syntax: Remove SyntaxExtension::DeclMacro

It's a less powerful duplicate of `SyntaxExtension::NormalTT`

src/librustc_plugin/registry.rs

@@ -6,6 +6,7 @@ use rustc::util::nodemap::FxHashMap;
 
 use syntax::ext::base::{SyntaxExtension, NamedSyntaxExtension, NormalTT};
 use syntax::ext::base::MacroExpanderFn;
+use syntax::ext::hygiene::Transparency;
 use syntax::symbol::{Symbol, sym};
 use syntax::ast;
 use syntax::feature_gate::AttributeType;
@@ -84,33 +85,14 @@ impl<'a> Registry<'a> {
     /// Register a syntax extension of any kind.
     ///
     /// This is the most general hook into `libsyntax`'s expansion behavior.
-    pub fn register_syntax_extension(&mut self, name: ast::Name, extension: SyntaxExtension) {
+    pub fn register_syntax_extension(&mut self, name: ast::Name, mut extension: SyntaxExtension) {
         if name == sym::macro_rules {
             panic!("user-defined macros may not be named `macro_rules`");
         }
-        self.syntax_exts.push((name, match extension {
-            NormalTT {
-                expander,
-                def_info: _,
-                allow_internal_unstable,
-                allow_internal_unsafe,
-                local_inner_macros,
-                unstable_feature,
-                edition,
-            } => {
-                let nid = ast::CRATE_NODE_ID;
-                NormalTT {
-                    expander,
-                    def_info: Some((nid, self.krate_span)),
-                    allow_internal_unstable,
-                    allow_internal_unsafe,
-                    local_inner_macros,
-                    unstable_feature,
-                    edition,
-                }
-            }
-            _ => extension,
-        }));
+        if let NormalTT { def_info: ref mut def_info @ None, .. } = extension {
+            *def_info = Some((ast::CRATE_NODE_ID, self.krate_span));
+        }
+        self.syntax_exts.push((name, extension));
     }
 
     /// Register a macro of the usual kind.
@@ -122,6 +104,7 @@ impl<'a> Registry<'a> {
         self.register_syntax_extension(Symbol::intern(name), NormalTT {
             expander: Box::new(expander),
             def_info: None,
+            transparency: Transparency::SemiTransparent,
             allow_internal_unstable: None,
             allow_internal_unsafe: false,
             local_inner_macros: false,

src/librustc_resolve/macros.rs

@@ -242,8 +242,7 @@ impl<'a> base::Resolver for Resolver<'a> {
     fn check_unused_macros(&self) {
         for did in self.unused_macros.iter() {
             let id_span = match *self.macro_map[did] {
-                SyntaxExtension::NormalTT { def_info, .. } |
-                SyntaxExtension::DeclMacro { def_info, .. } => def_info,
+                SyntaxExtension::NormalTT { def_info, .. } => def_info,
                 _ => None,
             };
             if let Some((id, span)) = id_span {

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -433,7 +433,7 @@ fn macro_resolve(cx: &DocContext<'_>, path_str: &str) -> Option<Res> {
             if let Res::Def(DefKind::Macro(MacroKind::ProcMacroStub), _) = res {
                 // skip proc-macro stubs, they'll cause `get_macro` to crash
             } else {
-                if let SyntaxExtension::DeclMacro { .. } = *resolver.get_macro(res) {
+                if let SyntaxExtension::NormalTT { .. } = *resolver.get_macro(res) {
                     return Some(res.map_id(|_| panic!("unexpected id")));
                 }
             }

src/libsyntax/ext/base.rs

@@ -579,6 +579,7 @@ pub enum SyntaxExtension {
     NormalTT {
         expander: Box<dyn TTMacroExpander + sync::Sync + sync::Send>,
         def_info: Option<(ast::NodeId, Span)>,
+        transparency: Transparency,
         /// Whether the contents of the macro can
         /// directly use `#[unstable]` things.
         ///
@@ -605,21 +606,12 @@ pub enum SyntaxExtension {
 
     /// An attribute-like procedural macro that derives a builtin trait.
     BuiltinDerive(Box<dyn MultiItemModifier + sync::Sync + sync::Send>),
-
-    /// A declarative macro, e.g., `macro m() {}`.
-    DeclMacro {
-        expander: Box<dyn TTMacroExpander + sync::Sync + sync::Send>,
-        def_info: Option<(ast::NodeId, Span)>,
-        is_transparent: bool,
-        edition: Edition,
-    }
 }
 
 impl SyntaxExtension {
     /// Returns which kind of macro calls this syntax extension.
     pub fn kind(&self) -> MacroKind {
         match *self {
-            SyntaxExtension::DeclMacro { .. } |
             SyntaxExtension::NormalTT { .. } |
             SyntaxExtension::ProcMacro { .. } =>
                 MacroKind::Bang,
@@ -635,19 +627,19 @@ impl SyntaxExtension {
 
