nasmlib.c

nasm早期的源代码,比较简单是学习汇编和编译原理的好例子

         * Must add a layer.
         */
        struct RAA *s;
        int i;

        s = nasm_malloc(BRANCHSIZ);
        for (i = 0; i < RAA_LAYERSIZE; i++)
            s->u.b.data[i] = NULL;
        s->layers = r->layers + 1;
        s->stepsize = LAYERSIZ(r) * r->stepsize;
        s->u.b.data[0] = r;
        r = s;
    }

    result = r;

    while (r->layers > 0) {
        ldiv_t l;
        struct RAA **s;
        l = ldiv(posn, r->stepsize);
        s = &r->u.b.data[l.quot];
        if (!*s)
            *s = real_raa_init(r->layers - 1);
        r = *s;
        posn = l.rem;
    }

    r->u.l.data[posn] = value;

    return result;
}

/* Aggregate SAA components smaller than this */
#define SAA_BLKLEN 65536

struct SAA *saa_init(size_t elem_len)
{
    struct SAA *s;
    char *data;

    s = nasm_zalloc(sizeof(struct SAA));

    if (elem_len >= SAA_BLKLEN)
	s->blk_len = elem_len;
    else
	s->blk_len = SAA_BLKLEN - (SAA_BLKLEN % elem_len);

    s->elem_len = elem_len;
    s->length = s->blk_len;
    data = nasm_malloc(s->blk_len);
    s->nblkptrs = s->nblks = 1;
    s->blk_ptrs = nasm_malloc(sizeof(char *));
    s->blk_ptrs[0] = data;
    s->wblk = s->rblk = &s->blk_ptrs[0];

    return s;
}

void saa_free(struct SAA *s)
{
    char **p;
    size_t n;

    for (p = s->blk_ptrs, n = s->nblks; n; p++, n--)
	nasm_free(*p);

    nasm_free(s->blk_ptrs);
    nasm_free(s);
}

/* Add one allocation block to an SAA */
static void saa_extend(struct SAA *s)
{
    size_t blkn = s->nblks++;
    
    if (blkn >= s->nblkptrs) {
	size_t rindex = s->rblk - s->blk_ptrs;
	size_t windex = s->wblk - s->blk_ptrs;

	s->nblkptrs <<= 1;
	s->blk_ptrs = nasm_realloc(s->blk_ptrs, s->nblkptrs*sizeof(char *));

	s->rblk = s->blk_ptrs + rindex;
	s->wblk = s->blk_ptrs + windex;
    }

    s->blk_ptrs[blkn] = nasm_malloc(s->blk_len);
    s->length += s->blk_len;
}

void *saa_wstruct(struct SAA *s)
{
    void *p;

    if (s->wpos % s->elem_len)
	    nasm_malloc_error(ERR_PANIC|ERR_NOFILE,
			      "misaligned wpos in saa_wstruct");

    if (s->wpos + s->elem_len > s->blk_len) {
	if (s->wpos != s->blk_len)
	    nasm_malloc_error(ERR_PANIC|ERR_NOFILE,
			      "unfilled block in saa_wstruct");

	if (s->wptr + s->elem_len > s->length)
	    saa_extend(s);
	s->wblk++;
	s->wpos = 0;
    }

    p = *s->wblk + s->wpos;
    s->wpos += s->elem_len;
    s->wptr += s->elem_len;

    if (s->wptr > s->datalen)
	s->datalen = s->wptr;

    return p;
}

void saa_wbytes(struct SAA *s, const void *data, size_t len)
{
    const char *d = data;

    while (len) {
        size_t l = s->blk_len - s->wpos;
        if (l > len)
            l = len;
        if (l) {
            if (d) {
                memcpy(*s->wblk + s->wpos, d, l);
                d += l;
            } else
                memset(*s->wblk + s->wpos, 0, l);
            s->wpos += l;
	    s->wptr += l;
            len -= l;

