diff options
| -rw-r--r-- | Objects/stringobject.c | 53 |
1 files changed, 25 insertions, 28 deletions
diff --git a/Objects/stringobject.c b/Objects/stringobject.c index 992f3d9..ae08910 100644 --- a/Objects/stringobject.c +++ b/Objects/stringobject.c @@ -19,32 +19,29 @@ static PyStringObject *nullstring; #endif /* - PyString_FromStringAndSize() and PyString_FromString() try in certain cases - to share string objects. When the size of the string is zero, these - routines always return a pointer to the same string object; when the size - is one, they return a pointer to an already existing object if the contents - of the string is known. For PyString_FromString() this is always the case, - for PyString_FromStringAndSize() this is the case when the first argument - in not NULL. - - A common practice of allocating a string and then filling it in or changing - it must be done carefully. It is only allowed to change the contents of - the string if the object was gotten from PyString_FromStringAndSize() with - a NULL first argument, because in the future these routines may try to do - even more sharing of objects. - - The string in the `str' parameter does not have to be null-character - terminated. (Therefore it is safe to construct a substring by using - `PyString_FromStringAndSize(origstring, substrlen)'.) - - The parameter `size' denotes number of characters to allocate, not - counting the null terminating character. If the `str' argument is - not NULL, then it points to a of length `size'. For - PyString_FromString, this string must be null-terminated. - - The member `op->ob_size' denotes the number of bytes of data in the string, - not counting the null terminating character, and is therefore equal to the - `size' parameter. + For both PyString_FromString() and PyString_FromStringAndSize(), the + parameter `size' denotes number of characters to allocate, not counting any + null terminating character. + + For PyString_FromString(), the parameter `str' points to a null-terminated + string containing exactly `size' bytes. + + For PyString_FromStringAndSize(), the parameter the parameter `str' is + either NULL or else points to a string containing at least `size' bytes. For + PyString_FromStringAndSize(), the string in the `str' parameter does not + have to be null-terminated. (Therefore it is safe to construct a substring + by calling `PyString_FromStringAndSize(origstring, substrlen)'.) If `str' + is NULL then PyString_FromStringAndSize() will allocate `size+1' bytes + (setting the last byte to the null terminating character) and you can fill in + the data yourself. If `str' is non-NULL then the resulting PyString object + must be treated as immutable and you must not fill in nor alter the data + yourself, since the strings may be shared. + + The PyObject member `op->ob_size', which denotes the number of "extra items" + in a variable-size object, will contain the number of bytes allocated for + string data, not counting the null terminating character. It is therefore + equal to the equal to the `size' parameter (for PyString_FromStringAndSize()) + or the length of the string in the `str' parameter (for PyString_FromString()). */ PyObject * PyString_FromStringAndSize(const char *str, int size) @@ -605,7 +602,7 @@ string_print(PyStringObject *op, FILE *fp, int flags) /* figure out which quote to use; single is preferred */ quote = '\''; - if (strchr(op->ob_sval, '\'') && !strchr(op->ob_sval, '"')) + if (memchr(op->ob_sval, '\'', op->ob_size) && !memchr(op->ob_sval, '"', op->ob_size)) quote = '"'; fputc(quote, fp); @@ -649,7 +646,7 @@ string_repr(register PyStringObject *op) /* figure out which quote to use; single is preferred */ quote = '\''; - if (strchr(op->ob_sval, '\'') && !strchr(op->ob_sval, '"')) + if (memchr(op->ob_sval, '\'', op->ob_size) && !memchr(op->ob_sval, '"', op->ob_size)) quote = '"'; p = PyString_AS_STRING(v); |