| #!/usr/bin/env python3 |
| # Copyright (c) 2018 Linaro Limited |
| # |
| # This library is free software; you can redistribute it and/or |
| # modify it under the terms of the GNU Lesser General Public |
| # License as published by the Free Software Foundation; either |
| # version 2.1 of the License, or (at your option) any later version. |
| # |
| # This library is distributed in the hope that it will be useful, |
| # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| # Lesser General Public License for more details. |
| # |
| # You should have received a copy of the GNU Lesser General Public |
| # License along with this library; if not, see <http://www.gnu.org/licenses/>. |
| # |
| |
| # |
| # Generate a decoding tree from a specification file. |
| # See the syntax and semantics in docs/devel/decodetree.rst. |
| # |
| |
| import io |
| import os |
| import re |
| import sys |
| import getopt |
| |
| insnwidth = 32 |
| bitop_width = 32 |
| insnmask = 0xffffffff |
| variablewidth = False |
| fields = {} |
| arguments = {} |
| formats = {} |
| allpatterns = [] |
| anyextern = False |
| |
| translate_prefix = 'trans' |
| translate_scope = 'static ' |
| input_file = '' |
| output_file = None |
| output_fd = None |
| insntype = 'uint32_t' |
| decode_function = 'decode' |
| |
| # An identifier for C. |
| re_C_ident = '[a-zA-Z][a-zA-Z0-9_]*' |
| |
| # Identifiers for Arguments, Fields, Formats and Patterns. |
| re_arg_ident = '&[a-zA-Z0-9_]*' |
| re_fld_ident = '%[a-zA-Z0-9_]*' |
| re_fmt_ident = '@[a-zA-Z0-9_]*' |
| re_pat_ident = '[a-zA-Z0-9_]*' |
| |
| def error_with_file(file, lineno, *args): |
| """Print an error message from file:line and args and exit.""" |
| global output_file |
| global output_fd |
| |
| prefix = '' |
| if file: |
| prefix += f'{file}:' |
| if lineno: |
| prefix += f'{lineno}:' |
| if prefix: |
| prefix += ' ' |
| print(prefix, end='error: ', file=sys.stderr) |
| print(*args, file=sys.stderr) |
| |
| if output_file and output_fd: |
| output_fd.close() |
| os.remove(output_file) |
| exit(1) |
| # end error_with_file |
| |
| |
| def error(lineno, *args): |
| error_with_file(input_file, lineno, *args) |
| # end error |
| |
| |
| def output(*args): |
| global output_fd |
| for a in args: |
| output_fd.write(a) |
| |
| |
| def output_autogen(): |
| output('/* This file is autogenerated by scripts/decodetree.py. */\n\n') |
| |
| |
| def str_indent(c): |
| """Return a string with C spaces""" |
| return ' ' * c |
| |
| |
| def str_fields(fields): |
| """Return a string uniquely identifying FIELDS""" |
| r = '' |
| for n in sorted(fields.keys()): |
| r += '_' + n |
| return r[1:] |
| |
| |
| def whex(val): |
| """Return a hex string for val padded for insnwidth""" |
| global insnwidth |
| return f'0x{val:0{insnwidth // 4}x}' |
| |
| |
| def whexC(val): |
| """Return a hex string for val padded for insnwidth, |
| and with the proper suffix for a C constant.""" |
| suffix = '' |
| if val >= 0x100000000: |
| suffix = 'ull' |
| elif val >= 0x80000000: |
| suffix = 'u' |
| return whex(val) + suffix |
| |
| |
| def str_match_bits(bits, mask): |
| """Return a string pretty-printing BITS/MASK""" |
| global insnwidth |
| |
| i = 1 << (insnwidth - 1) |
| space = 0x01010100 |
| r = '' |
| while i != 0: |
| if i & mask: |
| if i & bits: |
| r += '1' |
| else: |
| r += '0' |
| else: |
| r += '.' |
| if i & space: |
| r += ' ' |
| i >>= 1 |
| return r |
| |
| |
| def is_pow2(x): |
| """Return true iff X is equal to a power of 2.""" |
| return (x & (x - 1)) == 0 |
| |
| |
| def ctz(x): |
| """Return the number of times 2 factors into X.""" |
| assert x != 0 |
| r = 0 |
| while ((x >> r) & 1) == 0: |
| r += 1 |
| return r |
| |
| |
| def is_contiguous(bits): |
| if bits == 0: |
| return -1 |
| shift = ctz(bits) |
| if is_pow2((bits >> shift) + 1): |
| return shift |
| else: |
| return -1 |
| |
| |
| def eq_fields_for_args(flds_a, arg): |
| if len(flds_a) != len(arg.fields): |
| return False |
| # Only allow inference on default types |
| for t in arg.types: |
| if t != 'int': |
| return False |
| for k, a in flds_a.items(): |
| if k not in arg.fields: |
| return False |
| return True |
| |
| |
| def eq_fields_for_fmts(flds_a, flds_b): |
| if len(flds_a) != len(flds_b): |
| return False |
| for k, a in flds_a.items(): |
| if k not in flds_b: |
| return False |
| b = flds_b[k] |
| if a.__class__ != b.__class__ or a != b: |
| return False |
| return True |
| |
| |
| class Field: |
| """Class representing a simple instruction field""" |
| def __init__(self, sign, pos, len): |
| self.sign = sign |
| self.pos = pos |
| self.len = len |
| self.mask = ((1 << len) - 1) << pos |
| |
| def __str__(self): |
| if self.sign: |
