This was prompted by the discussion about output directory support with O=. It seems sometimes we were pulling in system headers making testing annoying and unreliable.
Willy:
I did not implement the '#ifdef va_start` guard that we discussed before. In my understanding the latest agreement does not need it anymore. Please let me know if this is incorrect.
Signed-off-by: Thomas Weißschuh linux@weissschuh.net --- Changes in v2: - Adapt comment in nolibc.h - <stdarg.h> -> "stdarg.h" - Link to v1: https://lore.kernel.org/r/20230827-nolibc-nostdinc-v1-0-995d1811f1f3@weisssc...
--- Thomas Weißschuh (2): tools/nolibc: add stdarg.h header selftests/nolibc: use -nostdinc for nolibc-test
tools/include/nolibc/Makefile | 1 + tools/include/nolibc/nolibc.h | 4 ++-- tools/include/nolibc/stdarg.h | 16 ++++++++++++++++ tools/include/nolibc/stdio.h | 3 +-- tools/include/nolibc/sys.h | 2 +- tools/testing/selftests/nolibc/Makefile | 2 +- 6 files changed, 22 insertions(+), 6 deletions(-) --- base-commit: 556fb7131e03b0283672fb40f6dc2d151752aaa7 change-id: 20230827-nolibc-nostdinc-203908130d67
Best regards,
This allows nolic to work with `-nostdinc` avoiding any reliance on system headers.
The implementation has been lifted from musl libc 1.2.4. There is already an implementation of stdarg.h in include/linux/stdarg.h but that is GPL licensed and therefore not suitable for nolibc.
The used compiler builtins have been validated to be at least available since GCC 4.1.2 and clang 3.0.0.
Signed-off-by: Thomas Weißschuh linux@weissschuh.net --- tools/include/nolibc/Makefile | 1 + tools/include/nolibc/nolibc.h | 4 ++-- tools/include/nolibc/stdarg.h | 16 ++++++++++++++++ tools/include/nolibc/stdio.h | 3 +-- tools/include/nolibc/sys.h | 2 +- 5 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/tools/include/nolibc/Makefile b/tools/include/nolibc/Makefile index 909b6eb500fe..e69c26abe1ea 100644 --- a/tools/include/nolibc/Makefile +++ b/tools/include/nolibc/Makefile @@ -34,6 +34,7 @@ all_files := \ signal.h \ stackprotector.h \ std.h \ + stdarg.h \ stdint.h \ stdlib.h \ string.h \ diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h index 1f8d821000ac..989e707263a4 100644 --- a/tools/include/nolibc/nolibc.h +++ b/tools/include/nolibc/nolibc.h @@ -74,10 +74,10 @@ * -I../nolibc -o hello hello.c -lgcc * * The available standard (but limited) include files are: - * ctype.h, errno.h, signal.h, stdio.h, stdlib.h, string.h, time.h + * ctype.h, errno.h, signal.h, stdarg.h, stdio.h, stdlib.h, string.h, time.h * * In addition, the following ones are expected to be provided by the compiler: - * float.h, stdarg.h, stddef.h + * float.h, stddef.h * * The following ones which are part to the C standard are not provided: * assert.h, locale.h, math.h, setjmp.h, limits.h diff --git a/tools/include/nolibc/stdarg.h b/tools/include/nolibc/stdarg.h new file mode 100644 index 000000000000..c628b5783da6 --- /dev/null +++ b/tools/include/nolibc/stdarg.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ +/* + * Variadic argument support for NOLIBC + * Copyright (C) 2005-2020 Rich Felker, et al. + */ + +#ifndef _NOLIBC_STDARG_H +#define _NOLIBC_STDARG_H + +typedef __builtin_va_list va_list; +#define va_start(v, l) __builtin_va_start(v, l) +#define va_end(v) __builtin_va_end(v) +#define va_arg(v, l) __builtin_va_arg(v, l) +#define va_copy(d, s) __builtin_va_copy(d, s) + +#endif /* _NOLIBC_STDARG_H */ diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h index cae402c11e57..d7ef43973916 100644 --- a/tools/include/nolibc/stdio.h +++ b/tools/include/nolibc/stdio.h @@ -7,13 +7,12 @@ #ifndef _NOLIBC_STDIO_H #define _NOLIBC_STDIO_H
-#include <stdarg.h> - #include "std.h" #include "arch.h" #include "errno.h" #include "types.h" #include "sys.h" +#include "stdarg.h" #include "stdlib.h" #include "string.h"
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index fdb6bd6c0e2f..b478750c9004 100644 --- a/tools/include/nolibc/sys.h +++ b/tools/include/nolibc/sys.h @@ -7,7 +7,6 @@ #ifndef _NOLIBC_SYS_H #define _NOLIBC_SYS_H
-#include <stdarg.h> #include "std.h"
/* system includes */ @@ -25,6 +24,7 @@
#include "arch.h" #include "errno.h" +#include "stdarg.h" #include "types.h"
Avoid any accidental reliance on system includes.
