10 files changed, 60 insertions, 30 deletions
diff --git a/src/libutil/archive.cc b/src/libutil/archive.cc
index 4b0636129..0e2b9d12c 100644
--- a/src/libutil/archive.cc
+++ b/src/libutil/archive.cc
@@ -35,10 +35,6 @@ static ArchiveSettings archiveSettings;
 
 static GlobalConfig::Register rArchiveSettings(&archiveSettings);
 
-const std::string narVersionMagic1 = "nix-archive-1";
-
-static std::string caseHackSuffix = "~nix~case~hack~";
-
 PathFilter defaultPathFilter = [](const Path &) { return true; };
 
 
diff --git a/src/libutil/archive.hh b/src/libutil/archive.hh
index ac4183bf5..e42dea540 100644
--- a/src/libutil/archive.hh
+++ b/src/libutil/archive.hh
@@ -103,7 +103,9 @@ void copyNAR(Source & source, Sink & sink);
 void copyPath(const Path & from, const Path & to);
 
 
-extern const std::string narVersionMagic1;
+inline constexpr std::string_view narVersionMagic1 = "nix-archive-1";
+
+inline constexpr std::string_view caseHackSuffix = "~nix~case~hack~";
 
 
 }
diff --git a/src/libutil/fmt.hh b/src/libutil/fmt.hh
index 7664e5c04..e879fd3b8 100644
--- a/src/libutil/fmt.hh
+++ b/src/libutil/fmt.hh
@@ -148,7 +148,7 @@ inline hintformat hintfmt(const std::string & fs, const Args & ... args)
     return f;
 }
 
-inline hintformat hintfmt(std::string plain_string)
+inline hintformat hintfmt(const std::string & plain_string)
 {
     // we won't be receiving any args in this case, so just print the original string
     return hintfmt("%s", normaltxt(plain_string));
diff --git a/src/libutil/logging.cc b/src/libutil/logging.cc
index cb2b15b41..ac86d8ac2 100644
--- a/src/libutil/logging.cc
+++ b/src/libutil/logging.cc
@@ -105,14 +105,6 @@ public:
 
 Verbosity verbosity = lvlInfo;
 
-void warnOnce(bool & haveWarned, const FormatOrString & fs)
-{
-    if (!haveWarned) {
-        warn(fs.s);
-        haveWarned = true;
-    }
-}
-
 void writeToStderr(std::string_view s)
 {
     try {
@@ -130,11 +122,11 @@ Logger * makeSimpleLogger(bool printBuildLogs)
     return new SimpleLogger(printBuildLogs);
 }
 
-std::atomic<uint64_t> nextId{(uint64_t) getpid() << 32};
+std::atomic<uint64_t> nextId{0};
 
 Activity::Activity(Logger & logger, Verbosity lvl, ActivityType type,
     const std::string & s, const Logger::Fields & fields, ActivityId parent)
-    : logger(logger), id(nextId++)
+    : logger(logger), id(nextId++ + (((uint64_t) getpid()) << 32))
 {
     logger.startActivity(id, lvl, type, s, fields, parent);
 }
diff --git a/src/libutil/logging.hh b/src/libutil/logging.hh
index d0817b4a9..4642c49f7 100644
--- a/src/libutil/logging.hh
+++ b/src/libutil/logging.hh
@@ -82,7 +82,7 @@ public:
         log(lvlInfo, fs);
     }
 
-    virtual void logEI(const ErrorInfo &ei) = 0;
+    virtual void logEI(const ErrorInfo & ei) = 0;
 
     void logEI(Verbosity lvl, ErrorInfo ei)
     {
@@ -225,7 +225,11 @@ inline void warn(const std::string & fs, const Args & ... args)
     logger->warn(f.str());
 }
 
-void warnOnce(bool & haveWarned, const FormatOrString & fs);
+#define warnOnce(haveWarned, args...) \
+    if (!haveWarned) {                \
+        haveWarned = true;            \
+        warn(args);                   \
+    }
 
 void writeToStderr(std::string_view s);
 
diff --git a/src/libutil/ref.hh b/src/libutil/ref.hh
index bf26321db..7d38b059c 100644
--- a/src/libutil/ref.hh
+++ b/src/libutil/ref.hh
@@ -83,6 +83,11 @@ public:
         return p != other.p;
     }
 
