Bugs item #1333982, was opened at 2005-10-21 03:08 Message generated for change (Comment added) made by nnorwitz You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1333982&group_id=5470
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Category: Parser/Compiler Group: AST Status: Open Resolution: None Priority: 9 Submitted By: Armin Rigo (arigo) >Assigned to: Neal Norwitz (nnorwitz) Summary: Bugs of the new AST compiler Initial Comment: The newly merged AST branch is likely to expose a number of small problems before it stabilizes, so here is a tentative bug tracker entry to collect such small problems. ---------------------------------------------------------------------- >Comment By: Neal Norwitz (nnorwitz) Date: 2006-08-03 00:26 Message: Logged In: YES user_id=33168 Fix pending. need tests and code to be thawed. ---------------------------------------------------------------------- Comment By: Neil Schemenauer (nascheme) Date: 2006-07-09 14:23 Message: Logged In: YES user_id=35752 Unary minus bug has been fixed in SVN rev 50495. ---------------------------------------------------------------------- Comment By: Neil Schemenauer (nascheme) Date: 2006-07-09 14:05 Message: Logged In: YES user_id=35752 Regarding the -2147483648 bug: the old compiler tries to fold unary +, - and ~ if the RHS is a constant. I think only the minus case is important since the others are just optimizations, right? Attaching what seems to be a minimum fix. ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2006-07-02 04:29 Message: Logged In: YES user_id=4771 Attached a patch for the LOAD_CONST POP_TOP optimization (modified from Georg Brandl on python-dev). ---------------------------------------------------------------------- Comment By: Michael Hudson (mwh) Date: 2006-04-11 02:41 Message: Logged In: YES user_id=6656 Good morning Armin! I've reported that bug already: http://python.org/sf/1441486 There's a patch which purports to fix it: http://python.org/sf/1446922 but I haven't gotten around to testing it. (this is running the pypy/module/array tests or something, isn't it?) ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2006-04-11 01:45 Message: Logged In: YES user_id=4771 Another one: the literal -2147483648 (i.e. the value of -sys.maxint-1) gives a long in 2.5, but an int in <= 2.4. ---------------------------------------------------------------------- Comment By: Neal Norwitz (nnorwitz) Date: 2006-04-03 00:30 Message: Logged In: YES user_id=33168 The tuple store problem is fixed. The only outstanding item is the LOAD_CONST/POP_TOP. I will fix that soon. ---------------------------------------------------------------------- Comment By: Neal Norwitz (nnorwitz) Date: 2006-02-17 22:56 Message: Logged In: YES user_id=33168 Jeremy, there's no need to read anything before my last comment at 2005-12-17 23:10. The last two by Armin, Michael, then my last comment are the only important ones. Everything that occurred before my 2005-12-17 comment was taken care of AFAIK. ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2006-02-12 13:54 Message: Logged In: YES user_id=4771 Subscripting is generally a bit sloppy: e.g. the AST model has no way to distinguish between a single value and a one-element tuple value! See: >>> d = {} >>> d[1,] = 6 >>> d {1: 6} # ! I suggest we fix the model to turn the 'subs' of the 'Subscript' node from a list of nodes to a single, mandatory 'sub' node. If tupling is necessary, it can be explicitly represented with a 'sub' containing a 'Tuple' node. ---------------------------------------------------------------------- Comment By: Michael Hudson (mwh) Date: 2006-02-09 07:02 Message: Logged In: YES user_id=6656 We found another one. Something is wrong in the compilation of augmented assignment to subscriptions containing tuples; running this code: class C: def __setitem__(self, i, v): print i, v def __getitem__(self, i): print i return 0 c = C() c[4,5] += 1 gives a spurious exception: Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: object does not support item assignment By contrast, "c[(4,5)] += 1" works fine. ---------------------------------------------------------------------- Comment By: Neal Norwitz (nnorwitz) Date: 2005-12-17 23:10 Message: Logged In: YES user_id=33168 EXTENDED_ARG problem was fixed a while ago. The assert/pass problem was fixed with: 41756. That leaves the LOAD_CONST/POP_TOP optimization that was lost and one compiler warning: marshal_write_mod() not being used. ---------------------------------------------------------------------- Comment By: Michael Hudson (mwh) Date: 2005-12-10 16:41 Message: Logged In: YES user_id=6656 You have to include those lines in a source file. It still crashes for me. ---------------------------------------------------------------------- Comment By: Brett Cannon (bcannon) Date: 2005-12-10 15:44 Message: Logged In: YES user_id=357491 I just checked Armin's problem code on rev. 41638 and it worked for me in the interpreter. You still having problems, Armin? ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2005-12-04 02:30 Message: Logged In: YES user_id=4771 At rev 41584, the following code snippet triggers an assert if --with-pydebug is enabled: Python/compile.c:3843: assemble_lnotab: Assertion 'd_lineno >= 0' failed ----------------------- assert 1, ([s for s in x] + [s for s in x]) pass ----------------------- ---------------------------------------------------------------------- Comment By: Neal Norwitz (nnorwitz) Date: 2005-10-23 12:14 Message: Logged In: YES user_id=33168 Checkpoint of outstanding issues. I think all the others mentioned so far have been fixed: * Raymond's warnings in compile.c (unused locals are fixed) * EXTENDED_ARG problem * LOAD_CONST/POP_TOP (note we can fix this in the optimizer generally which would get rid of other useless code too) ---------------------------------------------------------------------- Comment By: Raymond Hettinger (rhettinger) Date: 2005-10-22 21:53 Message: Logged In: YES user_id=80475 FWIW, here are the warnings issued by my compiler: Python-ast.c C:\py25\Python\Python-ast.c(1995) : warning C4101: 'i' : unreferenced local variable C:\py25\Python\Python-ast.c(2070) : warning C4101: 'i' : unreferenced local variable C:\py25\Python\Python-ast.c(2085) : warning C4101: 'i' : unreferenced local variable C:\py25\Python\Python-ast.c(2130) : warning C4101: 'i' : unreferenced local variable C:\py25\Python\Python-ast.c(2151) : warning C4101: 'i' : unreferenced local variable C:\py25\Python\Python-ast.c(2261) : warning C4101: 'i' : unreferenced local variable C:\py25\Python\Python-ast.c(2270) : warning C4101: 'i' : unreferenced local variable compile.c C:\py25\Python\compile.c(3782) : warning C4305: '=' : truncation from 'const int ' to 'char ' C:\py25\Python\compile.c(3802) : warning C4305: '=' : truncation from 'const int ' to 'char ' C:\py25\Python\compile.c(3806) : warning C4305: '=' : truncation from 'const int ' to 'char ' ---------------------------------------------------------------------- Comment By: Neal Norwitz (nnorwitz) Date: 2005-10-22 00:28 Message: Logged In: YES user_id=33168 I assigned to Jeremy and Neil in the hopes they will see this message and know about these problems. ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2005-10-21 05:45 Message: Logged In: YES user_id=4771 The following (similarly strange-looking) code snippets compiled successfully before, now they give SyntaxErrors: -------------------- def f(): class g: exec "hi" x -------------------- def f(x): class g: exec "hi" x -------------------- def f(): class g: from a import * x -------------------- def f(x): class g: from a import * x ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2005-10-21 05:33 Message: Logged In: YES user_id=4771 I would suspect the following one to be due to incorrect handling of EXTENDED_ARG -- it's from a PyPy test about that: longexpr = 'x = x or ' + '-x' * 2500 code = ''' def f(x): %s %s %s %s %s %s %s %s %s %s while x: x -= 1 # EXTENDED_ARG/JUMP_ABSOLUTE here return x ''' % ((longexpr,)*10) exec code f(5) SystemError: unknown opcode dis.dis() shows that the target of both the SETUP_LOOP and the JUMP_IF_FALSE at the start of the loop are wrong. ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2005-10-21 05:15 Message: Logged In: YES user_id=4771 The Python rules about which names get mangled are a bit insane. I share mwh's view that mangling should never have been invented in the first place, but well: >>> def f(): ... __x = 5 ... class X: ... def g(self): ... return __x ... return X ... Fatal Python error: unknown scope for _X__x in X(135832776) in <stdin> ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2005-10-21 05:01 Message: Logged In: YES user_id=4771 For reference, an optimization that got lost: def f(): 'a' 'b' 'a' is the docstring, but the 'b' previously did not show up anywhere in the code object. Now there is the LOAD_CONST/POP_TOP pair. ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2005-10-21 04:54 Message: Logged In: YES user_id=4771 any reason why lambda functions have a __name__ of 'lambda' now instead of '<lambda>' ? ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2005-10-21 03:22 Message: Logged In: YES user_id=4771 import a as b, c the 'c' part gets completely forgotten and there is no 'IMPORT_NAME c' in the bytecode. ---------------------------------------------------------------------- Comment By: Armin Rigo (arigo) Date: 2005-10-21 03:13 Message: Logged In: YES user_id=4771 A scoping problem (comparing with the old compiler): class X: print hello The variable 'hello' is incorrectly looked up with LOAD_GLOBAL instead of LOAD_NAME. It causes a crash in PyPy in a case where the name 'hello' is stored into the class implicitely (via locals()). It can probably be discussed if the bug is in PyPy, but it is a difference in behavior. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1333982&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
