xref: /openbmc/qemu/scripts/decodetree.py (revision 88cd34ee)
1#!/usr/bin/env python3
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
30variablewidth = False
31fields = {}
32arguments = {}
33formats = {}
34patterns = []
35allpatterns = []
36anyextern = False
37
38translate_prefix = 'trans'
39translate_scope = 'static '
40input_file = ''
41output_file = None
42output_fd = None
43insntype = 'uint32_t'
44decode_function = 'decode'
45
46re_ident = '[a-zA-Z][a-zA-Z0-9_]*'
47
48
49def error_with_file(file, lineno, *args):
50    """Print an error message from file:line and args and exit."""
51    global output_file
52    global output_fd
53
54    if lineno:
55        r = '{0}:{1}: error:'.format(file, lineno)
56    elif input_file:
57        r = '{0}: error:'.format(file)
58    else:
59        r = 'error:'
60    for a in args:
61        r += ' ' + str(a)
62    r += '\n'
63    sys.stderr.write(r)
64    if output_file and output_fd:
65        output_fd.close()
66        os.remove(output_file)
67    exit(1)
68
69def error(lineno, *args):
70    error_with_file(input_file, lineno, args)
71
72def output(*args):
73    global output_fd
74    for a in args:
75        output_fd.write(a)
76
77
78if sys.version_info >= (3, 4):
79    re_fullmatch = re.fullmatch
80else:
81    def re_fullmatch(pat, str):
82        return re.match('^' + pat + '$', str)
83
84
85def output_autogen():
86    output('/* This file is autogenerated by scripts/decodetree.py.  */\n\n')
87
88
89def str_indent(c):
90    """Return a string with C spaces"""
91    return ' ' * c
92
93
94def str_fields(fields):
95    """Return a string uniquely identifing FIELDS"""
96    r = ''
97    for n in sorted(fields.keys()):
98        r += '_' + n
99    return r[1:]
100
101
102def str_match_bits(bits, mask):
103    """Return a string pretty-printing BITS/MASK"""
104    global insnwidth
105
106    i = 1 << (insnwidth - 1)
107    space = 0x01010100
108    r = ''
109    while i != 0:
110        if i & mask:
111            if i & bits:
112                r += '1'
113            else:
114                r += '0'
115        else:
116            r += '.'
117        if i & space:
118            r += ' '
119        i >>= 1
120    return r
121
122
123def is_pow2(x):
124    """Return true iff X is equal to a power of 2."""
125    return (x & (x - 1)) == 0
126
127
128def ctz(x):
129    """Return the number of times 2 factors into X."""
130    r = 0
131    while ((x >> r) & 1) == 0:
132        r += 1
133    return r
134
135
136def is_contiguous(bits):
137    shift = ctz(bits)
138    if is_pow2((bits >> shift) + 1):
139        return shift
140    else:
141        return -1
142
143
144def eq_fields_for_args(flds_a, flds_b):
145    if len(flds_a) != len(flds_b):
146        return False
147    for k, a in flds_a.items():
148        if k not in flds_b:
149            return False
150    return True
151
152
153def eq_fields_for_fmts(flds_a, flds_b):
154    if len(flds_a) != len(flds_b):
155        return False
156    for k, a in flds_a.items():
157        if k not in flds_b:
158            return False
159        b = flds_b[k]
160        if a.__class__ != b.__class__ or a != b:
161            return False
162    return True
163
164
165class Field:
166    """Class representing a simple instruction field"""
167    def __init__(self, sign, pos, len):
168        self.sign = sign
169        self.pos = pos
170        self.len = len
171        self.mask = ((1 << len) - 1) << pos
172
173    def __str__(self):
174        if self.sign:
175            s = 's'
176        else:
177            s = ''
178        return str(self.pos) + ':' + s + str(self.len)
179
180    def str_extract(self):
181        if self.sign:
182            extr = 'sextract32'
183        else:
184            extr = 'extract32'
185        return '{0}(insn, {1}, {2})'.format(extr, self.pos, self.len)
186
187    def __eq__(self, other):
188        return self.sign == other.sign and self.mask == other.mask
189
190    def __ne__(self, other):
191        return not self.__eq__(other)
192# end Field
193
194
195class MultiField:
196    """Class representing a compound instruction field"""
197    def __init__(self, subs, mask):
198        self.subs = subs
199        self.sign = subs[0].sign
200        self.mask = mask
201
202    def __str__(self):
203        return str(self.subs)
204
205    def str_extract(self):
206        ret = '0'
207        pos = 0
208        for f in reversed(self.subs):
209            if pos == 0:
210                ret = f.str_extract()
211            else:
212                ret = 'deposit32({0}, {1}, {2}, {3})' \
213                      .format(ret, pos, 32 - pos, f.str_extract())
214            pos += f.len
215        return ret
216
217    def __ne__(self, other):
218        if len(self.subs) != len(other.subs):
219            return True
220        for a, b in zip(self.subs, other.subs):
221            if a.__class__ != b.__class__ or a != b:
222                return True
223        return False
224
225    def __eq__(self, other):
226        return not self.__ne__(other)
227# end MultiField
228
229
230class ConstField:
231    """Class representing an argument field with constant value"""
232    def __init__(self, value):
233        self.value = value
234        self.mask = 0
235        self.sign = value < 0
236
237    def __str__(self):
238        return str(self.value)
239
240    def str_extract(self):
241        return str(self.value)
242
243    def __cmp__(self, other):
244        return self.value - other.value
245# end ConstField
246
247
248class FunctionField:
249    """Class representing a field passed through a function"""
250    def __init__(self, func, base):
251        self.mask = base.mask
252        self.sign = base.sign
