diff options
Diffstat (limited to 'scripts/basic')
-rw-r--r-- | scripts/basic/Makefile | 2 | ||||
-rw-r--r-- | scripts/basic/hash.c | 64 |
2 files changed, 65 insertions, 1 deletions
diff --git a/scripts/basic/Makefile b/scripts/basic/Makefile index 4c324a1f1e0e..09559951df12 100644 --- a/scripts/basic/Makefile +++ b/scripts/basic/Makefile | |||
@@ -9,7 +9,7 @@ | |||
9 | # fixdep: Used to generate dependency information during build process | 9 | # fixdep: Used to generate dependency information during build process |
10 | # docproc: Used in Documentation/DocBook | 10 | # docproc: Used in Documentation/DocBook |
11 | 11 | ||
12 | hostprogs-y := fixdep docproc | 12 | hostprogs-y := fixdep docproc hash |
13 | always := $(hostprogs-y) | 13 | always := $(hostprogs-y) |
14 | 14 | ||
15 | # fixdep is needed to compile other host programs | 15 | # fixdep is needed to compile other host programs |
diff --git a/scripts/basic/hash.c b/scripts/basic/hash.c new file mode 100644 index 000000000000..3299ad7fc8c0 --- /dev/null +++ b/scripts/basic/hash.c | |||
@@ -0,0 +1,64 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2008 Red Hat, Inc., Jason Baron <jbaron@redhat.com> | ||
3 | * | ||
4 | */ | ||
5 | |||
6 | #include <stdio.h> | ||
7 | #include <stdlib.h> | ||
8 | #include <string.h> | ||
9 | |||
10 | #define DYNAMIC_DEBUG_HASH_BITS 6 | ||
11 | |||
12 | static const char *program; | ||
13 | |||
14 | static void usage(void) | ||
15 | { | ||
16 | printf("Usage: %s <djb2|r5> <modname>\n", program); | ||
17 | exit(1); | ||
18 | } | ||
19 | |||
20 | /* djb2 hashing algorithm by Dan Bernstein. From: | ||
21 | * http://www.cse.yorku.ca/~oz/hash.html | ||
22 | */ | ||
23 | |||
24 | unsigned int djb2_hash(char *str) | ||
25 | { | ||
26 | unsigned long hash = 5381; | ||
27 | int c; | ||
28 | |||
29 | c = *str; | ||
30 | while (c) { | ||
31 | hash = ((hash << 5) + hash) + c; | ||
32 | c = *++str; | ||
33 | } | ||
34 | return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1)); | ||
35 | } | ||
36 | |||
37 | unsigned int r5_hash(char *str) | ||
38 | { | ||
39 | unsigned long hash = 0; | ||
40 | int c; | ||
41 | |||
42 | c = *str; | ||
43 | while (c) { | ||
44 | hash = (hash + (c << 4) + (c >> 4)) * 11; | ||
45 | c = *++str; | ||
46 | } | ||
47 | return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1)); | ||
48 | } | ||
49 | |||
50 | int main(int argc, char *argv[]) | ||
51 | { | ||
52 | program = argv[0]; | ||
53 | |||
54 | if (argc != 3) | ||
55 | usage(); | ||
56 | if (!strcmp(argv[1], "djb2")) | ||
57 | printf("%d\n", djb2_hash(argv[2])); | ||
58 | else if (!strcmp(argv[1], "r5")) | ||
59 | printf("%d\n", r5_hash(argv[2])); | ||
60 | else | ||
61 | usage(); | ||
62 | exit(0); | ||
63 | } | ||
64 | |||