jsopcode.c

java script test programing source code

    if (nb > 0 && !SprintAlloc(sp, nb))
        return -1;

    /* Advance offset and copy s into sp's buffer. */
    offset = sp->offset;
    sp->offset += len;
    bp = sp->base + offset;
    memmove(bp, s, len);
    bp[len] = 0;
    return offset;
}

static ptrdiff_t
SprintCString(Sprinter *sp, const char *s)
{
    return SprintPut(sp, s, strlen(s));
}

static ptrdiff_t
Sprint(Sprinter *sp, const char *format, ...)
{
    va_list ap;
    char *bp;
    ptrdiff_t offset;

    va_start(ap, format);
    bp = JS_vsmprintf(format, ap);      /* XXX vsaprintf */
    va_end(ap);
    if (!bp) {
        JS_ReportOutOfMemory(sp->context);
        return -1;
    }
    offset = SprintCString(sp, bp);
    free(bp);
    return offset;
}

const jschar js_EscapeMap[] = {
    '\b', 'b',
    '\f', 'f',
    '\n', 'n',
    '\r', 'r',
    '\t', 't',
    '\v', 'v',
    '"',  '"',
    '\'', '\'',
    '\\', '\\',
    0
};

#define DONT_ESCAPE     0x10000

static char *
QuoteString(Sprinter *sp, JSString *str, uint32 quote)
{
    JSBool dontEscape, ok;
    jschar qc, c;
    ptrdiff_t off, len, nb;
    const jschar *s, *t, *u, *z;
    char *bp;

    /* Sample off first for later return value pointer computation. */
    dontEscape = (quote & DONT_ESCAPE) != 0;
    qc = (jschar) quote;
    off = sp->offset;
    if (qc && Sprint(sp, "%c", (char)qc) < 0)
        return NULL;

    /* Loop control variables: z points at end of string sentinel. */
    s = JSSTRING_CHARS(str);
    z = s + JSSTRING_LENGTH(str);
    for (t = s; t < z; s = ++t) {
        /* Move t forward from s past un-quote-worthy characters. */
        c = *t;
        while (JS_ISPRINT(c) && c != qc && c != '\\' && !(c >> 8)) {
            c = *++t;
            if (t == z)
                break;
        }
        len = PTRDIFF(t, s, jschar);

        /* Allocate space for s, including the '\0' at the end. */
        nb = (sp->offset + len + 1) - sp->size;
        if (nb > 0 && !SprintAlloc(sp, nb))
            return NULL;

        /* Advance sp->offset and copy s into sp's buffer. */
        bp = sp->base + sp->offset;
        sp->offset += len;
        while (--len >= 0)
            *bp++ = (char) *s++;
        *bp = '\0';

        if (t == z)
            break;

        /* Use js_EscapeMap, \u, or \x only if necessary. */
        if ((u = js_strchr(js_EscapeMap, c)) != NULL) {
            ok = dontEscape
                 ? Sprint(sp, "%c", (char)c) >= 0
                 : Sprint(sp, "\\%c", (char)u[1]) >= 0;
        } else {
#ifdef JS_C_STRINGS_ARE_UTF8
            /* If this is a surrogate pair, make sure to print the pair. */
            if (c >= 0xD800 && c <= 0xDBFF) {
                jschar buffer[3];
                buffer[0] = c;
                buffer[1] = *++t;
                buffer[2] = 0;
                if (t == z) {
                    char numbuf[10];
                    JS_snprintf(numbuf, sizeof numbuf, "0x%x", c);
                    JS_ReportErrorFlagsAndNumber(sp->context, JSREPORT_ERROR,
                                                 js_GetErrorMessage, NULL,
                                                 JSMSG_BAD_SURROGATE_CHAR,
                                                 numbuf);
                    ok = JS_FALSE;
                    break;
                }
                ok = Sprint(sp, "%hs", buffer) >= 0;
            } else {
                /* Print as UTF-8 string. */
                ok = Sprint(sp, "%hc", c) >= 0;
            }
#else
            /* Use \uXXXX or \xXX  if the string can't be displayed as UTF-8. */
            ok = Sprint(sp, (c >> 8) ? "\\u%04X" : "\\x%02X", c) >= 0;
#endif
        }
        if (!ok)
            return NULL;
    }

    /* Sprint the closing quote and return the quoted string. */
    if (qc && Sprint(sp, "%c", (char)qc) < 0)
        return NULL;

    /*
     * If we haven't Sprint'd anything yet, Sprint an empty string so that
     * the OFF2STR below gives a valid result.
     */
    if (off == sp->offset && Sprint(sp, "") < 0)
        return NULL;
    return OFF2STR(sp, off);
}