253        self.base = base
254        self.func = func
255
256    def __str__(self):
257        return self.func + '(' + str(self.base) + ')'
258
259    def str_extract(self):
260        return self.func + '(ctx, ' + self.base.str_extract() + ')'
261
262    def __eq__(self, other):
263        return self.func == other.func and self.base == other.base
264
265    def __ne__(self, other):
266        return not self.__eq__(other)
267# end FunctionField
268
269
270class ParameterField:
271    """Class representing a pseudo-field read from a function"""
272    def __init__(self, func):
273        self.mask = 0
274        self.sign = 0
275        self.func = func
276
277    def __str__(self):
278        return self.func
279
280    def str_extract(self):
281        return self.func + '(ctx)'
282
283    def __eq__(self, other):
284        return self.func == other.func
285
286    def __ne__(self, other):
287        return not self.__eq__(other)
288# end ParameterField
289
290
291class Arguments:
292    """Class representing the extracted fields of a format"""
293    def __init__(self, nm, flds, extern):
294        self.name = nm
295        self.extern = extern
296        self.fields = sorted(flds)
297
298    def __str__(self):
299        return self.name + ' ' + str(self.fields)
300
301    def struct_name(self):
302        return 'arg_' + self.name
303
304    def output_def(self):
305        if not self.extern:
306            output('typedef struct {\n')
307            for n in self.fields:
308                output('    int ', n, ';\n')
309            output('} ', self.struct_name(), ';\n\n')
310# end Arguments
311
312
313class General:
314    """Common code between instruction formats and instruction patterns"""
315    def __init__(self, name, lineno, base, fixb, fixm, udfm, fldm, flds, w):
316        self.name = name
317        self.file = input_file
318        self.lineno = lineno
319        self.base = base
320        self.fixedbits = fixb
321        self.fixedmask = fixm
322        self.undefmask = udfm
323        self.fieldmask = fldm
324        self.fields = flds
325        self.width = w
326
327    def __str__(self):
328        return self.name + ' ' + str_match_bits(self.fixedbits, self.fixedmask)
329
330    def str1(self, i):
331        return str_indent(i) + self.__str__()
332# end General
333
334
335class Format(General):
336    """Class representing an instruction format"""
337
338    def extract_name(self):
339        global decode_function
340        return decode_function + '_extract_' + self.name
341
342    def output_extract(self):
343        output('static void ', self.extract_name(), '(DisasContext *ctx, ',
344               self.base.struct_name(), ' *a, ', insntype, ' insn)\n{\n')
345        for n, f in self.fields.items():
346            output('    a->', n, ' = ', f.str_extract(), ';\n')
347        output('}\n\n')
348# end Format
349
350
351class Pattern(General):
352    """Class representing an instruction pattern"""
353
354    def output_decl(self):
355        global translate_scope
356        global translate_prefix
357        output('typedef ', self.base.base.struct_name(),
358               ' arg_', self.name, ';\n')
359        output(translate_scope, 'bool ', translate_prefix, '_', self.name,
360               '(DisasContext *ctx, arg_', self.name, ' *a);\n')
361
362    def output_code(self, i, extracted, outerbits, outermask):
363        global translate_prefix
364        ind = str_indent(i)
365        arg = self.base.base.name
366        output(ind, '/* ', self.file, ':', str(self.lineno), ' */\n')
367        if not extracted:
368            output(ind, self.base.extract_name(),
369                   '(ctx, &u.f_', arg, ', insn);\n')
370        for n, f in self.fields.items():
371            output(ind, 'u.f_', arg, '.', n, ' = ', f.str_extract(), ';\n')
372        output(ind, 'if (', translate_prefix, '_', self.name,
373               '(ctx, &u.f_', arg, ')) return true;\n')
374# end Pattern
375
376
377class MultiPattern(General):
378    """Class representing an overlapping set of instruction patterns"""
379
380    def __init__(self, lineno, pats, fixb, fixm, udfm, w):
381        self.file = input_file
382        self.lineno = lineno
383        self.pats = pats
384        self.base = None
385        self.fixedbits = fixb
386        self.fixedmask = fixm
387        self.undefmask = udfm
388        self.width = w
389
390    def __str__(self):
391        r = "{"
392        for p in self.pats:
393           r = r + ' ' + str(p)
394        return r + "}"
395
396    def output_decl(self):
397        for p in self.pats:
398            p.output_decl()
399
400    def output_code(self, i, extracted, outerbits, outermask):
401        global translate_prefix
402        ind = str_indent(i)
403        for p in self.pats:
404            if outermask != p.fixedmask:
405                innermask = p.fixedmask & ~outermask
406                innerbits = p.fixedbits & ~outermask
407                output(ind, 'if ((insn & ',
408                       '0x{0:08x}) == 0x{1:08x}'.format(innermask, innerbits),
409                       ') {\n')
410                output(ind, '    /* ',
411                       str_match_bits(p.fixedbits, p.fixedmask), ' */\n')
412                p.output_code(i + 4, extracted, p.fixedbits, p.fixedmask)
413                output(ind, '}\n')
414            else:
415                p.output_code(i, extracted, p.fixedbits, p.fixedmask)
416#end MultiPattern
417
418
419def parse_field(lineno, name, toks):
420    """Parse one instruction field from TOKS at LINENO"""
421    global fields
422    global re_ident
423    global insnwidth
424
425    # A "simple" field will have only one entry;
426    # a "multifield" will have several.
