/* 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 , 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'. PREPARE_LOOP optional code preparing the conversion loop. Can contain variable definitions. EXTRA_LOOP_ARGS optional macro specifying extra arguments passed to loop function. */ #include #include #include #define __need_size_t #define __need_NULL #include /* 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; #ifdef RESET_STATE step->stateful = 1; #else step->stateful = 0; #endif 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 /* If no arguments have to passed to the loop function define the macro as empty. */ #ifndef EXTRA_LOOP_ARGS # define EXTRA_LOOP_ARGS #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; size_t last_converted; /* We preserve the initial values of the pointer variables. */ const char *inptr = *inbuf; char *outbuf = data->outbuf; char *outend = data->outbufend; char *outptr; #ifdef PREPARE_LOOP PREPARE_LOOP #endif do { /* Remember the start value for this round. */ inptr = *inbuf; /* The outbuf buffer is empty. */ outptr = outbuf; /* Save the state. */ last_converted = converted; #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 EXTRA_LOOP_ARGS); 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 EXTRA_LOOP_ARGS); /* 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 = data->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. */ converted = last_converted; # 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 EXTRA_LOOP_ARGS); 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 EXTRA_LOOP_ARGS); /* We must run out of output buffer space in this rerun. */ assert (outbuf == outerr); assert (nstatus == GCONV_FULL_OUTPUT); #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