Improve linenoise and get it working on Windows

Some progress has been made on introducing completion but there's been
difficulties using the Python C API to get local shell variables.

libc/log/die.c

@@ -19,6 +19,7 @@
 #include "libc/bits/bits.h"
 #include "libc/dce.h"
 #include "libc/log/backtrace.internal.h"
+#include "libc/log/internal.h"
 #include "libc/log/log.h"
 
 /**
@@ -29,6 +30,7 @@
 relegated wontreturn void __die(void) {
   static bool once;
   if (cmpxchg(&once, false, true)) {
+    __restore_tty();
     if (IsDebuggerPresent(false)) DebugBreak();
     ShowBacktrace(2, NULL);
   }

libc/log/internal.h

@@ -2,16 +2,19 @@
 #define COSMOPOLITAN_LIBC_LOG_INTERNAL_H_
 #include "libc/calls/struct/sigaction.h"
 #include "libc/calls/struct/siginfo.h"
+#include "libc/calls/struct/termios.h"
 #include "libc/calls/ucontext.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
 extern int kCrashSigs[8] hidden;
+extern struct termios g_oldtermios hidden;
 extern struct sigaction g_oldcrashacts[8] hidden;
 
 void __start_fatal(const char *, int) hidden;
 void __start_fatal_ndebug(void) hidden;
 void __oncrash(int, struct siginfo *, struct ucontext *) relegated;
+void __restore_tty(void);
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */

libc/log/oldtermios.c

@@ -0,0 +1,45 @@
+/*-*- 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 2021 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/termios.h"
+#include "libc/log/internal.h"
+#include "libc/str/str.h"
+
+#define SHOW_CURSOR   "\e[?25h"
+#define DISABLE_MOUSE "\e[?1000;1002;1015;1006l"
+#define ANSI_RESTORE  SHOW_CURSOR DISABLE_MOUSE
+
+struct termios g_oldtermios;
+
+static textstartup void g_oldtermios_init() {
+  if (isatty(1)) {
+    tcgetattr(1, &g_oldtermios);
+  }
+}
+
+const void *const g_oldtermios_ctor[] initarray = {
+    g_oldtermios_init,
+};
+
+void __restore_tty(void) {
+  if (isatty(1)) {
+    write(1, ANSI_RESTORE, strlen(ANSI_RESTORE));
+    tcsetattr(1, TCSAFLUSH, &g_oldtermios);
+  }
+}

libc/log/oncrash.c

@@ -20,7 +20,9 @@
 #include "libc/calls/sigbits.h"
 #include "libc/calls/struct/sigaction.h"
 #include "libc/calls/struct/siginfo.h"
+#include "libc/calls/struct/termios.h"
 #include "libc/calls/struct/utsname.h"
+#include "libc/calls/termios.h"
 #include "libc/calls/ucontext.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
@@ -41,6 +43,7 @@
 #include "libc/sysv/consts/fileno.h"
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/consts/sig.h"
+#include "libc/sysv/consts/termios.h"
 
 /**
  * @fileoverview Abnormal termination handling & GUI debugging.
@@ -262,6 +265,7 @@ relegated void __oncrash(int sig, struct siginfo *si, ucontext_t *ctx) {
                            : 0);
   }
   if (gdbpid > 0 && (sig == SIGTRAP || sig == SIGQUIT)) return;
+  __restore_tty();
   ShowCrashReport(err, STDERR_FILENO, sig, si, ctx);
   exit(128 + sig);
   unreachable;

libc/log/showcrashreports.c

@@ -20,6 +20,7 @@
 #include "libc/bits/bits.h"
 #include "libc/calls/calls.h"
 #include "libc/calls/sigbits.h"
+#include "libc/calls/termios.h"
 #include "libc/calls/typedef/sigaction_f.h"
 #include "libc/dce.h"
 #include "libc/log/check.h"

libc/log/startfatal.c

@@ -32,6 +32,7 @@
 relegated void __start_fatal(const char *file, int line) {
   bool colorful;
   char s[16 + 16 + 16 + 16 + PATH_MAX + 16 + NAME_MAX + 16], *p = s;
+  __restore_tty();
   colorful = cancolor();
   *p++ = '\r';
   if (colorful) p = stpcpy(p, "\e[J\e[30;101m");

libc/log/startfatal_ndebug.c

@@ -29,6 +29,7 @@
  */
 relegated void __start_fatal_ndebug(void) {
   char s[16 + 16 + 16 + 16 + PATH_MAX + 16], *p = s;
+  __restore_tty();
   *p++ = '\r';
   if (cancolor()) p = stpcpy(p, "\e[J");
   p = stpcpy(p, "error:");