427    subs = []
428    width = 0
429    func = None
430    for t in toks:
431        if re_fullmatch('!function=' + re_ident, t):
432            if func:
433                error(lineno, 'duplicate function')
434            func = t.split('=')
435            func = func[1]
436            continue
437
438        if re_fullmatch('[0-9]+:s[0-9]+', t):
439            # Signed field extract
440            subtoks = t.split(':s')
441            sign = True
442        elif re_fullmatch('[0-9]+:[0-9]+', t):
443            # Unsigned field extract
444            subtoks = t.split(':')
445            sign = False
446        else:
447            error(lineno, 'invalid field token "{0}"'.format(t))
448        po = int(subtoks[0])
449        le = int(subtoks[1])
450        if po + le > insnwidth:
451            error(lineno, 'field {0} too large'.format(t))
452        f = Field(sign, po, le)
453        subs.append(f)
454        width += le
455
456    if width > insnwidth:
457        error(lineno, 'field too large')
458    if len(subs) == 0:
459        if func:
460            f = ParameterField(func)
461        else:
462            error(lineno, 'field with no value')
463    else:
464        if len(subs) == 1:
465            f = subs[0]
466        else:
467            mask = 0
468            for s in subs:
469                if mask & s.mask:
470                    error(lineno, 'field components overlap')
471                mask |= s.mask
472            f = MultiField(subs, mask)
473        if func:
474            f = FunctionField(func, f)
475
476    if name in fields:
477        error(lineno, 'duplicate field', name)
478    fields[name] = f
479# end parse_field
480
481
482def parse_arguments(lineno, name, toks):
483    """Parse one argument set from TOKS at LINENO"""
484    global arguments
485    global re_ident
486    global anyextern
487
488    flds = []
489    extern = False
490    for t in toks:
491        if re_fullmatch('!extern', t):
492            extern = True
493            anyextern = True
494            continue
495        if not re_fullmatch(re_ident, t):
496            error(lineno, 'invalid argument set token "{0}"'.format(t))
497        if t in flds:
498            error(lineno, 'duplicate argument "{0}"'.format(t))
499        flds.append(t)
500
501    if name in arguments:
502        error(lineno, 'duplicate argument set', name)
503    arguments[name] = Arguments(name, flds, extern)
504# end parse_arguments
505
506
507def lookup_field(lineno, name):
508    global fields
509    if name in fields:
510        return fields[name]
511    error(lineno, 'undefined field', name)
512
513
514def add_field(lineno, flds, new_name, f):
515    if new_name in flds:
516        error(lineno, 'duplicate field', new_name)
517    flds[new_name] = f
518    return flds
519
520
521def add_field_byname(lineno, flds, new_name, old_name):
522    return add_field(lineno, flds, new_name, lookup_field(lineno, old_name))
523
524
525def infer_argument_set(flds):
526    global arguments
527    global decode_function
528
529    for arg in arguments.values():
530        if eq_fields_for_args(flds, arg.fields):
531            return arg
532
533    name = decode_function + str(len(arguments))
534    arg = Arguments(name, flds.keys(), False)
535    arguments[name] = arg
536    return arg
537
538
539def infer_format(arg, fieldmask, flds, width):
540    global arguments
541    global formats
542    global decode_function
543
544    const_flds = {}
545    var_flds = {}
546    for n, c in flds.items():
547        if c is ConstField:
548            const_flds[n] = c
549        else:
550            var_flds[n] = c
551
552    # Look for an existing format with the same argument set and fields
553    for fmt in formats.values():
554        if arg and fmt.base != arg:
555            continue
556        if fieldmask != fmt.fieldmask:
557            continue
558        if width != fmt.width:
559            continue
560        if not eq_fields_for_fmts(flds, fmt.fields):
561            continue
562        return (fmt, const_flds)
563
564    name = decode_function + '_Fmt_' + str(len(formats))
565    if not arg:
566        arg = infer_argument_set(flds)
567
568    fmt = Format(name, 0, arg, 0, 0, 0, fieldmask, var_flds, width)
569    formats[name] = fmt
570
571    return (fmt, const_flds)
572# end infer_format
573
574
575def parse_generic(lineno, is_format, name, toks):
576    """Parse one instruction format from TOKS at LINENO"""
577    global fields
578    global arguments
579    global formats
580    global patterns
581    global allpatterns
582    global re_ident
583    global insnwidth
584    global insnmask
585    global variablewidth
586
587    fixedmask = 0
588    fixedbits = 0
589    undefmask = 0
590    width = 0
591    flds = {}
592    arg = None
593    fmt = None
594    for t in toks:
595        # '&Foo' gives a format an explcit argument set.
