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pkg/mpaland-printf: wrap putc() and fputc() #21828

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Merged
maribu merged 1 commit into from
Oct 29, 2025
Merged

pkg/mpaland-printf: wrap putc() and fputc() #21828

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2 changes: 2 additions & 0 deletions pkg/mpaland-printf/Makefile.include
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,8 @@ LINKFLAGS += -Wl,-wrap=vdprintf
LINKFLAGS += -Wl,-wrap=vsprintf
LINKFLAGS += -Wl,-wrap=vsnprintf
LINKFLAGS += -Wl,-wrap=putchar
LINKFLAGS += -Wl,-wrap=putc
LINKFLAGS += -Wl,-wrap=fputc
LINKFLAGS += -Wl,-wrap=puts

# By wrapping the newlib only `_printf_common` symbol to the undefined
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24 changes: 18 additions & 6 deletions pkg/mpaland-printf/patches/0004-Wrapper-targets-Add-endpoints-for-Wl-wrap.patch
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Original file line number Diff line number Diff line change
@@ -1,15 +1,15 @@
From adf017ec04c42a615b536ee035db6d3f1eebdb31 Mon Sep 17 00:00:00 2001
From a01af4cb4991f6d5f0320f03d1f1d918df07caec Mon Sep 17 00:00:00 2001
From: Marian Buschsieweke <marian.buschsieweke@posteo.net>
Date: Sat, 11 May 2024 17:51:38 +0200
Subject: [PATCH 4/4] Wrapper targets: Add endpoints for -Wl,wrap=...
Subject: [PATCH] Wrapper targets: Add endpoints for -Wl,wrap=...

This adds aliases needed to wrap printf() and friends.
---
printf.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 87 insertions(+)
printf.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 99 insertions(+)

diff --git a/printf.c b/printf.c
index 7c1ac61..8a1311c 100644
index edf41d1..e00c3e5 100644
--- a/printf.c
+++ b/printf.c
@@ -32,6 +32,9 @@
Expand All @@ -22,7 +22,7 @@ index 7c1ac61..8a1311c 100644

#include "printf.h"
#include "stdio_base.h"
@@ -920,3 +923,87 @@ static void _putchar(char character)
@@ -920,3 +923,99 @@ static void _putchar(char character)
{
stdio_write(&character, sizeof(character));
}
Expand Down Expand Up @@ -54,7 +54,19 @@ index 7c1ac61..8a1311c 100644
+ _putchar((char)c);
+ return 1;
+}
+
+
+int __wrap_putc(int c, FILE *stream)
+{
+ (void)stream;
+ _putchar((char)c);
+ return 1;
+}
+
+
+__attribute__((alias("__wrap_putc")))
+int __wrap_fputc(int c, FILE *stream);
+
+
+int __wrap_puts(const char *s)
+{
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