Add more tests, fix span issue, improve diagnostics.

src/librustc_typeck/collect.rs

@@ -2560,6 +2560,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs {
     let whitelist = tcx.target_features_whitelist(LOCAL_CRATE);
 
     let mut inline_span = None;
+    let mut link_ordinal_span = None;
     for attr in attrs.iter() {
         if attr.check_name(sym::cold) {
             codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD;
@@ -2642,6 +2643,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs {
         } else if attr.check_name(sym::link_name) {
             codegen_fn_attrs.link_name = attr.value_str();
         } else if attr.check_name(sym::link_ordinal) {
+            link_ordinal_span = Some(attr.span);
             if let ordinal @ Some(_) = check_link_ordinal(tcx, attr) {
                 codegen_fn_attrs.link_ordinal = ordinal;
             }
@@ -2747,7 +2749,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs {
         codegen_fn_attrs.export_name = Some(name);
         codegen_fn_attrs.link_name = Some(name);
     }
-    check_link_name_xor_ordinal(tcx, &codegen_fn_attrs, inline_span);
+    check_link_name_xor_ordinal(tcx, &codegen_fn_attrs, link_ordinal_span);
 
     // Internal symbols to the standard library all have no_mangle semantics in
     // that they have defined symbol names present in the function name. This
@@ -2772,14 +2774,18 @@ fn check_link_ordinal(tcx: TyCtxt<'_>, attr: &ast::Attribute) -> Option<usize> {
             Some(*ordinal as usize)
         } else {
             let msg = format!(
-                "too large ordinal value in link_ordinal value: `{}`",
+                "ordinal value in `link_ordinal` is too large: `{}`",
                 &ordinal
             );
-            tcx.sess.span_err(attr.span, &msg);
+            tcx.sess.struct_span_err(attr.span, &msg)
+                .note("the value may not exceed `std::usize::MAX`")
+                .emit();
             None
         }
     } else {
-        tcx.sess.span_err(attr.span, "illegal ordinal format in link_ordinal");
+        tcx.sess.struct_span_err(attr.span, "illegal ordinal format in `link_ordinal`")
+            .note("an unsuffixed integer value, e.g., `1`, is expected")
+            .emit();
         None
     }
 }

src/test/ui/rfc-2627-raw-dylib/link-ordinal-and-name.rs

@@ -0,0 +1,12 @@
+#![feature(raw_dylib)]
+//~^ WARN the feature `raw_dylib` is incomplete and may cause the compiler to crash
+
+#[link(name="foo")]
+extern {
+    #[link_name="foo"]
+    #[link_ordinal(42)]
+    //~^ ERROR cannot use `#[link_name]` with `#[link_ordinal]`
+    fn foo();
+}
+
+fn main() {}

src/test/ui/rfc-2627-raw-dylib/link-ordinal-and-name.stderr

@@ -0,0 +1,16 @@
+warning: the feature `raw_dylib` is incomplete and may cause the compiler to crash
+  --> $DIR/link-ordinal-and-name.rs:1:12
+   |
+LL | #![feature(raw_dylib)]
+   |            ^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: cannot use `#[link_name]` with `#[link_ordinal]`
+  --> $DIR/link-ordinal-and-name.rs:7:5
+   |
+LL |     #[link_ordinal(42)]
+   |     ^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+

src/test/ui/rfc-2627-raw-dylib/link-ordinal-invalid-format.rs

@@ -0,0 +1,11 @@
+#![feature(raw_dylib)]
+//~^ WARN the feature `raw_dylib` is incomplete and may cause the compiler to crash
+
+#[link(name="foo")]
+extern {
+    #[link_ordinal("JustMonika")]
+    //~^ ERROR illegal ordinal format in `link_ordinal`
+    fn foo();
+}
+
+fn main() {}

src/test/ui/rfc-2627-raw-dylib/link-ordinal-invalid-format.stderr

@@ -0,0 +1,18 @@
+warning: the feature `raw_dylib` is incomplete and may cause the compiler to crash
+  --> $DIR/link-ordinal-invalid-format.rs:1:12
+   |
+LL | #![feature(raw_dylib)]
+   |            ^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: illegal ordinal format in `link_ordinal`
+  --> $DIR/link-ordinal-invalid-format.rs:6:5
+   |
+LL |     #[link_ordinal("JustMonika")]
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: an unsuffixed integer value, e.g., `1`, is expected
+
+error: aborting due to previous error
+

src/test/ui/rfc-2627-raw-dylib/link-ordinal-too-large.rs

@@ -0,0 +1,11 @@
+#![feature(raw_dylib)]
+//~^ WARN the feature `raw_dylib` is incomplete and may cause the compiler to crash
+
+#[link(name="foo")]
+extern {
+    #[link_ordinal(18446744073709551616)]
+    //~^ ERROR ordinal value in `link_ordinal` is too large: `18446744073709551616`
+    fn foo();
+}
+
+fn main() {}

src/test/ui/rfc-2627-raw-dylib/link-ordinal-too-large.stderr

@@ -0,0 +1,18 @@
+warning: the feature `raw_dylib` is incomplete and may cause the compiler to crash
+  --> $DIR/link-ordinal-too-large.rs:1:12
+   |
+LL | #![feature(raw_dylib)]
+   |            ^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: ordinal value in `link_ordinal` is too large: `18446744073709551616`
+  --> $DIR/link-ordinal-too-large.rs:6:5
+   |
+LL |     #[link_ordinal(18446744073709551616)]
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the value may not exceed `std::usize::MAX`
+
+error: aborting due to previous error
+