots occupied.  This includes local builds and
+     * substitutions but not remote builds via the build hook.
+     */
     unsigned int nrLocalBuilds;
 
-    /* Maps used to prevent multiple instantiations of a goal for the
-       same derivation / path. */
+    /**
+     * Maps used to prevent multiple instantiations of a goal for the
+     * same derivation / path.
+     */
     std::map<StorePath, std::weak_ptr<DerivationGoal>> derivationGoals;
     std::map<StorePath, std::weak_ptr<PathSubstitutionGoal>> substitutionGoals;
     std::map<DrvOutput, std::weak_ptr<DrvOutputSubstitutionGoal>> drvOutputSubstitutionGoals;
 
-    /* Goals waiting for busy paths to be unlocked. */
+    /**
+     * Goals waiting for busy paths to be unlocked.
+     */
     WeakGoals waitingForAnyGoal;
 
-    /* Goals sleeping for a few seconds (polling a lock). */
+    /**
+     * Goals sleeping for a few seconds (polling a lock).
+     */
     WeakGoals waitingForAWhile;
 
-    /* Last time the goals in `waitingForAWhile' where woken up. */
+    /**
+     * Last time the goals in `waitingForAWhile` where woken up.
+     */
     steady_time_point lastWokenUp;
 
-    /* Cache for pathContentsGood(). */
+    /**
+     * Cache for pathContentsGood().
+     */
     std::map<StorePath, bool> pathContentsGoodCache;
 
 public:
@@ -97,17 +127,25 @@ public:
     const Activity actDerivations;
     const Activity actSubstitutions;
 
-    /* Set if at least one derivation had a BuildError (i.e. permanent
-       failure). */
+    /**
+     * Set if at least one derivation had a BuildError (i.e. permanent
+     * failure).
+     */
     bool permanentFailure;
 
-    /* Set if at least one derivation had a timeout. */
+    /**
+     * Set if at least one derivation had a timeout.
+     */
     bool timedOut;
 
-    /* Set if at least one derivation fails with a hash mismatch. */
+    /**
+     * Set if at least one derivation fails with a hash mismatch.
+     */
     bool hashMismatch;
 
-    /* Set if at least one derivation is not deterministic in check mode. */
+    /**
+     * Set if at least one derivation is not deterministic in check mode.
+     */
     bool checkMismatch;
 
     Store & store;
@@ -129,16 +167,22 @@ public:
     uint64_t expectedNarSize = 0;
     uint64_t doneNarSize = 0;
 
-    /* Whether to ask the build hook if it can build a derivation. If
-       it answers with "decline-permanently", we don't try again. */
+    /**
+     * Whether to ask the build hook if it can build a derivation. If
+     * it answers with "decline-permanently", we don't try again.
+     */
     bool tryBuildHook = true;
 
     Worker(Store & store, Store & evalStore);
     ~Worker();
 
-    /* Make a goal (with caching). */
+    /**
+     * Make a goal (with caching).
+     */
 
-    /* derivation goal */
+    /**
+     * derivation goal
+     */
 private:
     std::shared_ptr<DerivationGoal> makeDerivationGoalCommon(
         const StorePath & drvPath, const OutputsSpec & wantedOutputs,
@@ -151,56 +195,80 @@ public:
         const StorePath & drvPath, const BasicDerivation & drv,
         const OutputsSpec & wantedOutputs, BuildMode buildMode = bmNormal);
 
-    /* substitution goal */
+    /**
+     * substitution goal
+     */
     std::shared_ptr<PathSubstitutionGoal> makePathSubstitutionGoal(const StorePath & storePath, RepairFlag repair = NoRepair, std::optional<ContentAddress> ca = std::nullopt);
     std::shared_ptr<DrvOutputSubstitutionGoal> makeDrvOutputSubstitutionGoal(const DrvOutput & id, RepairFlag repair = NoRepair, std::optional<ContentAddress> ca = std::nullopt);
 
-    /* Remove a dead goal. */
+    /**
+     * Remove a dead goal.
+     */
     void removeGoal(GoalPtr goal);
 
-    /* Wake up a goal (i.e., there is something for it to do). */
+    /**
+     * Wake up a goal (i.e., there is something for it to do).
+     */
     void wakeUp(GoalPtr goal);
 
-    /* Return the number of local build and substitution processes
-       currently running (but not remote builds via the build
-       hook). */
+    /**
+     * Return the number of local build and substitution processes
+     * currently running (but not remote builds via the build
+     * hook).
+     */
     unsigned int getNrLocalBuilds();
 
-    /* Registers a running child process.  `inBuildSlot' means that
-       the process counts towards the jobs limit. */
+    /**
+     * Registers a running child process.  `inBuildSlot` means that
+     * the process counts towards the jobs limit.
+     */
     void childStarted(GoalPtr goal, const std::set<int> & fds,
         bool inBuildSlot, bool respectTimeouts);
 
-    /* Unregisters a running child process.  `wakeSleepers' should be
-       false if there is no sense in waking up goals that are sleeping
-       because they can't run yet (e.g., there is no free build slot,
-       or the hook would still say `postpone'). */
+    /**
+     * Unregisters a running child process.  `wakeSleepers` should be
+     * false if there is no sense in waking up goals that are sleeping
+     * because they can't run yet (e.g., there is no free build slot,
+     * or the hook would still say `postpone`).
+     */
     void childTerminated(Goal * goal, bool wakeSleepers = true);
 
-    /* Put `goal' to sleep until a build slot becomes available (which
-       might be right away). */
+    /**
+     * Put `goal` to sleep until a build slot becomes available (which
+     * might be right away).
+     */
     void waitForBuildSlot(GoalPtr goal);
 
-    /* Wait for any goal to finish.  Pretty indiscriminate way to
-       wait for some resource that some other goal is holding. */
+    /**
+     * Wait for any goal to finish.  Pretty indiscriminate way to
+     * wait for some resource that some other goal is holding.
+     */
     void waitForAnyGoal(GoalPtr goal);
 
-    /* Wait for a few seconds and then retry this goal.  Used when
-       waiting for a lock held by another process.  This kind of
-       polling is inefficient, but POSIX doesn't really provide a way
-       to wait for multiple locks in the main select() loop. */
+    /**
+     * Wait for a few seconds and then retry this goal.  Used when
+     * waiting for a lock held by another process.  This kind of
+     * polling is inefficient, but POSIX doesn't really provide a way
+     * to wait for multiple locks in the main select() loop.
+     */
     void waitForAWhile(GoalPtr goal);
 
