From 20d8222e6a8a795272eea169c5415e5af28219fb Mon Sep 17 00:00:00 2001
From: "Felix S. Klock II" <pnkfelix@pnkfx.org>
Date: Sun, 15 Feb 2015 21:30:45 +0100
Subject: [PATCH] libsyntax: Pass feature set in ExpansionConfig, not just
 enable_quotes.

---
 src/librustc_driver/driver.rs |  3 ++-
 src/libsyntax/ext/base.rs     |  9 +++++----
 src/libsyntax/ext/expand.rs   | 32 ++++++++++++++++++++------------
 3 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/src/librustc_driver/driver.rs b/src/librustc_driver/driver.rs
index 12f5041cad14f..0eda86525ae44 100644
--- a/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@ -469,9 +469,10 @@ pub fn phase_2_configure_and_expand(sess: &Session,
                 new_path.extend(env::split_paths(&_old_path));
                 env::set_var("PATH", &env::join_paths(new_path.iter()).unwrap());
             }
+            let features = sess.features.borrow();
             let cfg = syntax::ext::expand::ExpansionConfig {
                 crate_name: crate_name.to_string(),
-                enable_quotes: sess.features.borrow().quote,
+                features: Some(&features),
                 recursion_limit: sess.recursion_limit.get(),
             };
             let ret = syntax::ext::expand::expand_crate(&sess.parse_sess,
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 64ae6162ef4e5..2a3636abf873b 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -439,7 +439,8 @@ impl BlockInfo {
 
 /// The base map of methods for expanding syntax extension
 /// AST nodes into full ASTs
-fn initial_syntax_expander_table(ecfg: &expand::ExpansionConfig) -> SyntaxEnv {
+fn initial_syntax_expander_table<'feat>(ecfg: &expand::ExpansionConfig<'feat>)
+                                        -> SyntaxEnv {
     // utility function to simplify creating NormalTT syntax extensions
     fn builtin_normal_expander(f: MacroExpanderFn) -> SyntaxExtension {
         NormalTT(box f, None)
@@ -470,7 +471,7 @@ fn initial_syntax_expander_table(ecfg: &expand::ExpansionConfig) -> SyntaxEnv {
     syntax_expanders.insert(intern("deriving"),
                             Decorator(box ext::deriving::expand_deprecated_deriving));
 
-    if ecfg.enable_quotes {
+    if ecfg.enable_quotes() {
         // Quasi-quoting expanders
         syntax_expanders.insert(intern("quote_tokens"),
                            builtin_normal_expander(
@@ -541,7 +542,7 @@ pub struct ExtCtxt<'a> {
     pub parse_sess: &'a parse::ParseSess,
     pub cfg: ast::CrateConfig,
     pub backtrace: ExpnId,
-    pub ecfg: expand::ExpansionConfig,
+    pub ecfg: expand::ExpansionConfig<'a>,
     pub use_std: bool,
 
     pub mod_path: Vec<ast::Ident> ,
@@ -554,7 +555,7 @@ pub struct ExtCtxt<'a> {
 
 impl<'a> ExtCtxt<'a> {
     pub fn new(parse_sess: &'a parse::ParseSess, cfg: ast::CrateConfig,
-               ecfg: expand::ExpansionConfig) -> ExtCtxt<'a> {
+               ecfg: expand::ExpansionConfig<'a>) -> ExtCtxt<'a> {
         let env = initial_syntax_expander_table(&ecfg);
         ExtCtxt {
             parse_sess: parse_sess,
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 131bbc4100546..267d732c9e66d 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -22,6 +22,7 @@ use attr::AttrMetaMethods;
 use codemap;
 use codemap::{Span, Spanned, ExpnInfo, NameAndSpan, MacroBang, MacroAttribute};
 use ext::base::*;
+use feature_gate::{Features};
 use fold;
 use fold::*;
 use parse;
@@ -1407,28 +1408,35 @@ fn new_span(cx: &ExtCtxt, sp: Span) -> Span {
     }
 }
 
-pub struct ExpansionConfig {
+pub struct ExpansionConfig<'feat> {
     pub crate_name: String,
-    pub enable_quotes: bool,
+    pub features: Option<&'feat Features>,
     pub recursion_limit: usize,
 }
 
-impl ExpansionConfig {
-    pub fn default(crate_name: String) -> ExpansionConfig {
+impl<'feat> ExpansionConfig<'feat> {
+    pub fn default(crate_name: String) -> ExpansionConfig<'static> {
         ExpansionConfig {
             crate_name: crate_name,
-            enable_quotes: false,
+            features: None,
             recursion_limit: 64,
         }
     }
+
+    pub fn enable_quotes(&self) -> bool {
+        match self.features {
+            Some(&Features { quote: true, .. }) => true,
+            _ => false,
+        }
+    }
 }
 
-pub fn expand_crate(parse_sess: &parse::ParseSess,
-                    cfg: ExpansionConfig,
-                    // these are the macros being imported to this crate:
-                    imported_macros: Vec<ast::MacroDef>,
-                    user_exts: Vec<NamedSyntaxExtension>,
-                    c: Crate) -> Crate {
+pub fn expand_crate<'feat>(parse_sess: &parse::ParseSess,
+                           cfg: ExpansionConfig<'feat>,
+                           // these are the macros being imported to this crate:
+                           imported_macros: Vec<ast::MacroDef>,
+                           user_exts: Vec<NamedSyntaxExtension>,
+                           c: Crate) -> Crate {
     let mut cx = ExtCtxt::new(parse_sess, c.config.clone(), cfg);
     cx.use_std = std_inject::use_std(&c);
 
@@ -1597,7 +1605,7 @@ mod test {
     // these following tests are quite fragile, in that they don't test what
     // *kind* of failure occurs.
 
-    fn test_ecfg() -> ExpansionConfig {
+    fn test_ecfg() -> ExpansionConfig<'static> {
         ExpansionConfig::default("test".to_string())
     }