1 files changed, 121 insertions, 0 deletions
diff --git a/src/test/ui/proc-macro/expand-expr.rs b/src/test/ui/proc-macro/expand-expr.rs
new file mode 100644
index 000000000..d1146d970
--- /dev/null
+++ b/src/test/ui/proc-macro/expand-expr.rs
@@ -0,0 +1,121 @@
+// aux-build:expand-expr.rs
+
+extern crate expand_expr;
+
+use expand_expr::{
+    check_expand_expr_file, echo_pm, expand_expr_fail, expand_expr_is, recursive_expand,
+};
+
+// Check builtin macros can be expanded.
+
+expand_expr_is!(11u32, line!());
+expand_expr_is!(24u32, column!());
+
+expand_expr_is!("Hello, World!", concat!("Hello, ", "World", "!"));
+expand_expr_is!("int10floats5.3booltrue", concat!("int", 10, "floats", 5.3, "bool", true));
+expand_expr_is!("Hello", concat!(r##"Hello"##));
+
+expand_expr_is!("Included file contents\n", include_str!("auxiliary/included-file.txt"));
+expand_expr_is!(b"Included file contents\n", include_bytes!("auxiliary/included-file.txt"));
+
+expand_expr_is!(
+    "contents: Included file contents\n",
+    concat!("contents: ", include_str!("auxiliary/included-file.txt"))
+);
+
+// Correct value is checked for multiple sources.
+check_expand_expr_file!(file!());
+
+expand_expr_is!("hello", stringify!(hello));
+expand_expr_is!("10 + 20", stringify!(10 + 20));
+
+macro_rules! echo_tts {
+    ($($t:tt)*) => { $($t)* };  //~ ERROR: expected expression, found `$`
+}
+
+macro_rules! echo_lit {
+    ($l:literal) => {
+        $l
+    };
+}
+
+macro_rules! echo_expr {
+    ($e:expr) => {
+        $e
+    };
+}
+
+macro_rules! simple_lit {
+    ($l:literal) => {
+        expand_expr_is!($l, $l);
+        expand_expr_is!($l, echo_lit!($l));
+        expand_expr_is!($l, echo_expr!($l));
+        expand_expr_is!($l, echo_tts!($l));
+        expand_expr_is!($l, echo_pm!($l));
+        const _: () = {
+            macro_rules! mac {
+                () => {
+                    $l
+                };
+            }
+            expand_expr_is!($l, mac!());
+            expand_expr_is!($l, echo_expr!(mac!()));
+            expand_expr_is!($l, echo_tts!(mac!()));
+            expand_expr_is!($l, echo_pm!(mac!()));
+        };
+    };
+}
+
+simple_lit!("Hello, World");
+simple_lit!('c');
+simple_lit!(b'c');
+simple_lit!(10);
+simple_lit!(10.0);
+simple_lit!(10.0f64);
+simple_lit!(-3.14159);
+simple_lit!(-3.5e10);
+simple_lit!(0xFEED);
+simple_lit!(-0xFEED);
+simple_lit!(0b0100);
+simple_lit!(-0b0100);
+simple_lit!("string");
+simple_lit!(r##"raw string"##);
+simple_lit!(b"byte string");
+simple_lit!(br##"raw byte string"##);
+simple_lit!(true);
+simple_lit!(false);
+
+// Ensure char escapes aren't normalized by expansion
+simple_lit!("\u{0}");
+simple_lit!("\0");
+simple_lit!("\x00");
+simple_lit!('\u{0}');
+simple_lit!('\0');
+simple_lit!('\x00');
+simple_lit!(b"\x00");
+simple_lit!(b"\0");
+simple_lit!(b'\x00');
+simple_lit!(b'\0');
+
+// Extra tokens after the string literal aren't ignored
+expand_expr_fail!("string"; hello); //~ ERROR: expected one of `.`, `?`, or an operator, found `;`
+
+// Invalid expressions produce errors in addition to returning `Err(())`.
+expand_expr_fail!($); //~ ERROR: expected expression, found `$`
+expand_expr_fail!(echo_tts!($));
+expand_expr_fail!(echo_pm!($)); //~ ERROR: expected expression, found `$`
+
+// We get errors reported and recover during macro expansion if the macro
+// doesn't produce a valid expression.
+expand_expr_is!("string", echo_tts!("string"; hello)); //~ ERROR: macro expansion ignores token `hello` and any following
+expand_expr_is!("string", echo_pm!("string"; hello)); //~ ERROR: macro expansion ignores token `;` and any following
+
+// For now, fail if a non-literal expression is expanded.
+expand_expr_fail!(arbitrary_expression() + "etc");
+expand_expr_fail!(echo_tts!(arbitrary_expression() + "etc"));
+expand_expr_fail!(echo_expr!(arbitrary_expression() + "etc"));
+expand_expr_fail!(echo_pm!(arbitrary_expression() + "etc"));
+
+const _: u32 = recursive_expand!(); //~ ERROR: recursion limit reached while expanding `recursive_expand!`
+
+fn main() {}