Make improvements

- Fix build flakes
- Polyfill SIGWINCH on Windows
- Fix an execve issue on Windows
- Make strerror show more information
- Improve cmd.exe setup/teardown on Windows
- Support bracketed paste mode in Blinkenlights
- Show keyboard shortcuts in Blinkenlights status bar
- Fixed copy_file_range() and copyfile() w/ zip filesystem
- Size optimize GetDosArgv() to keep life.com 12kb in size
- Improve Blinkenlights ability to load weird ELF executables
- Fix program_executable_name and add GetInterpreterExecutableName
- Make Python in tiny mode fail better if docstrings are requested
- Update Python test exclusions in tiny* modes such as tinylinux
- Add bulletproof unbreakable kprintf() troubleshooting function
- Remove "oldskool" keyword from ape.S for virus scanners
- Fix issue that caused backtraces to not print sometimes
- Improve Blinkenlights serial uart character i/o
- Make clock_gettime() not clobber errno on xnu
- Improve sha256 cpuid check for old computers
- Integrate some bestline linenoise fixes
- Show runit process names better in htop
- Remove SIGPIPE from ShowCrashReports()
- Make realpath() not clobber errno
- Avoid attaching GDB on non-Linux
- Improve img.com example

libc/calls/program_executable_name.c

@@ -0,0 +1,133 @@
+/*-*- 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/assert.h"
+#include "libc/bits/bits.h"
+#include "libc/calls/calls.h"
+#include "libc/calls/internal.h"
+#include "libc/calls/sysdebug.internal.h"
+#include "libc/dce.h"
+#include "libc/errno.h"
+#include "libc/log/libfatal.internal.h"
+#include "libc/macros.internal.h"
+#include "libc/mem/alloca.h"
+#include "libc/nt/runtime.h"
+#include "libc/runtime/runtime.h"
+#include "libc/str/str.h"
+#include "libc/str/tpenc.h"
+#include "libc/str/utf16.h"
+#include "libc/sysv/consts/at.h"
+#include "libc/sysv/consts/auxv.h"
+#include "libc/sysv/consts/ok.h"
+#include "libc/sysv/consts/prot.h"
+
+#define SIZE                       1024
+#define CTL_KERN                   1
+#define KERN_PROC                  14
+#define KERN_PROC_PATHNAME_FREEBSD 12
+#define KERN_PROC_PATHNAME_NETBSD  5
+
+/**
+ * Absolute path of executable.
+ *
+ * This variable is initialized automatically at startup. The path is
+ * basically `argv[0]` except some extra vetting is done to provide
+ * stronger assurance that the path can be counted upon to exist.
+ *
+ * For example, if your program is executed as a relative path and then
+ * your program calls `chdir()`, then `argv[0]` will be incorrect; but
+ * `program_executable_name` will work, because it prefixed `getcwd()`
+ * early in the initialization phase.
+ *
+ * @see GetInterpreterExecutableName()
+ * @see program_invocation_short_name
+ * @see program_invocation_name
+ */
+char program_executable_name[SIZE];
+
+static textwindows bool GetNtExePath(char executable[SIZE]) {
+  uint64_t w;
+  wint_t x, y;
+  uint32_t i, j;
+  char16_t path16[PATH_MAX + 1];
+  if (!GetModuleFileName(0, path16, ARRAYLEN(path16))) return 0;
+  for (i = j = 0; (x = path16[i++] & 0xffff);) {
+    if (!IsUcs2(x)) {
+      y = path16[i++] & 0xffff;
+      x = MergeUtf16(x, y);
+    }
+    if (x == '\\') x = '/';
+    w = tpenc(x);
+    do {
+      executable[j] = w;
+      if (++j == SIZE) {
+        return false;
+      }
+    } while ((w >>= 8));
+  }
+  executable[j] = 0;
+  return true;
+}
+
+static textstartup void GetProgramExecutableName(char executable[SIZE],
+                                                 char *argv0, intptr_t *auxv) {
+  size_t m;
+  ssize_t n;
+  int cmd[4];
+  char *p, *t;
+  if (IsWindows() && GetNtExePath(executable)) return;
+  for (p = 0; *auxv; auxv += 2) {
+    if (*auxv == AT_EXECFN) {
+      p = (char *)auxv[1];
+      break;
+    }
+  }
+  n = 0;
+  if (!p) p = argv0;
+  if (p) {
+    if (!_isabspath(p)) {
+      if (getcwd(executable, SIZE - 1)) {
+        n = strlen(executable);
+        executable[n++] = '/';
+      }
+    }
+    for (; *p; ++p) {
+      if (n + 1 < SIZE) {
+        executable[n++] = *p;
+      }
+    }
+  }
+  executable[n] = 0;
+}
+
+textstartup void program_executable_name_init(int argc, char **argv,
+                                              char **envp, intptr_t *auxv) {
+  int e;
+  static bool once;
+  char executable[SIZE];
+  if (!cmpxchg(&once, 0, 1)) return;
+  e = errno;
+  GetProgramExecutableName(executable, argv[0], auxv);
+  errno = e;
+  __stpcpy(program_executable_name, executable);
+  SYSDEBUG("program_executable_name → %#s", program_executable_name);
+}
+
+const void *const program_executable_name_init_ctor[] initarray = {
+    program_executable_name_init,
+};