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author | Guido van Rossum <guido@python.org> | 1992-01-22 22:21:31 (GMT) |
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committer | Guido van Rossum <guido@python.org> | 1992-01-22 22:21:31 (GMT) |
commit | babe2bf8f45090cef6072e6e6bb38b32afa9423e (patch) | |
tree | 5f44100e0da80f8abb18cbc40f7e4c4b06214fb3 /Lib/lib-old/codehack.py | |
parent | 68c172e3f2aa0ad6d22492417eaa2682bc9f9797 (diff) | |
download | cpython-babe2bf8f45090cef6072e6e6bb38b32afa9423e.zip cpython-babe2bf8f45090cef6072e6e6bb38b32afa9423e.tar.gz cpython-babe2bf8f45090cef6072e6e6bb38b32afa9423e.tar.bz2 |
Initial revision
Diffstat (limited to 'Lib/lib-old/codehack.py')
-rw-r--r-- | Lib/lib-old/codehack.py | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/Lib/lib-old/codehack.py b/Lib/lib-old/codehack.py new file mode 100644 index 0000000..8a4f611 --- /dev/null +++ b/Lib/lib-old/codehack.py @@ -0,0 +1,54 @@ +# A subroutine for extracting a function name from a code object +# (with cache) + +import sys +from stat import * +import string +import os +import linecache + +# Extract the function or class name from a code object. +# This is a bit of a hack, since a code object doesn't contain +# the name directly. So what do we do: +# - get the filename (which *is* in the code object) +# - look in the code string to find the first SET_LINENO instruction +# (this must be the first instruction) +# - get the line from the file +# - if the line starts with 'class' or 'def' (after possible whitespace), +# extract the following identifier +# +# This breaks apart when the function was read from <stdin> +# or constructed by exec(), when the file is not accessible, +# and also when the file has been modified or when a line is +# continued with a backslash before the function or class name. +# +# Because this is a pretty expensive hack, a cache is kept. + +SET_LINENO = 127 # The opcode (see "opcode.h" in the Python source) +identchars = string.letters + string.digits + '_' # Identifier characters + +_namecache = {} # The cache + +def getcodename(co): + key = `co` # arbitrary but uniquely identifying string + if _namecache.has_key(key): return _namecache[key] + filename = co.co_filename + code = co.co_code + name = '' + if ord(code[0]) == SET_LINENO: + lineno = ord(code[1]) | ord(code[2]) << 8 + line = linecache.getline(filename, lineno) + words = string.split(line) + if len(words) >= 2 and words[0] in ('def', 'class'): + name = words[1] + for i in range(len(name)): + if name[i] not in identchars: + name = name[:i] + break + _namecache[key] = name + return name + +# Use the above routine to find a function's name. + +def getfuncname(func): + return getcodename(func.func_code) |