elf/tst-glibcelf.py

   1 #!/usr/bin/python3
   2 # Verify scripts/glibcelf.py contents against elf/elf.h.
   3 # Copyright (C) 2022-2023 Free Software Foundation, Inc.
   4 # This file is part of the GNU C Library.
   5 #
   6 # The GNU C Library is free software; you can redistribute it and/or
   7 # modify it under the terms of the GNU Lesser General Public
   8 # License as published by the Free Software Foundation; either
   9 # version 2.1 of the License, or (at your option) any later version.
  10 #
  11 # The GNU C Library is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 # Lesser General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU Lesser General Public
  17 # License along with the GNU C Library; if not, see
  18 # <https://www.gnu.org/licenses/>.
  19
  20 import argparse
  21 import sys
  22
  23 import glibcelf
  24 import glibcextract
  25
  26 errors_encountered = 0
  27
  28 def error(message):
  29     global errors_encountered
  30     sys.stdout.write('error: {}\n'.format(message))
  31     errors_encountered += 1
  32
  33 # The enum constants in glibcelf are expected to have exactly these
  34 # prefixes.
  35 expected_constant_prefixes = tuple(
  36     'ELFCLASS ELFDATA EM_ ET_ DT_ PF_ PT_ SHF_ SHN_ SHT_ STB_ STT_'.split())
  37
  38 def find_constant_prefix(name):
  39     """Returns a matching prefix from expected_constant_prefixes or None."""
  40     for prefix in expected_constant_prefixes:
  41         if name.startswith(prefix):
  42             return prefix
  43     return None
  44
  45 def find_enum_types():
  46     """A generator for OpenIntEnum and IntFlag classes in glibcelf."""
  47     classes = set((glibcelf._TypedConstant, glibcelf._IntConstant,
  48                    glibcelf._FlagConstant))
  49     for obj in vars(glibcelf).values():
  50         if isinstance(obj, type) and obj not in classes \
  51            and obj.__bases__[0] in classes:
  52             yield obj
  53
  54 def check_basic():
  55     """Check basic functionality of the constant classes."""
  56
  57     if glibcelf.Pt.PT_NULL is not glibcelf.Pt(0):
  58         error('Pt(0) not interned')
  59     if glibcelf.Pt(17609) is glibcelf.Pt(17609):
  60         error('Pt(17609) unexpectedly interned')
  61     if glibcelf.Pt(17609) == glibcelf.Pt(17609):
  62         pass
  63     else:
  64         error('Pt(17609) equality')
  65     if glibcelf.Pt(17610) == glibcelf.Pt(17609):
  66         error('Pt(17610) equality')
  67
  68     if str(glibcelf.Pt.PT_NULL) != 'PT_NULL':
  69         error('str(PT_NULL)')
  70     if str(glibcelf.Pt(17609)) != '17609':
  71         error('str(Pt(17609))')
  72
  73     if repr(glibcelf.Pt.PT_NULL) != 'PT_NULL':
  74         error('repr(PT_NULL)')
  75     if repr(glibcelf.Pt(17609)) != 'Pt(17609)':
  76         error('repr(Pt(17609))')
  77
  78     if glibcelf.Pt('PT_AARCH64_MEMTAG_MTE') \
  79        is not glibcelf.Pt.PT_AARCH64_MEMTAG_MTE:
  80         error('PT_AARCH64_MEMTAG_MTE identity')
  81     if glibcelf.Pt(0x70000002) is glibcelf.Pt.PT_AARCH64_MEMTAG_MTE:
  82         error('Pt(0x70000002) identity')
  83     if glibcelf.PtAARCH64(0x70000002) is not glibcelf.Pt.PT_AARCH64_MEMTAG_MTE:
  84         error('PtAARCH64(0x70000002) identity')
  85     if glibcelf.Pt.PT_AARCH64_MEMTAG_MTE.short_name != 'AARCH64_MEMTAG_MTE':
  86         error('PT_AARCH64_MEMTAG_MTE short name')
  87
  88     # Special cases for int-like Shn.
  89     if glibcelf.Shn(32) == glibcelf.Shn.SHN_XINDEX:
  90         error('Shn(32)')
  91     if glibcelf.Shn(32) + 0 != 32:
  92         error('Shn(32) + 0')
  93     if 32 in glibcelf.Shn:
  94         error('32 in Shn')
  95     if 0 not in glibcelf.Shn:
  96         error('0 not in Shn')
  97
  98 def check_duplicates():
  99     """Verifies that enum types do not have duplicate values.
