Enable macro modularization implicitly if one of "advanced" macro features is enabled

Do not mark all builtin attributes as used when macro modularization is enabled

Author: petrochenkov

src/libsyntax/feature_gate.rs

@@ -83,10 +83,14 @@ macro_rules! declare_features {
             }
 
             pub fn use_extern_macros(&self) -> bool {
-                // The `decl_macro`, `tool_attributes` and `custom_attributes`
-                // features imply `use_extern_macros`.
+                // A number of "advanced" macro features enable
+                // macro modularization (`use_extern_macros`) implicitly.
                 self.use_extern_macros || self.decl_macro ||
-                self.tool_attributes || self.custom_attribute
+                self.tool_attributes || self.custom_attribute ||
+                self.macros_in_extern || self.proc_macro_path_invoc ||
+                self.proc_macro_mod || self.proc_macro_expr ||
+                self.proc_macro_non_items || self.proc_macro_gen ||
+                self.stmt_expr_attributes
             }
         }
     };
@@ -700,7 +704,7 @@ pub fn is_builtin_attr_name(name: ast::Name) -> bool {
 }
 
 pub fn is_builtin_attr(attr: &ast::Attribute) -> bool {
-    BUILTIN_ATTRIBUTES.iter().any(|&(builtin_name, _, _)| attr.check_name(builtin_name)) ||
+    BUILTIN_ATTRIBUTES.iter().any(|&(builtin_name, _, _)| attr.path == builtin_name) ||
     attr.name().as_str().starts_with("rustc_")
 }
 

src/test/compile-fail-fulldeps/proc-macro/attr-invalid-exprs.rs

@@ -13,7 +13,7 @@
 
 //! Attributes producing expressions in invalid locations
 
-#![feature(use_extern_macros, stmt_expr_attributes, proc_macro_expr)]
+#![feature(stmt_expr_attributes, proc_macro_expr)]
 
 extern crate attr_stmt_expr;
 use attr_stmt_expr::{duplicate, no_output};

src/test/compile-fail-fulldeps/proc-macro/attr-stmt-expr.rs

@@ -11,7 +11,7 @@
 // aux-build:attr-stmt-expr.rs
 // ignore-stage1
 
-#![feature(use_extern_macros, proc_macro_expr)]
+#![feature(proc_macro_expr)]
 
 extern crate attr_stmt_expr;
 use attr_stmt_expr::{expect_let, expect_print_stmt, expect_expr, expect_print_expr};

src/test/compile-fail-fulldeps/proc-macro/issue-50493.rs

@@ -11,8 +11,6 @@
 // aux-build:issue_50493.rs
 // ignore-stage1
 
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate issue_50493;
 

src/test/compile-fail-fulldeps/proc-macro/lints_in_proc_macros.rs

@@ -11,7 +11,7 @@
 // aux-build:bang_proc_macro2.rs
 // ignore-stage1
 
-#![feature(use_extern_macros, proc_macro_non_items)]
+#![feature(proc_macro_non_items)]
 #![allow(unused_macros)]
 
 extern crate bang_proc_macro2;

src/test/compile-fail-fulldeps/proc-macro/proc-macro-custom-attr-mutex.rs

@@ -11,7 +11,7 @@
 // aux-build:attr_proc_macro.rs
 // ignore-tidy-linelength
 
-#![feature(use_extern_macros, custom_attribute)]
+#![feature(custom_attribute)]
 //~^ ERROR Cannot use `#![feature(use_extern_macros)]` and `#![feature(custom_attribute)] at the same time
 
 extern crate attr_proc_macro;

src/test/compile-fail-fulldeps/proc-macro/proc-macro-gates.rs

@@ -16,7 +16,7 @@
 // gate-test-proc_macro_mod
 // gate-test-proc_macro_gen
 
-#![feature(use_extern_macros, stmt_expr_attributes)]
+#![feature(stmt_expr_attributes)]
 
 extern crate proc_macro_gates as foo;
 

src/test/compile-fail-fulldeps/proc-macro/proc-macro-gates2.rs

@@ -10,7 +10,7 @@
 
 // aux-build:proc-macro-gates.rs
 
-#![feature(use_extern_macros, stmt_expr_attributes)]
+#![feature(stmt_expr_attributes)]
 
 extern crate proc_macro_gates as foo;
 

src/test/compile-fail/macro-with-seps-err-msg.rs

@@ -10,10 +10,6 @@
 
 // gate-test-use_extern_macros
 
-#![feature(proc_macro_path_invoc)]
-
 fn main() {
     globnar::brotz!(); //~ ERROR non-ident macro paths are experimental
-    #[derive(foo::Bar)] struct T; //~ ERROR non-ident macro paths are experimental
-    ::foo!(); //~ ERROR non-ident macro paths are experimental
 }

src/test/compile-fail/unknown-tool-name.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(use_extern_macros, proc_macro_path_invoc)]
+#![feature(proc_macro_path_invoc)]
 
 #[foo::bar] //~ ERROR failed to resolve. Use of undeclared type or module `foo`
 fn main() {}