Rollup merge of #57915 - petrochenkov:notto-disu, r=zackmdavis

Pretty print `$crate` as `crate` or `crate_name` in more cases

So, people do parse output of `--pretty=expanded` (sigh), so covering only the legacy proc-macro case (like it was done in https://github.com/rust-lang/rust/pull/57155) is not enough.

This PRs resolves all `$crate`s produced by macros, so they are all printed in the parseable form `$crate::foo` -> `crate::foo` or `crate_name::foo`.

Fixes https://github.com/rust-lang/rust/issues/38016#issuecomment-455851334
Fixes https://github.com/rust-lang/rust/pull/57155#issuecomment-455807195

2 files changed, 5 insertions, 18 deletions

diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 2793754e103..09e7e57f78c 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -14,7 +14,6 @@ use parse::token;
 use ptr::P;
 use smallvec::SmallVec;
 use symbol::{keywords, Ident, Symbol};
-use visit::Visitor;
 use ThinVec;
 
 use rustc_data_structures::fx::FxHashMap;
@@ -136,17 +135,6 @@ impl Annotatable {
             _ => false,
         }
     }
-
-    pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) {
-        match self {
-            Annotatable::Item(item) => visitor.visit_item(item),
-            Annotatable::TraitItem(trait_item) => visitor.visit_trait_item(trait_item),
-            Annotatable::ImplItem(impl_item) => visitor.visit_impl_item(impl_item),
-            Annotatable::ForeignItem(foreign_item) => visitor.visit_foreign_item(foreign_item),
-            Annotatable::Stmt(stmt) => visitor.visit_stmt(stmt),
-            Annotatable::Expr(expr) => visitor.visit_expr(expr),
-        }
-    }
 }
 
 // A more flexible ItemDecorator.
@@ -742,7 +730,7 @@ pub trait Resolver {
     fn next_node_id(&mut self) -> ast::NodeId;
     fn get_module_scope(&mut self, id: ast::NodeId) -> Mark;
 
-    fn resolve_dollar_crates(&mut self, annotatable: &Annotatable);
+    fn resolve_dollar_crates(&mut self, fragment: &AstFragment);
     fn visit_ast_fragment_with_placeholders(&mut self, mark: Mark, fragment: &AstFragment,
                                             derives: &[Mark]);
     fn add_builtin(&mut self, ident: ast::Ident, ext: Lrc<SyntaxExtension>);
@@ -776,7 +764,7 @@ impl Resolver for DummyResolver {
     fn next_node_id(&mut self) -> ast::NodeId { ast::DUMMY_NODE_ID }
     fn get_module_scope(&mut self, _id: ast::NodeId) -> Mark { Mark::root() }
 
-    fn resolve_dollar_crates(&mut self, _annotatable: &Annotatable) {}
+    fn resolve_dollar_crates(&mut self, _fragment: &AstFragment) {}
     fn visit_ast_fragment_with_placeholders(&mut self, _invoc: Mark, _fragment: &AstFragment,
                                             _derives: &[Mark]) {}
     fn add_builtin(&mut self, _ident: ast::Ident, _ext: Lrc<SyntaxExtension>) {}
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index d1f7b4df9be..1b4b44270ad 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -443,6 +443,9 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
     /// prepares data for resolving paths of macro invocations.
     fn collect_invocations(&mut self, fragment: AstFragment, derives: &[Mark])
                            -> (AstFragment, Vec<Invocation>) {
+        // Resolve `$crate`s in the fragment for pretty-printing.
+        self.cx.resolver.resolve_dollar_crates(&fragment);
+
         let (fragment_with_placeholders, invocations) = {
             let mut collector = InvocationCollector {
                 cfg: StripUnconfigured {
@@ -574,8 +577,6 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 Some(invoc.fragment_kind.expect_from_annotatables(items))
             }
             AttrProcMacro(ref mac, ..) => {
-                // Resolve `$crate`s in case we have to go though stringification.
-                self.cx.resolver.resolve_dollar_crates(&item);
                 self.gate_proc_macro_attr_item(attr.span, &item);
                 let item_tok = TokenTree::Token(DUMMY_SP, Token::interpolated(match item {
                     Annotatable::Item(item) => token::NtItem(item),
@@ -917,8 +918,6 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
 
         match *ext {
             ProcMacroDerive(ref ext, ..) => {
-                // Resolve `$crate`s in case we have to go though stringification.
-                self.cx.resolver.resolve_dollar_crates(&item);
                 invoc.expansion_data.mark.set_expn_info(expn_info);
                 let span = span.with_ctxt(self.cx.backtrace());
                 let dummy = ast::MetaItem { // FIXME(jseyfried) avoid this