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, 1623 insertions, 0 deletions

diff --git a/contrib/tools/python3/Python/formatter_unicode.c b/contrib/tools/python3/Python/formatter_unicode.c
new file mode 100644
index 0000000000..38e5f69bfb
--- /dev/null
+++ b/contrib/tools/python3/Python/formatter_unicode.c
@@ -0,0 +1,1623 @@
+/* implements the unicode (as opposed to string) version of the
+   built-in formatters for string, int, float.  that is, the versions
+   of int.__float__, etc., that take and return unicode objects */
+
+#include "Python.h"
+#include "pycore_fileutils.h"     // _Py_GetLocaleconvNumeric()
+#include "pycore_long.h"          // _PyLong_FormatWriter()
+#include <locale.h>
+
+/* Raises an exception about an unknown presentation type for this
+ * type. */
+
+static void
+unknown_presentation_type(Py_UCS4 presentation_type,
+                          const char* type_name)
+{
+    /* %c might be out-of-range, hence the two cases. */
+    if (presentation_type > 32 && presentation_type < 128)
+        PyErr_Format(PyExc_ValueError,
+                     "Unknown format code '%c' "
+                     "for object of type '%.200s'",
+                     (char)presentation_type,
+                     type_name);
+    else
+        PyErr_Format(PyExc_ValueError,
+                     "Unknown format code '\\x%x' "
+                     "for object of type '%.200s'",
+                     (unsigned int)presentation_type,
+                     type_name);
+}
+
+static void
+invalid_thousands_separator_type(char specifier, Py_UCS4 presentation_type)
+{
+    assert(specifier == ',' || specifier == '_');
+    if (presentation_type > 32 && presentation_type < 128)
+        PyErr_Format(PyExc_ValueError,
+                     "Cannot specify '%c' with '%c'.",
+                     specifier, (char)presentation_type);
+    else
+        PyErr_Format(PyExc_ValueError,
+                     "Cannot specify '%c' with '\\x%x'.",
+                     specifier, (unsigned int)presentation_type);
+}
+
+static void
+invalid_comma_and_underscore(void)
+{
+    PyErr_Format(PyExc_ValueError, "Cannot specify both ',' and '_'.");
+}
+
+/*
+    get_integer consumes 0 or more decimal digit characters from an
+    input string, updates *result with the corresponding positive
+    integer, and returns the number of digits consumed.
+
+    returns -1 on error.
+*/
+static int
+get_integer(PyObject *str, Py_ssize_t *ppos, Py_ssize_t end,
+                  Py_ssize_t *result)
+{
+    Py_ssize_t accumulator, digitval, pos = *ppos;
+    int numdigits;
+    int kind = PyUnicode_KIND(str);
+    const void *data = PyUnicode_DATA(str);
+
+    accumulator = numdigits = 0;
+    for (; pos < end; pos++, numdigits++) {
+        digitval = Py_UNICODE_TODECIMAL(PyUnicode_READ(kind, data, pos));
+        if (digitval < 0)
+            break;
+        /*
+           Detect possible overflow before it happens:
+
+              accumulator * 10 + digitval > PY_SSIZE_T_MAX if and only if
+              accumulator > (PY_SSIZE_T_MAX - digitval) / 10.
+        */
+        if (accumulator > (PY_SSIZE_T_MAX - digitval) / 10) {
+            PyErr_Format(PyExc_ValueError,
+                         "Too many decimal digits in format string");
+            *ppos = pos;
+            return -1;
+        }
+        accumulator = accumulator * 10 + digitval;
+    }
+    *ppos = pos;
+    *result = accumulator;
+    return numdigits;
+}
+
+/************************************************************************/
+/*********** standard format specifier parsing **************************/
+/************************************************************************/
+
+/* returns true if this character is a specifier alignment token */
+Py_LOCAL_INLINE(int)
+is_alignment_token(Py_UCS4 c)
+{
+    switch (c) {
+    case '<': case '>': case '=': case '^':
+        return 1;
+    default:
+        return 0;
+    }
+}
+
+/* returns true if this character is a sign element */
+Py_LOCAL_INLINE(int)
+is_sign_element(Py_UCS4 c)
+{
+    switch (c) {
+    case ' ': case '+': case '-':
+        return 1;
+    default:
+        return 0;
+    }
+}
+
+/* Locale type codes. LT_NO_LOCALE must be zero. */
+enum LocaleType {
+    LT_NO_LOCALE = 0,
+    LT_DEFAULT_LOCALE = ',',
+    LT_UNDERSCORE_LOCALE = '_',
+    LT_UNDER_FOUR_LOCALE,
+    LT_CURRENT_LOCALE
+};
+
+typedef struct {
+    Py_UCS4 fill_char;
+    Py_UCS4 align;
+    int alternate;
+    int no_neg_0;
+    Py_UCS4 sign;
+    Py_ssize_t width;
+    enum LocaleType thousands_separators;
+    Py_ssize_t precision;
+    Py_UCS4 type;
+} InternalFormatSpec;
+
+
+/*
+  ptr points to the start of the format_spec, end points just past its end.
+  fills in format with the parsed information.
+  returns 1 on success, 0 on failure.
+  if failure, sets the exception
+*/
+static int
+parse_internal_render_format_spec(PyObject *obj,
+                                  PyObject *format_spec,
+                                  Py_ssize_t start, Py_ssize_t end,
+                                  InternalFormatSpec *format,
+                                  char default_type,
+                                  char default_align)
+{
+    Py_ssize_t pos = start;
+    int kind = PyUnicode_KIND(format_spec);
+    const void *data = PyUnicode_DATA(format_spec);
+    /* end-pos is used throughout this code to specify the length of
+       the input string */
+#define READ_spec(index) PyUnicode_READ(kind, data, index)
+
+    Py_ssize_t consumed;
+    int align_specified = 0;
+    int fill_char_specified = 0;
+
+    format->fill_char = ' ';
+    format->align = default_align;
+    format->alternate = 0;
+    format->no_neg_0 = 0;
+    format->sign = '\0';
+    format->width = -1;
+    format->thousands_separators = LT_NO_LOCALE;
+    format->precision = -1;
+    format->type = default_type;
+
+    /* If the second char is an alignment token,
+       then parse the fill char */
+    if (end-pos >= 2 && is_alignment_token(READ_spec(pos+1))) {
+        format->align = READ_spec(pos+1);
+        format->fill_char = READ_spec(pos);
+        fill_char_specified = 1;
+        align_specified = 1;
+        pos += 2;
+    }
+    else if (end-pos >= 1 && is_alignment_token(READ_spec(pos))) {
+        format->align = READ_spec(pos);
+        align_specified = 1;
+        ++pos;
+    }
+
+    /* Parse the various sign options */
+    if (end-pos >= 1 && is_sign_element(READ_spec(pos))) {
+        format->sign = READ_spec(pos);
+        ++pos;
+    }
+
+    /* If the next character is z, request coercion of negative 0.
