Merge changes I0fc80718,Ia182b86f,I355f82cb,I8a9b58fa,Id89f8a1f, ... into main

* changes:
  tree-wide: fix various lint warnings
  flake & doxygen: update tagline
  nix flake metadata: print modified dates for input flakes
  cli: eat terminal codes from stdout also
  Implement forcing CLI colour on, and document it better
  manual: fix a syntax error in redirects.js that made it not do anything
  misc docs/meson tidying
  build: implement clang-tidy using our plugin

src/libexpr/flake/config.cc

@@ -53,7 +53,7 @@ void ConfigFile::apply()
 
         bool trusted = whitelist.count(baseName);
         if (!trusted) {
-            switch (nix::fetchSettings.acceptFlakeConfig) {
+            switch (nix::fetchSettings.acceptFlakeConfig.get()) {
             case AcceptFlakeConfig::True: {
                 trusted = true;
                 break;

src/libexpr/parser/parser.cc

@@ -12,7 +12,6 @@
 #include "state.hh"
 
 #include <charconv>
-#include <clocale>
 #include <memory>
 
 // flip this define when doing parser development to enable some g checks.
@@ -254,7 +253,8 @@ struct AttrState : SubexprState {
 
     std::vector<AttrName> attrs;
 
-    void pushAttr(auto && attr, PosIdx) { attrs.emplace_back(std::move(attr)); }
+    template <typename T>
+    void pushAttr(T && attr, PosIdx) { attrs.emplace_back(std::forward<T>(attr)); }
 };
 
 template<> struct BuildAST<grammar::attr::simple> {
@@ -290,7 +290,8 @@ struct InheritState : SubexprState {
     std::unique_ptr<Expr> from;
     PosIdx fromPos;
 
-    void pushAttr(auto && attr, PosIdx pos) { attrs.emplace_back(std::move(attr), pos); }
+    template <typename T>
+    void pushAttr(T && attr, PosIdx pos) { attrs.emplace_back(std::forward<T>(attr), pos); }
 };
 
 template<> struct BuildAST<grammar::inherit::from> {

src/libstore/filetransfer.cc

@@ -477,8 +477,17 @@ struct curlFileTransfer : public FileTransfer
 
     ~curlFileTransfer()
     {
-        stopWorkerThread();
-
+        try {
+            stopWorkerThread();
+        } catch (nix::Error e) {
+            // This can only fail if a socket to our own process cannot be
+            // written to, so it is always a bug in the program if it fails.
+            //
+            // Joining the thread would probably only cause a deadlock if this
+            // happened, so just die on purpose.
+            printError("failed to join curl file transfer worker thread: %1%", e.what());
+            std::terminate();
+        }
         workerThread.join();
 
         if (curlm) curl_multi_cleanup(curlm);

src/libstore/machines.cc

@@ -33,7 +33,7 @@ Machine::Machine(decltype(storeUri) storeUri,
     systemTypes(systemTypes),
     sshKey(sshKey),
     maxJobs(maxJobs),
-    speedFactor(speedFactor == 0.0f ? 1.0f : std::move(speedFactor)),
+    speedFactor(speedFactor == 0.0f ? 1.0f : speedFactor),
     supportedFeatures(supportedFeatures),
     mandatoryFeatures(mandatoryFeatures),
     sshPublicHostKey(sshPublicHostKey)

src/libutil/archive.cc

@@ -192,7 +192,7 @@ static Generator<Entry> parseObject(Source & source, const Path & path)
 #define EXPECT(raw, kind)                              \
     do {                                               \
         const auto s = readString(source);             \
-        if (s != raw) {                                \
+        if (s != (raw)) {                                \
             throw badArchive("expected " kind " tag"); \
         }                                              \
         co_yield MetadataString{s};                    \

src/libutil/file-descriptor.cc

@@ -131,7 +131,7 @@ AutoCloseFD::AutoCloseFD(AutoCloseFD && that) : fd{that.fd}
 }
 