596        if t[0] == '&':
597            tt = t[1:]
598            if arg:
599                error(lineno, 'multiple argument sets')
600            if tt in arguments:
601                arg = arguments[tt]
602            else:
603                error(lineno, 'undefined argument set', t)
604            continue
605
606        # '@Foo' gives a pattern an explicit format.
607        if t[0] == '@':
608            tt = t[1:]
609            if fmt:
610                error(lineno, 'multiple formats')
611            if tt in formats:
612                fmt = formats[tt]
613            else:
614                error(lineno, 'undefined format', t)
615            continue
616
617        # '%Foo' imports a field.
618        if t[0] == '%':
619            tt = t[1:]
620            flds = add_field_byname(lineno, flds, tt, tt)
621            continue
622
623        # 'Foo=%Bar' imports a field with a different name.
624        if re_fullmatch(re_ident + '=%' + re_ident, t):
625            (fname, iname) = t.split('=%')
626            flds = add_field_byname(lineno, flds, fname, iname)
627            continue
628
629        # 'Foo=number' sets an argument field to a constant value
630        if re_fullmatch(re_ident + '=[+-]?[0-9]+', t):
631            (fname, value) = t.split('=')
632            value = int(value)
633            flds = add_field(lineno, flds, fname, ConstField(value))
634            continue
635
636        # Pattern of 0s, 1s, dots and dashes indicate required zeros,
637        # required ones, or dont-cares.
638        if re_fullmatch('[01.-]+', t):
639            shift = len(t)
640            fms = t.replace('0', '1')
641            fms = fms.replace('.', '0')
642            fms = fms.replace('-', '0')
643            fbs = t.replace('.', '0')
644            fbs = fbs.replace('-', '0')
645            ubm = t.replace('1', '0')
646            ubm = ubm.replace('.', '0')
647            ubm = ubm.replace('-', '1')
648            fms = int(fms, 2)
649            fbs = int(fbs, 2)
650            ubm = int(ubm, 2)
651            fixedbits = (fixedbits << shift) | fbs
652            fixedmask = (fixedmask << shift) | fms
653            undefmask = (undefmask << shift) | ubm
654        # Otherwise, fieldname:fieldwidth
655        elif re_fullmatch(re_ident + ':s?[0-9]+', t):
656            (fname, flen) = t.split(':')
657            sign = False
658            if flen[0] == 's':
659                sign = True
660                flen = flen[1:]
661            shift = int(flen, 10)
662            if shift + width > insnwidth:
663                error(lineno, 'field {0} exceeds insnwidth'.format(fname))
664            f = Field(sign, insnwidth - width - shift, shift)
665            flds = add_field(lineno, flds, fname, f)
666            fixedbits <<= shift
667            fixedmask <<= shift
668            undefmask <<= shift
669        else:
670            error(lineno, 'invalid token "{0}"'.format(t))
671        width += shift
672
673    if variablewidth and width < insnwidth and width % 8 == 0:
674        shift = insnwidth - width
675        fixedbits <<= shift
676        fixedmask <<= shift
677        undefmask <<= shift
678        undefmask |= (1 << shift) - 1
679
680    # We should have filled in all of the bits of the instruction.
681    elif not (is_format and width == 0) and width != insnwidth:
682        error(lineno, 'definition has {0} bits'.format(width))
683
684    # Do not check for fields overlaping fields; one valid usage
685    # is to be able to duplicate fields via import.
686    fieldmask = 0
687    for f in flds.values():
688        fieldmask |= f.mask
689
690    # Fix up what we've parsed to match either a format or a pattern.
691    if is_format:
692        # Formats cannot reference formats.
693        if fmt:
694            error(lineno, 'format referencing format')
695        # If an argument set is given, then there should be no fields
696        # without a place to store it.
697        if arg:
698            for f in flds.keys():
699                if f not in arg.fields:
700                    error(lineno, 'field {0} not in argument set {1}'
701                                  .format(f, arg.name))
702        else:
703            arg = infer_argument_set(flds)
704        if name in formats:
705            error(lineno, 'duplicate format name', name)
706        fmt = Format(name, lineno, arg, fixedbits, fixedmask,
707                     undefmask, fieldmask, flds, width)
708        formats[name] = fmt
709    else:
710        # Patterns can reference a format ...
