Auto merge of #6292 - ehuss:no-rmeta-hardlink, r=alexcrichton

Don't hardlink rmeta files.

`.rmeta` files shouldn't be needed in the main directory, and since rustc started outputing rmeta files for binaries, there are name collisions between bins and libs of the same name.

Partial fix for #5524.

src/cargo/core/compiler/context/compilation_files.rs

@@ -245,16 +245,12 @@ impl<'a, 'cfg: 'a> CompilationFiles<'a, 'cfg> {
         let mut unsupported = Vec::new();
         {
             if unit.mode.is_check() {
-                // This is not quite correct for non-lib targets.  rustc
-                // currently does not emit rmeta files, so there is nothing to
-                // check for!  See #3624.
+                // This may be confusing. rustc outputs a file named `lib*.rmeta`
+                // for both libraries and binaries.
                 let path = out_dir.join(format!("lib{}.rmeta", file_stem));
-                let hardlink = link_stem
-                    .clone()
-                    .map(|(ld, ls)| ld.join(format!("lib{}.rmeta", ls)));
                 ret.push(OutputFile {
                     path,
-                    hardlink,
+                    hardlink: None,
                     flavor: FileFlavor::Linkable,
                 });
             } else {

tests/testsuite/check.rs

@@ -2,7 +2,6 @@ use std::fmt::{self, Write};
 
 use glob::glob;
 use support::install::exe;
-use support::is_nightly;
 use support::paths::CargoPathExt;
 use support::registry::Package;
 use support::{basic_manifest, project};
@@ -573,39 +572,44 @@ fn check_artifacts() {
         .file("examples/ex1.rs", "fn main() {}")
         .file("benches/b1.rs", "")
         .build();
+
+    let assert_glob = |path: &str, count: usize| {
+        assert_eq!(
+            glob(&p.root().join(path).to_str().unwrap())
+                .unwrap()
+                .count(),
+            count
+        );
+    };
+
     p.cargo("check").run();
-    assert!(p.root().join("target/debug/libfoo.rmeta").is_file());
+    assert!(!p.root().join("target/debug/libfoo.rmeta").is_file());
     assert!(!p.root().join("target/debug/libfoo.rlib").is_file());
     assert!(!p.root().join("target/debug").join(exe("foo")).is_file());
+    assert_glob("target/debug/deps/libfoo-*.rmeta", 2);
 
     p.root().join("target").rm_rf();
     p.cargo("check --lib").run();
-    assert!(p.root().join("target/debug/libfoo.rmeta").is_file());
+    assert!(!p.root().join("target/debug/libfoo.rmeta").is_file());
     assert!(!p.root().join("target/debug/libfoo.rlib").is_file());
     assert!(!p.root().join("target/debug").join(exe("foo")).is_file());
+    assert_glob("target/debug/deps/libfoo-*.rmeta", 1);
 
     p.root().join("target").rm_rf();
     p.cargo("check --bin foo").run();
-    if is_nightly() {
-        // The nightly check can be removed once 1.27 is stable.
-        // Bins now generate `rmeta` files.
-        // See: https://github.com/rust-lang/rust/pull/49289
-        assert!(p.root().join("target/debug/libfoo.rmeta").is_file());
-    }
+    assert!(!p.root().join("target/debug/libfoo.rmeta").is_file());
     assert!(!p.root().join("target/debug/libfoo.rlib").is_file());
     assert!(!p.root().join("target/debug").join(exe("foo")).is_file());
+    assert_glob("target/debug/deps/libfoo-*.rmeta", 2);
 
     p.root().join("target").rm_rf();
     p.cargo("check --test t1").run();
     assert!(!p.root().join("target/debug/libfoo.rmeta").is_file());
     assert!(!p.root().join("target/debug/libfoo.rlib").is_file());
     assert!(!p.root().join("target/debug").join(exe("foo")).is_file());
-    assert_eq!(
-        glob(&p.root().join("target/debug/t1-*").to_str().unwrap())
-            .unwrap()
-            .count(),
-        0
-    );
+    assert_glob("target/debug/t1-*", 0);
+    assert_glob("target/debug/deps/libfoo-*.rmeta", 1);
+    assert_glob("target/debug/deps/libt1-*.rmeta", 1);
 
     p.root().join("target").rm_rf();
     p.cargo("check --example ex1").run();
@@ -617,18 +621,17 @@ fn check_artifacts() {
             .join(exe("ex1"))
             .is_file()
     );
+    assert_glob("target/debug/deps/libfoo-*.rmeta", 1);
+    assert_glob("target/debug/examples/libex1-*.rmeta", 1);
 
     p.root().join("target").rm_rf();
     p.cargo("check --bench b1").run();
     assert!(!p.root().join("target/debug/libfoo.rmeta").is_file());
     assert!(!p.root().join("target/debug/libfoo.rlib").is_file());
     assert!(!p.root().join("target/debug").join(exe("foo")).is_file());
-    assert_eq!(
-        glob(&p.root().join("target/debug/b1-*").to_str().unwrap())
-            .unwrap()
-            .count(),
-        0
-    );
+    assert_glob("target/debug/b1-*", 0);
+    assert_glob("target/debug/deps/libfoo-*.rmeta", 1);
+    assert_glob("target/debug/deps/libb1-*.rmeta", 1);
 }
 
 #[test]