1 files changed, 70 insertions, 0 deletions
diff --git a/tests/coverage/mcdc/nested_if.rs b/tests/coverage/mcdc/nested_if.rs
new file mode 100644
index 00000000000..f5068b5dcc2
--- /dev/null
+++ b/tests/coverage/mcdc/nested_if.rs
@@ -0,0 +1,70 @@
+#![feature(coverage_attribute)]
+//@ edition: 2021
+//@ min-llvm-version: 18
+//@ compile-flags: -Zcoverage-options=mcdc
+//@ llvm-cov-flags: --show-branches=count --show-mcdc
+
+fn nested_if_in_condition(a: bool, b: bool, c: bool) {
+    if a && if b || c { true } else { false } {
+        say("yes");
+    } else {
+        say("no");
+    }
+}
+
+fn doubly_nested_if_in_condition(a: bool, b: bool, c: bool, d: bool) {
+    if a && if b || if c && d { true } else { false } { false } else { true } {
+        say("yes");
+    } else {
+        say("no");
+    }
+}
+
+fn nested_single_condition_decision(a: bool, b: bool) {
+    // Decision with only 1 decision should not be instrumented by MCDC because
+    // branch-coverage is equivalent to MCDC coverage in this case, and we don't
+    // want to waste bitmap space for this.
+    if a && if b { false } else { true } {
+        say("yes");
+    } else {
+        say("no");
+    }
+}
+
+fn nested_in_then_block_in_condition(a: bool, b: bool, c: bool, d: bool, e: bool) {
+    if a && if b || c { if d && e { true } else { false } } else { false } {
+        say("yes");
+    } else {
+        say("no");
+    }
+}
+
+#[coverage(off)]
+fn main() {
+    nested_if_in_condition(true, false, false);
+    nested_if_in_condition(true, true, true);
+    nested_if_in_condition(true, false, true);
+    nested_if_in_condition(false, true, true);
+
+    doubly_nested_if_in_condition(true, false, false, true);
+    doubly_nested_if_in_condition(true, true, true, true);
+    doubly_nested_if_in_condition(true, false, true, true);
+    doubly_nested_if_in_condition(false, true, true, true);
+
+    nested_single_condition_decision(true, true);
+    nested_single_condition_decision(true, false);
+    nested_single_condition_decision(false, false);
+
+    nested_in_then_block_in_condition(false, false, false, false, false);
+    nested_in_then_block_in_condition(true, false, false, false, false);
+    nested_in_then_block_in_condition(true, true, false, false, false);
+    nested_in_then_block_in_condition(true, false, true, false, false);
+    nested_in_then_block_in_condition(true, false, true, true, false);
+    nested_in_then_block_in_condition(true, false, true, false, true);
+    nested_in_then_block_in_condition(true, false, true, true, true);
+}
+
+#[coverage(off)]
+fn say(message: &str) {
+    core::hint::black_box(message);
+}