Manual merge of #22475 - alexcrichton:rollup, r=alexcrichton

 One windows bot failed spuriously.

6 files changed, 87 insertions, 16 deletions

diff --git a/src/libsyntax/ext/asm.rs b/src/libsyntax/ext/asm.rs
index 1ceda2e08dd..d8cba139fb5 100644
--- a/src/libsyntax/ext/asm.rs
+++ b/src/libsyntax/ext/asm.rs
@@ -18,6 +18,7 @@ use codemap;
 use codemap::Span;
 use ext::base;
 use ext::base::*;
+use feature_gate;
 use parse::token::InternedString;
 use parse::token;
 use ptr::P;
@@ -48,6 +49,12 @@ static OPTIONS: &'static [&'static str] = &["volatile", "alignstack", "intel"];
 
 pub fn expand_asm<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                        -> Box<base::MacResult+'cx> {
+    if !cx.ecfg.enable_asm() {
+        feature_gate::emit_feature_err(
+            &cx.parse_sess.span_diagnostic, "asm", sp, feature_gate::EXPLAIN_ASM);
+        return DummyResult::expr(sp);
+    }
+
     let mut p = cx.new_parser_from_tts(tts);
     let mut asm = InternedString::new("");
     let mut asm_str_style = None;
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 083039995ee..8800ffd1e9b 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/concat_idents.rs b/src/libsyntax/ext/concat_idents.rs
index 364cacd735c..63a8bd9ddf1 100644
--- a/src/libsyntax/ext/concat_idents.rs
+++ b/src/libsyntax/ext/concat_idents.rs
@@ -12,12 +12,21 @@ use ast;
 use codemap::Span;
 use ext::base::*;
 use ext::base;
+use feature_gate;
 use parse::token;
 use parse::token::{str_to_ident};
 use ptr::P;
 
 pub fn expand_syntax_ext<'cx>(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                               -> Box<base::MacResult+'cx> {
+    if !cx.ecfg.enable_concat_idents() {
+        feature_gate::emit_feature_err(&cx.parse_sess.span_diagnostic,
+                                       "concat_idents",
+                                       sp,
+                                       feature_gate::EXPLAIN_CONCAT_IDENTS);
+        return base::DummyResult::expr(sp);
+    }
+
     let mut res_str = String::new();
     for (i, e) in tts.iter().enumerate() {
         if i & 1 == 1 {
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index fd98f42c2ab..6b7cecee815 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;
@@ -1408,28 +1409,63 @@ 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 { allow_quote: true, .. }) => true,
+            _ => false,
+        }
+    }
+
+    pub fn enable_asm(&self) -> bool {
+        match self.features {
+            Some(&Features { allow_asm: true, .. }) => true,
+            _ => false,
+        }
+    }
+
+    pub fn enable_log_syntax(&self) -> bool {
+        match self.features {
+            Some(&Features { allow_log_syntax: true, .. }) => true,
+            _ => false,
+        }
+    }
+
+    pub fn enable_concat_idents(&self) -> bool {
+        match self.features {
+            Some(&Features { allow_concat_idents: true, .. }) => true,
+            _ => false,
+        }
+    }
+
+    pub fn enable_trace_macros(&self) -> bool {
+        match self.features {
+            Some(&Features { allow_trace_macros: 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);
 
@@ -1598,7 +1634,7 @@ 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())
     }
 
diff --git a/src/libsyntax/ext/log_syntax.rs b/src/libsyntax/ext/log_syntax.rs
index 30301e3b8cc..8173dd93f74 100644
--- a/src/libsyntax/ext/log_syntax.rs
+++ b/src/libsyntax/ext/log_syntax.rs
@@ -11,12 +11,20 @@
 use ast;
 use codemap;
 use ext::base;
+use feature_gate;
 use print;
 
 pub fn expand_syntax_ext<'cx>(cx: &'cx mut base::ExtCtxt,
                               sp: codemap::Span,
                               tts: &[ast::TokenTree])
                               -> Box<base::MacResult+'cx> {
+    if !cx.ecfg.enable_log_syntax() {
+        feature_gate::emit_feature_err(&cx.parse_sess.span_diagnostic,
+                                       "log_syntax",
+                                       sp,
+                                       feature_gate::EXPLAIN_LOG_SYNTAX);
+        return base::DummyResult::any(sp);
+    }
 
     cx.print_backtrace();
 
diff --git a/src/libsyntax/ext/trace_macros.rs b/src/libsyntax/ext/trace_macros.rs
index 76f7b7b0d7b..3fcc6a8d692 100644
--- a/src/libsyntax/ext/trace_macros.rs
+++ b/src/libsyntax/ext/trace_macros.rs
@@ -12,6 +12,7 @@ use ast;
 use codemap::Span;
 use ext::base::ExtCtxt;
 use ext::base;
+use feature_gate;
 use parse::token::keywords;
 
 
@@ -19,6 +20,15 @@ pub fn expand_trace_macros(cx: &mut ExtCtxt,
                            sp: Span,
                            tt: &[ast::TokenTree])
                            -> Box<base::MacResult+'static> {
+    if !cx.ecfg.enable_trace_macros() {
+        feature_gate::emit_feature_err(&cx.parse_sess.span_diagnostic,
+                                       "trace_macros",
+                                       sp,
+                                       feature_gate::EXPLAIN_TRACE_MACROS);
+        return base::DummyResult::any(sp);
+    }
+
+
     match tt {
         [ast::TtToken(_, ref tok)] if tok.is_keyword(keywords::True) => {
             cx.set_trace_macros(true);