+       Applies only to floats. */
+    if (end-pos >= 1 && READ_spec(pos) == 'z') {
+        format->no_neg_0 = 1;
+        ++pos;
+    }
+
+    /* If the next character is #, we're in alternate mode.  This only
+       applies to integers. */
+    if (end-pos >= 1 && READ_spec(pos) == '#') {
+        format->alternate = 1;
+        ++pos;
+    }
+
+    /* The special case for 0-padding (backwards compat) */
+    if (!fill_char_specified && end-pos >= 1 && READ_spec(pos) == '0') {
+        format->fill_char = '0';
+        if (!align_specified && default_align == '>') {
+            format->align = '=';
+        }
+        ++pos;
+    }
+
+    consumed = get_integer(format_spec, &pos, end, &format->width);
+    if (consumed == -1)
+        /* Overflow error. Exception already set. */
+        return 0;
+
+    /* If consumed is 0, we didn't consume any characters for the
+       width. In that case, reset the width to -1, because
+       get_integer() will have set it to zero. -1 is how we record
+       that the width wasn't specified. */
+    if (consumed == 0)
+        format->width = -1;
+
+    /* Comma signifies add thousands separators */
+    if (end-pos && READ_spec(pos) == ',') {
+        format->thousands_separators = LT_DEFAULT_LOCALE;
+        ++pos;
+    }
+    /* Underscore signifies add thousands separators */
+    if (end-pos && READ_spec(pos) == '_') {
+        if (format->thousands_separators != LT_NO_LOCALE) {
+            invalid_comma_and_underscore();
+            return 0;
+        }
+        format->thousands_separators = LT_UNDERSCORE_LOCALE;
+        ++pos;
+    }
+    if (end-pos && READ_spec(pos) == ',') {
+        if (format->thousands_separators == LT_UNDERSCORE_LOCALE) {
+            invalid_comma_and_underscore();
+            return 0;
+        }
+    }
+
+    /* Parse field precision */
+    if (end-pos && READ_spec(pos) == '.') {
+        ++pos;
+
+        consumed = get_integer(format_spec, &pos, end, &format->precision);
+        if (consumed == -1)
+            /* Overflow error. Exception already set. */
+            return 0;
+
+        /* Not having a precision after a dot is an error. */
+        if (consumed == 0) {
+            PyErr_Format(PyExc_ValueError,
+                         "Format specifier missing precision");
+            return 0;
+        }
+
+    }
+
+    /* Finally, parse the type field. */
+
+    if (end-pos > 1) {
+        /* More than one char remains, so this is an invalid format
+           specifier. */
+        /* Create a temporary object that contains the format spec we're
+           operating on.  It's format_spec[start:end] (in Python syntax). */
+        PyObject* actual_format_spec = PyUnicode_FromKindAndData(kind,
+                                         (char*)data + kind*start,
+                                         end-start);
+        if (actual_format_spec != NULL) {
+            PyErr_Format(PyExc_ValueError,
+                "Invalid format specifier '%U' for object of type '%.200s'",
+                actual_format_spec, Py_TYPE(obj)->tp_name);
+            Py_DECREF(actual_format_spec);
+        }
+        return 0;
+    }
+
+    if (end-pos == 1) {
+        format->type = READ_spec(pos);
+        ++pos;
+    }
+
+    /* Do as much validating as we can, just by looking at the format
+       specifier.  Do not take into account what type of formatting
+       we're doing (int, float, string). */
+
+    if (format->thousands_separators) {
+        switch (format->type) {
+        case 'd':
+        case 'e':
+        case 'f':
+        case 'g':
+        case 'E':
+        case 'G':
+        case '%':
+        case 'F':
+        case '\0':
+            /* These are allowed. See PEP 378.*/
+            break;
+        case 'b':
+        case 'o':
+        case 'x':
+        case 'X':
+            /* Underscores are allowed in bin/oct/hex. See PEP 515. */
+            if (format->thousands_separators == LT_UNDERSCORE_LOCALE) {
+                /* Every four digits, not every three, in bin/oct/hex. */
+                format->thousands_separators = LT_UNDER_FOUR_LOCALE;
+                break;
+            }
+            /* fall through */
+        default:
+            invalid_thousands_separator_type(format->thousands_separators, format->type);
+            return 0;
+        }
+    }
+
+    assert (format->align <= 127);
+    assert (format->sign <= 127);
+    return 1;
+}
+
+/* Calculate the padding needed. */
+static void
+calc_padding(Py_ssize_t nchars, Py_ssize_t width, Py_UCS4 align,
+             Py_ssize_t *n_lpadding, Py_ssize_t *n_rpadding,
+             Py_ssize_t *n_total)
+{
+    if (width >= 0) {
+        if (nchars > width)
+            *n_total = nchars;
+        else
+            *n_total = width;
+    }
+    else {
+        /* not specified, use all of the chars and no more */
+        *n_total = nchars;
+    }
+
+    /* Figure out how much leading space we need, based on the
+       aligning */
+    if (align == '>')
+        *n_lpadding = *n_total - nchars;
+    else if (align == '^')
+        *n_lpadding = (*n_total - nchars) / 2;
+    else if (align == '<' || align == '=')
+        *n_lpadding = 0;
+    else {
+        /* We should never have an unspecified alignment. */
+        Py_UNREACHABLE();
+    }
+
+    *n_rpadding = *n_total - nchars - *n_lpadding;
+}
+
+/* Do the padding, and return a pointer to where the caller-supplied
+   content goes. */
+static int
+fill_padding(_PyUnicodeWriter *writer,
+             Py_ssize_t nchars,
+             Py_UCS4 fill_char, Py_ssize_t n_lpadding,
+             Py_ssize_t n_rpadding)
+{
+    Py_ssize_t pos;
+
+    /* Pad on left. */
+    if (n_lpadding) {
+        pos = writer->pos;
+        _PyUnicode_FastFill(writer->buffer, pos, n_lpadding, fill_char);
+    }
+
+    /* Pad on right. */
+    if (n_rpadding) {
+        pos = writer->pos + nchars + n_lpadding;
+        _PyUnicode_FastFill(writer->buffer, pos, n_rpadding, fill_char);
+    }
+
+    /* Pointer to the user content. */
+    writer->pos += n_lpadding;
+    return 0;
+}
+
+/************************************************************************/
+/*********** common routines for numeric formatting *********************/
+/************************************************************************/
+
+/* Locale info needed for formatting integers and the part of floats
+   before and including the decimal. Note that locales only support
+   8-bit chars, not unicode. */
+typedef struct {
+    PyObject *decimal_point;
+    PyObject *thousands_sep;
+    const char *grouping;
+    char *grouping_buffer;
+} LocaleInfo;
+
+#define LocaleInfo_STATIC_INIT {0, 0, 0, 0}
+
+/* describes the layout for an integer, see the comment in
+   calc_number_widths() for details */
+typedef struct {
+    Py_ssize_t n_lpadding;
+    Py_ssize_t n_prefix;
+    Py_ssize_t n_spadding;
+    Py_ssize_t n_rpadding;
+    char sign;
+    Py_ssize_t n_sign;      /* number of digits needed for sign (0/1) */
+    Py_ssize_t n_grouped_digits; /* Space taken up by the digits, including
+                                    any grouping chars. */
+    Py_ssize_t n_decimal;   /* 0 if only an integer */
+    Py_ssize_t n_remainder; /* Digits in decimal and/or exponent part,
+                               excluding the decimal itself, if
+                               present. */
+
+    /* These 2 are not the widths of fields, but are needed by
+       STRINGLIB_GROUPING. */
+    Py_ssize_t n_digits;    /* The number of digits before a decimal
+                               or exponent. */
+    Py_ssize_t n_min_width; /* The min_width we used when we computed
+                               the n_grouped_digits width. */
+} NumberFieldWidths;
+
+
+/* Given a number of the form:
+   digits[remainder]
+   where ptr points to the start and end points to the end, find where
+    the integer part ends. This could be a decimal, an exponent, both,
+    or neither.
