Auto merge of #40272 - jseyfried:fix_const_macro_invocations, r=petrochenkov

macros: fix const expression invocations

Fixes #40136.
r? @nrc

Author: bors

src/librustc/hir/map/def_collector.rs

@@ -26,7 +26,7 @@ pub struct DefCollector<'a> {
 pub struct MacroInvocationData {
     pub mark: Mark,
     pub def_index: DefIndex,
-    pub const_integer: bool,
+    pub const_expr: bool,
 }
 
 impl<'a> DefCollector<'a> {
@@ -65,10 +65,10 @@ impl<'a> DefCollector<'a> {
         self.parent_def = parent;
     }
 
-    pub fn visit_ast_const_integer(&mut self, expr: &Expr) {
+    pub fn visit_const_expr(&mut self, expr: &Expr) {
         match expr.node {
             // Find the node which will be used after lowering.
-            ExprKind::Paren(ref inner) => return self.visit_ast_const_integer(inner),
+            ExprKind::Paren(ref inner) => return self.visit_const_expr(inner),
             ExprKind::Mac(..) => return self.visit_macro_invoc(expr.id, true),
             // FIXME(eddyb) Closures should have separate
             // function definition IDs and expression IDs.
@@ -79,11 +79,11 @@ impl<'a> DefCollector<'a> {
         self.create_def(expr.id, DefPathData::Initializer);
     }
 
-    fn visit_macro_invoc(&mut self, id: NodeId, const_integer: bool) {
+    fn visit_macro_invoc(&mut self, id: NodeId, const_expr: bool) {
         if let Some(ref mut visit) = self.visit_macro_invoc {
             visit(MacroInvocationData {
                 mark: Mark::from_placeholder_id(id),
-                const_integer: const_integer,
+                const_expr: const_expr,
                 def_index: self.parent_def.unwrap(),
             })
         }
@@ -142,7 +142,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
                             }
 
                             if let Some(ref expr) = v.node.disr_expr {
-                                this.visit_ast_const_integer(expr);
+                                this.visit_const_expr(expr);
                             }
                         });
                     }
@@ -194,7 +194,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
         let def = self.create_def(ti.id, def_data);
         self.with_parent(def, |this| {
             if let TraitItemKind::Const(_, Some(ref expr)) = ti.node {
-                this.create_def(expr.id, DefPathData::Initializer);
+                this.visit_const_expr(expr);
             }
 
             visit::walk_trait_item(this, ti);
@@ -212,7 +212,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
         let def = self.create_def(ii.id, def_data);
         self.with_parent(def, |this| {
             if let ImplItemKind::Const(_, ref expr) = ii.node {
-                this.create_def(expr.id, DefPathData::Initializer);
+                this.visit_const_expr(expr);
             }
 
             visit::walk_impl_item(this, ii);
@@ -240,7 +240,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
 
         match expr.node {
             ExprKind::Mac(..) => return self.visit_macro_invoc(expr.id, false),
-            ExprKind::Repeat(_, ref count) => self.visit_ast_const_integer(count),
+            ExprKind::Repeat(_, ref count) => self.visit_const_expr(count),
             ExprKind::Closure(..) => {
                 let def = self.create_def(expr.id, DefPathData::ClosureExpr);
                 self.parent_def = Some(def);
@@ -255,11 +255,11 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
     fn visit_ty(&mut self, ty: &'a Ty) {
         match ty.node {
             TyKind::Mac(..) => return self.visit_macro_invoc(ty.id, false),
-            TyKind::Array(_, ref length) => self.visit_ast_const_integer(length),
+            TyKind::Array(_, ref length) => self.visit_const_expr(length),
             TyKind::ImplTrait(..) => {
                 self.create_def(ty.id, DefPathData::ImplTrait);
             }
-            TyKind::Typeof(ref expr) => self.visit_ast_const_integer(expr),
+            TyKind::Typeof(ref expr) => self.visit_const_expr(expr),
             _ => {}
         }
         visit::walk_ty(self, ty);

