new file mode 100755
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+#!/usr/bin/python3
+# Copyright (C) 2018 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C 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.
+#
+# The GNU C 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 the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+''' Generate a ChangeLog style output based on the git log.
+
+This script takes two revisions as input and generates a ChangeLog style output
+for all revisions between the two revisions. This output is intended to be an
+approximation and not the exact ChangeLog.
+
+At a high level, the script enumerates all C source files (*.c and *.h) and
+builds a tree of top level objects within macro conditionals. The top level
+objects the script currently attempts to identify are:
+
+ - Include statements
+ - Macro definitions and undefs
+ - Declarations and definitions of variables and functions
+ - Composite types
+
+The script attempts to identify quirks typically used in glibc sources such as
+the symbol hack macro calls that don't use a semicolon and tries to adjust for
+them.
+
+Known Limitations:
+
+ - Does not identify changes in or to comments. Comments are simply stripped
+ out.
+ - Weird nesting of macro conditionals may break things. Attempts have been
+ made to try and maintain state across macro conditional scopes, but
+ there's still scope to fool the script.
+ - Does not identify changes within functions.
+'''
+import subprocess
+import sys
+import os
+import re
+from enum import Enum
+
+# General Utility functions.
+def eprint(*args, **kwargs):
+ ''' Print to stderr.
+ '''
+ print(*args, file=sys.stderr, **kwargs)
+
+
+debug = False
+def debug_print(*args, **kwargs):
+ ''' Convenience function to print diagnostic information in the program.
+ '''
+ if debug:
+ eprint(*args, **kwargs)
+
+
+def usage(name):
+ ''' Print program usage.
+ '''
+ eprint("usage: %s <from-ref> <to-ref>" % name)
+ sys.exit(os.EX_USAGE)
+
+
+def decode(string):
+ ''' Attempt to decode a string.
+
+ Decode a string read from the source file. The multiple attempts are needed
+ due to the presence of the page break characters and some tests in locales.
+ '''
+ codecs = ['utf8', 'latin1', 'cp1252']
+
+ for i in codecs:
+ try:
+ return string.decode(i)
+ except UnicodeDecodeError:
+ pass
+
+ eprint('Failed to decode: %s' % string)
+
+
+#------------------------------------------------------------------------------
+# C Parser.
+#------------------------------------------------------------------------------
+
+
+def new_block(name, type, contents, parent):
+ ''' Create a new code block with the parent as PARENT.
+
+ The code block is a basic structure around which the tree representation of
+ the source code is built. It has the following attributes:
+
+ - type: Any one of the following types in BLOCK_TYPE.
+ - name: A name to refer it by in the ChangeLog
+ - contents: The contents of the block. For a block of types file or
+ macro_cond, this would be a list of blocks that it nests. For other types
+ it is a list with a single string specifying its contents.
+ - parent: This is the parent of the current block, useful in setting up
+ #elif or #else blocks in the tree.
+ - matched: A flag to specify if the block in a tree has found a match in the
+ other tree to which it is being compared.
+ '''
+ block = {}
+ block['matched'] = False
+ block['name'] = name
+ block['type'] = type
+ block['contents'] = contents
+ block['parent'] = parent
+ if parent:
+ parent['contents'].append(block)
+
+ return block
+
+
+class block_type(Enum):
+ ''' Type of code block.
+ '''
+ file = 1
+ macro_cond = 2
+ macro_def = 3
+ macro_undef = 4
+ macro_include = 5
+ macro_info = 6
+ decl = 7
+ func = 8
+ composite = 9
+ macrocall = 10
+ fndecl = 11
+ assign = 12
+
+
+# A dictionary describing what each action (add, modify, delete) show up as in
+# the ChangeLog output.
