Make improvements for Actually Portable Emacs

- Get SIGWINCH working again on the New Technology
- Correctly handle O_NOFOLLOW in open() on Windows
- Implement synthetic umask() functionality on Windows
- Do a better job managing file execute access on Windows
- Fill in `st_uid` and `st_gid` with username hash on Windows
- Munge UNICODE control pictures into control codes on Windows
- Do a better job ensuring Windows console settings are restored
- Introduce KPRINTF_LOG environment variable to log kprintf to a file

libc/log/backtrace2.c

@@ -148,11 +148,11 @@ static int PrintBacktraceUsingAddr2line(int fd, const struct StackFrame *bp) {
                        strlen(" (discriminator ") - 1)) &&
           (p3 = memchr(p2, '\n', got - (p2 - p1)))) {
         if (p3 > p2 && p3[-1] == '\r') --p3;
-        _klog(p1, p2 - p1);
+        klog(p1, p2 - p1);
         got -= p3 - p1;
         p1 += p3 - p1;
       } else {
-        _klog(p1, got);
+        klog(p1, got);
         break;
       }
     }

libc/log/checkfail_ndebug.c

@@ -49,7 +49,7 @@ static relegated wontreturn void __check_fail_ndebug(uint64_t want,       //
   }
   kprintf("\n");
   if (_weaken(__die)) _weaken(__die)();
-  _Exitr(68);
+  _Exit(68);
 }
 
 void __check_fail_eq(uint64_t want, uint64_t got, const char *file, int line,

libc/log/die.c

@@ -55,10 +55,10 @@ relegated wontreturn void __die(void) {
       DebugBreak();
     }
     ShowBacktrace(2, __builtin_frame_address(0));
-    _Exitr(77);
+    _Exit(77);
   } else if (owner == me) {
     kprintf("die failed while dying\n");
-    _Exitr(79);
+    _Exit(79);
   } else {
     _Exit1(79);
   }

libc/log/leaks.c

@@ -115,6 +115,6 @@ dontasan void CheckForMemoryLeaks(void) {
     /* __print_maps(); */
     /* PrintSystemMappings(2); */
     /* PrintGarbage(); */
-    _Exitr(78);
+    _Exit(78);
   }
 }

libc/log/log.h

@@ -41,7 +41,6 @@ void _meminfo(int);                    /* shows malloc statistics &c. */
 void _memsummary(int);                 /* light version of same thing */
 bool IsTerminalInarticulate(void) nosideeffect;
 const char *commandvenv(const char *, const char *);
-int LogKprintfToFile(const char *);
 const char *GetAddr2linePath(void);
 const char *GetGdbPath(void);
 bool32 IsDebuggerPresent(bool);

libc/log/log_exit.c

@@ -20,5 +20,5 @@
 #include "libc/runtime/runtime.h"
 
 wontreturn void _log_exit(int exitcode) {
-  _Exitr(exitcode);
+  _Exit(exitcode);
 }

libc/log/logkprintftofile.c

@@ -1,57 +0,0 @@
-/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
-│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
-╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
-│                                                                              │
-│ Permission to use, copy, modify, and/or distribute this software for         │
-│ any purpose with or without fee is hereby granted, provided that the         │
-│ above copyright notice and this permission notice appear in all copies.      │
-│                                                                              │
-│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
-│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
-│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
-│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
-│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
-│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
-│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
-│ PERFORMANCE OF THIS SOFTWARE.                                                │
-╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/calls/calls.h"
-#include "libc/calls/internal.h"
-#include "libc/dce.h"
-#include "libc/log/log.h"
-#include "libc/sysv/consts/f.h"
-#include "libc/sysv/consts/o.h"
-
-static int __klog_fd;
-extern long __klog_handle;
-
-/**
- * Redirects kprintf(), `--strace`, etc. output to file.
- *
- * @param path is filename to append to; if null is specified then
- *     this file logging facility will be disabled; when the empty
- *     string is specified, then the default path shall be used
- * @return 0 on success, or -1 w/ errno
- */
-int LogKprintfToFile(const char *path) {
-  int fd, dd;
-  if (!path) {
-    if (__klog_fd) {
-      __klog_handle = 0;
-      close(__klog_fd);
-      __klog_fd = 0;
-    }
-    return 0;
-  }
-  if (!*path) path = "/tmp/kprintf.log";
-  fd = open(path, O_WRONLY | O_APPEND | O_CREAT, 0644);
-  if (fd == -1) return -1;
-  dd = fcntl(fd, F_DUPFD_CLOEXEC, 100);
-  close(fd);
-  if (dd == -1) return -1;
-  if (__klog_fd) close(__klog_fd);
-  __klog_fd = dd;
-  __klog_handle = IsWindows() ? g_fds.p[dd].handle : dd;
-  return 0;
-}

libc/log/oncrash_amd64.c

@@ -239,11 +239,11 @@ relegated void ShowCrashReport(int err, int sig, struct siginfo *si,
     p = ShowGeneralRegisters(p, ctx);
     p = ShowSseRegisters(p, ctx);
     *p++ = '\n';
-    _klog(buf, p - buf);
+    klog(buf, p - buf);
     ShowFunctionCalls(ctx);
   } else {
     *p++ = '\n';
-    _klog(buf, p - buf);
+    klog(buf, p - buf);
   }
   kprintf("\n");
   if (!IsWindows()) __print_maps();
@@ -275,7 +275,7 @@ static wontreturn relegated dontinstrument void __minicrash(int sig,
           kind, sig, __argv[0], ctx ? ctx->uc_mcontext.rip : 0,
           ctx ? ctx->uc_mcontext.rsp : 0, ctx ? ctx->uc_mcontext.rbp : 0, __pid,
           __tls_enabled ? __get_tls()->tib_tid : sys_gettid());
-  _Exitr(119);
+  _Exit(119);
 }
 
 /**
@@ -334,7 +334,7 @@ relegated void __oncrash_amd64(int sig, struct siginfo *si, void *arg) {
       if (!(gdbpid > 0 && (sig == SIGTRAP || sig == SIGQUIT))) {
         __restore_tty();
         ShowCrashReport(err, sig, si, ctx);
-        _Exitr(128 + sig);
+        _Exit(128 + sig);
       }
       atomic_store_explicit(&once, 0, memory_order_relaxed);
     } else {