Regression test for #40535

src/test/run-make/issue-40535/Makefile

@@ -0,0 +1,11 @@
+# The ICE occurred in the following situation:
+# * `foo` declares `extern crate bar, baz`, depends only on `bar` (forgetting `baz` in `Cargo.toml`)
+# * `bar` declares and depends on `extern crate baz`
+# * All crates built in metadata-only mode (`cargo check`)
+all:
+	# cc https://github.com/rust-lang/rust/issues/40623
+	$(RUSTC) baz.rs --emit=metadata --out-dir=$(TMPDIR)
+	$(RUSTC) bar.rs --emit=metadata --extern baz=$(TMPDIR)/libbaz.rmeta --out-dir=$(TMPDIR)
+	$(RUSTC) foo.rs --emit=metadata --extern bar=$(TMPDIR)/libbar.rmeta --out-dir=$(TMPDIR) 2>&1 | \
+	grep -vq "unexpectedly panicked"
+	# ^ Succeeds if it doesn't find the ICE message

src/test/run-make/issue-40535/bar.rs

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+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![crate_type = "lib"]
+
+extern crate baz;

src/test/run-make/issue-40535/baz.rs

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+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![crate_type = "lib"]

src/test/run-make/issue-40535/foo.rs

@@ -0,0 +1,14 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![crate_type = "lib"]
+
+extern crate bar;
+extern crate baz;