| s = 's' |
| else: |
| s = '' |
| return str(self.pos) + ':' + s + str(self.len) |
| |
| def str_extract(self): |
| global bitop_width |
| s = 's' if self.sign else '' |
| return f'{s}extract{bitop_width}(insn, {self.pos}, {self.len})' |
| |
| def __eq__(self, other): |
| return self.sign == other.sign and self.mask == other.mask |
| |
| def __ne__(self, other): |
| return not self.__eq__(other) |
| # end Field |
| |
| |
| class MultiField: |
| """Class representing a compound instruction field""" |
| def __init__(self, subs, mask): |
| self.subs = subs |
| self.sign = subs[0].sign |
| self.mask = mask |
| |
| def __str__(self): |
| return str(self.subs) |
| |
| def str_extract(self): |
| global bitop_width |
| ret = '0' |
| pos = 0 |
| for f in reversed(self.subs): |
| ext = f.str_extract() |
| if pos == 0: |
| ret = ext |
| else: |
| ret = f'deposit{bitop_width}({ret}, {pos}, {bitop_width - pos}, {ext})' |
| pos += f.len |
| return ret |
| |
| def __ne__(self, other): |
| if len(self.subs) != len(other.subs): |
| return True |
| for a, b in zip(self.subs, other.subs): |
| if a.__class__ != b.__class__ or a != b: |
| return True |
| return False |
| |
| def __eq__(self, other): |
| return not self.__ne__(other) |
| # end MultiField |
| |
| |
| class ConstField: |
| """Class representing an argument field with constant value""" |
| def __init__(self, value): |
| self.value = value |
| self.mask = 0 |
| self.sign = value < 0 |
| |
| def __str__(self): |
| return str(self.value) |
| |
| def str_extract(self): |
| return str(self.value) |
| |
| def __cmp__(self, other): |
| return self.value - other.value |
| # end ConstField |
| |
| |
| class FunctionField: |
| """Class representing a field passed through a function""" |
| def __init__(self, func, base): |
| self.mask = base.mask |
| self.sign = base.sign |
| self.base = base |
| self.func = func |
| |
| def __str__(self): |
| return self.func + '(' + str(self.base) + ')' |
| |
| def str_extract(self): |
| return self.func + '(ctx, ' + self.base.str_extract() + ')' |
| |
| def __eq__(self, other): |
| return self.func == other.func and self.base == other.base |
| |
| def __ne__(self, other): |
| return not self.__eq__(other) |
| # end FunctionField |
| |
| |
| class ParameterField: |
| """Class representing a pseudo-field read from a function""" |
| def __init__(self, func): |
| self.mask = 0 |
| self.sign = 0 |
| self.func = func |
| |
| def __str__(self): |
| return self.func |
| |
| def str_extract(self): |
| return self.func + '(ctx)' |
| |
| def __eq__(self, other): |
| return self.func == other.func |
| |
| def __ne__(self, other): |
| return not self.__eq__(other) |
| # end ParameterField |
| |
| |
| class Arguments: |
| """Class representing the extracted fields of a format""" |
| def __init__(self, nm, flds, types, extern): |
| self.name = nm |
| self.extern = extern |
| self.fields = flds |
| self.types = types |
| |
| def __str__(self): |
| return self.name + ' ' + str(self.fields) |
| |
| def struct_name(self): |
| return 'arg_' + self.name |
| |
| def output_def(self): |
| if not self.extern: |
| output('typedef struct {\n') |
| for (n, t) in zip(self.fields, self.types): |
| output(f' {t} {n};\n') |
| output('} ', self.struct_name(), ';\n\n') |
| # end Arguments |
| |
| |
| class General: |
| """Common code between instruction formats and instruction patterns""" |
| def __init__(self, name, lineno, base, fixb, fixm, udfm, fldm, flds, w): |
| self.name = name |
| self.file = input_file |
| self.lineno = lineno |
| self.base = base |
| self.fixedbits = fixb |
| self.fixedmask = fixm |
| self.undefmask = udfm |
| self.fieldmask = fldm |
| self.fields = flds |
| self.width = w |
| |
| def __str__(self): |
| return self.name + ' ' + str_match_bits(self.fixedbits, self.fixedmask) |
| |
| def str1(self, i): |
| return str_indent(i) + self.__str__() |
| # end General |
| |
| |
| class Format(General): |
| """Class representing an instruction format""" |
| |
| def extract_name(self): |
| global decode_function |
| return decode_function + '_extract_' + self.name |
| |
| def output_extract(self): |
| output('static void ', self.extract_name(), '(DisasContext *ctx, ', |
| self.base.struct_name(), ' *a, ', insntype, ' insn)\n{\n') |
| for n, f in self.fields.items(): |
| output(' a->', n, ' = ', f.str_extract(), ';\n') |
| output('}\n\n') |
| # end Format |
| |
| |
| class Pattern(General): |
| """Class representing an instruction pattern""" |
| |
| def output_decl(self): |
| global translate_scope |
| global translate_prefix |
| output('typedef ', self.base.base.struct_name(), |
| ' arg_', self.name, ';\n') |
| output(translate_scope, 'bool ', translate_prefix, '_', self.name, |
