Optimize include_bin! for large inputs

Previously an ExprLit was created *per byte* causing a huge increase in memory
bloat. This adds a new `lit_binary` to contain a literal of binary data, which
is currently only used by the include_bin! syntax extension. This massively
speeds up compilation times of the shootout-k-nucleotide-pipes test

    before:
        time: 469s
        memory: 6GB
        assertion failure in LLVM (section too large)

    after:
        time: 2.50s
        memory: 124MB

Closes #2598

3 files changed, 20 insertions, 8 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 08e1390a981..34b359ef3db 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -691,6 +691,7 @@ pub type lit = Spanned<lit_>;
 #[deriving(Clone, Eq, Encodable, Decodable, IterBytes)]
 pub enum lit_ {
     lit_str(@str, StrStyle),
+    lit_binary(@[u8]),
     lit_char(u32),
     lit_int(i64, int_ty),
     lit_uint(u64, uint_ty),
diff --git a/src/libsyntax/ext/source_util.rs b/src/libsyntax/ext/source_util.rs
index 1c13beb790d..dcfeb99365a 100644
--- a/src/libsyntax/ext/source_util.rs
+++ b/src/libsyntax/ext/source_util.rs
@@ -101,16 +101,19 @@ pub fn expand_include_str(cx: @ExtCtxt, sp: Span, tts: &[ast::token_tree])
 }
 
 pub fn expand_include_bin(cx: @ExtCtxt, sp: Span, tts: &[ast::token_tree])
-    -> base::MacResult {
+        -> base::MacResult
+{
+    use std::at_vec;
+
     let file = get_single_str_from_tts(cx, sp, tts, "include_bin!");
     match io::read_whole_file(&res_rel_file(cx, sp, &Path::new(file))) {
-      result::Ok(src) => {
-        let u8_exprs: ~[@ast::Expr] = src.iter().map(|char| cx.expr_u8(sp, *char)).collect();
-        base::MRExpr(cx.expr_vec(sp, u8_exprs))
-      }
-      result::Err(ref e) => {
-        cx.parse_sess().span_diagnostic.handler().fatal((*e))
-      }
+        result::Ok(src) => {
+            let v = at_vec::to_managed_move(src);
+            base::MRExpr(cx.expr_lit(sp, ast::lit_binary(v)))
+        }
+        result::Err(ref e) => {
+            cx.parse_sess().span_diagnostic.handler().fatal((*e))
+        }
     }
 }
 
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 607eb81102f..0d442dca9b6 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -2092,6 +2092,14 @@ pub fn print_literal(s: @ps, lit: &ast::lit) {
       ast::lit_bool(val) => {
         if val { word(s.s, "true"); } else { word(s.s, "false"); }
       }
+      ast::lit_binary(arr) => {
+        ibox(s, indent_unit);
+        word(s.s, "[");
+        commasep_cmnt(s, inconsistent, arr, |s, u| word(s.s, format!("{}", *u)),
+                      |_| lit.span);
+        word(s.s, "]");
+        end(s);
+      }
     }
 }