linux-toradex.git/tools/include/nolibc/stdio.h, branch v6.9-rc4

tools/nolibc: annotate va_list printf formats

2023-12-11T21:38:32+00:00

__attribute__(format(printf)) can also be used for functions that take a
va_list argument.

As per the GCC docs:

    For functions where the arguments are not available to be checked
    (such as vprintf), specify the third parameter as zero.

Link: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html
Signed-off-by: Thomas Weißschuh

tools/nolibc: add stdarg.h header

2023-10-12T19:13:52+00:00

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 
Signed-off-by: Willy Tarreau

tools/nolibc: setvbuf: avoid unused parameter warnings

2023-08-23T03:17:07+00:00

This warning will be enabled later so avoid triggering it.

Signed-off-by: Thomas Weißschuh 
Signed-off-by: Willy Tarreau

tools/nolibc/stdio: add setvbuf() to set buffering mode

2023-08-23T02:40:22+00:00

Add a minimal implementation of setvbuf(), which error checks the mode
argument (as required by spec) and returns. Since nolibc never buffers
output, nothing needs to be done.

The kselftest framework recently added a call to setvbuf(). As a result,
any tests that use the kselftest framework and nolibc cause a compiler
error due to missing function. This provides an urgent fix for the
problem which is preventing arm64 testing on linux-next.

Example:

clang --target=aarch64-linux-gnu -fintegrated-as
-Werror=unknown-warning-option -Werror=ignored-optimization-argument
-Werror=option-ignored -Werror=unused-command-line-argument
--target=aarch64-linux-gnu -fintegrated-as
-fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \
-include ../../../../include/nolibc/nolibc.h -I../..\
-static -ffreestanding -Wall za-fork.c
build/kselftest/arm64/fp/za-fork-asm.o
-o build/kselftest/arm64/fp/za-fork
In file included from :1:
In file included from ./../../../../include/nolibc/nolibc.h:97:
In file included from ./../../../../include/nolibc/arch.h:25:
./../../../../include/nolibc/arch-aarch64.h:178:35: warning: unknown
attribute 'optimize' ignored [-Wunknown-attributes]
void __attribute__((weak,noreturn,optimize("omit-frame-pointer")))
__no_stack_protector _start(void)
                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from za-fork.c:12:
../../kselftest.h:123:2: error: call to undeclared function 'setvbuf';
ISO C99 and later do not support implicit function declarations
[-Wimplicit-function-declaration]
        setvbuf(stdout, NULL, _IOLBF, 0);
        ^
../../kselftest.h:123:24: error: use of undeclared identifier '_IOLBF'
        setvbuf(stdout, NULL, _IOLBF, 0);
                              ^
1 warning and 2 errors generated.

Signed-off-by: Ryan Roberts 
Reported-by: Linux Kernel Functional Testing 
Link: https://lore.kernel.org/linux-kselftest/CA+G9fYus3Z8r2cg3zLv8uH8MRrzLFVWdnor02SNr=rCz+_WGVg@mail.gmail.com/
Reviewed-by: Mark Brown 
Signed-off-by: Willy Tarreau

tools/nolibc: implement fd-based FILE streams

2023-06-09T18:33:05+00:00

This enables the usage of the stream APIs with arbitrary filedescriptors.

It will be used by a future testcase.

Signed-off-by: Thomas Weißschuh 
Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney

tools/nolibc/stdio: Implement vprintf()

2023-04-11T20:10:42+00:00

vprintf() is equivalent to vfprintf() to stdout so implement it as a simple
wrapper for the existing vfprintf(), allowing us to build kselftest.h.

Suggested-by: Willy Tarreau 
Signed-off-by: Mark Brown 
Acked-by: Willy Tarreau 
Acked-by: Paul E. McKenney 
Acked-by: Shuah Khan 
Signed-off-by: Shuah Khan

tools/nolibc: fix missing includes causing build issues at -O0

2023-01-09T17:36:05+00:00

After the nolibc includes were split to facilitate portability from
standard libcs, programs that include only what they need may miss
some symbols which are needed by libgcc. This is the case for raise()
which is needed by the divide by zero code in some architectures for
example.

Regardless, being able to include only the apparently needed files is
convenient.

Instead of trying to move all exported definitions to a single file,
since this can change over time, this patch takes another approach
consisting in including the nolibc header at the end of all standard
include files. This way their types and functions are already known
at the moment of inclusion, and including any single one of them is
sufficient to bring all the required ones.

Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney

tools/nolibc/stdio: Add format attribute to enable printf warnings

2022-06-20T16:43:19+00:00

When we use printf and fprintf functions from the nolibc, we don't
get any warning from the compiler if we have the wrong arguments.
For example, the following calls will compile silently:
```
  printf("%s %s\n", "aaa");
  fprintf(stdout, "%s %s\n", "xxx", 1);
```
(Note the wrong arguments).

Those calls are undefined behavior. The compiler can help us warn
about the above mistakes by adding a `printf` format attribute to
those functions declaration. This patch adds it, and now it yields
these warnings for those mistakes:
```
  warning: format `%s` expects a matching `char *` argument [-Wformat=]
  warning: format `%s` expects argument of type `char *`, but argument 4 has type `int` [-Wformat=]
```

  [ ammarfaizi2: Simplify the attribute placement. ]

Signed-off-by: Alviro Iskandar Setiawan 
Signed-off-by: Ammar Faizi 
Acked-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney

tools/nolibc/stdio: add support for '%p' to vfprintf()

2022-04-21T00:05:45+00:00

%p remains quite useful in test code, and the code path can easily be
merged with the existing "%x" thus only adds ~50 bytes, thus let's
add it.

Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney

tools/nolibc/stdio: make printf(%s) accept NULL

2022-04-21T00:05:45+00:00

It's often convenient to support this, especially in test programs where
a NULL may correspond to an allocation error or a non-existing value.
Let's make printf("%s") support being passed a NULL. In this case it
prints "(null)" like glibc's printf().

Signed-off-by: Willy Tarreau 
Signed-off-by: Paul E. McKenney