 100
 101     Different types must have different member names, too.
 102
 103     """
 104     global_seen = {}
 105     for typ in find_enum_types():
 106         seen = {}
 107         for (name, e) in typ.by_name.items():
 108             if e.value in seen:
 109                 other = seen[e.value]
 110                 # Value conflicts only count if they are between
 111                 # the same base type.
 112                 if e.__class__ is typ and other.__class__ is typ:
 113                     error('{} has {}={} and {}={}'.format(
 114                         typ, other, e.value, name, e.value))
 115             else:
 116                 seen[e.value] = name
 117                 if name in global_seen:
 118                     error('{} used in {} and {}'.format(
 119                         name, global_seen[name], typ))
 120                 else:
 121                     global_seen[name] = typ
 122
 123 def check_constant_prefixes():
 124     """Check that the constant prefixes match expected_constant_prefixes."""
 125     seen = set()
 126     for typ in find_enum_types():
 127         typ_prefix = None
 128         for val in typ.by_name.values():
 129             prefix = find_constant_prefix(val.name)
 130             if prefix is None:
 131                 error('constant {!r} for {} has unknown prefix'.format(
 132                     val, typ))
 133                 break
 134             elif typ_prefix is None:
 135                 typ_prefix = prefix
 136                 seen.add(typ_prefix)
 137             elif prefix != typ_prefix:
 138                 error('prefix {!r} for constant {!r}, expected {!r}'.format(
 139                     prefix, val, typ_prefix))
 140         if typ_prefix is None:
 141             error('empty enum type {}'.format(typ))
 142
 143     for prefix in sorted(set(expected_constant_prefixes) - seen):
 144         error('missing constant prefix {!r}'.format(prefix))
 145     # Reverse difference is already covered inside the loop.
 146
 147 def find_elf_h_constants(cc):
 148     """Returns a dictionary of relevant constants from <elf.h>."""
 149     return glibcextract.compute_macro_consts(
 150         source_text='#include <elf.h>',
 151         cc=cc,
 152         macro_re='|'.join(
 153             prefix + '.*' for prefix in expected_constant_prefixes))
 154
 155 # The first part of the pair is a name of an <elf.h> constant that is
 156 # dropped from glibcelf.  The second part is the constant as it is
 157 # used in <elf.h>.
 158 glibcelf_skipped_aliases = (
 159     ('EM_ARC_A5', 'EM_ARC_COMPACT'),
 160 )
 161
 162 # Constants that provide little value and are not included in
 163 # glibcelf: *LO*/*HI* range constants, *NUM constants counting the
 164 # number of constants.  Also includes the alias names from
 165 # glibcelf_skipped_aliases.
 166 glibcelf_skipped_constants = frozenset(
 167     [e[0] for e in glibcelf_skipped_aliases]) | frozenset("""
 168 DT_AARCH64_NUM
 169 DT_ADDRNUM
 170 DT_ADDRRNGHI
 171 DT_ADDRRNGLO
 172 DT_ALPHA_NUM
 173 DT_ENCODING
 174 DT_EXTRANUM
 175 DT_HIOS
 176 DT_HIPROC
 177 DT_IA_64_NUM
 178 DT_LOOS
 179 DT_LOPROC
 180 DT_MIPS_NUM
 181 DT_NUM
 182 DT_PPC64_NUM
 183 DT_PPC_NUM
 184 DT_PROCNUM
 185 DT_SPARC_NUM
 186 DT_VALNUM
 187 DT_VALRNGHI
 188 DT_VALRNGLO
 189 DT_VERSIONTAGNUM
 190 ELFCLASSNUM
 191 ELFDATANUM
 192 EM_NUM
 193 ET_HIOS
 194 ET_HIPROC
 195 ET_LOOS
 196 ET_LOPROC
 197 ET_NUM
 198 PF_MASKOS
 199 PF_MASKPROC
 200 PT_HIOS
 201 PT_HIPROC
 202 PT_HISUNW
 203 PT_LOOS
 204 PT_LOPROC
 205 PT_LOSUNW
 206 PT_NUM
 207 SHF_MASKOS
 208 SHF_MASKPROC
 209 SHN_HIOS
 210 SHN_HIPROC
 211 SHN_HIRESERVE
 212 SHN_LOOS
 213 SHN_LOPROC
 214 SHN_LORESERVE
 215 SHT_HIOS
 216 SHT_HIPROC
 217 SHT_HIPROC
 218 SHT_HISUNW
 219 SHT_HIUSER
 220 SHT_LOOS
 221 SHT_LOPROC
 222 SHT_LOSUNW
 223 SHT_LOUSER
 224 SHT_NUM
 225 STB_HIOS
 226 STB_HIPROC
 227 STB_LOOS
 228 STB_LOPROC
 229 STB_NUM
 230 STT_HIOS
 231 STT_HIPROC
 232 STT_LOOS
 233 STT_LOPROC
 234 STT_NUM
 235 """.strip().split())
 236
 237 def check_constant_values(cc):
 238     """Checks the values of <elf.h> constants against glibcelf."""