 
-AutoCloseFD & AutoCloseFD::operator =(AutoCloseFD && that)
+AutoCloseFD & AutoCloseFD::operator =(AutoCloseFD && that) noexcept(false)
 {
     close();
     fd = that.fd;

src/libutil/hash.cc

@@ -229,7 +229,7 @@ Hash::Hash(std::string_view rest, HashType type, bool isSRI)
 
         for (unsigned int n = 0; n < rest.size(); ++n) {
             char c = rest[rest.size() - n - 1];
-            unsigned char digit;
+            size_t digit;
             for (digit = 0; digit < base32Chars.size(); ++digit) /* !!! slow */
                 if (base32Chars[digit] == c) break;
             if (digit >= 32)

src/libutil/logging.cc

@@ -37,7 +37,7 @@ void Logger::warn(const std::string & msg)
 
 void Logger::writeToStdout(std::string_view s)
 {
-    writeFull(STDOUT_FILENO, s);
+    writeFull(STDOUT_FILENO, filterANSIEscapes(s, !shouldANSI(), std::numeric_limits<unsigned int>::max(), false));
     writeFull(STDOUT_FILENO, "\n");
 }
 

src/libutil/shlex.cc

@@ -62,6 +62,8 @@ std::vector<std::string> shell_split(const std::string & input)
                 begin = ++iterator;
             }
             break;
+            // no other relevant cases; silence exhaustiveness compiler warning
+            default: break;
         }
     }
 

src/libutil/terminal.cc

@@ -9,12 +9,25 @@ namespace nix {
 
 bool shouldANSI()
 {
-    return isatty(STDERR_FILENO)
-        && getEnv("TERM").value_or("dumb") != "dumb"
-        && !(getEnv("NO_COLOR").has_value() || getEnv("NOCOLOR").has_value());
+    // Implements the behaviour described by https://bixense.com/clicolors/
+    // As well as https://force-color.org/ for compatibility, since it fits in the same shape.
+    // NO_COLOR CLICOLOR CLICOLOR_FORCE Colours?
+    // set      x        x              No
+    // unset    x        set            Yes
+    // unset    x        unset          If attached to a terminal
+    //                                  [we choose the "modern" approach of colour-by-default]
+    auto compute = []() -> bool {
+        bool mustNotColour = getEnv("NO_COLOR").has_value() || getEnv("NOCOLOR").has_value();
+        bool shouldForce = getEnv("CLICOLOR_FORCE").has_value() || getEnv("FORCE_COLOR").has_value();
+        bool isTerminal = isatty(STDERR_FILENO) && getEnv("TERM").value_or("dumb") != "dumb";
+        return !mustNotColour && (shouldForce || isTerminal);
+    };
+    static bool cached = compute();
+    return cached;
 }
 
-std::string filterANSIEscapes(std::string_view s, bool filterAll, unsigned int width)
+// FIXME(jade): replace with TerminalCodeEater. wowie this is evil code.
+std::string filterANSIEscapes(std::string_view s, bool filterAll, unsigned int width, bool eatTabs)
 {
     std::string t, e;
     size_t w = 0;
@@ -43,7 +56,7 @@ std::string filterANSIEscapes(std::string_view s, bool filterAll, unsigned int w
                 t += e;
         }
 
-        else if (*i == '\t') {
+        else if (*i == '\t' && eatTabs) {
             i++; t += ' '; w++;
             while (w < (size_t) width && w % 8) {
                 t += ' '; w++;

src/libutil/terminal.hh

@@ -9,6 +9,15 @@ namespace nix {
 /**
  * Determine whether ANSI escape sequences are appropriate for the
  * present output.
+ *
+ * This follows the rules described on https://bixense.com/clicolors/
+ * with CLICOLOR defaulted to enabled (and thus ignored).
+ *
+ * That is to say, the following procedure is followed in order:
+ * - NO_COLOR or NOCOLOR set             -> always disable colour
+ * - CLICOLOR_FORCE or FORCE_COLOR set   -> enable colour
+ * - The output is a tty; TERM != "dumb" -> enable colour
+ * - Otherwise                           -> disable colour
  */
 bool shouldANSI();
 
@@ -21,7 +30,8 @@ bool shouldANSI();
  */
 std::string filterANSIEscapes(std::string_view s,
     bool filterAll = false,
-    unsigned int width = std::numeric_limits<unsigned int>::max());
+    unsigned int width = std::numeric_limits<unsigned int>::max(),
+    bool eatTabs = true);
 
 /**
  * Recalculate the window size, updating a global variable. Used in the

src/libutil/url.cc

@@ -63,7 +63,7 @@ std::string percentDecode(std::string_view in)
             if (i + 2 >= in.size())
                 throw BadURL("invalid URI parameter '%s'", in);
             try {
-                decoded += std::stoul(std::string(in, i + 1, 2), 0, 16);
+                decoded += char8_t(std::stoul(std::string(in, i + 1, 2), 0, 16));
                 i += 3;
             } catch (...) {
                 throw BadURL("invalid URI parameter '%s'", in);

src/nix/flake.cc

@@ -209,6 +209,11 @@ struct CmdFlakeMetadata : FlakeCommand, MixJSON
     {
         auto lockedFlake = lockFlake();
         auto & flake = lockedFlake.flake;
+        auto formatTime = [](time_t time) -> std::string {
+            std::ostringstream os{};
+            os << std::put_time(std::localtime(&time), "%F %T");
+            return os.str();
+        };
 
         if (json) {
             nlohmann::json j;
@@ -260,7 +265,7 @@ struct CmdFlakeMetadata : FlakeCommand, MixJSON
             if (auto lastModified = flake.lockedRef.input.getLastModified())
                 logger->cout(
                     ANSI_BOLD "Last modified:" ANSI_NORMAL " %s",
-                    std::put_time(std::localtime(&*lastModified), "%F %T"));
+                    formatTime(*lastModified));
 
             if (!lockedFlake.lockFile.root->inputs.empty())
                 logger->cout(ANSI_BOLD "Inputs:" ANSI_NORMAL);
@@ -275,16 +280,25 @@ struct CmdFlakeMetadata : FlakeCommand, MixJSON
                     bool last = i + 1 == node.inputs.size();
 
                     if (auto lockedNode = std::get_if<0>(&input.second)) {
-                        logger->cout("%s" ANSI_BOLD "%s" ANSI_NORMAL ": %s",
-                            prefix + (last ? treeLast : treeConn), input.first,
+                        // ├───agenix: github:ryantm/agenix/8d37c5bdeade12b6479c85acd133063ab53187a0
+                        logger->cout("%s%s" ANSI_BOLD "%s" ANSI_NORMAL ": %s",
+                            prefix, last ? treeLast : treeConn, input.first,
                             (*lockedNode)->lockedRef);
 
+                        // ├───lix: https://git.lix.systems/api/v1/repos/lix-project <....>
+                        // │   Last modified: 2024-07-31 21:01:34
+                        if (auto lastModified = (*lockedNode)->lockedRef.input.getLastModified()) {
+                            logger->cout("%s%s" ANSI_BOLD "%s" ANSI_NORMAL ": %s",
+                                prefix, last ? treeNull : treeLine, "Last modified", formatTime(*lastModified));
+                        }
+
                         bool firstVisit = visited.insert(*lockedNode).second;
 
                         if (firstVisit) recurse(**lockedNode, prefix + (last ? treeNull : treeLine));
                     } else if (auto follows = std::get_if<1>(&input.second)) {
-                        logger->cout("%s" ANSI_BOLD "%s" ANSI_NORMAL " follows input '%s'",
-                            prefix + (last ? treeLast : treeConn), input.first,
+                        // │   ├───darwin follows input 'flake-utils'
+                        logger->cout("%s%s" ANSI_BOLD "%s" ANSI_NORMAL " follows input '%s'",
+                            prefix, last ? treeLast : treeConn, input.first,
                             printInputPath(*follows));
                     }
                 }

src/nix/meson.build

@@ -1,8 +1,8 @@
-generate_manpage_gen = gen_header.process(meson.project_source_root() / 'doc/manual/generate-manpage.nix')
-
-utils_gen = gen_header.process(meson.project_source_root() / 'doc/manual/utils.nix')
-
-get_env_gen = gen_header.process('get-env.sh')
+nix_generated_headers = [
+  gen_header.process(meson.project_source_root() / 'doc/manual/generate-manpage.nix'),
+  gen_header.process(meson.project_source_root() / 'doc/manual/utils.nix'),
+  gen_header.process('get-env.sh'),
+]
 
 # src/nix/profile.cc includes src/nix/profile.md, which includes "doc/files/profiles.md.gen.hh".
 # Unfortunately, https://github.com/mesonbuild/meson/issues/2320.
@@ -18,7 +18,7 @@ run_command(
   meson.current_build_dir() / 'doc/files/profiles.md',
   check : true,
 )
-profiles_md_gen = gen_header.process(
+nix_generated_headers += gen_header.process(
   meson.current_build_dir() / 'doc/files/profiles.md',
   preserve_path_from : meson.current_build_dir(),
 )
@@ -74,10 +74,7 @@ nix_sources = files(
 nix = executable(
   'nix',
   nix_sources,
-  generate_manpage_gen,
-  utils_gen,
-  get_env_gen,
-  profiles_md_gen,
+  nix_generated_headers,
   nix2_commands_sources,
   dependencies : [
     libasanoptions,