+   If a decimal point is present, set *has_decimal and increment
+    remainder beyond it.
+   Results are undefined (but shouldn't crash) for improperly
+    formatted strings.
+*/
+static void
+parse_number(PyObject *s, Py_ssize_t pos, Py_ssize_t end,
+             Py_ssize_t *n_remainder, int *has_decimal)
+{
+    Py_ssize_t remainder;
+    int kind = PyUnicode_KIND(s);
+    const void *data = PyUnicode_DATA(s);
+
+    while (pos<end && Py_ISDIGIT(PyUnicode_READ(kind, data, pos)))
+        ++pos;
+    remainder = pos;
+
+    /* Does remainder start with a decimal point? */
+    *has_decimal = pos<end && PyUnicode_READ(kind, data, remainder) == '.';
+
+    /* Skip the decimal point. */
+    if (*has_decimal)
+        remainder++;
+
+    *n_remainder = end - remainder;
+}
+
+/* not all fields of format are used.  for example, precision is
+   unused.  should this take discrete params in order to be more clear
+   about what it does?  or is passing a single format parameter easier
+   and more efficient enough to justify a little obfuscation?
+   Return -1 on error. */
+static Py_ssize_t
+calc_number_widths(NumberFieldWidths *spec, Py_ssize_t n_prefix,
+                   Py_UCS4 sign_char, Py_ssize_t n_start,
+                   Py_ssize_t n_end, Py_ssize_t n_remainder,
+                   int has_decimal, const LocaleInfo *locale,
+                   const InternalFormatSpec *format, Py_UCS4 *maxchar)
+{
+    Py_ssize_t n_non_digit_non_padding;
+    Py_ssize_t n_padding;
+
+    spec->n_digits = n_end - n_start - n_remainder - (has_decimal?1:0);
+    spec->n_lpadding = 0;
+    spec->n_prefix = n_prefix;
+    spec->n_decimal = has_decimal ? PyUnicode_GET_LENGTH(locale->decimal_point) : 0;
+    spec->n_remainder = n_remainder;
+    spec->n_spadding = 0;
+    spec->n_rpadding = 0;
+    spec->sign = '\0';
+    spec->n_sign = 0;
+
+    /* the output will look like:
+       |                                                                                         |
+       | <lpadding> <sign> <prefix> <spadding> <grouped_digits> <decimal> <remainder> <rpadding> |
+       |                                                                                         |
+
+       sign is computed from format->sign and the actual
+       sign of the number
+
+       prefix is given (it's for the '0x' prefix)
+
+       digits is already known
+
+       the total width is either given, or computed from the
+       actual digits
+
+       only one of lpadding, spadding, and rpadding can be non-zero,
+       and it's calculated from the width and other fields
+    */
+
+    /* compute the various parts we're going to write */
+    switch (format->sign) {
+    case '+':
+        /* always put a + or - */
+        spec->n_sign = 1;
+        spec->sign = (sign_char == '-' ? '-' : '+');
+        break;
+    case ' ':
+        spec->n_sign = 1;
+        spec->sign = (sign_char == '-' ? '-' : ' ');
+        break;
+    default:
+        /* Not specified, or the default (-) */
+        if (sign_char == '-') {
+            spec->n_sign = 1;
+            spec->sign = '-';
+        }
+    }
+
+    /* The number of chars used for non-digits and non-padding. */
+    n_non_digit_non_padding = spec->n_sign + spec->n_prefix + spec->n_decimal +
+        spec->n_remainder;
+
+    /* min_width can go negative, that's okay. format->width == -1 means
+       we don't care. */
+    if (format->fill_char == '0' && format->align == '=')
+        spec->n_min_width = format->width - n_non_digit_non_padding;
+    else
+        spec->n_min_width = 0;
+
+    if (spec->n_digits == 0)
+        /* This case only occurs when using 'c' formatting, we need
+           to special case it because the grouping code always wants
+           to have at least one character. */
+        spec->n_grouped_digits = 0;
+    else {
+        Py_UCS4 grouping_maxchar;
+        spec->n_grouped_digits = _PyUnicode_InsertThousandsGrouping(
+            NULL, 0,
+            NULL, 0, spec->n_digits,
+            spec->n_min_width,
+            locale->grouping, locale->thousands_sep, &grouping_maxchar);
+        if (spec->n_grouped_digits == -1) {
+            return -1;
+        }
+        *maxchar = Py_MAX(*maxchar, grouping_maxchar);
+    }
+
+    /* Given the desired width and the total of digit and non-digit
+       space we consume, see if we need any padding. format->width can
+       be negative (meaning no padding), but this code still works in
+       that case. */
+    n_padding = format->width -
+                        (n_non_digit_non_padding + spec->n_grouped_digits);
+    if (n_padding > 0) {
+        /* Some padding is needed. Determine if it's left, space, or right. */
+        switch (format->align) {
+        case '<':
+            spec->n_rpadding = n_padding;
+            break;
+        case '^':
+            spec->n_lpadding = n_padding / 2;
+            spec->n_rpadding = n_padding - spec->n_lpadding;
+            break;
+        case '=':
+            spec->n_spadding = n_padding;
+            break;
+        case '>':
+            spec->n_lpadding = n_padding;
+            break;
+        default:
+            /* Shouldn't get here */
+            Py_UNREACHABLE();
+        }
+    }
+
+    if (spec->n_lpadding || spec->n_spadding || spec->n_rpadding)
+        *maxchar = Py_MAX(*maxchar, format->fill_char);
+
+    if (spec->n_decimal)
+        *maxchar = Py_MAX(*maxchar, PyUnicode_MAX_CHAR_VALUE(locale->decimal_point));
+
+    return spec->n_lpadding + spec->n_sign + spec->n_prefix +
+        spec->n_spadding + spec->n_grouped_digits + spec->n_decimal +
+        spec->n_remainder + spec->n_rpadding;
+}
+
+/* Fill in the digit parts of a number's string representation,
+   as determined in calc_number_widths().