| '(DisasContext *ctx, arg_', self.name, ' *a);\n') |
| |
| def output_code(self, i, extracted, outerbits, outermask): |
| global translate_prefix |
| ind = str_indent(i) |
| arg = self.base.base.name |
| output(ind, '/* ', self.file, ':', str(self.lineno), ' */\n') |
| if not extracted: |
| output(ind, self.base.extract_name(), |
| '(ctx, &u.f_', arg, ', insn);\n') |
| for n, f in self.fields.items(): |
| output(ind, 'u.f_', arg, '.', n, ' = ', f.str_extract(), ';\n') |
| output(ind, 'if (', translate_prefix, '_', self.name, |
| '(ctx, &u.f_', arg, ')) return true;\n') |
| |
| # Normal patterns do not have children. |
| def build_tree(self): |
| return |
| def prop_masks(self): |
| return |
| def prop_format(self): |
| return |
| def prop_width(self): |
| return |
| |
| # end Pattern |
| |
| |
| class MultiPattern(General): |
| """Class representing a set of instruction patterns""" |
| |
| def __init__(self, lineno): |
| self.file = input_file |
| self.lineno = lineno |
| self.pats = [] |
| self.base = None |
| self.fixedbits = 0 |
| self.fixedmask = 0 |
| self.undefmask = 0 |
| self.width = None |
| |
| def __str__(self): |
| r = 'group' |
| if self.fixedbits is not None: |
| r += ' ' + str_match_bits(self.fixedbits, self.fixedmask) |
| return r |
| |
| def output_decl(self): |
| for p in self.pats: |
| p.output_decl() |
| |
| def prop_masks(self): |
| global insnmask |
| |
| fixedmask = insnmask |
| undefmask = insnmask |
| |
| # Collect fixedmask/undefmask for all of the children. |
| for p in self.pats: |
| p.prop_masks() |
| fixedmask &= p.fixedmask |
| undefmask &= p.undefmask |
| |
| # Widen fixedmask until all fixedbits match |
| repeat = True |
| fixedbits = 0 |
| while repeat and fixedmask != 0: |
| fixedbits = None |
| for p in self.pats: |
| thisbits = p.fixedbits & fixedmask |
| if fixedbits is None: |
| fixedbits = thisbits |
| elif fixedbits != thisbits: |
| fixedmask &= ~(fixedbits ^ thisbits) |
| break |
| else: |
| repeat = False |
| |
| self.fixedbits = fixedbits |
| self.fixedmask = fixedmask |
| self.undefmask = undefmask |
| |
| def build_tree(self): |
| for p in self.pats: |
| p.build_tree() |
| |
| def prop_format(self): |
| for p in self.pats: |
| p.build_tree() |
| |
| def prop_width(self): |
| width = None |
| for p in self.pats: |
| p.prop_width() |
| if width is None: |
| width = p.width |
| elif width != p.width: |
| error_with_file(self.file, self.lineno, |
| 'width mismatch in patterns within braces') |
| self.width = width |
| |
| # end MultiPattern |
| |
| |
| class IncMultiPattern(MultiPattern): |
| """Class representing an overlapping set of instruction patterns""" |
| |
| def output_code(self, i, extracted, outerbits, outermask): |
| global translate_prefix |
| ind = str_indent(i) |
| for p in self.pats: |
| if outermask != p.fixedmask: |
| innermask = p.fixedmask & ~outermask |
| innerbits = p.fixedbits & ~outermask |
| output(ind, f'if ((insn & {whexC(innermask)}) == {whexC(innerbits)}) {{\n') |
| output(ind, f' /* {str_match_bits(p.fixedbits, p.fixedmask)} */\n') |
| p.output_code(i + 4, extracted, p.fixedbits, p.fixedmask) |
| output(ind, '}\n') |
| else: |
| p.output_code(i, extracted, p.fixedbits, p.fixedmask) |
| #end IncMultiPattern |
| |
| |
| class Tree: |
| """Class representing a node in a decode tree""" |
| |
| def __init__(self, fm, tm): |
| self.fixedmask = fm |
| self.thismask = tm |
| self.subs = [] |
| self.base = None |
| |
| def str1(self, i): |
| ind = str_indent(i) |
| r = ind + whex(self.fixedmask) |
| if self.format: |
| r += ' ' + self.format.name |
| r += ' [\n' |
| for (b, s) in self.subs: |
| r += ind + f' {whex(b)}:\n' |
| r += s.str1(i + 4) + '\n' |
| r += ind + ']' |
| return r |
| |
| def __str__(self): |
| return self.str1(0) |
| |
| def output_code(self, i, extracted, outerbits, outermask): |
| ind = str_indent(i) |
| |
| # If we identified all nodes below have the same format, |
| # extract the fields now. |
| if not extracted and self.base: |
| output(ind, self.base.extract_name(), |
| '(ctx, &u.f_', self.base.base.name, ', insn);\n') |
| extracted = True |
| |
| # Attempt to aid the compiler in producing compact switch statements. |
| # If the bits in the mask are contiguous, extract them. |
| sh = is_contiguous(self.thismask) |
| if sh > 0: |
| # Propagate SH down into the local functions. |
| def str_switch(b, sh=sh): |
| return f'(insn >> {sh}) & {b >> sh:#x}' |
| |
| def str_case(b, sh=sh): |
| return hex(b >> sh) |
| else: |
| def str_switch(b): |
| return f'insn & {whexC(b)}' |
| |
| def str_case(b): |
| return whexC(b) |
| |
| output(ind, 'switch (', str_switch(self.thismask), ') {\n') |
| for b, s in sorted(self.subs): |
