rustc: Add crust functions to the AST

Author: brson

src/comp/metadata/encoder.rs

@@ -312,7 +312,12 @@ fn encode_info_for_mod(ecx: @encode_ctxt, ebml_w: ebml::writer, md: _mod,
 }
 
 fn purity_fn_family(p: purity) -> char {
-    alt p { unsafe_fn { 'u' } pure_fn { 'p' } impure_fn { 'f' } }
+    alt p {
+      unsafe_fn { 'u' }
+      pure_fn { 'p' }
+      impure_fn { 'f' }
+      crust_fn { 'c' }
+    }
 }
 
 fn encode_info_for_item(ecx: @encode_ctxt, ebml_w: ebml::writer, item: @item,

src/comp/middle/typeck.rs

@@ -1535,7 +1535,7 @@ fn require_unsafe(sess: session, f_purity: ast::purity, sp: span) {
 fn require_impure(sess: session, f_purity: ast::purity, sp: span) {
     alt f_purity {
       ast::unsafe_fn { ret; }
-      ast::impure_fn { ret; }
+      ast::impure_fn | ast::crust_fn { ret; }
       ast::pure_fn {
         sess.span_err(sp, "Found impure expression in pure function decl");
       }
@@ -1568,7 +1568,7 @@ fn require_pure_call(ccx: @crate_ctxt, caller_purity: ast::purity,
       }
     };
     alt (caller_purity, callee_purity) {
-      (ast::impure_fn, ast::unsafe_fn) {
+      (ast::impure_fn, ast::unsafe_fn) | (ast::crust_fn, ast::unsafe_fn) {
         ccx.tcx.sess.span_err(sp, "safe function calls function marked \
                                    unsafe");
       }

src/comp/syntax/ast.rs

@@ -407,6 +407,7 @@ enum purity {
     pure_fn, // declared with "pure fn"
     unsafe_fn, // declared with "unsafe fn"
     impure_fn, // declared with "fn"
+    crust_fn, // declared with "crust fn"
 }
 
 enum ret_style {

src/comp/syntax/print/pprust.rs

@@ -1199,6 +1199,7 @@ fn print_fn(s: ps, decl: ast::fn_decl, name: ast::ident,
       ast::impure_fn { head(s, "fn"); }
       ast::unsafe_fn { head(s, "unsafe fn"); }
       ast::pure_fn { head(s, "pure fn"); }
+      ast::crust_fn { head(s, "crust fn"); }
     }
     word(s.s, name);
     print_type_params(s, typarams);