Infinite loop printing "warning: missing braces around initializer" in g++

[nitrogen]

When compiling the attached malformed file with g++ -Wall, an infinite loop is entered that repeatedly prints the following message:

g++fail.cc:3:25: warning: missing braces around initializer for ‘char [0]’ [-Wmissing-braces]

This affects all versions of gcc installed on the machine: 4.4, 4.5, and 4.6. The expected behavior is that the warning is printed once, then g++ exits (clang behaves as expected).

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: g++-4.6 4.6.1-9ubuntu3
ProcVersionSignature: Ubuntu 3.0.0-16.28-generic 3.0.17
Uname: Linux 3.0.0-16-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Thu Mar 1 22:40:39 2012
ExecutablePath: /usr/bin/g++-4.6
InstallationMedia: Kubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
SourcePackage: gcc-4.6
UpgradeStatus: Upgraded to oneiric on 2011-11-09 (114 days ago)

[Matthias Klose (doko)]

confirmed. the fsf releases don't print anything, but don't terminate either. I see the repeated error message for Linaro builds only

[Doko-v (doko-v)]

seen on 4.6, 4.7 and trunk on x86_64-linux-gnu

int main()
{
        char argv[][0] = {"", 0};
}

$ g++ test.cc
doesn't terminate, or only if the VM get's exhausted.

[Daniel-kruegler (daniel-kruegler)]

I can confirm the problem for gcc 4.8 trunk for os=win32 arch=64bit systems

[Zhenqiang Chen (zhenqiang-chen)]

Thank you for the bug report. I've confirmed this with gcc-linaro-4.6-2012.08 and gcc-linaro-4.7-2012.08 on ARM:

./arm-linux-gnueabi-g++ -Wall t.cc
t.cc:3:32: warning: missing braces around initializer for ‘char [0]’ [-Wmissing-braces]
t.cc:3:32: warning: missing braces around initializer for ‘char [0]’ [-Wmissing-braces]
t.cc:3:32: warning: missing braces around initializer for ‘char [0]’ [-Wmissing-braces]
...

The compiler doesn't terminate.

[Paolo-carlini (paolo-carlini)]

On it.

[Paolo-k (paolo-k)]

Author: paolo
Date: Thu Oct 18 22:48:35 2012
New Revision: 192592

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=192592
Log:
/cp
2012-10-18 Paolo Carlini <email address hidden>

 PR c++/54501
 * decl.c (reshape_init_array_1): Avoid infinite loops.

/testsuite
2012-10-18 Paolo Carlini <email address hidden>

 PR c++/54501
 * g++.dg/init/array30.C: New.
 * g++.dg/init/array31.C: Likewise.

Added:
    trunk/gcc/testsuite/g++.dg/init/array30.C
    trunk/gcc/testsuite/g++.dg/init/array31.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/decl.c
    trunk/gcc/testsuite/ChangeLog

[Paolo-carlini (paolo-carlini)]

Fixed for 4.8.0.

[Michael Hope (michaelh1)]

Worth backporting to 4.7?

[Michael Collison (michael-collison)]

Fixed in linaro gcc 4.8.