	    if (s->datalen < s->wptr)
		s->datalen = s->wptr;
        }
        if (len) {
	    if (s->wptr >= s->length)
		saa_extend(s);
	    s->wblk++;
	    s->wpos = 0;
	}
    }
}

void saa_rewind(struct SAA *s)
{
    s->rblk = s->blk_ptrs;
    s->rpos = s->rptr = 0;
}

void *saa_rstruct(struct SAA *s)
{
    void *p;

    if (s->rptr + s->elem_len > s->datalen)
	return NULL;

    if (s->rpos % s->elem_len)
	    nasm_malloc_error(ERR_PANIC|ERR_NOFILE,
			      "misaligned rpos in saa_rstruct");

    if (s->rpos + s->elem_len > s->blk_len) {
	s->rblk++;
	s->rpos = 0;
    }

    p = *s->rblk + s->rpos;
    s->rpos += s->elem_len;
    s->rptr += s->elem_len;

    return p;
}

const void *saa_rbytes(struct SAA *s, size_t *lenp)
{
    const void *p;
    size_t len;

    if (s->rptr >= s->datalen) {
	*lenp = 0;
	return NULL;
    }

    if (s->rpos >= s->blk_len) {
	s->rblk++;
	s->rpos = 0;
    }

    len = *lenp;
    if (len > s->datalen - s->rptr)
	len = s->datalen - s->rptr;
    if (len > s->blk_len - s->rpos)
	len = s->blk_len - s->rpos;

    *lenp = len;
    p = *s->rblk + s->rpos;

    s->rpos += len;
    s->rptr += len;

    return p;
}

void saa_rnbytes(struct SAA *s, void *data, size_t len)
{
    char *d = data;

    if (s->rptr + len > s->datalen) {
	nasm_malloc_error(ERR_PANIC|ERR_NOFILE, "overrun in saa_rnbytes");
	return;
    }

    while (len) {
        size_t l;
	const void *p;

	l = len;
	p = saa_rbytes(s, &l);

	memcpy(d, p, l);
	d   += l;
	len -= l;
    }
}

/* Same as saa_rnbytes, except position the counter first */
void saa_fread(struct SAA *s, size_t posn, void *data, size_t len)
{
    size_t ix;
    
    if (posn+len > s->datalen) {
	nasm_malloc_error(ERR_PANIC|ERR_NOFILE, "overrun in saa_fread");
	return;
    }

    ix = posn / s->blk_len;
    s->rptr = posn;
    s->rpos = posn % s->blk_len;
    s->rblk = &s->blk_ptrs[ix];

    saa_rnbytes(s, data, len);
}

/* Same as saa_wbytes, except position the counter first */
void saa_fwrite(struct SAA *s, size_t posn, const void *data, size_t len)
{
    size_t ix;
    
    if (posn > s->datalen) {
	/* Seek beyond the end of the existing array not supported */
	nasm_malloc_error(ERR_PANIC|ERR_NOFILE, "overrun in saa_fwrite");
	return;
    }

    ix = posn / s->blk_len;
    s->wptr = posn;
    s->wpos = posn % s->blk_len;
    s->wblk = &s->blk_ptrs[ix];

    if (!s->wpos) {
	s->wpos = s->blk_len;
	s->wblk--;
    }

    saa_wbytes(s, data, len);
}

void saa_fpwrite(struct SAA *s, FILE * fp)
{
    const char *data;
    size_t len;

    saa_rewind(s);
    while (len = s->datalen, (data = saa_rbytes(s, &len)) != NULL)
        fwrite(data, 1, len, fp);
}

