Make exciting improvements

- Add Lua backtraces to redbean!
- Wipe serving keys after redbean forks
- Audit redbean to remove free via exit
- Log SSL client ciphersuite preferences
- Increase ASAN malloc() backtrace depth
- Make GetSslRoots() behave as a singleton
- Move leaks.c from LIBC_TESTLIB to LIBC_LOG
- Add undocumented %n to printf() for newlines
- Fix redbean memory leak reindexing inode change
- Fix redbean memory leak with Fetch() DNS object
- Restore original environ after __cxa_finalize()
- Make backtrace always work after __cxa_finalize()
- Introduce COUNTEXPR() diagnostic / benchmark tool
- Fix a few more instances of errno being clobbered
- Consolidate the ANSI color disabling internal APIs

libc/intrin/nocolor.c

@@ -0,0 +1,61 @@
+/*-*- 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 2020 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/dce.h"
+#include "libc/log/internal.h"
+#include "libc/nt/version.h"
+#include "libc/runtime/runtime.h"
+
+#define IsDumb(s) \
+  (s[0] == 'd' && s[1] == 'u' && s[2] == 'm' && s[3] == 'b' && !s[4])
+
+/**
+ * Indicates if ANSI terminal colors are inappropriate.
+ *
+ * Normally this variable should be false. We only set it to true if
+ * we're running on an old version of Windows or the environment
+ * variable `TERM` is set to `dumb`.
+ *
+ * We think colors should be the norm, since most software is usually
+ * too conservative about removing them. Rather than using `isatty`
+ * consider using sed for instances where color must be removed:
+ *
+ *      sed 's/\x1b\[[;[:digit:]]*m//g' <color.txt >uncolor.txt
+ *
+ * For some reason, important software is configured by default in many
+ * operating systems, to not only disable colors, but utf-8 too! Here's
+ * an example of how a wrapper script can fix that for `less`.
+ *
+ *      #!/bin/sh
+ *      LESSCHARSET=UTF-8 exec /usr/bin/less -RS "$@"
+ *
+ * Thank you for using colors!
+ */
+bool __nocolor;
+
+optimizesize textstartup noasan void __nocolor_init(int argc, char **argv,
+                                                    char **envp,
+                                                    intptr_t *auxv) {
+  char *s;
+  __nocolor = (IsWindows() && !IsAtLeastWindows10()) ||
+              ((s = getenv("TERM")) && IsDumb(s));
+}
+
+const void *const __nocolor_ctor[] initarray = {
+    __nocolor_init,
+};