+actions = {0:{'new': 'New', 'mod': 'Modified', 'del': 'Remove'},
+ block_type.file:{'new': 'New file', 'mod': 'Modified file',
+ 'del': 'Remove file'},
+ block_type.macro_cond:{'new': 'New', 'mod': 'Modified',
+ 'del': 'Remove'},
+ block_type.macro_def:{'new': 'New macro', 'mod': 'Modified macro',
+ 'del': 'Remove macro'},
+ block_type.macro_undef:{'new': 'Undefine', 'mod': 'Modified',
+ 'del': 'Remove'},
+ block_type.macro_include:{'new': 'Include file', 'mod': 'Modified',
+ 'del': 'Remove include'},
+ block_type.macro_info:{'new': 'New preprocessor message',
+ 'mod': 'Modified', 'del': 'Remove'},
+ block_type.decl:{'new': 'New', 'mod': 'Modified', 'del': 'Remove'},
+ block_type.func:{'new': 'New function', 'mod': 'Modified function',
+ 'del': 'Remove function'},
+ block_type.composite:{'new': 'New', 'mod': 'Modified',
+ 'del': 'Remove'},
+ block_type.macrocall:{'new': 'New', 'mod': 'Modified',
+ 'del': 'Remove'},
+ block_type.fndecl:{'new': 'New function', 'mod': 'Modified',
+ 'del': 'Remove'},
+ block_type.assign:{'new': 'New', 'mod': 'Modified', 'del': 'Remove'}}
+
+# Regular expressions.
+
+# The __attribute__ are written in a bunch of different ways in glibc.
+ATTRIBUTE = \
+ r'((_*(attribute|ATTRIBUTE)_*(\s*\(\([^)]+\)\)|\w+))|weak_function)';
+
+# Function regex
+FUNC_RE = re.compile(ATTRIBUTE + r'*\s*(\w+)\s*\([^(][^{]+\)\s*{')
+
+# The macrocall_re peeks into the next line to ensure that it doesn't eat up
+# a FUNC by accident. The func_re regex is also quite crude and only
+# intends to ensure that the function name gets picked up correctly.
+MACROCALL_RE = re.compile(r'(\w+)\s*\((?!void).(\s*,\s*[\w\.]+)*\)$')
+
+# Composite types such as structs and unions.
+COMPOSITE_RE = re.compile(r'(struct|union|enum)\s*(\w*)\s*{')
+
+# Static assignments.
+ASSIGN_RE = re.compile(r'(\w+)\s*(\[[^\]]*\])*\s*([^\s]*attribute[\s\w()]+)?\s*=')
+
+# Function Declarations.
+FNDECL_RE = re.compile(r'(\w+)\s*\([^;]+\)\s*' + ATTRIBUTE + '*;')
+
+# Function pointer typedefs.
+TYPEDEF_FN_RE = re.compile(r'\(\*(\w+)\)\s*\([^)]+\);')
+
+# Simple decls.
+DECL_RE = re.compile(r'(\w+)(\[\w+\])?\s*' + ATTRIBUTE + '?;')
+
+
+def remove_comments(op):
+ ''' Remove comments.
+
+ Return OP by removing all comments from it.
+ '''
+ debug_print('REMOVE COMMENTS')
+
+ sep='\n'
+ opstr = sep.join(op)
+ opstr = re.sub(r'/\*.*?\*/', r'', opstr, flags=re.MULTILINE | re.DOTALL)
+ opstr = re.sub(r'\\\n', r' ', opstr, flags=re.MULTILINE | re.DOTALL)
+ new_op = list(filter(None, opstr.split(sep)))
+
+ return new_op
+
+
+# Parse macros.
+def parse_preprocessor(op, loc, code, start = '', else_start = ''):
+ ''' Parse a preprocessor directive.
+
+ In case a preprocessor condition (i.e. if/elif/else), create a new code
+ block to nest code into and in other cases, identify and add entities suchas
+ include files, defines, etc.
+
+ - NAME is the name of the directive
+ - CUR is the string to consume this expression from
+ - OP is the string array for the file
+ - LOC is the first unread location in CUR
+ - CODE is the block to which we add this function
+
+ - Returns: The next location to be read in the array.
+ '''
+ cur = op[loc]
+ loc = loc + 1
+ endblock = False
+
+ debug_print('PARSE_MACRO: %s' % cur)
+
+ # Remove the # and strip spaces again.
