Fix incremental compilation hashing.

Author: jseyfried

src/librustc_incremental/calculate_svh/svh_visitor.rs

@@ -18,7 +18,7 @@ use syntax::abi::Abi;
 use syntax::ast::{self, Name, NodeId};
 use syntax::attr;
 use syntax::parse::token;
-use syntax::symbol::InternedString;
+use syntax::symbol::{Symbol, InternedString};
 use syntax_pos::{Span, NO_EXPANSION, COMMAND_LINE_EXPN, BytePos};
 use syntax::tokenstream;
 use rustc::hir;
@@ -247,6 +247,8 @@ enum SawExprComponent<'a> {
     SawExprBinary(hir::BinOp_),
     SawExprUnary(hir::UnOp),
     SawExprLit(ast::LitKind),
+    SawExprLitStr(InternedString, ast::StrStyle),
+    SawExprLitFloat(InternedString, Option<ast::FloatTy>),
     SawExprCast,
     SawExprType,
     SawExprIf,
@@ -315,7 +317,7 @@ fn saw_expr<'a>(node: &'a Expr_,
         ExprUnary(op, _)         => {
             (SawExprUnary(op), unop_can_panic_at_runtime(op))
         }
-        ExprLit(ref lit)         => (SawExprLit(lit.node.clone()), false),
+        ExprLit(ref lit)         => (saw_lit(lit), false),
         ExprCast(..)             => (SawExprCast, false),
         ExprType(..)             => (SawExprType, false),
         ExprIf(..)               => (SawExprIf, false),
@@ -342,6 +344,15 @@ fn saw_expr<'a>(node: &'a Expr_,
     }
 }
 
+fn saw_lit(lit: &ast::Lit) -> SawExprComponent<'static> {
+    match lit.node {
+        ast::LitKind::Str(s, style) => SawExprLitStr(s.as_str(), style),
+        ast::LitKind::Float(s, ty) => SawExprLitFloat(s.as_str(), Some(ty)),
+        ast::LitKind::FloatUnsuffixed(s) => SawExprLitFloat(s.as_str(), None),
+        ref node @ _ => SawExprLit(node.clone()),
+    }
+}
+
 #[derive(Hash)]
 enum SawItemComponent {
     SawItemExternCrate,
@@ -875,23 +886,16 @@ impl<'a, 'hash, 'tcx> StrictVersionHashVisitor<'a, 'hash, 'tcx> {
 
         // ignoring span information, it doesn't matter here
         self.hash_discriminant(&meta_item.node);
-        let name = &*meta_item.name.as_str();
+        meta_item.name.as_str().len().hash(self.st);
+        meta_item.name.as_str().hash(self.st);
+
         match meta_item.node {
-            ast::MetaItemKind::Word => {
-                name.len().hash(self.st);
-                name.hash(self.st);
-            }
-            ast::MetaItemKind::NameValue(ref lit) => {
-                name.len().hash(self.st);
-                name.hash(self.st);
-                lit.node.hash(self.st);
-            }
+            ast::MetaItemKind::Word => {}
+            ast::MetaItemKind::NameValue(ref lit) => saw_lit(lit).hash(self.st),
             ast::MetaItemKind::List(ref items) => {
-                name.len().hash(self.st);
-                name.hash(self.st);
                 // Sort subitems so the hash does not depend on their order
                 let indices = self.indices_sorted_by(&items, |p| {
-                    (p.name(), fnv::hash(&p.literal().map(|i| &i.node)))
+                    (p.name().map(Symbol::as_str), fnv::hash(&p.literal().map(saw_lit)))
                 });
                 items.len().hash(self.st);
                 for (index, &item_index) in indices.iter().enumerate() {
@@ -903,7 +907,7 @@ impl<'a, 'hash, 'tcx> StrictVersionHashVisitor<'a, 'hash, 'tcx> {
                             self.hash_meta_item(meta_item);
                         }
                         ast::NestedMetaItemKind::Literal(ref lit) => {
-                            lit.node.hash(self.st);
+                            saw_lit(lit).hash(self.st);
                         }
                     }
                 }