xref: /openbmc/qemu/scripts/decodetree.py (revision 3fdbf5d6794db253b0a5173204bbbcc8a17bc9d1)
1#!/usr/bin/env python
2# Copyright (c) 2018 Linaro Limited
3#
4# This library is free software; you can redistribute it and/or
5# modify it under the terms of the GNU Lesser General Public
6# License as published by the Free Software Foundation; either
7# version 2 of the License, or (at your option) any later version.
8#
9# This library is distributed in the hope that it will be useful,
10# but WITHOUT ANY WARRANTY; without even the implied warranty of
11# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12# Lesser General Public License for more details.
13#
14# You should have received a copy of the GNU Lesser General Public
15# License along with this library; if not, see <http://www.gnu.org/licenses/>.
16#
17
18#
19# Generate a decoding tree from a specification file.
20# See the syntax and semantics in docs/devel/decodetree.rst.
21#
22
23import os
24import re
25import sys
26import getopt
27
28insnwidth = 32
29insnmask = 0xffffffff
30fields = {}
31arguments = {}
32formats = {}
33patterns = []
34
35translate_prefix = 'trans'
36translate_scope = 'static '
37input_file = ''
38output_file = None
39output_fd = None
40insntype = 'uint32_t'
41decode_function = 'decode'
42
43re_ident = '[a-zA-Z][a-zA-Z0-9_]*'
44
45
46def error_with_file(file, lineno, *args):
47    """Print an error message from file:line and args and exit."""
48    global output_file
49    global output_fd
50
51    if lineno:
52        r = '{0}:{1}: error:'.format(file, lineno)
53    elif input_file:
54        r = '{0}: error:'.format(file)
55    else:
56        r = 'error:'
57    for a in args:
58        r += ' ' + str(a)
59    r += '\n'
60    sys.stderr.write(r)
61    if output_file and output_fd:
62        output_fd.close()
63        os.remove(output_file)
64    exit(1)
65
66def error(lineno, *args):
67    error_with_file(input_file, lineno, args)
68
69def output(*args):
70    global output_fd
71    for a in args:
72        output_fd.write(a)
73
74
75if sys.version_info >= (3, 4):
76    re_fullmatch = re.fullmatch
77else:
78    def re_fullmatch(pat, str):
79        return re.match('^' + pat + '$', str)
80
81
82def output_autogen():
83    output('/* This file is autogenerated by scripts/decodetree.py.  */\n\n')
84
85
86def str_indent(c):
87    """Return a string with C spaces"""
88    return ' ' * c
89
90
91def str_fields(fields):
92    """Return a string uniquely identifing FIELDS"""
93    r = ''
94    for n in sorted(fields.keys()):
95        r += '_' + n
96    return r[1:]
97
98
99def str_match_bits(bits, mask):
100    """Return a string pretty-printing BITS/MASK"""
101    global insnwidth
102
103    i = 1 << (insnwidth - 1)
104    space = 0x01010100
105    r = ''
106    while i != 0:
107        if i & mask:
108            if i & bits:
109                r += '1'
110            else:
111                r += '0'
112        else:
113            r += '.'
114        if i & space:
115            r += ' '
116        i >>= 1
117    return r
118
119
120def is_pow2(x):
121    """Return true iff X is equal to a power of 2."""
122    return (x & (x - 1)) == 0
123
124
125def ctz(x):
126    """Return the number of times 2 factors into X."""