| assert (self.thismask & ~s.fixedmask) == 0 |
| innermask = outermask | self.thismask |
| innerbits = outerbits | b |
| output(ind, 'case ', str_case(b), ':\n') |
| output(ind, ' /* ', |
| str_match_bits(innerbits, innermask), ' */\n') |
| s.output_code(i + 4, extracted, innerbits, innermask) |
| output(ind, ' break;\n') |
| output(ind, '}\n') |
| # end Tree |
| |
| |
| class ExcMultiPattern(MultiPattern): |
| """Class representing a non-overlapping set of instruction patterns""" |
| |
| def output_code(self, i, extracted, outerbits, outermask): |
| # Defer everything to our decomposed Tree node |
| self.tree.output_code(i, extracted, outerbits, outermask) |
| |
| @staticmethod |
| def __build_tree(pats, outerbits, outermask): |
| # Find the intersection of all remaining fixedmask. |
| innermask = ~outermask & insnmask |
| for i in pats: |
| innermask &= i.fixedmask |
| |
| if innermask == 0: |
| # Edge condition: One pattern covers the entire insnmask |
| if len(pats) == 1: |
| t = Tree(outermask, innermask) |
| t.subs.append((0, pats[0])) |
| return t |
| |
| text = 'overlapping patterns:' |
| for p in pats: |
| text += '\n' + p.file + ':' + str(p.lineno) + ': ' + str(p) |
| error_with_file(pats[0].file, pats[0].lineno, text) |
| |
| fullmask = outermask | innermask |
| |
| # Sort each element of pats into the bin selected by the mask. |
| bins = {} |
| for i in pats: |
| fb = i.fixedbits & innermask |
| if fb in bins: |
| bins[fb].append(i) |
| else: |
| bins[fb] = [i] |
| |
| # We must recurse if any bin has more than one element or if |
| # the single element in the bin has not been fully matched. |
| t = Tree(fullmask, innermask) |
| |
| for b, l in bins.items(): |
| s = l[0] |
| if len(l) > 1 or s.fixedmask & ~fullmask != 0: |
| s = ExcMultiPattern.__build_tree(l, b | outerbits, fullmask) |
| t.subs.append((b, s)) |
| |
| return t |
| |
| def build_tree(self): |
| super().prop_format() |
| self.tree = self.__build_tree(self.pats, self.fixedbits, |
| self.fixedmask) |
| |
| @staticmethod |
| def __prop_format(tree): |
| """Propagate Format objects into the decode tree""" |
| |
| # Depth first search. |
| for (b, s) in tree.subs: |
| if isinstance(s, Tree): |
| ExcMultiPattern.__prop_format(s) |
| |
| # If all entries in SUBS have the same format, then |
| # propagate that into the tree. |
| f = None |
| for (b, s) in tree.subs: |
| if f is None: |
| f = s.base |
| if f is None: |
| return |
| if f is not s.base: |
| return |
| tree.base = f |
| |
| def prop_format(self): |
| super().prop_format() |
| self.__prop_format(self.tree) |
| |
| # end ExcMultiPattern |
| |
| |
| def parse_field(lineno, name, toks): |
| """Parse one instruction field from TOKS at LINENO""" |
| global fields |
| global insnwidth |
| |
| # A "simple" field will have only one entry; |
| # a "multifield" will have several. |
| subs = [] |
| width = 0 |
| func = None |
| for t in toks: |
| if re.match('^!function=', t): |
| if func: |
| error(lineno, 'duplicate function') |
| func = t.split('=') |
| func = func[1] |
| continue |
| |
| if re.fullmatch('[0-9]+:s[0-9]+', t): |
| # Signed field extract |
| subtoks = t.split(':s') |
| sign = True |
| elif re.fullmatch('[0-9]+:[0-9]+', t): |
| # Unsigned field extract |
| subtoks = t.split(':') |
| sign = False |
| else: |
| error(lineno, f'invalid field token "{t}"') |
| po = int(subtoks[0]) |
| le = int(subtoks[1]) |
| if po + le > insnwidth: |
| error(lineno, f'field {t} too large') |
| f = Field(sign, po, le) |
| subs.append(f) |
| width += le |
| |
| if width > insnwidth: |
| error(lineno, 'field too large') |
| if len(subs) == 0: |
| if func: |
| f = ParameterField(func) |
| else: |
| error(lineno, 'field with no value') |
| else: |
| if len(subs) == 1: |
| f = subs[0] |
| else: |
| mask = 0 |
| for s in subs: |
| if mask & s.mask: |
| error(lineno, 'field components overlap') |
| mask |= s.mask |
| f = MultiField(subs, mask) |
| if func: |
| f = FunctionField(func, f) |
| |
| if name in fields: |
| error(lineno, 'duplicate field', name) |
| fields[name] = f |
| # end parse_field |
| |
| |
| def parse_arguments(lineno, name, toks): |
| """Parse one argument set from TOKS at LINENO""" |
| global arguments |
| global re_C_ident |
| global anyextern |
| |
| flds = [] |
| types = [] |
| extern = False |
| for n in toks: |
| if re.fullmatch('!extern', n): |
| extern = True |
| anyextern = True |
| continue |
| if re.fullmatch(re_C_ident + ':' + re_C_ident, n): |
| (n, t) = n.split(':') |
| elif re.fullmatch(re_C_ident, n): |
| t = 'int' |
| else: |
| error(lineno, f'invalid argument set token "{n}"') |
| if n in flds: |
| error(lineno, f'duplicate argument "{n}"') |
| flds.append(n) |
| types.append(t) |
| |