-    /* Loop until the specified top-level goals have finished. */
+    /**
+     * Loop until the specified top-level goals have finished.
+     */
     void run(const Goals & topGoals);
 
-    /* Wait for input to become available. */
+    /**
+     * Wait for input to become available.
+     */
     void waitForInput();
 
     unsigned int exitStatus();
 
-    /* Check whether the given valid path exists and has the right
-       contents. */
+    /**
+     * Check whether the given valid path exists and has the right
+     * contents.
+     */
     bool pathContentsGood(const StorePath & path);
 
     void markContentsGood(const StorePath & path);
diff --git a/src/libstore/crypto.hh b/src/libstore/crypto.hh
index a98f2a3b8..35216d470 100644
--- a/src/libstore/crypto.hh
+++ b/src/libstore/crypto.hh
@@ -12,8 +12,10 @@ struct Key
     std::string name;
     std::string key;
 
-    /* Construct Key from a string in the format
-       ‘<name>:<key-in-base64>’. */
+    /**
+     * Construct Key from a string in the format
+     * ‘<name>:<key-in-base64>’.
+     */
     Key(std::string_view s);
 
     std::string to_string() const;
@@ -29,7 +31,9 @@ struct SecretKey : Key
 {
     SecretKey(std::string_view s);
 
-    /* Return a detached signature of the given string. */
+    /**
+     * Return a detached signature of the given string.
+     */
     std::string signDetached(std::string_view s) const;
 
     PublicKey toPublicKey() const;
@@ -53,8 +57,10 @@ private:
 
 typedef std::map<std::string, PublicKey> PublicKeys;
 
-/* Return true iff ‘sig’ is a correct signature over ‘data’ using one
-   of the given public keys. */
+/**
+ * @return true iff ‘sig’ is a correct signature over ‘data’ using one
+ * of the given public keys.
+ */
 bool verifyDetached(const std::string & data, const std::string & sig,
     const PublicKeys & publicKeys);
 
diff --git a/src/libstore/derivations.hh b/src/libstore/derivations.hh
index 9e7ceeb5d..ccdde36ca 100644
--- a/src/libstore/derivations.hh
+++ b/src/libstore/derivations.hh
@@ -258,8 +258,14 @@ struct DerivationType : _DerivationTypeRaw {
 
 struct BasicDerivation
 {
-    DerivationOutputs outputs; /* keyed on symbolic IDs */
-    StorePathSet inputSrcs; /* inputs that are sources */
+    /**
+     * keyed on symbolic IDs
+     */
+    DerivationOutputs outputs;
+    /**
+     * inputs that are sources
+     */
+    StorePathSet inputSrcs;
     std::string platform;
     Path builder;
     Strings args;
@@ -429,12 +435,12 @@ void operator |= (DrvHash::Kind & self, const DrvHash::Kind & other) noexcept;
  *
  * A fixed-output derivation is a derivation whose outputs have a
  * specified content hash and hash algorithm. (Currently they must have
- * exactly one output (`out'), which is specified using the `outputHash'
- * and `outputHashAlgo' attributes, but the algorithm doesn't assume
+ * exactly one output (`out`), which is specified using the `outputHash`
+ * and `outputHashAlgo` attributes, but the algorithm doesn't assume
  * this.) We don't want changes to such derivations to propagate upwards
  * through the dependency graph, changing output paths everywhere.
  *
- * For instance, if we change the url in a call to the `fetchurl'
+ * For instance, if we change the url in a call to the `fetchurl`
  * function, we do not want to rebuild everything depending on it---after
  * all, (the hash of) the file being downloaded is unchanged.  So the
  * *output paths* should not change. On the other hand, the *derivation
diff --git a/src/libstore/fs-accessor.hh b/src/libstore/fs-accessor.hh
index 1c98a42d7..1df19e647 100644
--- a/src/libstore/fs-accessor.hh
+++ b/src/libstore/fs-accessor.hh
@@ -5,8 +5,10 @@
 
 namespace nix {
 
-/* An abstract class for accessing a filesystem-like structure, such
-   as a (possibly remote) Nix store or the contents of a NAR file. */
+/**
+ * An abstract class for accessing a filesystem-like structure, such
+ * as a (possibly remote) Nix store or the contents of a NAR file.
+ */
 class FSAccessor
 {
 public:
@@ -15,8 +17,17 @@ public:
     struct Stat
     {
         Type type = tMissing;
-        uint64_t fileSize = 0; // regular files only
+        /**
+         * regular files only
+         */
+        uint64_t fileSize = 0;
+        /**
+         * regular files only
+         */
         bool isExecutable = false; // regular files only
+        /**
+         * regular files only
+         */
         uint64_t narOffset = 0; // regular files only
     };
 
diff --git a/src/libstore/gc-store.hh b/src/libstore/gc-store.hh
index 17f043a63..2c26c65c4 100644
--- a/src/libstore/gc-store.hh
+++ b/src/libstore/gc-store.hh
@@ -12,19 +12,20 @@ typedef std::unordered_map<StorePath, std::unordered_set<std::string>> Roots;
 
 struct GCOptions
 {
-    /* Garbage collector operation:
-
-       - `gcReturnLive': return the set of paths reachable from
-         (i.e. in the closure of) the roots.
-
-       - `gcReturnDead': return the set of paths not reachable from
-         the roots.
-
-       - `gcDeleteDead': actually delete the latter set.
-
-       - `gcDeleteSpecific': delete the paths listed in
-          `pathsToDelete', insofar as they are not reachable.
-    */
+    /**
+     * Garbage collector operation:
+     *
+     * - `gcReturnLive`: return the set of paths reachable from
+     *   (i.e. in the closure of) the roots.
+     *
+     * - `gcReturnDead`: return the set of paths not reachable from
+     *   the roots.
+     *
+     * - `gcDeleteDead`: actually delete the latter set.
+     *
+     * - `gcDeleteSpecific`: delete the paths listed in
+     *    `pathsToDelete`, insofar as they are not reachable.
+     */
     typedef enum {
         gcReturnLive,
         gcReturnDead,
@@ -34,28 +35,38 @@ struct GCOptions
 
