Rollup merge of rust-lang#62133 - petrochenkov:norustc, r=eddyb

Feature gate `rustc` attributes harder

Fixes rust-lang#62116

src/libcore/lib.rs

@@ -74,6 +74,7 @@
 #![feature(concat_idents)]
 #![feature(const_fn)]
 #![feature(const_fn_union)]
+#![feature(custom_inner_attributes)]
 #![feature(doc_cfg)]
 #![feature(doc_spotlight)]
 #![feature(extern_types)]

src/librustc_resolve/macros.rs

@@ -19,9 +19,8 @@ use syntax::ext::base::{MacroKind, SyntaxExtension};
 use syntax::ext::expand::{AstFragment, Invocation, InvocationKind};
 use syntax::ext::hygiene::Mark;
 use syntax::ext::tt::macro_rules;
-use syntax::feature_gate::{
-    feature_err, is_builtin_attr_name, AttributeGate, GateIssue, Stability, BUILTIN_ATTRIBUTES,
-};
+use syntax::feature_gate::{feature_err, emit_feature_err, is_builtin_attr_name};
+use syntax::feature_gate::{AttributeGate, GateIssue, Stability, BUILTIN_ATTRIBUTES};
 use syntax::symbol::{Symbol, kw, sym};
 use syntax::visit::Visitor;
 use syntax::util::lev_distance::find_best_match_for_name;
@@ -298,12 +297,25 @@ impl<'a> Resolver<'a> {
         let res = self.resolve_macro_to_res_inner(path, kind, parent_scope, trace, force);
 
         // Report errors and enforce feature gates for the resolved macro.
+        let features = self.session.features_untracked();
         if res != Err(Determinacy::Undetermined) {
             // Do not report duplicated errors on every undetermined resolution.
             for segment in &path.segments {
                 if let Some(args) = &segment.args {
                     self.session.span_err(args.span(), "generic arguments in macro path");
                 }
+                if kind == MacroKind::Attr && !features.rustc_attrs &&
+                   segment.ident.as_str().starts_with("rustc") {
+                    let msg = "attributes starting with `rustc` are \
+                               reserved for use by the `rustc` compiler";
+                    emit_feature_err(
+                        &self.session.parse_sess,
+                        sym::rustc_attrs,
+                        segment.ident.span,
+                        GateIssue::Language,
+                        msg,
+                    );
+                }
             }
         }
 
@@ -320,24 +332,15 @@ impl<'a> Resolver<'a> {
             }
             Res::NonMacroAttr(attr_kind) => {
                 if kind == MacroKind::Attr {
-                    let features = self.session.features_untracked();
                     if attr_kind == NonMacroAttrKind::Custom {
                         assert!(path.segments.len() == 1);
-                        let name = path.segments[0].ident.as_str();
-                        if name.starts_with("rustc_") {
-                            if !features.rustc_attrs {
-                                let msg = "unless otherwise specified, attributes with the prefix \
-                                           `rustc_` are reserved for internal compiler diagnostics";
-                                self.report_unknown_attribute(path.span, &name, msg,
-                                                              sym::rustc_attrs);
-                            }
-                        } else if !features.custom_attribute {
+                        if !features.custom_attribute {
                             let msg = format!("The attribute `{}` is currently unknown to the \
                                                compiler and may have meaning added to it in the \
                                                future", path);
                             self.report_unknown_attribute(
                                 path.span,
-                                &name,
+                                &path.segments[0].ident.as_str(),
                                 &msg,
                                 sym::custom_attribute,
                             );

src/libsyntax/ext/expand.rs

@@ -1504,9 +1504,7 @@ impl<'feat> ExpansionConfig<'feat> {
     }
 
     fn enable_custom_inner_attributes(&self) -> bool {
-        self.features.map_or(false, |features| {
-            features.custom_inner_attributes || features.custom_attribute || features.rustc_attrs
-        })
+        self.features.map_or(false, |features| features.custom_inner_attributes)
     }
 }
 

