add printf functions, not fully implemented

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 252 insertions, 0 deletions

diff --git a/include/slibc-print.h b/include/slibc-print.h
new file mode 100644
index 0000000..b992537
--- /dev/null
+++ b/include/slibc-print.h
@@ -0,0 +1,252 @@
+/**
+ * slibc — Yet another C library
+ * Copyright © 2015  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef _SLIBC_PRINT_H
+#define _SLIBC_PRINT_H
+#include <slibc/version.h>
+#include <slibc/features.h>
+#ifndef __PORTABLE
+
+
+
+/**
+ * `NULL`'s canonical header is <stddef.h>
+ */
+#ifndef NULL
+# define NULL  ((void*)0)
+#endif
+
+
+#define __NEED_size_t
+#define __NEED_ssize_t
+#define __NEED_wchar_t
+#define __NEED_intmax_t
+#define __NEED_va_list
+#include <bits/types.h>
+
+
+
+/**
+ * Structure used by extensions to `generic_printf`-function
+ * to request that additionally arguments be added before the
+ * function is called again.
+ */
+struct generic_printf_ext_queue
+{
+  /**
+   * Sizes, in bytes, of the missing arguments.
+   * Only 1, 2, 4 and 8 are allowed.
+   */
+  char sizes[4];
+  
+  /**
+   * The indices of the missing arguments.
+   */
+  size_t indices[4];
+  
+  /**
+   * The amount of missing arguments.
+   * `sizes` and `indices` can only hold up to
+   * 4 arguments, the function will be later
+   * again to retrieve information about the
+   * omitted arguments. To avoid a deadlock,
+   * add arguments in the order of their index
+   * if there are more than 4 missing arguments.
+   */
+  size_t count;
+};
+
+
+/**
+ * Function-type used by `generic_printf` and `vgeneric_wprintf`
+ * to write a string.
+ * 
+ * @param   text    The text segment to print, it will only contain
+ *                  a NUL byte if that NUL byte shall be printed.
+ * @param   length  The length of `text`.
+ * @param   data    The value passed to `generic_printf` or
+ *                  `vgeneric_wprintf` via the parameter `data`.
+ * @return          Zero on success, -1 on error. `errno` shall
+ *                  be set on error.
+ */
+typedef int (* generic_printf_write_func_t)(const char*, size_t, void*);
+
+/**
+ * Variant of `generic_printf_write_func_t` used for
+ * `generic_wprintf` and `vgeneric_wprintf`.
+ */
+typedef int (* generic_wprintf_write_func_t)(const wchar_t*, size_t, void*);
+
+/**
+ * Function-type used by `generic_printf` and `vgeneric_wprintf`
+ * to write a string if a custom formatting code was encountered.
+ * 
+ * @param   code        The %-code, excluding the %.
+ * @param   args        Formatting arguments cased to `intmax`.
+ * @param   argn        The number of formatting arguments in `args`.
+ * @param   silent      Non-zero if the function must not perform a write.
+ * @param   data        The value passed to `generic_printf` or
+ *                      `vgeneric_wprintf` via the parameter `data`.
+ * @param   queue_data  Used to send information to the calling function
+ *                      about missing arguments.
+ * @return              The number of written characters, -1 on error.
+ *                      `errno` shall be set on error. -2 shall be returned
+ *                      if argument index equal to or greater than the
+ *                      value of `argn`, if `queue_data` must be set.
+ * 
+ * @throws  EINVAL  If `code` could not be recognised.
+ */
+typedef ssize_t (* generic_printf_ext_func_t)(const char*, intmax_t*, size_t, int, void*,
+					      struct generic_printf_ext_queue*);
+
+/**
+ * Variant of `generic_printf_ext_func_t` used for
+ * `generic_wprintf` and `vgeneric_wprintf`.
+ */
+typedef ssize_t (* generic_wprintf_ext_func_t)(const wchar_t*, intmax_t*, size_t, int, void*,
+					       struct generic_printf_ext_queue*);
+
+
+/**
+ * An almost fully generic `printf`-function.
+ * 
+ * @param   write_function      Function used to write the string. `NULL` if
+ *                              it shall not be printed but only measured.
+ * @param   extension_function  Function used to extend the functions formatting codes.
+ *                              `NULL` if not extensions are to be used.
+ * @param   maximum_length      The maximum amount of bytes to write, including the
+ *                              NUL byte, ignored if `limited_length` is zero.
+ * @param   limited_length      Whether `maximum_length` shall be used.
+ * @param   actual_length       Output parameter for the length of the printed string,
+ *                              this includes any text that was truncated but not the
+ *                              NUL character. Must not be `NULL`.
+ * @param   terminate           Whether a NUL character shall be printed at the end.
+ * @param   data                Data to pass to `write_function` and
+ *                              `extension_function`, it should contain
+ *                              the print-sink, and any state data neccessary
+ *                              since the functions may be called multiple times.
+ * @param   format              The formatting-string, see `fprintf` for details.
+ * @param   ...                 The formatting-arguments.
+ * @return                      Zero on success, -1 on error. On error, `errno`
+ *                              is set to indicate the error.
+ * 
+ * @throws          Any error thrown by `write_function` or `extension_function`.
+ * @throws  EINVAL  `format` contained unsupported formatting codes.
