From c7bf2e99cafbd8970f81c38d6f32842cc7846421 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Mon, 19 Dec 2022 18:56:54 +0100 Subject: stdio-common: Add __printf_function_invoke 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. Reviewed-by: Adhemerval Zanella --- stdio-common/Xprintf_function_invoke.c | 58 ++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 stdio-common/Xprintf_function_invoke.c (limited to 'stdio-common/Xprintf_function_invoke.c') diff --git a/stdio-common/Xprintf_function_invoke.c b/stdio-common/Xprintf_function_invoke.c new file mode 100644 index 0000000..908d02b --- /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 + . */ + +#include + +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; +} -- cgit v1.1