Commits

Anonymous committed 192a6be

fix signed range problems with hex conversions

Make hexval_table[] "const". Also make sure that the accessor
function hexval() does not access the table with out-of-range
values by declaring its parameter "unsigned char", instead of
"unsigned int".

With this, gcc can just generate:

movzbl (%rdi), %eax
movsbl hexval_table(%rax),%edx
movzbl 1(%rdi), %eax
movsbl hexval_table(%rax),%eax
sall $4, %edx
orl %eax, %edx

for the code to generate a byte from two hex characters.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Comments (0)

Files changed (2)

 extern int has_pack_file(const unsigned char *sha1);
 extern int has_pack_index(const unsigned char *sha1);
 
-extern signed char hexval_table[256];
-static inline unsigned int hexval(unsigned int c)
+extern const signed char hexval_table[256];
+static inline unsigned int hexval(unsigned char c)
 {
 	return hexval_table[c];
 }
 
 static unsigned int sha1_file_open_flag = O_NOATIME;
 
-signed char hexval_table[256] = {
+const signed char hexval_table[256] = {
 	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 00-07 */
 	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 08-0f */
 	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 10-17 */