127    r = 0
128    while ((x >> r) & 1) == 0:
129        r += 1
130    return r
131
132
133def is_contiguous(bits):
134    shift = ctz(bits)
135    if is_pow2((bits >> shift) + 1):
136        return shift
137    else:
138        return -1
139
140
141def eq_fields_for_args(flds_a, flds_b):
142    if len(flds_a) != len(flds_b):
143        return False
144    for k, a in flds_a.items():
145        if k not in flds_b:
146            return False
147    return True
148
149
150def eq_fields_for_fmts(flds_a, flds_b):
151    if len(flds_a) != len(flds_b):
152        return False
153    for k, a in flds_a.items():
154        if k not in flds_b:
155            return False
156        b = flds_b[k]
157        if a.__class__ != b.__class__ or a != b:
158            return False
159    return True
160
161
162class Field:
163    """Class representing a simple instruction field"""
164    def __init__(self, sign, pos, len):
165        self.sign = sign
166        self.pos = pos
167        self.len = len
168        self.mask = ((1 << len) - 1) << pos
169
170    def __str__(self):
171        if self.sign:
172            s = 's'
173        else:
174            s = ''
175        return str(self.pos) + ':' + s + str(self.len)
176
177    def str_extract(self):
178        if self.sign:
179            extr = 'sextract32'
180        else:
181            extr = 'extract32'
182        return '{0}(insn, {1}, {2})'.format(extr, self.pos, self.len)
183
184    def __eq__(self, other):
185        return self.sign == other.sign and self.sign == other.sign
186
187    def __ne__(self, other):
188        return not self.__eq__(other)
189# end Field
190
191
192class MultiField:
193    """Class representing a compound instruction field"""
194    def __init__(self, subs, mask):
195        self.subs = subs
196        self.sign = subs[0].sign
197        self.mask = mask
198
199    def __str__(self):
200        return str(self.subs)
201
202    def str_extract(self):
203        ret = '0'
204        pos = 0
205        for f in reversed(self.subs):
206            if pos == 0:
207                ret = f.str_extract()
208            else:
209                ret = 'deposit32({0}, {1}, {2}, {3})' \
210                      .format(ret, pos, 32 - pos, f.str_extract())
211            pos += f.len
212        return ret
213
214    def __ne__(self, other):
215        if len(self.subs) != len(other.subs):
216            return True
217        for a, b in zip(self.subs, other.subs):
218            if a.__class__ != b.__class__ or a != b:
219                return True
220        return False
221
222    def __eq__(self, other):
223        return not self.__ne__(other)
224# end MultiField
225
226
227class ConstField:
228    """Class representing an argument field with constant value"""
229    def __init__(self, value):
230        self.value = value
231        self.mask = 0
232        self.sign = value < 0
233
234    def __str__(self):
235        return str(self.value)
236
237    def str_extract(self):
238        return str(self.value)
239
240    def __cmp__(self, other):
241        return self.value - other.value
242# end ConstField
243
244
245class FunctionField:
246    """Class representing a field passed through an expander"""
247    def __init__(self, func, base):
248        self.mask = base.mask
249        self.sign = base.sign
250        self.base = base
251        self.func = func
252
253    def __str__(self):
254        return self.func + '(' + str(self.base) + ')'
255
256    def str_extract(self):
257        return self.func + '(' + self.base.str_extract() + ')'
258
259    def __eq__(self, other):
260        return self.func == other.func and self.base == other.base
261
262    def __ne__(self, other):
263        return not self.__eq__(other)
264# end FunctionField
265
266
267class Arguments:
268    """Class representing the extracted fields of a format"""
269    def __init__(self, nm, flds, extern):
270        self.name = nm
271        self.extern = extern
272        self.fields = sorted(flds)
273
274    def __str__(self):
275        return self.name + ' ' + str(self.fields)
276
277    def struct_name(self):
278        return 'arg_' + self.name
279
280    def output_def(self):
281        if not self.extern:
282            output('typedef struct {\n')
283            for n in self.fields:
284                output('    int ', n, ';\n')