+ cur = cur[1:]
+
+ # Include file.
+ if cur.find('include') == 0:
+ m = re.search(r'include\s*["<]?([^">]+)[">]?', cur)
+ new_block(m.group(1), block_type.macro_include, [cur], code)
+
+ # Macro definition.
+ if cur.find('define') == 0:
+ m = re.search(r'define\s+([a-zA-Z0-9_]+)', cur)
+ new_block(m.group(1), block_type.macro_def, [cur], code)
+
+ # Macro undef.
+ if cur.find('undef') == 0:
+ m = re.search(r'undef\s+([a-zA-Z0-9_]+)', cur)
+ new_block(m.group(1), block_type.macro_undef, [cur], code)
+
+ # #error and #warning macros.
+ if cur.find('error') == 0 or cur.find('warning') == 0:
+ m = re.search(r'(error|warning)\s+"?(.*)"?', cur)
+ if m:
+ name = m.group(2)
+ else:
+ name = '<blank>'
+ new_block(name, block_type.macro_info, [cur], code)
+
+ # Start of an #if or #ifdef block.
+ elif cur.find('if') == 0:
+ rem = re.sub(r'ifndef', r'!', cur).strip()
+ rem = re.sub(r'(ifdef|defined|if)', r'', rem).strip()
+ ifdef = new_block(rem, block_type.macro_cond, [], code)
+ loc = c_parse(op, loc, ifdef, start)
+
+ # End the previous #if/#elif and begin a new block.
+ elif cur.find('elif') == 0 and code['parent']:
+ rem = re.sub(r'(elif|defined)', r'', cur).strip()
+ # The #else and #elif blocks should go into the current block's parent.
+ ifdef = new_block(rem, block_type.macro_cond, [], code['parent'])
+ loc = c_parse(op, loc, ifdef, else_start)
+ endblock = True
+
+ # End the previous #if/#elif and begin a new block.
+ elif cur.find('else') == 0 and code['parent']:
+ name = '!(' + code['name'] + ')'
+ ifdef = new_block(name, block_type.macro_cond, [], code['parent'])
+ loc = c_parse(op, loc, ifdef, else_start)
+ endblock = True
+
+ elif cur.find('endif') == 0 and code['parent']:
+ endblock = True
+
+ return (loc, endblock)
+
+
+# Given the start of a scope CUR, lap up all code up to the end of scope
+# indicated by the closing brace.
+def fast_forward_scope(cur, op, loc):
+ ''' Consume lines in a code block.
+
+ Consume all lines of a block of code such as a composite type declaration or
+ a function declaration.
+
+ - CUR is the string to consume this expression from
+ - OP is the string array for the file
+ - LOC is the first unread location in CUR
+
+ - Returns: The next location to be read in the array as well as the updated
+ value of CUR, which will now have the body of the function or composite
+ type.
+ '''
+ nesting = cur.count('{') - cur.count('}')
+ while nesting > 0 and loc < len(op):
+ cur = cur + ' ' + op[loc]
+
+ nesting = nesting + op[loc].count('{')
+ nesting = nesting - op[loc].count('}')
+ loc = loc + 1
+
+ return (cur, loc)
+
+
+# Different types of declarations.
+def parse_decl(name, cur, op, loc, code, blocktype):
+ ''' Parse a top level declaration.
+
+ All types of declarations except function declarations.
+
+ - NAME is the name of the declarated entity
+ - CUR is the string to consume this expression from
+ - OP is the string array for the file
+ - LOC is the first unread location in CUR
+ - CODE is the block to which we add this function
+
+ - Returns: The next location to be read in the array.
+ '''
+ debug_print('FOUND DECL: %s' % name)
+ new_block(name, blocktype, [cur], code)
+
+ return loc
+
+
+# Assignments.
+def parse_assign(name, cur, op, loc, code, blocktype):
+ ''' Parse an assignment statement.
+
+ This includes array assignments.
