Fix bugs and make improvements

- Get clone() working on FreeBSD
- Increase some Python build quotas
- Add more atomic builtins to chibicc
- Fix ASAN poisoning of alloca() memory
- Make MODE= mandatory link path tinier
- Improve the examples folder a little bit
- Start working on some more resource limits
- Make the linenoise auto-complete UI as good as GNU readline
- Update compile.com, avoiding AVX codegen on non-AVX systems
- Make sure empty path to syscalls like opendir raises ENOENT
- Correctly polyfill ENOENT vs. ENOTDIR on the New Technology
- Port bestline's paredit features to //third_party/linenoise
- Remove workarounds for RHEL 5.0 bugs that were fixed in 5.1

test/libc/calls/access_test.c

@@ -36,6 +36,7 @@ TEST(access, efault) {
 }
 
 TEST(access, enoent) {
+  ASSERT_SYS(ENOENT, -1, access("", F_OK));
   ASSERT_SYS(ENOENT, -1, access("doesnotexist", F_OK));
   ASSERT_SYS(ENOENT, -1, access("o/doesnotexist", F_OK));
 }

test/libc/calls/chdir_test.c

@@ -30,6 +30,7 @@ TEST(chdir, efault) {
 }
 
 TEST(chdir, enoent) {
+  ASSERT_SYS(ENOENT, -1, chdir(""));
   ASSERT_SYS(ENOENT, -1, chdir("doesnotexist"));
   ASSERT_SYS(ENOENT, -1, chdir("o/doesnotexist"));
 }

test/libc/calls/fork_test.c

@@ -22,6 +22,7 @@
 #include "libc/sysv/consts/map.h"
 #include "libc/sysv/consts/msync.h"
 #include "libc/sysv/consts/prot.h"
+#include "libc/testlib/ezbench.h"
 #include "libc/testlib/testlib.h"
 
 TEST(fork, testPipes) {
@@ -77,3 +78,16 @@ TEST(fork, testSharedMemory) {
   EXPECT_NE(-1, munmap(sharedvar, FRAMESIZE));
   EXPECT_NE(-1, munmap(privatevar, FRAMESIZE));
 }
+
+void ForkInSerial(void) {
+  int pid, ws;
+  ASSERT_NE(-1, (pid = fork()));
+  if (!pid) _Exit(0);
+  ASSERT_NE(-1, waitpid(pid, &ws, 0));
+  ASSERT_TRUE(WIFEXITED(ws));
+  ASSERT_EQ(0, WEXITSTATUS(ws));
+}
+
+BENCH(fork, bench) {
+  EZBENCH2("fork", donothing, ForkInSerial());
+}

test/libc/calls/open_test.c

@@ -31,6 +31,7 @@ TEST(open, efault) {
 }
 
 TEST(open, enoent) {
+  ASSERT_SYS(ENOENT, -1, open("", O_RDONLY));
   ASSERT_SYS(ENOENT, -1, open("doesnotexist", O_RDONLY));
   ASSERT_SYS(ENOENT, -1, open("o/doesnotexist", O_RDONLY));
 }

test/libc/calls/pipe_test.c

@@ -0,0 +1,75 @@
+/*-*- 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 2022 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/dce.h"
+#include "libc/errno.h"
+#include "libc/sysv/consts/rlimit.h"
+#include "libc/testlib/testlib.h"
+
+int ws, pid, f[2];
+char buf[6] = {0};
+struct rlimit rlim = {0, 10};
+
+TEST(pipe, efault) {
+  EXPECT_SYS(EFAULT, -1, pipe(0));
+}
+
+TEST(pipe, einval) {
+  EXPECT_SYS(EINVAL, -1, pipe2(f, -1));
+}
+
+TEST(pipe, ebadf) {
+  if (IsFreebsd()) return;  // somehow succeeds
+  if (IsOpenbsd()) return;  // somehow succeeds
+  EXPECT_SYS(0, 0, pipe(f));
+  EXPECT_SYS(EBADF, -1, write(f[0], "h", 1));
+  EXPECT_SYS(EBADF, -1, read(f[1], buf, 1));
+  EXPECT_SYS(0, 0, close(f[0]));
+  EXPECT_SYS(0, 0, close(f[1]));
+}
+
+TEST(pipe, emfile) {
+  if (IsWindows()) return;  // TODO
+  ASSERT_NE(-1, (pid = fork()));
+  if (!pid) {
+    ASSERT_EQ(0, setrlimit(RLIMIT_NOFILE, &rlim));
+    ASSERT_SYS(EMFILE, -1, pipe(f));
+    _exit(0);
+  }
+  EXPECT_NE(-1, waitpid(pid, &ws, 0));
+  EXPECT_TRUE(WIFEXITED(ws));
+  EXPECT_EQ(0, WEXITSTATUS(ws));
+}
+
+TEST(pipe, usesLowestFileNumbers) {
+  EXPECT_SYS(0, 0, pipe(f));
+  EXPECT_SYS(0, 3, f[0]);
+  EXPECT_SYS(0, 4, f[1]);
+  EXPECT_SYS(0, 0, close(f[0]));
+  EXPECT_SYS(0, 0, close(f[1]));
+}
+
+TEST(pipe, doesBuffering) {
+  EXPECT_SYS(0, 0, pipe(f));
+  EXPECT_SYS(0, 5, write(f[1], "hello", 5));
+  EXPECT_SYS(0, 5, read(f[0], buf, 5));
+  EXPECT_STREQ("hello", buf);
+  EXPECT_SYS(0, 0, close(f[0]));
+  EXPECT_SYS(0, 0, close(f[1]));
+}

