gccrs: format-args: Add basic test case

gcc/testsuite/ChangeLog:

	* rust/compile/format_args_basic_expansion.rs: New test.

1 files changed, 47 insertions, 0 deletions

diff --git a/gcc/testsuite/rust/compile/format_args_basic_expansion.rs b/gcc/testsuite/rust/compile/format_args_basic_expansion.rs
new file mode 100644
index 0000000..40bcd3c
--- /dev/null
+++ b/gcc/testsuite/rust/compile/format_args_basic_expansion.rs
@@ -0,0 +1,47 @@
+#![feature(rustc_attrs)]
+
+#[rustc_builtin_macro]
+macro_rules! format_args {
+    () => {};
+}
+
+#[lang = "sized"]
+trait Sized {}
+
+pub mod core {
+    pub mod fmt {
+        pub struct Formatter;
+        pub struct Result;
+
+        pub struct Arguments<'a>;
+
+        impl<'a> Arguments<'a> {
+            pub fn new_v1(_: &'a [&'static str], _: &'a [ArgumentV1<'a>]) -> Arguments<'a> {
+                Arguments
+            }
+        }
+
+        pub struct ArgumentV1<'a>;
+
+        impl<'a> ArgumentV1<'a> {
+            pub fn new<'b, T>(_: &'b T, _: fn(&T, &mut Formatter) -> Result) -> ArgumentV1 {
+                ArgumentV1
+            }
+        }
+
+        pub trait Display {
+            fn fmt(&self, _: &mut Formatter) -> Result;
+        }
+
+        impl Display for i32 {
+            fn fmt(&self, _: &mut Formatter) -> Result {
+                // { dg-warning "unused name .self." "" { target *-*-* } .-1 }
+                Result
+            }
+        }
+    }
+}
+
+fn main() {
+    let _formatted = format_args!("hello {}", 15);
+}