285            output('} ', self.struct_name(), ';\n\n')
286# end Arguments
287
288
289class General:
290    """Common code between instruction formats and instruction patterns"""
291    def __init__(self, name, lineno, base, fixb, fixm, udfm, fldm, flds):
292        self.name = name
293        self.file = input_file
294        self.lineno = lineno
295        self.base = base
296        self.fixedbits = fixb
297        self.fixedmask = fixm
298        self.undefmask = udfm
299        self.fieldmask = fldm
300        self.fields = flds
301
302    def __str__(self):
303        r = self.name
304        if self.base:
305            r = r + ' ' + self.base.name
306        else:
307            r = r + ' ' + str(self.fields)
308        r = r + ' ' + str_match_bits(self.fixedbits, self.fixedmask)
309        return r
310
311    def str1(self, i):
312        return str_indent(i) + self.__str__()
313# end General
314
315
316class Format(General):
317    """Class representing an instruction format"""
318
319    def extract_name(self):
320        return 'extract_' + self.name
321
322    def output_extract(self):
323        output('static void ', self.extract_name(), '(',
324               self.base.struct_name(), ' *a, ', insntype, ' insn)\n{\n')
325        for n, f in self.fields.items():
326            output('    a->', n, ' = ', f.str_extract(), ';\n')
327        output('}\n\n')
328# end Format
329
330
331class Pattern(General):
332    """Class representing an instruction pattern"""
333
334    def output_decl(self):
335        global translate_scope
336        global translate_prefix
337        output('typedef ', self.base.base.struct_name(),
338               ' arg_', self.name, ';\n')
339        output(translate_scope, 'bool ', translate_prefix, '_', self.name,
340               '(DisasContext *ctx, arg_', self.name, ' *a);\n')
341
342    def output_code(self, i, extracted, outerbits, outermask):
343        global translate_prefix
344        ind = str_indent(i)
345        arg = self.base.base.name
346        output(ind, '/* ', self.file, ':', str(self.lineno), ' */\n')
347        if not extracted:
348            output(ind, self.base.extract_name(), '(&u.f_', arg, ', insn);\n')
349        for n, f in self.fields.items():
350            output(ind, 'u.f_', arg, '.', n, ' = ', f.str_extract(), ';\n')
351        output(ind, 'return ', translate_prefix, '_', self.name,
352               '(ctx, &u.f_', arg, ');\n')
353# end Pattern
354
355
356def parse_field(lineno, name, toks):
357    """Parse one instruction field from TOKS at LINENO"""
358    global fields
359    global re_ident
360    global insnwidth
361
362    # A "simple" field will have only one entry;
363    # a "multifield" will have several.
364    subs = []
365    width = 0
366    func = None
367    for t in toks:
368        if re_fullmatch('!function=' + re_ident, t):
369            if func:
370                error(lineno, 'duplicate function')
371            func = t.split('=')
372            func = func[1]
373            continue
374
375        if re_fullmatch('[0-9]+:s[0-9]+', t):
376            # Signed field extract
377            subtoks = t.split(':s')
378            sign = True
379        elif re_fullmatch('[0-9]+:[0-9]+', t):
380            # Unsigned field extract
381            subtoks = t.split(':')
382            sign = False
383        else:
384            error(lineno, 'invalid field token "{0}"'.format(t))
385        po = int(subtoks[0])
386        le = int(subtoks[1])
387        if po + le > insnwidth:
388            error(lineno, 'field {0} too large'.format(t))
389        f = Field(sign, po, le)
390        subs.append(f)
391        width += le
392
393    if width > insnwidth:
394        error(lineno, 'field too large')
395    if len(subs) == 1:
396        f = subs[0]
397    else:
398        mask = 0
399        for s in subs:
400            if mask & s.mask:
401                error(lineno, 'field components overlap')
402            mask |= s.mask
403        f = MultiField(subs, mask)
404    if func:
405        f = FunctionField(func, f)
406
407    if name in fields:
408        error(lineno, 'duplicate field', name)
409    fields[name] = f
410# end parse_field
411
412
413def parse_arguments(lineno, name, toks):
414    """Parse one argument set from TOKS at LINENO"""
415    global arguments
416    global re_ident
417
418    flds = []
419    extern = False
