https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61735
Bug ID: 61735
Summary: basic_string bug when type_size is char.
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: gkourtis at freemail dot gr
I use g++ and I have defined a custom allocator where the size_type is byte. I
am using it with basic_string to create custom strings.
The "basic_string.tcc" code behaves erroneously because in the code of
_S_create(size_type __capacity, size_type __old_capacity, const _Alloc&
__alloc)
the code checks for
const size_type __extra = __pagesize - __adj_size % __pagesize;
But all the arithmetic are byte arithmetic and so __pagesize that should have a
value 4096, becomes 0 (because 4096 is a multiple of 256 and bigger of 256) and
we have a "division by 0" exception (the code hangs).
I used the subsequent code to eliminate the unwanted effect:
#include <limits>
#define __pagesize_def 4096
{
if(std::numeric_limits<size_type>::max()>=__pagesize_def)
{ const size_type __extra = __pagesize - __adj_size % __pagesize; __capacity +=
__extra / sizeof(_CharT);
}
A little bit of discussion at:
http://stackoverflow.com/questions/24595837/bug-in-stdbasic-string-in-special-case-of-allocator
