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68 lines
2.1 KiB
Python
68 lines
2.1 KiB
Python
# A subroutine for extracting a function name from a code object
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# (with cache)
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import sys
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from stat import *
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import string
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import os
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import linecache
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# XXX The functions getcodename() and getfuncname() are now obsolete
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# XXX as code and function objects now have a name attribute --
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# XXX co.co_name and f.func_name.
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# Extract the function or class name from a code object.
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# This is a bit of a hack, since a code object doesn't contain
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# the name directly. So what do we do:
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# - get the filename (which *is* in the code object)
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# - look in the code string to find the first SET_LINENO instruction
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# (this must be the first instruction)
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# - get the line from the file
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# - if the line starts with 'class' or 'def' (after possible whitespace),
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# extract the following identifier
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#
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# This breaks apart when the function was read from <stdin>
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# or constructed by exec(), when the file is not accessible,
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# and also when the file has been modified or when a line is
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# continued with a backslash before the function or class name.
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#
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# Because this is a pretty expensive hack, a cache is kept.
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SET_LINENO = 127 # The opcode (see "opcode.h" in the Python source)
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identchars = string.letters + string.digits + '_' # Identifier characters
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_namecache = {} # The cache
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def getcodename(co):
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key = `co` # arbitrary but uniquely identifying string
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if _namecache.has_key(key): return _namecache[key]
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filename = co.co_filename
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code = co.co_code
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name = ''
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if ord(code[0]) == SET_LINENO:
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lineno = ord(code[1]) | ord(code[2]) << 8
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line = linecache.getline(filename, lineno)
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words = string.split(line)
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if len(words) >= 2 and words[0] in ('def', 'class'):
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name = words[1]
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for i in range(len(name)):
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if name[i] not in identchars:
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name = name[:i]
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break
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_namecache[key] = name
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return name
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# Use the above routine to find a function's name.
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def getfuncname(func):
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return getcodename(func.func_code)
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# A part of the above code to extract just the line number from a code object.
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def getlineno(co):
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code = co.co_code
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if ord(code[0]) == SET_LINENO:
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return ord(code[1]) | ord(code[2]) << 8
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else:
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return -1
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