711        if fmt:
712            # ... but not an argument simultaneously
713            if arg:
714                error(lineno, 'pattern specifies both format and argument set')
715            if fixedmask & fmt.fixedmask:
716                error(lineno, 'pattern fixed bits overlap format fixed bits')
717            if width != fmt.width:
718                error(lineno, 'pattern uses format of different width')
719            fieldmask |= fmt.fieldmask
720            fixedbits |= fmt.fixedbits
721            fixedmask |= fmt.fixedmask
722            undefmask |= fmt.undefmask
723        else:
724            (fmt, flds) = infer_format(arg, fieldmask, flds, width)
725        arg = fmt.base
726        for f in flds.keys():
727            if f not in arg.fields:
728                error(lineno, 'field {0} not in argument set {1}'
729                              .format(f, arg.name))
730            if f in fmt.fields.keys():
731                error(lineno, 'field {0} set by format and pattern'.format(f))
732        for f in arg.fields:
733            if f not in flds.keys() and f not in fmt.fields.keys():
734                error(lineno, 'field {0} not initialized'.format(f))
735        pat = Pattern(name, lineno, fmt, fixedbits, fixedmask,
736                      undefmask, fieldmask, flds, width)
737        patterns.append(pat)
738        allpatterns.append(pat)
739
740    # Validate the masks that we have assembled.
741    if fieldmask & fixedmask:
742        error(lineno, 'fieldmask overlaps fixedmask (0x{0:08x} & 0x{1:08x})'
743                      .format(fieldmask, fixedmask))
744    if fieldmask & undefmask:
745        error(lineno, 'fieldmask overlaps undefmask (0x{0:08x} & 0x{1:08x})'
746                      .format(fieldmask, undefmask))
747    if fixedmask & undefmask:
748        error(lineno, 'fixedmask overlaps undefmask (0x{0:08x} & 0x{1:08x})'
749                      .format(fixedmask, undefmask))
750    if not is_format:
751        allbits = fieldmask | fixedmask | undefmask
752        if allbits != insnmask:
753            error(lineno, 'bits left unspecified (0x{0:08x})'
754                          .format(allbits ^ insnmask))
755# end parse_general
756
757def build_multi_pattern(lineno, pats):
758    """Validate the Patterns going into a MultiPattern."""
759    global patterns
760    global insnmask
761
762    if len(pats) < 2:
763        error(lineno, 'less than two patterns within braces')
764
765    fixedmask = insnmask
766    undefmask = insnmask
767
768    # Collect fixed/undefmask for all of the children.
769    # Move the defining lineno back to that of the first child.
770    for p in pats:
771        fixedmask &= p.fixedmask
772        undefmask &= p.undefmask
773        if p.lineno < lineno:
774            lineno = p.lineno
775
776    width = None
777    for p in pats:
778        if width is None:
779            width = p.width
780        elif width != p.width:
781            error(lineno, 'width mismatch in patterns within braces')
782
783    repeat = True
784    while repeat:
785        if fixedmask == 0:
786            error(lineno, 'no overlap in patterns within braces')
787        fixedbits = None
788        for p in pats:
789            thisbits = p.fixedbits & fixedmask
790            if fixedbits is None:
791                fixedbits = thisbits
792            elif fixedbits != thisbits:
793                fixedmask &= ~(fixedbits ^ thisbits)
794                break
795        else:
796            repeat = False
797
798    mp = MultiPattern(lineno, pats, fixedbits, fixedmask, undefmask, width)
799    patterns.append(mp)
800# end build_multi_pattern
801
802def parse_file(f):
803    """Parse all of the patterns within a file"""
804
805    global patterns
806
807    # Read all of the lines of the file.  Concatenate lines
808    # ending in backslash; discard empty lines and comments.
809    toks = []
810    lineno = 0
811    nesting = 0
812    saved_pats = []
813
814    for line in f:
815        lineno += 1
816
817        # Expand and strip spaces, to find indent.
818        line = line.rstrip()
819        line = line.expandtabs()
820        len1 = len(line)
821        line = line.lstrip()
822        len2 = len(line)
823
824        # Discard comments
825        end = line.find('#')
826        if end >= 0:
827            line = line[:end]
828
829        t = line.split()
830        if len(toks) != 0:
831            # Next line after continuation
832            toks.extend(t)
833        else:
834            # Allow completely blank lines.
835            if len1 == 0:
836                continue
837            indent = len1 - len2
838            # Empty line due to comment.
839            if len(t) == 0:
840                # Indentation must be correct, even for comment lines.
841                if indent != nesting:
842                    error(lineno, 'indentation ', indent, ' != ', nesting)
843                continue
844            start_lineno = lineno
845            toks = t
846
847        # Continuation?
848        if toks[-1] == '\\':
849            toks.pop()
850            continue
851
852        name = toks[0]
853        del toks[0]
854
855        # End nesting?
856        if name == '}':
857            if nesting == 0:
858                error(start_lineno, 'mismatched close brace')
859            if len(toks) != 0:
860                error(start_lineno, 'extra tokens after close brace')
861            nesting -= 2
862            if indent != nesting:
863                error(start_lineno, 'indentation ', indent, ' != ', nesting)
864            pats = patterns
865            patterns = saved_pats.pop()
866            build_multi_pattern(lineno, pats)
867            toks = []
868            continue
869
870        # Everything else should have current indentation.
