// Protocol Buffers - Google's data interchange format // Copyright 2023 Google LLC. All rights reserved. // // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file or at // https://developers.google.com/open-source/licenses/bsd /* * Internal implementation details of the decoder that are shared between * decode.c and decode_fast.c. */ #ifndef UPB_WIRE_INTERNAL_DECODER_H_ #define UPB_WIRE_INTERNAL_DECODER_H_ #include #include "upb/mem/internal/arena.h" #include "upb/message/internal/message.h" #include "upb/wire/decode.h" #include "upb/wire/eps_copy_input_stream.h" #include "utf8_range.h" // Must be last. #include "upb/port/def.inc" #define DECODE_NOGROUP (uint32_t)-1 typedef struct upb_Decoder { upb_EpsCopyInputStream input; const upb_ExtensionRegistry* extreg; upb_Message* original_msg; // Pointer to preserve data to int depth; // Tracks recursion depth to bound stack usage. uint32_t end_group; // field number of END_GROUP tag, else DECODE_NOGROUP. uint16_t options; bool missing_required; union { upb_Arena arena; void* foo[UPB_ARENA_SIZE_HACK]; }; upb_DecodeStatus status; jmp_buf err; #ifndef NDEBUG const char* debug_tagstart; const char* debug_valstart; #endif } 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* _upb_FastDecoder_ErrorJmp(upb_Decoder* d, int status); extern const uint8_t upb_utf8_offsets[]; UPB_INLINE bool _upb_Decoder_VerifyUtf8Inline(const char* ptr, int len) { return utf8_range_IsValid(ptr, len); } const char* _upb_Decoder_CheckRequired(upb_Decoder* d, const char* ptr, const upb_Message* msg, const upb_MiniTable* m); /* 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) { return ((intptr_t)tablep << 8) | tablep->UPB_PRIVATE(table_mask); } UPB_INLINE const upb_MiniTable* decode_totablep(intptr_t table) { return (const upb_MiniTable*)(table >> 8); } const char* _upb_Decoder_IsDoneFallback(upb_EpsCopyInputStream* e, const char* ptr, int overrun); UPB_INLINE bool _upb_Decoder_IsDone(upb_Decoder* d, const char** ptr) { return upb_EpsCopyInputStream_IsDoneWithCallback( &d->input, ptr, &_upb_Decoder_IsDoneFallback); } UPB_INLINE const char* _upb_Decoder_BufferFlipCallback( upb_EpsCopyInputStream* e, const char* old_end, const char* new_start) { upb_Decoder* d = (upb_Decoder*)e; if (!old_end) _upb_FastDecoder_ErrorJmp(d, kUpb_DecodeStatus_Malformed); return new_start; } #if UPB_FASTTABLE UPB_INLINE const char* _upb_FastDecoder_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->UPB_PRIVATE(fasttable)[idx].field_data ^ tag; UPB_MUSTTAIL return table_p->UPB_PRIVATE(fasttable)[idx].field_parser( d, ptr, msg, table, hasbits, data); } #endif UPB_INLINE uint32_t _upb_FastDecoder_LoadTag(const char* ptr) { uint16_t tag; memcpy(&tag, ptr, 2); return tag; } #include "upb/port/undef.inc" #endif /* UPB_WIRE_INTERNAL_DECODER_H_ */