420    for t in toks:
421        if re_fullmatch('!extern', t):
422            extern = True
423            continue
424        if not re_fullmatch(re_ident, t):
425            error(lineno, 'invalid argument set token "{0}"'.format(t))
426        if t in flds:
427            error(lineno, 'duplicate argument "{0}"'.format(t))
428        flds.append(t)
429
430    if name in arguments:
431        error(lineno, 'duplicate argument set', name)
432    arguments[name] = Arguments(name, flds, extern)
433# end parse_arguments
434
435
436def lookup_field(lineno, name):
437    global fields
438    if name in fields:
439        return fields[name]
440    error(lineno, 'undefined field', name)
441
442
443def add_field(lineno, flds, new_name, f):
444    if new_name in flds:
445        error(lineno, 'duplicate field', new_name)
446    flds[new_name] = f
447    return flds
448
449
450def add_field_byname(lineno, flds, new_name, old_name):
451    return add_field(lineno, flds, new_name, lookup_field(lineno, old_name))
452
453
454def infer_argument_set(flds):
455    global arguments
456    global decode_function
457
458    for arg in arguments.values():
459        if eq_fields_for_args(flds, arg.fields):
460            return arg
461
462    name = decode_function + str(len(arguments))
463    arg = Arguments(name, flds.keys(), False)
464    arguments[name] = arg
465    return arg
466
467
468def infer_format(arg, fieldmask, flds):
469    global arguments
470    global formats
471    global decode_function
472
473    const_flds = {}
474    var_flds = {}
475    for n, c in flds.items():
476        if c is ConstField:
477            const_flds[n] = c
478        else:
479            var_flds[n] = c
480
481    # Look for an existing format with the same argument set and fields
482    for fmt in formats.values():
483        if arg and fmt.base != arg:
484            continue
485        if fieldmask != fmt.fieldmask:
486            continue
487        if not eq_fields_for_fmts(flds, fmt.fields):
488            continue
489        return (fmt, const_flds)
490
491    name = decode_function + '_Fmt_' + str(len(formats))
492    if not arg:
493        arg = infer_argument_set(flds)
494
495    fmt = Format(name, 0, arg, 0, 0, 0, fieldmask, var_flds)
496    formats[name] = fmt
497
498    return (fmt, const_flds)
499# end infer_format
500
501
502def parse_generic(lineno, is_format, name, toks):
503    """Parse one instruction format from TOKS at LINENO"""
504    global fields
505    global arguments
506    global formats
507    global patterns
508    global re_ident
509    global insnwidth
510    global insnmask
511
512    fixedmask = 0
513    fixedbits = 0
514    undefmask = 0
515    width = 0
516    flds = {}
517    arg = None
518    fmt = None
519    for t in toks:
520        # '&Foo' gives a format an explcit argument set.
521        if t[0] == '&':
522            tt = t[1:]
523            if arg:
524                error(lineno, 'multiple argument sets')
525            if tt in arguments:
526                arg = arguments[tt]
527            else:
528                error(lineno, 'undefined argument set', t)
529            continue
530
531        # '@Foo' gives a pattern an explicit format.
532        if t[0] == '@':
533            tt = t[1:]
534            if fmt:
535                error(lineno, 'multiple formats')
536            if tt in formats:
537                fmt = formats[tt]
538            else:
539                error(lineno, 'undefined format', t)
540            continue
541
542        # '%Foo' imports a field.
543        if t[0] == '%':
544            tt = t[1:]
545            flds = add_field_byname(lineno, flds, tt, tt)
546            continue
547
548        # 'Foo=%Bar' imports a field with a different name.
549        if re_fullmatch(re_ident + '=%' + re_ident, t):
550            (fname, iname) = t.split('=%')
551            flds = add_field_byname(lineno, flds, fname, iname)
552            continue
553
554        # 'Foo=number' sets an argument field to a constant value
555        if re_fullmatch(re_ident + '=[0-9]+', t):
556            (fname, value) = t.split('=')
557            value = int(value)
558            flds = add_field(lineno, flds, fname, ConstField(value))
559            continue
560
561        # Pattern of 0s, 1s, dots and dashes indicate required zeros,
562        # required ones, or dont-cares.