/*
 * Common list of prefix names
 */
static const char *prefix_names[] = {
    "a16", "a32", "lock", "o16", "o32", "rep", "repe", "repne",
    "repnz", "repz", "times"
};

const char *prefix_name(int token)
{
    unsigned int prefix = token-PREFIX_ENUM_START;
    if (prefix > sizeof prefix_names / sizeof(const char *))
	return NULL;

    return prefix_names[prefix];
}

/*
 * Binary search.
 */
int bsi(char *string, const char **array, int size)
{
    int i = -1, j = size;       /* always, i < index < j */
    while (j - i >= 2) {
        int k = (i + j) / 2;
        int l = strcmp(string, array[k]);
        if (l < 0)              /* it's in the first half */
            j = k;
        else if (l > 0)         /* it's in the second half */
            i = k;
        else                    /* we've got it :) */
            return k;
    }
    return -1;                  /* we haven't got it :( */
}

int bsii(char *string, const char **array, int size)
{
    int i = -1, j = size;       /* always, i < index < j */
    while (j - i >= 2) {
        int k = (i + j) / 2;
        int l = nasm_stricmp(string, array[k]);
        if (l < 0)              /* it's in the first half */
            j = k;
        else if (l > 0)         /* it's in the second half */
            i = k;
        else                    /* we've got it :) */
            return k;
    }
    return -1;                  /* we haven't got it :( */
}

static char *file_name = NULL;
static int32_t line_number = 0;

char *src_set_fname(char *newname)
{
    char *oldname = file_name;
    file_name = newname;
    return oldname;
}

int32_t src_set_linnum(int32_t newline)
{
    int32_t oldline = line_number;
    line_number = newline;
    return oldline;
}

int32_t src_get_linnum(void)
{
    return line_number;
}

int src_get(int32_t *xline, char **xname)
{
    if (!file_name || !*xname || strcmp(*xname, file_name)) {
        nasm_free(*xname);
        *xname = file_name ? nasm_strdup(file_name) : NULL;
        *xline = line_number;
        return -2;
    }
    if (*xline != line_number) {
        int32_t tmp = line_number - *xline;
        *xline = line_number;
        return tmp;
    }
    return 0;
}

void nasm_quote(char **str)
{
    int ln = strlen(*str);
    char q = (*str)[0];
    char *p;
    if (ln > 1 && (*str)[ln - 1] == q && (q == '"' || q == '\''))
        return;
    q = '"';
    if (strchr(*str, q))
        q = '\'';
    p = nasm_malloc(ln + 3);
    strcpy(p + 1, *str);
    nasm_free(*str);
    p[ln + 1] = p[0] = q;
    p[ln + 2] = 0;
    *str = p;
}

char *nasm_strcat(char *one, char *two)
{
    char *rslt;
    int l1 = strlen(one);
    rslt = nasm_malloc(l1 + strlen(two) + 1);
    strcpy(rslt, one);
    strcpy(rslt + l1, two);
    return rslt;
}

void null_debug_init(struct ofmt *of, void *id, FILE * fp, efunc error)
{
	(void)of;
	(void)id;
	(void)fp;
	(void)error;
}
void null_debug_linenum(const char *filename, int32_t linenumber, int32_t segto)
{
	(void)filename;
	(void)linenumber;
	(void)segto;	
}
void null_debug_deflabel(char *name, int32_t segment, int32_t offset,
                         int is_global, char *special)
{
	(void)name;
	(void)segment;
	(void)offset;
	(void)is_global;
	(void)special;
}
void null_debug_routine(const char *directive, const char *params)
{
	(void)directive;
	(void)params;
}
void null_debug_typevalue(int32_t type)
{
	(void)type;
}
void null_debug_output(int type, void *param)
{
	(void)type;
	(void)param;
}
void null_debug_cleanup(void)
{
}

struct dfmt null_debug_form = {
    "Null debug format",
    "null",
    null_debug_init,
    null_debug_linenum,
    null_debug_deflabel,
    null_debug_routine,
    null_debug_typevalue,
    null_debug_output,
    null_debug_cleanup
};

struct dfmt *null_debug_arr[2] = { &null_debug_form, NULL };