Added more text to the docstring, updated the way the exit status is
percolated out, and some general cleanup. The output is still the
same, except it now prints "Index: <file>" instead of "Processing:
<file>", so that the output can be used as input for patch (but only
the diff-style parts of it).
diff --git a/Tools/scripts/fixdiv.py b/Tools/scripts/fixdiv.py
index 3b0b628..382503a 100755
--- a/Tools/scripts/fixdiv.py
+++ b/Tools/scripts/fixdiv.py
@@ -5,8 +5,19 @@
To use this tool, first run `python -Dwarn 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 are written to stderr, so you must use `2>'
-for the I/O redirect. I don't yet know how to do this on Windows.)
+`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
@@ -14,7 +25,72 @@
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 a
recommendation to stdout in the form of a context diff. If it is not
-successful, it writes recommendations to stdout instead.
+successful, it writes observations to stdout instead.
+
+There are several possible recommendations and observations:
+
+- A / operator was found that can remain unchanged. This is the
+ recommendation when only float and/or complex arguments were seen.
+
+- A / operator was found that should be changed to //. This is the
+ recommendation when only int and/or long arguments were seen.
+
+- 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.
+
+- 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
+ 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?)
+
+- A warning was seen for a line not containing a / operator. This is
+ an anomaly that shouldn't happen; the most likely cause is 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 was found on one 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, it's not clear whether both were executed. In
+ practice, they usually are, so the default action is make the same
+ recommendation for all / operators, based on the above criteria.
+
+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 will have
+ <string> in the filename position. The fixdiv script will attempt
+ and fail to open a file named "<string>", and issue a warning about
+ this failure. You're on your own to deal with this. 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
@@ -27,30 +103,41 @@
try:
opts, args = getopt.getopt(sys.argv[1:], "h")
except getopt.error, msg:
- usage(2, msg)
+ usage(msg)
+ return 2
for o, a in opts:
if o == "-h":
- help()
+ print __doc__
+ return
if not args:
- usage(2, "at least one file argument is required")
+ 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])
- readwarnings(args[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 file in files:
+ x = process(file, warnings[file])
+ exit = exit or x
+ return exit
-def usage(exit, msg=None):
- if msg:
- sys.stderr.write("%s: %s\n" % (sys.argv[0], msg))
+def usage(msg):
+ sys.stderr.write("%s: %s\n" % (sys.argv[0], msg))
sys.stderr.write("Usage: %s warnings\n" % sys.argv[0])
sys.stderr.write("Try `%s -h' for more information.\n" % sys.argv[0])
- sys.exit(exit)
-def help():
- print __doc__
- sys.exit(0)
+PATTERN = ("^(.+?):(\d+): DeprecationWarning: "
+ "classic (int|long|float|complex) division$")
def readwarnings(warningsfile):
- pat = re.compile(
- "^(.+?):(\d+): DeprecationWarning: classic ([a-z]+) division$")
+ prog = re.compile(PATTERN)
try:
f = open(warningsfile)
except IOError, msg:
@@ -61,7 +148,7 @@
line = f.readline()
if not line:
break
- m = pat.match(line)
+ m = prog.match(line)
if not m:
if line.find("division") >= 0:
sys.stderr.write("Warning: ignored input " + line)
@@ -72,36 +159,32 @@
warnings[file] = list = []
list.append((int(lineno), intern(what)))
f.close()
- files = warnings.keys()
- files.sort()
- for file in files:
- process(file, warnings[file])
+ return warnings
def process(file, list):
print "-"*70
- if not list:
- sys.stderr.write("no division warnings for %s\n" % file)
- return
+ assert list # if this fails, readwarnings() is broken
try:
fp = open(file)
except IOError, msg:
sys.stderr.write("can't open: %s\n" % msg)
- return
- print "Processing:", file
+ return 1
+ print "Index:", file
f = FileContext(fp)
list.sort()
index = 0 # list[:index] has been processed, list[index:] is still to do
- orphans = [] # subset of list for which no / operator was found
- unknown = [] # lines with / operators for which no warnings were seen
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])
@@ -109,7 +192,7 @@
if not slashes and not warnings:
pass
elif slashes and not warnings:
- report(slashes, "Unexecuted code")
+ report(slashes, "No conclusive evidence")
elif warnings and not slashes:
reportphantomwarnings(warnings, f)
else:
@@ -222,7 +305,6 @@
startlineno = endlineno
if token in ("/", "/="):
slashes.append((start, line))
- ## if type in (tokenize.NEWLINE, tokenize.NL, tokenize.COMMENT):
if type == tokenize.NEWLINE:
break
return startlineno, endlineno, slashes
@@ -234,4 +316,4 @@
return line
if __name__ == "__main__":
- main()
+ sys.exit(main())