Address review comments

Adjust a few fulldeps and pretty-printing tests
Fix rebase

src/librustc_resolve/macros.rs

@@ -329,6 +329,9 @@ impl<'a, 'crateloader: 'a> base::Resolver for Resolver<'a, 'crateloader> {
             self.report_proc_macro_stub(invoc.span());
             return Err(Determinacy::Determined);
         } else if let Def::NonMacroAttr(attr_kind) = def {
+            // Note that not only attributes, but anything in macro namespace can result in a
+            // `Def::NonMacroAttr` definition (e.g. `inline!()`), so we must report the error
+            // below for these cases.
             let is_attr_invoc =
                 if let InvocationKind::Attr { .. } = invoc.kind { true } else { false };
             let path = invoc.path().expect("no path for non-macro attr");
@@ -604,7 +607,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
         // 3. Builtin attributes (closed, controlled).
 
         assert!(ns == TypeNS  || ns == MacroNS);
-        let force = force || record_used;
+        assert!(force || !record_used); // `record_used` implies `force`
         ident = ident.modern();
 
         // Names from inner scope that can't shadow names from outer scopes, e.g.
@@ -789,7 +792,10 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
 
         let determinacy = Determinacy::determined(force);
         if determinacy == Determinacy::Determined && is_attr {
-            // For attributes interpret determinate "no solution" as a custom attribute.
+            // For single-segment attributes interpret determinate "no resolution" as a custom
+            // attribute. (Lexical resolution implies the first segment and is_attr should imply
+            // the last segment, so we are certainly working with a single-segment attribute here.)
+            assert!(ns == MacroNS);
             let binding = (Def::NonMacroAttr(NonMacroAttrKind::Custom),
                            ty::Visibility::Public, ident.span, Mark::root())
                            .to_name_binding(self.arenas);

src/libsyntax/ext/expand.rs

@@ -516,6 +516,15 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
     }
 
     fn expand_invoc(&mut self, invoc: Invocation, ext: &SyntaxExtension) -> Option<AstFragment> {
+        if invoc.fragment_kind == AstFragmentKind::ForeignItems &&
+           !self.cx.ecfg.macros_in_extern_enabled() {
+            if let SyntaxExtension::NonMacroAttr { .. } = *ext {} else {
+                emit_feature_err(&self.cx.parse_sess, "macros_in_extern",
+                                 invoc.span(), GateIssue::Language,
+                                 "macro invocations in `extern {}` blocks are experimental");
+            }
+        }
+
         let result = match invoc.kind {
             InvocationKind::Bang { .. } => self.expand_bang_invoc(invoc, ext)?,
             InvocationKind::Attr { .. } => self.expand_attr_invoc(invoc, ext)?,
@@ -549,6 +558,8 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
         };
 
         if let NonMacroAttr { mark_used: false } = *ext {} else {
+            // Macro attrs are always used when expanded,
+            // non-macro attrs are considered used when the field says so.
             attr::mark_used(&attr);
         }
         invoc.expansion_data.mark.set_expn_info(ExpnInfo {
@@ -1482,34 +1493,14 @@ impl<'a, 'b> Folder for InvocationCollector<'a, 'b> {
                          foreign_item: ast::ForeignItem) -> SmallVector<ast::ForeignItem> {
         let (attr, traits, foreign_item) = self.classify_item(foreign_item);
 
-        let explain = if self.cx.ecfg.use_extern_macros_enabled() {
-            feature_gate::EXPLAIN_PROC_MACROS_IN_EXTERN
-        } else {
-            feature_gate::EXPLAIN_MACROS_IN_EXTERN
-        };
-
-        if attr.is_some() || !traits.is_empty()  {
-            if !self.cx.ecfg.macros_in_extern_enabled() &&
-               !self.cx.ecfg.custom_attribute_enabled() {
-                if let Some(ref attr) = attr {
-                    emit_feature_err(&self.cx.parse_sess, "macros_in_extern", attr.span,
-                                     GateIssue::Language, explain);
-                }
-            }
-
+        if attr.is_some() || !traits.is_empty() {
             let item = Annotatable::ForeignItem(P(foreign_item));
             return self.collect_attr(attr, traits, item, AstFragmentKind::ForeignItems)
                 .make_foreign_items();
         }
 