+
+ - NAME is the name of the assigned entity
+ - CUR is the string to consume this expression from
+ - OP is the string array for the file
+ - LOC is the first unread location in CUR
+ - CODE is the block to which we add this
+
+ - Returns: The next location to be read in the array.
+ '''
+ debug_print('FOUND ASSIGN: %s' % name)
+ # Lap up everything up to semicolon.
+ while ';' not in cur and loc < len(op):
+ cur = op[loc]
+ loc = loc + 1
+
+ new_block(name, blocktype, [cur], code)
+
+ return loc
+
+
+def parse_composite(name, cur, op, loc, code, blocktype):
+ ''' Parse a composite type.
+
+ Match declaration of a composite type such as a sruct or a union..
+
+ - NAME is the name of the composite type
+ - CUR is the string to consume this expression from
+ - OP is the string array for the file
+ - LOC is the first unread location in CUR
+ - CODE is the block to which we add this
+
+ - Returns: The next location to be read in the array.
+ '''
+ if not name:
+ name = '<anonymous>'
+
+ # Lap up all of the struct definition.
+ (cur, loc) = fast_forward_scope(cur, op, loc)
+
+ new_block(name, blocktype, [cur], code)
+
+ return loc
+
+
+def parse_func(name, cur, op, loc, code, blocktype):
+ ''' Parse a function.
+
+ Match a function definition.
+
+ - NAME is the name of the function
+ - CUR is the string to consume this expression from
+ - OP is the string array for the file
+ - LOC is the first unread location in CUR
+ - CODE is the block to which we add this
+
+ - Returns: The next location to be read in the array.
+ '''
+ debug_print('FOUND FUNC: %s' % name)
+
+ # Consume everything up to the ending brace of the function.
+ (cur, loc) = fast_forward_scope(cur, op, loc)
+
+ new_block(name, blocktype, [cur], code)
+
+ return loc
+
+
+def parse_macrocall(name, cur, op, loc, code, blocktype):
+ ''' Parse a macro call.
+
+ Match a symbol hack macro calls that get added without semicolons.
+
+ - NAME is the name of the macro call
+ - CUR is the string array for the file
+ - CUR is the string to consume this expression from
+ - OP is the string array for the file
+ - CODE is the block to which we add this
+
+ - Returns: The next location to be read in the array.
+ '''
+ debug_print('FOUND MACROCALL: %s' % name)
+
+ new_block(name, blocktype, [cur], code)
+
+ return loc
+
+
+# Regular expressions and token consumption functions for expressions we
+# encounter in C.
+c_expr_parsers = [
+ {'regex' : COMPOSITE_RE, 'func' : parse_composite, 'name' : 2,
+ 'type' : block_type.composite},
+ {'regex' : ASSIGN_RE, 'func' : parse_assign, 'name' : 1,
+ 'type' : block_type.assign},
+ {'regex' : TYPEDEF_FN_RE, 'func' : parse_decl, 'name' : 1,
+ 'type' : block_type.decl},
+ {'regex' : FNDECL_RE, 'func' : parse_decl, 'name' : 1,
+ 'type' : block_type.fndecl},
+ {'regex' : FUNC_RE, 'func' : parse_func, 'name' : 5,
+ 'type' : block_type.func},
+ {'regex' : MACROCALL_RE, 'func' : parse_macrocall, 'name' : 1,
+ 'type' : block_type.macrocall},
+ {'regex' : DECL_RE, 'func' : parse_decl, 'name' : 1,
+ 'type' : block_type.decl}]
+
+
+def parse_c_expr(cur, op, loc, code):
+ ''' Parse a C expression.
+
+ CUR is the string to be parsed, which continues to grow until a match is
+ found. OP is the string array and LOC is the first unread location in the
+ string array. CODE is the block in which any identified expressions should
+ be added.
+ '''
+ debug_print('PARSING: %s' % cur)
+
+ for p in c_expr_parsers:
+ found = re.search(p['regex'], cur)
+ if found:
+ return '', p['func'](found.group(p['name']), cur, op, loc, code,
+ p['type'])
+
+ return cur, loc
+
+
+def c_parse(op, loc, code, start = ''):
+ '''
+ Parse the file line by line. The function assumes a mostly GNU coding
+ standard compliant input so it might barf with anything that is eligible for
+ the Obfuscated C code contest.
