Warn on semicolon after `if`. (#2948)

* Warn on semicolon after `if`.

* add test result

---------

Co-authored-by: Yong He <yhe@nvidia.com>

2 files changed, 19 insertions, 0 deletions

diff --git a/tests/diagnostics/if-empty-body.slang b/tests/diagnostics/if-empty-body.slang
new file mode 100644
index 000000000..de8983352
--- /dev/null
+++ b/tests/diagnostics/if-empty-body.slang
@@ -0,0 +1,11 @@
+//DIAGNOSTIC_TEST(windows):SIMPLE:
+
+// Test that use of empty statement after an `if` leads to an warning.
+
+struct S {}
+
+void test()
+{
+	if (1+1==2);
+		return;
+}
\ No newline at end of file
diff --git a/tests/diagnostics/if-empty-body.slang.expected b/tests/diagnostics/if-empty-body.slang.expected
new file mode 100644
index 000000000..30915e39d
--- /dev/null
+++ b/tests/diagnostics/if-empty-body.slang.expected
@@ -0,0 +1,8 @@
+result code = 0
+standard error = {
+tests/diagnostics/if-empty-body.slang(9): warning 20101: potentially unintended empty statement at this location; use {} instead.
+    if (1+1==2);
+               ^
+}
+standard output = {
+}