563        if re_fullmatch('[01.-]+', t):
564            shift = len(t)
565            fms = t.replace('0', '1')
566            fms = fms.replace('.', '0')
567            fms = fms.replace('-', '0')
568            fbs = t.replace('.', '0')
569            fbs = fbs.replace('-', '0')
570            ubm = t.replace('1', '0')
571            ubm = ubm.replace('.', '0')
572            ubm = ubm.replace('-', '1')
573            fms = int(fms, 2)
574            fbs = int(fbs, 2)
575            ubm = int(ubm, 2)
576            fixedbits = (fixedbits << shift) | fbs
577            fixedmask = (fixedmask << shift) | fms
578            undefmask = (undefmask << shift) | ubm
579        # Otherwise, fieldname:fieldwidth
580        elif re_fullmatch(re_ident + ':s?[0-9]+', t):
581            (fname, flen) = t.split(':')
582            sign = False
583            if flen[0] == 's':
584                sign = True
585                flen = flen[1:]
586            shift = int(flen, 10)
587            f = Field(sign, insnwidth - width - shift, shift)
588            flds = add_field(lineno, flds, fname, f)
589            fixedbits <<= shift
590            fixedmask <<= shift
591            undefmask <<= shift
592        else:
593            error(lineno, 'invalid token "{0}"'.format(t))
594        width += shift
595
596    # We should have filled in all of the bits of the instruction.
597    if not (is_format and width == 0) and width != insnwidth:
598        error(lineno, 'definition has {0} bits'.format(width))
599
600    # Do not check for fields overlaping fields; one valid usage
601    # is to be able to duplicate fields via import.
602    fieldmask = 0
603    for f in flds.values():
604        fieldmask |= f.mask
605
606    # Fix up what we've parsed to match either a format or a pattern.
607    if is_format:
608        # Formats cannot reference formats.
609        if fmt:
610            error(lineno, 'format referencing format')
611        # If an argument set is given, then there should be no fields
612        # without a place to store it.
613        if arg:
614            for f in flds.keys():
615                if f not in arg.fields:
616                    error(lineno, 'field {0} not in argument set {1}'
617                                  .format(f, arg.name))
618        else:
619            arg = infer_argument_set(flds)
620        if name in formats:
621            error(lineno, 'duplicate format name', name)
622        fmt = Format(name, lineno, arg, fixedbits, fixedmask,
623                     undefmask, fieldmask, flds)
624        formats[name] = fmt
625    else:
626        # Patterns can reference a format ...
627        if fmt:
628            # ... but not an argument simultaneously
629            if arg:
630                error(lineno, 'pattern specifies both format and argument set')
631            if fixedmask & fmt.fixedmask:
632                error(lineno, 'pattern fixed bits overlap format fixed bits')
633            fieldmask |= fmt.fieldmask
634            fixedbits |= fmt.fixedbits
635            fixedmask |= fmt.fixedmask
636            undefmask |= fmt.undefmask
637        else:
638            (fmt, flds) = infer_format(arg, fieldmask, flds)
639        arg = fmt.base
640        for f in flds.keys():
641            if f not in arg.fields:
642                error(lineno, 'field {0} not in argument set {1}'
643                              .format(f, arg.name))
644            if f in fmt.fields.keys():
645                error(lineno, 'field {0} set by format and pattern'.format(f))
646        for f in arg.fields:
647            if f not in flds.keys() and f not in fmt.fields.keys():
648                error(lineno, 'field {0} not initialized'.format(f))
649        pat = Pattern(name, lineno, fmt, fixedbits, fixedmask,
650                      undefmask, fieldmask, flds)
651        patterns.append(pat)
652
653    # Validate the masks that we have assembled.
654    if fieldmask & fixedmask:
655        error(lineno, 'fieldmask overlaps fixedmask (0x{0:08x} & 0x{1:08x})'
656                      .format(fieldmask, fixedmask))
657    if fieldmask & undefmask:
658        error(lineno, 'fieldmask overlaps undefmask (0x{0:08x} & 0x{1:08x})'
659                      .format(fieldmask, undefmask))
660    if fixedmask & undefmask:
661        error(lineno, 'fixedmask overlaps undefmask (0x{0:08x} & 0x{1:08x})'
662                      .format(fixedmask, undefmask))
663    if not is_format:
664        allbits = fieldmask | fixedmask | undefmask
665        if allbits != insnmask:
666            error(lineno, 'bits left unspecified (0x{0:08x})'
667                          .format(allbits ^ insnmask))
668# end parse_general
669
670
671def parse_file(f):
672    """Parse all of the patterns within a file"""
673
674    # Read all of the lines of the file.  Concatenate lines
675    # ending in backslash; discard empty lines and comments.
