NAME

src/packfile/pf_items.c - Fetch/store packfile data

DESCRIPTION

Low level packfile functions to fetch and store Parrot data, i.e. INTVAL, FLOATVAL, STRING ...

PF_fetch_<item>() functions retrieve the datatype item from the opcode stream and convert byteordering or binary format on the fly, depending on the packfile header.

PF_store_<item>() functions write the datatype item to the stream as is. These functions don't check the available size.

PF_size_<item>() functions return the store size of item in opcode_t units.

Functions

*/

#include "parrot/parrot.h" #include <assert.h>

/* HEADER: include/parrot/packfile.h */

#define TRACE_PACKFILE 0 #define TRACE_PACKFILE_PMC 0

/* * round val up to whole size, return result in bytes */ #define ROUND_UP_B(val,size) ((((val) + (size - 1))/(size)) * (size))

/* * round val up to whole opcode_t, return result in opcodes */ #define ROUND_UP(val,size) (((val) + ((size) - 1))/(size))

/* * low level FLOATVAL fetch and convert functions * * * convert i386 LE 12 byte long double to IEEE 754 8 byte double */ static void cvt_num12_num8(unsigned char *dest, const unsigned char *src) { int expo, i, s; #ifdef __LCC__ int expo2; #endif

    memset (dest, 0, 8);
    /* exponents 15 -> 11 bits */
    s = src[9] & 0x80; /* sign */
    expo = ((src[9] & 0x7f)<< 8 | src[8]);
    if (expo == 0) {
nul:
        if (s)
            dest[7] |= 0x80;
        return;
    }
#ifdef __LCC__
    /* Yet again, LCC blows up mysteriously until a temporary variable is
     * added. */
    expo2 = expo - 16383;
    expo  = expo2;
#else
    expo -= 16383;       /* - bias */
#endif
    expo += 1023;       /* + bias 8byte */
    if (expo <= 0)       /* underflow */
        goto nul;
    if (expo > 0x7ff) {  /* inf/nan */
        dest[7] = 0x7f;
        dest[6] = src[7] == 0xc0 ? 0xf8 : 0xf0 ;
        goto nul;
    }
    expo <<= 4;
    dest[6] = (expo & 0xff);
    dest[7] = (expo & 0x7f00) >> 8;
    if (s)
        dest[7] |= 0x80;
    /* long double frac 63 bits => 52 bits
       src[7] &= 0x7f; reset integer bit */
    for (i = 0; i < 6; i++) {
        dest[i+1] |= (i==5 ? src[7]&0x7f : src[i+2]) >> 3;
        dest[i] |= (src[i+2] & 0x1f) << 5;
    }
    dest[0] |= src[1] >> 3;
}

static void cvt_num12_num8_be(unsigned char *dest, const unsigned char *src) { cvt_num12_num8(dest, src); /* TODO endianize */ internal_exception(1, "TODO cvt_num12_num8_be\n"); }

static void cvt_num12_num8_le(unsigned char *dest, unsigned char *src) { unsigned char b[8]; cvt_num12_num8(b, src); fetch_buf_le_8(dest, b); } static opcode_t fetch_op_test(unsigned char *b) { union { unsigned char buf[4]; opcode_t o; } u; fetch_buf_le_4(u.buf, b); return u.o; }

/* * opcode fetch helper function * * This is mostly wrong or at least untested * * Fetch an opcode and convert to LE */ static opcode_t fetch_op_mixed_le(unsigned char *b) { #if OPCODE_T_SIZE == 4 union { unsigned char buf[8]; opcode_t o[2]; } u; /* wordsize = 8 then */ fetch_buf_le_8(u.buf, (unsigned char *) b); return u.o[0]; /* or u.o[1] */ #else union { unsigned char buf[4]; opcode_t o; } u;

    /* wordsize = 4 */
    u.o = 0;
    fetch_buf_le_4(u.buf, b);
    return u.o;
#endif
}

/* * Fetch an opcode and convert to BE */ static opcode_t fetch_op_mixed_be(unsigned char *b) { #if OPCODE_T_SIZE == 4 union { unsigned char buf[8]; opcode_t o[2]; } u; /* wordsize = 8 then */ fetch_buf_be_8(u.buf, (unsigned char *) b); return u.o[1]; /* or u.o[0] */ #else union { unsigned char buf[4]; opcode_t o; } u; /* wordsize = 4 */ u.o = 0; fetch_buf_be_4(u.buf, b); return u.o; #endif }

static opcode_t fetch_op_be_4(unsigned char *b) { union { unsigned char buf[4]; opcode_t o; } u; fetch_buf_be_4(u.buf, b); #if PARROT_BIGENDIAN # if OPCODE_T_SIZE == 8 return u.o >> 32; # else return u.o; # endif #else # if OPCODE_T_SIZE == 8 return (opcode_t)(fetch_iv_le((INTVAL)u.o) & 0xffffffff); # else return (opcode_t) fetch_iv_le((INTVAL)u.o); # endif #endif }

static opcode_t fetch_op_be_8(unsigned char *b) { union { unsigned char buf[8]; opcode_t o[2]; } u; fetch_buf_be_8(u.buf, b); #if PARROT_BIGENDIAN # if OPCODE_T_SIZE == 8 return u.o[0]; # else return u.o[1]; # endif #else return (opcode_t)fetch_iv_le((INTVAL)u.o[0]); #endif }

static opcode_t fetch_op_le_4(unsigned char *b) { union { unsigned char buf[4]; opcode_t o; } u; fetch_buf_le_4(u.buf, b); #if PARROT_BIGENDIAN # if OPCODE_T_SIZE == 8 return u.o >> 32; # else return (opcode_t) fetch_iv_be((INTVAL)u.o); # endif #else # if OPCODE_T_SIZE == 8 return u.o & 0xffffffff; # else return u.o; # endif #endif }

static opcode_t fetch_op_le_8(unsigned char *b) { union { unsigned char buf[8]; opcode_t o[2]; } u; fetch_buf_le_8(u.buf, b); #if PARROT_BIGENDIAN # if OPCODE_T_SIZE == 8 return u.o[0]; # else return (opcode_t)fetch_op_be((INTVAL)u.o[1]); # endif #else return u.o[0]; #endif }

/*

FUNCDOC: PF_fetch_opcode

Fetch an opcode_t from the stream, converting byteorder if needed.

*/

opcode_t PF_fetch_opcode(PackFile *pf /*NULLOK*/, opcode_t **stream /*NN*/) /* WARN_UNUSED */ { opcode_t o; if (!pf || !pf->fetch_op) return *(*stream)++; #if TRACE_PACKFILE == 2 PIO_eprintf(NULL, "PF_fetch_opcode: Reordering.\n"); #endif o = (pf->fetch_op)(*((unsigned char **)stream)); *((unsigned char **) (stream)) += pf->header->wordsize; return o; }

/*

FUNCDOC: PF_store_opcode

Store an opcode_t to stream as is.

*/

opcode_t* PF_store_opcode(opcode_t *cursor /*NN*/, opcode_t val) /* WARN_UNUSED */ { *cursor++ = val; return cursor; }

/*

FUNCDOC: PF_size_opcode

Return size of an item in opcode_t units, which is 1 per definitionem.

*/

size_t PF_size_opcode(void) /* CONST, WARN_UNUSED */ { return 1; }

/*

FUNCDOC: PF_fetch_integer

Fetch an INTVAL from the stream, converting byteorder if needed.

XXX assumes sizeof (INTVAL) == sizeof (opcode_t) - we don't have INTVAL size in the PackFile header.

*/

INTVAL PF_fetch_integer(PackFile *pf /*NULLOK*/, opcode_t **stream /*NN*/) /* WARN_UNUSED */ { INTVAL i; if (!pf || pf->fetch_iv == NULL) return *(*stream)++; i = (pf->fetch_iv)(*((unsigned char **)stream)); /* XXX assume sizeof (opcode_t) == sizeof (INTVAL) on the * machine producing this PBC */ *((unsigned char **) (stream)) += pf->header->wordsize; return i; }

/*

FUNCDOC: PF_store_integer

Store an INTVAL to stream as is.

*/

opcode_t* PF_store_integer(opcode_t *cursor, INTVAL val) { *cursor++ = (opcode_t)val; /* XXX */ return cursor; }

/*

FUNCDOC: PF_size_integer

Return store size of INTVAL in opcode_t units.

*/

size_t PF_size_integer(void) /* CONST, WARN_UNUSED */ { const size_t s = sizeof (INTVAL) / sizeof (opcode_t); return s ? s : 1; }

/*

FUNCDOC: PF_fetch_number

Fetch a FLOATVAL from the stream, converting byteorder if needed. Then advance stream pointer by amount of packfile float size.