src/libsyntax/feature_gate.rs

@@ -1296,6 +1296,18 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
                                                     attribute is just used for rustc unit \
                                                     tests and will never be stable",
                                                     cfg_fn!(rustc_attrs))),
+    (sym::rustc_dump_env_program_clauses, Whitelisted, template!(Word), Gated(Stability::Unstable,
+                                                    sym::rustc_attrs,
+                                                    "the `#[rustc_dump_env_program_clauses]` \
+                                                    attribute is just used for rustc unit \
+                                                    tests and will never be stable",
+                                                    cfg_fn!(rustc_attrs))),
+    (sym::rustc_object_lifetime_default, Whitelisted, template!(Word), Gated(Stability::Unstable,
+                                                    sym::rustc_attrs,
+                                                    "the `#[rustc_object_lifetime_default]` \
+                                                    attribute is just used for rustc unit \
+                                                    tests and will never be stable",
+                                                    cfg_fn!(rustc_attrs))),
     (sym::rustc_test_marker, Normal, template!(Word), Gated(Stability::Unstable,
                                     sym::rustc_attrs,
                                     "the `#[rustc_test_marker]` attribute \
@@ -1357,6 +1369,26 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
                                                 "internal implementation detail",
                                                 cfg_fn!(rustc_attrs))),
 
+    (sym::rustc_allocator_nounwind, Whitelisted, template!(Word), Gated(Stability::Unstable,
+                                                sym::rustc_attrs,
+                                                "internal implementation detail",
+                                                cfg_fn!(rustc_attrs))),
+
+    (sym::rustc_doc_only_macro, Whitelisted, template!(Word), Gated(Stability::Unstable,
+                                                sym::rustc_attrs,
+                                                "internal implementation detail",
+                                                cfg_fn!(rustc_attrs))),
+
+    (sym::rustc_promotable, Whitelisted, template!(Word), Gated(Stability::Unstable,
+                                                sym::rustc_attrs,
+                                                "internal implementation detail",
+                                                cfg_fn!(rustc_attrs))),
+
+    (sym::rustc_allow_const_fn_ptr, Whitelisted, template!(Word), Gated(Stability::Unstable,
+                                                sym::rustc_attrs,
+                                                "internal implementation detail",
+                                                cfg_fn!(rustc_attrs))),
+
     (sym::rustc_dummy, Normal, template!(Word /* doesn't matter*/), Gated(Stability::Unstable,
                                          sym::rustc_attrs,
                                          "used by the test suite",
@@ -1643,6 +1675,14 @@ impl<'a> Context<'a> {
             }
             debug!("check_attribute: {:?} is builtin, {:?}, {:?}", attr.path, ty, gateage);
             return;
+        } else {
+            for segment in &attr.path.segments {
+                if segment.ident.as_str().starts_with("rustc") {
+                    let msg = "attributes starting with `rustc` are \
+                               reserved for use by the `rustc` compiler";
+                    gate_feature!(self, rustc_attrs, segment.ident.span, msg);
+                }
+            }
         }
         for &(n, ty) in self.plugin_attributes {
             if attr.path == n {
@@ -1653,19 +1693,13 @@ impl<'a> Context<'a> {
                 return;
             }
         }
-        if !attr::is_known(attr) {
-            if attr.name_or_empty().as_str().starts_with("rustc_") {
-                let msg = "unless otherwise specified, attributes with the prefix `rustc_` \
-                           are reserved for internal compiler diagnostics";
-                gate_feature!(self, rustc_attrs, attr.span, msg);
-            } else if !is_macro {
-                // Only run the custom attribute lint during regular feature gate
-                // checking. Macro gating runs before the plugin attributes are
-                // registered, so we skip this in that case.
-                let msg = format!("The attribute `{}` is currently unknown to the compiler and \
-                                   may have meaning added to it in the future", attr.path);
-                gate_feature!(self, custom_attribute, attr.span, &msg);
-            }
+        if !is_macro && !attr::is_known(attr) {
+            // Only run the custom attribute lint during regular feature gate
+            // checking. Macro gating runs before the plugin attributes are
+            // registered, so we skip this in that case.
+            let msg = format!("The attribute `{}` is currently unknown to the compiler and \
+                                may have meaning added to it in the future", attr.path);
+            gate_feature!(self, custom_attribute, attr.span, &msg);
         }
     }
 }

