static_cast char to unsigned on BIG_ENDIAN platforms may cause errors

[cmumford]

Original issue 35 created by Alexander.Klishin on 2011-08-23T06:31:19.000Z:

util/coding_test may fail on some BIG_ENDIAN platforms

uname -ms
HP-UX ia64

gcc version 4.3.3 (GCC)

micro test:
====cast.cpp ====

include <stdio.h>

int main(int ac, char *av[]) {
char c = -1;
printf("cast1=%u cast2=%u",
static_cast<unsigned int>(c), //!!! wrong conversion
static_cast<unsigned int>(static_cast<unsigned char>(c)));

}

g++ cast.cpp -o cast

./cast

cast1=4294967295 cast2=255

Problem in file "util\coding.h"
inline uint32_t DecodeFixed32(const char* ptr) {
...
return ((static_cast<uint32_t>(ptr[0]))
| (static_cast<uint32_t>(ptr[1]) << 8)
| (static_cast<uint32_t>(ptr[2]) << 16)
| (static_cast<uint32_t>(ptr[3]) << 24));
}

Should be:
return ((static_cast<uint32_t>(static_cast<unsigned char>(ptr[0])))
| (static_cast<uint32_t>(static_cast<unsigned char>(ptr[1])) << 8)
| (static_cast<uint32_t>(static_cast<unsigned char>(ptr[2])) << 16)
| (static_cast<uint32_t>(static_cast<unsigned char>(ptr[3])) << 24));

[cmumford]

Comment #1 originally posted by gabor@google.com on 2011-09-23T22:58:32.000Z:

Thanks for this! Could you please try out the patch here:
http://code.google.com/p/leveldb/issues/detail?id=36

And see if that fixes your problem?

Let me know - thanks, Gabor

[cmumford]

Comment #2 originally posted by Alexander.Klishin on 2011-09-30T11:20:01.000Z:

This patch fixes problem.
Now test "crc32c_test" works without errors.

My platform is HP-UX 11.31 ia64
Also tested on Win32/Win64/Linux i686.

[cmumford]

Comment #3 originally posted by gabor@google.com on 2011-10-05T23:28:00.000Z:

This issue was closed by revision e028bdf.

[cmumford]

Comment #4 originally posted by gabor@google.com on 2011-10-05T23:31:07.000Z:

This issue was closed by revision 299cced.

[cmumford]

Comment #5 originally posted by gabor@google.com on 2011-10-05T23:35:06.000Z:

This issue was closed by revision r53.

[cmumford]

Comment #6 originally posted by dgrogan@chromium.org on 2012-06-01T23:55:51.000Z:

Issue 36 has been merged into this issue.