Signed-off-by: Thomas Weißschuh linux@weissschuh.net --- tools/testing/selftests/nolibc/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile index dfe66776a331..689658f81a19 100644 --- a/tools/testing/selftests/nolibc/Makefile +++ b/tools/testing/selftests/nolibc/Makefile @@ -170,7 +170,7 @@ sysroot/$(ARCH)/include: ifneq ($(NOLIBC_SYSROOT),0) nolibc-test: nolibc-test.c sysroot/$(ARCH)/include $(QUIET_CC)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ \ - -nostdlib -static -Isysroot/$(ARCH)/include $< -lgcc + -nostdlib -nostdinc -static -Isysroot/$(ARCH)/include $< -lgcc else nolibc-test: nolibc-test.c $(QUIET_CC)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ \
On Wed, Aug 30, 2023 at 05:07:11PM +0200, Thomas Weißschuh wrote:
This was prompted by the discussion about output directory support with O=. It seems sometimes we were pulling in system headers making testing annoying and unreliable.
Willy:
I did not implement the '#ifdef va_start` guard that we discussed before. In my understanding the latest agreement does not need it anymore. Please let me know if this is incorrect.
No that's fine given your goal of including just "nolibc.h" and no other regular include file, I agree. I've just merged it and pushed it to the -next branch.
Thank you Thomas! Willy
Hi, Willy
On Wed, Aug 30, 2023 at 05:07:11PM +0200, Thomas Wei�schuh wrote:
This was prompted by the discussion about output directory support with O=. It seems sometimes we were pulling in system headers making testing annoying and unreliable.
Willy:
I did not implement the '#ifdef va_start` guard that we discussed before. In my understanding the latest agreement does not need it anymore. Please let me know if this is incorrect.
No that's fine given your goal of including just "nolibc.h" and no other regular include file, I agree. I've just merged it and pushed it to the -next branch.
Thank you Thomas! Willy
Subject: [PATCH v2 1/2] tools/nolibc: add stdarg.h header
This allows nolic to work with `-nostdinc` avoiding any reliance on system headers.
A little typo in above commit message: nolic -> nolibc.
Thanks, Zhangjin
The implementation has been lifted from musl libc 1.2.4. There is already an implementation of stdarg.h in include/linux/stdarg.h but that is GPL licensed and therefore not suitable for nolibc.
The used compiler builtins have been validated to be at least available since GCC 4.1.2 and clang 3.0.0.
On Thu, Aug 31, 2023 at 12:12:02PM +0800, Zhangjin Wu wrote:
Subject: [PATCH v2 1/2] tools/nolibc: add stdarg.h header
This allows nolic to work with `-nostdinc` avoiding any reliance on system headers.
A little typo in above commit message: nolic -> nolibc.
Yeah I noticed and forgot to fix it. Will probably do it next time I have the opportunity to touch that branch ;-)
Willy
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Thomas Weißschuh -
Willy Tarreau -
Zhangjin Wu