[Bug c++/82159] [6/7/8 Regression] ICE: in assign_temp, at function.c:961

["chr at terma dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82159

--- Comment #8 from chr at terma dot com ---
(In reply to Jakub Jelinek from comment #7)
> If you can't provide a testcase, then we can't do anything with it.
> If the inability to provide a testcase is because it contains some
> proprietary stuff that can't be made public, you always have the option to
> reduce the testcase sufficiently that it is small enough to be releasable
> (perhaps after also changing identifiers).
> See https://gcc.gnu.org/wiki/A_guide_to_testcase_reduction for details how
> to do that.


Hello,

I've tried creduce, worked like a charm.

Following test case fails with -O0, but works with -O1-3.

Source file testcase.cpp:
-------------
class d;
template <typename f> class g { f e; };
class h : g<int[0]> {
public:
  template <typename i> d operator-(i);
};
class d : public h {
public:
  d(const d &);
};
class l : public d {
public:
  template <class j> l(j);
};
template <class an> class m {
public:
  typedef typename an::template n<m> ap;
};
template <class aq> class o { typename m<aq>::ap as; };
class D {
public:
  l av;
};
template <class aw> class p : aw {
public:
  template <typename ay, typename az> p(ay p1, az q) : aw(p1, q) {}
  D *ba;
  virtual void b() { aw::bc(ba); }
};
template <int, typename> class bj;
template <class> class bm {
public:
  typedef int bi;
  class bn {};
  template <class bo> class bp {
  public:
    l bq;
    bp(bi, bo q) : bq(q.av - 0) {}
  };
  bm(bi, bn);
};
template <typename> class r;
template <int bd, typename bv>
class r<bm<bj<bd, bv>>> : public bm<bj<bd, bv>>::bn {};
class s : public bm<bj<2, double>> {
  class t {
  public:
    t(bm *, int);
    void bc(D *p1) {
      bi a;
      bp<D>(a, *p1);
    }
  };

public:
  template <typename ay, typename az> s(ay p1, az q) : bm(p1, q) {}
  int cb;
  virtual int c() { p<t>(this, cb); }
};
template <typename> class H {
  r<bm<bj<2, double>>> cf;
  virtual s cg() { s(0, cf); }
};
template <template <class> class ci> class I {
public:
  I() { ci<int>(); }
};
class u {
public:
  template <class> class n : I<H> {};
};
void v() { o<u> k; }

int main() {
  return 0;
}

Steps to Repro:
-----------------
g++ -O0 testcase.cpp
testcase.cpp: In constructor ‘bm< <template-parameter-1-1> >::bp<bo>::bp(bm<
<template-parameter-1-1> >::bi, bo) [with bo = D; <template-parameter-1-1> =
bj<2, double>]’:
testcase.cpp:38:31: internal compiler error: in assign_temp, at function.c:968
     bp(bi, bo q) : bq(q.av - 0) {}
                               ^
Compiler used:
-----------------
The one included in Fedora 26 gcc version 7.2.1 20170915 (Red Hat 7.2.1-2)

gcc -v
Using built-in specs.
COLLECT_GCC=/usr/bin/gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/7/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap
--enable-languages=c,c++,objc,obj-c++,fortran,ada,go,lto --prefix=/usr
--mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared
--enable-threads=posix --enable-checking=release --enable-multilib
--with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions
--enable-gnu-unique-object --enable-linker-build-id
--with-gcc-major-version-only --with-linker-hash-style=gnu --enable-plugin
--enable-initfini-array --with-isl --enable-libmpx
--enable-offload-targets=nvptx-none --without-cuda-driver
--enable-gnu-indirect-function --with-tune=generic --with-arch_32=i686
--build=x86_64-redhat-linux
Thread model: posix
gcc version 7.2.1 20170915 (Red Hat 7.2.1-2) (GCC)