Fix typo endianess -> endianness
Rename contrib/struct_endianess.py to contrib/struct_endianness.py, and
fix the typo everywhere. This is in preparation to call the script in
CI on all repositories.
Related: OS#5884
Change-Id: Idc4af9098ba1de26243464c772d6ea8be330646a
diff --git a/contrib/struct_endianness.py b/contrib/struct_endianness.py
new file mode 100755
index 0000000..2601869
--- /dev/null
+++ b/contrib/struct_endianness.py
@@ -0,0 +1,371 @@
+#!/usr/bin/env python3
+
+'''Using mad regexes, automatically make sure that all structs with sub-byte
+integers have matching big-endian definitions. The idea is to save a lot of
+manual effort, and to automatically verify that there are no errors.
+This script most certainly has numerous holes and shortcomings, but actually,
+if you hit problems with it, rather adjust your coding style so that this
+script can deal with it...'''
+
+import re
+import sys
+import codecs
+import os.path
+
+re_struct_start = re.compile(r'^struct\s*[a-zA-Z_][a-zA-Z_0-9]*\s*{\s*$')
+re_struct_end = re.compile(r'^}[^;]*;\s*$')
+
+re_substruct_start = re.compile(r'^\s+struct\s*{\s*$')
+re_substruct_end = re.compile(r'^\s+}\s*([^;]*\s)[a-zA-Z_][a-zA-Z_0-9]*\s*;\s*$')
+re_unnamed_substruct_end = re.compile(r'^\s+}\s*;\s*$')
+
+re_int_def = re.compile(r'(^\s*((const|unsigned|signed|char|int|long|int[0-9]+_t|uint[0-9]_t)\s+)+\s*)([^;]*;)',
+ re.DOTALL | re.MULTILINE)
+re_int_members = re.compile(r'([a-zA-Z_][a-zA-Z_0-9]*|[a-zA-Z_][a-zA-Z_0-9]*\s*:\s*[0-9]+)\s*[,;]\s*', re.DOTALL | re.MULTILINE)
+
+re_little_endian_ifdef = re.compile(r'#\s*(if|elif)\s+OSMO_IS_LITTLE_ENDIAN\s*(==\s*1\s*|)');
+re_big_endian_ifdef = re.compile(r'#\s*(if|elif)\s+OSMO_IS_BIG_ENDIAN\s*');
+re_else = re.compile(r'#\s*else\s*');
+re_endif = re.compile(r'#\s*endif\s*');
+
+re_c_comment = re.compile(r'(/\*[^*]+\*/|//.?$)')
+
+def remove_c_comments(code_str):
+ return ''.join(re_c_comment.split(code_str)[::2])
+
+def section_struct_body(struct_body_lines):
+ '''divide a top-level-struct body into sections of
+ ['arbitrary string', ['body;\n', 'lines;\n'], 'arbitrary string', ...]
+ Aim: handle each sub-struct on its own, and if there already are ifdefs for
+ little and big endian, keep just the little endian bit and derive big
+ endian from it.
+ An arbitrary string is anything other than struct member definitions, like
+ a 'struct {', '} sub_name;', ...
+ "body lines" are lines that define struct members (possibly with comments).
+ Return: list of alternate arbitrary strings and variable definitions.
+ '''
+
+ # these globals are needed so that end_def() can change them from inside
+ # the function. Not very nice style, but easiest implementation.
+ global struct_body_parts
+ global arbitrary_part
+ global def_part
+
+ struct_body_parts = []
+ arbitrary_part = []
+ def_part = []
+
+ def end_def():
+ '''if there is any content, flush out recorded parts (def_part,
+ arbitrary_part) and start a new part. In short, cut a section
+ boundary.'''
+ global struct_body_parts
+ global arbitrary_part
+ global def_part
+
+ if def_part:
+ struct_body_parts.append(arbitrary_part)
+ arbitrary_part = []
+ struct_body_parts.append(def_part)
+ def_part = []
+
+ j = 0
+ while j < len(struct_body_lines):
+ line = struct_body_lines[j]
+
+ if (re_substruct_start.fullmatch(line)
+ or re_substruct_end.fullmatch(line)
+ or re_unnamed_substruct_end.fullmatch(line)):
+ end_def()
+ arbitrary_part.append(line)
+ j += 1
+ continue
+
+ if re_big_endian_ifdef.fullmatch(line):
+ end_def()
+ # discard big endian section
+ j += 1
+ while j < len(struct_body_lines):
+ line = struct_body_lines[j]
+ if re_endif.fullmatch(line):
+ end_def()
+ j += 1
+ break;
+ if re_little_endian_ifdef.fullmatch(line):
+ end_def()
+ # keep that start of little endian section, not j++
+ break;
+ if re_else.fullmatch(line):
+ # there's an '#else' after big-endian. Shim a little-endian header in just for the loop.