+   Return -1 on error, or 0 on success. */
+static int
+fill_number(_PyUnicodeWriter *writer, const NumberFieldWidths *spec,
+            PyObject *digits, Py_ssize_t d_start,
+            PyObject *prefix, Py_ssize_t p_start,
+            Py_UCS4 fill_char,
+            LocaleInfo *locale, int toupper)
+{
+    /* Used to keep track of digits, decimal, and remainder. */
+    Py_ssize_t d_pos = d_start;
+    const int kind = writer->kind;
+    const void *data = writer->data;
+    Py_ssize_t r;
+
+    if (spec->n_lpadding) {
+        _PyUnicode_FastFill(writer->buffer,
+                            writer->pos, spec->n_lpadding, fill_char);
+        writer->pos += spec->n_lpadding;
+    }
+    if (spec->n_sign == 1) {
+        PyUnicode_WRITE(kind, data, writer->pos, spec->sign);
+        writer->pos++;
+    }
+    if (spec->n_prefix) {
+        _PyUnicode_FastCopyCharacters(writer->buffer, writer->pos,
+                                      prefix, p_start,
+                                      spec->n_prefix);
+        if (toupper) {
+            Py_ssize_t t;
+            for (t = 0; t < spec->n_prefix; t++) {
+                Py_UCS4 c = PyUnicode_READ(kind, data, writer->pos + t);
+                c = Py_TOUPPER(c);
+                assert (c <= 127);
+                PyUnicode_WRITE(kind, data, writer->pos + t, c);
+            }
+        }
+        writer->pos += spec->n_prefix;
+    }
+    if (spec->n_spadding) {
+        _PyUnicode_FastFill(writer->buffer,
+                            writer->pos, spec->n_spadding, fill_char);
+        writer->pos += spec->n_spadding;
+    }
+
+    /* Only for type 'c' special case, it has no digits. */
+    if (spec->n_digits != 0) {
+        /* Fill the digits with InsertThousandsGrouping. */
+        r = _PyUnicode_InsertThousandsGrouping(
+                writer, spec->n_grouped_digits,
+                digits, d_pos, spec->n_digits,
+                spec->n_min_width,
+                locale->grouping, locale->thousands_sep, NULL);
+        if (r == -1)
+            return -1;
+        assert(r == spec->n_grouped_digits);
+        d_pos += spec->n_digits;
+    }
+    if (toupper) {
+        Py_ssize_t t;
+        for (t = 0; t < spec->n_grouped_digits; t++) {
+            Py_UCS4 c = PyUnicode_READ(kind, data, writer->pos + t);
+            c = Py_TOUPPER(c);
+            if (c > 127) {
+                PyErr_SetString(PyExc_SystemError, "non-ascii grouped digit");
+                return -1;
+            }
+            PyUnicode_WRITE(kind, data, writer->pos + t, c);
+        }
+    }
+    writer->pos += spec->n_grouped_digits;
+
+    if (spec->n_decimal) {
+        _PyUnicode_FastCopyCharacters(
+            writer->buffer, writer->pos,
+            locale->decimal_point, 0, spec->n_decimal);
+        writer->pos += spec->n_decimal;
+        d_pos += 1;
+    }
+
+    if (spec->n_remainder) {
+        _PyUnicode_FastCopyCharacters(
+            writer->buffer, writer->pos,
+            digits, d_pos, spec->n_remainder);
+        writer->pos += spec->n_remainder;
+        /* d_pos += spec->n_remainder; */
+    }
+
+    if (spec->n_rpadding) {
+        _PyUnicode_FastFill(writer->buffer,
+                            writer->pos, spec->n_rpadding,
+                            fill_char);
+        writer->pos += spec->n_rpadding;
+    }
+    return 0;
+}
+
+static const char no_grouping[1] = {CHAR_MAX};
+
+/* Find the decimal point character(s?), thousands_separator(s?), and
+   grouping description, either for the current locale if type is
+   LT_CURRENT_LOCALE, a hard-coded locale if LT_DEFAULT_LOCALE or
+   LT_UNDERSCORE_LOCALE/LT_UNDER_FOUR_LOCALE, or none if LT_NO_LOCALE. */
+static int
+get_locale_info(enum LocaleType type, LocaleInfo *locale_info)
+{
+    switch (type) {
+    case LT_CURRENT_LOCALE: {
+        struct lconv *lc = localeconv();
+        if (_Py_GetLocaleconvNumeric(lc,
+                                     &locale_info->decimal_point,
+                                     &locale_info->thousands_sep) < 0) {
+            return -1;
+        }
+
+        /* localeconv() grouping can become a dangling pointer or point
+           to a different string if another thread calls localeconv() during
+           the string formatting. Copy the string to avoid this risk. */
+        locale_info->grouping_buffer = _PyMem_Strdup(lc->grouping);
+        if (locale_info->grouping_buffer == NULL) {
+            PyErr_NoMemory();
+            return -1;
+        }
+        locale_info->grouping = locale_info->grouping_buffer;
+        break;
+    }
+    case LT_DEFAULT_LOCALE:
+    case LT_UNDERSCORE_LOCALE:
+    case LT_UNDER_FOUR_LOCALE:
+        locale_info->decimal_point = PyUnicode_FromOrdinal('.');
+        locale_info->thousands_sep = PyUnicode_FromOrdinal(
+            type == LT_DEFAULT_LOCALE ? ',' : '_');
+        if (!locale_info->decimal_point || !locale_info->thousands_sep)
+            return -1;
+        if (type != LT_UNDER_FOUR_LOCALE)
+            locale_info->grouping = "\3"; /* Group every 3 characters.  The
+                                         (implicit) trailing 0 means repeat
+                                         infinitely. */
+        else
+            locale_info->grouping = "\4"; /* Bin/oct/hex group every four. */
+        break;
+    case LT_NO_LOCALE:
+        locale_info->decimal_point = PyUnicode_FromOrdinal('.');
+        locale_info->thousands_sep = PyUnicode_New(0, 0);
+        if (!locale_info->decimal_point || !locale_info->thousands_sep)
+            return -1;
+        locale_info->grouping = no_grouping;
+        break;
+    }
+    return 0;
+}
+
+static void
+free_locale_info(LocaleInfo *locale_info)
+{
+    Py_XDECREF(locale_info->decimal_point);
+    Py_XDECREF(locale_info->thousands_sep);
+    PyMem_Free(locale_info->grouping_buffer);
+}
+
+/************************************************************************/
+/*********** string formatting ******************************************/
+/************************************************************************/
+
+static int
+format_string_internal(PyObject *value, const InternalFormatSpec *format,
+                       _PyUnicodeWriter *writer)
+{
+    Py_ssize_t lpad;
+    Py_ssize_t rpad;
+    Py_ssize_t total;
+    Py_ssize_t len;
+    int result = -1;
+    Py_UCS4 maxchar;
+
+    assert(PyUnicode_IS_READY(value));
+    len = PyUnicode_GET_LENGTH(value);
+
+    /* sign is not allowed on strings */
+    if (format->sign != '\0') {
+        if (format->sign == ' ') {
+            PyErr_SetString(PyExc_ValueError,
+                "Space not allowed in string format specifier");
+        }
+        else {
+            PyErr_SetString(PyExc_ValueError,
+                "Sign not allowed in string format specifier");
