run-make: port stdin-rustc to Rust-based rmake.rs

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -288,7 +288,6 @@ run-make/static-unwinding/Makefile
 run-make/staticlib-blank-lib/Makefile
 run-make/staticlib-dylib-linkage/Makefile
 run-make/std-core-cycle/Makefile
-run-make/stdin-non-utf8/Makefile
 run-make/suspicious-library/Makefile
 run-make/symbol-mangling-hashed/Makefile
 run-make/symbol-visibility/Makefile

tests/run-make/stdin-non-utf8/Makefile

@@ -1,6 +0,0 @@
-include ../tools.mk
-
-all:
-	cp non-utf8 $(TMPDIR)/non-utf.rs
-	cat $(TMPDIR)/non-utf.rs | $(RUSTC) - 2>&1 \
-		| $(CGREP) "error: couldn't read from stdin, as it did not contain valid UTF-8"

tests/run-make/stdin-non-utf8/non-utf8

@@ -1 +0,0 @@
-<EFBFBD>

tests/run-make/stdin-rustc/rmake.rs

@@ -0,0 +1,26 @@
+//! This test checks rustc `-` (stdin) support
+
+use run_make_support::{is_windows, rustc, tmp_dir};
+
+const HELLO_WORLD: &str = r#"
+fn main() {
+    println!("Hello world!");
+}
+"#;
+
+const NOT_UTF8: &[u8] = &[0xff, 0xff, 0xff];
+
+fn main() {
+    let out_dir = tmp_dir();
+
+    // echo $HELLO_WORLD | rustc -
+    rustc().arg("-").stdin(HELLO_WORLD).run();
+    assert!(
+        out_dir.join(if !is_windows() { "rust_out" } else { "rust_out.exe" }).try_exists().unwrap()
+    );
+
+    // echo $NOT_UTF8 | rustc -
+    let output = rustc().arg("-").stdin(NOT_UTF8).run_fail();
+    let stderr = String::from_utf8(output.stderr).unwrap();
+    assert!(stderr.contains("error: couldn't read from stdin, as it did not contain valid UTF-8"));
+}