-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, as already discussed on debian-devel, I would like to draw your attention to a potential runtime problem for each package on arm, powerpc and s390.
As I experienced, a lot of people assume that char is signed per default. This is _not_ true on arm, powerpc and s390. The following explanation of a typical problem can be found at http://www.purdue.edu/PUCC/Short-Courses/c.files/p_00975.html >>The following code fragment will ignore the end-of-file when char is >>implemented using unsigned char, due to internal conversions between data >>types: >> >> char c; >> while ((c = getchar()) != EOF) >> process character in c >> >>EOF is usually -1. When getchar() returns a -1, that value immediately goes >>into an instance of type plain char, c. If plain char is not signed, then >>an internal conversion copies the low-order bits of -1 into c; now c is 255. >>Moreover, EOF, which is signed, finds itself to be the right hand operand >>in a mixed-mode expression involving an unsigned operand. In this case, >>the signed value is raised to an unsigned value; -1 now becomes 65,535. >>Finally, 255 is never equal to 65,535; the relational test is always true; >>and the EOF is ignored. The correction is to make the type of variable c >>int. In other contexts the right solution is to make the type of the variable 'signed char'. In most cases the compiler will issue one of the following warnings: comparison is always true due to limited range of data type comparison is always false due to limited range of data type comparison of unsigned expression >= 0 is always true initialization of negative value \`-1' to \`char' pointer targets in assignment differ in signedness pointer targets in passing arg 1 of \`...' differ in signedness Please check the build log of your package on one of the platforms mentioned above for the warnings. A not complete list of packages that have got this problem ordered by package owner can be found at http://lists.debian.org/debian-devel/2001/debian-devel-200112/msg02114.html The build logs of these packages are at http://buildd.debian.org or at http://people.debian.org/~gt/ . Regards, Gerhard -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE8Qd352m0l3zLXWBIRAnuHAJ0SC5tKq0MpzckgA2ebGIDTW29RvwCgolK5 uTYFxUMRE1h91GonZuv49wg= =nUkF -----END PGP SIGNATURE-----