src/test/run-pass-fulldeps/issue-15778-pass.rs

@@ -2,12 +2,13 @@
 // ignore-stage1
 // compile-flags: -D crate-not-okay
 
-#![feature(plugin, rustc_attrs)]
+#![feature(plugin, custom_attribute, custom_inner_attributes, rustc_attrs)]
+
 #![plugin(lint_for_crate)]
 #![rustc_crate_okay]
 #![rustc_crate_blue]
 #![rustc_crate_red]
 #![rustc_crate_grey]
 #![rustc_crate_green]
 
-pub fn main() { }
+fn main() {}

src/test/ui/attributes/attrs-with-no-formal-in-generics-1.rs

@@ -6,10 +6,8 @@
 
 struct RefIntPair<'a, 'b>(&'a u32, &'b u32);
 
-impl<#[rustc_1] 'a, 'b, #[oops]> RefIntPair<'a, 'b> {
+impl<#[rustc_dummy] 'a, 'b, #[oops]> RefIntPair<'a, 'b> {
     //~^ ERROR trailing attribute after generic parameter
 }
 
-fn main() {
-
-}
+fn main() {}

src/test/ui/attributes/attrs-with-no-formal-in-generics-1.stderr

@@ -1,8 +1,8 @@
 error: trailing attribute after generic parameter
-  --> $DIR/attrs-with-no-formal-in-generics-1.rs:9:25
+  --> $DIR/attrs-with-no-formal-in-generics-1.rs:9:29
    |
-LL | impl<#[rustc_1] 'a, 'b, #[oops]> RefIntPair<'a, 'b> {
-   |                         ^^^^^^^ attributes must go before parameters
+LL | impl<#[rustc_dummy] 'a, 'b, #[oops]> RefIntPair<'a, 'b> {
+   |                             ^^^^^^^ attributes must go before parameters
 
 error: aborting due to previous error
 

src/test/ui/attributes/attrs-with-no-formal-in-generics-2.rs

@@ -6,7 +6,7 @@
 
 struct RefAny<'a, T>(&'a T);
 
-impl<#[rustc_1] 'a, #[rustc_2] T, #[oops]> RefAny<'a, T> {}
+impl<#[rustc_dummy] 'a, #[rustc_dummy] T, #[oops]> RefAny<'a, T> {}
 //~^ ERROR trailing attribute after generic parameter
 
 fn main() {}

src/test/ui/attributes/attrs-with-no-formal-in-generics-2.stderr

@@ -1,8 +1,8 @@
 error: trailing attribute after generic parameter
-  --> $DIR/attrs-with-no-formal-in-generics-2.rs:9:35
+  --> $DIR/attrs-with-no-formal-in-generics-2.rs:9:43
    |
-LL | impl<#[rustc_1] 'a, #[rustc_2] T, #[oops]> RefAny<'a, T> {}
-   |                                   ^^^^^^^ attributes must go before parameters
+LL | impl<#[rustc_dummy] 'a, #[rustc_dummy] T, #[oops]> RefAny<'a, T> {}
+   |                                           ^^^^^^^ attributes must go before parameters
 
 error: aborting due to previous error
 

src/test/ui/consts/min_const_fn/allow_const_fn_ptr_feature_gate.rs

@@ -5,7 +5,7 @@ const fn error(_: fn()) {}
 
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_allow_const_fn_ptr]
-//~^ ERROR unless otherwise specified, attributes with the prefix `rustc_` are reserved
+//~^ ERROR internal implementation detail
 const fn compiles(_: fn()) {}
 
