coverage: Regression test for #117788

Without the workaround applied, this test will produce malformed mappings that
cause `llvm-cov` to fail.

(And if it does emit well-formed mappings, they should be obviously incorrect.)

1 files changed, 39 insertions, 0 deletions

diff --git a/tests/coverage/macro_name_span.coverage b/tests/coverage/macro_name_span.coverage
new file mode 100644
index 00000000000..cadf7024657
--- /dev/null
+++ b/tests/coverage/macro_name_span.coverage
@@ -0,0 +1,39 @@
+$DIR/auxiliary/macro_name_span_helper.rs:
+   LL|       |// edition: 2021
+   LL|       |
+   LL|       |#[macro_export]
+   LL|       |macro_rules! macro_that_defines_a_function {
+   LL|       |    (fn $name:ident () $body:tt) => {
+   LL|      1|        fn $name () -> () $body
+   LL|       |    }
+   LL|       |}
+   LL|       |
+   LL|       |// Non-executable comment.
+
+$DIR/macro_name_span.rs:
+   LL|       |// edition: 2021
+   LL|       |
+   LL|       |// Regression test for <https://github.com/rust-lang/rust/issues/117788>.
+   LL|       |// Under some circumstances, the heuristics that detect macro name spans can
+   LL|       |// get confused and produce incorrect spans beyond the bounds of the span
+   LL|       |// being processed.
+   LL|       |
+   LL|       |// aux-build: macro_name_span_helper.rs
+   LL|       |extern crate macro_name_span_helper;
+   LL|       |
+   LL|      1|fn main() {
+   LL|      1|    affected_function();
+   LL|      1|}
+   LL|       |
+   LL|       |macro_rules! macro_with_an_unreasonably_and_egregiously_long_name {
+   LL|       |    () => {
+   LL|       |        println!("hello");
+   LL|       |    };
+   LL|       |}
+   LL|       |
+   LL|       |macro_name_span_helper::macro_that_defines_a_function! {
+   LL|       |    fn affected_function() {
+   LL|       |        macro_with_an_unreasonably_and_egregiously_long_name!();
+   LL|       |    }
+   LL|       |}
+