Mercurial > cpython-lru_cache-weakref
annotate Lib/lib-old/codehack.py @ 723:e7571a18bdef legacy-trunk
Add a function to return just the line number of a code object.
| author | Guido van Rossum <guido@python.org> |
|---|---|
| date | Fri, 27 Mar 1992 15:13:08 +0000 |
| parents | a0d4c5ef1d5d |
| children | 1940892d2fe3 |
| rev | line source |
|---|---|
| 622 | 1 # A subroutine for extracting a function name from a code object |
| 2 # (with cache) | |
| 3 | |
| 4 import sys | |
| 5 from stat import * | |
| 6 import string | |
| 7 import os | |
| 8 import linecache | |
| 9 | |
| 10 # Extract the function or class name from a code object. | |
| 11 # This is a bit of a hack, since a code object doesn't contain | |
| 12 # the name directly. So what do we do: | |
| 13 # - get the filename (which *is* in the code object) | |
| 14 # - look in the code string to find the first SET_LINENO instruction | |
| 15 # (this must be the first instruction) | |
| 16 # - get the line from the file | |
| 17 # - if the line starts with 'class' or 'def' (after possible whitespace), | |
| 18 # extract the following identifier | |
| 19 # | |
| 20 # This breaks apart when the function was read from <stdin> | |
| 21 # or constructed by exec(), when the file is not accessible, | |
| 22 # and also when the file has been modified or when a line is | |
| 23 # continued with a backslash before the function or class name. | |
| 24 # | |
| 25 # Because this is a pretty expensive hack, a cache is kept. | |
| 26 | |
| 27 SET_LINENO = 127 # The opcode (see "opcode.h" in the Python source) | |
| 28 identchars = string.letters + string.digits + '_' # Identifier characters | |
| 29 | |
| 30 _namecache = {} # The cache | |
| 31 | |
| 32 def getcodename(co): | |
| 33 key = `co` # arbitrary but uniquely identifying string | |
| 34 if _namecache.has_key(key): return _namecache[key] | |
| 35 filename = co.co_filename | |
| 36 code = co.co_code | |
| 37 name = '' | |
| 38 if ord(code[0]) == SET_LINENO: | |
| 39 lineno = ord(code[1]) | ord(code[2]) << 8 | |
| 40 line = linecache.getline(filename, lineno) | |
| 41 words = string.split(line) | |
| 42 if len(words) >= 2 and words[0] in ('def', 'class'): | |
| 43 name = words[1] | |
| 44 for i in range(len(name)): | |
| 45 if name[i] not in identchars: | |
| 46 name = name[:i] | |
| 47 break | |
| 48 _namecache[key] = name | |
| 49 return name | |
| 50 | |
| 51 # Use the above routine to find a function's name. | |
| 52 | |
| 53 def getfuncname(func): | |
| 54 return getcodename(func.func_code) | |
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723
e7571a18bdef
Add a function to return just the line number of a code object.
Guido van Rossum <guido@python.org>
parents:
622
diff
changeset
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55 |
|
e7571a18bdef
Add a function to return just the line number of a code object.
Guido van Rossum <guido@python.org>
parents:
622
diff
changeset
|
56 # A part of the above code to extract just the line number from a code object. |
|
e7571a18bdef
Add a function to return just the line number of a code object.
Guido van Rossum <guido@python.org>
parents:
622
diff
changeset
|
57 |
|
e7571a18bdef
Add a function to return just the line number of a code object.
Guido van Rossum <guido@python.org>
parents:
622
diff
changeset
|
58 def getlineno(co): |
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e7571a18bdef
Add a function to return just the line number of a code object.
Guido van Rossum <guido@python.org>
parents:
622
diff
changeset
|
59 code = co.co_code |
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e7571a18bdef
Add a function to return just the line number of a code object.
Guido van Rossum <guido@python.org>
parents:
622
diff
changeset
|
60 if ord(code[0]) == SET_LINENO: |
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e7571a18bdef
Add a function to return just the line number of a code object.
Guido van Rossum <guido@python.org>
parents:
622
diff
changeset
|
61 return ord(code[1]) | ord(code[2]) << 8 |
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e7571a18bdef
Add a function to return just the line number of a code object.
Guido van Rossum <guido@python.org>
parents:
622
diff
changeset
|
62 else: |
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e7571a18bdef
Add a function to return just the line number of a code object.
Guido van Rossum <guido@python.org>
parents:
622
diff
changeset
|
63 return -1 |