/* * Copyright (c) 2010, 2017 Craig A. Berry * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ /* vms_shorten_symbol * * This program provides shortening of long symbols (> 31 characters) using the * same mechanism as the OpenVMS C compiler. The basic procedure is to compute * an AUTODIN II checksum of the entire symbol, encode the checksum in base32, * and glue together a shortened symbol from the first 23 characters of the * original symbol plus the encoded checksum appended. The output format is * the same used in the name mangler database, stored by default in * [.CXX_REPOSITORY]CXX$DEMANGLER_DB. * * To obtain the same result as CC/NAMES=SHORTENED, run like so: * * $ mcr []vms_shorten_symbol "Please_forgive_this_absurdly_long_symbol_name" * PLEASE_FORGIVE_THIS_ABS1ARO4QU$Please_forgive_this_absurdly_long_symbol_name * * To obtain the same result as CC/NAMES=(SHORTENED,AS_IS), pass a non-zero * value as the second argument, like so: * * $ mcr []vms_shorten_symbol "Please_forgive_this_absurdly_long_symbol_name" 1 * Please_forgive_this_abs3rv8rnn$Please_forgive_this_absurdly_long_symbol_name */ #include #include #include #include #ifdef __VMS #define UINT32 unsigned int #else #include #define UINT32 uint32_t #endif extern UINT32 crc32(const char *input_string); extern int u32_to_base32(UINT32 input, char *output); extern int vms_shorten_symbol(const char *symbol, char *shortened, char as_is_flag); /* * This routine implements the AUTODIN II polynomial. */ UINT32 crc32(const char *input_string) { /* * CRC code and data based partly on FreeBSD implementation, which * notes: * * The crc32 functions and data was originally written by Spencer * Garrett and was cleaned from the PostgreSQL source * tree via the files contrib/ltree/crc32.[ch]. No license was * included, therefore it is assumed that this code is public * domain. Attribution still noted. * * (I think they mean "gleaned" not "cleaned".) */ static const UINT32 autodin_ii_table[256] = { 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d, }; UINT32 crc = ~0U; char *c; for (c = (char *)input_string; *c; ++c) crc = (crc >> 8) ^ autodin_ii_table[(crc ^ *c) & 0xff]; return ~crc; } /* * This is the RFC2938 variant of base32, not RFC3548, Crockford's, or * other newer variant. It produces an 8-byte encoded character string * (plus trailing null) from a 32-bit integer input. */ int u32_to_base32(UINT32 input, char *output) { static const char base32hex_table[32] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v' }; int i; /* * Grab lowest 5 bits and look up conversion in table. Lather, rinse, * repeat for a total of 7, 5-bit chunks to accommodate 32 bits of input. */ for (i = 0; i < 7; i++) { output[6 - i] = base32hex_table[input & 0x1f]; input >>= 5; /* position to look at next 5 */ } output[7] = '$'; /* It's DEC, so use '$' not '=' to pad. */ output[8] = '\0'; return 0; } /* * Take an input symbol name of arbitrary length and produce a symbol shortened * to 31 characters. The shortened symbol consists of the first 23 characters * of the original symbol plus the 8 characters of the encoded checksum. The * third argument is a boolean indicating whether to emulate the compiler's * /NAMES=AS_IS option. When false (the compiler's default), the shortened * symbol will be upper cased. When the original symbol is 31 characters or * fewer in length, no checksum will be appended and the original symbol is * returned verbatim (though upper cased if the as_is_flag is false). */ int vms_shorten_symbol(const char *input_symbol, char *shortened, char as_is_flag) { char b32str[9]; UINT32 crc; char *c, *symbol; int symlen; symlen = strlen(input_symbol); symbol = (char *)malloc(symlen + 1); if (symbol == NULL) return -1; strncpy(symbol, input_symbol, symlen); symbol[symlen] = '\0'; if (!as_is_flag) { for (c = symbol; *c; c++) *c = toupper(*c); } if (symlen <= 31) { strncpy(shortened, symbol, symlen); shortened[symlen] = '\0'; free(symbol); return 0; } /* * Compute the checksum on the whole symbol. */ crc = crc32(symbol); /* The compiler does not use the inverted checksum, so we invert it * back before encoding in base32. */ if (u32_to_base32(~crc, (char *)&b32str) == -1) { free(symbol); return -1; } if (!as_is_flag) { for (c = (char *)&b32str; *c; c++) *c = toupper(*c); } sprintf(shortened, "%.23s%.8s", symbol, b32str); shortened[31] = '\0'; free(symbol); return 0; } #ifdef TEST_MAIN int main(int argc, char **argv) { char short_symbol[32]; char as_is_flag = 0; if (argc < 2) { fprintf(stderr, "Usage: %s []\n", argv[0]); exit(EXIT_FAILURE); } if (argc > 2) as_is_flag = 1; if (vms_shorten_symbol(argv[1], (char *)&short_symbol, as_is_flag) == -1) { fprintf(stderr, "Symbol shortening failed\n"); exit(EXIT_FAILURE); } printf("%s%s\n", (char *)&short_symbol, argv[1]); } #endif