| if name in arguments: |
| error(lineno, 'duplicate argument set', name) |
| arguments[name] = Arguments(name, flds, types, extern) |
| # end parse_arguments |
| |
| |
| def lookup_field(lineno, name): |
| global fields |
| if name in fields: |
| return fields[name] |
| error(lineno, 'undefined field', name) |
| |
| |
| def add_field(lineno, flds, new_name, f): |
| if new_name in flds: |
| error(lineno, 'duplicate field', new_name) |
| flds[new_name] = f |
| return flds |
| |
| |
| def add_field_byname(lineno, flds, new_name, old_name): |
| return add_field(lineno, flds, new_name, lookup_field(lineno, old_name)) |
| |
| |
| def infer_argument_set(flds): |
| global arguments |
| global decode_function |
| |
| for arg in arguments.values(): |
| if eq_fields_for_args(flds, arg): |
| return arg |
| |
| name = decode_function + str(len(arguments)) |
| arg = Arguments(name, flds.keys(), ['int'] * len(flds), False) |
| arguments[name] = arg |
| return arg |
| |
| |
| def infer_format(arg, fieldmask, flds, width): |
| global arguments |
| global formats |
| global decode_function |
| |
| const_flds = {} |
| var_flds = {} |
| for n, c in flds.items(): |
| if c is ConstField: |
| const_flds[n] = c |
| else: |
| var_flds[n] = c |
| |
| # Look for an existing format with the same argument set and fields |
| for fmt in formats.values(): |
| if arg and fmt.base != arg: |
| continue |
| if fieldmask != fmt.fieldmask: |
| continue |
| if width != fmt.width: |
| continue |
| if not eq_fields_for_fmts(flds, fmt.fields): |
| continue |
| return (fmt, const_flds) |
| |
| name = decode_function + '_Fmt_' + str(len(formats)) |
| if not arg: |
| arg = infer_argument_set(flds) |
| |
| fmt = Format(name, 0, arg, 0, 0, 0, fieldmask, var_flds, width) |
| formats[name] = fmt |
| |
| return (fmt, const_flds) |
| # end infer_format |
| |
| |
| def parse_generic(lineno, parent_pat, name, toks): |
| """Parse one instruction format from TOKS at LINENO""" |
| global fields |
| global arguments |
| global formats |
| global allpatterns |
| global re_arg_ident |
| global re_fld_ident |
| global re_fmt_ident |
| global re_C_ident |
| global insnwidth |
| global insnmask |
| global variablewidth |
| |
| is_format = parent_pat is None |
| |
| fixedmask = 0 |
| fixedbits = 0 |
| undefmask = 0 |
| width = 0 |
| flds = {} |
| arg = None |
| fmt = None |
| for t in toks: |
| # '&Foo' gives a format an explicit argument set. |
| if re.fullmatch(re_arg_ident, t): |
| tt = t[1:] |
| if arg: |
| error(lineno, 'multiple argument sets') |
| if tt in arguments: |
| arg = arguments[tt] |
| else: |
| error(lineno, 'undefined argument set', t) |
| continue |
| |
| # '@Foo' gives a pattern an explicit format. |
| if re.fullmatch(re_fmt_ident, t): |
| tt = t[1:] |
| if fmt: |
| error(lineno, 'multiple formats') |
| if tt in formats: |
| fmt = formats[tt] |
| else: |
| error(lineno, 'undefined format', t) |
| continue |
| |
| # '%Foo' imports a field. |
| if re.fullmatch(re_fld_ident, t): |
| tt = t[1:] |
| flds = add_field_byname(lineno, flds, tt, tt) |
| continue |
| |
| # 'Foo=%Bar' imports a field with a different name. |
| if re.fullmatch(re_C_ident + '=' + re_fld_ident, t): |
| (fname, iname) = t.split('=%') |
| flds = add_field_byname(lineno, flds, fname, iname) |
| continue |
| |
| # 'Foo=number' sets an argument field to a constant value |
| if re.fullmatch(re_C_ident + '=[+-]?[0-9]+', t): |
| (fname, value) = t.split('=') |
| value = int(value) |
| flds = add_field(lineno, flds, fname, ConstField(value)) |
| continue |
| |
| # Pattern of 0s, 1s, dots and dashes indicate required zeros, |
| # required ones, or dont-cares. |
| if re.fullmatch('[01.-]+', t): |
| shift = len(t) |
| fms = t.replace('0', '1') |
| fms = fms.replace('.', '0') |
| fms = fms.replace('-', '0') |
| fbs = t.replace('.', '0') |
| fbs = fbs.replace('-', '0') |
| ubm = t.replace('1', '0') |
| ubm = ubm.replace('.', '0') |
| ubm = ubm.replace('-', '1') |
| fms = int(fms, 2) |
| fbs = int(fbs, 2) |
| ubm = int(ubm, 2) |
| fixedbits = (fixedbits << shift) | fbs |
| fixedmask = (fixedmask << shift) | fms |
| undefmask = (undefmask << shift) | ubm |
| # Otherwise, fieldname:fieldwidth |
| elif re.fullmatch(re_C_ident + ':s?[0-9]+', t): |
| (fname, flen) = t.split(':') |
| sign = False |
| if flen[0] == 's': |
| sign = True |
| flen = flen[1:] |
| shift = int(flen, 10) |
| if shift + width > insnwidth: |
| error(lineno, f'field {fname} exceeds insnwidth') |
| f = Field(sign, insnwidth - width - shift, shift) |
| flds = add_field(lineno, flds, fname, f) |
| fixedbits <<= shift |
| fixedmask <<= shift |
| undefmask <<= shift |
| else: |
| error(lineno, f'invalid token "{t}"') |
| width += shift |
| |
