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From: david.laight.linux@gmail.com
To: "Willy Tarreau" <w@1wt.eu>,
	"Thomas Weißschuh" <linux@weissschuh.net>,
	linux-kernel@vger.kernel.org, "Cheng Li" <lechain@gmail.com>
Cc: David Laight <david.laight.linux@gmail.com>
Subject: [PATCH v4 next 16/23] tools/nolibc/printf: Handle "%s" with the numeric formats
Date: Mon,  2 Mar 2026 10:18:08 +0000	[thread overview]
Message-ID: <20260302101815.3043-17-david.laight.linux@gmail.com> (raw)
In-Reply-To: <20260302101815.3043-1-david.laight.linux@gmail.com>

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

Avoids the extra va_arg() call with is non-trivial on a lot of
modern ABI.

Signed-off-by: David Laight <david.laight.linux@gmail.com>
---

Unchanched for v4.

Changes for v3:
- Moved to its own patch (part of patch 7 in v2)..
- Fix 32bit compile.

 tools/include/nolibc/stdio.h | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index 4c7626dbd63f..484432ca87d5 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -412,13 +412,13 @@ int __nolibc_printf(__nolibc_printf_cb cb, void *state, const char *fmt, va_list
 		 */
 		ch_flag = _NOLIBC_PF_FLAG(ch);
 		if (((ch >= 'a' && ch <= 'z') || ch == 'X') &&
-		    _NOLIBC_PF_FLAGS_CONTAIN(ch_flag, 'c', 'd', 'i', 'u', 'x', 'p')) {
-			/* 'long' is needed for pointer conversions and ltz lengths.
+		    _NOLIBC_PF_FLAGS_CONTAIN(ch_flag, 'c', 'd', 'i', 'u', 'x', 'p', 's')) {
+			/* 'long' is needed for pointer/string conversions and ltz lengths.
 			 * A single test can be used provided 'p' (the same bit as '0')
 			 * is masked from flags.
 			 */
 			if (_NOLIBC_PF_FLAGS_CONTAIN(ch_flag | (flags & ~_NOLIBC_PF_FLAG('p')),
-						     'p', 'l', 't', 'z')) {
+						     'p', 's', 'l', 't', 'z')) {
 				v = va_arg(args, unsigned long);
 				signed_v = (long)v;
 			} else if (_NOLIBC_PF_FLAGS_CONTAIN(flags, 'j', 'q')) {
@@ -437,6 +437,15 @@ int __nolibc_printf(__nolibc_printf_cb cb, void *state, const char *fmt, va_list
 				goto do_output;
 			}
 
+			if (ch == 's') {
+				/* "%s" - character string. */
+				outstr = (const char  *)(uintptr_t)v;
+				if (!outstr) {
+					outstr = "(null)";
+				}
+				goto do_strlen_output;
+			}
+
 			out = outbuf;
 
 			if (_NOLIBC_PF_FLAGS_CONTAIN(ch_flag, 'd', 'i')) {
@@ -465,13 +474,6 @@ int __nolibc_printf(__nolibc_printf_cb cb, void *state, const char *fmt, va_list
 			goto do_strlen_output;
 		}
 
-		if (ch == 's') {
-			outstr = va_arg(args, char *);
-			if (!outstr)
-				outstr="(null)";
-			goto do_strlen_output;
-		}
-
 		if (ch == 'm') {
 #ifdef NOLIBC_IGNORE_ERRNO
 			outstr = "unknown error";
-- 
2.39.5


  parent reply	other threads:[~2026-03-02 10:18 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-02 10:17 [PATCH v4 next 00/23] Enhance printf() david.laight.linux
2026-03-02 10:17 ` [PATCH v4 next 01/23] tools/nolibc: Add _NOLIBC_OPTIMIZER_HIDE_VAR() to compiler.h david.laight.linux
2026-03-07 10:50   ` Willy Tarreau
2026-03-02 10:17 ` [PATCH v4 next 02/23] tools/nolibc/printf: Move snprintf length check to callback david.laight.linux
2026-03-07 10:48   ` Willy Tarreau
2026-03-02 10:17 ` [PATCH v4 next 03/23] selftests/nolibc: Return correct value when printf test fails david.laight.linux
2026-03-02 10:17 ` [PATCH v4 next 04/23] selftests/nolibc: check vsnprintf() output buffer before the length david.laight.linux
2026-03-02 10:17 ` [PATCH v4 next 05/23] selftests/nolibc: Use length of 'expected' string to check snprintf() output david.laight.linux
2026-03-02 10:17 ` [PATCH v4 next 06/23] selftests/nolibc: Check that snprintf() doesn't write beyond the buffer end david.laight.linux
2026-03-02 10:17 ` [PATCH v4 next 07/23] selftests/nolibc: Let EXPECT_VFPRINTF() tests be skipped david.laight.linux
2026-03-02 10:18 ` [PATCH 08/23] selftests/nolibc: Rename w to written in expect_vfprintf() david.laight.linux
2026-03-02 10:18 ` [PATCH v4 next 09/23] tools/nolibc: Implement strerror() in terms of strerror_r() david.laight.linux
2026-03-07 10:18   ` Willy Tarreau
2026-03-07 11:31     ` David Laight
2026-03-07 11:37       ` Willy Tarreau
2026-03-07 16:55         ` David Laight
2026-03-07 17:17           ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 10/23] tools/nolibc: Rename the 'errnum' parameter to strerror() david.laight.linux
2026-03-07 10:19   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 11/23] tools/nolibc/printf: Output pad characters in 16 byte chunks david.laight.linux
2026-03-02 10:18 ` [PATCH 12/23] tools/nolibc/printf: Simplify __nolibc_printf() david.laight.linux
2026-03-02 10:18 ` [PATCH v4 next 13/23] tools/nolibc/printf: Use goto and reduce indentation david.laight.linux
2026-03-07 10:30   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH 14/23] tools/nolibc/printf: Use bit-masks to hold requested flag, length and conversion chars david.laight.linux
2026-03-02 10:18 ` [PATCH v4 next 15/23] tools/nolibc/printf: Add support for length modifiers tzqL and formats iX david.laight.linux
2026-03-02 10:18 ` david.laight.linux [this message]
2026-03-07 10:32   ` [PATCH v4 next 16/23] tools/nolibc/printf: Handle "%s" with the numeric formats Willy Tarreau
2026-03-02 10:18 ` [PATCH 17/23] tools/nolibc/printf: Prepend sign to converted number david.laight.linux
2026-03-07 10:40   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 18/23] tools/nolibc/printf: Add support for conversion flags space and plus david.laight.linux
2026-03-07 10:46   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 19/23] tools/nolibc/printf: Special case 0 and add support for %#x david.laight.linux
2026-03-07 10:46   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 20/23] tools/nolibc/printf: Add support for left aligning fields david.laight.linux
2026-03-07 10:46   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 21/23] tools/nolibc/printf: Add support for zero padding and field precision david.laight.linux
2026-03-02 10:18 ` [PATCH v4 next 22/23] tools/nolibc/printf: Add support for octal output david.laight.linux
2026-03-07 10:45   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 23/23] selftests/nolibc: Use printf variable field widths and precisions david.laight.linux
2026-03-07 10:53 ` [PATCH v4 next 00/23] Enhance printf() Willy Tarreau
2026-03-07 18:02 ` Thomas Weißschuh
2026-03-07 22:03   ` David Laight
2026-03-07 22:20     ` Thomas Weißschuh
2026-03-08  9:23   ` Willy Tarreau

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