JSString *
js_QuoteString(JSContext *cx, JSString *str, jschar quote)
{
    void *mark;
    Sprinter sprinter;
    char *bytes;
    JSString *escstr;

    mark = JS_ARENA_MARK(&cx->tempPool);
    INIT_SPRINTER(cx, &sprinter, &cx->tempPool, 0);
    bytes = QuoteString(&sprinter, str, quote);
    escstr = bytes ? JS_NewStringCopyZ(cx, bytes) : NULL;
    JS_ARENA_RELEASE(&cx->tempPool, mark);
    return escstr;
}

/************************************************************************/

#if JS_HAS_BLOCK_SCOPE
typedef enum JSBraceState {
    ALWAYS_BRACE,
    MAYBE_BRACE,
    DONT_BRACE
} JSBraceState;
#endif

struct JSPrinter {
    Sprinter        sprinter;       /* base class state */
    JSArenaPool     pool;           /* string allocation pool */
    uintN           indent;         /* indentation in spaces */
    JSPackedBool    pretty;         /* pretty-print: indent, use newlines */
    JSPackedBool    grouped;        /* in parenthesized expression context */
    JSScript        *script;        /* script being printed */
    jsbytecode      *dvgfence;      /* js_DecompileValueGenerator fencepost */
    JSScope         *scope;         /* script function scope */
#if JS_HAS_BLOCK_SCOPE
    JSBraceState    braceState;     /* remove braces around let declaration */
    ptrdiff_t       spaceOffset;    /* -1 or offset of space before maybe-{ */
#endif
};

/*
 * Hack another flag, a la JS_DONT_PRETTY_PRINT, into uintN indent parameters
 * to functions such as js_DecompileFunction and js_NewPrinter.  This time, as
 * opposed to JS_DONT_PRETTY_PRINT back in the dark ages, we can assume that a
 * uintN is at least 32 bits.
 */
#define JS_IN_GROUP_CONTEXT 0x10000

JSPrinter *
js_NewPrinter(JSContext *cx, const char *name, uintN indent, JSBool pretty)
{
    JSPrinter *jp;

    jp = (JSPrinter *) JS_malloc(cx, sizeof(JSPrinter));
    if (!jp)
        return NULL;
    INIT_SPRINTER(cx, &jp->sprinter, &jp->pool, 0);
    JS_InitArenaPool(&jp->pool, name, 256, 1);
    jp->indent = indent & ~JS_IN_GROUP_CONTEXT;
    jp->pretty = pretty;
    jp->grouped = (indent & JS_IN_GROUP_CONTEXT) != 0;
    jp->script = NULL;
    jp->dvgfence = NULL;
    jp->scope = NULL;
#if JS_HAS_BLOCK_SCOPE
    jp->braceState = ALWAYS_BRACE;
    jp->spaceOffset = -1;
#endif
    return jp;
}

void
js_DestroyPrinter(JSPrinter *jp)
{
    JS_FinishArenaPool(&jp->pool);
    JS_free(jp->sprinter.context, jp);
}

JSString *
js_GetPrinterOutput(JSPrinter *jp)
{
    JSContext *cx;
    JSString *str;

    cx = jp->sprinter.context;
    if (!jp->sprinter.base)
        return cx->runtime->emptyString;
    str = JS_NewStringCopyZ(cx, jp->sprinter.base);
    if (!str)
        return NULL;
    JS_FreeArenaPool(&jp->pool);
    INIT_SPRINTER(cx, &jp->sprinter, &jp->pool, 0);
    return str;
}

#if !JS_HAS_BLOCK_SCOPE
# define SET_MAYBE_BRACE(jp)    jp
# define CLEAR_MAYBE_BRACE(jp)  jp
#else
# define SET_MAYBE_BRACE(jp)    ((jp)->braceState = MAYBE_BRACE, (jp))
# define CLEAR_MAYBE_BRACE(jp)  ((jp)->braceState = ALWAYS_BRACE, (jp))

static void
SetDontBrace(JSPrinter *jp)
{
    ptrdiff_t offset;
    const char *bp;

    /* When not pretty-printing, newline after brace is chopped. */
    JS_ASSERT(jp->spaceOffset < 0);
    offset = jp->sprinter.offset - (jp->pretty ? 3 : 2);

