src/base/third_party/icu/icu_utf.h

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
******************************************************************************
*
*   Copyright (C) 1999-2015, International Business Machines
*   Corporation and others.  All Rights Reserved.
*
******************************************************************************
*/

#ifndef BASE_THIRD_PARTY_ICU_ICU_UTF_H_
#define BASE_THIRD_PARTY_ICU_ICU_UTF_H_

#include <stdint.h>

namespace base_icu {

// source/common/unicode/umachine.h

/** The ICU boolean type @stable ICU 2.0 */
typedef int8_t UBool;

/**
 * Define UChar32 as a type for single Unicode code points.
 * UChar32 is a signed 32-bit integer (same as int32_t).
 *
 * The Unicode code point range is 0..0x10ffff.
 * All other values (negative or >=0x110000) are illegal as Unicode code points.
 * They may be used as sentinel values to indicate "done", "error"
 * or similar non-code point conditions.
 *
 * Before ICU 2.4 (Jitterbug 2146), UChar32 was defined
 * to be wchar_t if that is 32 bits wide (wchar_t may be signed or unsigned)
 * or else to be uint32_t.
 * That is, the definition of UChar32 was platform-dependent.
 *
 * @see U_SENTINEL
 * @stable ICU 2.4
 */
typedef int32_t UChar32;

/**
 * This value is intended for sentinel values for APIs that
 * (take or) return single code points (UChar32).
 * It is outside of the Unicode code point range 0..0x10ffff.
 *
 * For example, a "done" or "error" value in a new API
 * could be indicated with U_SENTINEL.
 *
 * ICU APIs designed before ICU 2.4 usually define service-specific "done"
 * values, mostly 0xffff.
 * Those may need to be distinguished from
 * actual U+ffff text contents by calling functions like
 * CharacterIterator::hasNext() or UnicodeString::length().
 *
 * @return -1
 * @see UChar32
 * @stable ICU 2.4
 */
#define CBU_SENTINEL (-1)

// source/common/unicode/utf.h

/**
 * Is this code point a Unicode noncharacter?
 * @param c 32-bit code point
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU_IS_UNICODE_NONCHAR(c)                                \
  ((c) >= 0xfdd0 && ((c) <= 0xfdef || ((c)&0xfffe) == 0xfffe) && \
   (c) <= 0x10ffff)

/**
 * Is c a Unicode code point value (0..U+10ffff)
 * that can be assigned a character?
 *
 * Code points that are not characters include:
 * - single surrogate code points (U+d800..U+dfff, 2048 code points)
 * - the last two code points on each plane (U+__fffe and U+__ffff, 34 code
 * points) - U+fdd0..U+fdef (new with Unicode 3.1, 32 code points) - the highest
 * Unicode code point value is U+10ffff
 *
 * This means that all code points below U+d800 are character code points,
 * and that boundary is tested first for performance.
 *
 * @param c 32-bit code point
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU_IS_UNICODE_CHAR(c) \
  ((uint32_t)(c) < 0xd800 ||   \
   (0xdfff < (c) && (c) <= 0x10ffff && !CBU_IS_UNICODE_NONCHAR(c)))

/**
 * Is this code point a surrogate (U+d800..U+dfff)?
 * @param c 32-bit code point
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU_IS_SURROGATE(c) (((c)&0xfffff800) == 0xd800)

/**
 * Assuming c is a surrogate code point (U_IS_SURROGATE(c)),
 * is it a lead surrogate?
 * @param c 32-bit code point
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU_IS_SURROGATE_LEAD(c) (((c)&0x400) == 0)

// source/common/unicode/utf8.h

/**
 * Internal bit vector for 3-byte UTF-8 validity check, for use in
 * U8_IS_VALID_LEAD3_AND_T1. Each bit indicates whether one lead byte + first
 * trail byte pair starts a valid sequence. Lead byte E0..EF bits 3..0 are used
 * as byte index, first trail byte bits 7..5 are used as bit index into that
 * byte.
 * @see U8_IS_VALID_LEAD3_AND_T1
 * @internal
 */
#define CBU8_LEAD3_T1_BITS \
  "\x20\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x10\x30\x30"

/**
 * Internal 3-byte UTF-8 validity check.
 * Non-zero if lead byte E0..EF and first trail byte 00..FF start a valid
 * sequence.
 * @internal
 */
#define CBU8_IS_VALID_LEAD3_AND_T1(lead, t1) \
  (CBU8_LEAD3_T1_BITS[(lead)&0xf] & (1 << ((uint8_t)(t1) >> 5)))

