[Bug c++/94155] New: internal compiler error: in gimplify_init_ctor_eval, at gimplify.c:4664

[Bug c++/94155] New: internal compiler error: in gimplify_init_ctor_eval, at gimplify.c:4664

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94155

            Bug ID: 94155
           Summary: internal compiler error: in gimplify_init_ctor_eval,
                    at gimplify.c:4664
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: redi at gcc dot gnu.org
                CC: mpolacek at gcc dot gnu.org
  Target Milestone: ---

I get an ICE with this use of parenthesized aggregate init (which needs
-std=gnu++2a to compile, and is a new feature so isn't a regression):

#include <utility>
void f()
{
  std::pair<int, std::pair<int, int>> p[2]( {1, {1, 1}}, {1, {1, 1}} );
}

t.cc:4:39: internal compiler error: in gimplify_init_ctor_eval, at
gimplify.c:4664
0x72e354 gimplify_init_ctor_eval
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:4664
0xda9064 gimplify_init_constructor
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:5107
0xda9cc5 gimplify_modify_expr_rhs
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:5370
0xda9eea gimplify_modify_expr
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:5721
0xdac158 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:13602
0xdafc36 gimplify_stmt(tree_node**, gimple**)
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:6823
0xdb87d8 gimplify_and_add(tree_node*, gimple**)
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:486
0xdb87d8 gimplify_decl_expr
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:1816
0xdad35d gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:13799
0xdafc36 gimplify_stmt(tree_node**, gimple**)
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:6823
0xdad1d9 gimplify_cleanup_point_expr
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:6565
0xdad1d9 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:13994
0xdafc36 gimplify_stmt(tree_node**, gimple**)
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:6823
0xdb09be gimplify_bind_expr
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:1424
0xdad324 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:13803
0xdafc36 gimplify_stmt(tree_node**, gimple**)
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:6823
0xdb16eb gimplify_body(tree_node*, bool)
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:14851
0xdb1ac7 gimplify_function_tree(tree_node*)
        /home/jwakely/src/gcc/gcc/gcc/gimplify.c:14995
0xc166d7 cgraph_node::analyze()
        /home/jwakely/src/gcc/gcc/gcc/cgraphunit.c:669
0xc1957a analyze_functions
        /home/jwakely/src/gcc/gcc/gcc/cgraphunit.c:1210
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

[Bug c++/94155] internal compiler error: in gimplify_init_ctor_eval, at gimplify.c:4664

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94155

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |needs-reduction

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The same variable definition works at namespace scope, I only get the ICE an
function scope.

My brief attempts to reduce it to remove std::pair made the ICE go away.

[Bug c++/94155] internal compiler error: in gimplify_init_ctor_eval, at gimplify.c:4664

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94155

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
           Assignee|unassigned at gcc dot gnu.org      |mpolacek at gcc dot gnu.org
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2020-03-12

[Bug c++/94155] internal compiler error: in gimplify_init_ctor_eval, at gimplify.c:4664

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94155

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Reduced:

template <typename T> struct A {
  int i;
  T t;
  constexpr A(int, T e) : i(), t(e) {}
};

void
f()
{
  A<A<int>> g[1]({1, {1, 1}});
}

We ICE because we don't satisfy:
 4662       /* ??? Here's to hoping the front end fills in all of the indices,
 4663          so we don't have to figure out what's missing ourselves.  */
 4664       gcc_assert (purpose);

[Bug c++/94155] internal compiler error: in gimplify_init_ctor_eval, at gimplify.c:4664

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94155

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Even simpler:

struct S { int i, j; };

struct A {
  S s;
  constexpr A(S e) : s(e) {}
};

void
f()
{
  A g[1]({{1, 1}});
}

[Bug c++/94155] internal compiler error: in gimplify_init_ctor_eval, at gimplify.c:4664

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94155

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:f84aded848f6fdd2704c9376263c6d1aee6bb0ca

commit r10-7568-gf84aded848f6fdd2704c9376263c6d1aee6bb0ca
Author: Marek Polacek <polacek@redhat.com>
Date:   Mon Mar 30 15:49:17 2020 -0400

    c++: Fix crash in gimplifier with paren init of aggregates [PR94155]

    Here we crash in the gimplifier because gimplify_init_ctor_eval doesn't
    expect null indexes for a constructor:

          /* ??? Here's to hoping the front end fills in all of the indices,
             so we don't have to figure out what's missing ourselves.  */
          gcc_assert (purpose);

    The indexes weren't filled because we never called reshape_init: for
    a constructor that represents parenthesized initialization of an
    aggregate we don't allow brace elision or designated initializers.

            PR c++/94155 - crash in gimplifier with paren init of aggregates.
            * init.c (build_vec_init): Fill in indexes.

            * g++.dg/cpp2a/paren-init22.C: New test.

[Bug c++/94155] internal compiler error: in gimplify_init_ctor_eval, at gimplify.c:4664

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94155

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed.