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https://github.com/jart/cosmopolitan.git
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f4f4caab0e
I wanted a tiny scriptable meltdown proof way to run userspace programs and visualize how program execution impacts memory. It helps to explain how things like Actually Portable Executable works. It can show you how the GCC generated code is going about manipulating matrices and more. I didn't feel fully comfortable with Qemu and Bochs because I'm not smart enough to understand them. I wanted something like gVisor but with much stronger levels of assurances. I wanted a single binary that'll run, on all major operating systems with an embedded GPL barrier ZIP filesystem that is tiny enough to transpile to JavaScript and run in browsers too. https://justine.storage.googleapis.com/emulator625.mp4
121 lines
5.3 KiB
C
121 lines
5.3 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/bits/weaken.h"
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#include "libc/calls/internal.h"
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#include "libc/dce.h"
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#include "libc/log/log.h"
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#include "libc/nt/console.h"
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#include "libc/nt/enum/consolemodeflags.h"
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#include "libc/nt/enum/filetype.h"
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#include "libc/nt/enum/version.h"
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#include "libc/nt/files.h"
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#include "libc/nt/pedef.h"
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#include "libc/nt/runtime.h"
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#include "libc/nt/struct/teb.h"
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#include "libc/runtime/runtime.h"
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#include "libc/str/str.h"
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#include "libc/sysv/consts/fileno.h"
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static struct CanColor {
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bool once;
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bool result;
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struct OldNtConsole {
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unsigned codepage;
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unsigned mode;
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int64_t handle;
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} oldin, oldout;
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} g_cancolor;
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static textwindows void restorecmdexe(void) {
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if (g_cancolor.oldin.handle) {
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SetConsoleCP(g_cancolor.oldin.codepage);
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SetConsoleMode(g_cancolor.oldin.handle, g_cancolor.oldin.mode);
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}
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if (g_cancolor.oldout.handle) {
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SetConsoleOutputCP(g_cancolor.oldout.codepage);
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SetConsoleMode(g_cancolor.oldout.handle, g_cancolor.oldout.mode);
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}
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}
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/**
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* Returns true if ANSI terminal colors are appropriate.
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*
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* We take an optimistic approach here. We use colors, unless we see the
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* environment variable TERM=dumb, which is set by software like Emacs.
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* It's a common antipattern to check isatty(STDERR_FILENO), since that
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* usually makes colors harder to get than they are to remove:
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*
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* sed 's/\x1b\[[;[:digit:]]*m//g' <color.txt >uncolor.txt
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*
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* Ideally, all software should be updated to understand color, since
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* it's been formally standardized nearly as long as ASCII. Even old
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* MS-DOS supports it (but Windows didn't until Windows 10) yet even
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* tools like less may need wrapper scripts, e.g.:
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*
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* #!/bin/sh
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* LESSCHARSET=UTF-8 exec /usr/bin/less -RS "$@"
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*
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* It's that easy fam.
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*/
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bool cancolor(void) {
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int64_t handle;
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const char *term;
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if (g_cancolor.once) return g_cancolor.result;
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g_cancolor.once = true;
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if (IsWindows()) {
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if ((int)weakaddr("v_ntsubsystem") == kNtImageSubsystemWindowsCui &&
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NtGetVersion() >= kNtVersionWindows10) {
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atexit(restorecmdexe);
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if (GetFileType((handle = g_fds.p[STDIN_FILENO].handle)) ==
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kNtFileTypeChar) {
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g_cancolor.result = true;
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g_cancolor.oldin.handle = handle;
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g_cancolor.oldin.codepage = GetConsoleCP();
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SetConsoleCP(kNtCpUtf8);
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GetConsoleMode(handle, &g_cancolor.oldin.mode);
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SetConsoleMode(handle, g_cancolor.oldin.mode | kNtEnableProcessedInput |
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kNtEnableVirtualTerminalInput);
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}
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if (GetFileType((handle = g_fds.p[STDOUT_FILENO].handle)) ==
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kNtFileTypeChar ||
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GetFileType((handle = g_fds.p[STDERR_FILENO].handle)) ==
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kNtFileTypeChar) {
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g_cancolor.result = true;
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g_cancolor.oldout.handle = handle;
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g_cancolor.oldout.codepage = GetConsoleOutputCP();
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SetConsoleOutputCP(kNtCpUtf8);
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GetConsoleMode(handle, &g_cancolor.oldout.mode);
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SetConsoleMode(handle, g_cancolor.oldout.mode |
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kNtEnableProcessedOutput |
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kNtEnableVirtualTerminalProcessing);
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}
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}
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}
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if (!g_cancolor.result) {
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if ((term = getenv("TERM"))) {
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/* anything but emacs basically */
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g_cancolor.result = strcmp(term, "dumb") != 0;
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} else {
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/* TODO(jart): Why does Mac bash login shell exec nuke TERM? */
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g_cancolor.result = IsXnu();
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}
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}
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return g_cancolor.result;
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}
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