+        }
+        goto done;
+    }
+
+    /* negative 0 coercion is not allowed on strings */
+    if (format->no_neg_0) {
+        PyErr_SetString(PyExc_ValueError,
+                        "Negative zero coercion (z) not allowed in string format "
+                        "specifier");
+        goto done;
+    }
+
+    /* alternate is not allowed on strings */
+    if (format->alternate) {
+        PyErr_SetString(PyExc_ValueError,
+                        "Alternate form (#) not allowed in string format "
+                        "specifier");
+        goto done;
+    }
+
+    /* '=' alignment not allowed on strings */
+    if (format->align == '=') {
+        PyErr_SetString(PyExc_ValueError,
+                        "'=' alignment not allowed "
+                        "in string format specifier");
+        goto done;
+    }
+
+    if ((format->width == -1 || format->width <= len)
+        && (format->precision == -1 || format->precision >= len)) {
+        /* Fast path */
+        return _PyUnicodeWriter_WriteStr(writer, value);
+    }
+
+    /* if precision is specified, output no more that format.precision
+       characters */
+    if (format->precision >= 0 && len >= format->precision) {
+        len = format->precision;
+    }
+
+    calc_padding(len, format->width, format->align, &lpad, &rpad, &total);
+
+    maxchar = writer->maxchar;
+    if (lpad != 0 || rpad != 0)
+        maxchar = Py_MAX(maxchar, format->fill_char);
+    if (PyUnicode_MAX_CHAR_VALUE(value) > maxchar) {
+        Py_UCS4 valmaxchar = _PyUnicode_FindMaxChar(value, 0, len);
+        maxchar = Py_MAX(maxchar, valmaxchar);
+    }
+
+    /* allocate the resulting string */
+    if (_PyUnicodeWriter_Prepare(writer, total, maxchar) == -1)
+        goto done;
+
+    /* Write into that space. First the padding. */
+    result = fill_padding(writer, len, format->fill_char, lpad, rpad);
+    if (result == -1)
+        goto done;
+
+    /* Then the source string. */
+    if (len) {
+        _PyUnicode_FastCopyCharacters(writer->buffer, writer->pos,
+                                      value, 0, len);
+    }
+    writer->pos += (len + rpad);
+    result = 0;
+
+done:
+    return result;
+}
+
+
+/************************************************************************/
+/*********** long formatting ********************************************/
+/************************************************************************/
+
+static int
+format_long_internal(PyObject *value, const InternalFormatSpec *format,
+                     _PyUnicodeWriter *writer)
+{
+    int result = -1;
+    Py_UCS4 maxchar = 127;
+    PyObject *tmp = NULL;
+    Py_ssize_t inumeric_chars;
+    Py_UCS4 sign_char = '\0';
+    Py_ssize_t n_digits;       /* count of digits need from the computed
+                                  string */
+    Py_ssize_t n_remainder = 0; /* Used only for 'c' formatting, which
+                                   produces non-digits */
+    Py_ssize_t n_prefix = 0;   /* Count of prefix chars, (e.g., '0x') */
+    Py_ssize_t n_total;
+    Py_ssize_t prefix = 0;
+    NumberFieldWidths spec;
+    long x;
+
+    /* Locale settings, either from the actual locale or
+       from a hard-code pseudo-locale */
+    LocaleInfo locale = LocaleInfo_STATIC_INIT;
+
+    /* no precision allowed on integers */
+    if (format->precision != -1) {
+        PyErr_SetString(PyExc_ValueError,
+                        "Precision not allowed in integer format specifier");
+        goto done;
+    }
+    /* no negative zero coercion on integers */
+    if (format->no_neg_0) {
+        PyErr_SetString(PyExc_ValueError,
+                        "Negative zero coercion (z) not allowed in integer"
+                        " format specifier");
+        goto done;
+    }
+
+    /* special case for character formatting */
+    if (format->type == 'c') {
+        /* error to specify a sign */
+        if (format->sign != '\0') {
+            PyErr_SetString(PyExc_ValueError,
+                            "Sign not allowed with integer"
+                            " format specifier 'c'");
+            goto done;
+        }
+        /* error to request alternate format */
+        if (format->alternate) {
+            PyErr_SetString(PyExc_ValueError,
+                            "Alternate form (#) not allowed with integer"
+                            " format specifier 'c'");
+            goto done;
+        }
+
+        /* taken from unicodeobject.c formatchar() */
+        /* Integer input truncated to a character */
+        x = PyLong_AsLong(value);
+        if (x == -1 && PyErr_Occurred())
+            goto done;
+        if (x < 0 || x > 0x10ffff) {
+            PyErr_SetString(PyExc_OverflowError,
+                            "%c arg not in range(0x110000)");
+            goto done;
+        }
+        tmp = PyUnicode_FromOrdinal(x);
+        inumeric_chars = 0;
+        n_digits = 1;
+        maxchar = Py_MAX(maxchar, (Py_UCS4)x);
+
+        /* As a sort-of hack, we tell calc_number_widths that we only
+           have "remainder" characters. calc_number_widths thinks
+           these are characters that don't get formatted, only copied
+           into the output string. We do this for 'c' formatting,
+           because the characters are likely to be non-digits. */
+        n_remainder = 1;
+    }
+    else {
+        int base;
+        int leading_chars_to_skip = 0;  /* Number of characters added by
+                                           PyNumber_ToBase that we want to
+                                           skip over. */
+
+        /* Compute the base and how many characters will be added by
+           PyNumber_ToBase */
+        switch (format->type) {
+        case 'b':
+            base = 2;
+            leading_chars_to_skip = 2; /* 0b */
+            break;
+        case 'o':
+            base = 8;
+            leading_chars_to_skip = 2; /* 0o */
+            break;
+        case 'x':
+        case 'X':
+            base = 16;
+            leading_chars_to_skip = 2; /* 0x */
+            break;
+        default:  /* shouldn't be needed, but stops a compiler warning */
+        case 'd':
+        case 'n':
+            base = 10;
+            break;
+        }
+
+        if (format->sign != '+' && format->sign != ' '
+            && format->width == -1
+            && format->type != 'X' && format->type != 'n'
+            && !format->thousands_separators
+            && PyLong_CheckExact(value))
+        {
+            /* Fast path */
+            return _PyLong_FormatWriter(writer, value, base, format->alternate);
+        }
+
+        /* The number of prefix chars is the same as the leading
+           chars to skip */
+        if (format->alternate)
+            n_prefix = leading_chars_to_skip;
+
