From 3caca2326e04ea3c0d1f8c6a588e646d8201af38 Mon Sep 17 00:00:00 2001 From: Tim Peters Date: Thu, 6 Dec 2001 06:23:26 +0000 Subject: [PATCH] SF bug #488514: -Qnew needs work Big Hammer to implement -Qnew as PEP 238 says it should work (a global option affecting all instances of "/"). pydebug.h, main.c, pythonrun.c: define a private _Py_QnewFlag flag, true iff -Qnew is passed on the command line. This should go away (as the comments say) when true division becomes The Rule. This is deliberately not exposed to runtime inspection or modification: it's a one-way one-shot switch to pretend you're using Python 3. ceval.c: when _Py_QnewFlag is set, treat BINARY_DIVIDE as BINARY_TRUE_DIVIDE. test_{descr, generators, zipfile}.py: fiddle so these pass under -Qnew too. This was just a matter of s!/!//! in test_generators and test_zipfile. test_descr was trickier, as testbinop() is passed assumptions that "/" is the same as calling a "__div__" method; put a temporary hack there to call "__truediv__" instead when the method name is "__div__" and 1/2 evaluates to 0.5. Three standard tests still fail under -Qnew (on Windows; somebody please try the Linux tests with -Qnew too! Linux runs a whole bunch of tests Windows doesn't): test_augassign test_class test_coercion I can't stay awake longer to stare at this (be my guest). Offhand cures weren't obvious, nor was it even obvious that cures are possible without major hackery. Question: when -Qnew is in effect, should calls to __div__ magically change into calls to __truediv__? See "major hackery" at tail end of last paragraph . --- Include/pydebug.h | 4 ++++ Lib/test/test_descr.py | 5 +++++ Lib/test/test_generators.py | 12 ++++++------ Lib/zipfile.py | 4 ++-- Misc/NEWS | 21 ++++++++++++++++----- Modules/main.c | 5 ++++- Python/ceval.c | 25 ++++++++++++++----------- Python/pythonrun.c | 4 ++++ 8 files changed, 55 insertions(+), 25 deletions(-) diff --git a/Include/pydebug.h b/Include/pydebug.h index 9ecd8a00d23..d92161cd64a 100644 --- a/Include/pydebug.h +++ b/Include/pydebug.h @@ -16,6 +16,10 @@ extern DL_IMPORT(int) Py_TabcheckFlag; extern DL_IMPORT(int) Py_UnicodeFlag; extern DL_IMPORT(int) Py_IgnoreEnvironmentFlag; extern DL_IMPORT(int) Py_DivisionWarningFlag; +/* _XXX Py_QnewFlag should go away in 2.3. It's true iff -Qnew is passed, + on the command line, and is used in 2.2 by ceval.c to make all "/" divisions + true divisions (which they will be in 2.3). */ +extern DL_IMPORT(int) _Py_QnewFlag; /* this is a wrapper around getenv() that pays attention to Py_IgnoreEnvironmentFlag. It should be used for getting variables like diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py index 481ca0f7dfb..a0958df94e0 100644 --- a/Lib/test/test_descr.py +++ b/Lib/test/test_descr.py @@ -23,6 +23,11 @@ def testunop(a, res, expr="len(a)", meth="__len__"): def testbinop(a, b, res, expr="a+b", meth="__add__"): if verbose: print "checking", expr dict = {'a': a, 'b': b} + + # XXX Hack so this passes before 2.3 when -Qnew is specified. + if meth == "__div__" and 1/2 == 0.5: + meth = "__truediv__" + vereq(eval(expr, dict), res) t = type(a) m = getattr(t, meth) diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py index 118b1d9fce1..2c319e5db98 100644 --- a/Lib/test/test_generators.py +++ b/Lib/test/test_generators.py @@ -182,7 +182,7 @@ Specification: Return Specification: Generators and Exception Propagation >>> def f(): - ... return 1/0 + ... return 1//0 >>> def g(): ... yield f() # the zero division exception propagates ... yield 42 # and we'll never get here @@ -206,7 +206,7 @@ Specification: Try/Except/Finally ... yield 1 ... try: ... yield 2 - ... 1/0 + ... 1//0 ... yield 3 # never get here ... except ZeroDivisionError: ... yield 4 @@ -253,7 +253,7 @@ Guido's binary tree example. ... n = len(list) ... if n == 0: ... return [] - ... i = n / 2 + ... i = n // 2 ... return Tree(list[i], tree(list[:i]), tree(list[i+1:])) >>> # Show it off: create a tree. @@ -691,7 +691,7 @@ SyntaxError: 'yield' not allowed in a 'try' block with a 'finally' clause (>> def f(): ... try: ... try: -... 1/0 +... 1//0 ... except ZeroDivisionError: ... yield 666 # bad because *outer* try has finally ... except: @@ -708,7 +708,7 @@ But this is fine: ... try: ... try: ... yield 12 -... 1/0 +... 1//0 ... except ZeroDivisionError: ... yield 666 ... except: @@ -751,7 +751,7 @@ SyntaxError: invalid syntax ... pass ... elif 0: ... try: -... 1/0 +... 