    /* The shortest case is "if (x) {". */
    JS_ASSERT(offset >= 6);
    bp = jp->sprinter.base;
    if (bp[offset+0] == ' ' && bp[offset+1] == '{') {
        JS_ASSERT(!jp->pretty || bp[offset+2] == '\n');
        jp->spaceOffset = offset;
        jp->braceState = DONT_BRACE;
    }
}
#endif

int
js_printf(JSPrinter *jp, const char *format, ...)
{
    va_list ap;
    char *bp, *fp;
    int cc;

    if (*format == '\0')
        return 0;

    va_start(ap, format);

    /* If pretty-printing, expand magic tab into a run of jp->indent spaces. */
    if (*format == '\t') {
        format++;

#if JS_HAS_BLOCK_SCOPE
        if (*format == '}' && jp->braceState != ALWAYS_BRACE) {
            JSBraceState braceState;

            braceState = jp->braceState;
            jp->braceState = ALWAYS_BRACE;
            if (braceState == DONT_BRACE) {
                ptrdiff_t offset, delta, from;

                JS_ASSERT(format[1] == '\n' || format[1] == ' ');
                offset = jp->spaceOffset;
                JS_ASSERT(offset >= 6);

                /* Replace " {\n" at the end of jp->sprinter with "\n". */
                bp = jp->sprinter.base;
                if (bp[offset+0] == ' ' && bp[offset+1] == '{') {
                    delta = 2;
                    if (jp->pretty) {
                        /* If pretty, we don't have to worry about 'else'. */
                        JS_ASSERT(bp[offset+2] == '\n');
                    } else if (bp[offset-1] != ')') {
                        /* Must keep ' ' to avoid 'dolet' or 'elselet'. */
                        ++offset;
                        delta = 1;
                    }

                    from = offset + delta;
                    memmove(bp + offset, bp + from, jp->sprinter.offset - from);
                    jp->sprinter.offset -= delta;
                    jp->spaceOffset = -1;

                    format += 2;
                    if (*format == '\0')
                        return 0;
                }
            }
        }
#endif

        if (jp->pretty && Sprint(&jp->sprinter, "%*s", jp->indent, "") < 0)
            return -1;
    }

    /* Suppress newlines (must be once per format, at the end) if not pretty. */
    fp = NULL;
    if (!jp->pretty && format[cc = strlen(format) - 1] == '\n') {
        fp = JS_strdup(jp->sprinter.context, format);
        if (!fp)
            return -1;
        fp[cc] = '\0';
        format = fp;
    }

    /* Allocate temp space, convert format, and put. */
    bp = JS_vsmprintf(format, ap);      /* XXX vsaprintf */
    if (fp) {
        JS_free(jp->sprinter.context, fp);
        format = NULL;
    }
    if (!bp) {
        JS_ReportOutOfMemory(jp->sprinter.context);
        return -1;
    }

    cc = strlen(bp);
    if (SprintPut(&jp->sprinter, bp, (size_t)cc) < 0)
        cc = -1;
    free(bp);

    va_end(ap);
    return cc;
}

JSBool
js_puts(JSPrinter *jp, const char *s)
{
    return SprintCString(&jp->sprinter, s) >= 0;
}

/************************************************************************/

typedef struct SprintStack {
    Sprinter    sprinter;       /* sprinter for postfix to infix buffering */
    ptrdiff_t   *offsets;       /* stack of postfix string offsets */
    jsbytecode  *opcodes;       /* parallel stack of JS opcodes */
    uintN       top;            /* top of stack index */
    uintN       inArrayInit;    /* array initialiser/comprehension level */
    JSPrinter   *printer;       /* permanent output goes here */
} SprintStack;

/*
 * Get a stacked offset from ss->sprinter.base, or if the stacked value |off|
 * is negative, lazily fetch the generating pc at |spindex = 1 + off| and try
 * to decompile the code that generated the missing value.  This is used when
 * reporting errors, where the model stack will lack |pcdepth| non-negative
 * offsets (see js_DecompileValueGenerator and js_DecompileCode).
 *
 * If the stacked offset is -1, return 0 to index the NUL padding at the start
 * of ss->sprinter.base.  If this happens, it means there is a decompiler bug
 * to fix, but it won't violate memory safety.
 */
static ptrdiff_t
GetOff(SprintStack *ss, uintN i)
{
    ptrdiff_t off;
    JSString *str;

    off = ss->offsets[i];
    if (off < 0) {
#if defined DEBUG_brendan || defined DEBUG_mrbkap || defined DEBUG_crowder
        JS_ASSERT(off < -1);
#endif
        if (++off == 0) {
            if (!ss->sprinter.base && SprintPut(&ss->sprinter, "", 0) >= 0)
                memset(ss->sprinter.base, 0, ss->sprinter.offset);
            return 0;