if_control.c

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/***************************************************************************
 *   Copyright (C) 2004, 2006 Symbian Software Ltd.                        *
 *   All rights reserved.                                                  *
 *   Copyright (C) 2002, 2003 Tony Finch <dot@dotat.at>.                   *
 *   All rights reserved.                                                  *
 *   Copyright (C) 1985, 1993 The Regents of the University of California. *
 *   All rights reserved.                                                  *
 *                                                                         *
 *   Contributed by Mike Kinghan, imk@strudl.org, derived from the code    *
 *   of Tony Finch                                                         *
 *                                                                         *
 *   Redistribution and use in source and binary forms, with or without    *
 *   modification, are permitted provided that the following conditions    *
 *   are met:                                                              *
 *                                                                         *
 *   Redistributions of source code must retain the above copyright        *
 *   notice, this list of conditions and the following disclaimer.         *
 *                                                                         *
 *   Redistributions in binary form must reproduce the above copyright     *
 *   notice, this list of conditions and the following disclaimer in the   *
 *   documentation and/or other materials provided with the distribution.  *
 *                                                                         *
 *   Neither the name of Symbian Software Ltd. nor the names of its        *
 *   contributors may be used to endorse or promote products derived from  *
 *   this software without specific prior written permission.              *
 *                                                                         *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS   *
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT     *
 *   LIMITED TO, THE IMPLIED WARRANTIES OF  MERCHANTABILITY AND FITNESS    *
 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE        *
 *   COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,   *
 *   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,  *
 *   BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS *
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 *   AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,*
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 **************************************************************************/

#include "if_control.h"
#include "report.h"
#include "line_edit.h"
#include "line_despatch.h"
#include "chew.h"
#include "io.h"



#define MAXDEPTH        64

/* Helpers ****************************************************************/

typedef void transition_t(void);

static void
done_file(void);

static void
nest(void);

static void
set_state(if_state_t is);

static void Strue (void)
{
    drop();
    set_state(IF_STATE_TRUE_PREFIX);
}
static void Sfalse(void)
{
    drop();
    set_state(IF_STATE_FALSE_PREFIX);
}
static void Selse (void)
{
    drop();
    set_state(IF_STATE_TRUE_ELSE);
}
static void Pelif (void)
{
    print();
    set_state(IF_STATE_PASS_MIDDLE);
}
static void Pelse (void)
{
    print();
    set_state(IF_STATE_PASS_ELSE);
}
static void Pendif(void);
static void Dfalse(void)
{
    drop();
    set_state(IF_STATE_FALSE_TRAILER);
}
static void Delif (void)
{
    drop();
    set_state(IF_STATE_FALSE_MIDDLE);
}
static void Delse (void)
{
    drop();
    set_state(IF_STATE_FALSE_ELSE);
}
static void Dendif(void);
static void Fdrop (void)
{
    nest();
    Dfalse();
}
static void Fpass (void)
{
    nest();
    Pelif();
}
static void Ftrue (void)
{
    nest();
    Strue();
}
static void Ffalse(void)
{
    nest();
    Sfalse();
}
static void Mpass (void)
{
    strncpy(GET_PUBLIC(line_edit,keyword), "if  ", 4);
    Pelif();
}
static void Mtrue (void)
{
    keywordedit("else\n");
    set_state(IF_STATE_TRUE_MIDDLE);
}
static void Melif (void)
{
    keywordedit("endif\n");
    set_state(IF_STATE_FALSE_TRAILER);
}
static void Melse (void)
{
    keywordedit("endif\n");
    set_state(IF_STATE_FALSE_ELSE);
}

