bpo-41100: add runtime checks for MACOSX_DEPLOYMENT_TARGET=10.10

Include/py_available.h

@@ -0,0 +1,49 @@
+#ifndef Py_AVAILABLE_H
+#define Py_AVAILABLE_H
+
+#include "Python.h"
+
+#ifdef __has_builtin
+#if __has_builtin(__builtin_available)
+#define HAVE_BUILTIN_AVAILABLE 1
+#endif
+#endif
+
+#if __APPLE__ && HAVE_BUILTIN_AVAILABLE
+#define HAVE_UTIMENSAT_RUNTIME          __builtin_available(macos 10.13, ios 11, tvos 11, watchos 4, *)
+#define HAVE_FUTIMENS_RUNTIME           __builtin_available(macos 10.13, ios 11, tvos 11, watchos 4, *)
+#define HAVE_PREADV_RUNTIME             __builtin_available(macos 11.0,  ios 14, tvos 14, watchos 7, *)
+#define HAVE_PWRITEV_RUNTIME            __builtin_available(macos 11.0,  ios 14, tvos 14, watchos 7, *)
+#define HAVE_POSIX_SPAWN_SETSID_RUNTIME __builtin_available(macos 10.15, ios 13, tvos 13, watchos 6, *)
+#define HAVE_CLOCK_GETTIME_RUNTIME      __builtin_available(macos 10.12, ios 10, tvos 10, watchos 3, *)
+#define HAVE_CLOCK_SETTIME_RUNTIME      __builtin_available(macos 10.12, ios 10, tvos 10, watchos 3, *)
+#define HAVE_CLOCK_GETRES_RUNTIME       __builtin_available(macos 10.12, ios 10, tvos 10, watchos 3, *)
+#define HAVE_GETENTROPY_RUNTIME         __builtin_available(macos 10.12, ios 10, tvos 10, watchos 3, *)
+#else
+#define HAVE_UTIMENSAT_RUNTIME 1
+#define HAVE_FUTIMENS_RUNTIME 1
+#define HAVE_PREADV_RUNTIME 1
+#define HAVE_PWRITEV_RUNTIME 1
+#define HAVE_POSIX_SPAWN_SETSID_RUNTIME 1
+#define HAVE_CLOCK_GETTIME_RUNTIME 1
+#define HAVE_CLOCK_SETTIME_RUNTIME 1
+#define HAVE_CLOCK_GETRES_RUNTIME 1
+#define HAVE_GETENTROPY_RUNTIME 1
+#endif
+
+static inline void
+Py_delete_method(PyMethodDef *methods, size_t size, const char *name)
+{
+    int last_method_index = (size /sizeof(PyMethodDef)) - 1;
+    for (int i = last_method_index; i >= 0; i--) {
+        if ( methods[i].ml_name && 0==strcmp(methods[i].ml_name, name)) {
+            for (int j = i; methods[j].ml_name != NULL; j++) {
+                methods[j] = methods[j+1];
+            }
+            break;
+        }
+    }
+}
+
+#endif
+

Misc/NEWS.d/next/macOS/2020-07-21-06-03-19.bpo-41100.6Et7be.rst

@@ -0,0 +1 @@
+Add runtime checks so python can be built for Mac OS 10.10 using the latest Xcode

Modules/posixmodule.c

@@ -42,6 +42,7 @@
 #else
 #  include "winreparse.h"
 #endif
+#include "py_available.h"
 
 /* On android API level 21, 'AT_EACCESS' is not declared although
  * HAVE_FACCESSAT is defined. */
@@ -4826,9 +4827,14 @@ static int
 utime_dir_fd(utime_t *ut, int dir_fd, const char *path, int follow_symlinks)
 {
 #ifdef HAVE_UTIMENSAT
-    int flags = follow_symlinks ? 0 : AT_SYMLINK_NOFOLLOW;
-    UTIME_TO_TIMESPEC;
-    return utimensat(dir_fd, path, time, flags);
+    if (HAVE_UTIMENSAT_RUNTIME) {
+        int flags = follow_symlinks ? 0 : AT_SYMLINK_NOFOLLOW;
+        UTIME_TO_TIMESPEC;
+        return utimensat(dir_fd, path, time, flags);
+    } else {
+        PyErr_SetString(PyExc_NotImplementedError, "utimensat is not available");
+        return -1;
+    }
 #elif defined(HAVE_FUTIMESAT)
     UTIME_TO_TIMEVAL;
     /*
@@ -4841,7 +4847,16 @@ utime_dir_fd(utime_t *ut, int dir_fd, const char *path, int follow_symlinks)
 #endif
 }
 
