1 files changed, 61 insertions, 0 deletions
diff --git a/library/compiler-builtins/libm-test/tests/check_coverage.rs b/library/compiler-builtins/libm-test/tests/check_coverage.rs
new file mode 100644
index 00000000000..3b445a3de9d
--- /dev/null
+++ b/library/compiler-builtins/libm-test/tests/check_coverage.rs
@@ -0,0 +1,61 @@
+//! Ensure that `for_each_function!` isn't missing any symbols.
+
+use std::collections::HashSet;
+use std::env;
+use std::path::Path;
+use std::process::Command;
+
+macro_rules! callback {
+    (
+        fn_name: $name:ident,
+        attrs: [$($attr:meta),*],
+        extra: [$set:ident],
+    ) => {
+        let name = stringify!($name);
+        let new = $set.insert(name);
+        assert!(new, "duplicate function `{name}` in `ALL_OPERATIONS`");
+    };
+}
+
+#[test]
+fn test_for_each_function_all_included() {
+    let all_functions: HashSet<_> = include_str!("../../etc/function-list.txt")
+        .lines()
+        .filter(|line| !line.starts_with("#"))
+        .collect();
+
+    let mut tested = HashSet::new();
+
+    libm_macros::for_each_function! {
+        callback: callback,
+        extra: [tested],
+    };
+
+    let untested = all_functions.difference(&tested);
+    if untested.clone().next().is_some() {
+        panic!(
+            "missing tests for the following: {untested:#?} \
+            \nmake sure any new functions are entered in \
+            `ALL_OPERATIONS` (in `libm-macros`)."
+        );
+    }
+    assert_eq!(all_functions, tested);
+}
+
+#[test]
+fn ensure_list_updated() {
+    if libm_test::ci() {
+        // Most CI tests run in Docker where we don't have Python or Rustdoc, so it's easiest
+        // to just run the python file directly when it is available.
+        eprintln!("skipping test; CI runs the python file directly");
+        return;
+    }
+
+    let res = Command::new("python3")
+        .arg(Path::new(env!("CARGO_MANIFEST_DIR")).join("../etc/update-api-list.py"))
+        .arg("--check")
+        .status()
+        .unwrap();
+
+    assert!(res.success(), "May need to run `./etc/update-api-list.py`");
+}