Look up macro names as well when suggesting replacements for function resolve errors

fixes #5780

src/libsyntax/ext/base.rs

@@ -27,7 +27,7 @@ use util::small_vector::SmallVector;
 use ext::mtwt;
 use fold::Folder;
 
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 use std::rc::Rc;
 use std::default::Default;
 
@@ -856,7 +856,10 @@ pub fn get_exprs_from_tts(cx: &mut ExtCtxt,
 ///
 /// This environment maps Names to SyntaxExtensions.
 pub struct SyntaxEnv {
-    chain: Vec<MapChainFrame> ,
+    chain: Vec<MapChainFrame>,
+    /// All bang-style macro/extension names
+    /// encountered so far; to be used for diagnostics in resolve
+    pub names: HashSet<Name>,
 }
 
 // impl question: how to implement it? Initially, the
@@ -876,7 +879,7 @@ struct MapChainFrame {
 
 impl SyntaxEnv {
     fn new() -> SyntaxEnv {
-        let mut map = SyntaxEnv { chain: Vec::new() };
+        let mut map = SyntaxEnv { chain: Vec::new() , names: HashSet::new()};
         map.push_frame();
         map
     }
@@ -913,6 +916,9 @@ impl SyntaxEnv {
     }
 
     pub fn insert(&mut self, k: Name, v: SyntaxExtension) {
+        if let NormalTT(..) = v {
+            self.names.insert(k);
+        }
         self.find_escape_frame().map.insert(k, Rc::new(v));
     }
 

src/libsyntax/ext/expand.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 use ast::{Block, Crate, DeclLocal, ExprMac, PatMac};
-use ast::{Local, Ident, Mac_};
+use ast::{Local, Ident, Mac_, Name};
 use ast::{ItemMac, MacStmtWithSemicolon, Mrk, Stmt, StmtDecl, StmtMac};
 use ast::{StmtExpr, StmtSemi};
 use ast::TokenTree;
@@ -32,6 +32,8 @@ use visit;
 use visit::Visitor;
 use std_inject;
 
+use std::collections::HashSet;
+
 
 pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
     let expr_span = e.span;
@@ -1261,7 +1263,7 @@ pub fn expand_crate<'feat>(parse_sess: &parse::ParseSess,
                            imported_macros: Vec<ast::MacroDef>,
                            user_exts: Vec<NamedSyntaxExtension>,
                            feature_gated_cfgs: &mut Vec<GatedCfg>,
-                           c: Crate) -> Crate {
+                           c: Crate) -> (Crate, HashSet<Name>) {
     let mut cx = ExtCtxt::new(parse_sess, c.config.clone(), cfg,
                               feature_gated_cfgs);
     if std_inject::no_core(&c) {
@@ -1271,21 +1273,23 @@ pub fn expand_crate<'feat>(parse_sess: &parse::ParseSess,
     } else {
         cx.crate_root = Some("std");
     }
+    let ret = {
+        let mut expander = MacroExpander::new(&mut cx);
 
-    let mut expander = MacroExpander::new(&mut cx);
+        for def in imported_macros {
+            expander.cx.insert_macro(def);
+        }
 
-    for def in imported_macros {
-        expander.cx.insert_macro(def);
-    }
+        for (name, extension) in user_exts {
+            expander.cx.syntax_env.insert(name, extension);
+        }
 
-    for (name, extension) in user_exts {
-        expander.cx.syntax_env.insert(name, extension);
-    }
-
-    let mut ret = expander.fold_crate(c);
-    ret.exported_macros = expander.cx.exported_macros.clone();
-    parse_sess.span_diagnostic.handler().abort_if_errors();
-    return ret;
+        let mut ret = expander.fold_crate(c);
+        ret.exported_macros = expander.cx.exported_macros.clone();
+        parse_sess.span_diagnostic.handler().abort_if_errors();
+        ret
+    };
+    return (ret, cx.syntax_env.names);
 }
 
 // HYGIENIC CONTEXT EXTENSION:
@@ -1480,7 +1484,7 @@ mod tests {
         let ps = parse::ParseSess::new();
         let crate_ast = panictry!(string_to_parser(&ps, crate_str).parse_crate_mod());
         // the cfg argument actually does matter, here...
-        expand_crate(&ps,test_ecfg(),vec!(),vec!(), &mut vec![], crate_ast)
+        expand_crate(&ps,test_ecfg(),vec!(),vec!(), &mut vec![], crate_ast).0
     }
 
     // find the pat_ident paths in a crate