src/test/incremental/thinlto/cgu_keeps_identical_fn.rs

// This test is almost identical to `cgu_invalided_via_import`, except that
// the two versions of `inline_fn` are identical. Neither version of `inlined_fn`
// ends up with any spans in its LLVM bitecode, so LLVM is able to skip
// re-building any modules which import 'inlined_fn'

// revisions: cfail1 cfail2 cfail3
// compile-flags: -Z query-dep-graph -O
// build-pass (FIXME(62277): could be check-pass?)

#![feature(rustc_attrs)]
#![crate_type="rlib"]

#![rustc_expected_cgu_reuse(module="cgu_keeps_identical_fn-foo",
                            cfg="cfail2",
                            kind="no")]
#![rustc_expected_cgu_reuse(module="cgu_keeps_identical_fn-foo",
                            cfg="cfail3",
                            kind="post-lto")]

#![rustc_expected_cgu_reuse(module="cgu_keeps_identical_fn-bar",
                            cfg="cfail2",
                            kind="post-lto")]
#![rustc_expected_cgu_reuse(module="cgu_keeps_identical_fn-bar",
                            cfg="cfail3",
                            kind="post-lto")]

mod foo {

    // Trivial functions like this one are imported very reliably by ThinLTO.
    #[cfg(cfail1)]
    pub fn inlined_fn() -> u32 {
        1234
    }

    #[cfg(not(cfail1))]
    pub fn inlined_fn() -> u32 {
        1234
    }
}

pub mod bar {
    use foo::inlined_fn;

    pub fn caller() -> u32 {
        inlined_fn()
    }
}