 239
 240     glibcelf_constants = {
 241         e.name: e for typ in find_enum_types() for e in typ.by_name.values()}
 242     elf_h_constants = find_elf_h_constants(cc=cc)
 243
 244     missing_in_glibcelf = (set(elf_h_constants) - set(glibcelf_constants)
 245                            - glibcelf_skipped_constants)
 246     for name in sorted(missing_in_glibcelf):
 247         error('constant {} is missing from glibcelf'.format(name))
 248
 249     unexpected_in_glibcelf = \
 250         set(glibcelf_constants) & glibcelf_skipped_constants
 251     for name in sorted(unexpected_in_glibcelf):
 252         error('constant {} is supposed to be filtered from glibcelf'.format(
 253             name))
 254
 255     missing_in_elf_h = set(glibcelf_constants) - set(elf_h_constants)
 256     for name in sorted(missing_in_elf_h):
 257         error('constant {} is missing from <elf.h>'.format(name))
 258
 259     expected_in_elf_h = glibcelf_skipped_constants - set(elf_h_constants)
 260     for name in expected_in_elf_h:
 261         error('filtered constant {} is missing from <elf.h>'.format(name))
 262
 263     for alias_name, name_in_glibcelf in glibcelf_skipped_aliases:
 264         if name_in_glibcelf not in glibcelf_constants:
 265             error('alias value {} for {} not in glibcelf'.format(
 266                 name_in_glibcelf, alias_name))
 267         elif (int(elf_h_constants[alias_name])
 268               != glibcelf_constants[name_in_glibcelf].value):
 269             error('<elf.h> has {}={}, glibcelf has {}={}'.format(
 270                 alias_name, elf_h_constants[alias_name],
 271                 name_in_glibcelf, glibcelf_constants[name_in_glibcelf]))
 272
 273     # Check for value mismatches:
 274     for name in sorted(set(glibcelf_constants) & set(elf_h_constants)):
 275         glibcelf_value = glibcelf_constants[name].value
 276         elf_h_value = int(elf_h_constants[name])
 277         # On 32-bit architectures <elf.h> has some constants that are
 278         # parsed as signed, while they are unsigned in glibcelf.  So
 279         # far, this only affects some flag constants, so special-case
 280         # them here.
 281         if (glibcelf_value != elf_h_value
 282             and not (isinstance(glibcelf_constants[name],
 283                                 glibcelf._FlagConstant)
 284                      and glibcelf_value == 1 << 31
 285                      and elf_h_value == -(1 << 31))):
 286             error('{}: glibcelf has {!r}, <elf.h> has {!r}'.format(
 287                 name, glibcelf_value, elf_h_value))
 288
 289 def check_hashes():
 290     for name, expected_elf, expected_gnu in (
 291             ('', 0, 0x1505),
 292             ('PPPPPPPPPPPP', 0, 0x9f105c45),
 293             ('GLIBC_2.0', 0xd696910, 0xf66c3dd5),
 294             ('GLIBC_2.34', 0x69691b4, 0xc3f3f90c),
 295             ('GLIBC_PRIVATE', 0x963cf85, 0x692a260)):
 296         for convert in (lambda x: x, lambda x: x.encode('UTF-8')):
 297             name = convert(name)
 298             actual_elf = glibcelf.elf_hash(name)
 299             if actual_elf != expected_elf:
 300                 error('elf_hash({!r}): {:x} != 0x{:x}'.format(
 301                     name, actual_elf, expected_elf))
 302             actual_gnu = glibcelf.gnu_hash(name)
 303             if actual_gnu != expected_gnu:
 304                 error('gnu_hash({!r}): {:x} != 0x{:x}'.format(
 305                     name, actual_gnu, expected_gnu))
 306
 307 def main():
 308     """The main entry point."""
 309     parser = argparse.ArgumentParser(
 310         description="Check glibcelf.py and elf.h against each other.")
 311     parser.add_argument('--cc', metavar='CC',
 312                         help='C compiler (including options) to use')
 313     args = parser.parse_args()
 314
 315     check_basic()
 316     check_duplicates()
 317     check_constant_prefixes()
 318     check_constant_values(cc=args.cc)
 319     check_hashes()
 320
 321     if errors_encountered > 0:
 322         print("note: errors encountered:", errors_encountered)
 323         sys.exit(1)
 324
 325 if __name__ == '__main__':
 326     main()