871        if indent != nesting:
872            error(start_lineno, 'indentation ', indent, ' != ', nesting)
873
874        # Start nesting?
875        if name == '{':
876            if len(toks) != 0:
877                error(start_lineno, 'extra tokens after open brace')
878            saved_pats.append(patterns)
879            patterns = []
880            nesting += 2
881            toks = []
882            continue
883
884        # Determine the type of object needing to be parsed.
885        if name[0] == '%':
886            parse_field(start_lineno, name[1:], toks)
887        elif name[0] == '&':
888            parse_arguments(start_lineno, name[1:], toks)
889        elif name[0] == '@':
890            parse_generic(start_lineno, True, name[1:], toks)
891        else:
892            parse_generic(start_lineno, False, name, toks)
893        toks = []
894# end parse_file
895
896
897class Tree:
898    """Class representing a node in a decode tree"""
899
900    def __init__(self, fm, tm):
901        self.fixedmask = fm
902        self.thismask = tm
903        self.subs = []
904        self.base = None
905
906    def str1(self, i):
907        ind = str_indent(i)
908        r = '{0}{1:08x}'.format(ind, self.fixedmask)
909        if self.format:
910            r += ' ' + self.format.name
911        r += ' [\n'
912        for (b, s) in self.subs:
913            r += '{0}  {1:08x}:\n'.format(ind, b)
914            r += s.str1(i + 4) + '\n'
915        r += ind + ']'
916        return r
917
918    def __str__(self):
919        return self.str1(0)
920
921    def output_code(self, i, extracted, outerbits, outermask):
922        ind = str_indent(i)
923
924        # If we identified all nodes below have the same format,
925        # extract the fields now.
926        if not extracted and self.base:
927            output(ind, self.base.extract_name(),
928                   '(ctx, &u.f_', self.base.base.name, ', insn);\n')
929            extracted = True
930
931        # Attempt to aid the compiler in producing compact switch statements.
932        # If the bits in the mask are contiguous, extract them.
933        sh = is_contiguous(self.thismask)
934        if sh > 0:
935            # Propagate SH down into the local functions.
936            def str_switch(b, sh=sh):
937                return '(insn >> {0}) & 0x{1:x}'.format(sh, b >> sh)
938
939            def str_case(b, sh=sh):
940                return '0x{0:x}'.format(b >> sh)
941        else:
942            def str_switch(b):
943                return 'insn & 0x{0:08x}'.format(b)
944
945            def str_case(b):
946                return '0x{0:08x}'.format(b)
947
948        output(ind, 'switch (', str_switch(self.thismask), ') {\n')
949        for b, s in sorted(self.subs):
950            assert (self.thismask & ~s.fixedmask) == 0
951            innermask = outermask | self.thismask
952            innerbits = outerbits | b
953            output(ind, 'case ', str_case(b), ':\n')
954            output(ind, '    /* ',
955                   str_match_bits(innerbits, innermask), ' */\n')
956            s.output_code(i + 4, extracted, innerbits, innermask)
957            output(ind, '    return false;\n')
958        output(ind, '}\n')
959# end Tree
960
961
962def build_tree(pats, outerbits, outermask):
963    # Find the intersection of all remaining fixedmask.
964    innermask = ~outermask & insnmask
965    for i in pats:
966        innermask &= i.fixedmask
967
968    if innermask == 0:
969        text = 'overlapping patterns:'
970        for p in pats:
971            text += '\n' + p.file + ':' + str(p.lineno) + ': ' + str(p)
972        error_with_file(pats[0].file, pats[0].lineno, text)
973
974    fullmask = outermask | innermask
975
976    # Sort each element of pats into the bin selected by the mask.
977    bins = {}
978    for i in pats:
979        fb = i.fixedbits & innermask
980        if fb in bins:
981            bins[fb].append(i)
982        else:
983            bins[fb] = [i]
984
985    # We must recurse if any bin has more than one element or if
986    # the single element in the bin has not been fully matched.
987    t = Tree(fullmask, innermask)
988
989    for b, l in bins.items():
990        s = l[0]
991        if len(l) > 1 or s.fixedmask & ~fullmask != 0:
992            s = build_tree(l, b | outerbits, fullmask)
993        t.subs.append((b, s))
994
995    return t
996# end build_tree
997
998
999class SizeTree:
1000    """Class representing a node in a size decode tree"""
1001
1002    def __init__(self, m, w):
1003        self.mask = m
1004        self.subs = []
1005        self.base = None
1006        self.width = w
1007
1008    def str1(self, i):
1009        ind = str_indent(i)
1010        r = '{0}{1:08x}'.format(ind, self.mask)
1011        r += ' [\n'
1012        for (b, s) in self.subs:
1013            r += '{0}  {1:08x}:\n'.format(ind, b)
1014            r += s.str1(i + 4) + '\n'
1015        r += ind + ']'
1016        return r
1017
1018    def __str__(self):
1019        return self.str1(0)
1020
1021    def output_code(self, i, extracted, outerbits, outermask):
1022        ind = str_indent(i)
1023
1024        # If we need to load more bytes to test, do so now.