+        /* Do the hard part, converting to a string in a given base */
+        tmp = _PyLong_Format(value, base);
+        if (tmp == NULL || PyUnicode_READY(tmp) == -1)
+            goto done;
+
+        inumeric_chars = 0;
+        n_digits = PyUnicode_GET_LENGTH(tmp);
+
+        prefix = inumeric_chars;
+
+        /* Is a sign character present in the output?  If so, remember it
+           and skip it */
+        if (PyUnicode_READ_CHAR(tmp, inumeric_chars) == '-') {
+            sign_char = '-';
+            ++prefix;
+            ++leading_chars_to_skip;
+        }
+
+        /* Skip over the leading chars (0x, 0b, etc.) */
+        n_digits -= leading_chars_to_skip;
+        inumeric_chars += leading_chars_to_skip;
+    }
+
+    /* Determine the grouping, separator, and decimal point, if any. */
+    if (get_locale_info(format->type == 'n' ? LT_CURRENT_LOCALE :
+                        format->thousands_separators,
+                        &locale) == -1)
+        goto done;
+
+    /* Calculate how much memory we'll need. */
+    n_total = calc_number_widths(&spec, n_prefix, sign_char, inumeric_chars,
+                                 inumeric_chars + n_digits, n_remainder, 0,
+                                 &locale, format, &maxchar);
+    if (n_total == -1) {
+        goto done;
+    }
+
+    /* Allocate the memory. */
+    if (_PyUnicodeWriter_Prepare(writer, n_total, maxchar) == -1)
+        goto done;
+
+    /* Populate the memory. */
+    result = fill_number(writer, &spec,
+                         tmp, inumeric_chars,
+                         tmp, prefix, format->fill_char,
+                         &locale, format->type == 'X');
+
+done:
+    Py_XDECREF(tmp);
+    free_locale_info(&locale);
+    return result;
+}
+
+/************************************************************************/
+/*********** float formatting *******************************************/
+/************************************************************************/
+
+/* much of this is taken from unicodeobject.c */
+static int
+format_float_internal(PyObject *value,
+                      const InternalFormatSpec *format,
+                      _PyUnicodeWriter *writer)
+{
+    char *buf = NULL;       /* buffer returned from PyOS_double_to_string */
+    Py_ssize_t n_digits;
+    Py_ssize_t n_remainder;
+    Py_ssize_t n_total;
+    int has_decimal;
+    double val;
+    int precision, default_precision = 6;
+    Py_UCS4 type = format->type;
+    int add_pct = 0;
+    Py_ssize_t index;
+    NumberFieldWidths spec;
+    int flags = 0;
+    int result = -1;
+    Py_UCS4 maxchar = 127;
+    Py_UCS4 sign_char = '\0';
+    int float_type; /* Used to see if we have a nan, inf, or regular float. */
+    PyObject *unicode_tmp = NULL;
+
+    /* Locale settings, either from the actual locale or
+       from a hard-code pseudo-locale */
+    LocaleInfo locale = LocaleInfo_STATIC_INIT;
+
+    if (format->precision > INT_MAX) {
+        PyErr_SetString(PyExc_ValueError, "precision too big");
+        goto done;
+    }
+    precision = (int)format->precision;
+
+    if (format->alternate)
+        flags |= Py_DTSF_ALT;
+    if (format->no_neg_0)
+        flags |= Py_DTSF_NO_NEG_0;
+
+    if (type == '\0') {
+        /* Omitted type specifier.  Behaves in the same way as repr(x)
+           and str(x) if no precision is given, else like 'g', but with
+           at least one digit after the decimal point. */
+        flags |= Py_DTSF_ADD_DOT_0;
+        type = 'r';
+        default_precision = 0;
+    }
+
+    if (type == 'n')
+        /* 'n' is the same as 'g', except for the locale used to
+           format the result. We take care of that later. */
+        type = 'g';
+
+    val = PyFloat_AsDouble(value);
+    if (val == -1.0 && PyErr_Occurred())
+        goto done;
+
+    if (type == '%') {
+        type = 'f';
+        val *= 100;
+        add_pct = 1;
+    }
+
+    if (precision < 0)
+        precision = default_precision;
+    else if (type == 'r')
+        type = 'g';
+
+    /* Cast "type", because if we're in unicode we need to pass an
+       8-bit char. This is safe, because we've restricted what "type"
+       can be. */
+    buf = PyOS_double_to_string(val, (char)type, precision, flags,
+                                &float_type);
+    if (buf == NULL)
+        goto done;
+    n_digits = strlen(buf);
+
+    if (add_pct) {
+        /* We know that buf has a trailing zero (since we just called
+           strlen() on it), and we don't use that fact any more. So we
+           can just write over the trailing zero. */
+        buf[n_digits] = '%';
+        n_digits += 1;
+    }
+
+    if (format->sign != '+' && format->sign != ' '
+        && format->width == -1
+        && format->type != 'n'
+        && !format->thousands_separators)
+    {
+        /* Fast path */
+        result = _PyUnicodeWriter_WriteASCIIString(writer, buf, n_digits);
+        PyMem_Free(buf);
+        return result;
+    }
+
+    /* Since there is no unicode version of PyOS_double_to_string,
+       just use the 8 bit version and then convert to unicode. */
+    unicode_tmp = _PyUnicode_FromASCII(buf, n_digits);
+    PyMem_Free(buf);
+    if (unicode_tmp == NULL)
+        goto done;
+
+    /* Is a sign character present in the output?  If so, remember it
+       and skip it */
+    index = 0;
+    if (PyUnicode_READ_CHAR(unicode_tmp, index) == '-') {
+        sign_char = '-';
+        ++index;
+        --n_digits;
+    }
+
+    /* Determine if we have any "remainder" (after the digits, might include
+       decimal or exponent or both (or neither)) */
+    parse_number(unicode_tmp, index, index + n_digits, &n_remainder, &has_decimal);
+
+    /* Determine the grouping, separator, and decimal point, if any. */
+    if (get_locale_info(format->type == 'n' ? LT_CURRENT_LOCALE :
+                        format->thousands_separators,
+                        &locale) == -1)
+        goto done;
+
+    /* Calculate how much memory we'll need. */
+    n_total = calc_number_widths(&spec, 0, sign_char, index,
+                                 index + n_digits, n_remainder, has_decimal,
+                                 &locale, format, &maxchar);
+    if (n_total == -1) {
+        goto done;
+    }
+
+    /* Allocate the memory. */
+    if (_PyUnicodeWriter_Prepare(writer, n_total, maxchar) == -1)
+        goto done;
+
+    /* Populate the memory. */
+    result = fill_number(writer, &spec,
+                         unicode_tmp, index,
+                         NULL, 0, format->fill_char,
+                         &locale, 0);
+
+done:
+    Py_XDECREF(unicode_tmp);
+    free_locale_info(&locale);
+    return result;
+}
+
+/************************************************************************/
