Add test case for stable import of invalid span information.

src/test/auxiliary/crate_with_invalid_spans.rs

@@ -0,0 +1,30 @@
+// Copyright 2015 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 = "rlib"]
+// no-prefer-dynamic
+
+// compile-flags: -g
+
+#[macro_use]
+mod crate_with_invalid_spans_macros;
+
+pub fn exported_generic<T>(x: T, y: u32) -> (T, u32) {
+    // Using the add1 macro will produce an invalid span, because the `y` passed
+    // to the macro will have a span from this file, but the rest of the code
+    // generated from the macro will have spans from the macro-defining file.
+    // The AST node for the (1 + y) expression generated by the macro will then
+    // take it's `lo` span bound from the `1` literal in the macro-defining file
+    // and it's `hi` bound from `y` in this file, which should be lower than the
+    // `lo` and even lower than the lower bound of the FileMap it is supposedly
+    // contained in because the FileMap for this file was allocated earlier than
+    // the FileMap of the macro-defining file.
+    return (x, add1!(y));
+}

src/test/auxiliary/crate_with_invalid_spans_macros.rs

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+// Copyright 2015 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.
+
+macro_rules! add1 {
+    ($e:expr) => ({
+        let a = 1 + $e;
+        let b = $e + 1;
+        a + b - 1
+    })
+}

src/test/run-pass/import-crate-with-invalid-spans.rs

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+// Copyright 2015 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.
+
+// aux-build:crate_with_invalid_spans.rs
+
+extern crate crate_with_invalid_spans;
+
+fn main() {
+    // The AST of `exported_generic` stored in crate_with_invalid_spans's
+    // metadata should contain an invalid span where span.lo > span.hi.
+    // Let's make sure the compiler doesn't crash when encountering this.
+    let _ = crate_with_invalid_spans::exported_generic(32u32, 7u32);
+}