     pub fn default_transparency(&self) -> Transparency {
         match *self {
+            SyntaxExtension::NormalTT { transparency, .. } => transparency,
             SyntaxExtension::ProcMacro { .. } |
             SyntaxExtension::AttrProcMacro(..) |
             SyntaxExtension::ProcMacroDerive(..) |
-            SyntaxExtension::DeclMacro { is_transparent: false, .. } => Transparency::Opaque,
-            SyntaxExtension::DeclMacro { is_transparent: true, .. } => Transparency::Transparent,
-            _ => Transparency::SemiTransparent,
+            SyntaxExtension::NonMacroAttr { .. } => Transparency::Opaque,
+            SyntaxExtension::MultiModifier(..) |
+            SyntaxExtension::BuiltinDerive(..) => Transparency::SemiTransparent,
         }
     }
 
     pub fn edition(&self, default_edition: Edition) -> Edition {
         match *self {
             SyntaxExtension::NormalTT { edition, .. } |
-            SyntaxExtension::DeclMacro { edition, .. } |
             SyntaxExtension::ProcMacro { edition, .. } |
             SyntaxExtension::AttrProcMacro(.., edition) |
             SyntaxExtension::ProcMacroDerive(.., edition) => edition,

src/libsyntax/ext/expand.rs

@@ -747,16 +747,6 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
         };
 
         let opt_expanded = match *ext {
-            DeclMacro { ref expander, def_info, edition, .. } => {
-                if let Err(dummy_span) = validate_and_set_expn_info(self, def_info.map(|(_, s)| s),
-                                                                    None, false, false, None,
-                                                                    edition) {
-                    dummy_span
-                } else {
-                    kind.make_from(expander.expand(self.cx, span, mac.node.stream(), None))
-                }
-            }
-
             NormalTT {
                 ref expander,
                 def_info,
@@ -765,6 +755,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 local_inner_macros,
                 unstable_feature,
                 edition,
+                ..
             } => {
                 if let Err(dummy_span) = validate_and_set_expn_info(self, def_info.map(|(_, s)| s),
                                                                     allow_internal_unstable.clone(),

src/libsyntax/ext/tt/macro_rules.rs

@@ -3,6 +3,7 @@ use crate::edition::Edition;
 use crate::ext::base::{DummyResult, ExtCtxt, MacResult, SyntaxExtension};
 use crate::ext::base::{NormalTT, TTMacroExpander};
 use crate::ext::expand::{AstFragment, AstFragmentKind};
+use crate::ext::hygiene::Transparency;
 use crate::ext::tt::macro_parser::{Success, Error, Failure};
 use crate::ext::tt::macro_parser::{MatchedSeq, MatchedNonterminal};
 use crate::ext::tt::macro_parser::{parse, parse_failure_msg};
@@ -374,65 +375,65 @@ pub fn compile(
         valid,
     });
 
-    if body.legacy {
-        let allow_internal_unstable = attr::find_by_name(&def.attrs, sym::allow_internal_unstable)
-            .map(|attr| attr
-                .meta_item_list()
-                .map(|list| list.iter()
-                    .filter_map(|it| {
-                        let name = it.ident().map(|ident| ident.name);
-                        if name.is_none() {
-                            sess.span_diagnostic.span_err(it.span(),
-                                "allow internal unstable expects feature names")
-                        }
-                        name
-                    })
-                    .collect::<Vec<Symbol>>().into()
-                )
-                .unwrap_or_else(|| {
-                    sess.span_diagnostic.span_warn(
-                        attr.span, "allow_internal_unstable expects list of feature names. In the \
-                        future this will become a hard error. Please use `allow_internal_unstable(\
-                        foo, bar)` to only allow the `foo` and `bar` features",
-                    );
-                    vec![sym::allow_internal_unstable_backcompat_hack].into()
+    let transparency = if attr::contains_name(&def.attrs, sym::rustc_transparent_macro) {
+        Transparency::Transparent
+    } else if body.legacy {
+        Transparency::SemiTransparent
+    } else {
+        Transparency::Opaque
+    };
+
+    let allow_internal_unstable = attr::find_by_name(&def.attrs, sym::allow_internal_unstable)
+        .map(|attr| attr
+            .meta_item_list()
+            .map(|list| list.iter()
+                .filter_map(|it| {
+                    let name = it.ident().map(|ident| ident.name);
+                    if name.is_none() {
+                        sess.span_diagnostic.span_err(it.span(),
+                            "allow internal unstable expects feature names")
+                    }
+                    name
                 })
-            );
-        let allow_internal_unsafe = attr::contains_name(&def.attrs, sym::allow_internal_unsafe);
-        let mut local_inner_macros = false;
-        if let Some(macro_export) = attr::find_by_name(&def.attrs, sym::macro_export) {
-            if let Some(l) = macro_export.meta_item_list() {
-                local_inner_macros = attr::list_contains_name(&l, sym::local_inner_macros);
-            }
-        }
+                .collect::<Vec<Symbol>>().into()
+            )
+            .unwrap_or_else(|| {
+                sess.span_diagnostic.span_warn(
+                    attr.span, "allow_internal_unstable expects list of feature names. In the \
+                    future this will become a hard error. Please use `allow_internal_unstable(\
+                    foo, bar)` to only allow the `foo` and `bar` features",
+                );
+                vec![sym::allow_internal_unstable_backcompat_hack].into()
+            })
+        );
 