+
+ The basic idea of the parser is to identify macro conditional scopes and
+ definitions, includes, etc. and then parse the remaining C code in the
+ context of those macro scopes. The parser does not try to understand the
+ semantics of the code or even validate its syntax. It only records high
+ level symbols in the source and makes a tree structure to indicate the
+ declaration/definition of those symbols and their scope in the macro
+ definitions.
+
+ LOC is the first unparsed line.
+ '''
+ cur = start
+ endblock = False
+
+ while loc < len(op):
+ nextline = op[loc]
+
+ # Macros.
+ if nextline[0] == '#':
+ (loc, endblock) = parse_preprocessor(op, loc, code, cur, start)
+ if endblock and not cur:
+ return loc
+ # Rest of C Code.
+ else:
+ cur = cur + ' ' + nextline
+ cur, loc = parse_c_expr(cur, op, loc + 1, code)
+
+ return loc
+
+
+def c_parse_output(op):
+ ''' File parser.
+
+ Parse the input array of lines OP and generate a tree structure to
+ represent the file. This tree structure is then used for comparison between
+ the old and new file.
+ '''
+ tree = new_block('', block_type.file, [], None)
+ op = remove_comments(op)
+ op = [re.sub(r'#\s+', '#', x) for x in op]
+ op = c_parse(op, 0, tree)
+
+ return tree
+
+
+def print_change(tree, action, prologue = ''):
+ ''' Print the nature of the differences found in the tree compared to the
+ other tree. TREE is the tree that changed, action is what the change was
+ (Added, Removed, Modified) and prologue specifies the macro scope the change
+ is in. The function calls itself recursively for all macro condition tree
+ nodes.
+ '''
+
+ if tree['type'] != block_type.macro_cond:
+ print('\t%s(%s): %s.' % (prologue, tree['name'], action))
+ return
+
+ prologue = '%s[%s]' % (prologue, tree['name'])
+ for t in tree['contents']:
+ if t['type'] == block_type.macro_cond:
+ print_change(t, action, prologue)
+ else:
+ print('\t%s(%s): %s.' % (prologue, t['name'], action))
+
+
+def c_compare_trees(left, right, prologue = ''):
+ ''' Compare two trees and print the difference.
+
+ This routine is the entry point to compare two trees and print out their
+ differences. LEFT and RIGHT will always have the same name and type,
+ starting with block_type.file and '' at the top level.
+ '''
+
+ if left['type'] == block_type.macro_cond or left['type'] == block_type.file:
+
+ if left['type'] == block_type.macro_cond:
+ prologue = '%s[%s]' % (prologue, left['name'])
+
+ # Make sure that everything in the left tree exists in the right tree.
+ for cl in left['contents']:
+ found = False
+ for cr in right['contents']:
+ if not cl['matched'] and not cr['matched'] and \
+ cl['name'] == cr['name'] and cl['type'] == cr['type']:
+ cl['matched'] = cr['matched'] = True
+ c_compare_trees(cl, cr, prologue)
+ found = True
+ break
+ if not found:
+ print_change(cl, actions[cl['type']]['del'], prologue)
+
+ # ... and vice versa. This time we only need to look at unmatched
+ # contents.
+ for cr in right['contents']:
+ if not cr['matched']:
+ print_change(cr, actions[cr['type']]['new'], prologue)
+ else:
+ if left['contents'] != right['contents']:
+ print_change(left, actions[left['type']]['mod'], prologue)
+
+
+def c_dump_tree(tree, indent):
+ ''' Print the entire tree.
