378 lines
14 KiB
Python
378 lines
14 KiB
Python
#! /usr/bin/env python
|
|
|
|
"""fixdiv - tool to fix division operators.
|
|
|
|
To use this tool, first run `python -Qwarnall yourscript.py 2>warnings'.
|
|
This runs the script `yourscript.py' while writing warning messages
|
|
about all uses of the classic division operator to the file
|
|
`warnings'. The warnings look like this:
|
|
|
|
<file>:<line>: DeprecationWarning: classic <type> division
|
|
|
|
The warnings are written to stderr, so you must use `2>' for the I/O
|
|
redirect. I know of no way to redirect stderr on Windows in a DOS
|
|
box, so you will have to modify the script to set sys.stderr to some
|
|
kind of log file if you want to do this on Windows.
|
|
|
|
The warnings are not limited to the script; modules imported by the
|
|
script may also trigger warnings. In fact a useful technique is to
|
|
write a test script specifically intended to exercise all code in a
|
|
particular module or set of modules.
|
|
|
|
Then run `python fixdiv.py warnings'. This first reads the warnings,
|
|
looking for classic division warnings, and sorts them by file name and
|
|
line number. Then, for each file that received at least one warning,
|
|
it parses the file and tries to match the warnings up to the division
|
|
operators found in the source code. If it is successful, it writes
|
|
its findings to stdout, preceded by a line of dashes and a line of the
|
|
form:
|
|
|
|
Index: <file>
|
|
|
|
If the only findings found are suggestions to change a / operator into
|
|
a // operator, the output is acceptable input for the Unix 'patch'
|
|
program.
|
|
|
|
Here are the possible messages on stdout (N stands for a line number):
|
|
|
|
- A plain-diff-style change ('NcN', a line marked by '<', a line
|
|
containing '---', and a line marked by '>'):
|
|
|
|
A / operator was found that should be changed to //. This is the
|
|
recommendation when only int and/or long arguments were seen.
|
|
|
|
- 'True division / operator at line N' and a line marked by '=':
|
|
|
|
A / operator was found that can remain unchanged. This is the
|
|
recommendation when only float and/or complex arguments were seen.
|
|
|
|
- 'Ambiguous / operator (..., ...) at line N', line marked by '?':
|
|
|
|
A / operator was found for which int or long as well as float or
|
|
complex arguments were seen. This is highly unlikely; if it occurs,
|
|
you may have to restructure the code to keep the classic semantics,
|
|
or maybe you don't care about the classic semantics.
|
|
|
|
- 'No conclusive evidence on line N', line marked by '*':
|
|
|
|
A / operator was found for which no warnings were seen. This could
|
|
be code that was never executed, or code that was only executed
|
|
with user-defined objects as arguments. You will have to
|
|
investigate further. Note that // can be overloaded separately from
|
|
/, using __floordiv__. True division can also be separately
|
|
overloaded, using __truediv__. Classic division should be the same
|
|
as either of those. (XXX should I add a warning for division on
|
|
user-defined objects, to disambiguate this case from code that was
|
|
never executed?)
|
|
|
|
- 'Phantom ... warnings for line N', line marked by '*':
|
|
|
|
A warning was seen for a line not containing a / operator. The most
|
|
likely cause is a warning about code executed by 'exec' or eval()
|
|
(see note below), or an indirect invocation of the / operator, for
|
|
example via the div() function in the operator module. It could
|
|
also be caused by a change to the file between the time the test
|
|
script was run to collect warnings and the time fixdiv was run.
|
|
|
|
- 'More than one / operator in line N'; or
|
|
'More than one / operator per statement in lines N-N':
|
|
|
|
The scanner found more than one / operator on a single line, or in a
|
|
statement split across multiple lines. Because the warnings
|
|
framework doesn't (and can't) show the offset within the line, and
|
|
the code generator doesn't always give the correct line number for
|
|
operations in a multi-line statement, we can't be sure whether all
|
|
operators in the statement were executed. To be on the safe side,
|
|
by default a warning is issued about this case. In practice, these
|
|
cases are usually safe, and the -m option suppresses these warning.
|
|
|
|
- 'Can't find the / operator in line N', line marked by '*':
|
|
|
|
This really shouldn't happen. It means that the tokenize module
|
|
reported a '/' operator but the line it returns didn't contain a '/'
|
|
character at the indicated position.
|
|
|
|
- 'Bad warning for line N: XYZ', line marked by '*':
|
|
|
|
This really shouldn't happen. It means that a 'classic XYZ
|
|
division' warning was read with XYZ being something other than
|
|
'int', 'long', 'float', or 'complex'.
|
|
|
|
Notes:
|
|
|
|
- The augmented assignment operator /= is handled the same way as the
|
|
/ operator.
|
|
|
|
- This tool never looks at the // operator; no warnings are ever
|
|
generated for use of this operator.
