1 // Copyright 2020 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 15 // Configuration macros for the tokenizer module. 16 #pragma once 17 18 #include <assert.h> 19 20 // For a tokenized string that has arguments, the types of the arguments are 21 // encoded in either a 4-byte (uint32_t) or a 8-byte (uint64_t) value. The 4 or 22 // 6 least-significant bits, respectively, store the number of arguments, while 23 // the remaining bits encode the argument types. Argument types are encoded 24 // two-bits per argument, in little-endian order. Up to 14 arguments in 4 bytes 25 // or 29 arguments in 8 bytes are supported. 26 #ifndef PW_TOKENIZER_CFG_ARG_TYPES_SIZE_BYTES 27 #define PW_TOKENIZER_CFG_ARG_TYPES_SIZE_BYTES 4 28 #endif // PW_TOKENIZER_CFG_ARG_TYPES_SIZE_BYTES 29 30 static_assert(PW_TOKENIZER_CFG_ARG_TYPES_SIZE_BYTES == 4 || 31 PW_TOKENIZER_CFG_ARG_TYPES_SIZE_BYTES == 8, 32 "PW_TOKENIZER_CFG_ARG_TYPES_SIZE_BYTES must be 4 or 8"); 33 34 // Maximum number of characters to hash in C. In C code, strings shorter than 35 // this length are treated as if they were zero-padded up to the length. Strings 36 // that are the same length and share a common prefix longer than this value 37 // hash to the same value. Increasing PW_TOKENIZER_CFG_C_HASH_LENGTH increases 38 // the compilation time for C due to the complexity of the hashing macros. 39 // 40 // PW_TOKENIZER_CFG_C_HASH_LENGTH has no effect on C++ code. In C++, hashing is 41 // done with a constexpr function instead of a macro. There are no string length 42 // limitations and compilation times are unaffected by this macro. 43 // 44 // Only hash lengths for which there is a corresponding macro header 45 // (pw_tokenizer/internal/mash_macro_#.h) are supported. Additional macros may 46 // be generated with the generate_hash_macro.py function. New macro headers must 47 // then be added to pw_tokenizer/internal/hash.h. 48 // 49 // This MUST match the value of DEFAULT_C_HASH_LENGTH in 50 // pw_tokenizer/py/pw_tokenizer/tokens.py. 51 #ifndef PW_TOKENIZER_CFG_C_HASH_LENGTH 52 #define PW_TOKENIZER_CFG_C_HASH_LENGTH 128 53 #endif // PW_TOKENIZER_CFG_C_HASH_LENGTH 54 55 // The size of the stack-allocated argument encoding buffer to use. This only 56 // affects tokenization macros that stack-allocate the encoding buffer 57 // (PW_TOKENIZE_TO_CALLBACK and PW_TOKENIZE_TO_GLOBAL_HANDLER). A buffer of this 58 // size is allocated and used for the 4-byte token and for encoding all 59 // arguments. It must be at least large enough for the token (4 bytes). 60 // 61 // This buffer does not need to be large to accommodate a good number of 62 // tokenized string arguments. Integer arguments are usually encoded smaller 63 // than their native size (e.g. 1 or 2 bytes for smaller numbers). All floating 64 // point types are encoded as four bytes. Null-terminated strings are encoded 65 // 1:1 in size. 66 #ifndef PW_TOKENIZER_CFG_ENCODING_BUFFER_SIZE_BYTES 67 #define PW_TOKENIZER_CFG_ENCODING_BUFFER_SIZE_BYTES 52 68 #endif // PW_TOKENIZER_CFG_ENCODING_BUFFER_SIZE_BYTES 69