Merge changes Ic0dfcfe2,Ibe73851f,Ia7a8df1c,I400b2031 into main

* changes:
  package.nix: remove dead code
  diff-closures: remove gratuitous copy
  tree-wide: NULL -> nullptr
  libutil: rip out GNU Hurd support code

package.nix

@@ -92,31 +92,19 @@ let
 
   # Reimplementation of Nixpkgs' Meson cross file, with some additions to make
   # it actually work.
-  mesonCrossFile =
+  mesonCrossFile = builtins.toFile "lix-cross-file.conf" ''
-    let
+    [properties]
-      cpuFamily =
+    # Meson is convinced that if !buildPlatform.canExecute hostPlatform then we cannot
-        platform:
+    # build anything at all, which is not at all correct. If we can't execute the host
-        with platform;
+    # platform, we'll just disable tests and doc gen.
-        if isAarch32 then
+    needs_exe_wrapper = false
-          "arm"
-        else if isx86_32 then
-          "x86"
-        else
-          platform.uname.processor;
-    in
-    builtins.toFile "lix-cross-file.conf" ''
-      [properties]
-      # Meson is convinced that if !buildPlatform.canExecute hostPlatform then we cannot
-      # build anything at all, which is not at all correct. If we can't execute the host
-      # platform, we'll just disable tests and doc gen.
-      needs_exe_wrapper = false
 
-      [binaries]
+    [binaries]
-      # Meson refuses to consider any CMake binary during cross compilation if it's
+    # Meson refuses to consider any CMake binary during cross compilation if it's
-      # not explicitly specified here, in the cross file.
+    # not explicitly specified here, in the cross file.
-      # https://github.com/mesonbuild/meson/blob/0ed78cf6fa6d87c0738f67ae43525e661b50a8a2/mesonbuild/cmake/executor.py#L72
+    # https://github.com/mesonbuild/meson/blob/0ed78cf6fa6d87c0738f67ae43525e661b50a8a2/mesonbuild/cmake/executor.py#L72
-      cmake = 'cmake'
+    cmake = 'cmake'
-    '';
+  '';
 
   # The internal API docs need these for the build, but if we're not building
   # Nix itself, then these don't need to be propagated.

src/build-remote/build-remote.cc

@@ -236,9 +236,9 @@ static int main_build_remote(int argc, char * * argv)
                 }
 
 #if __APPLE__
-                futimes(bestSlotLock.get(), NULL);
+                futimes(bestSlotLock.get(), nullptr);
 #else
-                futimens(bestSlotLock.get(), NULL);
+                futimens(bestSlotLock.get(), nullptr);
 #endif
 
                 lock.reset();

src/libstore/build/local-derivation-goal.cc

@@ -1882,7 +1882,7 @@ void LocalDerivationGoal::runChild()
                 sandboxArgs.push_back("_ALLOW_LOCAL_NETWORKING");
                 sandboxArgs.push_back("1");
             }
-            if (sandbox_init_with_parameters(sandboxProfile.c_str(), 0, stringsToCharPtrs(sandboxArgs).data(), NULL)) {
+            if (sandbox_init_with_parameters(sandboxProfile.c_str(), 0, stringsToCharPtrs(sandboxArgs).data(), nullptr)) {
                 writeFull(STDERR_FILENO, "failed to configure sandbox\n");
                 _exit(1);
             }

src/libstore/globals.cc

@@ -177,14 +177,14 @@ static bool hasVirt() {
     size_t size;
 
     size = sizeof(hasVMM);
-    if (sysctlbyname("kern.hv_vmm_present", &hasVMM, &size, NULL, 0) == 0) {
+    if (sysctlbyname("kern.hv_vmm_present", &hasVMM, &size, nullptr, 0) == 0) {
         if (hasVMM)
             return false;
     }
 
     // whether the kernel and hardware supports virt
     size = sizeof(hvSupport);
-    if (sysctlbyname("kern.hv_support", &hvSupport, &size, NULL, 0) == 0) {
+    if (sysctlbyname("kern.hv_support", &hvSupport, &size, nullptr, 0) == 0) {
         return hvSupport == 1;
     } else {
         return false;

src/libstore/local-store.cc

@@ -557,7 +557,7 @@ void LocalStore::openDB(State & state, bool create)
         if (sqlite3_exec(db, "pragma main.journal_size_limit = 1099511627776;", 0, 0, 0) != SQLITE_OK)
             SQLiteError::throw_(db, "setting journal_size_limit");
         int enable = 1;
-        if (sqlite3_file_control(db, NULL, SQLITE_FCNTL_PERSIST_WAL, &enable) != SQLITE_OK)
+        if (sqlite3_file_control(db, nullptr, SQLITE_FCNTL_PERSIST_WAL, &enable) != SQLITE_OK)
             SQLiteError::throw_(db, "setting persistent WAL mode");
     }
 