+    bool operator < (const ref<T> & other) const
+    {
+        return p < other.p;
+    }
+
 private:
 
     template<typename T2, typename... Args>
diff --git a/src/libutil/serialise.cc b/src/libutil/serialise.cc
index 2c3597775..c653db9d0 100644
--- a/src/libutil/serialise.cc
+++ b/src/libutil/serialise.cc
@@ -338,7 +338,7 @@ Sink & operator << (Sink & sink, const StringSet & s)
 
 Sink & operator << (Sink & sink, const Error & ex)
 {
-    auto info = ex.info();
+    auto & info = ex.info();
     sink
         << "Error"
         << info.level
diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh
index 84847835a..7da5b07fd 100644
--- a/src/libutil/serialise.hh
+++ b/src/libutil/serialise.hh
@@ -331,17 +331,9 @@ T readNum(Source & source)
     unsigned char buf[8];
     source((char *) buf, sizeof(buf));
 
-    uint64_t n =
-        ((uint64_t) buf[0]) |
-        ((uint64_t) buf[1] << 8) |
-        ((uint64_t) buf[2] << 16) |
-        ((uint64_t) buf[3] << 24) |
-        ((uint64_t) buf[4] << 32) |
-        ((uint64_t) buf[5] << 40) |
-        ((uint64_t) buf[6] << 48) |
-        ((uint64_t) buf[7] << 56);
-
-    if (n > (uint64_t)std::numeric_limits<T>::max())
+    auto n = readLittleEndian<uint64_t>(buf);
+
+    if (n > (uint64_t) std::numeric_limits<T>::max())
         throw SerialisationError("serialised integer %d is too large for type '%s'", n, typeid(T).name());
 
     return (T) n;
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 4f2caaa40..993dc1cb6 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -1594,6 +1594,21 @@ std::string stripIndentation(std::string_view s)
 }
 
 
+std::pair<std::string_view, std::string_view> getLine(std::string_view s)
+{
+    auto newline = s.find('\n');
+
+    if (newline == s.npos) {
+        return {s, ""};
+    } else {
+        auto line = s.substr(0, newline);
+        if (!line.empty() && line[line.size() - 1] == '\r')
+            line = line.substr(0, line.size() - 1);
+        return {line, s.substr(newline + 1)};
+    }
+}
+
+
 //////////////////////////////////////////////////////////////////////
 
 static Sync<std::pair<unsigned short, unsigned short>> windowSize{{0, 0}};
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index 94d8cc555..3caa95fca 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -510,6 +510,17 @@ std::optional<N> string2Float(const std::string_view s)
 }
 
 
+/* Convert a little-endian integer to host order. */
+template<typename T>
+T readLittleEndian(unsigned char * p)
+{
+    T x = 0;
+    for (size_t i = 0; i < sizeof(x); ++i)
+        x |= ((T) *p++) << (i * 8);
+    return x;
+}
+
+
 /* Return true iff `s' starts with `prefix'. */
 bool hasPrefix(std::string_view s, std::string_view prefix);
 
@@ -563,6 +574,12 @@ std::string base64Decode(std::string_view s);
 std::string stripIndentation(std::string_view s);
 
 
+/* Get the prefix of 's' up to and excluding the next line break (LF
+   optionally preceded by CR), and the remainder following the line
+   break. */
+std::pair<std::string_view, std::string_view> getLine(std::string_view s);
+
+
 /* Get a value for the specified key from an associate container. */
 template <class T>
 const typename T::mapped_type * get(const T & map, const typename T::key_type & key)
@@ -737,4 +754,11 @@ inline std::string operator + (std::string && s, std::string_view s2)
     return std::move(s);
 }
 
+inline std::string operator + (std::string_view s1, const char * s2)
+{
+    std::string s(s1);
+    s.append(s2);
+    return s;
+}
+
 }