Infinite loop in compile

[llvmbot]

Bugzilla Link	8272
Resolution	FIXED
Resolved on	Dec 21, 2010 01:15
Version	unspecified
OS	All
Reporter	LLVM Bugzilla Contributor
CC	@DougGregor,@efriedma-quic,@ismail

Extended Description

Clang seems to infinite loop on the attached test case, from the GCC test suite:

ddunbar@giles:template (master)$ cat vtable2.C
// Use a small template instantiation depth to speed up testing
// { dg-options "-ftemplate-depth-5" }
// { dg-do compile }

// Origin: rullo.pat@tiscalinet.it
// Nathanael Nerode neroden@gcc.gnu.org
// Wolfgang Bangerth bangerth@dealii.org

// PR c++/6749: Infinite loop generating vtable.

template struct inner {};

template struct parent {
virtual void f() // { dg-error "instantiation depth" }
{ parent<inner > p; };
};

template struct parent;
ddunbar@giles:template (master)$ time xclang -c vtable2.C
C-c C-cAbort trap

real 0m55.865s
user 0m0.001s
sys 0m0.005s
ddunbar@giles:template (master)$

Sample shows that it is going crazy in the mangler.

[llvmbot]

This is mildly irritating because it makes the GCC test suite run much slower than need be (we have to wait for it to timeout).

[llvmbot]

This hangs with -fsyntax-only as well.

[DougGregor]

This is also rdar://problem/8137442.

[DougGregor]

*** Bug #8275 has been marked as a duplicate of this bug. ***

[ismail]

Bails out with an error on trunk:

vtable2.C:15:25: fatal error: recursive template instantiation exceeded maximum depth of 1024

[DougGregor]

Fixed by Nicholas in r120135.