+ struct_body_lines[j] = '#if OSMO_IS_LITTLE_ENDIAN\n'
+ break;
+ j += 1
+ continue
+
+ if re_little_endian_ifdef.fullmatch(line):
+ end_def()
+ j += 1
+ while j < len(struct_body_lines):
+ line = struct_body_lines[j]
+ if re_endif.fullmatch(line):
+ end_def()
+ j += 1
+ break;
+ if re_big_endian_ifdef.fullmatch(line):
+ end_def()
+ # keep that start of big endian section, not j++
+ break;
+ if re_else.fullmatch(line):
+ # there's an '#else' after little-endian. Shim a big-endian header in just for the loop.
+ struct_body_lines[j] = '#if OSMO_IS_BIG_ENDIAN\n'
+ break;
+ def_part.append(line)
+ j += 1
+
+ continue
+
+ def_part.append(line)
+ j += 1
+
+ # flush the last section remaining that didn't see an explicit end
+ end_def()
+ # end_def() only flushes arbitrary_part if there was a def_part, so:
+ if arbitrary_part:
+ struct_body_parts.append(arbitrary_part)
+
+ return struct_body_parts
+
+def struct_body_to_big_endian(body_str):
+ '''Input: a multi-line string containing the body of a struct, i.e. without
+ sub-structs and without #if OSMO_IS_BIG_ENDIAN. like
+
+ '\tconst char *foo;\n\tuint8_t moo:3, goo:2;\n\tuint8_t loo:3;\n\tvoid *baz;\n'
+
+ Return None to indicate that there is no little/big endian split
+ required, or return a multi-line string of the big-endian version of this
+ same struct body, where sub-byte ints are reversed at byte boundaries, and
+ all others are copied 1:1. If there are no sub-byte integers, return None,
+ to indicate that there is no little/big endian split required.'''
+
+ # kick comments out of the code analysis. They will end up being stripped
+ # from big-endian only.
+ body_str = remove_c_comments(body_str)
+
+ def_strs = body_str.split(';')
+ def_strs = ('%s;' % def_str for def_str in def_strs if def_str.strip())
+
+ # classify defs as containing sub-byte members or not
+ # defs = [ (true, 'uint8_t ', ('foo:3', 'bar:5')),
+ # (false, 'int baz;'),...]
+ defs = []
+ any_sub_byte_ints = False
+ for one_def in def_strs:
+
+ # does it have sub-string integers?
+ int_def = re_int_def.fullmatch(one_def)
+ if not int_def:
+ # not even a number, same for big and little endian
+ defs.append((False, one_def))
+ continue
+
+ int_type = int_def.group(1)
+ members_str = int_def.groups()[-1]
+ has_sub_byte_ints = False
+
+ members = []
+ for int_member in re_int_members.finditer(members_str):
+ member = int_member.group(1)
+ members.append(member)
+ if ':' in member:
+ has_sub_byte_ints = True
+
+ if not has_sub_byte_ints:
+ defs.append((False, one_def))
+ else:
+ defs.append((True, one_def, int_type, members))
+ any_sub_byte_ints = True
+
+ if not any_sub_byte_ints:
+ return None
+
+ # now the interesting part, go over the defs, and reverse the sub-byte ints
+ # at byte boundaries.
+
+ i = 0
+ got_bits = 0
+ byte_type = None
+ members_within_a_byte = []
+ big_endian_defs = []
+
+ big_defs = []
+ for classified_def in defs:
+ has_sub_byte_ints = classified_def[0]
+
+ # now the big endian part
+ if has_sub_byte_ints:
+ _, one_def, int_type, members = classified_def
+
+ if byte_type and byte_type.strip() != int_type.strip():
+ raise Exception('mismatching type continuation after incomplete byte: %r %r to %r'
+ % (byte_type, members_within_a_byte, int_type))
+ byte_type = int_type
+
+ for member in members:
+ member_name, bits_str = member.split(':')
+ member_name = member_name.strip()
+ bits = int(bits_str)
+ member = '%s:%d' % (member_name, bits)
+ members_within_a_byte.append(member)
+ got_bits += bits
+
+ if got_bits == 8:
+ # reverse these.