| if variablewidth and width < insnwidth and width % 8 == 0: |
| shift = insnwidth - width |
| fixedbits <<= shift |
| fixedmask <<= shift |
| undefmask <<= shift |
| undefmask |= (1 << shift) - 1 |
| |
| # We should have filled in all of the bits of the instruction. |
| elif not (is_format and width == 0) and width != insnwidth: |
| error(lineno, f'definition has {width} bits') |
| |
| # Do not check for fields overlapping fields; one valid usage |
| # is to be able to duplicate fields via import. |
| fieldmask = 0 |
| for f in flds.values(): |
| fieldmask |= f.mask |
| |
| # Fix up what we've parsed to match either a format or a pattern. |
| if is_format: |
| # Formats cannot reference formats. |
| if fmt: |
| error(lineno, 'format referencing format') |
| # If an argument set is given, then there should be no fields |
| # without a place to store it. |
| if arg: |
| for f in flds.keys(): |
| if f not in arg.fields: |
| error(lineno, f'field {f} not in argument set {arg.name}') |
| else: |
| arg = infer_argument_set(flds) |
| if name in formats: |
| error(lineno, 'duplicate format name', name) |
| fmt = Format(name, lineno, arg, fixedbits, fixedmask, |
| undefmask, fieldmask, flds, width) |
| formats[name] = fmt |
| else: |
| # Patterns can reference a format ... |
| if fmt: |
| # ... but not an argument simultaneously |
| if arg: |
| error(lineno, 'pattern specifies both format and argument set') |
| if fixedmask & fmt.fixedmask: |
| error(lineno, 'pattern fixed bits overlap format fixed bits') |
| if width != fmt.width: |
| error(lineno, 'pattern uses format of different width') |
| fieldmask |= fmt.fieldmask |
| fixedbits |= fmt.fixedbits |
| fixedmask |= fmt.fixedmask |
| undefmask |= fmt.undefmask |
| else: |
| (fmt, flds) = infer_format(arg, fieldmask, flds, width) |
| arg = fmt.base |
| for f in flds.keys(): |
| if f not in arg.fields: |
| error(lineno, f'field {f} not in argument set {arg.name}') |
| if f in fmt.fields.keys(): |
| error(lineno, f'field {f} set by format and pattern') |
| for f in arg.fields: |
| if f not in flds.keys() and f not in fmt.fields.keys(): |
| error(lineno, f'field {f} not initialized') |
| pat = Pattern(name, lineno, fmt, fixedbits, fixedmask, |
| undefmask, fieldmask, flds, width) |
| parent_pat.pats.append(pat) |
| allpatterns.append(pat) |
| |
| # Validate the masks that we have assembled. |
| if fieldmask & fixedmask: |
| error(lineno, 'fieldmask overlaps fixedmask ', |
| f'({whex(fieldmask)} & {whex(fixedmask)})') |
| if fieldmask & undefmask: |
| error(lineno, 'fieldmask overlaps undefmask ', |
| f'({whex(fieldmask)} & {whex(undefmask)})') |
| if fixedmask & undefmask: |
| error(lineno, 'fixedmask overlaps undefmask ', |
| f'({whex(fixedmask)} & {whex(undefmask)})') |
| if not is_format: |
| allbits = fieldmask | fixedmask | undefmask |
| if allbits != insnmask: |
| error(lineno, 'bits left unspecified ', |
| f'({whex(allbits ^ insnmask)})') |
| # end parse_general |
| |
| |
| def parse_file(f, parent_pat): |
| """Parse all of the patterns within a file""" |
| global re_arg_ident |
| global re_fld_ident |
| global re_fmt_ident |
| global re_pat_ident |
| |
| # Read all of the lines of the file. Concatenate lines |
| # ending in backslash; discard empty lines and comments. |
| toks = [] |
| lineno = 0 |
| nesting = 0 |
| nesting_pats = [] |
| |
| for line in f: |
| lineno += 1 |
| |
| # Expand and strip spaces, to find indent. |
| line = line.rstrip() |
| line = line.expandtabs() |
| len1 = len(line) |
| line = line.lstrip() |
| len2 = len(line) |
| |
| # Discard comments |
| end = line.find('#') |
| if end >= 0: |
| line = line[:end] |
| |
| t = line.split() |
| if len(toks) != 0: |
| # Next line after continuation |
| toks.extend(t) |
| else: |
| # Allow completely blank lines. |
| if len1 == 0: |
| continue |
| indent = len1 - len2 |
| # Empty line due to comment. |
| if len(t) == 0: |
| # Indentation must be correct, even for comment lines. |
| if indent != nesting: |
| error(lineno, 'indentation ', indent, ' != ', nesting) |
| continue |
| start_lineno = lineno |
| toks = t |
| |
| # Continuation? |
| if toks[-1] == '\\': |
| toks.pop() |
| continue |
| |
| name = toks[0] |
| del toks[0] |
| |
| # End nesting? |
| if name == '}' or name == ']': |
| if len(toks) != 0: |
| error(start_lineno, 'extra tokens after close brace') |
| |
| # Make sure { } and [ ] nest properly. |
| if (name == '}') != isinstance(parent_pat, IncMultiPattern): |
| error(lineno, 'mismatched close brace') |
| |
| try: |
| parent_pat = nesting_pats.pop() |
| except: |
| error(lineno, 'extra close brace') |
| |
| nesting -= 2 |
| if indent != nesting: |
| error(lineno, 'indentation ', indent, ' != ', nesting) |
