From 848b2d24096d646e475b2dae5fe8322af904e951 Mon Sep 17 00:00:00 2001
From: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>
Date: Sun, 30 Jun 2019 01:24:34 +0300
Subject: [PATCH] resolve: Reserve cfg/cfg_attr/derive only in attribute
sub-namespace
---
src/librustc_resolve/build_reduced_graph.rs | 16 +++++++++-----
src/librustc_resolve/macros.rs | 19 ++++++++++++-----
src/librustc_resolve/resolve_imports.rs | 21 ++++++-------------
.../feature-gate-const_panic.stderr | 16 +++++++-------
.../ui/proc-macro/reserved-macro-names.rs | 6 +++---
.../ui/proc-macro/reserved-macro-names.stderr | 6 +++---
6 files changed, 45 insertions(+), 39 deletions(-)
diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs
index 616728d541848..3921bd30df25c 100644
--- a/src/librustc_resolve/build_reduced_graph.rs
+++ b/src/librustc_resolve/build_reduced_graph.rs
@@ -770,19 +770,25 @@ impl<'a> Resolver<'a> {
}
pub fn get_macro(&mut self, res: Res) -> Lrc<SyntaxExtension> {
+ self.opt_get_macro(res).expect("expected `DefKind::Macro` or `Res::NonMacroAttr`")
+ }
+
+ crate fn opt_get_macro(&mut self, res: Res) -> Option<Lrc<SyntaxExtension>> {
let def_id = match res {
+ Res::Def(DefKind::Macro(MacroKind::ProcMacroStub), _) =>
+ return Some(self.non_macro_attr(true)), // some dummy extension
Res::Def(DefKind::Macro(..), def_id) => def_id,
Res::NonMacroAttr(attr_kind) =>
- return self.non_macro_attr(attr_kind == NonMacroAttrKind::Tool),
- _ => panic!("expected `DefKind::Macro` or `Res::NonMacroAttr`"),
+ return Some(self.non_macro_attr(attr_kind == NonMacroAttrKind::Tool)),
+ _ => return None,
};
if let Some(ext) = self.macro_map.get(&def_id) {
- return ext.clone();
+ return Some(ext.clone());
}
let macro_def = match self.cstore.load_macro_untracked(def_id, &self.session) {
LoadedMacro::MacroDef(macro_def) => macro_def,
- LoadedMacro::ProcMacro(ext) => return ext,
+ LoadedMacro::ProcMacro(ext) => return Some(ext),
};
let ext = Lrc::new(macro_rules::compile(&self.session.parse_sess,
@@ -790,7 +796,7 @@ impl<'a> Resolver<'a> {
¯o_def,
self.cstore.crate_edition_untracked(def_id.krate)));
self.macro_map.insert(def_id, ext.clone());
- ext
+ Some(ext)
}
/// Ensures that the reduced graph rooted at the given external module
diff --git a/src/librustc_resolve/macros.rs b/src/librustc_resolve/macros.rs
index 6a8c46eaa40fb..7b509191d589f 100644
--- a/src/librustc_resolve/macros.rs
+++ b/src/librustc_resolve/macros.rs
@@ -1106,6 +1106,17 @@ impl<'a> Resolver<'a> {
});
}
+ crate fn check_reserved_macro_name(&self, ident: Ident, macro_kind: Option<MacroKind>) {
+ // Reserve some names that are not quite covered by the general check
+ // performed on `Resolver::builtin_attrs`.
