Add some tests for public-private dependencies.

Author: ehuss

tests/ui/privacy/pub-priv-dep/auxiliary/b.rs

@@ -0,0 +1,4 @@
+//@ aux-crate:priv:c=c.rs
+//@ compile-flags: -Zunstable-options
+
+extern crate c;

tests/ui/privacy/pub-priv-dep/auxiliary/c.rs

@@ -0,0 +1,4 @@
+//@ aux-crate:shared=shared.rs
+
+// This is public.
+extern crate shared;

tests/ui/privacy/pub-priv-dep/auxiliary/diamond_priv_dep.rs

@@ -0,0 +1,9 @@
+//@ aux-crate:shared=shared.rs
+
+extern crate shared;
+
+pub use shared::Shared;
+
+pub struct SharedInType {
+    pub f: Shared
+}

tests/ui/privacy/pub-priv-dep/auxiliary/diamond_pub_dep.rs

@@ -0,0 +1,9 @@
+//@ aux-crate:shared=shared.rs
+
+extern crate shared;
+
+pub use shared::Shared;
+
+pub struct SharedInType {
+    pub f: Shared
+}

tests/ui/privacy/pub-priv-dep/auxiliary/pm.rs

@@ -0,0 +1,22 @@
+//@ force-host
+//@ no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+use proc_macro::TokenStream;
+
+#[proc_macro]
+pub fn fn_like(input: TokenStream) -> TokenStream {
+    "".parse().unwrap()
+}
+
+#[proc_macro_derive(PmDerive)]
+pub fn pm_derive(item: TokenStream) -> TokenStream {
+    "".parse().unwrap()
+}
+
+#[proc_macro_attribute]
+pub fn pm_attr(attr: TokenStream, item: TokenStream) -> TokenStream {
+    "".parse().unwrap()
+}

tests/ui/privacy/pub-priv-dep/auxiliary/priv_dep.rs

@@ -1,2 +1,11 @@
 pub struct OtherType;
 pub trait OtherTrait {}
+
+#[macro_export]
+macro_rules! m {
+    () => {};
+}
+
+pub enum E {
+    V1
+}

tests/ui/privacy/pub-priv-dep/auxiliary/reexport.rs

@@ -0,0 +1,5 @@
+//@ aux-crate:shared=shared.rs
+
+extern crate shared;
+
+pub use shared::Shared;

tests/ui/privacy/pub-priv-dep/auxiliary/shared.rs

@@ -0,0 +1 @@
+pub struct Shared;

tests/ui/privacy/pub-priv-dep/diamond_deps.rs

@@ -0,0 +1,48 @@
+//@ aux-crate:priv:diamond_priv_dep=diamond_priv_dep.rs
+//@ aux-crate:diamond_pub_dep=diamond_pub_dep.rs
+//@ compile-flags: -Zunstable-options
+
+// A diamond dependency:
+//
+//           diamond_reepxort
+//                  /\
+//        (public) /  \ (PRIVATE)
+//                /    \
+//   diamond_pub_dep  diamond_priv_dep
+//                \    /
+//        (public) \  /  (public)
+//                  \/
+//                shared
+//
+// Where the pub and private crates reexport something from the shared crate.
+//
+// Checks the behavior when the same shared item appears in the public API,
+// depending on whether it comes from the public side or the private side.
+//
+// NOTE: compiletest does not support deduplicating shared dependencies.
+// However, it should work well enough for this test, the only downside is
+// that diamond_shared gets built twice.
+
+#![crate_type = "lib"]
+#![deny(exported_private_dependencies)]
+
+extern crate diamond_priv_dep;
+extern crate diamond_pub_dep;
+
+// FIXME: This should trigger.
+pub fn leaks_priv() -> diamond_priv_dep::Shared {
+    diamond_priv_dep::Shared
+}
+
+pub fn leaks_pub() -> diamond_pub_dep::Shared {
+    diamond_pub_dep::Shared
+}
+
+pub struct PrivInStruct {
+    pub f: diamond_priv_dep::SharedInType
+//~^ ERROR type `diamond_priv_dep::SharedInType` from private dependency 'diamond_priv_dep' in public interface
+}
+
+pub struct PubInStruct {
+    pub f: diamond_pub_dep::SharedInType
+}

tests/ui/privacy/pub-priv-dep/diamond_deps.stderr

@@ -0,0 +1,14 @@
+error: type `diamond_priv_dep::SharedInType` from private dependency 'diamond_priv_dep' in public interface
+  --> $DIR/diamond_deps.rs:42:5
+   |
+LL |     pub f: diamond_priv_dep::SharedInType
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/diamond_deps.rs:27:9
+   |
+LL | #![deny(exported_private_dependencies)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+