Make a few commands that were Unix-only no longer

Also clean up some more linux-specific (`setPersonality`) code in
alignment with recent best practices.

src/libstore/linux/personality.cc

@@ -1,18 +1,15 @@
 #include "personality.hh"
 #include "globals.hh"
 
-#if __linux__
 #include <sys/utsname.h>
 #include <sys/personality.h>
-#endif
 
 #include <cstring>
 
-namespace nix {
+namespace nix::linux {
 
 void setPersonality(std::string_view system)
 {
-#if __linux__
         /* Change the personality to 32-bit if we're doing an
            i686-linux build on an x86_64-linux machine. */
         struct utsname utsbuf;
@@ -39,7 +36,6 @@ void setPersonality(std::string_view system)
            determinism. */
         int cur = personality(0xffffffff);
         if (cur != -1) personality(cur | ADDR_NO_RANDOMIZE);
-#endif
 }
 
 }

src/libstore/linux/personality.hh

@@ -3,7 +3,7 @@
 
 #include <string>
 
-namespace nix {
+namespace nix::linux {
 
 void setPersonality(std::string_view system);
 

src/libstore/local.mk

@@ -8,6 +8,9 @@ libstore_SOURCES := $(wildcard $(d)/*.cc $(d)/builtins/*.cc)
 ifdef HOST_UNIX
   libstore_SOURCES += $(wildcard $(d)/unix/*.cc $(d)/unix/builtins/*.cc $(d)/unix/build/*.cc)
 endif
+ifdef HOST_LINUX
+  libstore_SOURCES += $(wildcard $(d)/linux/*.cc)
+endif
 ifdef HOST_WINDOWS
   libstore_SOURCES += $(wildcard $(d)/windows/*.cc)
 endif
@@ -39,6 +42,9 @@ INCLUDE_libstore := -I $(d) -I $(d)/build
 ifdef HOST_UNIX
   INCLUDE_libstore += -I $(d)/unix
 endif
+ifdef HOST_LINUX
+  INCLUDE_libstore += -I $(d)/linux
+endif
 ifdef HOST_WINDOWS
   INCLUDE_libstore += -I $(d)/windows
 endif

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

@@ -14,7 +14,6 @@
 #include "topo-sort.hh"
 #include "callback.hh"
 #include "json-utils.hh"
-#include "personality.hh"
 #include "current-process.hh"
 #include "child.hh"
 #include "unix-domain-socket.hh"
@@ -52,6 +51,7 @@
 # endif
 # define pivot_root(new_root, put_old) (syscall(SYS_pivot_root, new_root, put_old))
 # include "cgroup.hh"
+# include "personality.hh"
 #endif
 
 #if __APPLE__
@@ -1957,7 +1957,9 @@ void LocalDerivationGoal::runChild()
         /* Close all other file descriptors. */
         closeMostFDs({STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO});
 
-        setPersonality(drv->platform);
+#if __linux__
+        linux::setPersonality(drv->platform);
+#endif
 
         /* Disable core dumps by default. */
         struct rlimit limit = { 0, RLIM_INFINITY };

src/nix/run.cc

@@ -5,15 +5,15 @@
 #include "shared.hh"
 #include "store-api.hh"
 #include "derivations.hh"
-#include "local-store.hh"
+#include "local-fs-store.hh"
 #include "finally.hh"
 #include "source-accessor.hh"
 #include "progress-bar.hh"
 #include "eval.hh"
-#include "build/personality.hh"
 
 #if __linux__
-#include <sys/mount.h>
+# include <sys/mount.h>
+# include "personality.hh"
 #endif
 
 #include <queue>
@@ -56,8 +56,10 @@ void runProgramInStore(ref<Store> store,
         throw SysError("could not execute chroot helper");
     }
 
+#if __linux__
     if (system)
-        setPersonality(*system);
+        linux::setPersonality(*system);
+#endif
 
     if (useSearchPath == UseSearchPath::Use)
         execvp(program.c_str(), stringsToCharPtrs(args).data());
@@ -277,8 +279,10 @@ void chrootHelper(int argc, char * * argv)
     writeFile("/proc/self/uid_map", fmt("%d %d %d", uid, uid, 1));
     writeFile("/proc/self/gid_map", fmt("%d %d %d", gid, gid, 1));
 
+#if __linux__
     if (system != "")
-        setPersonality(system);
+        linux::setPersonality(system);
+#endif
 
     execvp(cmd.c_str(), stringsToCharPtrs(args).data());