+ if (macro_kind.is_some() && sub_namespace_match(macro_kind, Some(MacroKind::Attr))) &&
+ (ident.name == sym::cfg || ident.name == sym::cfg_attr || ident.name == sym::derive) {
+ self.session.span_err(
+ ident.span, &format!("name `{}` is reserved in attribute namespace", ident)
+ );
+ }
+ }
+
pub fn define_macro(&mut self,
item: &ast::Item,
expansion: Mark,
@@ -1117,13 +1128,14 @@ impl<'a> Resolver<'a> {
let ext = Lrc::new(macro_rules::compile(&self.session.parse_sess,
&self.session.features_untracked(),
item, self.session.edition()));
+ let macro_kind = ext.macro_kind();
+ let res = Res::Def(DefKind::Macro(macro_kind), def_id);
self.macro_map.insert(def_id, ext);
let def = match item.node { ast::ItemKind::MacroDef(ref def) => def, _ => unreachable!() };
if def.legacy {
let ident = ident.modern();
self.macro_names.insert(ident);
- let res = Res::Def(DefKind::Macro(MacroKind::Bang), def_id);
let is_macro_export = attr::contains_name(&item.attrs, sym::macro_export);
let vis = if is_macro_export {
ty::Visibility::Public
@@ -1142,14 +1154,11 @@ impl<'a> Resolver<'a> {
self.define(module, ident, MacroNS,
(res, vis, item.span, expansion, IsMacroExport));
} else {
- if !attr::contains_name(&item.attrs, sym::rustc_builtin_macro) {
- self.check_reserved_macro_name(ident, MacroNS);
- }
+ self.check_reserved_macro_name(ident, Some(macro_kind));
self.unused_macros.insert(def_id);
}
} else {
let module = self.current_module;
- let res = Res::Def(DefKind::Macro(MacroKind::Bang), def_id);
let vis = self.resolve_visibility(&item.vis);
if vis != ty::Visibility::Public {
self.unused_macros.insert(def_id);
diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs
index 404d728d8808c..3b20647d0bf9c 100644
--- a/src/librustc_resolve/resolve_imports.rs
+++ b/src/librustc_resolve/resolve_imports.rs
@@ -29,7 +29,7 @@ use rustc::{bug, span_bug};
use syntax::ast::{self, Ident, Name, NodeId, CRATE_NODE_ID};
use syntax::ext::base::Determinacy::{self, Determined, Undetermined};
use syntax::ext::hygiene::Mark;
-use syntax::symbol::{kw, sym};
+use syntax::symbol::kw;
use syntax::util::lev_distance::find_best_match_for_name;
use syntax::{struct_span_err, unwrap_or};
use syntax_pos::{MultiSpan, Span};
@@ -492,17 +492,6 @@ impl<'a> Resolver<'a> {
})
}
- crate fn check_reserved_macro_name(&self, ident: Ident, ns: Namespace) {
- // Reserve some names that are not quite covered by the general check
- // performed on `Resolver::builtin_attrs`.
- if ns == MacroNS &&
- (ident.name == sym::cfg || ident.name == sym::cfg_attr ||
- ident.name == sym::derive) {
- self.session.span_err(ident.span,
- &format!("name `{}` is reserved in macro namespace", ident));
- }
- }
-
// Define the name or return the existing binding if there is a collision.
pub fn try_define(&mut self,
module: Module<'a>,
@@ -510,17 +499,19 @@ impl<'a> Resolver<'a> {
ns: Namespace,
binding: &'a NameBinding<'a>)
-> Result<(), &'a NameBinding<'a>> {
- self.check_reserved_macro_name(ident, ns);
+ let res = binding.res();
+ let macro_kind = self.opt_get_macro(res).map(|ext| ext.macro_kind());
+ self.check_reserved_macro_name(ident, macro_kind);
self.set_binding_parent_module(binding, module);
self.update_resolution(module, ident, ns, |this, resolution| {
if let Some(old_binding) = resolution.binding {
- if binding.res() == Res::Err {
+ if res == Res::Err {
// Do not override real bindings with `Res::Err`s from error recovery.