+ big_endian_defs.append('%s%s;' % (byte_type, ', '.join(reversed(members_within_a_byte))))
+ members_within_a_byte = []
+ byte_type = None
+ got_bits = 0
+
+ elif got_bits > 8:
+ raise Exception('sub-byte int breaks clean byte bounds: %s -- %d + %d = %d bits'
+ % (member, got_bits - bits, bits, got_bits))
+
+ elif not has_sub_byte_ints:
+ if got_bits:
+ raise Exception('sub-byte members do not add up to clean byte bounds: %r' % members_within_a_byte)
+
+ big_endian_defs.append(classified_def[1])
+
+ # strip empty lines
+ lines = [l for l in (''.join(big_endian_defs).split('\n')) if l.strip()]
+ # clean lines' whitespace errors we might have taken in with the type names
+ for i in range(len(lines)):
+ line = lines[i]
+ while len(line) and line[-1] in ' \t':
+ line = line[:-1]
+ lines[i] = line
+ return '\n'.join(lines)
+
+def handle_struct_body(body_str):
+
+ big_endian_body_str = struct_body_to_big_endian(body_str)
+
+ if big_endian_body_str:
+ new_lines = ['#if OSMO_IS_LITTLE_ENDIAN\n']
+ new_lines.append(body_str)
+ new_lines.append('#elif OSMO_IS_BIG_ENDIAN\n'
+ '/* auto-generated from the little endian part above (libosmocore/contrib/struct_endianness.py) */\n')
+ new_lines.append(big_endian_body_str)
+ new_lines.append('\n#endif\n')
+ return ''.join(new_lines)
+ else:
+ return body_str
+
+def _check_file(f):
+ if not (f.endswith('.h') or f.endswith('.c') or f.endswith('.cpp')):
+ return
+
+ # section the file into
+ # [ ["no struct def"], ["struct {...};"], ["no struct def"], ... ]
+ sections = []
+ in_struct = False
+ buf = []
+ for line in codecs.open(f, "r", "utf-8").readlines():
+
+ if not in_struct and re_struct_start.fullmatch(line):
+ # flush whatever might still be in buf from before
+ sections.append(buf)
+ # start an in_struct section
+ buf = [line]
+ in_struct = True
+ elif in_struct and re_struct_end.fullmatch(line):
+ # add this end to the in_struct section and then start a non-struct section
+ buf.append(line)
+ sections.append(buf)
+ in_struct = False
+ buf = []
+ else:
+ buf.append(line)
+ # flush any leftovers in buf
+ if buf:
+ sections.append(buf)
+
+ # examine each struct, i.e. every second item in 'sections'
+ for i in range(len(sections)):
+ if not (i & 1):
+ continue
+
+ struct = sections[i]
+
+ # If the struct isn't packed, we need not bother.
+ # The practical use of this: in some structs we have booleans in the
+ # form of
+ # integer flag:1;
+ # and these don't add up to bytes, and cause errors. So let's skip all
+ # non-packed structs, then all of those are out of the picture.
+ if not 'packed' in struct[-1]:
+ continue
+
+ try:
+
+ # assume the 'struct foo {' is on the first line, the closing brace
+ # '} __attribute...;' on the last, and the rest are individual
+ # definitions split by ';'.
+ struct_body_lines = struct[1:-1]
+ struct_body_parts = section_struct_body(struct_body_lines)
+
+ new_struct_body_parts = []
+ for j in range(len(struct_body_parts)):
+ part = ''.join(struct_body_parts[j])
+ if not (j & 1):
+ new_struct_body_parts.append(part)
+ else:
+ new_struct_body_parts.append(handle_struct_body(part))
+
+ new_struct = [struct[0], ''.join(new_struct_body_parts), struct[-1]]
+ sections[i] = new_struct
+ except Exception as e:
+ raise Exception('ERROR in struct %r' % struct[0])
+
+ # phew. result.
+ result = ''.join((''.join(s) for s in sections))
+
+ # see if osmocom/core/endian.h is needed and included.
+ if (not f.endswith('endian.h')
+ and 'OSMO_IS_LITTLE_ENDIAN' in result
+ and '#include <osmocom/core/endian.h>' not in result):
+ # add the include after the last 'osmocom/core' include
+ last_include_start = result.rfind('#include <osmocom/core/')
+ if last_include_start < 0:
+ last_include_start = result.rfind('#include <osmocom/')
+ if last_include_start < 0:
+ last_include_start = result.rfind('#include')
+
+ if last_include_start < 0:
+ raise Exception('do not know where to include osmocom/core/endian.h in %r' % f)
+
+ insert_at = result.find('\n', last_include_start)
+
+ result = result[:insert_at] + '\n#include <osmocom/core/endian.h>' + result[insert_at:]
+
+ with codecs.open(f, "w", "utf-8") as fd:
+ fd.write(result)
+
+def check_file(f):
+ try:
+ _check_file(f)
+ except Exception as e:
+ raise Exception('ERROR IN FILE %r' % f)
+
+args = sys.argv[1:]
+if not args:
+ args = ['.']
+
+for f in args:
+ if os.path.isdir(f):
+ for parent_path, subdirs, files in os.walk(f, None, None):
+ for ff in files:
+ check_file(os.path.join(parent_path, ff))
+ else:
+ check_file(f)
+
+# vim: tabstop=4 shiftwidth=4 expandtab