| Message ID | aeb48b9cf6fc4674f7560166f22c7dc87d02302d.1685362482.git.falcon@tinylab.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | nolibc: add generic part1 of prepare for rv32 | expand |
On Mon, May 29, 2023 at 09:00:01PM +0800, Zhangjin Wu wrote: > Compiling nolibc-test.c with gcc on x86_64 got such warning: > > tools/testing/selftests/nolibc/nolibc-test.c: In function 'expect_eq': > tools/testing/selftests/nolibc/nolibc-test.c:177:24: warning: format '%lld' expects argument of type 'long long int', but argument 2 has type 'uint64_t' {aka 'long unsigned int'} [-Wformat=] > 177 | llen += printf(" = %lld ", expr); > | ~~~^ ~~~~ > | | | > | | uint64_t {aka long unsigned int} > | long long int > | %ld > > It because that glibc defines uint64_t as "unsigned long int" when word > size (means sizeof(long)) is 64bit (see include/bits/types.h), but > nolibc directly use the 64bit "unsigned long long" (see > tools/include/nolibc/stdint.h), which is simpler, seems kernel uses it > too (include/uapi/asm-generic/int-ll64.h). > > It is able to do like glibc, defining __WORDSIZE for all of platforms > and using "unsigned long int" to define uint64_t when __WORDSIZE is > 64bits, but here uses a simpler solution: nolibc always requires %lld to > match "unsigned long long", for others, only require %lld when word size > is 32bit. > > Signed-off-by: Zhangjin Wu <falcon@tinylab.org> > --- > tools/testing/selftests/nolibc/nolibc-test.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c > index d417ca5d976f..7f9b716fd9b1 100644 > --- a/tools/testing/selftests/nolibc/nolibc-test.c > +++ b/tools/testing/selftests/nolibc/nolibc-test.c > @@ -174,7 +174,11 @@ static int expect_eq(uint64_t expr, int llen, uint64_t val) > { > int ret = !(expr == val); > > +#if __SIZEOF_LONG__ == 4 || defined(NOLIBC) > llen += printf(" = %lld ", expr); > +#else > + llen += printf(" = %ld ", expr); > +#endif > pad_spc(llen, 64, ret ? "[FAIL]\n" : " [OK]\n"); > return ret; > } Please don't proceed like this. There's much easier to do here for a printf, just cast the expression to the type printf expects: - llen += printf(" = %lld ", expr); + llen += printf(" = %lld ", (long long)expr); Willy
> On Mon, May 29, 2023 at 09:00:01PM +0800, Zhangjin Wu wrote: > > Compiling nolibc-test.c with gcc on x86_64 got such warning: > > > > tools/testing/selftests/nolibc/nolibc-test.c: In function 'expect_eq': > > tools/testing/selftests/nolibc/nolibc-test.c:177:24: warning: format '%lld' expects argument of type 'long long int', but argument 2 has type 'uint64_t' {aka 'long unsigned int'} [-Wformat=] > > 177 | llen += printf(" = %lld ", expr); > > | ~~~^ ~~~~ > > | | | > > | | uint64_t {aka long unsigned int} > > | long long int > > | %ld > > > > It because that glibc defines uint64_t as "unsigned long int" when word > > size (means sizeof(long)) is 64bit (see include/bits/types.h), but > > nolibc directly use the 64bit "unsigned long long" (see > > tools/include/nolibc/stdint.h), which is simpler, seems kernel uses it > > too (include/uapi/asm-generic/int-ll64.h). > > > > It is able to do like glibc, defining __WORDSIZE for all of platforms > > and using "unsigned long int" to define uint64_t when __WORDSIZE is > > 64bits, but here uses a simpler solution: nolibc always requires %lld to > > match "unsigned long long", for others, only require %lld when word size > > is 32bit. > > > > Signed-off-by: Zhangjin Wu <falcon@tinylab.org> > > --- > > tools/testing/selftests/nolibc/nolibc-test.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c > > index d417ca5d976f..7f9b716fd9b1 100644 > > --- a/tools/testing/selftests/nolibc/nolibc-test.c > > +++ b/tools/testing/selftests/nolibc/nolibc-test.c > > @@ -174,7 +174,11 @@ static int expect_eq(uint64_t expr, int llen, uint64_t val) > > { > > int ret = !(expr == val); > > > > +#if __SIZEOF_LONG__ == 4 || defined(NOLIBC) > > llen += printf(" = %lld ", expr); > > +#else > > + llen += printf(" = %ld ", expr); > > +#endif > > pad_spc(llen, 64, ret ? "[FAIL]\n" : " [OK]\n"); > > return ret; > > } > > Please don't proceed like this. There's much easier to do here for a printf, > just cast the expression to the type printf expects: > > - llen += printf(" = %lld ", expr); > + llen += printf(" = %lld ", (long long)expr); Yes, this conversion is better, my method make things more complex ;-) Thanks, Zhangjin > > Willy
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index d417ca5d976f..7f9b716fd9b1 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -174,7 +174,11 @@ static int expect_eq(uint64_t expr, int llen, uint64_t val) { int ret = !(expr == val); +#if __SIZEOF_LONG__ == 4 || defined(NOLIBC) llen += printf(" = %lld ", expr); +#else + llen += printf(" = %ld ", expr); +#endif pad_spc(llen, 64, ret ? "[FAIL]\n" : " [OK]\n"); return ret; }
Compiling nolibc-test.c with gcc on x86_64 got such warning: tools/testing/selftests/nolibc/nolibc-test.c: In function ‘expect_eq’: tools/testing/selftests/nolibc/nolibc-test.c:177:24: warning: format ‘%lld’ expects argument of type ‘long long int’, but argument 2 has type ‘uint64_t’ {aka ‘long unsigned int’} [-Wformat=] 177 | llen += printf(" = %lld ", expr); | ~~~^ ~~~~ | | | | | uint64_t {aka long unsigned int} | long long int | %ld It because that glibc defines uint64_t as "unsigned long int" when word size (means sizeof(long)) is 64bit (see include/bits/types.h), but nolibc directly use the 64bit "unsigned long long" (see tools/include/nolibc/stdint.h), which is simpler, seems kernel uses it too (include/uapi/asm-generic/int-ll64.h). It is able to do like glibc, defining __WORDSIZE for all of platforms and using "unsigned long int" to define uint64_t when __WORDSIZE is 64bits, but here uses a simpler solution: nolibc always requires %lld to match "unsigned long long", for others, only require %lld when word size is 32bit. Signed-off-by: Zhangjin Wu <falcon@tinylab.org> --- tools/testing/selftests/nolibc/nolibc-test.c | 4 ++++ 1 file changed, 4 insertions(+)