tcc.c

tcc

            } else if (c == '\\') {
                /* escape : just skip \[\r]\n */
                PEEKC_EOB(c, p);
                if (c == '\n') {
                    file->line_num++;
                    p++;
                } else if (c == '\r') {
                    PEEKC_EOB(c, p);
                    if (c != '\n')
                        expect("'\n' after '\r'");
                    file->line_num++;
                    p++;
                } else if (c == CH_EOF) {
                    goto unterminated_string;
                } else {
                    if (str) {
                        cstr_ccat(str, '\\');
                        cstr_ccat(str, c);
                    }
                    p++;
                }
            }
        } else if (c == '\n') {
            file->line_num++;
            goto add_char;
        } else if (c == '\r') {
            PEEKC_EOB(c, p);
            if (c != '\n') {
                cstr_ccat(str, '\r');
            } else {
                file->line_num++;
                goto add_char;
            }
        } else {
        add_char:
            if (str)
                cstr_ccat(str, c);
            p++;
        }
    }
    p++;
    return p;
}

/* skip block of text until #else, #elif or #endif. skip also pairs of
   #if/#endif */
void preprocess_skip(void)
{
    int a, start_of_line, c;
    uint8_t *p;

    p = file->buf_ptr;
    start_of_line = 1;
    a = 0;
    for(;;) {
    redo_no_start:
        c = *p;
        switch(c) {
        case ' ':
        case '\t':
        case '\f':
        case '\v':
        case '\r':
            p++;
            goto redo_no_start;
        case '\n':
            start_of_line = 1;
            file->line_num++;
            p++;
            goto redo_no_start;
        case '\\':
            file->buf_ptr = p;
            c = handle_eob();
            if (c == CH_EOF) {
                expect("#endif");
            } else if (c == '\\') {
                /* XXX: incorrect: should not give an error */
                ch = file->buf_ptr[0];
                handle_stray();
            }
            p = file->buf_ptr;
            goto redo_no_start;
            /* skip strings */
        case '\"':
        case '\'':
            p = parse_pp_string(p, c, NULL);
            break;
            /* skip comments */
        case '/':
            file->buf_ptr = p;
            ch = *p;
            minp();
            p = file->buf_ptr;
            if (ch == '*') {
                p = parse_comment(p);
            } else if (ch == '/') {
                p = parse_line_comment(p);
            }
            break;

        case '#':
            p++;
            if (start_of_line) {
                file->buf_ptr = p;
                next_nomacro();
                p = file->buf_ptr;
                if (a == 0 && 
                    (tok == TOK_ELSE || tok == TOK_ELIF || tok == TOK_ENDIF))
                    goto the_end;
                if (tok == TOK_IF || tok == TOK_IFDEF || tok == TOK_IFNDEF)
                    a++;
                else if (tok == TOK_ENDIF)
                    a--;
            }
            break;
        default:
            p++;
            break;
        }
        start_of_line = 0;
    }
 the_end: ;
    file->buf_ptr = p;
}

/* ParseState handling */

/* XXX: currently, no include file info is stored. Thus, we cannot display
   accurate messages if the function or data definition spans multiple
   files */

/* save current parse state in 's' */
void save_parse_state(ParseState *s)
{
    s->line_num = file->line_num;
    s->macro_ptr = macro_ptr;
    s->tok = tok;
    s->tokc = tokc;
}

/* restore parse state from 's' */
void restore_parse_state(ParseState *s)
{
    file->line_num = s->line_num;
    macro_ptr = s->macro_ptr;
    tok = s->tok;
    tokc = s->tokc;
}

/* return the number of additional 'ints' necessary to store the
   token */
static inline int tok_ext_size(int t)
{
    switch(t) {
        /* 4 bytes */
    case TOK_CINT:
    case TOK_CUINT:
    case TOK_CCHAR:
    case TOK_LCHAR:
    case TOK_STR:
    case TOK_LSTR:
    case TOK_CFLOAT:
    case TOK_LINENUM:
    case TOK_PPNUM:
        return 1;
    case TOK_CDOUBLE:
    case TOK_CLLONG:
    case TOK_CULLONG:
        return 2;
    case TOK_CLDOUBLE:
        return LDOUBLE_SIZE / 4;
    default:
        return 0;
    }
}

