Perform build and magnum tuning

Building o//third_party/python now takes 5 seconds on my PC

This change works towards modifying Python to use runtime dispatching
when appropriate. For example, when loading the magnums in the socket
module, it's a good idea to check if the magnum is zero, because that
means the local system platform doesn't support it.

third_party/python/Python/random.c

@@ -1,28 +1,6 @@
-#include "Python.h"
-#ifdef MS_WINDOWS
-#  include <windows.h>
-/* All sample MSDN wincrypt programs include the header below. It is at least
- * required with Min GW. */
-#  include <wincrypt.h>
-#else
-#  include <fcntl.h>
-#  ifdef HAVE_SYS_STAT_H
-#    include <sys/stat.h>
-#  endif
-#  ifdef HAVE_LINUX_RANDOM_H
-#    include <linux/random.h>
-#  endif
-#  if defined(HAVE_SYS_RANDOM_H) && (defined(HAVE_GETRANDOM) || defined(HAVE_GETENTROPY))
-#    include <sys/random.h>
-#  endif
-#  if !defined(HAVE_GETRANDOM) && defined(HAVE_GETRANDOM_SYSCALL)
-#    include <sys/syscall.h>
-#  endif
-#endif
-
-#ifdef _Py_MEMORY_SANITIZER
-#  include <sanitizer/msan_interface.h>
-#endif
+/* clang-format off */
+#include "libc/sysv/consts/grnd.h"
+#include "third_party/python/Include/Python.h"
 
 #ifdef Py_DEBUG
 int _Py_HashSecret_Initialized = 0;
@@ -30,59 +8,6 @@ int _Py_HashSecret_Initialized = 0;
 static int _Py_HashSecret_Initialized = 0;
 #endif
 
-#ifdef MS_WINDOWS
-static HCRYPTPROV hCryptProv = 0;
-
-static int
-win32_urandom_init(int raise)
-{
-    /* Acquire context */
-    if (!CryptAcquireContext(&hCryptProv, NULL, NULL,
-                             PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
-        goto error;
-
-    return 0;
-
-error:
-    if (raise) {
-        PyErr_SetFromWindowsErr(0);
-    }
-    return -1;
-}
-
-/* Fill buffer with size pseudo-random bytes generated by the Windows CryptoGen
-   API. Return 0 on success, or raise an exception and return -1 on error. */
-static int
-win32_urandom(unsigned char *buffer, Py_ssize_t size, int raise)
-{
-    Py_ssize_t chunk;
-
-    if (hCryptProv == 0)
-    {
-        if (win32_urandom_init(raise) == -1) {
-            return -1;
-        }
-    }
-
-    while (size > 0)
-    {
-        chunk = size > INT_MAX ? INT_MAX : size;
-        if (!CryptGenRandom(hCryptProv, (DWORD)chunk, buffer))
-        {
-            /* CryptGenRandom() failed */
-            if (raise) {
-                PyErr_SetFromWindowsErr(0);
-            }
-            return -1;
-        }
-        buffer += chunk;
-        size -= chunk;
-    }
-    return 0;
-}
-
-#else /* !MS_WINDOWS */
-
 #if defined(HAVE_GETRANDOM) || defined(HAVE_GETRANDOM_SYSCALL)
 #define PY_GETRANDOM 1
 
@@ -195,80 +120,6 @@ py_getrandom(void *buffer, Py_ssize_t size, int blocking, int raise)
     return 1;
 }
 
-#elif defined(HAVE_GETENTROPY)
-#define PY_GETENTROPY 1
-
-/* Fill buffer with size pseudo-random bytes generated by getentropy():
-
-   - Return 1 on success
-   - Return 0 if getentropy() syscall is not available (failed with ENOSYS or
-     EPERM).
-   - Raise an exception (if raise is non-zero) and return -1 on error:
-     if getentropy() failed with EINTR, raise is non-zero and the Python signal
-     handler raised an exception, or if getentropy() failed with a different
-     error.
-
-   getentropy() is retried if it failed with EINTR: interrupted by a signal. */
-static int
-py_getentropy(char *buffer, Py_ssize_t size, int raise)
-{
-    /* Is getentropy() supported by the running kernel? Set to 0 if
-       getentropy() failed with ENOSYS or EPERM. */
-    static int getentropy_works = 1;
-
-    if (!getentropy_works) {
-        return 0;
-    }
-
-    while (size > 0) {
-        /* getentropy() is limited to returning up to 256 bytes. Call it
-           multiple times if more bytes are requested. */
-        Py_ssize_t len = Py_MIN(size, 256);
-        int res;
-
-        if (raise) {
-            Py_BEGIN_ALLOW_THREADS
-            res = getentropy(buffer, len);
-            Py_END_ALLOW_THREADS
-        }
-        else {
-            res = getentropy(buffer, len);
-        }
-
-        if (res < 0) {
-            /* ENOSYS: the syscall is not supported by the running kernel.
-               EPERM: the syscall is blocked by a security policy (ex: SECCOMP)
-               or something else. */
-            if (errno == ENOSYS || errno == EPERM) {
-                getentropy_works = 0;
-                return 0;
-            }
-
-            if (errno == EINTR) {
-                if (raise) {
-                    if (PyErr_CheckSignals()) {
-                        return -1;
-                    }
-                }
-
-                /* retry getentropy() if it was interrupted by a signal */
-                continue;
-            }
-
-            if (raise) {
-                PyErr_SetFromErrno(PyExc_OSError);
-            }
-            return -1;
-        }
-
-        buffer += len;
-        size -= len;
-    }
-    return 1;
-}
-#endif /* defined(HAVE_GETENTROPY) && !defined(sun) */
-
-
 static struct {
     int fd;
     dev_t st_dev;
@@ -437,12 +288,9 @@ lcg_urandom(unsigned int x0, unsigned char *buffer, size_t size)
    - Return 0 on success
    - Raise an exception (if raise is non-zero) and return -1 on error
 
-   Used sources of entropy ordered by preference, preferred source first:
+   Used sources of entropy ordered by preference:
 
-   - CryptGenRandom() on Windows
-   - getrandom() function (ex: Linux and Solaris): call py_getrandom()
-   - getentropy() function (ex: OpenBSD): call py_getentropy()
-   - /dev/urandom device
+   - getrandom()
 
    Read from the /dev/urandom device if getrandom() or getentropy() function
    is not available or does not work.
@@ -499,11 +347,7 @@ pyurandom(void *buffer, Py_ssize_t size, int blocking, int raise)
 #else
 
 #if defined(PY_GETRANDOM) || defined(PY_GETENTROPY)
-#ifdef PY_GETRANDOM
     res = py_getrandom(buffer, size, blocking, raise);
-#else
-    res = py_getentropy(buffer, size, raise);
-#endif
     if (res < 0) {
         return -1;
     }