|
|
|
|
- This tool never looks at the / operator when a future division
|
|
statement is in effect; no warnings are generated in this case, and
|
|
because the tool only looks at files for which at least one classic
|
|
division warning was seen, it will never look at files containing a
|
|
future division statement.
|
|
|
|
- Warnings may be issued for code not read from a file, but executed
|
|
using an exec statement or the eval() function. These may have
|
|
<string> in the filename position, in which case the fixdiv script
|
|
will attempt and fail to open a file named '<string>' and issue a
|
|
warning about this failure; or these may be reported as 'Phantom'
|
|
warnings (see above). You're on your own to deal with these. You
|
|
could make all recommended changes and add a future division
|
|
statement to all affected files, and then re-run the test script; it
|
|
should not issue any warnings. If there are any, and you have a
|
|
hard time tracking down where they are generated, you can use the
|
|
-Werror option to force an error instead of a first warning,
|
|
generating a traceback.
|
|
|
|
- The tool should be run from the same directory as that from which
|
|
the original script was run, otherwise it won't be able to open
|
|
files given by relative pathnames.
|
|
"""
|
|
|
|
import sys
|
|
import getopt
|
|
import re
|
|
import tokenize
|
|
|
|
multi_ok = 0
|
|
|
|
def main():
|
|
try:
|
|
opts, args = getopt.getopt(sys.argv[1:], "hm")
|
|
except getopt.error, msg:
|
|
usage(msg)
|
|
return 2
|
|
for o, a in opts:
|
|
if o == "-h":
|
|
print __doc__
|
|
return
|
|
if o == "-m":
|
|
global multi_ok
|
|
multi_ok = 1
|
|
if not args:
|
|
usage("at least one file argument is required")
|
|
return 2
|
|
if args[1:]:
|
|
sys.stderr.write("%s: extra file arguments ignored\n", sys.argv[0])
|
|
warnings = readwarnings(args[0])
|
|
if warnings is None:
|
|
return 1
|
|
files = warnings.keys()
|
|
if not files:
|
|
print "No classic division warnings read from", args[0]
|
|
return
|
|
files.sort()
|
|
exit = None
|
|
for filename in files:
|
|
x = process(filename, warnings[filename])
|
|
exit = exit or x
|
|
return exit
|
|
|
|
def usage(msg):
|
|
sys.stderr.write("%s: %s\n" % (sys.argv[0], msg))
|
|
sys.stderr.write("Usage: %s [-m] warnings\n" % sys.argv[0])
|
|
sys.stderr.write("Try `%s -h' for more information.\n" % sys.argv[0])
|
|
|
|
PATTERN = ("^(.+?):(\d+): DeprecationWarning: "
|
|
"classic (int|long|float|complex) division$")
|
|
|
|
def readwarnings(warningsfile):
|
|
prog = re.compile(PATTERN)
|
|
try:
|
|
f = open(warningsfile)
|
|
except IOError, msg:
|
|
sys.stderr.write("can't open: %s\n" % msg)
|
|
return
|
|
warnings = {}
|
|
while 1:
|
|
line = f.readline()
|
|
if not line:
|
|
break
|
|
m = prog.match(line)
|
|
if not m:
|
|
if line.find("division") >= 0:
|
|
sys.stderr.write("Warning: ignored input " + line)
|
|
continue
|
|
filename, lineno, what = m.groups()
|
|
list = warnings.get(filename)
|
|
if list is None:
|
|
warnings[filename] = list = []
|
|
list.append((int(lineno), intern(what)))
|
|
f.close()
|
|
return warnings
|
|
|
|
def process(filename, list):
|
|
print "-"*70
|
|
assert list # if this fails, readwarnings() is broken
|
|
try:
|
|
fp = open(filename)
|
|
except IOError, msg:
|
|
sys.stderr.write("can't open: %s\n" % msg)
|
|
return 1
|
|
print "Index:", filename
|
|
f = FileContext(fp)
|
|
list.sort()
|
|
index = 0 # list[:index] has been processed, list[index:] is still to do
|
|
g = tokenize.generate_tokens(f.readline)
|
|
while 1:
|
|
startlineno, endlineno, slashes = lineinfo = scanline(g)
|
|
if startlineno is None:
|
|
break
|
|
assert startlineno <= endlineno is not None
|
|
orphans = []
|
|
while index < len(list) and list[index][0] < startlineno:
|
|
orphans.append(list[index])
|
|
index += 1
|
|
if orphans:
|
|
reportphantomwarnings(orphans, f)
|
|
warnings = []
|
|
while index < len(list) and list[index][0] <= endlineno:
|
|
