Merge branch 'master' into box-alloc

3 files changed, 53 insertions, 2 deletions

diff --git a/src/test/incremental/thinlto/cgu_invalidated_via_import.rs b/src/test/incremental/thinlto/cgu_invalidated_via_import.rs
index 8160f8f3a99..5fe435d796f 100644
--- a/src/test/incremental/thinlto/cgu_invalidated_via_import.rs
+++ b/src/test/incremental/thinlto/cgu_invalidated_via_import.rs
@@ -33,7 +33,9 @@ mod foo {
 
     #[cfg(not(cfail1))]
     pub fn inlined_fn() -> u32 {
-        1234
+        // See `cgu_keeps_identical_fn.rs` for why this is different
+        // from the other version of this function.
+        12345
     }
 }
 
diff --git a/src/test/incremental/thinlto/cgu_keeps_identical_fn.rs b/src/test/incremental/thinlto/cgu_keeps_identical_fn.rs
new file mode 100644
index 00000000000..0fd5abee118
--- /dev/null
+++ b/src/test/incremental/thinlto/cgu_keeps_identical_fn.rs
@@ -0,0 +1,47 @@
+// This test is almost identical to `cgu_invalided_via_import`, except that
+// the two versions of `inline_fn` are identical. Neither version of `inlined_fn`
+// ends up with any spans in its LLVM bitecode, so LLVM is able to skip
+// re-building any modules which import 'inlined_fn'
+
+// revisions: cfail1 cfail2 cfail3
+// compile-flags: -Z query-dep-graph -O
+// build-pass (FIXME(62277): could be check-pass?)
+
+#![feature(rustc_attrs)]
+#![crate_type="rlib"]
+
+#![rustc_expected_cgu_reuse(module="cgu_keeps_identical_fn-foo",
+                            cfg="cfail2",
+                            kind="no")]
+#![rustc_expected_cgu_reuse(module="cgu_keeps_identical_fn-foo",
+                            cfg="cfail3",
+                            kind="post-lto")]
+
+#![rustc_expected_cgu_reuse(module="cgu_keeps_identical_fn-bar",
+                            cfg="cfail2",
+                            kind="post-lto")]
+#![rustc_expected_cgu_reuse(module="cgu_keeps_identical_fn-bar",
+                            cfg="cfail3",
+                            kind="post-lto")]
+
+mod foo {
+
+    // Trivial functions like this one are imported very reliably by ThinLTO.
+    #[cfg(cfail1)]
+    pub fn inlined_fn() -> u32 {
+        1234
+    }
+
+    #[cfg(not(cfail1))]
+    pub fn inlined_fn() -> u32 {
+        1234
+    }
+}
+
+pub mod bar {
+    use foo::inlined_fn;
+
+    pub fn caller() -> u32 {
+        inlined_fn()
+    }
+}
diff --git a/src/test/incremental/thinlto/independent_cgus_dont_affect_each_other.rs b/src/test/incremental/thinlto/independent_cgus_dont_affect_each_other.rs
index 24e5d2438bd..045f2011958 100644
--- a/src/test/incremental/thinlto/independent_cgus_dont_affect_each_other.rs
+++ b/src/test/incremental/thinlto/independent_cgus_dont_affect_each_other.rs
@@ -37,7 +37,9 @@ mod foo {
 
     #[cfg(not(cfail1))]
     pub fn inlined_fn() -> u32 {
-        1234
+        // See `cgu_keeps_identical_fn.rs` for why this is different
+        // from the other version of this function.
+        12345
     }
 }