+/*********** complex formatting *****************************************/
+/************************************************************************/
+
+static int
+format_complex_internal(PyObject *value,
+                        const InternalFormatSpec *format,
+                        _PyUnicodeWriter *writer)
+{
+    double re;
+    double im;
+    char *re_buf = NULL;       /* buffer returned from PyOS_double_to_string */
+    char *im_buf = NULL;       /* buffer returned from PyOS_double_to_string */
+
+    InternalFormatSpec tmp_format = *format;
+    Py_ssize_t n_re_digits;
+    Py_ssize_t n_im_digits;
+    Py_ssize_t n_re_remainder;
+    Py_ssize_t n_im_remainder;
+    Py_ssize_t n_re_total;
+    Py_ssize_t n_im_total;
+    int re_has_decimal;
+    int im_has_decimal;
+    int precision, default_precision = 6;
+    Py_UCS4 type = format->type;
+    Py_ssize_t i_re;
+    Py_ssize_t i_im;
+    NumberFieldWidths re_spec;
+    NumberFieldWidths im_spec;
+    int flags = 0;
+    int result = -1;
+    Py_UCS4 maxchar = 127;
+    int rkind;
+    void *rdata;
+    Py_UCS4 re_sign_char = '\0';
+    Py_UCS4 im_sign_char = '\0';
+    int re_float_type; /* Used to see if we have a nan, inf, or regular float. */
+    int im_float_type;
+    int add_parens = 0;
+    int skip_re = 0;
+    Py_ssize_t lpad;
+    Py_ssize_t rpad;
+    Py_ssize_t total;
+    PyObject *re_unicode_tmp = NULL;
+    PyObject *im_unicode_tmp = NULL;
+
+    /* Locale settings, either from the actual locale or
+       from a hard-code pseudo-locale */
+    LocaleInfo locale = LocaleInfo_STATIC_INIT;
+
+    if (format->precision > INT_MAX) {
+        PyErr_SetString(PyExc_ValueError, "precision too big");
+        goto done;
+    }
+    precision = (int)format->precision;
+
+    /* Zero padding is not allowed. */
+    if (format->fill_char == '0') {
+        PyErr_SetString(PyExc_ValueError,
+                        "Zero padding is not allowed in complex format "
+                        "specifier");
+        goto done;
+    }
+
+    /* Neither is '=' alignment . */
+    if (format->align == '=') {
+        PyErr_SetString(PyExc_ValueError,
+                        "'=' alignment flag is not allowed in complex format "
+                        "specifier");
+        goto done;
+    }
+
+    re = PyComplex_RealAsDouble(value);
+    if (re == -1.0 && PyErr_Occurred())
+        goto done;
+    im = PyComplex_ImagAsDouble(value);
+    if (im == -1.0 && PyErr_Occurred())
+        goto done;
+
+    if (format->alternate)
+        flags |= Py_DTSF_ALT;
+    if (format->no_neg_0)
+        flags |= Py_DTSF_NO_NEG_0;
+
+    if (type == '\0') {
+        /* Omitted type specifier. Should be like str(self). */
+        type = 'r';
+        default_precision = 0;
+        if (re == 0.0 && copysign(1.0, re) == 1.0)
+            skip_re = 1;
+        else
+            add_parens = 1;
+    }
+
+    if (type == 'n')
+        /* 'n' is the same as 'g', except for the locale used to
+           format the result. We take care of that later. */
+        type = 'g';
+
+    if (precision < 0)
+        precision = default_precision;
+    else if (type == 'r')
+        type = 'g';
+
+    /* Cast "type", because if we're in unicode we need to pass an
+       8-bit char. This is safe, because we've restricted what "type"
+       can be. */
+    re_buf = PyOS_double_to_string(re, (char)type, precision, flags,
+                                   &re_float_type);
+    if (re_buf == NULL)
+        goto done;
+    im_buf = PyOS_double_to_string(im, (char)type, precision, flags,
+                                   &im_float_type);
+    if (im_buf == NULL)
+        goto done;
+
+    n_re_digits = strlen(re_buf);
+    n_im_digits = strlen(im_buf);
+
+    /* Since there is no unicode version of PyOS_double_to_string,
+       just use the 8 bit version and then convert to unicode. */
+    re_unicode_tmp = _PyUnicode_FromASCII(re_buf, n_re_digits);
+    if (re_unicode_tmp == NULL)
+        goto done;
+    i_re = 0;
+
+    im_unicode_tmp = _PyUnicode_FromASCII(im_buf, n_im_digits);
+    if (im_unicode_tmp == NULL)
+        goto done;
+    i_im = 0;
+
+    /* Is a sign character present in the output?  If so, remember it
+       and skip it */
+    if (PyUnicode_READ_CHAR(re_unicode_tmp, i_re) == '-') {
+        re_sign_char = '-';
+        ++i_re;
+        --n_re_digits;
+    }
+    if (PyUnicode_READ_CHAR(im_unicode_tmp, i_im) == '-') {
+        im_sign_char = '-';
+        ++i_im;
+        --n_im_digits;
+    }
+
+    /* Determine if we have any "remainder" (after the digits, might include
+       decimal or exponent or both (or neither)) */
+    parse_number(re_unicode_tmp, i_re, i_re + n_re_digits,
+                 &n_re_remainder, &re_has_decimal);
+    parse_number(im_unicode_tmp, i_im, i_im + n_im_digits,
+                 &n_im_remainder, &im_has_decimal);
+
+    /* Determine the grouping, separator, and decimal point, if any. */
+    if (get_locale_info(format->type == 'n' ? LT_CURRENT_LOCALE :
+                        format->thousands_separators,
+                        &locale) == -1)
+        goto done;
+
+    /* Turn off any padding. We'll do it later after we've composed
+       the numbers without padding. */
+    tmp_format.fill_char = '\0';
+    tmp_format.align = '<';
+    tmp_format.width = -1;
+
+    /* Calculate how much memory we'll need. */
+    n_re_total = calc_number_widths(&re_spec, 0, re_sign_char,
+                                    i_re, i_re + n_re_digits, n_re_remainder,
+                                    re_has_decimal, &locale, &tmp_format,
+                                    &maxchar);
+    if (n_re_total == -1) {
+        goto done;
+    }
+
+    /* Same formatting, but always include a sign, unless the real part is
+     * going to be omitted, in which case we use whatever sign convention was
+     * requested by the original format. */
+    if (!skip_re)
+        tmp_format.sign = '+';
+    n_im_total = calc_number_widths(&im_spec, 0, im_sign_char,
+                                    i_im, i_im + n_im_digits, n_im_remainder,
+                                    im_has_decimal, &locale, &tmp_format,
+                                    &maxchar);
+    if (n_im_total == -1) {
+        goto done;
+    }
+
+    if (skip_re)
+        n_re_total = 0;
+
+    /* Add 1 for the 'j', and optionally 2 for parens. */
+    calc_padding(n_re_total + n_im_total + 1 + add_parens * 2,
+                 format->width, format->align, &lpad, &rpad, &total);
+
+    if (lpad || rpad)
+        maxchar = Py_MAX(maxchar, format->fill_char);
+
+    if (_PyUnicodeWriter_Prepare(writer, total, maxchar) == -1)
+        goto done;
+    rkind = writer->kind;
+    rdata = writer->data;
+
+    /* Populate the memory. First, the padding. */