*/

FLOATVAL PF_fetch_number(PackFile *pf /*NULLOK*/, opcode_t **stream /*NN*/) /* WARN_UNUSED */ { /* When we have alignment all squared away we don't need * to use memcpy() for native byteorder. */ FLOATVAL f; double d; if (!pf || !pf->fetch_nv) { #if TRACE_PACKFILE PIO_eprintf(NULL, "PF_fetch_number: Native [%d bytes]\n", sizeof (FLOATVAL)); #endif memcpy(&f, (char*)*stream, sizeof (FLOATVAL)); (*stream) += (sizeof (FLOATVAL) + sizeof (opcode_t) - 1)/ sizeof (opcode_t); return f; } f = (FLOATVAL) 0; #if TRACE_PACKFILE PIO_eprintf(NULL, "PF_fetch_number: Byteordering..\n"); #endif /* Here is where the size transforms get messy */ if (NUMVAL_SIZE == 8 && pf->header->floattype == 1) { (pf->fetch_nv)((unsigned char *)&f, (unsigned char *) *stream); *((unsigned char **) (stream)) += 12; } else { (pf->fetch_nv)((unsigned char *)&d, (unsigned char *) *stream); *((unsigned char **) (stream)) += 8; f = d; } return f; }

/*

FUNCDOC: PF_store_number

Write a FLOATVAL to the opcode stream as is.

*/

opcode_t* PF_store_number(opcode_t *cursor /*NN*/, const FLOATVAL *val /*NN*/) { opcode_t padded_size = (sizeof (FLOATVAL) + sizeof (opcode_t) - 1) / sizeof (opcode_t); mem_sys_memcopy(cursor, val, sizeof (FLOATVAL)); cursor += padded_size; return cursor; }

/*

FUNCDOC: PF_size_number

Return store size of FLOATVAL in opcode_t units.

*/

size_t PF_size_number(void) /* CONST, WARN_UNUSED */ { return ROUND_UP(sizeof (FLOATVAL), sizeof (opcode_t)); }

/*

FUNCDOC: PF_fetch_string

Fetch a STRING from bytecode and return a new STRING.

Opcode format is:

    opcode_t flags
    opcode_t encoding
    opcode_t type
    opcode_t size
    * data

*/

STRING * PF_fetch_string(Interp *interp /*NN*/, PackFile *pf /*NN*/, opcode_t **cursor /*NN*/) /* WARN_UNUSED */ { UINTVAL flags; opcode_t charset_nr; size_t size; STRING *s; const int wordsize = pf ? pf->header->wordsize : sizeof (opcode_t); const char *charset_name;

    flags = PF_fetch_opcode(pf, cursor);
    /* don't let PBC mess our internals - only constant or not */
    flags &= (PObj_constant_FLAG | PObj_private7_FLAG);
    charset_nr = PF_fetch_opcode(pf, cursor);

    /* These may need to be separate */
    size = (size_t)PF_fetch_opcode(pf, cursor);

/* #define TRACE_PACKFILE 1 */ #if TRACE_PACKFILE PIO_eprintf(NULL, "PF_fetch_string(): flags are 0x%04x...\n", flags); PIO_eprintf(NULL, "PF_fetch_string(): charset_nr is %ld...\n", charset_nr); PIO_eprintf(NULL, "PF_fetch_string(): size is %ld...\n", size); #endif

    charset_name = Parrot_charset_c_name(interp, charset_nr);
    s = string_make(interp, (char *)*cursor, size, charset_name, flags);

#if TRACE_PACKFILE PIO_eprintf(NULL, "PF_fetch_string(): string is: "); PIO_putps(interp, PIO_STDERR(interp), s); PIO_eprintf(NULL, "\n"); #endif

/* s = string_make(interp, *cursor, size, encoding_lookup_index(encoding), flags); */

    size = ROUND_UP_B(size, wordsize);
    *((unsigned char **) (cursor)) += size;
    return s;
}

/*

FUNCDOC: PF_store_string

Write a STRING to the opcode stream.

*/

opcode_t* PF_store_string(opcode_t *cursor /*NN*/, STRING *s /*NN*/) { opcode_t padded_size = s->bufused; char *charcursor; size_t i;

/* PIO_eprintf(NULL, "PF_store_string(): size is %ld...\n", s->bufused); */

    if (padded_size % sizeof (opcode_t)) {
        padded_size += sizeof (opcode_t) - (padded_size % sizeof (opcode_t));
    }

    *cursor++ = PObj_get_FLAGS(s); /* only constant_FLAG and private7 */
    /*
     * TODO as soon as we have dynamically loadable charsets
     *      we have to store the charset name, not the number
     *
     * TODO encoding
     *
     * see also PF_fetch_string
     */
    *cursor++ = Parrot_charset_number_of_str(NULL, s);
    *cursor++ = s->bufused;

    /* Switch to char * since rest of string is addressed by
     * characters to ensure padding.  */
    charcursor = (char *)cursor;

    if (s->strstart) {
        mem_sys_memcopy(charcursor, s->strstart, s->bufused);
        charcursor += s->bufused;

        if (s->bufused % sizeof (opcode_t)) {
            for (i = 0; i < (sizeof (opcode_t) -
                        (s->bufused % sizeof (opcode_t))); i++) {
                *charcursor++ = 0;
            }
        }
    }
    assert(((long)charcursor & 3) == 0);
    cursor = (opcode_t *)charcursor;

    return cursor;
}

/*

FUNCDOC: PF_size_string

Report store size of STRING in opcode_t units.