| |
| toks = [] |
| continue |
| |
| # Everything else should have current indentation. |
| if indent != nesting: |
| error(start_lineno, 'indentation ', indent, ' != ', nesting) |
| |
| # Start nesting? |
| if name == '{' or name == '[': |
| if len(toks) != 0: |
| error(start_lineno, 'extra tokens after open brace') |
| |
| if name == '{': |
| nested_pat = IncMultiPattern(start_lineno) |
| else: |
| nested_pat = ExcMultiPattern(start_lineno) |
| parent_pat.pats.append(nested_pat) |
| nesting_pats.append(parent_pat) |
| parent_pat = nested_pat |
| |
| nesting += 2 |
| toks = [] |
| continue |
| |
| # Determine the type of object needing to be parsed. |
| if re.fullmatch(re_fld_ident, name): |
| parse_field(start_lineno, name[1:], toks) |
| elif re.fullmatch(re_arg_ident, name): |
| parse_arguments(start_lineno, name[1:], toks) |
| elif re.fullmatch(re_fmt_ident, name): |
| parse_generic(start_lineno, None, name[1:], toks) |
| elif re.fullmatch(re_pat_ident, name): |
| parse_generic(start_lineno, parent_pat, name, toks) |
| else: |
| error(lineno, f'invalid token "{name}"') |
| toks = [] |
| |
| if nesting != 0: |
| error(lineno, 'missing close brace') |
| # end parse_file |
| |
| |
| class SizeTree: |
| """Class representing a node in a size decode tree""" |
| |
| def __init__(self, m, w): |
| self.mask = m |
| self.subs = [] |
| self.base = None |
| self.width = w |
| |
| def str1(self, i): |
| ind = str_indent(i) |
| r = ind + whex(self.mask) + ' [\n' |
| for (b, s) in self.subs: |
| r += ind + f' {whex(b)}:\n' |
| r += s.str1(i + 4) + '\n' |
| r += ind + ']' |
| return r |
| |
| def __str__(self): |
| return self.str1(0) |
| |
| def output_code(self, i, extracted, outerbits, outermask): |
| ind = str_indent(i) |
| |
| # If we need to load more bytes to test, do so now. |
| if extracted < self.width: |
| output(ind, f'insn = {decode_function}_load_bytes', |
| f'(ctx, insn, {extracted // 8}, {self.width // 8});\n') |
| extracted = self.width |
| |
| # Attempt to aid the compiler in producing compact switch statements. |
| # If the bits in the mask are contiguous, extract them. |
| sh = is_contiguous(self.mask) |
| if sh > 0: |
| # Propagate SH down into the local functions. |
| def str_switch(b, sh=sh): |
| return f'(insn >> {sh}) & {b >> sh:#x}' |
| |
| def str_case(b, sh=sh): |
| return hex(b >> sh) |
| else: |
| def str_switch(b): |
| return f'insn & {whexC(b)}' |
| |
| def str_case(b): |
| return whexC(b) |
| |
| output(ind, 'switch (', str_switch(self.mask), ') {\n') |
| for b, s in sorted(self.subs): |
| innermask = outermask | self.mask |
| innerbits = outerbits | b |
| output(ind, 'case ', str_case(b), ':\n') |
| output(ind, ' /* ', |
| str_match_bits(innerbits, innermask), ' */\n') |
| s.output_code(i + 4, extracted, innerbits, innermask) |
| output(ind, '}\n') |
| output(ind, 'return insn;\n') |
| # end SizeTree |
| |
| class SizeLeaf: |
| """Class representing a leaf node in a size decode tree""" |
| |
| def __init__(self, m, w): |
| self.mask = m |
| self.width = w |
| |
| def str1(self, i): |
| return str_indent(i) + whex(self.mask) |
| |
| def __str__(self): |
| return self.str1(0) |
| |
| def output_code(self, i, extracted, outerbits, outermask): |
| global decode_function |
| ind = str_indent(i) |
| |
| # If we need to load more bytes, do so now. |
| if extracted < self.width: |
| output(ind, f'insn = {decode_function}_load_bytes', |
| f'(ctx, insn, {extracted // 8}, {self.width // 8});\n') |
| extracted = self.width |
| output(ind, 'return insn;\n') |
| # end SizeLeaf |
| |
| |
| def build_size_tree(pats, width, outerbits, outermask): |
| global insnwidth |
| |
| # Collect the mask of bits that are fixed in this width |
| innermask = 0xff << (insnwidth - width) |
| innermask &= ~outermask |
| minwidth = None |
| onewidth = True |
| for i in pats: |
| innermask &= i.fixedmask |
| if minwidth is None: |
| minwidth = i.width |
| elif minwidth != i.width: |
| onewidth = False; |
| if minwidth < i.width: |
| minwidth = i.width |
| |
| if onewidth: |
| return SizeLeaf(innermask, minwidth) |
| |
| if innermask == 0: |
| if width < minwidth: |
| return build_size_tree(pats, width + 8, outerbits, outermask) |
| |
| pnames = [] |
| for p in pats: |
| pnames.append(p.name + ':' + p.file + ':' + str(p.lineno)) |
| error_with_file(pats[0].file, pats[0].lineno, |
| f'overlapping patterns size {width}:', pnames) |
| |
| bins = {} |
| for i in pats: |
| fb = i.fixedbits & innermask |
| if fb in bins: |
| bins[fb].append(i) |
| else: |
| bins[fb] = [i] |
| |
| fullmask = outermask | innermask |
| lens = sorted(bins.keys()) |
| if len(lens) == 1: |
| b = lens[0] |
| return build_size_tree(bins[b], width + 8, b | outerbits, fullmask) |
