From 72f98e9b838ce73142e3bb89c4c7fde3266d475e Mon Sep 17 00:00:00 2001 From: Tim Peters Date: Tue, 8 May 2001 15:19:57 +0000 Subject: [PATCH] SF bug #422177: Results from .pyc differs from .py Store floats and doubles to full precision in marshal. Test that floats read from .pyc/.pyo closely match those read from .py. Declare PyFloat_AsString() in floatobject header file. Add new PyFloat_AsReprString() API function. Document the functions declared in floatobject.h. --- Include/floatobject.h | 27 +++++++++++++++++++++++---- Lib/test/test_import.py | 3 +++ Objects/floatobject.c | 6 ++++++ Python/marshal.c | 8 +++----- 4 files changed, 35 insertions(+), 9 deletions(-) diff --git a/Include/floatobject.h b/Include/floatobject.h index 1d0b50a620d..6e36a2f3187 100644 --- a/Include/floatobject.h +++ b/Include/floatobject.h @@ -20,13 +20,32 @@ extern DL_IMPORT(PyTypeObject) PyFloat_Type; #define PyFloat_Check(op) ((op)->ob_type == &PyFloat_Type) -extern DL_IMPORT(PyObject *) PyFloat_FromString(PyObject*, char**); -extern DL_IMPORT(PyObject *) PyFloat_FromDouble(double); -extern DL_IMPORT(double) PyFloat_AsDouble(PyObject *); +/* Return Python float from string PyObject. Second argument ignored on + input, and, if non-NULL, NULL is stored into *junk (this tried to serve a + purpose once but can't be made to work as intended). */ +extern DL_IMPORT(PyObject *) PyFloat_FromString(PyObject*, char** junk); -/* Macro, trading safety for speed */ +/* Return Python float from C double. */ +extern DL_IMPORT(PyObject *) PyFloat_FromDouble(double); + +/* Extract C double from Python float. The macro version trades safety for + speed. */ +extern DL_IMPORT(double) PyFloat_AsDouble(PyObject *); #define PyFloat_AS_DOUBLE(op) (((PyFloatObject *)(op))->ob_fval) +/* Write repr(v) into the char buffer argument, followed by null byte. The + buffer must be "big enough"; >= 100 is very safe. + PyFloat_AsReprString(buf, x) strives to print enough digits so that + PyFloat_FromString(buf) then reproduces x exactly. */ +extern DL_IMPORT(void) PyFloat_AsReprString(char*, PyFloatObject *v); + +/* Write str(v) into the char buffer argument, followed by null byte. The + buffer must be "big enough"; >= 100 is very safe. Note that it's + unusual to be able to get back the float you started with from + PyFloat_AsString's result -- use PyFloat_AsReprString() if you want to + preserve precision across conversions. */ +extern DL_IMPORT(void) PyFloat_AsString(char*, PyFloatObject *v); + #ifdef __cplusplus } #endif diff --git a/Lib/test/test_import.py b/Lib/test/test_import.py index a151defa21c..5419b5af7f7 100644 --- a/Lib/test/test_import.py +++ b/Lib/test/test_import.py @@ -13,6 +13,9 @@ except ImportError: else: raise TestFailed("import of RAnDoM should have failed (case mismatch)") +# Another brief digression to test the accuracy of manifest float constants. +import double_const # don't blink -- that *was* the test + sys.path.insert(0, os.curdir) source = TESTFN + ".py" diff --git a/Objects/floatobject.c b/Objects/floatobject.c index b1297980331..2f17d02837e 100644 --- a/Objects/floatobject.c +++ b/Objects/floatobject.c @@ -311,6 +311,12 @@ PyFloat_AsString(char *buf, PyFloatObject *v) PyFloat_AsStringEx(buf, v, PREC_STR); } +void +PyFloat_AsReprString(char *buf, PyFloatObject *v) +{ + PyFloat_AsStringEx(buf, v, PREC_REPR); +} + /* ARGSUSED */ static int float_print(PyFloatObject *v, FILE *fp, int flags) diff --git a/Python/marshal.c b/Python/marshal.c index 120c3fade67..7cd84f684f1 100644 --- a/Python/marshal.c +++ b/Python/marshal.c @@ -149,9 +149,8 @@ w_object(PyObject *v, WFILE *p) w_short(ob->ob_digit[i], p); } else if (PyFloat_Check(v)) { - extern void PyFloat_AsString(char *, PyFloatObject *); char buf[256]; /* Plenty to format any double */ - PyFloat_AsString(buf, (PyFloatObject *)v); + PyFloat_AsReprString(buf, (PyFloatObject *)v); n = strlen(buf); w_byte(TYPE_FLOAT, p); w_byte(n, p); @@ -159,20 +158,19 @@ w_object(PyObject *v, WFILE *p) } #ifndef WITHOUT_COMPLEX else if (PyComplex_Check(v)) { - extern void PyFloat_AsString(char *, PyFloatObject *); char buf[256]; /* Plenty to format any double */ PyFloatObject *temp; w_byte(TYPE_COMPLEX, p); temp = (PyFloatObject*)PyFloat_FromDouble( PyComplex_RealAsDouble(v)); - PyFloat_AsString(buf, temp); + PyFloat_AsReprString(buf, temp); Py_DECREF(temp); n = strlen(buf); w_byte(n, p); w_string(buf, n, p); temp = (PyFloatObject*)PyFloat_FromDouble( PyComplex_ImagAsDouble(v)); - PyFloat_AsString(buf, temp); + PyFloat_AsReprString(buf, temp); Py_DECREF(temp); n = strlen(buf); w_byte(n, p);