The Tor Browser / file comparison
comparison: media/libpng/arm/linux.c
media/libpng/arm/linux.c
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
equal
deleted
inserted
replaced
| -1:000000000000 | 0:4d5f4162df25 |
|---|---|
| 1 /* contrib/arm-neon/linux.c | |
| 2 * | |
| 3 * Copyright (c) 2014 Glenn Randers-Pehrson | |
| 4 * Written by John Bowler, 2014. | |
| 5 * Last changed in libpng 1.6.10 [March 6, 2014] | |
| 6 * | |
| 7 * This code is released under the libpng license. | |
| 8 * For conditions of distribution and use, see the disclaimer | |
| 9 * and license in png.h | |
| 10 * | |
| 11 * SEE contrib/arm-neon/README before reporting bugs | |
| 12 * | |
| 13 * STATUS: SUPPORTED | |
| 14 * BUG REPORTS: png-mng-implement@sourceforge.net | |
| 15 * | |
| 16 * png_have_neon implemented for Linux by reading the widely available | |
| 17 * pseudo-file /proc/cpuinfo. | |
| 18 * | |
| 19 * This code is strict ANSI-C and is probably moderately portable, it does | |
| 20 * however use <stdio.h> and assumes that /proc/cpuinfo is never localized. | |
| 21 */ | |
| 22 #include <stdio.h> | |
| 23 | |
| 24 static int | |
| 25 png_have_neon(png_structp png_ptr) | |
| 26 { | |
| 27 FILE *f = fopen("/proc/cpuinfo", "rb"); | |
| 28 | |
| 29 if (f != NULL) | |
| 30 { | |
| 31 /* This is a simple state machine which reads the input byte-by-byte until | |
| 32 * it gets a match on the 'neon' feature or reaches the end of the stream. | |
| 33 */ | |
| 34 static const char ch_feature[] = { 70, 69, 65, 84, 85, 82, 69, 83 }; | |
| 35 static const char ch_neon[] = { 78, 69, 79, 78 }; | |
| 36 | |
| 37 enum | |
| 38 { | |
| 39 StartLine, Feature, Colon, StartTag, Neon, HaveNeon, SkipTag, SkipLine | |
| 40 } state; | |
| 41 int counter; | |
| 42 | |
| 43 for (state=StartLine, counter=0;;) | |
| 44 { | |
| 45 int ch = fgetc(f); | |
| 46 | |
| 47 if (ch == EOF) | |
| 48 { | |
| 49 /* EOF means error or end-of-file, return false; neon at EOF is | |
| 50 * assumed to be a mistake. | |
| 51 */ | |
| 52 fclose(f); | |
| 53 return 0; | |
| 54 } | |
| 55 | |
| 56 switch (state) | |
| 57 { | |
| 58 case StartLine: | |
| 59 /* Match spaces at the start of line */ | |
| 60 if (ch <= 32) /* skip control characters and space */ | |
| 61 break; | |
| 62 | |
| 63 counter=0; | |
| 64 state = Feature; | |
| 65 /* FALL THROUGH */ | |
| 66 | |
| 67 case Feature: | |
| 68 /* Match 'FEATURE', ASCII case insensitive. */ | |
| 69 if ((ch & ~0x20) == ch_feature[counter]) | |
| 70 { | |
| 71 if (++counter == (sizeof ch_feature)) | |
| 72 state = Colon; | |
| 73 break; | |
| 74 } | |
| 75 | |
| 76 /* did not match 'feature' */ | |
| 77 state = SkipLine; | |
| 78 /* FALL THROUGH */ | |
| 79 | |
| 80 case SkipLine: | |
| 81 skipLine: | |
| 82 /* Skip everything until we see linefeed or carriage return */ | |
| 83 if (ch != 10 && ch != 13) | |
| 84 break; | |
| 85 | |
| 86 state = StartLine; | |
| 87 break; | |
| 88 | |
| 89 case Colon: | |
| 90 /* Match any number of space or tab followed by ':' */ | |
| 91 if (ch == 32 || ch == 9) | |
| 92 break; | |
| 93 | |
| 94 if (ch == 58) /* i.e. ':' */ | |
| 95 { | |
| 96 state = StartTag; | |
| 97 break; | |
| 98 } | |
| 99 | |
| 100 /* Either a bad line format or a 'feature' prefix followed by | |
| 101 * other characters. | |
| 102 */ | |
| 103 state = SkipLine; | |
| 104 goto skipLine; | |
| 105 | |
| 106 case StartTag: | |
| 107 /* Skip space characters before a tag */ | |
| 108 if (ch == 32 || ch == 9) | |
| 109 break; | |
| 110 | |
| 111 state = Neon; | |
| 112 counter = 0; | |
| 113 /* FALL THROUGH */ | |
| 114 | |
| 115 case Neon: | |
| 116 /* Look for 'neon' tag */ | |
| 117 if ((ch & ~0x20) == ch_neon[counter]) | |
| 118 { | |
| 119 if (++counter == (sizeof ch_neon)) | |
| 120 state = HaveNeon; | |
| 121 break; | |
| 122 } | |
| 123 | |
| 124 state = SkipTag; | |
| 125 /* FALL THROUGH */ | |
| 126 | |
| 127 case SkipTag: | |
| 128 /* Skip non-space characters */ | |
| 129 if (ch == 10 || ch == 13) | |
| 130 state = StartLine; | |
| 131 | |
| 132 else if (ch == 32 || ch == 9) | |
| 133 state = StartTag; | |
| 134 break; | |
| 135 | |
| 136 case HaveNeon: | |
| 137 /* Have seen a 'neon' prefix, but there must be a space or new | |
| 138 * line character to terminate it. | |
| 139 */ | |
| 140 if (ch == 10 || ch == 13 || ch == 32 || ch == 9) | |
| 141 { | |
| 142 fclose(f); | |
| 143 return 1; | |
| 144 } | |
| 145 | |
| 146 state = SkipTag; | |
| 147 break; | |
| 148 | |
| 149 default: | |
| 150 png_error(png_ptr, "png_have_neon: internal error (bug)"); | |
| 151 } | |
| 152 } | |
| 153 } | |
| 154 | |
| 155 else | |
| 156 png_warning(png_ptr, "/proc/cpuinfo open failed"); | |
| 157 | |
| 158 return 0; | |
| 159 } |