     GCAction action{gcDeleteDead};
 
-    /* If `ignoreLiveness' is set, then reachability from the roots is
-       ignored (dangerous!).  However, the paths must still be
-       unreferenced *within* the store (i.e., there can be no other
-       store paths that depend on them). */
+    /**
+     * If `ignoreLiveness` is set, then reachability from the roots is
+     * ignored (dangerous!).  However, the paths must still be
+     * unreferenced *within* the store (i.e., there can be no other
+     * store paths that depend on them).
+     */
     bool ignoreLiveness{false};
 
-    /* For `gcDeleteSpecific', the paths to delete. */
+    /**
+     * For `gcDeleteSpecific`, the paths to delete.
+     */
     StorePathSet pathsToDelete;
 
-    /* Stop after at least `maxFreed' bytes have been freed. */
+    /**
+     * Stop after at least `maxFreed` bytes have been freed.
+     */
     uint64_t maxFreed{std::numeric_limits<uint64_t>::max()};
 };
 
 
 struct GCResults
 {
-    /* Depending on the action, the GC roots, or the paths that would
-       be or have been deleted. */
+    /**
+     * Depending on the action, the GC roots, or the paths that would
+     * be or have been deleted.
+     */
     PathSet paths;
 
-    /* For `gcReturnDead', `gcDeleteDead' and `gcDeleteSpecific', the
-       number of bytes that would be or was freed. */
+    /**
+     * For `gcReturnDead`, `gcDeleteDead` and `gcDeleteSpecific`, the
+     * number of bytes that would be or was freed.
+     */
     uint64_t bytesFreed = 0;
 };
 
@@ -64,21 +75,27 @@ struct GcStore : public virtual Store
 {
     inline static std::string operationName = "Garbage collection";
 
-    /* Add an indirect root, which is merely a symlink to `path' from
-       /nix/var/nix/gcroots/auto/<hash of `path'>.  `path' is supposed
-       to be a symlink to a store path.  The garbage collector will
-       automatically remove the indirect root when it finds that
-       `path' has disappeared. */
+    /**
+     * Add an indirect root, which is merely a symlink to `path` from
+     * `/nix/var/nix/gcroots/auto/<hash of path>`.  `path` is supposed
+     * to be a symlink to a store path.  The garbage collector will
+     * automatically remove the indirect root when it finds that
+     * `path` has disappeared.
+     */
     virtual void addIndirectRoot(const Path & path) = 0;
 
-    /* Find the roots of the garbage collector.  Each root is a pair
-       (link, storepath) where `link' is the path of the symlink
-       outside of the Nix store that point to `storePath'. If
-       'censor' is true, privacy-sensitive information about roots
-       found in /proc is censored. */
+    /**
+     * Find the roots of the garbage collector.  Each root is a pair
+     * `(link, storepath)` where `link` is the path of the symlink
+     * outside of the Nix store that point to `storePath`. If
+     * `censor` is true, privacy-sensitive information about roots
+     * found in `/proc` is censored.
+     */
     virtual Roots findRoots(bool censor) = 0;
 
-    /* Perform a garbage collection. */
+    /**
+     * Perform a garbage collection.
+     */
     virtual void collectGarbage(const GCOptions & options, GCResults & results) = 0;
 };
 
diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh
index 9b04c9e78..63c7389da 100644
--- a/src/libstore/globals.hh
+++ b/src/libstore/globals.hh
@@ -72,30 +72,46 @@ public:
 
     Path nixPrefix;
 
-    /* The directory where we store sources and derived files. */
+    /**
+     * The directory where we store sources and derived files.
+     */
     Path nixStore;
 
     Path nixDataDir; /* !!! fix */
 
-    /* The directory where we log various operations. */
+    /**
+     * The directory where we log various operations.
+     */
     Path nixLogDir;
 
-    /* The directory where state is stored. */
+    /**
+     * The directory where state is stored.
+     */
     Path nixStateDir;
 
-    /* The directory where system configuration files are stored. */
+    /**
+     * The directory where system configuration files are stored.
+     */
     Path nixConfDir;
 
-    /* A list of user configuration files to load. */
+    /**
+     * A list of user configuration files to load.
+     */
     std::vector<Path> nixUserConfFiles;
 
-    /* The directory where the main programs are stored. */
+    /**
+     * The directory where the main programs are stored.
+     */
     Path nixBinDir;
 
-    /* The directory where the man pages are stored. */
+    /**
+     * The directory where the man pages are stored.
+     */
     Path nixManDir;
 
-    /* File name of the socket the daemon listens to.  */
+    /**
+     * File name of the socket the daemon listens to.
+     */
     Path nixDaemonSocketFile;
 
     Setting<std::string> storeUri{this, getEnv("NIX_REMOTE").value_or("auto"), "store",
@@ -121,7 +137,9 @@ public:
         )",
         {"build-fallback"}};
 
-    /* Whether to show build log output in real time. */
+    /**
+     * Whether to show build log output in real time.
+     */
     bool verboseBuild = true;
 
     Setting<size_t> logLines{this, 10, "log-lines",
@@ -157,8 +175,10 @@ public:
         )",
         {"build-cores"}, false};
 
-    /* Read-only mode.  Don't copy stuff to the store, don't change
-       the database. */
+    /**
+     * Read-only mode.  Don't copy stuff to the store, don't change
+     * the database.
+     */
     bool readOnlyMode = false;
 
     Setting<std::string> thisSystem{
@@ -458,7 +478,9 @@ public:
         )",
         {"env-keep-derivations"}};
 
-    /* Whether to lock the Nix client and worker to the same CPU. */
+    /**
+     * Whether to lock the Nix client and worker to the same CPU.
+     */
     bool lockCPU;
 
     Setting<SandboxMode> sandboxMode{
@@ -997,8 +1019,10 @@ public:
 // FIXME: don't use a global variable.
 extern Settings settings;
 
-/* This should be called after settings are initialized, but before
-   anything else */
+/**
+ * This should be called after settings are initialized, but before
+ * anything else
+ */
 void initPlugins();
 
 void loadConfFile();
@@ -1008,12 +1032,16 @@ std::vector<Path> getUserConfigFiles();
 
 extern const std::string nixVersion;
 