-        let unstable_feature = attr::find_stability(&sess,
-                                                    &def.attrs, def.span).and_then(|stability| {
-            if let attr::StabilityLevel::Unstable { issue, .. } = stability.level {
-                Some((stability.feature, issue))
-            } else {
-                None
-            }
-        });
-
-        NormalTT {
-            expander,
-            def_info: Some((def.id, def.span)),
-            allow_internal_unstable,
-            allow_internal_unsafe,
-            local_inner_macros,
-            unstable_feature,
-            edition,
+    let allow_internal_unsafe = attr::contains_name(&def.attrs, sym::allow_internal_unsafe);
+
+    let mut local_inner_macros = false;
+    if let Some(macro_export) = attr::find_by_name(&def.attrs, sym::macro_export) {
+        if let Some(l) = macro_export.meta_item_list() {
+            local_inner_macros = attr::list_contains_name(&l, sym::local_inner_macros);
         }
-    } else {
-        let is_transparent = attr::contains_name(&def.attrs, sym::rustc_transparent_macro);
+    }
 
-        SyntaxExtension::DeclMacro {
-            expander,
-            def_info: Some((def.id, def.span)),
-            is_transparent,
-            edition,
+    let unstable_feature = attr::find_stability(&sess,
+                                                &def.attrs, def.span).and_then(|stability| {
+        if let attr::StabilityLevel::Unstable { issue, .. } = stability.level {
+            Some((stability.feature, issue))
+        } else {
+            None
         }
+    });
+
+    NormalTT {
+        expander,
+        def_info: Some((def.id, def.span)),
+        transparency,
+        allow_internal_unstable,
+        allow_internal_unsafe,
+        local_inner_macros,
+        unstable_feature,
+        edition,
     }
 }
 

src/libsyntax_ext/lib.rs

@@ -42,6 +42,7 @@ pub mod proc_macro_impl;
 use rustc_data_structures::sync::Lrc;
 use syntax::ast;
 use syntax::ext::base::{MacroExpanderFn, NormalTT, NamedSyntaxExtension, MultiModifier};
+use syntax::ext::hygiene::Transparency;
 use syntax::edition::Edition;
 use syntax::symbol::{sym, Symbol};
 
@@ -59,6 +60,7 @@ pub fn register_builtins(resolver: &mut dyn syntax::ext::base::Resolver,
                      NormalTT {
                         expander: Box::new($f as MacroExpanderFn),
                         def_info: None,
+                        transparency: Transparency::SemiTransparent,
                         allow_internal_unstable: None,
                         allow_internal_unsafe: false,
                         local_inner_macros: false,
@@ -102,6 +104,7 @@ pub fn register_builtins(resolver: &mut dyn syntax::ext::base::Resolver,
              NormalTT {
                 expander: Box::new(format::expand_format_args),
                 def_info: None,
+                transparency: Transparency::SemiTransparent,
                 allow_internal_unstable: Some(vec![sym::fmt_internals].into()),
                 allow_internal_unsafe: false,
                 local_inner_macros: false,
@@ -112,6 +115,7 @@ pub fn register_builtins(resolver: &mut dyn syntax::ext::base::Resolver,
              NormalTT {
                  expander: Box::new(format::expand_format_args_nl),
                  def_info: None,
+                 transparency: Transparency::SemiTransparent,
                  allow_internal_unstable: Some(vec![sym::fmt_internals].into()),
                  allow_internal_unsafe: false,
                  local_inner_macros: false,

src/test/run-pass-fulldeps/auxiliary/plugin-args.rs

@@ -13,6 +13,7 @@ use syntax::ast;
 use syntax::ext::hygiene;
 use syntax::ext::build::AstBuilder;
 use syntax::ext::base::{TTMacroExpander, ExtCtxt, MacResult, MacEager, NormalTT};
+use syntax::ext::hygiene::Transparency;
 use syntax::print::pprust;
 use syntax::ptr::P;
 use syntax::symbol::Symbol;
@@ -43,6 +44,7 @@ pub fn plugin_registrar(reg: &mut Registry) {
         NormalTT {
             expander: Box::new(Expander { args: args, }),
             def_info: None,
+            transparency: Transparency::SemiTransparent,
             allow_internal_unstable: None,
             allow_internal_unsafe: false,
             local_inner_macros: false,

src/test/ui/macros/nonterminal-matching.stderr

@@ -1,6 +1,9 @@
 error: no rules expected the token `enum E { }`
   --> $DIR/nonterminal-matching.rs:19:10
    |
+LL |     macro n(a $nt_item b) {
+   |     --------------------- when calling this macro
+...
 LL |     n!(a $nt_item b);
    |          ^^^^^^^^ no rules expected this token in macro call
 ...