[Bug target/43099] rethrowing leaks memory like a sieve

[Bug target/43099] rethrowing leaks memory like a sieve

[fxcoudert at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43099

Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |fxcoudert at gcc dot gnu.org
         Resolution|---                         |INVALID

--- Comment #10 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> ---
Either this was in the Apple unwinder, or this got fixed at some point. Current
trunk on darwin14 does not give memory leaks for the testcase, neither at -m32
nor at -m64.

[Bug target/43099] rethrowing leaks memory like a sieve

[pinskia at gcc dot gnu dot org]

------- Comment #9 from pinskia at gcc dot gnu dot org  2010-02-16 23:56 -------
No it does not return immediately.  You are reading the code so incorrectly
because you forgot to include the exception handling table.

The code difference for the source you provided is the same between 4.4 and the
trunk except different ordering of basic blocks.  At the tree level things are
more explicit though but otherwise it is the same code generation.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43099

[Bug target/43099] rethrowing leaks memory like a sieve

[dan dot colascione at gmail dot com]

------- Comment #8 from dan dot colascione at gmail dot com  2010-02-16 23:43 -------
Created an attachment (id=19895)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=19895&action=view)
bad code

The code generated seems to violate the ABI exception handling specification
here: http://www.codesourcery.com/public/cxx-abi/abi-eh.html

That document states that the caller of void __cxa_rethrow () must call
__cxa_end_catch(), but the code for current_ex() generated by gcc 4.5 just
returns immediately.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43099

[Bug target/43099] rethrowing leaks memory like a sieve

[dan dot colascione at gmail dot com]

------- Comment #7 from dan dot colascione at gmail dot com  2010-02-16 23:07 -------
Created an attachment (id=19894)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=19894&action=view)
Minimal testcase

The leak triggered by the return in the 'catch' statement in current_ex(). I've
bracketed the problematic code with an ifdef. Both catch clauses are necessary
to trigger the bug.


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dan dot colascione at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #19892|0                           |1
        is obsolete|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43099

[Bug target/43099] rethrowing leaks memory like a sieve

[pinskia at gcc dot gnu dot org]

------- Comment #6 from pinskia at gcc dot gnu dot org  2010-02-16 22:47 -------
Oh and on x86_64-linux-gnu with and without -m32, the program does not leak.


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pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|major                       |normal
   GCC host triplet|i386-apple-darwin10.2.0     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43099

[Bug target/43099] rethrowing leaks memory like a sieve

[dan dot colascione at gmail dot com]

------- Comment #5 from dan dot colascione at gmail dot com  2010-02-16 22:47 -------
But the bug does not appear when compiling with gcc 4.4, which uses the same
unwinder.


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dan dot colascione at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |major


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43099

[Bug target/43099] rethrowing leaks memory like a sieve

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2010-02-16 22:46 -------
This looks like a bug in Apple's unwinder and not a bug in GCC at all.  So I
think you should report this to Apple.


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pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|major                       |normal


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43099

[Bug target/43099] rethrowing leaks memory like a sieve

[dan dot colascione at gmail dot com]

------- Comment #3 from dan dot colascione at gmail dot com  2010-02-16 22:43 -------
Created an attachment (id=19893)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=19893&action=view)
valgrind output showing the leak


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43099

[Bug target/43099] rethrowing leaks memory like a sieve

[dan dot colascione at gmail dot com]

------- Comment #2 from dan dot colascione at gmail dot com  2010-02-16 22:41 -------
Also, compilation was done with just g++-mp-4.5 -m32 foo.cpp. The leak occurs
at all optimization levels.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43099

[Bug target/43099] rethrowing leaks memory like a sieve

[dan dot colascione at gmail dot com]

------- Comment #1 from dan dot colascione at gmail dot com  2010-02-16 22:40 -------
Created an attachment (id=19892)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=19892&action=view)
testcase


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43099