 fn main() {}

src/test/ui/consts/min_const_fn/allow_const_fn_ptr_feature_gate.stderr

@@ -1,8 +1,8 @@
-error[E0658]: unless otherwise specified, attributes with the prefix `rustc_` are reserved for internal compiler diagnostics
-  --> $DIR/allow_const_fn_ptr_feature_gate.rs:7:3
+error[E0658]: internal implementation detail
+  --> $DIR/allow_const_fn_ptr_feature_gate.rs:7:1
    |
 LL | #[rustc_allow_const_fn_ptr]
-   |   ^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/29642
    = help: add #![feature(rustc_attrs)] to the crate attributes to enable

src/test/ui/feature-gates/feature-gate-rustc-attrs.rs

@@ -1,6 +1,23 @@
 // Test that `#[rustc_*]` attributes are gated by `rustc_attrs` feature gate.
 
-#[rustc_foo]
-//~^ ERROR unless otherwise specified, attributes with the prefix `rustc_` are reserved
+#![feature(decl_macro)]
 
+mod rustc { pub macro unknown() {} }
+mod unknown { pub macro rustc() {} }
+
+#[rustc::unknown]
+//~^ ERROR attributes starting with `rustc` are reserved for use by the `rustc` compiler
+//~| ERROR macro `rustc::unknown` may not be used in attributes
+fn f() {}
+
+#[unknown::rustc]
+//~^ ERROR attributes starting with `rustc` are reserved for use by the `rustc` compiler
+//~| ERROR macro `unknown::rustc` may not be used in attributes
+fn g() {}
+
+#[rustc_dummy]
+//~^ ERROR used by the test suite
+#[rustc_unknown]
+//~^ ERROR attributes starting with `rustc` are reserved for use by the `rustc` compiler
+//~| ERROR attribute `rustc_unknown` is currently unknown
 fn main() {}

src/test/ui/feature-gates/feature-gate-rustc-attrs.stderr

@@ -1,12 +1,60 @@
-error[E0658]: unless otherwise specified, attributes with the prefix `rustc_` are reserved for internal compiler diagnostics
-  --> $DIR/feature-gate-rustc-attrs.rs:3:3
+error[E0658]: attributes starting with `rustc` are reserved for use by the `rustc` compiler
+  --> $DIR/feature-gate-rustc-attrs.rs:8:3
    |
-LL | #[rustc_foo]
-   |   ^^^^^^^^^
+LL | #[rustc::unknown]
+   |   ^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/29642
    = help: add #![feature(rustc_attrs)] to the crate attributes to enable
 
-error: aborting due to previous error
+error: macro `rustc::unknown` may not be used in attributes
+  --> $DIR/feature-gate-rustc-attrs.rs:8:1
+   |
+LL | #[rustc::unknown]
+   | ^^^^^^^^^^^^^^^^^
+
+error[E0658]: attributes starting with `rustc` are reserved for use by the `rustc` compiler
+  --> $DIR/feature-gate-rustc-attrs.rs:13:12
+   |
+LL | #[unknown::rustc]
+   |            ^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(rustc_attrs)] to the crate attributes to enable
+
+error: macro `unknown::rustc` may not be used in attributes
+  --> $DIR/feature-gate-rustc-attrs.rs:13:1
+   |
+LL | #[unknown::rustc]
+   | ^^^^^^^^^^^^^^^^^
+
+error[E0658]: attributes starting with `rustc` are reserved for use by the `rustc` compiler
+  --> $DIR/feature-gate-rustc-attrs.rs:20:3
+   |
+LL | #[rustc_unknown]
+   |   ^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(rustc_attrs)] to the crate attributes to enable
+
+error[E0658]: The attribute `rustc_unknown` is currently unknown to the compiler and may have meaning added to it in the future
+  --> $DIR/feature-gate-rustc-attrs.rs:20:3
+   |
+LL | #[rustc_unknown]
+   |   ^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error[E0658]: used by the test suite
+  --> $DIR/feature-gate-rustc-attrs.rs:18:1
+   |
+LL | #[rustc_dummy]
+   | ^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(rustc_attrs)] to the crate attributes to enable
+
+error: aborting due to 7 previous errors
 
 For more information about this error, try `rustc --explain E0658`.