[PATCH v5 03/11] stdio-common: Add __printf_function_invoke

[Adhemerval Zanella Netto]

On 12/12/22 12:23, Florian Weimer via Libc-alpha wrote:
> And __wprintf_function_invoke.  These functions will be used to
> to call registered printf specifier callbacks on printf buffers
> after vfprintf and vfwprintf have been converted to buffers.  The new
> implementation avoids alloca/variable length arrays.

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  include/printf.h                       | 10 +++++
>  stdio-common/Makefile                  |  2 +
>  stdio-common/Xprintf_function_invoke.c | 58 ++++++++++++++++++++++++++
>  stdio-common/printf_function_invoke.c  | 22 ++++++++++
>  stdio-common/wprintf_function_invoke.c | 22 ++++++++++
>  5 files changed, 114 insertions(+)
>  create mode 100644 stdio-common/Xprintf_function_invoke.c
>  create mode 100644 stdio-common/printf_function_invoke.c
>  create mode 100644 stdio-common/wprintf_function_invoke.c
> 
> diff --git a/include/printf.h b/include/printf.h
> index 78accaab6d..8f064149d3 100644
> --- a/include/printf.h
> +++ b/include/printf.h
> @@ -41,6 +41,16 @@ union printf_arg
>      void *pa_user;
>  };
>  
> +/* Invoke a registered printf callback.  Called from vfprintf and vfwprintf.  */
> +int __printf_function_invoke (void *, printf_function callback,
> +			      union printf_arg *args_value,
> +			      size_t ndata_args,
> +			      struct printf_info *info) attribute_hidden;
> +int __wprintf_function_invoke (void *, printf_function callback,
> +			       union printf_arg *args_value,
> +			       size_t ndata_args,
> +			       struct printf_info *info) attribute_hidden;
> +
>  #include <bits/types/locale_t.h>
>  
>  /* Now define the internal interfaces.  */

Ok.

> diff --git a/stdio-common/Makefile b/stdio-common/Makefile
> index 120d66ea93..6e6da091b1 100644
> --- a/stdio-common/Makefile
> +++ b/stdio-common/Makefile
> @@ -63,6 +63,7 @@ routines := \
>    printf_buffer_write \
>    printf_fp \
>    printf_fphex \
> +  printf_function_invoke \
>    printf_size \
>    psiginfo \
>    psignal \
> @@ -101,6 +102,7 @@ routines := \
>    wprintf_buffer_puts_1 \
>    wprintf_buffer_to_file \
>    wprintf_buffer_write \
> +  wprintf_function_invoke \
>    # routines
>  
>  aux := \

Ok.

> diff --git a/stdio-common/Xprintf_function_invoke.c b/stdio-common/Xprintf_function_invoke.c
> new file mode 100644
> index 0000000000..908d02bf24
> --- /dev/null
> +++ b/stdio-common/Xprintf_function_invoke.c
> @@ -0,0 +1,58 @@
> +/* Invoke a printf specifier handler.  Generic version.
> +   Copyright (C) 1991-2022 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <array_length.h>
> +
> +int
> +Xprintf (function_invoke) (void *buf,
> +                           printf_function callback,
> +                           union printf_arg *args_value,
> +                           size_t ndata_args,
> +                           struct printf_info *info)
> +{
> +  /* Most custom specifiers expect just one argument.  Use the heap
> +     for larger argument arrays.  */
> +  const void *onstack_args[4];
> +  const void **args;
> +  if (ndata_args <= array_length (onstack_args))
> +    args = onstack_args;
> +  else
> +    {
> +      args = calloc (ndata_args, sizeof (*args));
> +      if (args == NULL)
> +        return -1;
> +    }
> +
> +  for (unsigned int i = 0; i < ndata_args; ++i)
> +    args[i] = &args_value[i];
> +
> +  struct Xprintf (buffer_as_file) s;
> +  Xprintf (buffer_as_file_init) (&s, buf);
> +
> +  /* Call the function.  */
> +  int done = callback (Xprintf (buffer_as_file_get) (&s), info, args);
> +
> +  if (!Xprintf (buffer_as_file_terminate) (&s))
> +    done = -1;
> +
> +  if (args != onstack_args)
> +    free (args);
> +
> +  /* Potential error from the callback function.  */
> +  return done;
> +}

Ok.

> diff --git a/stdio-common/printf_function_invoke.c b/stdio-common/printf_function_invoke.c
> new file mode 100644
> index 0000000000..8919b892ca
> --- /dev/null
> +++ b/stdio-common/printf_function_invoke.c
> @@ -0,0 +1,22 @@
> +/* Invoke a printf specifier handler.  Multibyte version.
> +   Copyright (C) 2022 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <printf.h>
> +#include <printf_buffer_as_file.h>
> +#include "printf_buffer-char.h"
> +#include "Xprintf_function_invoke.c"

Ok.

> diff --git a/stdio-common/wprintf_function_invoke.c b/stdio-common/wprintf_function_invoke.c
> new file mode 100644
> index 0000000000..29a6b4e073
> --- /dev/null
> +++ b/stdio-common/wprintf_function_invoke.c
> @@ -0,0 +1,22 @@
> +/* Invoke a printf specifier handler.  Wide version.
> +   Copyright (C) 2022 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <printf.h>
> +#include <printf_buffer_as_file.h>
> +#include "printf_buffer-wchar_t.h"
> +#include "Xprintf_function_invoke.c"

Ok.