/**
 * Internal bit vector for 4-byte UTF-8 validity check, for use in
 * U8_IS_VALID_LEAD4_AND_T1. Each bit indicates whether one lead byte + first
 * trail byte pair starts a valid sequence. First trail byte bits 7..4 are used
 * as byte index, lead byte F0..F4 bits 2..0 are used as bit index into that
 * byte.
 * @see U8_IS_VALID_LEAD4_AND_T1
 * @internal
 */
#define CBU8_LEAD4_T1_BITS \
  "\x00\x00\x00\x00\x00\x00\x00\x00\x1E\x0F\x0F\x0F\x00\x00\x00\x00"

/**
 * Internal 4-byte UTF-8 validity check.
 * Non-zero if lead byte F0..F4 and first trail byte 00..FF start a valid
 * sequence.
 * @internal
 */
#define CBU8_IS_VALID_LEAD4_AND_T1(lead, t1) \
  (CBU8_LEAD4_T1_BITS[(uint8_t)(t1) >> 4] & (1 << ((lead)&7)))

/**
 * Function for handling "next code point" with error-checking.
 *
 * This is internal since it is not meant to be called directly by external clie
nts;
 * however it is U_STABLE (not U_INTERNAL) since it is called by public macros i
n this
 * file and thus must remain stable, and should not be hidden when other interna
l
 * functions are hidden (otherwise public macros would fail to compile).
 * @internal
 */
UChar32 utf8_nextCharSafeBody(const uint8_t* s,
                              int32_t* pi,
                              int32_t length,
                              ::base_icu::UChar32 c,
                              ::base_icu::UBool strict);

/**
 * Does this code unit (byte) encode a code point by itself (US-ASCII 0..0x7f)?
 * @param c 8-bit code unit (byte)
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU8_IS_SINGLE(c) (((c)&0x80) == 0)

/**
 * Is this code unit (byte) a UTF-8 lead byte? (0xC2..0xF4)
 * @param c 8-bit code unit (byte)
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU8_IS_LEAD(c) ((uint8_t)((c)-0xc2) <= 0x32)

/**
 * Is this code unit (byte) a UTF-8 trail byte? (0x80..0xBF)
 * @param c 8-bit code unit (byte)
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU8_IS_TRAIL(c) ((int8_t)(c) < -0x40)

/**
 * How many code units (bytes) are used for the UTF-8 encoding
 * of this Unicode code point?
 * @param c 32-bit code point
 * @return 1..4, or 0 if c is a surrogate or not a Unicode code point
 * @stable ICU 2.4
 */
#define CBU8_LENGTH(c)                                                      \
  ((uint32_t)(c) <= 0x7f                                                    \
       ? 1                                                                  \
       : ((uint32_t)(c) <= 0x7ff                                            \
              ? 2                                                           \
              : ((uint32_t)(c) <= 0xd7ff                                    \
                     ? 3                                                    \
                     : ((uint32_t)(c) <= 0xdfff || (uint32_t)(c) > 0x10ffff \
                            ? 0                                             \
                            : ((uint32_t)(c) <= 0xffff ? 3 : 4)))))

/**
 * The maximum number of UTF-8 code units (bytes) per Unicode code point
 * (U+0000..U+10ffff).
 * @return 4
 * @stable ICU 2.4
 */
#define CBU8_MAX_LENGTH 4

/**
 * Get a code point from a string at a code point boundary offset,
 * and advance the offset to the next code point boundary.
 * (Post-incrementing forward iteration.)
 * "Safe" macro, checks for illegal sequences and for string boundaries.
 *
 * The length can be negative for a NUL-terminated string.
 *
 * The offset may point to the lead byte of a multi-byte sequence,
 * in which case the macro will read the whole sequence.
 * If the offset points to a trail byte or an illegal UTF-8 sequence, then
 * c is set to a negative value.
 *
 * @param s const uint8_t * string
 * @param i int32_t string offset, must be i<length
 * @param length int32_t string length
 * @param c output UChar32 variable, set to <0 in case of an error
 * @see U8_NEXT_UNSAFE
 * @stable ICU 2.4
 */
#define CBU8_NEXT(s, i, length, c)                                       \
  {                                                                      \
    (c) = (uint8_t)(s)[(i)++];                                           \
    if (!CBU8_IS_SINGLE(c)) {                                            \
      uint8_t __t1, __t2;                                                \
      if (/* handle U+0800..U+FFFF inline */                             \
          (0xe0 <= (c) && (c) < 0xf0) &&                                 \
          (((i) + 1) < (length) || (length) < 0) &&                      \
          CBU8_IS_VALID_LEAD3_AND_T1((c), __t1 = (s)[i]) &&              \
          (__t2 = (s)[(i) + 1] - 0x80) <= 0x3f) {                        \
        (c) = (((c)&0xf) << 12) | ((__t1 & 0x3f) << 6) | __t2;           \
        (i) += 2;                                                        \
      } else if (/* handle U+0080..U+07FF inline */                      \
                 ((c) < 0xe0 && (c) >= 0xc2) && ((i) != (length)) &&     \
                 (__t1 = (s)[i] - 0x80) <= 0x3f) {                       \
        (c) = (((c)&0x1f) << 6) | __t1;                                  \
        ++(i);                                                           \
      } else {                                                           \
        /* function call for "complicated" and error cases */            \
        (c) = ::base_icu::utf8_nextCharSafeBody((const uint8_t*)s, &(i), \
                                                (length), c, -1);        \
      }                                                                  \
    }                                                                    \
  }

/**
 * Append a code point to a string, overwriting 1 to 4 bytes.
 * The offset points to the current end of the string contents
 * and is advanced (post-increment).
 * "Unsafe" macro, assumes a valid code point and sufficient space in the
 * string. Otherwise, the result is undefined.
 *
 * @param s const uint8_t * string buffer
 * @param i string offset
 * @param c code point to append
 * @see U8_APPEND
 * @stable ICU 2.4
 */
#define CBU8_APPEND_UNSAFE(s, i, c)                            \
  {                                                            \
    if ((uint32_t)(c) <= 0x7f) {                               \
      (s)[(i)++] = (uint8_t)(c);                               \
    } else {                                                   \
      if ((uint32_t)(c) <= 0x7ff) {                            \
        (s)[(i)++] = (uint8_t)(((c) >> 6) | 0xc0);             \
      } else {                                                 \
        if ((uint32_t)(c) <= 0xffff) {                         \
          (s)[(i)++] = (uint8_t)(((c) >> 12) | 0xe0);          \
        } else {                                               \
          (s)[(i)++] = (uint8_t)(((c) >> 18) | 0xf0);          \
          (s)[(i)++] = (uint8_t)((((c) >> 12) & 0x3f) | 0x80); \
        }                                                      \
        (s)[(i)++] = (uint8_t)((((c) >> 6) & 0x3f) | 0x80);    \
      }                                                        \
      (s)[(i)++] = (uint8_t)(((c)&0x3f) | 0x80);               \
    }                                                          \
  }

// source/common/unicode/utf16.h

/**
 * Does this code unit alone encode a code point (BMP, not a surrogate)?
 * @param c 16-bit code unit
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU16_IS_SINGLE(c) !CBU_IS_SURROGATE(c)

/**
 * Is this code unit a lead surrogate (U+d800..U+dbff)?
 * @param c 16-bit code unit
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU16_IS_LEAD(c) (((c)&0xfffffc00) == 0xd800)

/**
 * Is this code unit a trail surrogate (U+dc00..U+dfff)?
 * @param c 16-bit code unit
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU16_IS_TRAIL(c) (((c)&0xfffffc00) == 0xdc00)

/**
 * Is this code unit a surrogate (U+d800..U+dfff)?
 * @param c 16-bit code unit
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU16_IS_SURROGATE(c) CBU_IS_SURROGATE(c)

/**
 * Assuming c is a surrogate code point (U16_IS_SURROGATE(c)),
 * is it a lead surrogate?
 * @param c 16-bit code unit
 * @return TRUE or FALSE
 * @stable ICU 2.4
 */
#define CBU16_IS_SURROGATE_LEAD(c) (((c)&0x400) == 0)

/**
 * Helper constant for U16_GET_SUPPLEMENTARY.
 * @internal
 */
#define CBU16_SURROGATE_OFFSET ((0xd800 << 10UL) + 0xdc00 - 0x10000)

