https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119094
Bug ID: 119094
Summary: gcc uses all memory in recursive calls with
increasingly complex templates
Product: gcc
Version: 14.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: sandberg.sven at gmail dot com
Target Milestone: ---
The following program makes gcc use more and more memory until the system
imposes a limit (or crashes) (https://godbolt.org/z/WzdGMfc1s). (Warning: be
prepared to kill the compiler before the machine becomes unusable!)
```
template <class T, class U>
struct C {};
template <class T>
void explode() {
explode<C<T, T>>();
}
int main() {
explode<int>();
}
```
This may kill compile servers that don't have explicit guards against time or
memory over-use.
Other similar cases are guarded by -ftemplate-depth, but in this case the
template definition grows exponentially in the depth, so even small values for
the limit are ineffective in practice.
It would be better if there was a limit on the amount of memory used, or maybe
on the total size of a template, rather than just the depth.
clang seems to have the same problem.
