[PATCH v5 next 14/17] tools/nolibc/printf: Add support for left aligning fields

[david.laight.linux@gmail.com]

From: David Laight <david.laight.linux@gmail.com>

Output the characters before or after the pad - writing the pad takes more code.

Include additional/changed tests

Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David Laight <david.laight.linux@gmail.com>

---
Unchanged for v4 and v5.

Changes for v3:
- Formally part of patch 7.

 tools/include/nolibc/stdio.h                 | 6 +++++-
 tools/testing/selftests/nolibc/nolibc-test.c | 4 +++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index 4bb4d08d834e..fccc8a2d9b8a 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -546,7 +546,11 @@ int __nolibc_printf(__nolibc_printf_cb cb, void *state, const char *fmt, va_list
 		/* Stop gcc back-merging this code into one of the conditionals above. */
 		_NOLIBC_OPTIMIZER_HIDE_VAR(len);
 
+		/* Output the characters on the required side of any padding. */
 		width -= len;
+		flags = _NOLIBC_PF_FLAGS_CONTAIN(flags, '-');
+		if (flags && cb(state, outstr, len) != 0)
+			return -1;
 		while (width > 0) {
 			/* Output pad in 16 byte blocks with the small block first. */
 			int pad_len = ((width - 1) & 15) + 1;
@@ -555,7 +559,7 @@ int __nolibc_printf(__nolibc_printf_cb cb, void *state, const char *fmt, va_list
 			if (cb(state, "                ", pad_len) != 0)
 				return -1;
 		}
-		if (cb(state, outstr, len) != 0)
+		if (!flags && cb(state, outstr, len) != 0)
 			return -1;
 	}
 
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 4267c69ec37c..89ded1dd7318 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1845,9 +1845,11 @@ static int run_printf(int min, int max)
 		CASE_TEST(truncation);   EXPECT_VFPRINTF(1, "0123456789012345678901234", "%s", "0123456789012345678901234"); break;
 		CASE_TEST(string_width); EXPECT_VFPRINTF(1, "         1", "%10s", "1"); break;
 		CASE_TEST(number_width); EXPECT_VFPRINTF(1, "         1", "%10d", 1); break;
+		CASE_TEST(number_left);  EXPECT_VFPRINTF(1, "|-5      |", "|%-8d|", -5); break;
+		CASE_TEST(string_align); EXPECT_VFPRINTF(1, "|foo     |", "|%-8s|", "foo"); break;
 		CASE_TEST(width_trunc);  EXPECT_VFPRINTF(1, "                        1", "%25d", 1); break;
 		CASE_TEST(errno);        errno = 22; EXPECT_VFPRINTF(is_nolibc, "errno=22", "%m"); break;
-		CASE_TEST(errno-neg);    errno = -22; EXPECT_VFPRINTF(is_nolibc, "   errno=-22", "%12m"); break;
+		CASE_TEST(errno-neg);    errno = -22; EXPECT_VFPRINTF(is_nolibc, "errno=-22   ", "%-12m"); break;
 		CASE_TEST(scanf);        EXPECT_ZR(1, test_scanf()); break;
 		CASE_TEST(printf_error); EXPECT_ZR(1, test_printf_error()); break;
 		case __LINE__:
-- 
2.39.5