+ '''
+ if not debug:
+ return
+
+ if tree['type'] == block_type.macro_cond or tree['type'] == block_type.file:
+ print('%sScope: %s' % (' ' * indent, tree['name']))
+ for c in tree['contents']:
+ c_dump_tree(c, indent + 4)
+ print('%sEndScope: %s' % (' ' * indent, tree['name']))
+ else:
+ if tree['type'] == block_type.func:
+ print('%sFUNC: %s' % (' ' * indent, tree['name']))
+ elif tree['type'] == block_type.composite:
+ print('%sCOMPOSITE: %s' % (' ' * indent, tree['name']))
+ elif tree['type'] == block_type.assign:
+ print('%sASSIGN: %s' % (' ' * indent, tree['name']))
+ elif tree['type'] == block_type.fndecl:
+ print('%sFNDECL: %s' % (' ' * indent, tree['name']))
+ elif tree['type'] == block_type.decl:
+ print('%sDECL: %s' % (' ' * indent, tree['name']))
+ elif tree['type'] == block_type.macrocall:
+ print('%sMACROCALL: %s' % (' ' * indent, tree['name']))
+ elif tree['type'] == block_type.macro_def:
+ print('%sDEFINE: %s' % (' ' * indent, tree['name']))
+ elif tree['type'] == block_type.macro_include:
+ print('%sINCLUDE: %s' % (' ' * indent, tree['name']))
+ elif tree['type'] == block_type.macro_undef:
+ print('%sUNDEF: %s' % (' ' * indent, tree['name']))
+ else:
+ print('%sMACRO LEAF: %s' % (' ' * indent, tree['name']))
+
+
+def c_compare(oldfile, newfile):
+ ''' Entry point for the C backend.
+
+ Parse the two files into trees and compare them. Print the result of the
+ comparison in the ChangeLog-like format.
+ '''
+ left = c_parse_output(oldfile)
+ right = c_parse_output(newfile)
+
+ c_compare_trees(left, right)
+
+ debug_print('LEFT TREE')
+ debug_print('-' * 80)
+ c_dump_tree(left, 0)
+ debug_print('RIGHT TREE')
+ debug_print('-' * 80)
+ c_dump_tree(right, 0)
+
+
+#------------------------------------------------------------------------------
+
+
+# Register backends for specific file extensions.
+BACKENDS = \
+ {'.c': {'compare': c_compare},
+ '.h': {'compare': c_compare}}
+
+
+def get_backend(filename):
+ ''' Get an appropriate backend for FILENAME.
+ '''
+ name, ext = os.path.splitext(filename)
+
+ if not ext in BACKENDS.keys():
+ return None
+
+ return BACKENDS[ext]
+
+
+def exec_git_cmd(args):
+ ''' Execute a git command and return its result as a list of strings.
+ '''
+ args.insert(0, 'git')
+ debug_print(args)
+ proc = subprocess.Popen(args, stdout=subprocess.PIPE)
+
+ # Clean up the output by removing trailing spaces, newlines and dropping
+ # blank lines.
+ op = [decode(x[:-1]).strip() for x in proc.stdout]
+ op = [re.sub(r'\s+', ' ', x) for x in op]
+ op = [x for x in op if x]
+ return op
+
+
+def analyze_diff(oldfile, newfile, filename):
+ ''' Parse the output of the old and new files and print the difference.
+
+ For input files OLDFILE and NEWFILE with name FILENAME, generate reduced
+ trees for them and compare them. We limit our comparison to only C source
+ files.
+ '''
+ backend = get_backend(filename)
+
+ if not backend:
+ return
+
+ backend['compare'](exec_git_cmd(['show', oldfile]),
+ exec_git_cmd(['show', newfile]))
+
+
+def list_changes(commit):
+ ''' List changes in a single commit.
+
+ For the input commit id COMMIT, identify the files that have changed and the
+ nature of their changes. Print commit information in the ChangeLog format,
+ calling into helper functions as necessary.
+ '''
+
+ op = exec_git_cmd(['show', '--date=short', '--raw', commit])
+ author = ''
+ date = ''
+ merge = False
+
+ for l in op:
+ if l.find('Author:') == 0:
+ tmp=l[7:].split('<')
+ authorname = tmp[0].strip()
+ authoremail=tmp[1][:-1].strip()
+ elif l.find('Date:') == 0:
+ date=l[5:].strip()
+ elif l.find('Merge:') == 0:
+ merge = True
+
+ # We got Author and Date, so don't bother with the remaining output.