+    result = fill_padding(writer,
+                          n_re_total + n_im_total + 1 + add_parens * 2,
+                          format->fill_char, lpad, rpad);
+    if (result == -1)
+        goto done;
+
+    if (add_parens) {
+        PyUnicode_WRITE(rkind, rdata, writer->pos, '(');
+        writer->pos++;
+    }
+
+    if (!skip_re) {
+        result = fill_number(writer, &re_spec,
+                             re_unicode_tmp, i_re,
+                             NULL, 0,
+                             0,
+                             &locale, 0);
+        if (result == -1)
+            goto done;
+    }
+    result = fill_number(writer, &im_spec,
+                         im_unicode_tmp, i_im,
+                         NULL, 0,
+                         0,
+                         &locale, 0);
+    if (result == -1)
+        goto done;
+    PyUnicode_WRITE(rkind, rdata, writer->pos, 'j');
+    writer->pos++;
+
+    if (add_parens) {
+        PyUnicode_WRITE(rkind, rdata, writer->pos, ')');
+        writer->pos++;
+    }
+
+    writer->pos += rpad;
+
+done:
+    PyMem_Free(re_buf);
+    PyMem_Free(im_buf);
+    Py_XDECREF(re_unicode_tmp);
+    Py_XDECREF(im_unicode_tmp);
+    free_locale_info(&locale);
+    return result;
+}
+
+/************************************************************************/
+/*********** built in formatters ****************************************/
+/************************************************************************/
+static int
+format_obj(PyObject *obj, _PyUnicodeWriter *writer)
+{
+    PyObject *str;
+    int err;
+
+    str = PyObject_Str(obj);
+    if (str == NULL)
+        return -1;
+    err = _PyUnicodeWriter_WriteStr(writer, str);
+    Py_DECREF(str);
+    return err;
+}
+
+int
+_PyUnicode_FormatAdvancedWriter(_PyUnicodeWriter *writer,
+                                PyObject *obj,
+                                PyObject *format_spec,
+                                Py_ssize_t start, Py_ssize_t end)
+{
+    InternalFormatSpec format;
+
+    assert(PyUnicode_Check(obj));
+
+    /* check for the special case of zero length format spec, make
+       it equivalent to str(obj) */
+    if (start == end) {
+        if (PyUnicode_CheckExact(obj))
+            return _PyUnicodeWriter_WriteStr(writer, obj);
+        else
+            return format_obj(obj, writer);
+    }
+
+    /* parse the format_spec */
+    if (!parse_internal_render_format_spec(obj, format_spec, start, end,
+                                           &format, 's', '<'))
+        return -1;
+
+    /* type conversion? */
+    switch (format.type) {
+    case 's':
+        /* no type conversion needed, already a string.  do the formatting */
+        return format_string_internal(obj, &format, writer);
+    default:
+        /* unknown */
+        unknown_presentation_type(format.type, Py_TYPE(obj)->tp_name);
+        return -1;
+    }
+}
+
+int
+_PyLong_FormatAdvancedWriter(_PyUnicodeWriter *writer,
+                             PyObject *obj,
+                             PyObject *format_spec,
+                             Py_ssize_t start, Py_ssize_t end)
+{
+    PyObject *tmp = NULL;
+    InternalFormatSpec format;
+    int result = -1;
+
+    /* check for the special case of zero length format spec, make
+       it equivalent to str(obj) */
+    if (start == end) {
+        if (PyLong_CheckExact(obj))
+            return _PyLong_FormatWriter(writer, obj, 10, 0);
+        else
+            return format_obj(obj, writer);
+    }
+
+    /* parse the format_spec */
+    if (!parse_internal_render_format_spec(obj, format_spec, start, end,
+                                           &format, 'd', '>'))
+        goto done;
+
+    /* type conversion? */
+    switch (format.type) {
+    case 'b':
+    case 'c':
+    case 'd':
+    case 'o':
+    case 'x':
+    case 'X':
+    case 'n':
+        /* no type conversion needed, already an int.  do the formatting */
+        result = format_long_internal(obj, &format, writer);
+        break;
+
+    case 'e':
+    case 'E':
+    case 'f':
+    case 'F':
+    case 'g':
+    case 'G':
+    case '%':
+        /* convert to float */
+        tmp = PyNumber_Float(obj);
+        if (tmp == NULL)
+            goto done;
+        result = format_float_internal(tmp, &format, writer);
+        break;
+
+    default:
+        /* unknown */
+        unknown_presentation_type(format.type, Py_TYPE(obj)->tp_name);
+        goto done;
+    }
+
+done:
+    Py_XDECREF(tmp);
+    return result;
+}
+
+int
+_PyFloat_FormatAdvancedWriter(_PyUnicodeWriter *writer,
+                              PyObject *obj,
+                              PyObject *format_spec,
+                              Py_ssize_t start, Py_ssize_t end)
+{
+    InternalFormatSpec format;
+
+    /* check for the special case of zero length format spec, make
+       it equivalent to str(obj) */
+    if (start == end)
+        return format_obj(obj, writer);
+
+    /* parse the format_spec */
+    if (!parse_internal_render_format_spec(obj, format_spec, start, end,
+                                           &format, '\0', '>'))
+        return -1;
+
+    /* type conversion? */
+    switch (format.type) {
+    case '\0': /* No format code: like 'g', but with at least one decimal. */
+    case 'e':
+    case 'E':
+    case 'f':
+    case 'F':
+    case 'g':
+    case 'G':
+    case 'n':
+    case '%':
+        /* no conversion, already a float.  do the formatting */
+        return format_float_internal(obj, &format, writer);
+
+    default:
+        /* unknown */
+        unknown_presentation_type(format.type, Py_TYPE(obj)->tp_name);
+        return -1;
+    }
+}
+
+int
+_PyComplex_FormatAdvancedWriter(_PyUnicodeWriter *writer,
+                                PyObject *obj,
+                                PyObject *format_spec,
+                                Py_ssize_t start, Py_ssize_t end)
+{
+    InternalFormatSpec format;
+
+    /* check for the special case of zero length format spec, make
+       it equivalent to str(obj) */
+    if (start == end)
+        return format_obj(obj, writer);
+
+    /* parse the format_spec */
+    if (!parse_internal_render_format_spec(obj, format_spec, start, end,
+                                           &format, '\0', '>'))
+        return -1;
+
+    /* type conversion? */
+    switch (format.type) {
+    case '\0': /* No format code: like 'g', but with at least one decimal. */
+    case 'e':
+    case 'E':
+    case 'f':
+    case 'F':
+    case 'g':
+    case 'G':
+    case 'n':
+        /* no conversion, already a complex.  do the formatting */
+        return format_complex_internal(obj, &format, writer);
+
+    default:
+        /* unknown */
+        unknown_presentation_type(format.type, Py_TYPE(obj)->tp_name);
+        return -1;
+    }
+}