| |
| r = SizeTree(innermask, width) |
| for b, l in bins.items(): |
| s = build_size_tree(l, width, b | outerbits, fullmask) |
| r.subs.append((b, s)) |
| return r |
| # end build_size_tree |
| |
| |
| def prop_size(tree): |
| """Propagate minimum widths up the decode size tree""" |
| |
| if isinstance(tree, SizeTree): |
| min = None |
| for (b, s) in tree.subs: |
| width = prop_size(s) |
| if min is None or min > width: |
| min = width |
| assert min >= tree.width |
| tree.width = min |
| else: |
| min = tree.width |
| return min |
| # end prop_size |
| |
| |
| def main(): |
| global arguments |
| global formats |
| global allpatterns |
| global translate_scope |
| global translate_prefix |
| global output_fd |
| global output_file |
| global input_file |
| global insnwidth |
| global insntype |
| global insnmask |
| global decode_function |
| global bitop_width |
| global variablewidth |
| global anyextern |
| |
| decode_scope = 'static ' |
| |
| long_opts = ['decode=', 'translate=', 'output=', 'insnwidth=', |
| 'static-decode=', 'varinsnwidth='] |
| try: |
| (opts, args) = getopt.gnu_getopt(sys.argv[1:], 'o:vw:', long_opts) |
| except getopt.GetoptError as err: |
| error(0, err) |
| for o, a in opts: |
| if o in ('-o', '--output'): |
| output_file = a |
| elif o == '--decode': |
| decode_function = a |
| decode_scope = '' |
| elif o == '--static-decode': |
| decode_function = a |
| elif o == '--translate': |
| translate_prefix = a |
| translate_scope = '' |
| elif o in ('-w', '--insnwidth', '--varinsnwidth'): |
| if o == '--varinsnwidth': |
| variablewidth = True |
| insnwidth = int(a) |
| if insnwidth == 16: |
| insntype = 'uint16_t' |
| insnmask = 0xffff |
| elif insnwidth == 64: |
| insntype = 'uint64_t' |
| insnmask = 0xffffffffffffffff |
| bitop_width = 64 |
| elif insnwidth != 32: |
| error(0, 'cannot handle insns of width', insnwidth) |
| else: |
| assert False, 'unhandled option' |
| |
| if len(args) < 1: |
| error(0, 'missing input file') |
| |
| toppat = ExcMultiPattern(0) |
| |
| for filename in args: |
| input_file = filename |
| f = open(filename, 'rt', encoding='utf-8') |
| parse_file(f, toppat) |
| f.close() |
| |
| # We do not want to compute masks for toppat, because those masks |
| # are used as a starting point for build_tree. For toppat, we must |
| # insist that decode begins from naught. |
| for i in toppat.pats: |
| i.prop_masks() |
| |
| toppat.build_tree() |
| toppat.prop_format() |
| |
| if variablewidth: |
| for i in toppat.pats: |
| i.prop_width() |
| stree = build_size_tree(toppat.pats, 8, 0, 0) |
| prop_size(stree) |
| |
| if output_file: |
| output_fd = open(output_file, 'wt', encoding='utf-8') |
| else: |
| output_fd = io.TextIOWrapper(sys.stdout.buffer, |
| encoding=sys.stdout.encoding, |
| errors="ignore") |
| |
| output_autogen() |
| for n in sorted(arguments.keys()): |
| f = arguments[n] |
| f.output_def() |
| |
| # A single translate function can be invoked for different patterns. |
| # Make sure that the argument sets are the same, and declare the |
| # function only once. |
| # |
| # If we're sharing formats, we're likely also sharing trans_* functions, |
| # but we can't tell which ones. Prevent issues from the compiler by |
| # suppressing redundant declaration warnings. |
| if anyextern: |
| output("#pragma GCC diagnostic push\n", |
| "#pragma GCC diagnostic ignored \"-Wredundant-decls\"\n", |
| "#ifdef __clang__\n" |
| "# pragma GCC diagnostic ignored \"-Wtypedef-redefinition\"\n", |
| "#endif\n\n") |
| |
| out_pats = {} |
| for i in allpatterns: |
| if i.name in out_pats: |
| p = out_pats[i.name] |
| if i.base.base != p.base.base: |
| error(0, i.name, ' has conflicting argument sets') |
| else: |
| i.output_decl() |
| out_pats[i.name] = i |
| output('\n') |
| |
| if anyextern: |
| output("#pragma GCC diagnostic pop\n\n") |
| |
| for n in sorted(formats.keys()): |
| f = formats[n] |
| f.output_extract() |
| |
| output(decode_scope, 'bool ', decode_function, |
| '(DisasContext *ctx, ', insntype, ' insn)\n{\n') |
| |
| i4 = str_indent(4) |
| |
| if len(allpatterns) != 0: |
| output(i4, 'union {\n') |
| for n in sorted(arguments.keys()): |
| f = arguments[n] |
| output(i4, i4, f.struct_name(), ' f_', f.name, ';\n') |
| output(i4, '} u;\n\n') |
| toppat.output_code(4, False, 0, 0) |
| |
| output(i4, 'return false;\n') |
| output('}\n') |
| |
| if variablewidth: |
| output('\n', decode_scope, insntype, ' ', decode_function, |
| '_load(DisasContext *ctx)\n{\n', |
| ' ', insntype, ' insn = 0;\n\n') |
| stree.output_code(4, 0, 0, 0) |
| output('}\n') |
| |
| if output_file: |
| output_fd.close() |
| # end main |
| |
| |
| if __name__ == '__main__': |
| main() |
