Farid Zaripov wrote:
-----Original Message-----
From: Martin Sebor [mailto:[EMAIL PROTECTED]
Sent: Sunday, July 16, 2006 11:46 PM
To: [email protected]
Subject: Re: design of testuite exceptions (was: Re: svn
commit: r418319 -
/incubator/stdcxx/trunk/tests/strings/21.string.io.cpp)
PS One thing to look into is formatting the text of the
exception's what string directly into the what_ buffer
instead dynamically allocating it only to free it later.
I believe rw_asnprintf has the ability to use the provided
buffer if it's large enough.
Unfortunately, rw_asnprintf cannot use buffer with automatic or static
storage.
rw_asnprintf calls rw_vasnprintf which calls _rw_bufcat. If the buffer
size is too small
the _rw_bufcat allocates the memory using malloc() and unconditionally
calls free() for
the old buffer.
_rw_bufcat() is supposed to fail when the requested amount of memory
exceeds the maximum (Buffer::maxsize). When the format string starts
with the %{*} directive, maxsize is set to the value of the first
argument in the argument list. So some of the pieces necessary to
make this possible are in place, but not all of them. In addition,
the code that is there is buggy and needs to be fixed to make the
feature usable. The bottom line is that something like
rw_snprintf (buffer, size, "...", ...) should do what we want. Let
me look into it.
Moreover the _rw_bufcat allocates the memory including
the guard block
(printf.cpp line 425) and even if the initial buffer was allocated using
malloc()
RW_ASSERT (printf.cpp line 461) will terminate the execution in the
debug
configurations.
Yes, but this won't happen once I fix the bugs.
Martin