test/libc/calls/readansi_test.c

@@ -52,6 +52,7 @@ TEST(readansi, test) {
   EXPECT_STREQ("\xc2\x9bM", b);
   EXPECT_EQ(0, readansi(fds[0], b, sizeof(b)));
   EXPECT_STREQ("", b);
+  close(fds[0]);
   ASSERT_NE(-1, wait(&ws));
   ASSERT_TRUE(WIFEXITED(ws));
   ASSERT_EQ(0, WEXITSTATUS(ws));
@@ -73,6 +74,7 @@ TEST(readansi, testOperatingSystemCommand) {
   EXPECT_STREQ(s, b);
   EXPECT_EQ(0, readansi(fds[0], b, sizeof(b)));
   EXPECT_STREQ("", b);
+  close(fds[0]);
   ASSERT_NE(-1, wait(&ws));
   ASSERT_TRUE(WIFEXITED(ws));
   ASSERT_EQ(0, WEXITSTATUS(ws));

test/libc/calls/readlinkat_test.c

@@ -31,6 +31,18 @@
 
 char testlib_enable_tmp_setup_teardown;
 
+TEST(readlink, enoent) {
+  char buf[32];
+  ASSERT_SYS(ENOENT, -1, readlink("doesnotexist", buf, 32));
+  ASSERT_SYS(ENOENT, -1, readlink("o/doesnotexist", buf, 32));
+}
+
+TEST(readlink, enotdir) {
+  char buf[32];
+  ASSERT_SYS(0, 0, touch("o", 0644));
+  ASSERT_SYS(ENOTDIR, -1, readlink("o/doesnotexist", buf, 32));
+}
+
 TEST(readlinkat, test) {
   char buf[128], *p, *q;
   memset(buf, -1, sizeof(buf));

test/libc/calls/renameat_test.c

@@ -24,6 +24,20 @@
 
 char testlib_enable_tmp_setup_teardown;
 
+TEST(rename, enoent) {
+  EXPECT_SYS(ENOENT, -1, rename("foo", ""));
+  EXPECT_SYS(ENOENT, -1, rename("", "foo"));
+  EXPECT_SYS(ENOENT, -1, rename("foo", "o/bar"));
+  EXPECT_SYS(ENOENT, -1, rename("o/bar", "foo"));
+}
+
+TEST(renameat, enotdir) {
+  EXPECT_SYS(0, 0, close(creat("yo", 0644)));
+  EXPECT_SYS(ENOTDIR, -1, rename("yo/there", "hrcue"));
+  // this test makes platforms crazy
+  // EXPECT_SYS(ENOTDIR, -1, rename("zoo", "yo/there"));
+}
+
 TEST(renameat, testNull_returnsEfault) {
   ASSERT_SYS(0, 0, close(creat("hello", 0644)));
   EXPECT_SYS(EFAULT, -1, renameat(AT_FDCWD, 0, AT_FDCWD, 0));

test/libc/calls/stat_test.c

@@ -43,6 +43,7 @@ TEST(stat_010, testEmptyFile_sizeIsZero) {
 
 TEST(stat, enoent) {
   ASSERT_SYS(ENOENT, -1, stat("hi", 0));
+  ASSERT_SYS(ENOENT, -1, stat("o/doesnotexist", 0));
 }
 
 TEST(stat, enotdir) {

test/libc/calls/symlinkat_test.c

@@ -29,6 +29,16 @@ char testlib_enable_tmp_setup_teardown;
 char p[2][PATH_MAX];
 struct stat st;
 
+TEST(symlink, enoent) {
+  ASSERT_SYS(ENOENT, -1, symlink("o/foo", ""));
+  ASSERT_SYS(ENOENT, -1, symlink("o/foo", "o/bar"));
+}
+
+TEST(symlinkat, enotdir) {
+  ASSERT_SYS(0, 0, close(creat("yo", 0644)));
+  ASSERT_SYS(ENOTDIR, -1, symlink("hrcue", "yo/there"));
+}
+
 TEST(symlinkat, test) {
   sprintf(p[0], "%s.%d", program_invocation_short_name, rand());
   sprintf(p[1], "%s.%d", program_invocation_short_name, rand());

test/libc/calls/unlinkat_test.c

@@ -17,11 +17,29 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
+#include "libc/dce.h"
 #include "libc/sysv/consts/at.h"
 #include "libc/testlib/testlib.h"
 
 char testlib_enable_tmp_setup_teardown;
 
+TEST(unlink, efault) {
+  ASSERT_SYS(EFAULT, -1, unlink(0));
+  if (IsWindows() && !IsAsan()) return;  // not possible
+  ASSERT_SYS(EFAULT, -1, unlink((void *)77));
+}
+
+TEST(unlink, enoent) {
+  ASSERT_SYS(ENOENT, -1, unlink(""));
+  ASSERT_SYS(ENOENT, -1, unlink("doesnotexist"));
+  ASSERT_SYS(ENOENT, -1, unlink("o/doesnotexist"));
+}
+
+TEST(unlink, enotdir) {
+  ASSERT_SYS(0, 0, touch("o", 0644));
+  ASSERT_SYS(ENOTDIR, -1, unlink("o/doesnotexist"));
+}
+
 TEST(unlinkat, test) {
   int i, fd;
   EXPECT_EQ(0, touch("mytmp", 0644));