static transition_t * const
transition_table[IF_STATE_COUNT][LT_SENTINEL] = {
    /* IF_STATE_OUTSIDE*/
    {
        Fpass,
        Ftrue,
        Ffalse,
        orphan_elif,
        orphan_elif,
        orphan_elif,
        orphan_else,
        orphan_endif,
        print,
        done_file
    },
    /* IF_STATE_FALSE_PREFIX*/
    {
        Fdrop,
        Fdrop,
        Fdrop,
        Mpass,
        Strue,
        Sfalse,
        Selse,
        Dendif,
        drop,
        early_eof
    },
    /* IF_STATE_TRUE_PREFIX*/
    {
        Fpass,
        Ftrue,
        Ffalse,
        Dfalse,
        Dfalse,
        Dfalse,
        Delse,
        Dendif,
        print,
        early_eof
    },
    /* IF_STATE_PASS_MIDDLE*/
    {
        Fpass,
        Ftrue,
        Ffalse,
        Pelif,
        Mtrue,
        Delif,
        Pelse,
        Pendif,
        print,
        early_eof
    },
    /* IF_STATE_FALSE_MIDDLE*/
    {
        Fdrop,
        Fdrop,
        Fdrop,
        Pelif,
        Mtrue,
        Delif,
        Pelse,
        Pendif,
        drop,
        early_eof
    },
    /* IF_STATE_TRUE_MIDDLE*/
    {
        Fpass,
        Ftrue,
        Ffalse,
        Melif,
        Melif,
        Melif,
        Melse,
        Pendif,
        print,
        early_eof
    },
    /* IF_STATE_PASS_ELSE*/
    {
        Fpass,
        Ftrue,
        Ffalse,
        orphan_elif,
        orphan_elif,
        orphan_elif,
        orphan_else,
        Pendif,
        print,
        early_eof
    },
    /* IF_STATE_FALSE_ELSE*/
    {
        Fdrop,
        Fdrop,
        Fdrop,
        orphan_elif,
        orphan_elif,
        orphan_elif,
        orphan_else,
        Dendif,
        drop,
        early_eof
    },
    /* IF_STATE_TRUE_ELSE*/
    {
        Fpass,
        Ftrue,
        Ffalse,
        orphan_elif,
        orphan_elif,
        orphan_elif,
        orphan_else,
        Dendif,
        print,
        early_eof
    },
    /* IF_STATE_FALSE_TRAILER*/
    {
        Fdrop,
        Fdrop,
        Fdrop,
        Dfalse,
        Dfalse,
        Dfalse,
        Delse,
        Dendif,
        drop,
        early_eof
    }
    /*IF     TRUE   FALSE  ELIF   ELTRUE ELFALSE ELSE  ENDIF  PLAIN  EOF*/
};


STATE_DEF(if_control)
{
    if_state_t  ifstate[MAXDEPTH];
    size_t              depth;
    size_t              if_start_lines[MAXDEPTH];
}
STATE_T(if_control);


NO_PUBLIC_STATE(if_control);

IMPLEMENT(if_control,ZERO_INITABLE);

static void
done_file(void)
{
    if (GET_PUBLIC(chew,comment_state) != NO_COMMENT) {
        parse_error(GRIPE_EOF_IN_COMMENT,
                    "EOF in comment, #error ... or #define ... commencing line %d",
                    GET_PUBLIC(chew,last_comment_start_line));
    }
    if (GET_PUBLIC(chew,in_double_quote)) {
        parse_error(GRIPE_EOF_IN_QUOTE,
                    "EOF in quotation commencing line %d",
                    GET_PUBLIC(chew,last_quote_start_line));
    }
}

static void
nest(void)
{
    size_t deep = ++SET_STATE(if_control,depth);
    if (deep >= MAXDEPTH) {
        bail(GRIPE_TOO_DEEP,"Too many levels of nesting");
    }
    GET_STATE(if_control,if_start_lines)[deep] = GET_PUBLIC(io,line_num);
}

static void
set_state(if_state_t is)
{
    size_t deep = if_depth();
    GET_STATE(if_control,ifstate)[deep] = is;
}

static void Pendif(void)
{
    print();
    --SET_STATE(if_control,depth);
}

static void Dendif(void)
{
    drop();
    --SET_STATE(if_control,depth);
}

/* API ********************************************************************/

void
transition(line_type_t linetype)
{
    if_state_t state = GET_STATE(if_control,ifstate)[if_depth()];
    transition_table[state][linetype]();
}

bool
dead_line(void)
{
    if_state_t state =
        GET_STATE(if_control,ifstate)[if_depth()];
    return state == IF_STATE_FALSE_PREFIX ||
           state == IF_STATE_FALSE_MIDDLE ||
           state == IF_STATE_FALSE_ELSE ||
           state == IF_STATE_FALSE_TRAILER;
}

bool
was_unconditional_line(void)
{
    return
        GET_STATE(if_control,ifstate)[if_depth()] ==
        IF_STATE_OUTSIDE;
}

bool
is_unconditional_line(void)
{
    if_state_t state =
        GET_STATE(if_control,ifstate)[if_depth()];
    return      state == IF_STATE_OUTSIDE ||
            state == IF_STATE_TRUE_PREFIX ||
            state == IF_STATE_TRUE_MIDDLE ||
            state == IF_STATE_TRUE_ELSE ;
}

if_state_t
if_state(void)
{
    return GET_STATE(if_control,ifstate)[if_depth()];
}

size_t
if_depth(void)
{
    return GET_STATE(if_control,depth);
}

size_t
if_start_line(void)
{
    return GET_STATE(if_control,if_start_lines)[if_depth()];
}

void
if_control_toplevel(void)
{
    SET_STATE(if_control,depth) = 0;
}


/* EOF*/