-    #define FUTIMENSAT_DIR_FD_CONVERTER dir_fd_converter
+static int
+utime_dir_fd_converter(PyObject *o, void *p)
+{
+    if (HAVE_UTIMENSAT_RUNTIME)
+        return dir_fd_converter(o,p);
+    else
+        return dir_fd_unavailable(o, p);
+}
+
+    #define FUTIMENSAT_DIR_FD_CONVERTER utime_dir_fd_converter
 #else
     #define FUTIMENSAT_DIR_FD_CONVERTER dir_fd_unavailable
 #endif
@@ -4852,12 +4867,15 @@ static int
 utime_fd(utime_t *ut, int fd)
 {
 #ifdef HAVE_FUTIMENS
-    UTIME_TO_TIMESPEC;
-    return futimens(fd, time);
-#else
-    UTIME_TO_TIMEVAL;
-    return futimes(fd, time);
+    if (HAVE_FUTIMENS_RUNTIME) {
+        UTIME_TO_TIMESPEC;
+        return futimens(fd, time);
+    } else
 #endif
+    {
+        UTIME_TO_TIMEVAL;
+        return futimes(fd, time);
+    }
 }
 
     #define PATH_UTIME_HAVE_FD 1
@@ -4875,12 +4893,15 @@ static int
 utime_nofollow_symlinks(utime_t *ut, const char *path)
 {
 #ifdef HAVE_UTIMENSAT
-    UTIME_TO_TIMESPEC;
-    return utimensat(DEFAULT_DIR_FD, path, time, AT_SYMLINK_NOFOLLOW);
-#else
-    UTIME_TO_TIMEVAL;
-    return lutimes(path, time);
+    if (HAVE_FUTIMENS_RUNTIME) {
+        UTIME_TO_TIMESPEC;
+        return utimensat(DEFAULT_DIR_FD, path, time, AT_SYMLINK_NOFOLLOW);
+    } else
 #endif
+    {
+        UTIME_TO_TIMEVAL;
+        return lutimes(path, time);
+    }
 }
 
 #endif
@@ -4891,9 +4912,12 @@ static int
 utime_default(utime_t *ut, const char *path)
 {
 #ifdef HAVE_UTIMENSAT
-    UTIME_TO_TIMESPEC;
-    return utimensat(DEFAULT_DIR_FD, path, time, 0);
-#elif defined(HAVE_UTIMES)
+    if (HAVE_UTIMENSAT_RUNTIME) {
+        UTIME_TO_TIMESPEC;
+        return utimensat(DEFAULT_DIR_FD, path, time, 0);
+    }
+#endif
+#if defined(HAVE_UTIMES)
     UTIME_TO_TIMEVAL;
     return utimes(path, time);
 #elif defined(HAVE_UTIME_H)
@@ -5513,7 +5537,12 @@ parse_posix_spawn_flags(PyObject *module, const char *func_name, PyObject *setpg
 
     if (setsid) {
 #ifdef POSIX_SPAWN_SETSID
-        all_flags |= POSIX_SPAWN_SETSID;
+        if (HAVE_POSIX_SPAWN_SETSID_RUNTIME) {
+            all_flags |= POSIX_SPAWN_SETSID;
+        } else {
+            argument_unavailable_error(func_name, "setsid");
+            return -1;
+        }
 #elif defined(POSIX_SPAWN_SETSID_NP)
         all_flags |= POSIX_SPAWN_SETSID_NP;
 #else
@@ -7168,7 +7197,8 @@ os_getgroups_impl(PyObject *module)
      * always first call getgroups with length 0 to get the actual number
      * of groups.
      */
-    n = getgroups(0, NULL);
+    /* getgroups will not fill the last slot with a gid, so we need +1 */
+    n = getgroups(0, NULL) + 1;
     if (n < 0) {
         return posix_error();
     } else if (n <= MAX_GROUPS) {
@@ -9255,6 +9285,12 @@ os_preadv_impl(PyObject *module, int fd, PyObject *buffers, Py_off_t offset,
                int flags)
 /*[clinic end generated code: output=26fc9c6e58e7ada5 input=4173919dc1f7ed99]*/
 {
+    /* preadv method will be deleted if preadv is not available */
+    #if __clang__
+    #pragma clang diagnostic push
+    #pragma clang diagnostic ignored "-Wunguarded-availability-new"
+    #endif
+
     Py_ssize_t cnt, n;
     int async_err = 0;
     struct iovec *iov;
@@ -9308,6 +9344,10 @@ os_preadv_impl(PyObject *module, int fd, PyObject *buffers, Py_off_t offset,
     }
 