-/* NB: This is not sufficient. You need to call initNix() */
+/**
+ * NB: This is not sufficient. You need to call initNix()
+ */
 void initLibStore();
 
-/* It's important to initialize before doing _anything_, which is why we
-   call upon the programmer to handle this correctly. However, we only add
-   this in a key locations, so as not to litter the code. */
+/**
+ * It's important to initialize before doing _anything_, which is why we
+ * call upon the programmer to handle this correctly. However, we only add
+ * this in a key locations, so as not to litter the code.
+ */
 void assertLibStoreInitialized();
 
 }
diff --git a/src/libstore/local-fs-store.hh b/src/libstore/local-fs-store.hh
index 1e7f31a09..a03bb88f5 100644
--- a/src/libstore/local-fs-store.hh
+++ b/src/libstore/local-fs-store.hh
@@ -48,7 +48,9 @@ public:
     void narFromPath(const StorePath & path, Sink & sink) override;
     ref<FSAccessor> getFSAccessor() override;
 
-    /* Register a permanent GC root. */
+    /**
+     * Register a permanent GC root.
+     */
     Path addPermRoot(const StorePath & storePath, const Path & gcRoot);
 
     virtual Path getRealStoreDir() { return realStoreDir; }
diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh
index 7e0849961..55add18dd 100644
--- a/src/libstore/local-store.hh
+++ b/src/libstore/local-store.hh
@@ -19,10 +19,14 @@
 namespace nix {
 
 
-/* Nix store and database schema version.  Version 1 (or 0) was Nix <=
-   0.7.  Version 2 was Nix 0.8 and 0.9.  Version 3 is Nix 0.10.
-   Version 4 is Nix 0.11.  Version 5 is Nix 0.12-0.16.  Version 6 is
-   Nix 1.0.  Version 7 is Nix 1.3. Version 10 is 2.0. */
+/**
+ * Nix store and database schema version.
+ *
+ * Version 1 (or 0) was Nix <=
+ * 0.7.  Version 2 was Nix 0.8 and 0.9.  Version 3 is Nix 0.10.
+ * Version 4 is Nix 0.11.  Version 5 is Nix 0.12-0.16.  Version 6 is
+ * Nix 1.0.  Version 7 is Nix 1.3. Version 10 is 2.0.
+ */
 const int nixSchemaVersion = 10;
 
 
@@ -51,30 +55,40 @@ class LocalStore : public virtual LocalStoreConfig, public virtual LocalFSStore,
 {
 private:
 
-    /* Lock file used for upgrading. */
+    /**
+     * Lock file used for upgrading.
+     */
     AutoCloseFD globalLock;
 
     struct State
     {
-        /* The SQLite database object. */
+        /**
+         * The SQLite database object.
+         */
         SQLite db;
 
         struct Stmts;
         std::unique_ptr<Stmts> stmts;
 
-        /* The last time we checked whether to do an auto-GC, or an
-           auto-GC finished. */
+        /**
+         * The last time we checked whether to do an auto-GC, or an
+         * auto-GC finished.
+         */
         std::chrono::time_point<std::chrono::steady_clock> lastGCCheck;
 
-        /* Whether auto-GC is running. If so, get gcFuture to wait for
-           the GC to finish. */
+        /**
+         * Whether auto-GC is running. If so, get gcFuture to wait for
+         * the GC to finish.
+         */
         bool gcRunning = false;
         std::shared_future<void> gcFuture;
 
-        /* How much disk space was available after the previous
-           auto-GC. If the current available disk space is below
-           minFree but not much below availAfterGC, then there is no
-           point in starting a new GC. */
+        /**
+         * How much disk space was available after the previous
+         * auto-GC. If the current available disk space is below
+         * minFree but not much below availAfterGC, then there is no
+         * point in starting a new GC.
+         */
         uint64_t availAfterGC = std::numeric_limits<uint64_t>::max();
 
         std::unique_ptr<PublicKeys> publicKeys;
@@ -97,11 +111,15 @@ private:
 
 public:
 
-    // Hack for build-remote.cc.
+    /**
+     * Hack for build-remote.cc.
+     */
     PathSet locksHeld;
 
-    /* Initialise the local store, upgrading the schema if
-       necessary. */
+    /**
+     * Initialise the local store, upgrading the schema if
+     * necessary.
+     */
     LocalStore(const Params & params);
     LocalStore(std::string scheme, std::string path, const Params & params);
 
@@ -110,7 +128,9 @@ public:
     static std::set<std::string> uriSchemes()
     { return {}; }
 
-    /* Implementations of abstract store API methods. */
+    /**
+     * Implementations of abstract store API methods.
+     */
 
     std::string getUri() override;
 
@@ -155,13 +175,19 @@ private:
 
     void createTempRootsFile();
 
-    /* The file to which we write our temporary roots. */
+    /**
+     * The file to which we write our temporary roots.
+     */
     Sync<AutoCloseFD> _fdTempRoots;
 
-    /* The global GC lock. */
+    /**
+     * The global GC lock.
+     */
     Sync<AutoCloseFD> _fdGCLock;
 
-    /* Connection to the garbage collector. */
+    /**
+     * Connection to the garbage collector.
+     */
     Sync<AutoCloseFD> _fdRootsSocket;
 
 public:
@@ -180,24 +206,30 @@ public:
 
     void collectGarbage(const GCOptions & options, GCResults & results) override;
 
-    /* Optimise the disk space usage of the Nix store by hard-linking
-       files with the same contents. */
+    /**
+     * Optimise the disk space usage of the Nix store by hard-linking
+     * files with the same contents.
+     */
     void optimiseStore(OptimiseStats & stats);
 
     void optimiseStore() override;
 
-    /* Optimise a single store path. Optionally, test the encountered
-       symlinks for corruption. */
+    /**
+     * Optimise a single store path. Optionally, test the encountered
+     * symlinks for corruption.
+     */
     void optimisePath(const Path & path, RepairFlag repair);
 
     bool verifyStore(bool checkContents, RepairFlag repair) override;
 
-    /* Register the validity of a path, i.e., that `path' exists, that
-       the paths referenced by it exists, and in the case of an output
-       path of a derivation, that it has been produced by a successful
-       execution of the derivation (or something equivalent).  Also
-       register the hash of the file system contents of the path.  The
-       hash must be a SHA-256 hash. */
+    /**
+     * Register the validity of a path, i.e., that `path` exists, that
+     * the paths referenced by it exists, and in the case of an output
+     * path of a derivation, that it has been produced by a successful
+     * execution of the derivation (or something equivalent).  Also
+     * register the hash of the file system contents of the path.  The
+     * hash must be a SHA-256 hash.
+     */
     void registerValidPath(const ValidPathInfo & info);
 
     void registerValidPaths(const ValidPathInfos & infos);
@@ -212,12 +244,16 @@ public:
 
     void addSignatures(const StorePath & storePath, const StringSet & sigs) override;
 
-    /* If free disk space in /nix/store if below minFree, delete
-       garbage until it exceeds maxFree. */
+    /**
+     * If free disk space in /nix/store if below minFree, delete
+     * garbage until it exceeds maxFree.
+     */
     void autoGC(bool sync = true);
 
-    /* Register the store path 'output' as the output named 'outputName' of
-       derivation 'deriver'. */
+    /**
+     * Register the store path 'output' as the output named 'outputName' of
+     * derivation 'deriver'.
+     */
     void registerDrvOutput(const Realisation & info) override;
     void registerDrvOutput(const Realisation & info, CheckSigsFlag checkSigs) override;
     void cacheDrvOutputMapping(
@@ -247,7 +283,9 @@ private:
 
     void invalidatePath(State & state, const StorePath & path);
 
-    /* Delete a path from the Nix store. */
+    /**
+     * Delete a path from the Nix store.
+     */
     void invalidatePathChecked(const StorePath & path);
 
     void verifyPath(const Path & path, const StringSet & store,
@@ -280,8 +318,10 @@ private:
     bool isValidPath_(State & state, const StorePath & path);
     void queryReferrers(State & state, const StorePath & path, StorePathSet & referrers);
 
-    /* Add signatures to a ValidPathInfo or Realisation using the secret keys
-       specified by the ‘secret-key-files’ option. */
+    /**
+     * Add signatures to a ValidPathInfo or Realisation using the secret keys
+     * specified by the ‘secret-key-files’ option.
+     */
     void signPathInfo(ValidPathInfo & info);
     void signRealisation(Realisation &);
 
@@ -311,18 +351,23 @@ typedef std::pair<dev_t, ino_t> Inode;
 typedef std::set<Inode> InodesSeen;
 
 
-/* "Fix", or canonicalise, the meta-data of the files in a store path
-   after it has been built.  In particular:
-   - the last modification date on each file is set to 1 (i.e.,
-     00:00:01 1/1/1970 UTC)
-   - the permissions are set of 444 or 555 (i.e., read-only with or
-     without execute permission; setuid bits etc. are cleared)
-   - the owner and group are set to the Nix user and group, if we're
-     running as root.
-   If uidRange is not empty, this function will throw an error if it
-   encounters files owned by a user outside of the closed interval
-   [uidRange->first, uidRange->second].
-*/
+/**
+ * "Fix", or canonicalise, the meta-data of the files in a store path
+ * after it has been built.  In particular:
+ *
+ * - the last modification date on each file is set to 1 (i.e.,
+ *   00:00:01 1/1/1970 UTC)
+ *
+ * - the permissions are set of 444 or 555 (i.e., read-only with or
+ *   without execute permission; setuid bits etc. are cleared)
+ *
+ * - the owner and group are set to the Nix user and group, if we're
+ *   running as root.
+ *
+ * If uidRange is not empty, this function will throw an error if it
+ * encounters files owned by a user outside of the closed interval
+ * [uidRange->first, uidRange->second].
+ */
 void canonicalisePathMetaData(
     const Path & path,
     std::optional<std::pair<uid_t, uid_t>> uidRange,
diff --git a/src/libstore/lock.hh b/src/libstore/lock.hh
index 7be3ba314..1c268e1fb 100644
--- a/src/libstore/lock.hh
+++ b/src/libstore/lock.hh
@@ -13,14 +13,18 @@ struct UserLock
 {
     virtual ~UserLock() { }
 
-    /* Get the first and last UID. */
+    /**
+     * Get the first and last UID.
+     */
     std::pair<uid_t, uid_t> getUIDRange()
     {
         auto first = getUID();
         return {first, first + getUIDCount() - 1};
     }
 
-    /* Get the first UID. */
+    /**
+     * Get the first UID.
+     */
     virtual uid_t getUID() = 0;
 
     virtual uid_t getUIDCount() = 0;
@@ -30,8 +34,10 @@ struct UserLock
     virtual std::vector<gid_t> getSupplementaryGIDs() = 0;
 };
 
-/* Acquire a user lock for a UID range of size `nrIds`. Note that this
-   may return nullptr if no user is available. */
+/**
+ * Acquire a user lock for a UID range of size `nrIds`. Note that this
+ * may return nullptr if no user is available.
+ */
 std::unique_ptr<UserLock> acquireUserLock(uid_t nrIds, bool useUserNamespace);
 
 bool useBuildUsers();
diff --git a/src/libstore/log-store.hh b/src/libstore/log-store.hh
index 7aeec73b2..a84f7dbeb 100644
--- a/src/libstore/log-store.hh
+++ b/src/libstore/log-store.hh
@@ -10,8 +10,10 @@ struct LogStore : public virtual Store
 {
     inline static std::string operationName = "Build log storage and retrieval";
 
-    /* Return the build log of the specified store path, if available,
-       or null otherwise. */
+    /**
+     * Return the build log of the specified store path, if available,
+     * or null otherwise.
+     */
     std::optional<std::string> getBuildLog(const StorePath & path);
 
     virtual std::optional<std::string> getBuildLogExact(const StorePath & path) = 0;
diff --git a/src/libstore/nar-accessor.hh b/src/libstore/nar-accessor.hh
index 940e537b6..5e19bd3c7 100644
--- a/src/libstore/nar-accessor.hh
+++ b/src/libstore/nar-accessor.hh
@@ -10,24 +10,30 @@ namespace nix {
 
 struct Source;
 
-/* Return an object that provides access to the contents of a NAR
-   file. */
+/**
+ * Return an object that provides access to the contents of a NAR
+ * file.
+ */
 ref<FSAccessor> makeNarAccessor(std::string && nar);
 
 ref<FSAccessor> makeNarAccessor(Source & source);
 
-/* Create a NAR accessor from a NAR listing (in the format produced by
-   listNar()). The callback getNarBytes(offset, length) is used by the
-   readFile() method of the accessor to get the contents of files
-   inside the NAR. */
+/**
+ * Create a NAR accessor from a NAR listing (in the format produced by
+ * listNar()). The callback getNarBytes(offset, length) is used by the
+ * readFile() method of the accessor to get the contents of files
+ * inside the NAR.
+ */
 typedef std::function<std::string(uint64_t, uint64_t)> GetNarBytes;
 
 ref<FSAccessor> makeLazyNarAccessor(
     const std::string & listing,
     GetNarBytes getNarBytes);
 
-/* Write a JSON representation of the contents of a NAR (except file
-   contents). */
+/**
+ * Write a JSON representation of the contents of a NAR (except file
+ * contents).
+ */
 nlohmann::json listNar(ref<FSAccessor> accessor, const Path & path, bool recurse);
 
 }
diff --git a/src/libstore/nar-info-disk-cache.hh b/src/libstore/nar-info-disk-cache.hh
index c596f2d71..bbd1d05d5 100644
--- a/src/libstore/nar-info-disk-cache.hh
+++ b/src/libstore/nar-info-disk-cache.hh
@@ -43,8 +43,10 @@ public:
         const std::string & uri, const DrvOutput & id) = 0;
 };
 
-/* Return a singleton cache object that can be used concurrently by
-   multiple threads. */
+/**
+ * Return a singleton cache object that can be used concurrently by
+ * multiple threads.
+ */
 ref<NarInfoDiskCache> getNarInfoDiskCache();
 
 ref<NarInfoDiskCache> getTestNarInfoDiskCache(Path dbPath);
diff --git a/src/libstore/path-info.hh b/src/libstore/path-info.hh
index b28bf751c..9af1309a0 100644
--- a/src/libstore/path-info.hh
+++ b/src/libstore/path-info.hh
@@ -19,8 +19,14 @@ struct SubstitutablePathInfo
 {
     std::optional<StorePath> deriver;
     StorePathSet references;
-    uint64_t downloadSize; /* 0 = unknown or inapplicable */
-    uint64_t narSize; /* 0 = unknown */
+    /**
+     * 0 = unknown or inapplicable
+     */
+    uint64_t downloadSize;
+    /**
+     * 0 = unknown
+     */
+    uint64_t narSize;
 };
 
 typedef std::map<StorePath, SubstitutablePathInfo> SubstitutablePathInfos;
@@ -30,35 +36,40 @@ struct ValidPathInfo
 {
     StorePath path;
     std::optional<StorePath> deriver;
-    // TODO document this
+    /**
+     * \todo document this
+     */
     Hash narHash;
     StorePathSet references;
     time_t registrationTime = 0;
     uint64_t narSize = 0; // 0 = unknown
     uint64_t id; // internal use only
 
-    /* Whether the path is ultimately trusted, that is, it's a
-       derivation output that was built locally. */
+    /**
+     * Whether the path is ultimately trusted, that is, it's a
+     * derivation output that was built locally.
+     */
     bool ultimate = false;
 
     StringSet sigs; // note: not necessarily verified
 
-    /* If non-empty, an assertion that the path is content-addressed,
-       i.e., that the store path is computed from a cryptographic hash
-       of the contents of the path, plus some other bits of data like
-       the "name" part of the path. Such a path doesn't need
-       signatures, since we don't have to trust anybody's claim that
-       the path is the output of a particular derivation. (In the
-       extensional store model, we have to trust that the *contents*
-       of an output path of a derivation were actually produced by
-       that derivation. In the intensional model, we have to trust
-       that a particular output path was produced by a derivation; the
-       path then implies the contents.)
-
-       Ideally, the content-addressability assertion would just be a Boolean,
-       and the store path would be computed from the name component, ‘narHash’
-       and ‘references’. However, we support many types of content addresses.
-    */
+    /**
+     * If non-empty, an assertion that the path is content-addressed,
+     * i.e., that the store path is computed from a cryptographic hash
+     * of the contents of the path, plus some other bits of data like
+     * the "name" part of the path. Such a path doesn't need
+     * signatures, since we don't have to trust anybody's claim that
+     * the path is the output of a particular derivation. (In the
+     * extensional store model, we have to trust that the *contents*
+     * of an output path of a derivation were actually produced by
+     * that derivation. In the intensional model, we have to trust
+     * that a particular output path was produced by a derivation; the
+     * path then implies the contents.)
+     *
+     * Ideally, the content-addressability assertion would just be a Boolean,
+     * and the store path would be computed from the name component, ‘narHash’
+     * and ‘references’. However, we support many types of content addresses.
+     */
     std::optional<ContentAddress> ca;
 
     bool operator == (const ValidPathInfo & i) const
@@ -69,27 +80,35 @@ struct ValidPathInfo
             && references == i.references;
     }
 
-    /* Return a fingerprint of the store path to be used in binary
-       cache signatures. It contains the store path, the base-32
-       SHA-256 hash of the NAR serialisation of the path, the size of
-       the NAR, and the sorted references. The size field is strictly
-       speaking superfluous, but might prevent endless/excessive data
-       attacks. */
+    /**
+     * Return a fingerprint of the store path to be used in binary
+     * cache signatures. It contains the store path, the base-32
+     * SHA-256 hash of the NAR serialisation of the path, the size of
+     * the NAR, and the sorted references. The size field is strictly
+     * speaking superfluous, but might prevent endless/excessive data
+     * attacks.
+     */
     std::string fingerprint(const Store & store) const;
 
     void sign(const Store & store, const SecretKey & secretKey);
 
-    /* Return true iff the path is verifiably content-addressed. */
+    /**
+     * @return true iff the path is verifiably content-addressed.
+     */
     bool isContentAddressed(const Store & store) const;
 
     static const size_t maxSigs = std::numeric_limits<size_t>::max();
 
-    /* Return the number of signatures on this .narinfo that were
-       produced by one of the specified keys, or maxSigs if the path
-       is content-addressed. */
+    /**
+     * Return the number of signatures on this .narinfo that were
+     * produced by one of the specified keys, or maxSigs if the path
+     * is content-addressed.
+     */
     size_t checkSignatures(const Store & store, const PublicKeys & publicKeys) const;
 