return Ok(());
}
match (old_binding.is_glob_import(), binding.is_glob_import()) {
(true, true) => {
- if binding.res() != old_binding.res() {
+ if res != old_binding.res() {
resolution.binding = Some(this.ambiguity(AmbiguityKind::GlobVsGlob,
old_binding, binding));
} else if !old_binding.vis.is_at_least(binding.vis, &*this) {
diff --git a/src/test/ui/consts/const-eval/feature-gate-const_panic.stderr b/src/test/ui/consts/const-eval/feature-gate-const_panic.stderr
index 5d3e88e4e58c2..bf45b9d9021bc 100644
--- a/src/test/ui/consts/const-eval/feature-gate-const_panic.stderr
+++ b/src/test/ui/consts/const-eval/feature-gate-const_panic.stderr
@@ -1,17 +1,17 @@
error[E0658]: panicking in constants is unstable
- --> $DIR/feature-gate-const_panic.rs:3:15
+ --> $DIR/feature-gate-const_panic.rs:6:15
|
-LL | const Z: () = panic!("cheese");
- | ^^^^^^^^^^^^^^^^
+LL | const Y: () = unreachable!();
+ | ^^^^^^^^^^^^^^
|
= note: for more information, see https://github.com/rust-lang/rust/issues/51999
= help: add #![feature(const_panic)] to the crate attributes to enable
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error[E0658]: panicking in constants is unstable
- --> $DIR/feature-gate-const_panic.rs:9:15
+ --> $DIR/feature-gate-const_panic.rs:3:15
|
-LL | const X: () = unimplemented!();
+LL | const Z: () = panic!("cheese");
| ^^^^^^^^^^^^^^^^
|
= note: for more information, see https://github.com/rust-lang/rust/issues/51999
@@ -19,10 +19,10 @@ LL | const X: () = unimplemented!();
= note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
error[E0658]: panicking in constants is unstable
- --> $DIR/feature-gate-const_panic.rs:6:15
+ --> $DIR/feature-gate-const_panic.rs:9:15
|
-LL | const Y: () = unreachable!();
- | ^^^^^^^^^^^^^^
+LL | const X: () = unimplemented!();
+ | ^^^^^^^^^^^^^^^^
|
= note: for more information, see https://github.com/rust-lang/rust/issues/51999
= help: add #![feature(const_panic)] to the crate attributes to enable
diff --git a/src/test/ui/proc-macro/reserved-macro-names.rs b/src/test/ui/proc-macro/reserved-macro-names.rs
index 7c66af172fd5e..9f56eccb7a61c 100644
--- a/src/test/ui/proc-macro/reserved-macro-names.rs
+++ b/src/test/ui/proc-macro/reserved-macro-names.rs
@@ -8,18 +8,18 @@ use proc_macro::*;
#[proc_macro_attribute]
pub fn cfg(_: TokenStream, input: TokenStream) -> TokenStream {
- //~^ ERROR name `cfg` is reserved in macro namespace
+ //~^ ERROR name `cfg` is reserved in attribute namespace
input
}
#[proc_macro_attribute]
pub fn cfg_attr(_: TokenStream, input: TokenStream) -> TokenStream {
- //~^ ERROR name `cfg_attr` is reserved in macro namespace
+ //~^ ERROR name `cfg_attr` is reserved in attribute namespace
input
}
#[proc_macro_attribute]
pub fn derive(_: TokenStream, input: TokenStream) -> TokenStream {
- //~^ ERROR name `derive` is reserved in macro namespace
+ //~^ ERROR name `derive` is reserved in attribute namespace
input
}
diff --git a/src/test/ui/proc-macro/reserved-macro-names.stderr b/src/test/ui/proc-macro/reserved-macro-names.stderr
index 5ebe62a4969bb..f871e43ce51df 100644
--- a/src/test/ui/proc-macro/reserved-macro-names.stderr
+++ b/src/test/ui/proc-macro/reserved-macro-names.stderr
@@ -1,16 +1,16 @@
-error: name `cfg` is reserved in macro namespace
+error: name `cfg` is reserved in attribute namespace
--> $DIR/reserved-macro-names.rs:10:8
|
LL | pub fn cfg(_: TokenStream, input: TokenStream) -> TokenStream {
| ^^^
-error: name `cfg_attr` is reserved in macro namespace
+error: name `cfg_attr` is reserved in attribute namespace
--> $DIR/reserved-macro-names.rs:16:8
|
LL | pub fn cfg_attr(_: TokenStream, input: TokenStream) -> TokenStream {
| ^^^^^^^^
-error: name `derive` is reserved in macro namespace
+error: name `derive` is reserved in attribute namespace
--> $DIR/reserved-macro-names.rs:22:8
|
LL | pub fn derive(_: TokenStream, input: TokenStream) -> TokenStream {