rust/tests/run-coverage/unused_mod.coverage

    1|      0|pub fn never_called_function() {
    2|      0|    println!("I am never called");
    3|      0|}
[code coverage] Fix missing dead code in modules that are never called The issue here is that the logic used to determine which CGU to put the dead function stubs in doesn't handle cases where a module is never assigned to a CGU. The partitioning logic also caused issues in #85461 where inline functions were duplicated into multiple CGUs resulting in duplicate symbols. This commit fixes the issue by removing the complex logic used to assign dead code stubs to CGUs and replaces it with a much simplier model: we pick one CGU to hold all the dead code stubs. We pick a CGU which has exported items which increases the likelihood the linker won't throw away our dead functions and we pick the smallest to minimize the impact on compilation times for crates with very large CGUs. Fixes #86177 Fixes #85718 Fixes #79622 2021-12-20 16:36:56 -05:00			`1\| 0\|pub fn never_called_function() {`
			`2\| 0\| println!("I am never called");`
			`3\| 0\|}`