Sync contrib/tools/python3 layout with upstream

* Move src/ subdir contents to the top of the layout
* Rename self-written lib -> lib2 to avoid CaseFolding warning from the VCS
* Regenerate contrib/libs/python proxy-headers accordingly
4ccc62ac1511abcf0fed14ccade38e984e088f1e

1 files changed, 80 insertions, 0 deletions

diff --git a/contrib/tools/python3/Python/mysnprintf.c b/contrib/tools/python3/Python/mysnprintf.c
new file mode 100644
index 0000000000..2a505d14f8
--- /dev/null
+++ b/contrib/tools/python3/Python/mysnprintf.c
@@ -0,0 +1,80 @@
+#include "Python.h"
+
+/* snprintf() and vsnprintf() wrappers.
+
+   If the platform has vsnprintf, we use it, else we
+   emulate it in a half-hearted way.  Even if the platform has it, we wrap
+   it because platforms differ in what vsnprintf does in case the buffer
+   is too small:  C99 behavior is to return the number of characters that
+   would have been written had the buffer not been too small, and to set
+   the last byte of the buffer to \0.  At least MS _vsnprintf returns a
+   negative value instead, and fills the entire buffer with non-\0 data.
+   Unlike C99, our wrappers do not support passing a null buffer.
+
+   The wrappers ensure that str[size-1] is always \0 upon return.
+
+   PyOS_snprintf and PyOS_vsnprintf never write more than size bytes
+   (including the trailing '\0') into str.
+
+   Return value (rv):
+
+    When 0 <= rv < size, the output conversion was unexceptional, and
+    rv characters were written to str (excluding a trailing \0 byte at
+    str[rv]).
+
+    When rv >= size, output conversion was truncated, and a buffer of
+    size rv+1 would have been needed to avoid truncation.  str[size-1]
+    is \0 in this case.
+
+    When rv < 0, "something bad happened".  str[size-1] is \0 in this
+    case too, but the rest of str is unreliable.  It could be that
+    an error in format codes was detected by libc, or on platforms
+    with a non-C99 vsnprintf simply that the buffer wasn't big enough
+    to avoid truncation, or on platforms without any vsnprintf that
+    PyMem_Malloc couldn't obtain space for a temp buffer.
+
+   CAUTION:  Unlike C99, str != NULL and size > 0 are required.
+   Also, size must be smaller than INT_MAX.
+*/
+
+int
+PyOS_snprintf(char *str, size_t size, const  char  *format, ...)
+{
+    int rc;
+    va_list va;
+
+    va_start(va, format);
+    rc = PyOS_vsnprintf(str, size, format, va);
+    va_end(va);
+    return rc;
+}
+
+int
+PyOS_vsnprintf(char *str, size_t size, const char  *format, va_list va)
+{
+    assert(str != NULL);
+    assert(size > 0);
+    assert(size <= (INT_MAX - 1));
+    assert(format != NULL);
+
+    int len;  /* # bytes written, excluding \0 */
+    /* We take a size_t as input but return an int.  Sanity check
+     * our input so that it won't cause an overflow in the
+     * vsnprintf return value.  */
+    if (size > INT_MAX - 1) {
+        len = -666;
+        goto Done;
+    }
+
+#if defined(_MSC_VER)
+    len = _vsnprintf(str, size, format, va);
+#else
+    len = vsnprintf(str, size, format, va);
+#endif
+
+Done:
+    if (size > 0) {
+        str[size-1] = '\0';
+    }
+    return len;
+}