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charset=us-ascii Content-Disposition: inline In-Reply-To: <20260302101815.3043-20-david.laight.linux@gmail.com> On Mon, Mar 02, 2026 at 10:18:11AM +0000, david.laight.linux@gmail.com wrote: > From: David Laight > > The output for %#x is almost the same as that for %p, both output in > hexadecimal with a leading "0x". > However for zero %#x should just output "0" (the same as decimal and ocal). > For %p match glibc and output "(nil)" rather than "0x0" or "0". > > Add tests for "%#x", "% d", "%+d" and passing NULL to "%p". > > Signed-off-by: David Laight Acked-by: Willy Tarreau Willy > --- > > v4: Split into its' own patch. > > tools/include/nolibc/stdio.h | 38 ++++++++++++++------ > tools/testing/selftests/nolibc/nolibc-test.c | 3 ++ > 2 files changed, 30 insertions(+), 11 deletions(-) > > diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h > index 5d75e8530ce2..ef8e7069d5cf 100644 > --- a/tools/include/nolibc/stdio.h > +++ b/tools/include/nolibc/stdio.h > @@ -296,7 +296,7 @@ int fseek(FILE *stream, long offset, int whence) > * - %% generates a single % > * - %m outputs strerror(errno). > * - %X outputs a..f the same as %x. > - * - The modifiers [#-0] are currently ignored. > + * - The modifiers [-0] are currently ignored. > * - No support for precision or variable widths. > * - No support for floating point or wide characters. > * - Invalid formats are copied to the output buffer. > @@ -410,8 +410,11 @@ int __nolibc_printf(__nolibc_printf_cb cb, void *state, const char *fmt, va_list > * so that 'X' can be allowed through. > * 'X' gets treated and 'x' because _NOLIBC_PF_FLAG() returns the same > * value for both. > + * > + * We need to check for "%p" or "%#x" later, merging here gives better code. > + * But '#' collides with 'c' so shift right. > */ > - ch_flag = _NOLIBC_PF_FLAG(ch); > + ch_flag = _NOLIBC_PF_FLAG(ch) | (flags & _NOLIBC_PF_FLAG('#')) >> 1; > if (((ch >= 'a' && ch <= 'z') || ch == 'X') && > _NOLIBC_PF_FLAGS_CONTAIN(ch_flag, 'c', 'd', 'i', 'u', 'x', 'p', 's')) { > /* 'long' is needed for pointer/string conversions and ltz lengths. > @@ -470,17 +473,30 @@ int __nolibc_printf(__nolibc_printf_cb cb, void *state, const char *fmt, va_list > */ > out = outbuf + 2; > > - /* Convert the number to ascii in the required base. */ > - if (_NOLIBC_PF_FLAGS_CONTAIN(ch_flag, 'd', 'i', 'u')) { > - /* Base 10 */ > - len = u64toa_r(v, out); > - } else { > - /* Base 16 */ > + if (v == 0) { > + /* There are special rules for zero. */ > if (_NOLIBC_PF_FLAGS_CONTAIN(ch_flag, 'p')) { > - /* "%p" needs "0x" prepending. */ > - sign_prefix = 'x' | '0' << 8; > + /* "%p" match glibc, precision is ignored */ > + outstr = "(nil)"; > + len = 5; > + goto do_output; > + } > + /* All other formats (including "%#x") just output "0". */ > + out[0] = '0'; > + len = 1; > + } else { > + /* Convert the number to ascii in the required base. */ > + if (_NOLIBC_PF_FLAGS_CONTAIN(ch_flag, 'd', 'i', 'u')) { > + /* Base 10 */ > + len = u64toa_r(v, out); > + } else { > + /* Base 16 */ > + if (_NOLIBC_PF_FLAGS_CONTAIN(ch_flag, 'p', '#' - 1)) { > + /* "%p" and "%#x" need "0x" prepending. */ > + sign_prefix = 'x' | '0' << 8; > + } > + len = u64toh_r(v, out); > } > - len = u64toh_r(v, out); > } > > /* Add the 0, 1 or 2 ("0x") sign/prefix characters at the front. */ > diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c > index a140c54e4d72..4267c69ec37c 100644 > --- a/tools/testing/selftests/nolibc/nolibc-test.c > +++ b/tools/testing/selftests/nolibc/nolibc-test.c > @@ -1825,6 +1825,7 @@ static int run_printf(int min, int max) > CASE_TEST(string); EXPECT_VFPRINTF(1, "foo", "%s", "foo"); break; > CASE_TEST(number); EXPECT_VFPRINTF(1, "1234", "%d", 1234); break; > CASE_TEST(negnumber); EXPECT_VFPRINTF(1, "-1234", "%d", -1234); break; > + CASE_TEST(num_sign); EXPECT_VFPRINTF(1, "| 1|+2|+3|+4|5|", "|% d|%+d|% +d|%+ d|%#d|", 1, 2, 3, 4, 5); break; > CASE_TEST(unsigned); EXPECT_VFPRINTF(1, "12345", "%u", 12345); break; > CASE_TEST(signed_max); EXPECT_VFPRINTF(1, "2147483647", "%i", ~0u >> 1); break; > CASE_TEST(signed_min); EXPECT_VFPRINTF(1, "-2147483648", "%i", (~0u >> 1) + 1); break; > @@ -1832,7 +1833,9 @@ static int run_printf(int min, int max) > CASE_TEST(char); EXPECT_VFPRINTF(1, "c", "%c", 'c'); break; > CASE_TEST(hex_nolibc); EXPECT_VFPRINTF(is_nolibc, "|f|d|", "|%x|%X|", 0xf, 0xd); break; > CASE_TEST(hex_libc); EXPECT_VFPRINTF(!is_nolibc, "|f|D|", "|%x|%X|", 0xf, 0xd); break; > + CASE_TEST(hex_alt); EXPECT_VFPRINTF(1, "|0x1| 0x2| 0|", "|%#x|%#5x|%#5x|", 1, 2, 0); break; > CASE_TEST(pointer); EXPECT_VFPRINTF(1, "0x1", "%p", (void *) 0x1); break; > + CASE_TEST(pointer_NULL); EXPECT_VFPRINTF(1, "(nil)", "%p", (void *)0); break; > CASE_TEST(percent); EXPECT_VFPRINTF(1, "a%d42%69%", "a%%d%d%%%d%%", 42, 69); break; > CASE_TEST(perc_qual); EXPECT_VFPRINTF(1, "a%d2", "a%-14l%d%d", 2); break; > CASE_TEST(invalid); EXPECT_VFPRINTF(1, "a%12yx3%y42%P", "a%12yx%d%y%d%P", 3, 42); break; > -- > 2.39.5