[C++0x] Internal compiler error when using initializer lists

[Jan Blechta]

From https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50478
 Matti Rintala 2011-09-22 06:39:46 UTC

The following short program shows the problem:

#include <set>
#include <string>

int main() {
    std::set<std::string> s;
    s.insert( {"abc", "def", "hij"} ); // This line is the problem
}

> g++ -std=c++0x test.cc
test.cc: In function ‘int main()’:
test.cc:6:37: internal compiler error: in joust, at cp/call.c:7646

If I compile with -pedantic, the program compiles fine.

[Bitti (bitti)]

The following short program shows the problem:

#include <set>
#include <string>

int main() {
    std::set<std::string> s;
    s.insert( {"abc", "def", "hij"} ); // This line is the problem
}

> g++ -std=c++0x test.cc
test.cc: In function ‘int main()’:
test.cc:6:37: internal compiler error: in joust, at cp/call.c:7646

If I compile with -pedantic, the program compiles fine.

[Daniel-kruegler (daniel-kruegler)]

The problem seem to exist in 4.7.0 20110917 (experimental) as well, pointing to
joust, at cp/call.c:7960.

[Paolo-carlini (paolo-carlini)]

Insane, this doesn't happen for an initializer list of 1, 2, 4, or 5 elements. Happens with std::vector too, however. Should be rather easy to construct a reduced testcase including only <string>.

[Paolo-carlini (paolo-carlini)]

This is enough:

namespace std
{
  template<class _E>
    class initializer_list;

  template<typename _Key>
    struct set
    {
      void insert(const _Key&);
    };

  struct string
  {
    string(const string&, __SIZE_TYPE__, __SIZE_TYPE__ = -1);
    string(const char*);
    string(initializer_list<char>);
  };
}

int main()
{
  std::set<std::string> s;
  s.insert( { "abc", "def", "hij"} );
}

[Paolo-carlini (paolo-carlini)]

This is a more correct testcase, which also preserves the property of OT that -pedantic works around the issue. Note: removing the string constructor taking an initializer_list also works around the problem:

///////////////////

#include <initializer_list>

namespace std
{
  template<typename _Key>
    struct set
    {
      void insert(const _Key&);
      void insert(initializer_list<_Key>);
    };

  struct string
  {
    string(const string&, __SIZE_TYPE__, __SIZE_TYPE__ = -1);
    string(const char*);
    string(initializer_list<char>);
  };
}

int main()
{
  std::set<std::string> s;
  s.insert( { "abc", "def", "hij"} );
}

[Paolo-carlini (paolo-carlini)]

Seems fixed in mainline.

[Paolo-carlini (paolo-carlini)]

Fixed in 4.7.1 and mainline. Let's add the testcase and close the PR.

[Paolo-k (paolo-k)]

Author: paolo
Date: Wed Oct 10 09:12:19 2012
New Revision: 192295

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=192295
Log:
2012-10-10 Paolo Carlini <email address hidden>

 PR c++/50478
 * g++.dg/cpp0x/initlist67.C: New.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/initlist67.C
Modified:
    trunk/gcc/testsuite/ChangeLog

[Paolo-carlini (paolo-carlini)]

Done.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Matthias Klose (doko)]

won't fix for GCC 4.6. you can find backports of newer compilers in the ubuntu-toolchain-r/test PPA.