*/

size_t PF_size_string(const STRING *s /*NN*/) /* PURE, WARN_UNUSED */ { opcode_t padded_size = s->bufused;

    if (padded_size % sizeof (opcode_t)) {
        padded_size += sizeof (opcode_t) - (padded_size % sizeof (opcode_t));
    }

    /* Include space for flags, representation, and size fields.  */
    return 3 + (size_t)padded_size / sizeof (opcode_t);
}

/*

FUNCDOC: PF_fetch_cstring

Fetch a cstring from bytecode and return an allocated copy

*/

char * PF_fetch_cstring(PackFile *pf /*NN*/, opcode_t **cursor /*NN*/) /* WARN_UNUSED, MALLOC */ { const size_t str_len = strlen ((char *)(*cursor)) + 1; char * const p = (char *)mem_sys_allocate(str_len);

    if (p) {
        const int wordsize = pf->header->wordsize;

        strcpy(p, (char*) (*cursor));
        *((unsigned char **) (cursor)) += ROUND_UP_B(str_len, wordsize);
    }

    return p;
}

/*

FUNCDOC: PF_store_cstring

Write a 0-terminated string to the stream.

*/

opcode_t* PF_store_cstring(opcode_t *cursor /*NN*/, const char *s /*NN*/) /* WARN_UNUSED */ { strcpy((char *) cursor, s); return cursor + PF_size_cstring(s); }

/*

FUNCDOC: PF_size_cstring

Return store size of a C-string in opcode_t units.

*/

size_t PF_size_cstring(const char *s /*NN*/) /* PURE, WARN_UNUSED */ { size_t str_len;

    assert(s);
    str_len = strlen(s);
    return ROUND_UP(str_len + 1, sizeof (opcode_t));
}

/*

FUNCDOC: PackFile_assign_transforms

Assign transform functions to vtable.

*/

void PackFile_assign_transforms(PackFile *pf /*NN*/) { const int need_endianize = pf->header->byteorder != PARROT_BIGENDIAN; const int need_wordsize = pf->header->wordsize != sizeof (opcode_t);

    pf->need_endianize = need_endianize;
    pf->need_wordsize  = need_wordsize;
#if PARROT_BIGENDIAN
    /*
     * this Parrot is on a BIG ENDIAN machine
     */
    if (need_endianize) {
        if (pf->header->wordsize == 4)
            pf->fetch_op = fetch_op_le_4;
        else
            pf->fetch_op = fetch_op_le_8;
        if (pf->header->floattype == 0)
            pf->fetch_nv = fetch_buf_le_8;
        else if (pf->header->floattype == 1)
            pf->fetch_nv = cvt_num12_num8_le;
    }
    else {
        if (pf->header->wordsize == 4)
            pf->fetch_op = fetch_op_be_4;
        else
            pf->fetch_op = fetch_op_be_8;
    }
#else
    /*
     * this Parrot is on a LITTLE ENDIAN machine
     */
    if (need_endianize) {
        if (pf->header->wordsize == 4)
            pf->fetch_op = fetch_op_be_4;
        else
            pf->fetch_op = fetch_op_be_8;
        if (pf->header->floattype == 0)
            pf->fetch_nv = fetch_buf_be_8;
        else if (pf->header->floattype == 1)
            pf->fetch_nv = cvt_num12_num8_be;
    }
    else {
        if (pf->header->wordsize == 4)
            pf->fetch_op = fetch_op_le_4;
        else
            pf->fetch_op = fetch_op_le_8;
        if (NUMVAL_SIZE == 8 && pf->header->floattype == 1)
            pf->fetch_nv = cvt_num12_num8;
        else if (NUMVAL_SIZE != 8 && pf->header->floattype == 0)
            pf->fetch_nv = fetch_buf_le_8;
    }
#endif
    pf->fetch_iv = pf->fetch_op;
}

/*

HISTORY

Initial review by leo 2003.11.21

Most routines moved from src/packfile.c.

Renamed PackFile_* to PF_*

TODO

<PF_store_<type()>> - write an opcode_t stream to cursor in natural byte-ordering.

<PF_fetch_<type()>> - read items and possibly convert the foreign format.

<PF_size_<type()>> - return the needed size in opcode_t units.

*/

/* * Local variables: * c-file-style: "parrot" * End: * vim: expandtab shiftwidth=4: */