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Diffstat (limited to 'iconv/skeleton.c')
| -rw-r--r-- | iconv/skeleton.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/iconv/skeleton.c b/iconv/skeleton.c new file mode 100644 index 0000000..3582f14 --- /dev/null +++ b/iconv/skeleton.c @@ -0,0 +1,328 @@ +/* Skeleton for a converison module. + Copyright (C) 1998 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* This file can be included to provide definitions of several things + many modules have in common. It can be customized using the following + macros: + + DEFINE_INIT define the default initializer. This requires the + following symbol to be defined. + + CHARSET_NAME string with official name of the coded character + set (in all-caps) + + DEFINE_FINI define the default destructor function. + + MIN_NEEDED_FROM minimal number of bytes needed for the from-charset. + MIN_NEEDED_TO likewise for the to-charset. + + MAX_NEEDED_FROM maximal number of bytes needed for the from-charset. + This macro is optional, it defaults to MIN_NEEDED_FROM. + MAX_NEEDED_TO likewise for the to-charset. + + DEFINE_DIRECTION_OBJECTS + two objects will be defined to be used when the + `gconv' function must only distinguish two + directions. This is implied by DEFINE_INIT. + If this macro is not defined the following + macro must be available. + + FROM_DIRECTION this macro is supposed to return a value != 0 + if we convert from the current character set, + otherwise it return 0. + + EMIT_SHIFT_TO_INIT this symbol is optional. If it is defined it + defines some code which writes out a sequence + of characters which bring the current state into + the initial state. + + FROM_LOOP name of the function implementing the conversion + from the current characters. + TO_LOOP likewise for the other direction + + RESET_STATE in case of an error we must reset the state for + the rerun so this macro must be defined for + stateful encodings. It takes an argument which + is nonzero when saving. + + RESET_INPUT_BUFFER If the input character sets allow this the macro + can be defined to reset the input buffer pointers + to cover only those characters up to the error. + + FUNCTION_NAME if not set the conversion function is named `gconv'. + */ + +#include <assert.h> +#include <gconv.h> +#include <string.h> +#define __need_size_t +#define __need_NULL +#include <stddef.h> + + +/* The direction objects. */ +#if DEFINE_DIRECTION_OBJECTS || DEFINE_INIT +static int from_object; +static int to_object; + +# ifndef FROM_DIRECTION +# define FROM_DIRECTION step->data == &from_object +# endif +#else +# ifndef FROM_DIRECTION +# error "FROM_DIRECTION must be provided if direction objects are not used" +# endif +#endif + + +/* How many bytes are needed at most for the from-charset. */ +#ifndef MAX_NEEDED_FROM +# define MAX_NEEDED_FROM MIN_NEEDED_FROM +#endif + +/* Same for the to-charset. */ +#ifndef MAX_NEEDED_TO +# define MAX_NEEDED_TO MIN_NEEDED_TO +#endif + + +/* For conversions from a fixed width character sets to another fixed width + character set we we can define RESET_INPUT_BUFFER is necessary. */ +#if !defined RESET_INPUT_BUFFER && !defined SAVE_RESET_STATE +# if MIN_NEEDED_FROM == MAX_NEEDED_FROM && MIN_NEEDED_TO == MAX_NEEDED_TO +/* We have to used these `if's here since the compiler cannot know that + (outbuf - outerr) is always divisible by MIN_NEEDED_TO. */ +# define RESET_INPUT_BUFFER \ + if (MIN_NEEDED_FROM % MIN_NEEDED_TO == 0) \ + *inbuf -= (outbuf - outerr) * (MIN_NEEDED_FROM / MIN_NEEDED_TO); \ + else if (MIN_NEEDED_TO % MIN_NEEDED_FROM == 0) \ + *inbuf -= (outbuf - outerr) / (MIN_NEEDED_TO / MIN_NEEDED_FROM); \ + else \ + *inbuf -= ((outbuf - outerr) / MIN_NEEDED_TO) * MIN_NEEDED_FROM +# endif +#endif + + +/* The default init function. It simply matches the name and initializes + the step data to point to one of the objects above. */ +#if DEFINE_INIT +# ifndef CHARSET_NAME +# error "CHARSET_NAME not defined" +# endif + +int +gconv_init (struct gconv_step *step) +{ + /* Determine which direction. */ + if (__strcasestr (step->from_name, CHARSET_NAME) != NULL) + step->data = &from_object; + else if (__strcasestr (step->to_name, CHARSET_NAME) != NULL) + step->data = &to_object; + else + return GCONV_NOCONV; + + step->min_needed_from = MIN_NEEDED_FROM; + step->max_needed_from = MAX_NEEDED_FROM; + step->min_needed_to = MIN_NEEDED_TO; + step->max_needed_to = MAX_NEEDED_TO; + + return GCONV_OK; +} +#endif + + +/* The default destructor function does nothing in the moment and so + be define it at all. But we still provide the macro just in case + we need it some day. */ +#if DEFINE_FINI +#endif + + +/* This is the actual conversion function. */ +#ifndef FUNCTION_NAME +# define FUNCTION_NAME gconv +#endif + +int +FUNCTION_NAME (struct gconv_step *step, struct gconv_step_data *data, + const char **inbuf, const char *inbufend, size_t *written, + int do_flush) +{ + struct gconv_step *next_step = step + 1; + struct gconv_step_data *next_data = data + 1; + gconv_fct fct = next_step->fct; + int status; + + /* If the function is called with no input this means we have to reset + to the initial state. The possibly partly converted input is + dropped. */ + if (do_flush) + { + /* Call the steps down the chain if there are any. */ + if (data->is_last) + status = GCONV_OK; + else + { +#ifdef EMIT_SHIFT_TO_INIT + status = GCONV_OK; + + EMIT_SHIFT_TO_INIT; + + if (status == GCONV_OK) +#endif + /* Give the modules below the same chance. */ + status = (*fct) (next_step, next_data, NULL, NULL, written, 1); + } + } + else + { + /* This variable is used to count the number of characters we + actually converted. */ + size_t converted = 0; + + /* We preserve the initial values of the pointer variables. */ + const char *inptr = *inbuf; + char *outbuf = data->outbuf; + char *outend = data->outbufend; + char *outptr; + + do + { + /* Remember the start value for this round. */ + inptr = *inbuf; + /* The outbuf buffer is empty. */ + outptr = outbuf; + + /* Save the state. */ +#ifdef SAVE_RESET_STATE + SAVE_RESET_STATE (1); +#endif + + if (FROM_DIRECTION) + /* Run the conversion loop. */ + status = FROM_LOOP ((const unsigned char **) inbuf, + (const unsigned char *) inbufend, + (unsigned char **) &outbuf, + (unsigned char *) outend, + data->statep, step->data, &converted); + else + /* Run the conversion loop. */ + status = TO_LOOP ((const unsigned char **) inbuf, + (const unsigned char *) inbufend, + (unsigned char **) &outbuf, + (unsigned char *) outend, + data->statep, step->data, &converted); + + /* If this is the last step leave the loop, there is nothgin + we can do. */ + if (data->is_last) + { + /* Store information about how many bytes are available. */ + data->outbuf = outbuf; + break; + } + + /* Write out all output which was produced. */ + if (outbuf > outptr) + { + const char *outerr = outbuf; + int result; + + result = (*fct) (next_step, next_data, &outerr, outbuf, + written, 0); + + if (result != GCONV_EMPTY_INPUT) + { + if (outerr != outbuf) + { +#ifdef RESET_INPUT_BUFFER + RESET_INPUT_BUFFER; +#else + /* We have a problem with the in on of the functions + below. Undo the conversion upto the error point. */ + size_t nstatus; + + /* Reload the pointers. */ + *inbuf = inptr; + outbuf = outptr; + + /* Reset the state. */ +# ifdef SAVE_RESET_STATE + SAVE_RESET_STATE (0); +# endif + + if (FROM_DIRECTION) + /* Run the conversion loop. */ + nstatus = FROM_LOOP ((const unsigned char **) inbuf, + (const unsigned char *) inbufend, + (unsigned char **) &outbuf, + (unsigned char *) outerr, + data->statep, step->data, + &converted); + else + /* Run the conversion loop. */ + nstatus = TO_LOOP ((const unsigned char **) inbuf, + (const unsigned char *) inbufend, + (unsigned char **) &outbuf, + (unsigned char *) outerr, + data->statep, step->data, + &converted); + + /* We must run out of output buffer space in this + rerun. */ + assert (nstatus == GCONV_FULL_OUTPUT + && outbuf == outerr); +#endif /* reset input buffer */ + } + + /* Change the status. */ + status = result; + } + else + /* All the output is consumed, we can make another run + if everything was ok. */ + if (status == GCONV_FULL_OUTPUT) + status = GCONV_OK; + } + } + while (status == GCONV_OK); + + /* Remember how many characters we converted. */ + *written += converted; + } + + return status; +} + +#undef DEFINE_INIT +#undef CHARSET_NAME +#undef DEFINE_FINI +#undef MIN_NEEDED_FROM +#undef MIN_NEEDED_TO +#undef MAX_NEEDED_FROM +#undef MAX_NEEDED_TO +#undef DEFINE_DIRECTION_OBJECTS +#undef FROM_DIRECTION +#undef EMIT_SHIFT_TO_INIT +#undef FROM_LOOP +#undef TO_LOOP +#undef RESET_STATE +#undef RESET_INPUT_BUFFER +#undef FUNCTION_NAME |