/* token string handling */

static inline void tok_str_new(TokenString *s)
{
    s->str = NULL;
    s->len = 0;
    s->allocated_len = 0;
    s->last_line_num = -1;
}

static void tok_str_free(int *str)
{
    const int *p;
    CString *cstr;
    int t;

    p = str;
    for(;;) {
        t = *p;
        /* NOTE: we test zero separately so that GCC can generate a
           table for the following switch */
        if (t == 0)
            break;
        switch(t) {
        case TOK_CINT:
        case TOK_CUINT:
        case TOK_CCHAR:
        case TOK_LCHAR:
        case TOK_CFLOAT:
        case TOK_LINENUM:
            p += 2;
            break;
        case TOK_PPNUM:
        case TOK_STR:
        case TOK_LSTR:
            /* XXX: use a macro to be portable on 64 bit ? */
            cstr = (CString *)p[1];
            cstr_free(cstr);
            tcc_free(cstr);
            p += 2;
            break;
        case TOK_CDOUBLE:
        case TOK_CLLONG:
        case TOK_CULLONG:
            p += 3;
            break;
        case TOK_CLDOUBLE:
            p += 1 + (LDOUBLE_SIZE / 4);
            break;
        default:
            p++;
            break;
        }
    }
    tcc_free(str);
}

static int *tok_str_realloc(TokenString *s)
{
    int *str, len;

    len = s->allocated_len + TOK_STR_ALLOC_INCR;
    str = tcc_realloc(s->str, len * sizeof(int));
    if (!str)
        error("memory full");
    s->allocated_len = len;
    s->str = str;
    return str;
}

static void tok_str_add(TokenString *s, int t)
{
    int len, *str;

    len = s->len;
    str = s->str;
    if (len >= s->allocated_len)
        str = tok_str_realloc(s);
    str[len++] = t;
    s->len = len;
}

static void tok_str_add2(TokenString *s, int t, CValue *cv)
{
    int len, *str;

    len = s->len;
    str = s->str;

    /* allocate space for worst case */
    if (len + TOK_MAX_SIZE > s->allocated_len)
        str = tok_str_realloc(s);
    str[len++] = t;
    switch(t) {
    case TOK_CINT:
    case TOK_CUINT:
    case TOK_CCHAR:
    case TOK_LCHAR:
    case TOK_CFLOAT:
    case TOK_LINENUM:
        str[len++] = cv->tab[0];
        break;
    case TOK_PPNUM:
    case TOK_STR:
    case TOK_LSTR:
        str[len++] = (int)cstr_dup(cv->cstr);
        break;
    case TOK_CDOUBLE:
    case TOK_CLLONG:
    case TOK_CULLONG:
        str[len++] = cv->tab[0];
        str[len++] = cv->tab[1];
        break;
    case TOK_CLDOUBLE:
#if LDOUBLE_SIZE == 12
        str[len++] = cv->tab[0];
        str[len++] = cv->tab[1];
        str[len++] = cv->tab[2];
#else
#error add long double size support
#endif
        break;
    default:
        break;
    }
    s->len = len;
}

/* add the current parse token in token string 's' */
static void tok_str_add_tok(TokenString *s)
{
    CValue cval;

    /* save line number info */
    if (file->line_num != s->last_line_num) {
        s->last_line_num = file->line_num;
        cval.i = s->last_line_num;
        tok_str_add2(s, TOK_LINENUM, &cval);
    }
    tok_str_add2(s, tok, &tokc);
}

#if LDOUBLE_SIZE == 12
#define LDOUBLE_GET(p, cv)                      \
        cv.tab[0] = p[0];                       \
        cv.tab[1] = p[1];                       \
        cv.tab[2] = p[2];
#else
#error add long double size support
#endif


