Implement generalized initializer lists

[llvmbot]

Bugzilla Link	7069
Resolution	FIXED
Resolved on	Mar 04, 2012 09:41
Version	trunk
OS	Linux
Depends On	llvm/llvm-bugzilla-archive#12178
Blocks	llvm/llvm-bugzilla-archive#8390
Reporter	LLVM Bugzilla Contributor
CC	@asl,@DougGregor

Extended Description

I compiled Clang from SVN (tried revision 102493 and 103172) on ArchLinux using this: http://aur.archlinux.org/packages.php?ID=20222

Compiling my project failed and I identified the problem. Here is the simplest file where the problem arise:
#include
//#include

int main()
{
//std::cout << "Hello, world!\n";
}

Compiling gives:
clang++ test.cpp -o test
In file included from test.cpp:1:
/usr/include/c++/4.5.0/iomanip:63:12: error: expected expression
{ return { __mask }; }
^
/usr/include/c++/4.5.0/iomanip:93:12: error: expected expression
{ return { __mask }; }
^
/usr/include/c++/4.5.0/iomanip:124:12: error: expected expression
{ return { __base }; }
^
/usr/include/c++/4.5.0/iomanip:162:14: error: expected expression
{ return { __c }; }
^
/usr/include/c++/4.5.0/iomanip:192:12: error: expected expression
{ return { __n }; }
^
/usr/include/c++/4.5.0/iomanip:222:12: error: expected expression
{ return { __n }; }
^
6 errors generated.

[asl]

Please at least attach the preprocessed source, so others can reproduce your problems.

Thanks!

[llvmbot]

Simple test source not compiling
The source file can't be more simple. Nothing in main() and only the problematic include.

Is that what you meant?

[asl]

Created an attachment (id=4841) [details]
Simple test source not compiling

The source file can't be more simple. Nothing in main() and only the
problematic include.

Is that what you meant?
No. The testcase passes for me.

You might want to read e.g. http://gcc.gnu.org/bugs/ - almost everything listed there for gcc applies to clang bug submission as well.

[llvmbot]

Hoo I see sorry about that! First time reporting bugs for a compiler...

For GCC:

• the exact version of GCC;
  gcc version 4.5.0 (GCC)

• the system type;
  ArchLinux (?)

• the options given when GCC was configured/built;
  Using built-in specs.
  COLLECT_GCC=/usr/bin/gcc
  COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-unknown-linux-gnu/4.5.0/lto-wrapper
  Target: x86_64-unknown-linux-gnu
  Configured with: ../configure --prefix=/usr --enable-languages=c,c++,fortran,objc,obj-c++,ada --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu --enable-lto --enable-gnu-unique-object --disable-multilib --disable-libstdcxx-pch --with-system-zlib --with-ppl --with-cloog --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
  Thread model: posix

• the complete command line that triggers the bug;
  $ g++ test.cpp

• the compiler output (error messages, warnings, etc.); and
  None

• the preprocessed file (.i) that triggers the bug
  Coming

For Clang:

• the exact version:
  clang version 1.5 (trunk) AND 2.0 (trunk)
  Target: x86_64-unknown-linux-gnu
  Thread model: posix
  Revision 103172 from http://llvm.org/svn/llvm-project/llvm/trunk

• the options given when Clang was configured/built;
  ./configure --prefix=/usr --libdir=/usr/lib/llvm --sysconfdir=/etc --enable-libffi --disable-expensive-checks --disable-debug-runtime --disable-assertions --with-binutils-include=default --enable-pic --enable-optimized

• the complete command line that triggers the bug;
  $ clang++ test.cpp

• the compiler output (error messages, warnings, etc.); and
  In file included from test.cpp:1:
  /usr/include/c++/4.5.0/iomanip:63:12: error: expected expression
  { return { __mask }; }
  ^
  /usr/include/c++/4.5.0/iomanip:93:12: error: expected expression
  { return { __mask }; }
  ^
  /usr/include/c++/4.5.0/iomanip:124:12: error: expected expression
  { return { __base }; }
  ^
  /usr/include/c++/4.5.0/iomanip:162:14: error: expected expression
  { return { __c }; }
  ^
  /usr/include/c++/4.5.0/iomanip:192:12: error: expected expression
  { return { __n }; }
  ^
  /usr/include/c++/4.5.0/iomanip:222:12: error: expected expression
  { return { __n }; }
  ^
  6 errors generated.

• the preprocessed file (.i)
  Coming

I'll be attaching the preprocessed files in a sec.

[llvmbot]

G++ 4.5.0 output
$ g++ -v -save-temps test.cpp &> test_gcc450.log

[llvmbot]

G++ preprocessed file
From:
$ g++ -v -save-temps test.cpp

[llvmbot]

Clang++ 2.0 (r103172) output
clang++ -v -save-temps test.cpp &> test_clang20.log

[llvmbot]

Clang++ 2.0 (r103172) preprocessed file
$ clang++ -v -save-temps test.cpp

[llvmbot]

Let me know if you need any more information.

Thanx a lot!

[DougGregor]

Thank you! This code from the GCC 4.5.0 headers:

inline _Resetiosflags
resetiosflags(ios_base::fmtflags __mask)
{ return { __mask }; }

is not well-formed C++98/03 code. Rather, it's using the C++0x feature for generalized initializer lists. I've re-titled and recategorized the bug to reflect the actual issue: we're haven't started to implement this feature yet, so we can't compile code that uses it.

You'll need to use an older libstdc++ with Clang until we get to implementing C++0x.

[llvmbot]

Thanx for your fast anwser!

That's a shame... C++0x is not official yet... :S I always prefer compiling my code with -std=c++98 to make sure it is standard.

Do you know how I can tell clang to use my gcc 3.4.6 installation in /opt/gcc34?

[DougGregor]

There are a few options:

• Tweak lib/Frontend/InitHeaderSearch.cpp to put in the right path for your system
• Pass -nostdinc++ and then -I options to Clang to tell it where your headers are

[llvmbot]

Great! I'm now able to compile my project when adding:
-nostdinc++ -I/opt/gcc34/include/c++/3.4.6 -I/opt/gcc34/include/c++/3.4.6/x86_64-unknown-linux-gnu
as CFLAGS.

Thanx again.

[lattner]

should this be closed?

[DougGregor]

should this be closed?

It's effectively a task bug at this point, which is fine. Anyone wanting to track when we implement this feature can CC themselves. It's in the C++0x component so it doesn't show up as a bug in C++.