         if let ast::ForeignItemKind::Macro(mac) = foreign_item.node {
             self.check_attributes(&foreign_item.attrs);
-
-            if !self.cx.ecfg.macros_in_extern_enabled() {
-                emit_feature_err(&self.cx.parse_sess, "macros_in_extern", foreign_item.span,
-                                 GateIssue::Language, explain);
-            }
-
             return self.collect_bang(mac, foreign_item.span, AstFragmentKind::ForeignItems)
                 .make_foreign_items();
         }
@@ -1671,7 +1662,6 @@ impl<'feat> ExpansionConfig<'feat> {
         fn enable_custom_derive = custom_derive,
         fn enable_format_args_nl = format_args_nl,
         fn macros_in_extern_enabled = macros_in_extern,
-        fn custom_attribute_enabled = custom_attribute,
         fn proc_macro_mod = proc_macro_mod,
         fn proc_macro_gen = proc_macro_gen,
         fn proc_macro_expr = proc_macro_expr,

src/libsyntax/feature_gate.rs

@@ -1354,13 +1354,6 @@ pub const EXPLAIN_UNSIZED_TUPLE_COERCION: &'static str =
 pub const EXPLAIN_MACRO_AT_MOST_ONCE_REP: &'static str =
     "using the `?` macro Kleene operator for \"at most one\" repetition is unstable";
 
-pub const EXPLAIN_MACROS_IN_EXTERN: &'static str =
-    "macro invocations in `extern {}` blocks are experimental.";
-
-// mention proc-macros when enabled
-pub const EXPLAIN_PROC_MACROS_IN_EXTERN: &'static str =
-    "macro and proc-macro invocations in `extern {}` blocks are experimental.";
-
 struct PostExpansionVisitor<'a> {
     context: &'a Context<'a>,
 }
@@ -1969,7 +1962,6 @@ pub fn get_features(span_handler: &Handler, krate_attrs: &[ast::Attribute],
                     ).emit();
                 } else {
                     set(&mut features, mi.span);
-                    feature_checker.collect(&features, mi.span);
                     features.declared_lang_features.push((name, mi.span, None));
                 }
                 continue

src/test/compile-fail-fulldeps/proc-macro/issue-41211.rs

@@ -15,7 +15,7 @@
 
 #![feature(use_extern_macros)]
 #![emit_unchanged]
-//~^ ERROR: cannot find attribute macro `emit_unchanged` in this scope
+//~^ ERROR attribute `emit_unchanged` is currently unknown to the compiler
 extern crate issue_41211;
 use issue_41211::emit_unchanged;
 

src/test/compile-fail-fulldeps/proc-macro/macros-in-extern.rs

@@ -26,13 +26,13 @@ fn main() {
 #[link(name = "rust_test_helpers", kind = "static")]
 extern {
     #[no_output]
-    //~^ ERROR macro and proc-macro invocations in `extern {}` blocks are experimental.
+    //~^ ERROR macro invocations in `extern {}` blocks are experimental
     fn some_definitely_unknown_symbol_which_should_be_removed();
 
     #[nop_attr]
-    //~^ ERROR macro and proc-macro invocations in `extern {}` blocks are experimental.
+    //~^ ERROR macro invocations in `extern {}` blocks are experimental
     fn rust_get_test_int() -> isize;
 
     emit_input!(fn rust_dbg_extern_identity_u32(arg: u32) -> u32;);
-    //~^ ERROR macro and proc-macro invocations in `extern {}` blocks are experimental.
+    //~^ ERROR macro invocations in `extern {}` blocks are experimental
 }