/* get a token from an integer array and increment pointer
   accordingly. we code it as a macro to avoid pointer aliasing. */
#define TOK_GET(t, p, cv)                       \
{                                               \
    t = *p++;                                   \
    switch(t) {                                 \
    case TOK_CINT:                              \
    case TOK_CUINT:                             \
    case TOK_CCHAR:                             \
    case TOK_LCHAR:                             \
    case TOK_CFLOAT:                            \
    case TOK_LINENUM:                           \
    case TOK_STR:                               \
    case TOK_LSTR:                              \
    case TOK_PPNUM:                             \
        cv.tab[0] = *p++;                       \
        break;                                  \
    case TOK_CDOUBLE:                           \
    case TOK_CLLONG:                            \
    case TOK_CULLONG:                           \
        cv.tab[0] = p[0];                       \
        cv.tab[1] = p[1];                       \
        p += 2;                                 \
        break;                                  \
    case TOK_CLDOUBLE:                          \
        LDOUBLE_GET(p, cv);                     \
        p += LDOUBLE_SIZE / 4;                  \
        break;                                  \
    default:                                    \
        break;                                  \
    }                                           \
}

/* defines handling */
static inline void define_push(int v, int macro_type, int *str, Sym *first_arg)
{
    Sym *s;

    s = sym_push2(&define_stack, v, macro_type, (int)str);
    s->next = first_arg;
    table_ident[v - TOK_IDENT]->sym_define = s;
}

/* undefined a define symbol. Its name is just set to zero */
static void define_undef(Sym *s)
{
    int v;
    v = s->v;
    if (v >= TOK_IDENT && v < tok_ident)
        table_ident[v - TOK_IDENT]->sym_define = NULL;
    s->v = 0;
}

static inline Sym *define_find(int v)
{
    v -= TOK_IDENT;
    if ((unsigned)v >= (unsigned)(tok_ident - TOK_IDENT))
        return NULL;
    return table_ident[v]->sym_define;
}

/* free define stack until top reaches 'b' */
static void free_defines(Sym *b)
{
    Sym *top, *top1;
    int v;

    top = define_stack;
    while (top != b) {
        top1 = top->prev;
        /* do not free args or predefined defines */
        if (top->c)
            tok_str_free((int *)top->c);
        v = top->v;
        if (v >= TOK_IDENT && v < tok_ident)
            table_ident[v - TOK_IDENT]->sym_define = NULL;
        tcc_free(top);
        top = top1;
    }
    define_stack = b;
}

/* label lookup */
static Sym *label_find(int v)
{
    v -= TOK_IDENT;
    if ((unsigned)v >= (unsigned)(tok_ident - TOK_IDENT))
        return NULL;
    return table_ident[v]->sym_label;
}

static Sym *label_push(Sym **ptop, int v, int flags)
{
    Sym *s, **ps;
    s = sym_push2(ptop, v, 0, 0);
    s->r = flags;
    ps = &table_ident[v - TOK_IDENT]->sym_label;
    if (ptop == &global_label_stack) {
        /* modify the top most local identifier, so that
           sym_identifier will point to 's' when popped */
        while (*ps != NULL)
            ps = &(*ps)->prev_tok;
    }
    s->prev_tok = *ps;
    *ps = s;
    return s;
}

/* pop labels until element last is reached. Look if any labels are
   undefined. Define symbols if '&&label' was used. */
static void label_pop(Sym **ptop, Sym *slast)
{
    Sym *s, *s1;
    for(s = *ptop; s != slast; s = s1) {
        s1 = s->prev;
        if (s->r == LABEL_DECLARED) {
            warning("label '%s' declared but not used", get_tok_str(s->v, NULL));
        } else if (s->r == LABEL_FORWARD) {
                error("label '%s' used but not defined",
                      get_tok_str(s->v, NULL));
        } else {
            if (s->c) {
                /* define corresponding symbol. A size of
                   1 is put. */
                put_extern_sym(s, cur_text_section, (long)s->next, 1);
            }
        }
        /* remove label */
        table_ident[s->v - TOK_IDENT]->sym_label = s->prev_tok;
        tcc_free(s);
    }
    *ptop = slast;
}

/* eval an expression for #if/#elif */
static int expr_preprocess(void)
{
    int c, t;
    TokenString str;
    
    tok_str_new(&str);
    while (tok != TOK_LINEFEED && tok != TOK_EOF) {
        next(); /* do macro subst */
        if (tok == TOK_DEFINED) {
            next_nomacro();
            t = tok;
            if (t == '(') 
                next_nomacro();
            c = define_find(tok) != 0;
            if (t == '(')
                next_nomacro();
            tok = TOK_C