-    /* Verify a single signature. */
+    /**
+     * Verify a single signature.
+     */
     bool checkSignature(const Store & store, const PublicKeys & publicKeys, const std::string & sig) const;
 
     Strings shortRefs() const;
diff --git a/src/libstore/path-with-outputs.hh b/src/libstore/path-with-outputs.hh
index a845b0e5f..d75850868 100644
--- a/src/libstore/path-with-outputs.hh
+++ b/src/libstore/path-with-outputs.hh
@@ -6,13 +6,14 @@
 
 namespace nix {
 
-/* This is a deprecated old type just for use by the old CLI, and older
-   versions of the RPC protocols. In new code don't use it; you want
-   `DerivedPath` instead.
-
-   `DerivedPath` is better because it handles more cases, and does so more
-   explicitly without devious punning tricks.
-*/
+/**
+ * This is a deprecated old type just for use by the old CLI, and older
+ * versions of the RPC protocols. In new code don't use it; you want
+ * `DerivedPath` instead.
+ *
+ * `DerivedPath` is better because it handles more cases, and does so more
+ * explicitly without devious punning tricks.
+ */
 struct StorePathWithOutputs
 {
     StorePath path;
@@ -31,9 +32,11 @@ std::pair<std::string_view, StringSet> parsePathWithOutputs(std::string_view s);
 
 class Store;
 
-/* Split a string specifying a derivation and a set of outputs
-   (/nix/store/hash-foo!out1,out2,...) into the derivation path
-   and the outputs. */
+/**
+ * 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 parsePathWithOutputs(const Store & store, std::string_view pathWithOutputs);
 
 StorePathWithOutputs followLinksToStorePathWithOutputs(const Store & store, std::string_view pathWithOutputs);
diff --git a/src/libstore/pathlocks.hh b/src/libstore/pathlocks.hh
index ba8f2749b..4921df352 100644
--- a/src/libstore/pathlocks.hh
+++ b/src/libstore/pathlocks.hh
@@ -5,12 +5,16 @@
 
 namespace nix {
 
-/* Open (possibly create) a lock file and return the file descriptor.
-   -1 is returned if create is false and the lock could not be opened
-   because it doesn't exist.  Any other error throws an exception. */
+/**
+ * Open (possibly create) a lock file and return the file descriptor.
+ * -1 is returned if create is false and the lock could not be opened
+ * because it doesn't exist.  Any other error throws an exception.
+ */
 AutoCloseFD openLockFile(const Path & path, bool create);
 
-/* Delete an open lock file. */
+/**
+ * Delete an open lock file.
+ */
 void deleteLockFile(const Path & path, int fd);
 
 enum LockType { ltRead, ltWrite, ltNone };
diff --git a/src/libstore/profiles.hh b/src/libstore/profiles.hh
index 6a5965390..4e1f42e83 100644
--- a/src/libstore/profiles.hh
+++ b/src/libstore/profiles.hh
@@ -1,7 +1,7 @@
 #pragma once
 ///@file
 
-#include "types.hh"
+ #include "types.hh"
 #include "pathlocks.hh"
 
 #include <time.h>
@@ -24,9 +24,11 @@ struct Generation
 typedef std::list<Generation> Generations;
 
 
-/* Returns the list of currently present generations for the specified
-   profile, sorted by generation number. Also returns the number of
-   the current generation. */
+/**
+ * Returns the list of currently present generations for the specified
+ * profile, sorted by generation number. Also returns the number of
+ * the current generation.
+ */
 std::pair<Generations, std::optional<GenerationNumber>> findGenerations(Path profile);
 
 class LocalFSStore;
@@ -47,26 +49,32 @@ void deleteGenerationsOlderThan(const Path & profile, std::string_view timeSpec,
 
 void switchLink(Path link, Path target);
 
-/* Roll back a profile to the specified generation, or to the most
-   recent one older than the current. */
+/**
+ * Roll back a profile to the specified generation, or to the most
+ * recent one older than the current.
+ */
 void switchGeneration(
     const Path & profile,
     std::optional<GenerationNumber> dstGen,
     bool dryRun);
 
-/* Ensure exclusive access to a profile.  Any command that modifies
-   the profile first acquires this lock. */
+/**
+ * Ensure exclusive access to a profile.  Any command that modifies
+ * the profile first acquires this lock.
+ */
 void lockProfile(PathLocks & lock, const Path & profile);
 
-/* Optimistic locking is used by long-running operations like `nix-env
-   -i'.  Instead of acquiring the exclusive lock for the entire
-   duration of the operation, we just perform the operation
-   optimistically (without an exclusive lock), and check at the end
-   whether the profile changed while we were busy (i.e., the symlink
-   target changed).  If so, the operation is restarted.  Restarting is
-   generally cheap, since the build results are still in the Nix
-   store.  Most of the time, only the user environment has to be
-   rebuilt. */
+/**
+ * Optimistic locking is used by long-running operations like `nix-env
+ * -i'.  Instead of acquiring the exclusive lock for the entire
+ * duration of the operation, we just perform the operation
+ * optimistically (without an exclusive lock), and check at the end
+ * whether the profile changed while we were busy (i.e., the symlink
+ * target changed).  If so, the operation is restarted.  Restarting is
+ * generally cheap, since the build results are still in the Nix
+ * store.  Most of the time, only the user environment has to be
+ * rebuilt.
+ */
 std::string optimisticLockProfile(const Path & profile);
 
 /**
diff --git a/src/libstore/remote-store.hh b/src/libstore/remote-store.hh
index f220dbc20..1c45f543e 100644
--- a/src/libstore/remote-store.hh
+++ b/src/libstore/remote-store.hh
@@ -32,8 +32,10 @@ struct RemoteStoreConfig : virtual StoreConfig
         "Maximum age of a connection before it is closed."};
 };
 
-/* FIXME: RemoteStore is a misnomer - should be something like
-   DaemonStore. */
+/**
+ * \todo RemoteStore is a misnomer - should be something like
+ * DaemonStore.
+ */
 class RemoteStore : public virtual RemoteStoreConfig,
     public virtual Store,
     public virtual GcStore,
@@ -69,7 +71,9 @@ public:
     void querySubstitutablePathInfos(const StorePathCAMap & paths,
         SubstitutablePathInfos & infos) override;
 