1//0 ... except SyntaxError: ... pass ... else: diff --git a/Lib/zipfile.py b/Lib/zipfile.py index 4b59ac6dea6..0efcad3a8a4 100644 --- a/Lib/zipfile.py +++ b/Lib/zipfile.py @@ -117,7 +117,7 @@ class ZipInfo: """Return the per-file header as a string.""" dt = self.date_time dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2] - dostime = dt[3] << 11 | dt[4] << 5 | dt[5] / 2 + dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2) if self.flag_bits & 0x08: # Set these to zero because we write them after the file data CRC = compress_size = file_size = 0 @@ -468,7 +468,7 @@ class ZipFile: count = count + 1 dt = zinfo.date_time dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2] - dostime = dt[3] << 11 | dt[4] << 5 | dt[5] / 2 + dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2) centdir = struct.pack(structCentralDir, stringCentralDir, zinfo.create_version, zinfo.create_system, zinfo.extract_version, zinfo.reserved, diff --git a/Misc/NEWS b/Misc/NEWS index eabe9b60f56..db38eca9730 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -39,6 +39,13 @@ Type/class unification and new-style classes Core and builtins +- -Qnew now works as documented in PEP 238: when -Qnew is passed on + the command line, all occurrences of "/" use true division instead + of classic division. See the PEP for details. Note that "all" + means all instances in library and 3rd-party modules, as well as in + your own code. As the PEP says, -Qnew is intended for use only in + educational environments with control over the libraries in use. + Extension modules - gc.get_referents was renamed to gc.get_referrers. @@ -712,11 +719,15 @@ Core warnings are issued. Using -Qwarn issues a run-time warning about all uses of classic division for int and long arguments; -Qwarnall also warns about classic division for float and complex arguments - (for use with fixdiv.py). Using -Qnew is questionable; it turns on - new division by default, but only in the __main__ module. You can - usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the - __main__ module new division, and warns about classic division - everywhere else. + (for use with fixdiv.py). + [Note: the remainder of this paragraph (preserved below) became + obsolete in 2.2c1 -- -Qnew has global effect in 2.2] + + Using -Qnew is questionable; it turns on new division by default, but + only in the __main__ module. You can usefully combine -Qwarn or + -Qwarnall and -Qnew: this gives the __main__ module new division, and + warns about classic division everywhere else. + - Many built-in types can now be subclassed. This applies to int, long, float, str, unicode, and tuple. (The types complex, list and diff --git a/Modules/main.c b/Modules/main.c index eea848fff52..5f71ee2c0aa 100644 --- a/Modules/main.c +++ b/Modules/main.c @@ -169,8 +169,11 @@ Py_Main(int argc, char **argv) break; } if (strcmp(_PyOS_optarg, "new") == 0) { - /* XXX This only affects __main__ */ + /* This only affects __main__ */ cf.cf_flags |= CO_FUTURE_DIVISION; + /* And this tells the eval loop to treat + BINARY_DIVIDE as BINARY_TRUE_DIVIDE */ + _Py_QnewFlag = 1; break; } fprintf(stderr, diff --git a/Python/ceval.c b/Python/ceval.c index 535851775f4..76424e107c8 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -903,9 +903,22 @@ eval_frame(PyFrameObject *f) break; case BINARY_DIVIDE: + if (!_Py_QnewFlag) { + w = POP(); + v = POP(); + x = PyNumber_Divide(v, w); + Py_DECREF(v); + Py_DECREF(w); + PUSH(x); + if (x != NULL) continue; + break; + } + /* -Qnew is in effect: fall through to + BINARY_TRUE_DIVIDE */ + case BINARY_TRUE_DIVIDE: w = POP(); v = POP(); - x = PyNumber_Divide(v, w); + x = PyNumber_TrueDivide(v, w); Py_DECREF(v); Py_DECREF(w); PUSH(x); @@ -922,16 +935,6 @@ eval_frame(PyFrameObject *f) if (x != NULL) continue; break; - case BINARY_TRUE_DIVIDE: - w = POP(); - v = POP(); - x = PyNumber_TrueDivide(v, w); - Py_DECREF(v); - Py_DECREF(w); - PUSH(x); - if (x != NULL) continue; - break; - case BINARY_MODULO: w = POP(); v = POP(); diff --git a/Python/pythonrun.c b/Python/pythonrun.c index 628058b8b88..a8ad84503df 100644 --- a/Python/pythonrun.c +++ b/Python/pythonrun.c @@ -64,6 +64,10 @@ int Py_UseClassExceptionsFlag = 1; /* Needed by bltinmodule.c: deprecated */ int Py_FrozenFlag; /* Needed by getpath.c */ int Py_UnicodeFlag = 0; /* Needed by compile.c */ int Py_IgnoreEnvironmentFlag; /* e.g. PYTHONPATH, PYTHONHOME */ +/* _XXX Py_QnewFlag should go away in 2.3. It's true iff -Qnew is passed, + on the command line, and is used in 2.2 by ceval.c to make all "/" divisions + true divisions (which they will be in 2.3). */ +int _Py_QnewFlag = 0; static int initialized = 0;