[Bug c++/99016] New: Internal compiler error from decltype of binary operator when one operand is a prvalue function call

[david at doublewise dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99016

            Bug ID: 99016
           Summary: Internal compiler error from decltype of binary
                    operator when one operand is a prvalue function call
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: david at doublewise dot net
  Target Milestone: ---

The following valid translation unit

```
struct integer {};

integer f();

int operator+(integer, integer);

using max_type = decltype(f() + f());
```

Causes gcc to crash with

```
<source>:7:35: internal compiler error: in build_over_call, at cp/call.c:9244
    7 | using max_type = decltype(f() + f());
      |                                   ^
0x1ce6f09 internal_error(char const*, ...)
        ???:0
0x6b6f43 fancy_abort(char const*, int, char const*)
        ???:0
0x6df89c build_new_method_call(tree_node*, tree_node*, vec<tree_node*, va_gc,
vl_embed>**, tree_node*, int, tree_node**, int)
        ???:0
0x6e1000 build_special_member_call(tree_node*, tree_node*, vec<tree_node*,
va_gc, vl_embed>**, tree_node*, int, int)
        ???:0
0x6e2760 build_new_op(op_location_t const&, tree_code, int, tree_node*,
tree_node*, tree_node*, tree_node**, int)
        ???:0
0x9c121d build_x_binary_op(op_location_t const&, tree_code, tree_node*,
tree_code, tree_node*, tree_code, tree_node**, int)
        ???:0
0x8de23d c_parse_file()
        ???:0
0xa5b7c2 c_common_parse_file()
        ???:0
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.
Compiler returned: 1
```

This worked in gcc 10.2. See it live: https://godbolt.org/z/oxj437