chromium/third_party/grpc/src/third_party/upb/upb/internal/decode.h

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 * Copyright (c) 2009-2021, Google LLC
 * All rights reserved.
 *
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 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
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 *       notice, this list of conditions and the following disclaimer in the
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 *       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
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/*
 * Internal implementation details of the decoder that are shared between
 * decode.c and decode_fast.c.
 */

#ifndef UPB_INTERNAL_DECODE_H_
#define UPB_INTERNAL_DECODE_H_

#include <setjmp.h>

#include "upb/decode.h"
#include "upb/internal/upb.h"
#include "upb/msg_internal.h"
#include "third_party/utf8_range/utf8_range.h"

/* Must be last. */
#include "upb/port_def.inc"

#define DECODE_NOGROUP …

upb_Decoder;

/* Error function that will abort decoding with longjmp(). We can't declare this
 * UPB_NORETURN, even though it is appropriate, because if we do then compilers
 * will "helpfully" refuse to tailcall to it
 * (see: https://stackoverflow.com/a/55657013), which will defeat a major goal
 * of our optimizations. That is also why we must declare it in a separate file,
 * otherwise the compiler will see that it calls longjmp() and deduce that it is
 * noreturn. */
const char* fastdecode_err(upb_Decoder* d, int status);

extern const uint8_t upb_utf8_offsets[];

UPB_INLINE
bool decode_verifyutf8_inl(const char* ptr, int len) { … }

const char* decode_checkrequired(upb_Decoder* d, const char* ptr,
                                 const upb_Message* msg,
                                 const upb_MiniTable* l);

/* x86-64 pointers always have the high 16 bits matching. So we can shift
 * left 8 and right 8 without loss of information. */
UPB_INLINE intptr_t decode_totable(const upb_MiniTable* tablep) { … }

UPB_INLINE const upb_MiniTable* decode_totablep(intptr_t table) { … }

UPB_INLINE
const char* decode_isdonefallback_inl(upb_Decoder* d, const char* ptr,
                                      int overrun, int* status) { … }

const char* decode_isdonefallback(upb_Decoder* d, const char* ptr, int overrun);

UPB_INLINE
bool decode_isdone(upb_Decoder* d, const char** ptr) { … }

#if UPB_FASTTABLE
UPB_INLINE
const char* fastdecode_tagdispatch(upb_Decoder* d, const char* ptr,
                                   upb_Message* msg, intptr_t table,
                                   uint64_t hasbits, uint64_t tag) {
  const upb_MiniTable* table_p = decode_totablep(table);
  uint8_t mask = table;
  uint64_t data;
  size_t idx = tag & mask;
  UPB_ASSUME((idx & 7) == 0);
  idx >>= 3;
  data = table_p->fasttable[idx].field_data ^ tag;
  UPB_MUSTTAIL return table_p->fasttable[idx].field_parser(d, ptr, msg, table,
                                                           hasbits, data);
}
#endif

UPB_INLINE uint32_t fastdecode_loadtag(const char* ptr) { … }

UPB_INLINE void decode_checklimit(upb_Decoder* d) { … }

UPB_INLINE int decode_pushlimit(upb_Decoder* d, const char* ptr, int size) { … }

UPB_INLINE void decode_poplimit(upb_Decoder* d, const char* ptr,
                                int saved_delta) { … }

#include "upb/port_undef.inc"

#endif /* UPB_INTERNAL_DECODE_H_ */