676    toks = []
677    lineno = 0
678    for line in f:
679        lineno += 1
680
681        # Discard comments
682        end = line.find('#')
683        if end >= 0:
684            line = line[:end]
685
686        t = line.split()
687        if len(toks) != 0:
688            # Next line after continuation
689            toks.extend(t)
690        elif len(t) == 0:
691            # Empty line
692            continue
693        else:
694            toks = t
695
696        # Continuation?
697        if toks[-1] == '\\':
698            toks.pop()
699            continue
700
701        if len(toks) < 2:
702            error(lineno, 'short line')
703
704        name = toks[0]
705        del toks[0]
706
707        # Determine the type of object needing to be parsed.
708        if name[0] == '%':
709            parse_field(lineno, name[1:], toks)
710        elif name[0] == '&':
711            parse_arguments(lineno, name[1:], toks)
712        elif name[0] == '@':
713            parse_generic(lineno, True, name[1:], toks)
714        else:
715            parse_generic(lineno, False, name, toks)
716        toks = []
717# end parse_file
718
719
720class Tree:
721    """Class representing a node in a decode tree"""
722
723    def __init__(self, fm, tm):
724        self.fixedmask = fm
725        self.thismask = tm
726        self.subs = []
727        self.base = None
728
729    def str1(self, i):
730        ind = str_indent(i)
731        r = '{0}{1:08x}'.format(ind, self.fixedmask)
732        if self.format:
733            r += ' ' + self.format.name
734        r += ' [\n'
735        for (b, s) in self.subs:
736            r += '{0}  {1:08x}:\n'.format(ind, b)
737            r += s.str1(i + 4) + '\n'
738        r += ind + ']'
739        return r
740
741    def __str__(self):
742        return self.str1(0)
743
744    def output_code(self, i, extracted, outerbits, outermask):
745        ind = str_indent(i)
746
747        # If we identified all nodes below have the same format,
748        # extract the fields now.
749        if not extracted and self.base:
750            output(ind, self.base.extract_name(),
751                   '(&u.f_', self.base.base.name, ', insn);\n')
752            extracted = True
753
754        # Attempt to aid the compiler in producing compact switch statements.
755        # If the bits in the mask are contiguous, extract them.
756        sh = is_contiguous(self.thismask)
757        if sh > 0:
758            # Propagate SH down into the local functions.
759            def str_switch(b, sh=sh):
760                return '(insn >> {0}) & 0x{1:x}'.format(sh, b >> sh)
761
762            def str_case(b, sh=sh):
763                return '0x{0:x}'.format(b >> sh)
764        else:
765            def str_switch(b):
766                return 'insn & 0x{0:08x}'.format(b)
767
768            def str_case(b):
769                return '0x{0:08x}'.format(b)
770
771        output(ind, 'switch (', str_switch(self.thismask), ') {\n')
772        for b, s in sorted(self.subs):
773            assert (self.thismask & ~s.fixedmask) == 0
774            innermask = outermask | self.thismask
775            innerbits = outerbits | b
776            output(ind, 'case ', str_case(b), ':\n')
777            output(ind, '    /* ',
778                   str_match_bits(innerbits, innermask), ' */\n')
779            s.output_code(i + 4, extracted, innerbits, innermask)
780        output(ind, '}\n')
781        output(ind, 'return false;\n')
782# end Tree
783
784
785def build_tree(pats, outerbits, outermask):
786    # Find the intersection of all remaining fixedmask.
787    innermask = ~outermask
788    for i in pats:
789        innermask &= i.fixedmask
790
791    if innermask == 0:
792        pnames = []
793        for p in pats:
794            pnames.append(p.name + ':' + p.file + ':' + str(p.lineno))
795        error_with_file(pats[0].file, pats[0].lineno,
796                        'overlapping patterns:', pnames)
797
798    fullmask = outermask | innermask
799
800    # Sort each element of pats into the bin selected by the mask.
