From 91d3c364303c3a057feadd40adef0880531e08cc Mon Sep 17 00:00:00 2001
From: John Clements <clements@racket-lang.org>
Date: Tue, 25 Jun 2013 11:43:52 -0700
Subject: adding test case to check marking/unmarking

---
 src/libsyntax/ext/expand.rs | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

(limited to 'src/libsyntax/ext')

diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index fbaeab03e8a..25edcf63faa 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -23,7 +23,7 @@ use opt_vec;
 use parse;
 use parse::{parse_item_from_source_str};
 use parse::token;
-use parse::token::{fresh_name, ident_to_str, intern};
+use parse::token::{fresh_mark, fresh_name, ident_to_str, intern};
 use visit;
 use visit::Visitor;
 
@@ -67,7 +67,9 @@ pub fn expand_expr(extsbox: @mut SyntaxEnv,
                                 },
                             });
 
-                            let expanded = match expandfun(cx, mac.span, *tts) {
+                            let fm = fresh_mark();
+                            let marked_tts = mark_tts(*tts,fm);
+                            let expanded = match expandfun(cx, mac.span, marked_tts) {
                                 MRExpr(e) => e,
                                 MRAny(expr_maker,_,_) => expr_maker(),
                                 _ => {
@@ -259,6 +261,12 @@ pub fn expand_expr(extsbox: @mut SyntaxEnv,
     }
 }
 
+// apply a fresh mark to the given token trees. Used prior to expansion of a macro.
+fn mark_tts(tts : &[token_tree], m : Mrk) -> ~[token_tree] {
+    fold_tts(tts,new_ident_marker(m))
+}
+
+
 // This is a secondary mechanism for invoking syntax extensions on items:
 // "decorator" attributes, such as #[auto_encode]. These are invoked by an
 // attribute prefixing an item, and are interpreted by feeding the item
@@ -1285,7 +1293,7 @@ pub fn new_ident_renamer(from: ast::Ident,
 
 
 // update the ctxts in a path to get a mark node
-pub fn new_ident_marker(mark: uint) ->
+pub fn new_ident_marker(mark: Mrk) ->
     @fn(ast::Ident)->ast::Ident {
     |id : ast::Ident|
     ast::Ident{
@@ -1461,18 +1469,18 @@ mod test {
 
     #[test]
     fn automatic_renaming () {
-        // "fn a() -> int { let b = 13; let c = b; b+c }"
-        //    --> b & c should get new names, in the expr too.
-        // "macro_rules! f (($x:ident) => ($x + b)) fn a() -> int { let b = 13; f!(b)}"
-        //    --> one should be renamed, one should not.
-
         let teststrs =
             ~[// b & c should get new names throughout, in the expr too:
                 @"fn a() -> int { let b = 13; let c = b; b+c }",
                 // the use of b before the + should be renamed, the other one not:
                 @"macro_rules! f (($x:ident) => ($x + b)) fn a() -> int { let b = 13; f!(b)}",
                 // the b before the plus should not be renamed (requires marks)
-                @"macro_rules! f (($x:ident) => ({let b=9; ($x + b)})) fn a() -> int { f!(b)}"];
+                @"macro_rules! f (($x:ident) => ({let b=9; ($x + b)})) fn a() -> int { f!(b)}",
+                // the z flows into and out of two macros (g & f) along one path, and one (just g) along the
+                // other, so the result of the whole thing should be "let z_123 = 3; z_123"
+                @"macro_rules! g (($x:ident) => ({macro_rules! f(($y:ident)=>({let $y=3;$x}));f!($x)}))
+                   fn a(){g!(z)}"
+            ];
         for s in teststrs.iter() {
             // we need regexps to test these!
             std::io::println(expand_and_resolve_and_pretty_print(*s));
-- 
cgit 1.4.1-3-g733a5