     return n;
+
+    #if __clang__
+    #pragma clang diagnostic pop
+    #endif
 }
 #endif /* HAVE_PREADV */
 
@@ -9850,6 +9890,12 @@ os_pwritev_impl(PyObject *module, int fd, PyObject *buffers, Py_off_t offset,
                 int flags)
 /*[clinic end generated code: output=e3dd3e9d11a6a5c7 input=35358c327e1a2a8e]*/
 {
+    /* pwritev method will be deleted if preadv is not available */
+    #if __clang__
+    #pragma clang diagnostic push
+    #pragma clang diagnostic ignored "-Wunguarded-availability-new"
+    #endif
+
     Py_ssize_t cnt;
     Py_ssize_t result;
     int async_err = 0;
@@ -9904,6 +9950,10 @@ os_pwritev_impl(PyObject *module, int fd, PyObject *buffers, Py_off_t offset,
     }
 
     return result;
+
+    #if __clang__
+    #pragma clang diagnostic pop
+    #endif
 }
 #endif /* HAVE_PWRITEV */
 
@@ -14156,9 +14206,7 @@ static PyMethodDef posix_methods[] = {
     OS_READ_METHODDEF
     OS_READV_METHODDEF
     OS_PREAD_METHODDEF
-    OS_PREADV_METHODDEF
     OS_WRITE_METHODDEF
-    OS_WRITEV_METHODDEF
     OS_PWRITE_METHODDEF
     OS_PWRITEV_METHODDEF
     OS_SENDFILE_METHODDEF
@@ -14228,6 +14276,9 @@ static PyMethodDef posix_methods[] = {
     OS__ADD_DLL_DIRECTORY_METHODDEF
     OS__REMOVE_DLL_DIRECTORY_METHODDEF
     OS_WAITSTATUS_TO_EXITCODE_METHODDEF
+
+    OS_PREADV_METHODDEF
+    OS_WRITEV_METHODDEF
     {NULL,              NULL}            /* Sentinel */
 };
 
@@ -15070,6 +15121,10 @@ posixmodule_exec(PyObject *m)
         return -1;
     }
     for (const char * const *trace = have_functions; *trace; trace++) {
+        if (HAVE_UTIMENSAT_RUNTIME) {} else if (0==strcmp(*trace, "HAVE_UTIMENSAT")) continue;
+        if (HAVE_FUTIMENS_RUNTIME) {} else if (0==strcmp(*trace, "HAVE_FUTIMENS")) continue;
+        if (HAVE_PREADV_RUNTIME) {} else if (0==strcmp(*trace, "HAVE_PREADV")) continue;
+        if (HAVE_PWRITEV_RUNTIME) {} else if (0==strcmp(*trace, "HAVE_PWRITEV")) continue;
         PyObject *unicode = PyUnicode_DecodeASCII(*trace, strlen(*trace), NULL);
         if (!unicode)
             return -1;
@@ -15100,9 +15155,21 @@ static struct PyModuleDef posixmodule = {
     .m_free = _posix_free,
 };
 
+static void
+delete_method(const char *name)
+{
+    Py_delete_method(posix_methods, sizeof(posix_methods), name);
+}
+
 PyMODINIT_FUNC
 INITFUNC(void)
 {
+    #ifdef HAVE_PREADV
+    if (HAVE_PREADV_RUNTIME) {} else { delete_method("preadv"); }
+    #endif
+    #ifdef HAVE_PWRITEV
+    if (HAVE_PWRITEV_RUNTIME) {} else { delete_method("pwritev"); }
+    #endif
     return PyModuleDef_Init(&posixmodule);
 }