+ */
+int generic_printf(generic_printf_write_func_t, generic_printf_ext_func_t,
+		   size_t, int, size_t* restrict, int, void*, const char*, ...)
+  __GCC_ONLY(__attribute__((nonnull(5, 8), format(slibc_printf, 8, 9), warn_unused_result)));
+
+/**
+ * Variant of `generic_printf` that uses `va_list`
+ * instead of variadic arguments.
+ * 
+ * @param   write_function      Function used to write the string. `NULL` if
+ *                              it shall not be printed but only measured.
+ * @param   extension_function  Function used to extend the functions formatting codes.
+ *                              `NULL` if not extensions are to be used.
+ * @param   maximum_length      The maximum amount of bytes to write, including the
+ *                              NUL byte, ignored if `limited_length` is zero.
+ * @param   limited_length      Whether `maximum_length` shall be used.
+ * @param   actual_length       Output parameter for the length of the printed string,
+ *                              this includes any text that was truncated but not the
+ *                              NUL character. Must not be `NULL`.
+ * @param   terminate           Whether a NUL character shall be printed at the end.
+ * @param   data                Data to pass to `write_function` and
+ *                              `extension_function`, it should contain
+ *                              the print-sink, and any state data neccessary
+ *                              since the functions may be called multiple times.
+ * @param   format              The formatting-string, see `fprintf` for details.
+ * @param   args                The formatting-arguments.
+ * @return                      Zero on success, -1 on error. On error, `errno`
+ *                              is set to indicate the error.
+ * 
+ * @throws          Any error thrown by `write_function` or `extension_function`.
+ * @throws  EINVAL  `format` contained unsupported formatting codes.
+ */
+int vgeneric_printf(generic_printf_write_func_t, generic_printf_ext_func_t,
+		    size_t, int, size_t* restrict, int, void*, const char*, va_list)
+  __GCC_ONLY(__attribute__((nonnull(5, 8), warn_unused_result)));
+
+/**
+ * Variant of `generic_printf` uses `wchar_t` instead of `char`;
+ * 
+ * @param   write_function      Function used to write the string. `NULL` if
+ *                              it shall not be printed but only measured.
+ * @param   extension_function  Function used to extend the functions formatting codes.
+ *                              `NULL` if not extensions are to be used.
+ * @param   maximum_length      The maximum amount of wide characters to write,
+ *                              including the NUL wide character, ignored if
+ *                              `limited_length` is zero.
+ * @param   limited_length      Whether `maximum_length` shall be used.
+ * @param   actual_length       Output parameter for the length of the printed string,
+ *                              this includes any text that was truncated but not the
+ *                              NUL character. Must not be `NULL`.
+ * @param   terminate           Whether a NUL character shall be printed at the end.
+ * @param   data                Data to pass to `write_function` and
+ *                              `extension_function`, it should contain
+ *                              the print-sink, and any state data neccessary
+ *                              since the functions may be called multiple times.
+ * @param   format              The formatting-string, see `fprintf` for details.
+ * @param   ...                 The formatting-arguments.
+ * @return                      Zero on success, -1 on error. On error, `errno`
+ *                              is set to indicate the error.
+ * 
+ * @throws          Any error thrown by `write_function` or `extension_function`.
+ * @throws  EINVAL  `format` contained unsupported formatting codes.
+ */
+int generic_wprintf(generic_wprintf_write_func_t, generic_wprintf_ext_func_t,
+		    size_t, int, size_t* restrict, int, void*, const wchar_t*, ...)
+  __GCC_ONLY(__attribute__((nonnull(5, 8), warn_unused_result)));
+
+/**
+ * Variant of `generic_wprintf` that uses `va_list`
+ * instead of variadic arguments.
+ * 
+ * @param   write_function      Function used to write the string. `NULL` if
+ *                              it shall not be printed but only measured.
+ * @param   extension_function  Function used to extend the functions formatting codes.
+ *                              `NULL` if not extensions are to be used.
+ * @param   maximum_length      The maximum amount of wide characters to write,
+ *                              including the NUL wide character, ignored if
+ *                              `limited_length` is zero.
+ * @param   limited_length      Whether `maximum_length` shall be used.
+ * @param   actual_length       Output parameter for the length of the printed string,
+ *                              this includes any text that was truncated but not the
+ *                              NUL character. Must not be `NULL`.
+ * @param   terminate           Whether a NUL character shall be printed at the end.
+ * @param   data                Data to pass to `write_function` and
+ *                              `extension_function`, it should contain
+ *                              the print-sink, and any state data neccessary
+ *                              since the functions may be called multiple times.
+ * @param   format              The formatting-string, see `fprintf` for details.
+ * @param   ...                 The formatting-arguments.
+ * @return                      Zero on success, -1 on error. On error, `errno`
+ *                              is set to indicate the error.
+ * 
+ * @throws          Any error thrown by `write_function` or `extension_function`.
+ * @throws  EINVAL  `format` contained unsupported formatting codes.
+ */
+int vgeneric_wprintf(generic_wprintf_write_func_t, generic_wprintf_ext_func_t,
+		     size_t, int, size_t* restrict, int, void*, const wchar_t*, va_list)
+  __GCC_ONLY(__attribute__((nonnull(5, 8), warn_unused_result)));
+
+
+
+#endif
+#endif
+