compiling some template classes and got error re anonymous struct not in named type

[Dean Z. Douthat]

Binary package hint: gcc-4.4

Ubuntu 9.10, gcc 4.4.1

Got error report about anonymous struct not inside of named type. This code compiled OK under Microsoft Visual Studio 2007. After error report, "confused by earlier errors, bailing out"

ProblemType: Crash
Architecture: amd64
Date: Tue Mar 23 00:05:01 2010
DistroRelease: Ubuntu 9.10
ExecutablePath: /usr/lib/gcc/x86_64-linux-gnu/4.4.1/cc1plus
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
NonfreeKernelModules: nvidia
Package: g++-4.4 4.4.1-4ubuntu9
ProcVersionSignature: Ubuntu 2.6.31-20.58-generic
SourcePackage: gcc-4.4
Uname: Linux 2.6.31-20-generic x86_64

[Matthias Klose (doko)]

seen with 4.3, 4.4, 4.5 and trunk:

Starting program: /scratch/packages/gcc/4.4/gcc-4.4-4.4.4/build/gcc/cc1plus -fpreprocessed ../../Vector3D.ii -quiet -dumpbase Vector3D.ii -mtune=generic -auxbase Vector3D -version -fpermissive -o /tmp/ccG8KwAM.s
GNU C++ (Debian 4.4.4-6) version 4.4.4 (x86_64-linux-gnu)
        compiled by GNU C version 4.4.4, GMP version 4.3.2, MPFR version 2.4.2-p1.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 98feda5ccf2f6c27a26b5ced57e2b3dd
In file included from Vector3D.cpp:4:
Vector3D.h: In member function 'Vec<FP_>& Vec<FP_>::operator^=(Vec<FP_>&)':
Vector3D.h:112: error: anonymous struct not inside named type
Vector3D.h: In member function 'Vec<FP_>& Vec<FP_>::operator^=(Vec<FP_>&) [with FP_ = double]':
Vector3D.cpp:19: instantiated from here
Vector3D.h:112: error: anonymous struct not inside named type

Program received signal SIGSEGV, Segmentation fault.
tsubst_copy_and_build (t=0x0, args=0x7ffff6112fc0, complain=tf_warning_or_error,
    in_decl=0x7ffff62b2c80, function_p=<value optimized out>,
    integral_constant_expression_p=<value optimized out>) at ../../src/gcc/cp/pt.c:11716
11716 if (BASELINK_P (member))
(gdb) p member
$1 = (tree) 0x0

[Matthias Klose (doko)]

Created attachment 20974
preprocessed source

[Matthias Klose (doko)]

ICE on error recovery, seen with 4.3, 4.4, 4.5, trunk

[Manu-gcc (manu-gcc)]

Confirmed in trunk. A reduce testcase would be helpful:

http://gcc.gnu.org/bugs/minimize.html

[Rguenth (rguenth)]

Reduced testcase (but with more and slightly different errors)

template<typename FP_> class Vec {
    Vec& operator^=(Vec& rhs) {
        union {
            struct {FP_ x,y,z;};
        };
        X = y*rhs.z() - z*rhs.y();
    }
    Vec& operator^(Vec& rhs) {
        return Vec(*this)^=rhs;
    }
};
Vec<double> v(3,4,12);
Vec<double>V(12,4,3);
Vec<double> c = v^V;

[Paolo-carlini (paolo-carlini)]

On it.

[stevenb (steven-gcc)]

Paolo, still on it?

[Paolo-carlini (paolo-carlini)]

On it (again ;)

[Paolo-k (paolo-k)]

Author: paolo
Date: Thu Jun 23 16:58:28 2011
New Revision: 175344

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=175344
Log:
/cp
2011-06-23 Paolo Carlini <email address hidden>

 PR c++/44625
 * decl2.c (build_anon_union_vars): Early return error_mark_node
 for a nested anonymous struct.

/testsuite
2011-06-23 Paolo Carlini <email address hidden>

 PR c++/44625
 * g++.dg/template/crash107.C: New.
 * g++.dg/template/error17.C: Adjust.

Added:
    trunk/gcc/testsuite/g++.dg/template/crash107.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/decl2.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/template/error17.C

[Paolo-carlini (paolo-carlini)]

Fixed for 4.7.0.