Segfault with performance-unnecessary-value-param check

[varqox]

Bugzilla Link	46510
Version	unspecified
OS	Linux
CC	@EugeneZelenko,@fberger,@irishrover

Extended Description

Running
clang-tidy -checks='performance-unnecessary-value-param' bug.cc
on the following code results in a segfault:

struct Foo {
Foo(const Foo&) {}
};

template
bool recur(unsigned x, T&& val) {
if (x == 0) {
return false;
}
return recur(x / 2, val);
}

void bar(Foo entry) {
recur(0, entry);
}

Both clang 10.0.0 and current trunk (clang 11) segfault (see https://godbolt.org/z/gzVMqr).

[irishrover]

It hangs inside ExprMutationAnalyzer trying to analyze a recursive function again and again.

[irishrover]

Simple workaround is to replace

Foo(const Foo&) {}
--->
Foo(const Foo&) = default;

[varqox]

Simple workaround is to replace

Foo(const Foo&) {}
--->
Foo(const Foo&) = default;

Thank you for noting that.
I tried to make the example as small as possible -- in the original code copy constructor wasn't trivial iirc.

[5chmidti]

This no longer reproduces, and has probably been fixed by #87954, which is part of LLVM19