src/libstore/platform/darwin.cc

@@ -235,15 +235,15 @@ void DarwinLocalDerivationGoal::execBuilder(std::string builder, Strings args, S
     if (drv->platform == "aarch64-darwin") {
         // Unset kern.curproc_arch_affinity so we can escape Rosetta
         int affinity = 0;
-        sysctlbyname("kern.curproc_arch_affinity", NULL, NULL, &affinity, sizeof(affinity));
+        sysctlbyname("kern.curproc_arch_affinity", nullptr, nullptr, &affinity, sizeof(affinity));
 
         cpu_type_t cpu = CPU_TYPE_ARM64;
-        posix_spawnattr_setbinpref_np(&attrp, 1, &cpu, NULL);
+        posix_spawnattr_setbinpref_np(&attrp, 1, &cpu, nullptr);
     } else if (drv->platform == "x86_64-darwin") {
         cpu_type_t cpu = CPU_TYPE_X86_64;
-        posix_spawnattr_setbinpref_np(&attrp, 1, &cpu, NULL);
+        posix_spawnattr_setbinpref_np(&attrp, 1, &cpu, nullptr);
     }
 
-    posix_spawn(NULL, builder.c_str(), NULL, &attrp, stringsToCharPtrs(args).data(), stringsToCharPtrs(envStrs).data());
+    posix_spawn(nullptr, builder.c_str(), nullptr, &attrp, stringsToCharPtrs(args).data(), stringsToCharPtrs(envStrs).data());
 }
 }

src/libutil/file-system.cc

@@ -21,22 +21,14 @@ Path absPath(Path path, std::optional<PathView> dir, bool resolveSymlinks)
 {
     if (path.empty() || path[0] != '/') {
         if (!dir) {
-#ifdef __GNU__
-            /* GNU (aka. GNU/Hurd) doesn't have any limitation on path
-               lengths and doesn't define `PATH_MAX'.  */
-            char *buf = getcwd(NULL, 0);
-            if (buf == NULL)
-#else
             char buf[PATH_MAX];
-            if (!getcwd(buf, sizeof(buf)))
+            if (!getcwd(buf, sizeof(buf))) {
-#endif
                 throw SysError("cannot get cwd");
+            }
             path = concatStrings(buf, "/", path);
-#ifdef __GNU__
+        } else {
-            free(buf);
-#endif
-        } else
             path = concatStrings(*dir, "/", path);
+        }
     }
     return canonPath(path, resolveSymlinks);
 }

src/libutil/tarfile.cc

@@ -54,7 +54,7 @@ TarArchive::TarArchive(Source & source, bool raw) : buffer(65536)
         archive_read_support_format_raw(archive);
         archive_read_support_format_empty(archive);
     }
-    archive_read_set_option(archive, NULL, "mac-ext", NULL);
+    archive_read_set_option(archive, nullptr, "mac-ext", nullptr);
     check(archive_read_open(archive, (void *)this, callback_open, callback_read, callback_close), "Failed to open archive (%s)");
 }
 
@@ -65,7 +65,7 @@ TarArchive::TarArchive(const Path & path)
 
     archive_read_support_filter_all(archive);
     archive_read_support_format_all(archive);
-    archive_read_set_option(archive, NULL, "mac-ext", NULL);
+    archive_read_set_option(archive, nullptr, "mac-ext", nullptr);
     check(archive_read_open_filename(archive, path.c_str(), 16384), "failed to open archive: %s");
 }
 

src/nix/diff-closures.cc

@@ -24,24 +24,17 @@ GroupedPaths getClosureInfo(ref<Store> store, const StorePath & toplevel)
 
     GroupedPaths groupedPaths;
 
-    for (auto & path : closure) {
+    for (auto const & path : closure) {
         /* Strip the output name. Unfortunately this is ambiguous (we
            can't distinguish between output names like "bin" and
            version suffixes like "unstable"). */
         static std::regex regex("(.*)-([a-z]+|lib32|lib64)");
-        std::smatch match;
+        std::cmatch match;
         std::string name{path.name()};
-        // Used to keep name alive through being potentially overwritten below
+        std::string_view const origName = path.name();
-        // (to not invalidate the references from the regex result)
-        //
-        // n.b. cannot be just path.name().{begin,end}() since that returns const
-        // char *, which does not, for some reason, convert as required on
-        // libstdc++. Seems like a libstdc++ bug or standard bug to me... we
-        // can afford the allocation in any case.
-        const std::string origName{path.name()};
         std::string outputName;
 
-        if (std::regex_match(origName, match, regex)) {
+        if (std::regex_match(origName.begin(), origName.end(), match, regex)) {
             name = match[1];
             outputName = match[2];
         }

src/resolve-system-dependencies/resolve-system-dependencies.cc

@@ -48,7 +48,7 @@ std::set<std::string> runResolver(const Path & filename)
         return {};
     }
 
-    char* obj = (char*) mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd.get(), 0);
+    char* obj = (char*) mmap(nullptr, st.st_size, PROT_READ, MAP_SHARED, fd.get(), 0);
     if (!obj)
         throw SysError("mmapping '%s'", filename);