rewrite issue-30063

Author: Oneirical

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -103,7 +103,6 @@ run-make/issue-25581/Makefile
 run-make/issue-26006/Makefile
 run-make/issue-26092/Makefile
 run-make/issue-28595/Makefile
-run-make/issue-30063/Makefile
 run-make/issue-33329/Makefile
 run-make/issue-35164/Makefile
 run-make/issue-36710/Makefile

tests/run-make/issue-30063/Makefile

@@ -0,0 +1,36 @@
+// When rustc receives 4 codegen-units, an output path and an emit flag all simultaneously,
+// this could cause an annoying recompilation issue, uselessly lengthening the build process.
+// This test tries to reproduce this issue with varied emit flags - if it passes, the codegen-units
+// are being appropriately reset to 1 after each pass.
+// See https://github.com/rust-lang/rust/issues/30063
+
+//@ ignore-cross-compile
+
+use run_make_support::{rustc, tmp_dir};
+use std::fs;
+
+fn compile(emit: Option<&str>, output_dir: &str) {
+    let mut rustc = rustc().codegen_units(4).output(tmp_dir().join(output_dir)).input("foo.rs");
+    if let Some(emit) = emit {
+        rustc.emit(emit);
+    }
+    rustc.run();
+}
+
+fn main {
+    let flags = [
+        ("foo-output", None),
+        ("asm-output", Some("asm")),
+        ("bc-output", Some("llvm-bc")),
+        ("ir-output", Some("llvm-ir")),
+        ("link-output", Some("link")),
+        ("obj-output", Some("obj")),
+        ("dep-output", Some("dep-info")),
+        ("multi-output", Some("asm,obj"))
+    ];
+    for (output_dir, emit) in flags {
+        fs::remove_file(output_dir).unwrap_or_default();
+        compile(emit, output_dir);
+        fs::remove_file(output_dir);
+    }
+}