https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118491
Bug ID: 118491
Summary: coroutines: ICE when co_awaiting l-value awaitable
from range-based loop.
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: email at miropalmu dot cc
Target Milestone: ---
The code snipped below (https://godbolt.org/z/hx3Ps9WqP)
produces ICE on gcc 15.0.1 20250115.
Interesting part is that ICE requires a range-based loop
and a l-value reference. It is also reproducible with
co_yielding a l-value.
```
#include <coroutine> // For std::suspend_always
struct task {
struct promise_type {
task get_return_object() { return {}; }
std::suspend_always initial_suspend() { return {}; }
std::suspend_always final_suspend() noexcept { return {}; }
std::suspend_always yield_value(double value) { return {}; }
void unhandled_exception() { throw; }
};
};
task do_task() {
const int arr[]{1, 2, 3};
// No ICE if classic loop and not range-based one.
// for (auto i = 0; i < 10; ++i) {
// No ICE if these are moved out of the loop.
// auto x = std::suspend_always{};
// co_await x;
for (auto _ : arr) {
auto x = std::suspend_always{};
co_await x;
// Alternatively:
// auto bar = 42.;
// co_yield bar;
// No ICE if r-values:
// co_await std::suspend_always{};
// co_yield 42.;
}
}
```
Output:
```
<source>: In function 'void do_task(_Z7do_taskv.Frame*)':
<source>:25:18: internal compiler error: in gimplify_var_or_parm_decl, at
gimplify.cc:3346
25 | co_await x;
| ^
0x28fd265 diagnostic_context::diagnostic_impl(rich_location*,
diagnostic_metadata const*, diagnostic_option_id, char const*, __va_list_tag
(*) [1], diagnostic_t)
???:0
0x2914066 internal_error(char const*, ...)
???:0
0xacb118 fancy_abort(char const*, int, char const*)
???:0
0x10fa6b9 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
???:0
0x10fb91c gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
???:0
0x110e4e3 gimplify_arg(tree_node**, gimple**, unsigned long, bool)
???:0
0xb6c837 cp_gimplify_expr(tree_node**, gimple**, gimple**)
???:0
0x10f97ab gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
???:0
0x10fc1e5 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
???:0
0x10fa3f2 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
???:0
0x10fbb85 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
???:0
0x10fb957 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
???:0
0x10fdd7a gimplify_stmt(tree_node**, gimple**)
???:0
0x10fb24b gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
???:0
0x10fbb85 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
???:0
0x10fdd7a gimplify_stmt(tree_node**, gimple**)
???:0
0x10fbb9c gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
???:0
0x10fdd7a gimplify_stmt(tree_node**, gimple**)
???:0
0x10fbb9c gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
???:0
0x10fdd7a gimplify_stmt(tree_node**, gimple**)
???:0
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Compiler returned: 1
```