801    bins = {}
802    for i in pats:
803        fb = i.fixedbits & innermask
804        if fb in bins:
805            bins[fb].append(i)
806        else:
807            bins[fb] = [i]
808
809    # We must recurse if any bin has more than one element or if
810    # the single element in the bin has not been fully matched.
811    t = Tree(fullmask, innermask)
812
813    for b, l in bins.items():
814        s = l[0]
815        if len(l) > 1 or s.fixedmask & ~fullmask != 0:
816            s = build_tree(l, b | outerbits, fullmask)
817        t.subs.append((b, s))
818
819    return t
820# end build_tree
821
822
823def prop_format(tree):
824    """Propagate Format objects into the decode tree"""
825
826    # Depth first search.
827    for (b, s) in tree.subs:
828        if isinstance(s, Tree):
829            prop_format(s)
830
831    # If all entries in SUBS have the same format, then
832    # propagate that into the tree.
833    f = None
834    for (b, s) in tree.subs:
835        if f is None:
836            f = s.base
837            if f is None:
838                return
839        if f is not s.base:
840            return
841    tree.base = f
842# end prop_format
843
844
845def main():
846    global arguments
847    global formats
848    global patterns
849    global translate_scope
850    global translate_prefix
851    global output_fd
852    global output_file
853    global input_file
854    global insnwidth
855    global insntype
856    global insnmask
857    global decode_function
858
859    decode_scope = 'static '
860
861    long_opts = ['decode=', 'translate=', 'output=', 'insnwidth=']
862    try:
863        (opts, args) = getopt.getopt(sys.argv[1:], 'o:w:', long_opts)
864    except getopt.GetoptError as err:
865        error(0, err)
866    for o, a in opts:
867        if o in ('-o', '--output'):
868            output_file = a
869        elif o == '--decode':
870            decode_function = a
871            decode_scope = ''
872        elif o == '--translate':
873            translate_prefix = a
874            translate_scope = ''
875        elif o in ('-w', '--insnwidth'):
876            insnwidth = int(a)
877            if insnwidth == 16:
878                insntype = 'uint16_t'
879                insnmask = 0xffff
880            elif insnwidth != 32:
881                error(0, 'cannot handle insns of width', insnwidth)
882        else:
883            assert False, 'unhandled option'
884
885    if len(args) < 1:
886        error(0, 'missing input file')
887    for filename in args:
888        input_file = filename
889        f = open(filename, 'r')
890        parse_file(f)
891        f.close()
892
893    t = build_tree(patterns, 0, 0)
894    prop_format(t)
895
896    if output_file:
897        output_fd = open(output_file, 'w')
898    else:
899        output_fd = sys.stdout
900
901    output_autogen()
902    for n in sorted(arguments.keys()):
903        f = arguments[n]
904        f.output_def()
905
906    # A single translate function can be invoked for different patterns.
907    # Make sure that the argument sets are the same, and declare the
908    # function only once.
909    out_pats = {}
910    for i in patterns:
911        if i.name in out_pats:
912            p = out_pats[i.name]
913            if i.base.base != p.base.base:
914                error(0, i.name, ' has conflicting argument sets')
915        else:
916            i.output_decl()
917            out_pats[i.name] = i
918    output('\n')
919
920    for n in sorted(formats.keys()):
921        f = formats[n]
922        f.output_extract()
923
924    output(decode_scope, 'bool ', decode_function,
925           '(DisasContext *ctx, ', insntype, ' insn)\n{\n')
926
927    i4 = str_indent(4)
928    output(i4, 'union {\n')
929    for n in sorted(arguments.keys()):
930        f = arguments[n]
931        output(i4, i4, f.struct_name(), ' f_', f.name, ';\n')
932    output(i4, '} u;\n\n')
933
934    t.output_code(4, False, 0, 0)
935
936    output('}\n')
937
938    if output_file:
939        output_fd.close()
940# end main
941
942
943if __name__ == '__main__':
944    main()
945