1025        if extracted < self.width:
1026            output(ind, 'insn = ', decode_function,
1027                   '_load_bytes(ctx, insn, {0}, {1});\n'
1028                   .format(extracted / 8, self.width / 8));
1029            extracted = self.width
1030
1031        # Attempt to aid the compiler in producing compact switch statements.
1032        # If the bits in the mask are contiguous, extract them.
1033        sh = is_contiguous(self.mask)
1034        if sh > 0:
1035            # Propagate SH down into the local functions.
1036            def str_switch(b, sh=sh):
1037                return '(insn >> {0}) & 0x{1:x}'.format(sh, b >> sh)
1038
1039            def str_case(b, sh=sh):
1040                return '0x{0:x}'.format(b >> sh)
1041        else:
1042            def str_switch(b):
1043                return 'insn & 0x{0:08x}'.format(b)
1044
1045            def str_case(b):
1046                return '0x{0:08x}'.format(b)
1047
1048        output(ind, 'switch (', str_switch(self.mask), ') {\n')
1049        for b, s in sorted(self.subs):
1050            innermask = outermask | self.mask
1051            innerbits = outerbits | b
1052            output(ind, 'case ', str_case(b), ':\n')
1053            output(ind, '    /* ',
1054                   str_match_bits(innerbits, innermask), ' */\n')
1055            s.output_code(i + 4, extracted, innerbits, innermask)
1056        output(ind, '}\n')
1057        output(ind, 'return insn;\n')
1058# end SizeTree
1059
1060class SizeLeaf:
1061    """Class representing a leaf node in a size decode tree"""
1062
1063    def __init__(self, m, w):
1064        self.mask = m
1065        self.width = w
1066
1067    def str1(self, i):
1068        ind = str_indent(i)
1069        return '{0}{1:08x}'.format(ind, self.mask)
1070
1071    def __str__(self):
1072        return self.str1(0)
1073
1074    def output_code(self, i, extracted, outerbits, outermask):
1075        global decode_function
1076        ind = str_indent(i)
1077
1078        # If we need to load more bytes, do so now.
1079        if extracted < self.width:
1080            output(ind, 'insn = ', decode_function,
1081                   '_load_bytes(ctx, insn, {0}, {1});\n'
1082                   .format(extracted / 8, self.width / 8));
1083            extracted = self.width
1084        output(ind, 'return insn;\n')
1085# end SizeLeaf
1086
1087
1088def build_size_tree(pats, width, outerbits, outermask):
1089    global insnwidth
1090
1091    # Collect the mask of bits that are fixed in this width
1092    innermask = 0xff << (insnwidth - width)
1093    innermask &= ~outermask
1094    minwidth = None
1095    onewidth = True
1096    for i in pats:
1097        innermask &= i.fixedmask
1098        if minwidth is None:
1099            minwidth = i.width
1100        elif minwidth != i.width:
1101            onewidth = False;
1102            if minwidth < i.width:
1103                minwidth = i.width
1104
1105    if onewidth:
1106        return SizeLeaf(innermask, minwidth)
1107
1108    if innermask == 0:
1109        if width < minwidth:
1110            return build_size_tree(pats, width + 8, outerbits, outermask)
1111
1112        pnames = []
1113        for p in pats:
1114            pnames.append(p.name + ':' + p.file + ':' + str(p.lineno))
1115        error_with_file(pats[0].file, pats[0].lineno,
1116                        'overlapping patterns size {0}:'.format(width), pnames)
1117
1118    bins = {}
1119    for i in pats:
1120        fb = i.fixedbits & innermask
1121        if fb in bins:
1122            bins[fb].append(i)
1123        else:
1124            bins[fb] = [i]
1125
1126    fullmask = outermask | innermask
1127    lens = sorted(bins.keys())
1128    if len(lens) == 1:
1129        b = lens[0]
1130        return build_size_tree(bins[b], width + 8, b | outerbits, fullmask)
1131
1132    r = SizeTree(innermask, width)
1133    for b, l in bins.items():
1134        s = build_size_tree(l, width, b | outerbits, fullmask)
1135        r.subs.append((b, s))
1136    return r
1137# end build_size_tree
1138
1139
1140def prop_format(tree):
1141    """Propagate Format objects into the decode tree"""
1142
1143    # Depth first search.
1144    for (b, s) in tree.subs:
1145        if isinstance(s, Tree):
1146            prop_format(s)
1147
1148    # If all entries in SUBS have the same format, then
1149    # propagate that into the tree.