+ if author != '' and date != '':
+ break
+
+ # Find raw commit information for all non-ChangeLog files.
+ op = [x[1:] for x in op if len(x) > 0 and re.match(r'^:[0-9]+', x) \
+ and 'ChangeLog' not in x]
+
+ # It was only the ChangeLog, ignore.
+ if len(op) == 0:
+ return
+
+ print('%s %s <%s>\n' % (date, authorname, authoremail))
+
+ if merge:
+ print('\t MERGE COMMIT: %s\n' % commit)
+ return
+
+ print('\tCOMMIT: %s' % commit)
+
+ # Each of these lines has a space separated format like so:
+ # :<OLD MODE> <NEW MODE> <OLD REF> <NEW REF> <OPERATION> <FILE1> <FILE2>
+ #
+ # where OPERATION can be one of the following:
+ # A: File added
+ # D: File removed
+ # M[0-9]{3}: File modified
+ # R[0-9]{3}: File renamed, with the 3 digit number following it indicating
+ # what percentage of the file is intact.
+ # C[0-9]{3}: File copied. Same semantics as R.
+ # T: The permission bits of the file changed
+ # U: Unmerged. We should not encounter this, so we ignore it/
+ # X, or anything else: Most likely a bug. Report it.
+ #
+ # FILE2 is set only when OPERATION is R or C, to indicate the new file name.
+ #
+ # Also note that merge commits have a different format here, with three
+ # entries each for the modes and refs, but we don't bother with it for now.
+ #
+ # For more details: https://git-scm.com/docs/diff-format
+ for f in op:
+ data = f.split()
+ if data[4] == 'A':
+ print('\t* %s: New file.' % data[5])
+ elif data[4] == 'D':
+ print('\t* %s: Delete file.' % data[5])
+ elif data[4] == 'T':
+ print('\t* %s: Changed file permission bits from %s to %s' % \
+ (data[5], data[0], data[1]))
+ elif data[4][0] == 'M':
+ print('\t* %s: Modified.' % data[5])
+ analyze_diff(data[2], data[3], data[5])
+ elif data[4][0] == 'R' or data[4][0] == 'C':
+ change = int(data[4][1:])
+ print('\t* %s: Move to...' % data[5])
+ print('\t* %s: ... here.' % data[6])
+ if change < 100:
+ analyze_diff(data[2], data[3], data[6])
+ # We should never encounter this, so ignore for now.
+ elif data[4] == 'U':
+ pass
+ else:
+ eprint('%s: Unknown line format %s' % (commit, data[4]))
+ sys.exit(42)
+
+ print('')
+
+
+def list_commits(revs):
+ ''' List commit IDs between the two revs in the REVS list.
+ '''
+ ref = revs[0] + '..' + revs[1]
+ return exec_git_cmd(['log', '--pretty=%H', ref])
+
+
+def main(revs):
+ ''' ChangeLog Generator Entry Point.
+ '''
+ commits = list_commits(revs)
+ for commit in commits:
+ list_changes(commit)
+
+
+def backend_file_test(f):
+ ''' Parser debugger Entry Point.
+ '''
+ backend = get_backend(f)
+
+ if not backend:
+ debug_print('%s: No backend for this file type, cannot debug' % f)
+ return
+
+ with open(f) as srcfile:
+ op = srcfile.readlines()
+ op = [x[:-1] for x in op]
+ tree = backend['parse_output'](op)
+ backend['dump_tree'](tree, 0)
+
+
+# Program Entry point. If -d is specified, the second argument is assumed to be
+# a file and only the backend for the file is run in verbose mode.
+if __name__ == '__main__':
+ if len(sys.argv) != 3:
+ usage(sys.argv[0])
+
+ if sys.argv[1] == '-d':
+ debug = True
+ backend_file_test(sys.argv[2])
+ else:
+ main(sys.argv[1:])