[cfe-dev] [Bug] Wrong Exception Handling : Destructor not called immediately

[suyog sarda]

Hi all,

This is a test g++ test case for checking correct exception handling.

























































*#ifdef __GXX_EXPERIMENTAL_CXX0X__#define NOEXCEPT_FALSE noexcept
(false)#else#define NOEXCEPT_FALSE#endifextern "C" void abort (); int
thrown;int as;struct a {  a () { ++as; }  ~a () NOEXCEPT_FALSE { --as; if
(thrown++ == 0) throw 42; }}; int f (a const&) { return 1; }int f (a
const&, a const&) { return 1; }int bs;int as_sav;struct b {  b (...) {
++bs; }  ~b ()   { --bs; as_sav = as; }};bool p;void g(){  if (p) throw
42;}int main () {  thrown = 0;  try {    b tmp(f (a(), a()));    g();  }
catch (...) {}  // We throw when the first a is destroyed, which should
destroy b before  // the other a.  if (as_sav != 1)    abort ();  thrown =
0;  try {    b tmp(f (a()));    g();  }    catch (...) {}   if (bs != 0)
abort ();} *

This Test Case aborts on ARM as well as X86 with clang latest trunk while
with g++ no aborts are seen .

Here, when first temporary object '*a'* gets destroyed, its destructor is
called where we throw an exception. This should immediately call destructor
of *'b'* and before calling constructor of second temporary object *'a'*.
Instead, with clang, it is waiting for second temporary object *'a'* to get
destroyed and then calling its own destructor.

In my opinion, the compiler is not generating correct landing pad for the
exception. Can someone please help in validating this reason? If it is a
genuine bug then i will file a bug and try to work out solution for it.

--
With regards,
Suyog Sarda
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