Undiamond Python headers

This change gets the Python codebase into a state where it conforms to
the conventions of this codebase. It's now possible to include headers
from Python, without worrying about ordering. Python has traditionally
solved that problem by "diamonding" everything in Python.h, but that's
problematic since it means any change to any Python header invalidates
all the build artifacts. Lastly it makes tooling not work. Since it is
hard to explain to Emacs when I press C-c C-h to add an import line it
shouldn't add the header that actually defines the symbol, and instead
do follow the nonstandard Python convention.

Progress has been made on letting Python load source code from the zip
executable structure via the standard C library APIs. System calss now
recognizes zip!FILENAME alternative URIs as equivalent to zip:FILENAME
since Python uses colon as its delimiter.

Some progress has been made on embedding the notice license terms into
the Python object code. This is easier said than done since Python has
an extremely complicated ownership story.

- Some termios APIs have been added
- Implement rewinddir() dirstream API
- GetCpuCount() API added to Cosmopolitan Libc
- More bugs in Cosmopolitan Libc have been fixed
- zipobj.com now has flags for mangling the path
- Fixed bug a priori with sendfile() on certain BSDs
- Polyfill F_DUPFD and F_DUPFD_CLOEXEC across platforms
- FIOCLEX / FIONCLEX now polyfilled for fast O_CLOEXEC changes
- APE now supports a hybrid solution to no-self-modify for builds
- Many BSD-only magnums added, e.g. O_SEARCH, O_SHLOCK, SF_NODISKIO

libc/runtime/getcpucount.c

@@ -0,0 +1,84 @@
+/*-*- 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/popcnt.h"
+#include "libc/calls/calls.h"
+#include "libc/calls/weirdtypes.h"
+#include "libc/dce.h"
+#include "libc/macros.internal.h"
+#include "libc/nt/dll.h"
+#include "libc/nt/struct/systeminfo.h"
+#include "libc/nt/systeminfo.h"
+#include "libc/runtime/runtime.h"
+
+#define CTL_HW                6
+#define HW_NCPU               3
+#define HW_NCPUONLINE_OPENBSD 25
+#define HW_NCPUONLINE_NETBSD  16
+#define ALL_PROCESSOR_GROUPS  0xffff
+
+/**
+ * Returns number of CPUs in system.
+ *
+ * On Intel systems with HyperThreading this will return the number of
+ * cores multiplied by two.
+ *
+ * @return cpu count or 0 if it couldn't be determined
+ */
+unsigned GetCpuCount(void) {
+  size_t len;
+  int i, c, n, cmd[2];
+  uint64_t cpuset[16];
+  uint32_t (*f)(uint16_t);
+  struct NtSystemInfo sysinfo;
+  if (IsWindows()) {
+    if ((f = GetProcAddress(GetModuleHandle("KERNEL32"),
+                            "GetMaximumProcessorCount"))) {
+      return f(ALL_PROCESSOR_GROUPS);
+    } else {
+      GetSystemInfo(&sysinfo);
+      return sysinfo.dwNumberOfProcessors;
+    }
+  } else if (IsBsd()) {
+    len = sizeof(c);
+    cmd[0] = CTL_HW;
+    if (IsOpenbsd()) {
+      cmd[1] = HW_NCPUONLINE_OPENBSD;
+    } else if (IsNetbsd()) {
+      cmd[1] = HW_NCPUONLINE_NETBSD;
+    } else {
+      cmd[1] = HW_NCPU;
+    }
+    if (!sysctl(cmd, 2, &c, &len, 0, 0)) {
+      return c;
+    } else {
+      return 0;
+    }
+  } else {
+    if ((n = sched_getaffinity(0, sizeof(cpuset), cpuset)) > 0) {
+      assert(!(n & 7));
+      for (n >>= 3, c = i = 0; i < ARRAYLEN(cpuset); ++i) {
+        c += popcnt(cpuset[i]);
+      }
+      return c;
+    } else {
+      return 0;
+    }
+  }
+}

libc/runtime/runtime.mk

@@ -33,6 +33,7 @@ LIBC_RUNTIME_A_CHECKS =					\
 	$(LIBC_RUNTIME_A_HDRS:%=o/$(MODE)/%.ok)
 
 LIBC_RUNTIME_A_DIRECTDEPS =				\
+	LIBC_BITS					\
 	LIBC_CALLS					\
 	LIBC_ELF					\
 	LIBC_FMT					\

libc/runtime/sysconf.c

@@ -27,13 +27,15 @@
  * - `_SC_CLK_TCK` returns number of clock ticks per second
  * - `_SC_ARG_MAX` currently always returns 32768 due to Windows
  * - `_SC_PAGESIZE` currently always returns 65536 due to Windows
+ * - `_SC_NPROCESSORS_ONLN` returns number of CPUs in the system
  *
- * You are encouraged to undiamond calls to this API as follows:
+ * Some suggestions:
  *
- * - Use `CLK_TCK` instead of `getconf(_SC_CLK_TCK)`
+ * - `CLK_TCK` should be favored over `getconf(_SC_CLK_TCK)`
  * - Use `PAGESIZE` or `FRAMESIZE` instead of `getconf(_SC_PAGESIZE)`
  */
 long sysconf(int name) {
+  int n;
   switch (name) {
     case _SC_ARG_MAX:
       return ARG_MAX;
@@ -41,6 +43,9 @@ long sysconf(int name) {
       return CLK_TCK;
     case _SC_PAGESIZE:
       return FRAMESIZE;
+    case _SC_NPROCESSORS_ONLN:
+      n = GetCpuCount();
+      return n > 0 ? n : -1;
     default:
       return -1;
   }

libc/runtime/sysconf.h

@@ -1,15 +1,17 @@
 #ifndef COSMOPOLITAN_LIBC_RUNTIME_SYSCONF_H_
 #define COSMOPOLITAN_LIBC_RUNTIME_SYSCONF_H_
 
-#define _SC_ARG_MAX   0
-#define _SC_CLK_TCK   2
-#define _SC_PAGESIZE  30
-#define _SC_PAGE_SIZE 30
+#define _SC_ARG_MAX          0
+#define _SC_CLK_TCK          2
+#define _SC_PAGESIZE         30
+#define _SC_PAGE_SIZE        30
+#define _SC_NPROCESSORS_ONLN 1002
 
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
 long sysconf(int);
+unsigned GetCpuCount(void);
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */