upb-temp/upb/lex/unicode.h

// Protocol Buffers - Google's data interchange format
// Copyright 2023 Google LLC.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google LLC nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef UPB_LEX_UNICODE_H_
#define UPB_LEX_UNICODE_H_

#include <stdint.h>

// Must be last.
#include "upb/port/def.inc"

#ifdef __cplusplus
extern "C" {
#endif

// Returns true iff a codepoint is the value for a high surrogate.
UPB_INLINE bool upb_Unicode_IsHigh(uint32_t cp) {
  return (cp >= 0xd800 && cp <= 0xdbff);
}

// Returns true iff a codepoint is the value for a low surrogate.
UPB_INLINE bool upb_Unicode_IsLow(uint32_t cp) {
  return (cp >= 0xdc00 && cp <= 0xdfff);
}

// Returns the high 16-bit surrogate value for a supplementary codepoint.
// Does not sanity-check the input.
UPB_INLINE uint16_t upb_Unicode_ToHigh(uint32_t cp) {
  return (cp >> 10) + 0xd7c0;
}

// Returns the low 16-bit surrogate value for a supplementary codepoint.
// Does not sanity-check the input.
UPB_INLINE uint16_t upb_Unicode_ToLow(uint32_t cp) {
  return (cp & 0x3ff) | 0xdc00;
}

// Returns the 32-bit value corresponding to a pair of 16-bit surrogates.
// Does not sanity-check the input.
UPB_INLINE uint32_t upb_Unicode_FromPair(uint32_t high, uint32_t low) {
  return ((high & 0x3ff) << 10) + (low & 0x3ff) + 0x10000;
}

// Outputs a codepoint as UTF8.
// Returns the number of bytes written (1-4 on success, 0 on error).
// Does not sanity-check the input. Specifically does not check for surrogates.
int upb_Unicode_ToUTF8(uint32_t cp, char* out);

#ifdef __cplusplus
} /* extern "C" */
#endif

#include "upb/port/undef.inc"

#endif /* UPB_LEX_UNICODE_H_ */