src/test/compile-fail/macros-in-extern.rs

@@ -34,9 +34,9 @@ fn main() {
 #[link(name = "rust_test_helpers", kind = "static")]
 extern {
     returns_isize!(rust_get_test_int);
-    //~^ ERROR macro invocations in `extern {}` blocks are experimental.
+    //~^ ERROR macro invocations in `extern {}` blocks are experimental
     takes_u32_returns_u32!(rust_dbg_extern_identity_u32);
-    //~^ ERROR macro invocations in `extern {}` blocks are experimental.
+    //~^ ERROR macro invocations in `extern {}` blocks are experimental
     emits_nothing!();
-    //~^ ERROR macro invocations in `extern {}` blocks are experimental.
+    //~^ ERROR macro invocations in `extern {}` blocks are experimental
 }

src/test/pretty/attr-literals.rs

@@ -18,6 +18,6 @@ fn main() {
     #[align = 8]
     fn f() { }
 
-    #[vec(1, 2, 3)]
+    #[vector(1, 2, 3)]
     fn g() { }
 }

src/test/ui-fulldeps/resolve-error.rs

@@ -13,7 +13,7 @@
 // aux-build:attr_proc_macro.rs
 // aux-build:bang_proc_macro.rs
 
-#![feature(use_extern_macros)]
+#![feature(custom_attribute)]
 
 #[macro_use]
 extern crate derive_foo;
@@ -37,12 +37,10 @@ macro_rules! attr_proc_mac {
 //~^ ERROR cannot find
 struct Foo;
 
-#[attr_proc_macra]
-//~^ ERROR cannot find
+#[attr_proc_macra] // OK, interpreted as a custom attribute
 struct Bar;
 
-#[FooWithLongNan]
-//~^ ERROR cannot find
+#[FooWithLongNan]  // OK, interpreted as a custom attribute
 struct Asdf;
 
 #[derive(Dlone)]

src/test/ui-fulldeps/resolve-error.stderr

@@ -4,59 +4,47 @@ error: cannot find derive macro `FooWithLongNan` in this scope
 LL | #[derive(FooWithLongNan)]
    |          ^^^^^^^^^^^^^^ help: try: `FooWithLongName`
 
-error: cannot find attribute macro `attr_proc_macra` in this scope
-  --> $DIR/resolve-error.rs:40:3
-   |
-LL | #[attr_proc_macra]
-   |   ^^^^^^^^^^^^^^^ help: try: `attr_proc_macro`
-
-error: cannot find attribute macro `FooWithLongNan` in this scope
-  --> $DIR/resolve-error.rs:44:3
-   |
-LL | #[FooWithLongNan]
-   |   ^^^^^^^^^^^^^^
-
 error: cannot find derive macro `Dlone` in this scope
-  --> $DIR/resolve-error.rs:48:10
+  --> $DIR/resolve-error.rs:46:10
    |
 LL | #[derive(Dlone)]
    |          ^^^^^ help: try: `Clone`
 
 error: cannot find derive macro `Dlona` in this scope
-  --> $DIR/resolve-error.rs:52:10
+  --> $DIR/resolve-error.rs:50:10
    |
 LL | #[derive(Dlona)]
    |          ^^^^^ help: try: `Clona`
 
 error: cannot find derive macro `attr_proc_macra` in this scope
-  --> $DIR/resolve-error.rs:56:10
+  --> $DIR/resolve-error.rs:54:10
    |
 LL | #[derive(attr_proc_macra)]
    |          ^^^^^^^^^^^^^^^
 
 error: cannot find macro `FooWithLongNama!` in this scope
-  --> $DIR/resolve-error.rs:61:5
+  --> $DIR/resolve-error.rs:59:5
    |
 LL |     FooWithLongNama!();
    |     ^^^^^^^^^^^^^^^ help: you could try the macro: `FooWithLongNam`
 
 error: cannot find macro `attr_proc_macra!` in this scope
-  --> $DIR/resolve-error.rs:64:5
+  --> $DIR/resolve-error.rs:62:5
    |
 LL |     attr_proc_macra!();
    |     ^^^^^^^^^^^^^^^ help: you could try the macro: `attr_proc_mac`
 
 error: cannot find macro `Dlona!` in this scope
-  --> $DIR/resolve-error.rs:67:5
+  --> $DIR/resolve-error.rs:65:5
    |
 LL |     Dlona!();
    |     ^^^^^
 
 error: cannot find macro `bang_proc_macrp!` in this scope
-  --> $DIR/resolve-error.rs:70:5
+  --> $DIR/resolve-error.rs:68:5
    |
 LL |     bang_proc_macrp!();
    |     ^^^^^^^^^^^^^^^ help: you could try the macro: `bang_proc_macro`
 
