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-rw-r--r--scripts/basic/Makefile2
-rw-r--r--scripts/basic/hash.c64
2 files changed, 65 insertions, 1 deletions
diff --git a/scripts/basic/Makefile b/scripts/basic/Makefile
index 4c324a1f1e0..09559951df1 100644
--- a/scripts/basic/Makefile
+++ b/scripts/basic/Makefile
@@ -9,7 +9,7 @@
# fixdep: Used to generate dependency information during build process
# docproc: Used in Documentation/DocBook
-hostprogs-y := fixdep docproc
+hostprogs-y := fixdep docproc hash
always := $(hostprogs-y)
# 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 00000000000..3299ad7fc8c
--- /dev/null
+++ b/scripts/basic/hash.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2008 Red Hat, Inc., Jason Baron <jbaron@redhat.com>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define DYNAMIC_DEBUG_HASH_BITS 6
+
+static const char *program;
+
+static void usage(void)
+{
+ printf("Usage: %s <djb2|r5> <modname>\n", program);
+ exit(1);
+}
+
+/* djb2 hashing algorithm by Dan Bernstein. From:
+ * http://www.cse.yorku.ca/~oz/hash.html
+ */
+
+unsigned int djb2_hash(char *str)
+{
+ unsigned long hash = 5381;
+ int c;
+
+ c = *str;
+ while (c) {
+ hash = ((hash << 5) + hash) + c;
+ c = *++str;
+ }
+ return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1));
+}
+
+unsigned int r5_hash(char *str)
+{
+ unsigned long hash = 0;
+ int c;
+
+ c = *str;
+ while (c) {
+ hash = (hash + (c << 4) + (c >> 4)) * 11;
+ c = *++str;
+ }
+ return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1));
+}
+
+int main(int argc, char *argv[])
+{
+ program = argv[0];
+
+ if (argc != 3)
+ usage();
+ if (!strcmp(argv[1], "djb2"))
+ printf("%d\n", djb2_hash(argv[2]));
+ else if (!strcmp(argv[1], "r5"))
+ printf("%d\n", r5_hash(argv[2]));
+ else
+ usage();
+ exit(0);
+}
+