src/librustc_resolve/build_reduced_graph.rs

@@ -511,7 +511,7 @@ impl<'a> Resolver<'a> {
         let invocation = self.arenas.alloc_invocation_data(InvocationData {
             module: Cell::new(self.get_extern_crate_root(def_id.krate)),
             def_index: CRATE_DEF_INDEX,
-            const_integer: false,
+            const_expr: false,
             legacy_scope: Cell::new(LegacyScope::Empty),
             expansion: Cell::new(LegacyScope::Empty),
         });

src/librustc_resolve/macros.rs

@@ -40,9 +40,9 @@ use syntax_pos::{Span, DUMMY_SP};
 pub struct InvocationData<'a> {
     pub module: Cell<Module<'a>>,
     pub def_index: DefIndex,
-    // True if this expansion is in a `const_integer` position, for example `[u32; m!()]`.
-    // c.f. `DefCollector::visit_ast_const_integer`.
-    pub const_integer: bool,
+    // True if this expansion is in a `const_expr` position, for example `[u32; m!()]`.
+    // c.f. `DefCollector::visit_const_expr`.
+    pub const_expr: bool,
     // The scope in which the invocation path is resolved.
     pub legacy_scope: Cell<LegacyScope<'a>>,
     // The smallest scope that includes this invocation's expansion,
@@ -55,7 +55,7 @@ impl<'a> InvocationData<'a> {
         InvocationData {
             module: Cell::new(graph_root),
             def_index: CRATE_DEF_INDEX,
-            const_integer: false,
+            const_expr: false,
             legacy_scope: Cell::new(LegacyScope::Empty),
             expansion: Cell::new(LegacyScope::Empty),
         }
@@ -93,7 +93,7 @@ impl<'a> base::Resolver for Resolver<'a> {
         self.invocations.insert(mark, self.arenas.alloc_invocation_data(InvocationData {
             module: Cell::new(module),
             def_index: module.def_id().unwrap().index,
-            const_integer: false,
+            const_expr: false,
             legacy_scope: Cell::new(LegacyScope::Empty),
             expansion: Cell::new(LegacyScope::Empty),
         }));
@@ -517,13 +517,13 @@ impl<'a> Resolver<'a> {
 
     fn collect_def_ids(&mut self, invocation: &'a InvocationData<'a>, expansion: &Expansion) {
         let Resolver { ref mut invocations, arenas, graph_root, .. } = *self;
-        let InvocationData { def_index, const_integer, .. } = *invocation;
+        let InvocationData { def_index, const_expr, .. } = *invocation;
 
         let visit_macro_invoc = &mut |invoc: map::MacroInvocationData| {
             invocations.entry(invoc.mark).or_insert_with(|| {
                 arenas.alloc_invocation_data(InvocationData {
                     def_index: invoc.def_index,
-                    const_integer: invoc.const_integer,
+                    const_expr: invoc.const_expr,
                     module: Cell::new(graph_root),
                     expansion: Cell::new(LegacyScope::Empty),
                     legacy_scope: Cell::new(LegacyScope::Empty),
@@ -534,9 +534,9 @@ impl<'a> Resolver<'a> {
         let mut def_collector = DefCollector::new(&mut self.definitions);
         def_collector.visit_macro_invoc = Some(visit_macro_invoc);
         def_collector.with_parent(def_index, |def_collector| {
-            if const_integer {
+            if const_expr {
                 if let Expansion::Expr(ref expr) = *expansion {
-                    def_collector.visit_ast_const_integer(expr);
+                    def_collector.visit_const_expr(expr);
                 }
             }
             expansion.visit_with(def_collector)

src/test/run-pass/issue-40136.rs

@@ -0,0 +1,24 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(associated_consts)]
+
+macro_rules! m { () => { 0 } }
+
+trait T {
+   const C: i32 = m!();
+}
+
+struct S;
+impl S {
+    const C: i32 = m!();
+}
+
+fn main() {}