[#STDCXX-643] [IBM XLC++/AIX] std::exception incompatible with runtime library

C++ Standard Library

[IBM XLC++/AIX] std::exception incompatible with runtime library

Created: 02/Nov/07 10:27 PM Updated: 11/Jul/09 12:07 AM

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Component/s:

19. Diagnostics

Affects Version/s:

4.2.0

Fix Version/s:

5.0.0

Time Tracking:

Not Specified

Environment:

IBM XLC++/AIX

Issue Links:

Blocker

This issue blocks:

~~STDCXX-644~~ [IBM XLC++ 9.0/AIX 5.3] SIGHUP in 19.exceptions.mt

Severity:

Binary Incompatibility

Description

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A description of the problem is available here.
http://www.nabble.com/19.exceptions.mt.cpp-fails-on-AIX-tf4738595.html

Essentially we need to add a const char* member to std::exception for AIX. Unfortunately the fix is a binary incompatible with previous versions of stdcxx.

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Travis Vitek made changes - 02/Nov/07 10:31 PM

Field	Original Value	New Value
Severity	Incorrect Behavior	Binary Incompatibility

Martin Sebor made changes - 02/Nov/07 11:50 PM

Link

This issue blocks ~~STDCXX-644~~ [ ~~STDCXX-644~~ ]

Travis Vitek made changes - 27/Mar/08 07:33 AM

Comment

[ I've already suggested that we try to determine, at configuration time, the size and layout of the exception classes so that we can emulate them. If we don't go that far, we should at least add something that will check that the sizes match up and force the library to not compile if they don't. Something like this...

{noformat}
// looking for runtime library exceptions

#include <exception>
#include <typeinfo>

#include <stdio.h>

template <class T>
void run_test (const char* s)
{
  printf ("#define %-18s %u\n", s, sizeof (T));
}

int main ()
{
#define TEST(s,t) run_test<t>(#s)

  TEST (_RWSTD_EXCEPTION_SIZE , std::exception);
  TEST (_RWSTD_BAD_ALLOC_SIZE , std::bad_alloc);
  TEST (_RWSTD_BAD_CAST_SIZE , std::bad_cast);
  TEST (_RWSTD_BAD_EXCDEPTION_SIZE, std::bad_exception);
  TEST (_RWSTD_BAD_TYPEID_SIZE , std::bad_typeid);

  return 0;
}
{noformat}

Then we would put something like this near the top of exception.cpp

{noformat}
_RWSTD_NAMESPACE (__rw) {

static void
__rw_exception_compile_asserts ()
{
#define TEST(s,t) _RWSTD_COMPILE_ASSERT (s == sizeof (t))
  TEST (_RWSTD_EXCEPTION_SIZE , std::exception);
  TEST (_RWSTD_BAD_ALLOC_SIZE , std::bad_alloc);
  TEST (_RWSTD_BAD_CAST_SIZE , std::bad_cast);
  TEST (_RWSTD_BAD_EXCDEPTION_SIZE, std::bad_exception);
  TEST (_RWSTD_BAD_TYPEID_SIZE , std::bad_typeid);
#undef TEST
}

} // namespace rw
{noformat} ]

Travis Vitek made changes - 27/Mar/08 07:34 AM

Comment

[ I have already suggested that we determine the size and layout of the exception classes, and that we emulate them in our implementation. If we don't do that, then at the very least we should do a configuration test and a compile assert. That way the library won't build if our implementation doesn't match the runtime library. I would hope that something like this would work.

{noformat}
// looking for runtime library exceptions

#include <exception>
#include <typeinfo>

#include <stdio.h>

template <class T>
void run_test (const char* s)
{
  printf ("#define %-18s %u\n", s, sizeof (T));
}

int main ()
{
#define TEST(s,t) run_test<t>(s)

  TEST ("_RWSTD_EXCEPTION_SIZE" , std::exception);
  TEST ("_RWSTD_BAD_ALLOC_SIZE" , std::bad_alloc);
  TEST ("_RWSTD_BAD_CAST_SIZE" , std::bad_cast);
  TEST ("_RWSTD_BAD_EXCDEPTION_SIZE", std::bad_exception);
  TEST ("_RWSTD_BAD_TYPEID_SIZE" , std::bad_typeid);

  return 0;
}
{noformat}

And then, near the bottom of <exception>, we would write

{noformat}
_RWSTD_NAMESPACE (__rw) {

// used only to guarantee that we are binary compatible with the runtime library
inline void
__rw_exception_compile_asserts ()
{
  _RWSTD_COMPILE_ASSERT (_RWSTD_EXCEPTION_SIZE == sizeof (_STD::exception));
  _RWSTD_COMPILE_ASSERT (_RWSTD_BAD_ALLOC_SIZE == sizeof (_STD::bad_alloc));
  _RWSTD_COMPILE_ASSERT (_RWSTD_BAD_CAST_SIZE == sizeof (_STD::bad_cast));
  _RWSTD_COMPILE_ASSERT (_RWSTD_BAD_EXCEPTION_SIZE == sizeof (_STD::bad_exception));
  _RWSTD_COMPILE_ASSERT (_RWSTD_BAD_TYPEID_SIZE == sizeof (_STD::bad_typeid));
}

} // namespace rw
{noformat}
]

Martin Sebor made changes - 27/Mar/08 09:20 PM

Environment	AIX	IBM XLC++/AIX
Summary	std::exception declaration incompatible with implementation provided by runtime library on AIX	[IBM XLC++/AIX] std::exception incompatible with runtime library

Martin Sebor made changes - 17/Jul/08 11:54 PM

Assignee

Travis Vitek [ vitek ]

Travis Vitek made changes - 11/Jul/09 12:07 AM

Assignee

Travis Vitek [ vitek ]