1150    f = None
1151    for (b, s) in tree.subs:
1152        if f is None:
1153            f = s.base
1154            if f is None:
1155                return
1156        if f is not s.base:
1157            return
1158    tree.base = f
1159# end prop_format
1160
1161
1162def prop_size(tree):
1163    """Propagate minimum widths up the decode size tree"""
1164
1165    if isinstance(tree, SizeTree):
1166        min = None
1167        for (b, s) in tree.subs:
1168            width = prop_size(s)
1169            if min is None or min > width:
1170                min = width
1171        assert min >= tree.width
1172        tree.width = min
1173    else:
1174        min = tree.width
1175    return min
1176# end prop_size
1177
1178
1179def main():
1180    global arguments
1181    global formats
1182    global patterns
1183    global allpatterns
1184    global translate_scope
1185    global translate_prefix
1186    global output_fd
1187    global output_file
1188    global input_file
1189    global insnwidth
1190    global insntype
1191    global insnmask
1192    global decode_function
1193    global variablewidth
1194    global anyextern
1195
1196    decode_scope = 'static '
1197
1198    long_opts = ['decode=', 'translate=', 'output=', 'insnwidth=',
1199                 'static-decode=', 'varinsnwidth=']
1200    try:
1201        (opts, args) = getopt.getopt(sys.argv[1:], 'o:vw:', long_opts)
1202    except getopt.GetoptError as err:
1203        error(0, err)
1204    for o, a in opts:
1205        if o in ('-o', '--output'):
1206            output_file = a
1207        elif o == '--decode':
1208            decode_function = a
1209            decode_scope = ''
1210        elif o == '--static-decode':
1211            decode_function = a
1212        elif o == '--translate':
1213            translate_prefix = a
1214            translate_scope = ''
1215        elif o in ('-w', '--insnwidth', '--varinsnwidth'):
1216            if o == '--varinsnwidth':
1217                variablewidth = True
1218            insnwidth = int(a)
1219            if insnwidth == 16:
1220                insntype = 'uint16_t'
1221                insnmask = 0xffff
1222            elif insnwidth != 32:
1223                error(0, 'cannot handle insns of width', insnwidth)
1224        else:
1225            assert False, 'unhandled option'
1226
1227    if len(args) < 1:
1228        error(0, 'missing input file')
1229    for filename in args:
1230        input_file = filename
1231        f = open(filename, 'r')
1232        parse_file(f)
1233        f.close()
1234
1235    if variablewidth:
1236        stree = build_size_tree(patterns, 8, 0, 0)
1237        prop_size(stree)
1238
1239    dtree = build_tree(patterns, 0, 0)
1240    prop_format(dtree)
1241
1242    if output_file:
1243        output_fd = open(output_file, 'w')
1244    else:
1245        output_fd = sys.stdout
1246
1247    output_autogen()
1248    for n in sorted(arguments.keys()):
1249        f = arguments[n]
1250        f.output_def()
1251
1252    # A single translate function can be invoked for different patterns.
1253    # Make sure that the argument sets are the same, and declare the
1254    # function only once.
1255    #
1256    # If we're sharing formats, we're likely also sharing trans_* functions,
1257    # but we can't tell which ones.  Prevent issues from the compiler by
1258    # suppressing redundant declaration warnings.
1259    if anyextern:
1260        output("#ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE\n",
1261               "# pragma GCC diagnostic push\n",
1262               "# pragma GCC diagnostic ignored \"-Wredundant-decls\"\n",
1263               "# ifdef __clang__\n"
1264               "#  pragma GCC diagnostic ignored \"-Wtypedef-redefinition\"\n",
1265               "# endif\n",
1266               "#endif\n\n")
1267
1268    out_pats = {}
1269    for i in allpatterns:
1270        if i.name in out_pats:
1271            p = out_pats[i.name]
1272            if i.base.base != p.base.base:
1273                error(0, i.name, ' has conflicting argument sets')
1274        else:
1275            i.output_decl()
1276            out_pats[i.name] = i
1277    output('\n')
1278
1279    if anyextern:
1280        output("#ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE\n",
1281               "# pragma GCC diagnostic pop\n",
1282               "#endif\n\n")
1283
1284    for n in sorted(formats.keys()):
1285        f = formats[n]
1286        f.output_extract()
1287
1288    output(decode_scope, 'bool ', decode_function,
1289           '(DisasContext *ctx, ', insntype, ' insn)\n{\n')
1290
1291    i4 = str_indent(4)
1292
1293    if len(allpatterns) != 0:
1294        output(i4, 'union {\n')
1295        for n in sorted(arguments.keys()):
1296            f = arguments[n]
1297            output(i4, i4, f.struct_name(), ' f_', f.name, ';\n')
1298        output(i4, '} u;\n\n')
1299        dtree.output_code(4, False, 0, 0)
1300
1301    output(i4, 'return false;\n')
1302    output('}\n')
1303
1304    if variablewidth:
1305        output('\n', decode_scope, insntype, ' ', decode_function,
1306               '_load(DisasContext *ctx)\n{\n',
1307               '    ', insntype, ' insn = 0;\n\n')
1308        stree.output_code(4, 0, 0, 0)
1309        output('}\n')
1310
1311    if output_file:
1312        output_fd.close()
1313# end main
1314
1315
1316if __name__ == '__main__':
1317    main()
1318