1 /* 2 * 3 * Copyright 2015 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 /* generates constant table for metadata.cc */ 20 21 #include <stdio.h> 22 #include <string.h> 23 24 static unsigned char legal_bits[256 / 8]; 25 legal(int x)26static void legal(int x) { 27 int byte = x / 8; 28 int bit = x % 8; 29 /* NB: the following integer arithmetic operation needs to be in its 30 * expanded form due to the "integral promotion" performed (see section 31 * 3.2.1.1 of the C89 draft standard). A cast to the smaller container type 32 * is then required to avoid the compiler warning */ 33 legal_bits[byte] = 34 (unsigned char)((legal_bits[byte] | (unsigned char)(1 << bit))); 35 } 36 dump(void)37static void dump(void) { 38 int i; 39 40 printf("static const uint8_t legal_header_bits[256/8] = "); 41 for (i = 0; i < 256 / 8; i++) 42 printf("%c 0x%02x", i ? ',' : '{', legal_bits[i]); 43 printf(" };\n"); 44 } 45 clear(void)46static void clear(void) { memset(legal_bits, 0, sizeof(legal_bits)); } 47 main(void)48int main(void) { 49 int i; 50 51 clear(); 52 for (i = 'a'; i <= 'z'; i++) legal(i); 53 for (i = '0'; i <= '9'; i++) legal(i); 54 legal('-'); 55 legal('_'); 56 legal('.'); 57 dump(); 58 59 clear(); 60 for (i = 32; i <= 126; i++) { 61 legal(i); 62 } 63 dump(); 64 65 return 0; 66 } 67