warnings.append(list[index])
|
|
index += 1
|
|
if not slashes and not warnings:
|
|
pass
|
|
elif slashes and not warnings:
|
|
report(slashes, "No conclusive evidence")
|
|
elif warnings and not slashes:
|
|
reportphantomwarnings(warnings, f)
|
|
else:
|
|
if len(slashes) > 1:
|
|
if not multi_ok:
|
|
rows = []
|
|
lastrow = None
|
|
for (row, col), line in slashes:
|
|
if row == lastrow:
|
|
continue
|
|
rows.append(row)
|
|
lastrow = row
|
|
assert rows
|
|
if len(rows) == 1:
|
|
print "*** More than one / operator in line", rows[0]
|
|
else:
|
|
print "*** More than one / operator per statement",
|
|
print "in lines %d-%d" % (rows[0], rows[-1])
|
|
intlong = []
|
|
floatcomplex = []
|
|
bad = []
|
|
for lineno, what in warnings:
|
|
if what in ("int", "long"):
|
|
intlong.append(what)
|
|
elif what in ("float", "complex"):
|
|
floatcomplex.append(what)
|
|
else:
|
|
bad.append(what)
|
|
lastrow = None
|
|
for (row, col), line in slashes:
|
|
if row == lastrow:
|
|
continue
|
|
lastrow = row
|
|
line = chop(line)
|
|
if line[col:col+1] != "/":
|
|
print "*** Can't find the / operator in line %d:" % row
|
|
print "*", line
|
|
continue
|
|
if bad:
|
|
print "*** Bad warning for line %d:" % row, bad
|
|
print "*", line
|
|
elif intlong and not floatcomplex:
|
|
print "%dc%d" % (row, row)
|
|
print "<", line
|
|
print "---"
|
|
print ">", line[:col] + "/" + line[col:]
|
|
elif floatcomplex and not intlong:
|
|
print "True division / operator at line %d:" % row
|
|
print "=", line
|
|
elif intlong and floatcomplex:
|
|
print "*** Ambiguous / operator (%s, %s) at line %d:" % (
|
|
"|".join(intlong), "|".join(floatcomplex), row)
|
|
print "?", line
|
|
fp.close()
|
|
|
|
def reportphantomwarnings(warnings, f):
|
|
blocks = []
|
|
lastrow = None
|
|
lastblock = None
|
|
for row, what in warnings:
|
|
if row != lastrow:
|
|
lastblock = [row]
|
|
blocks.append(lastblock)
|
|
lastblock.append(what)
|
|
for block in blocks:
|
|
row = block[0]
|
|
whats = "/".join(block[1:])
|
|
print "*** Phantom %s warnings for line %d:" % (whats, row)
|
|
f.report(row, mark="*")
|
|
|
|
def report(slashes, message):
|
|
lastrow = None
|
|
for (row, col), line in slashes:
|
|
if row != lastrow:
|
|
print "*** %s on line %d:" % (message, row)
|
|
print "*", chop(line)
|
|
lastrow = row
|
|
|
|
class FileContext:
|
|
def __init__(self, fp, window=5, lineno=1):
|
|
self.fp = fp
|
|
self.window = 5
|
|
self.lineno = 1
|
|
self.eoflookahead = 0
|
|
self.lookahead = []
|
|
self.buffer = []
|
|
def fill(self):
|
|
while len(self.lookahead) < self.window and not self.eoflookahead:
|
|
line = self.fp.readline()
|
|
if not line:
|
|
self.eoflookahead = 1
|
|
break
|
|
self.lookahead.append(line)
|
|
def readline(self):
|
|
self.fill()
|
|
if not self.lookahead:
|
|
return ""
|
|
line = self.lookahead.pop(0)
|
|
self.buffer.append(line)
|
|
self.lineno += 1
|
|
return line
|
|
def __getitem__(self, index):
|
|
self.fill()
|
|
bufstart = self.lineno - len(self.buffer)
|
|
lookend = self.lineno + len(self.lookahead)
|
|
if bufstart <= index < self.lineno:
|
|
return self.buffer[index - bufstart]
|
|
if self.lineno <= index < lookend:
|
|
return self.lookahead[index - self.lineno]
|
|
raise KeyError
|
|
def report(self, first, last=None, mark="*"):
|
|
if last is None:
|
|
last = first
|
|
for i in range(first, last+1):
|
|
try:
|
|
line = self[first]
|
|
except KeyError:
|
|
line = "<missing line>"
|
|
print mark, chop(line)
|
|
|
|
def scanline(g):
|
|
slashes = []
|
|
startlineno = None
|
|
endlineno = None
|
|
for type, token, start, end, line in g:
|
|
endlineno = end[0]
|
|
if startlineno is None:
|
|
startlineno = endlineno
|
|
if token in ("/", "/="):
|
|
slashes.append((start, line))
|
|
if type == tokenize.NEWLINE:
|
|
break
|
|
return startlineno, endlineno, slashes
|
|
|
|
def chop(line):
|
|
if line.endswith("\n"):
|
|
return line[:-1]
|
|
else:
|
|
return line
|
|
|
|
if __name__ == "__main__":
|
|
sys.exit(main())
|