-error: aborting due to 10 previous errors
+error: aborting due to 8 previous errors
 

src/test/compile-fail-fulldeps/proc-macro/proc-macro-custom-attr-mutex.rs → src/test/ui/custom-attribute-multisegment.rs

@@ -1,4 +1,4 @@
-// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,18 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// aux-build:attr_proc_macro.rs
-// ignore-tidy-linelength
+// Unresolved multi-segment attributes are not treated as custom.
 
-#![feature(custom_attribute)]
-//~^ ERROR Cannot use `#![feature(use_extern_macros)]` and `#![feature(custom_attribute)] at the same time
+#![feature(custom_attribute, proc_macro_path_invoc)]
 
-extern crate attr_proc_macro;
-use attr_proc_macro::attr_proc_macro;
+mod existent {}
 
-#[attr_proc_macro]
-fn foo() {}
-
-fn main() {
-    foo();
-}
+#[existent::nonexistent] //~ ERROR failed to resolve. Could not find `nonexistent` in `existent`
+fn main() {}

src/test/ui/custom-attribute-multisegment.stderr

@@ -0,0 +1,9 @@
+error[E0433]: failed to resolve. Could not find `nonexistent` in `existent`
+  --> $DIR/custom-attribute-multisegment.rs:17:13
+   |
+LL | #[existent::nonexistent] //~ ERROR failed to resolve. Could not find `nonexistent` in `existent`
+   |             ^^^^^^^^^^^ Could not find `nonexistent` in `existent`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0433`.

src/test/ui/feature-gate-macros_in_extern.rs

@@ -27,9 +27,9 @@ macro_rules! emits_nothing(
 #[link(name = "rust_test_helpers", kind = "static")]
 extern {
     returns_isize!(rust_get_test_int);
-    //~^ ERROR macro invocations in `extern {}` blocks are experimental.
+    //~^ ERROR macro invocations in `extern {}` blocks are experimental
     takes_u32_returns_u32!(rust_dbg_extern_identity_u32);
-    //~^ ERROR macro invocations in `extern {}` blocks are experimental.
+    //~^ ERROR macro invocations in `extern {}` blocks are experimental
     emits_nothing!();
-    //~^ ERROR macro invocations in `extern {}` blocks are experimental.
+    //~^ ERROR macro invocations in `extern {}` blocks are experimental
 }

src/test/ui/feature-gate-macros_in_extern.stderr

@@ -1,20 +1,20 @@
-error[E0658]: macro and proc-macro invocations in `extern {}` blocks are experimental. (see issue #49476)
+error[E0658]: macro invocations in `extern {}` blocks are experimental (see issue #49476)
   --> $DIR/feature-gate-macros_in_extern.rs:29:5
    |
 LL |     returns_isize!(rust_get_test_int);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: add #![feature(macros_in_extern)] to the crate attributes to enable
 
-error[E0658]: macro and proc-macro invocations in `extern {}` blocks are experimental. (see issue #49476)
+error[E0658]: macro invocations in `extern {}` blocks are experimental (see issue #49476)
   --> $DIR/feature-gate-macros_in_extern.rs:31:5
    |
 LL |     takes_u32_returns_u32!(rust_dbg_extern_identity_u32);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: add #![feature(macros_in_extern)] to the crate attributes to enable
 
-error[E0658]: macro and proc-macro invocations in `extern {}` blocks are experimental. (see issue #49476)
+error[E0658]: macro invocations in `extern {}` blocks are experimental (see issue #49476)
   --> $DIR/feature-gate-macros_in_extern.rs:33:5
    |
 LL |     emits_nothing!();