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 v3 next 12/17] tools/nolibc/printf: Handle "%s" with the numeric formats
Date: Mon, 23 Feb 2026 10:17:30 +0000 [thread overview]
Message-ID: <20260223101735.2922-13-david.laight.linux@gmail.com> (raw)
In-Reply-To: <20260223101735.2922-1-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>
---
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 6cb106367e3b..6dd27473ab7f 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') {
outstr = strerror(errno);
goto do_strlen_output;
--
2.39.5
next prev parent reply other threads:[~2026-02-23 11:00 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-23 10:17 [PATCH v3 next 00/17] Enhance printf() david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 01/17] tools/nolibc: Add _NOLIBC_OPTIMIZER_HIDE_VAR() to compiler.h david.laight.linux
2026-02-25 21:25 ` Thomas Weißschuh
2026-02-25 22:17 ` David Laight
2026-02-25 22:24 ` Thomas Weißschuh
2026-02-23 10:17 ` [PATCH v3 next 02/17] tools/nolibc: Optimise and common up the number to ascii functions david.laight.linux
2026-02-25 21:40 ` Thomas Weißschuh
2026-02-25 22:09 ` David Laight
2026-02-23 10:17 ` [PATCH v3 next 03/17] selftests/nolibc: Fix build with host headers and libc david.laight.linux
2026-02-25 21:24 ` Thomas Weißschuh
2026-02-23 10:17 ` [PATCH v3 next 04/17] selftests/nolibc: Improve reporting of vfprintf() errors david.laight.linux
2026-02-25 21:56 ` Thomas Weißschuh
2026-02-26 10:12 ` David Laight
2026-02-26 21:39 ` Thomas Weißschuh
2026-02-23 10:17 ` [PATCH v3 next 05/17] tools/nolibc: Implement strerror() in terms of strerror_r() david.laight.linux
2026-02-25 22:09 ` Thomas Weißschuh
2026-02-25 22:58 ` David Laight
2026-02-23 10:17 ` [PATCH v3 next 06/17] tools/nolibc/printf: Change variables 'c' to 'ch' and 'tmpbuf[]' to 'outbuf[]' david.laight.linux
2026-02-25 22:23 ` Thomas Weißschuh
2026-02-23 10:17 ` [PATCH v3 next 07/17] tools/nolibc/printf: Move snprintf length check to callback david.laight.linux
2026-02-25 22:37 ` Thomas Weißschuh
2026-02-25 23:12 ` David Laight
2026-02-26 21:29 ` Thomas Weißschuh
2026-02-26 22:11 ` David Laight
2026-02-23 10:17 ` [PATCH v3 next 08/17] tools/nolibc/printf: Output pad characters in 16 byte chunks david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 09/17] tools/nolibc/printf: Simplify __nolibc_printf() david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 10/17] tools/nolibc/printf: Use goto and reduce indentation david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 11/17] tools/nolibc/printf: Use bit-masks to hold requested flag, length and conversion chars david.laight.linux
2026-02-23 10:17 ` david.laight.linux [this message]
2026-02-23 10:17 ` [PATCH v3 next 13/17] tools/nolibc/printf: Add support for conversion flags david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 14/17] tools/nolibc/printf: Add support for left aligning fields david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 15/17] tools/nolibc/printf: Add support for zero padding and field precision david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 16/17] tools/nolibc/printf: Add support for octal output david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 17/17] selftests/nolibc: Use printf variable field widths and precisions david.laight.linux
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