-    /* Add a content-addressable store path. `dump` will be drained. */
+    /**
+     * Add a content-addressable store path. `dump` will be drained.
+     */
     ref<const ValidPathInfo> addCAToStore(
         Source & dump,
         std::string_view name,
@@ -77,7 +81,9 @@ public:
         const StorePathSet & references,
         RepairFlag repair);
 
-    /* Add a content-addressable store path. Does not support references. `dump` will be drained. */
+    /**
+     * Add a content-addressable store path. Does not support references. `dump` will be drained.
+     */
     StorePath addToStoreFromDump(Source & dump, std::string_view name,
         FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair, const StorePathSet & references = StorePathSet()) override;
 
diff --git a/src/libstore/sqlite.hh b/src/libstore/sqlite.hh
index 86410f998..b735838ec 100644
--- a/src/libstore/sqlite.hh
+++ b/src/libstore/sqlite.hh
@@ -11,7 +11,9 @@ struct sqlite3_stmt;
 
 namespace nix {
 
-/* RAII wrapper to close a SQLite database automatically. */
+/**
+ * RAII wrapper to close a SQLite database automatically.
+ */
 struct SQLite
 {
     sqlite3 * db = 0;
@@ -23,7 +25,9 @@ struct SQLite
     ~SQLite();
     operator sqlite3 * () { return db; }
 
-    /* Disable synchronous mode, set truncate journal mode. */
+    /**
+     * Disable synchronous mode, set truncate journal mode.
+     */
     void isCache();
 
     void exec(const std::string & stmt);
@@ -31,7 +35,9 @@ struct SQLite
     uint64_t getLastInsertedRowId();
 };
 
-/* RAII wrapper to create and destroy SQLite prepared statements. */
+/**
+ * RAII wrapper to create and destroy SQLite prepared statements.
+ */
 struct SQLiteStmt
 {
     sqlite3 * db = 0;
@@ -43,7 +49,9 @@ struct SQLiteStmt
     ~SQLiteStmt();
     operator sqlite3_stmt * () { return stmt; }
 
-    /* Helper for binding / executing statements. */
+    /**
+     * Helper for binding / executing statements.
+     */
     class Use
     {
         friend struct SQLiteStmt;
@@ -56,7 +64,9 @@ struct SQLiteStmt
 
         ~Use();
 
-        /* Bind the next parameter. */
+        /**
+         * Bind the next parameter.
+         */
         Use & operator () (std::string_view value, bool notNull = true);
         Use & operator () (const unsigned char * data, size_t len, bool notNull = true);
         Use & operator () (int64_t value, bool notNull = true);
@@ -64,11 +74,15 @@ struct SQLiteStmt
 
         int step();
 
-        /* Execute a statement that does not return rows. */
+        /**
+         * Execute a statement that does not return rows.
+         */
         void exec();
 
-        /* For statements that return 0 or more rows. Returns true iff
-           a row is available. */
+        /**
+         * For statements that return 0 or more rows. Returns true iff
+         * a row is available.
+         */
         bool next();
 
         std::string getStr(int col);
@@ -82,8 +96,10 @@ struct SQLiteStmt
     }
 };
 
-/* RAII helper that ensures transactions are aborted unless explicitly
-   committed. */
+/**
+ * RAII helper that ensures transactions are aborted unless explicitly
+ * committed.
+ */
 struct SQLiteTxn
 {
     bool active = false;
@@ -125,8 +141,10 @@ MakeError(SQLiteBusy, SQLiteError);
 
 void handleSQLiteBusy(const SQLiteBusy & e);
 
-/* Convenience function for retrying a SQLite transaction when the
-   database is busy. */
+/**
+ * Convenience function for retrying a SQLite transaction when the
+ * database is busy.
+ */
 template<typename T, typename F>
 T retrySQLite(F && fun)
 {
diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index 9c6e80486..3cb48bff5 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -411,17 +411,17 @@ public:
     { unsupported("queryReferrers"); }
 
     /**
-     * @return all currently valid derivations that have `path' as an
+     * @return all currently valid derivations that have `path` as an
      * output.
      *
-     * (Note that the result of `queryDeriver()' is the derivation that
-     * was actually used to produce `path', which may not exist
+     * (Note that the result of `queryDeriver()` is the derivation that
+     * was actually used to produce `path`, which may not exist
      * anymore.)
      */
     virtual StorePathSet queryValidDerivers(const StorePath & path) { return {}; };
 
     /**
-     * Query the outputs of the derivation denoted by `path'.
+     * Query the outputs of the derivation denoted by `path`.
      */
     virtual StorePathSet queryDerivationOutputs(const StorePath & path);
 
@@ -513,7 +513,7 @@ public:
 
     /**
      * Like addToStore(), but the contents of the path are contained
-     * in `dump', which is either a NAR serialisation (if recursive ==
+     * in `dump`, which is either a NAR serialisation (if recursive ==
      * true) or simply the contents of a regular file (if recursive ==
      * false).
      * `dump` may be drained
@@ -634,8 +634,8 @@ public:
 
     /**
      * @return a string representing information about the path that
-     * can be loaded into the database using `nix-store --load-db' or
-     * `nix-store --register-validity'.
+     * can be loaded into the database using `nix-store --load-db` or
+     * `nix-store --register-validity`.
      */
     std::string makeValidityRegistration(const StorePathSet & paths,
         bool showDerivers, bool showHash);
@@ -715,12 +715,12 @@ public:
 
     /**
      * @param [out] out Place in here the set of all store paths in the
-     * file system closure of `storePath'; that is, all paths than can
-     * be directly or indirectly reached from it. `out' is not cleared.
+     * file system closure of `storePath`; that is, all paths than can
+     * be directly or indirectly reached from it. `out` is not cleared.
      *
      * @param flipDirection If true, the set of paths that can reach
-     * `storePath' is returned; that is, the closures under the
-     * `referrers' relation instead of the `references' relation is
+     * `storePath` is returned; that is, the closures under the
+     * `referrers` relation instead of the `references` relation is
      * returned.
      */
     virtual void computeFSClosure(const StorePathSet & paths,