/**
 * Get a supplementary code point value (U+10000..U+10ffff)
 * from its lead and trail surrogates.
 * The result is undefined if the input values are not
 * lead and trail surrogates.
 *
 * @param lead lead surrogate (U+d800..U+dbff)
 * @param trail trail surrogate (U+dc00..U+dfff)
 * @return supplementary code point (U+10000..U+10ffff)
 * @stable ICU 2.4
 */
#define CBU16_GET_SUPPLEMENTARY(lead, trail) \
  (((::base_icu::UChar32)(lead) << 10UL) +   \
   (::base_icu::UChar32)(trail)-CBU16_SURROGATE_OFFSET)

/**
 * Get the lead surrogate (0xd800..0xdbff) for a
 * supplementary code point (0x10000..0x10ffff).
 * @param supplementary 32-bit code point (U+10000..U+10ffff)
 * @return lead surrogate (U+d800..U+dbff) for supplementary
 * @stable ICU 2.4
 */
#define CBU16_LEAD(supplementary) \
  (::base_icu::UChar)(((supplementary) >> 10) + 0xd7c0)

/**
 * Get the trail surrogate (0xdc00..0xdfff) for a
 * supplementary code point (0x10000..0x10ffff).
 * @param supplementary 32-bit code point (U+10000..U+10ffff)
 * @return trail surrogate (U+dc00..U+dfff) for supplementary
 * @stable ICU 2.4
 */
#define CBU16_TRAIL(supplementary) \
  (::base_icu::UChar)(((supplementary)&0x3ff) | 0xdc00)

/**
 * How many 16-bit code units are used to encode this Unicode code point? (1 or
 * 2) The result is not defined if c is not a Unicode code point
 * (U+0000..U+10ffff).
 * @param c 32-bit code point
 * @return 1 or 2
 * @stable ICU 2.4
 */
#define CBU16_LENGTH(c) ((uint32_t)(c) <= 0xffff ? 1 : 2)

/**
 * The maximum number of 16-bit code units per Unicode code point
 * (U+0000..U+10ffff).
 * @return 2
 * @stable ICU 2.4
 */
#define CBU16_MAX_LENGTH 2

/**
 * Get a code point from a string at a code point boundary offset,
 * and advance the offset to the next code point boundary.
 * (Post-incrementing forward iteration.)
 * "Safe" macro, handles unpaired surrogates and checks for string boundaries.
 *
 * The length can be negative for a NUL-terminated string.
 *
 * The offset may point to the lead surrogate unit
 * for a supplementary code point, in which case the macro will read
 * the following trail surrogate as well.
 * If the offset points to a trail surrogate or
 * to a single, unpaired lead surrogate, then c is set to that unpaired
 * surrogate.
 *
 * @param s const UChar * string
 * @param i string offset, must be i<length
 * @param length string length
 * @param c output UChar32 variable
 * @see U16_NEXT_UNSAFE
 * @stable ICU 2.4
 */
#define CBU16_NEXT(s, i, length, c)                             \
  {                                                             \
    (c) = (s)[(i)++];                                           \
    if (CBU16_IS_LEAD(c)) {                                     \
      uint16_t __c2;                                            \
      if ((i) != (length) && CBU16_IS_TRAIL(__c2 = (s)[(i)])) { \
        ++(i);                                                  \
        (c) = CBU16_GET_SUPPLEMENTARY((c), __c2);               \
      }                                                         \
    }                                                           \
  }

/**
 * Append a code point to a string, overwriting 1 or 2 code units.
 * The offset points to the current end of the string contents
 * and is advanced (post-increment).
 * "Unsafe" macro, assumes a valid code point and sufficient space in the
 * string. Otherwise, the result is undefined.
 *
 * @param s const UChar * string buffer
 * @param i string offset
 * @param c code point to append
 * @see U16_APPEND
 * @stable ICU 2.4
 */
#define CBU16_APPEND_UNSAFE(s, i, c)                 \
  {                                                  \
    if ((uint32_t)(c) <= 0xffff) {                   \
      (s)[(i)++] = (uint16_t)(c);                    \
    } else {                                         \
      (s)[(i)++] = (uint16_t)(((c) >> 10) + 0xd7c0); \
      (s)[(i)++] = (uint16_t)(((c)&0x3ff) | 0xdc00); \
    }                                                \
  }

}  // namespace base_icu

#endif  // BASE_THIRD_PARTY_ICU_ICU_UTF_H_