add new enum ast::StrStyle as field to ast::lit_str

For the benefit of the pretty printer we want to keep track of how
string literals in the ast were originally represented in the source
code.

This commit changes parser functions so they don't extract strings from
the token stream without at least also returning what style of string
literal it was. This is stored in the resulting ast node for string
literals, obviously, for the package id in `extern mod = r"package id"`
view items, for the inline asm in `asm!()` invocations.

For `asm!()`'s other arguments or for `extern "Rust" fn()` items, I just
the style of string, because it seemed disproportionally cumbersome to
thread that information through the string processing that happens with
those string literals, given the limited advantage raw string literals
would provide in these positions.

The other syntax extensions don't seem to store passed string literals
in the ast, so they also discard the style of strings they parse.

Author: ben0x539

src/librustc/front/test.rs

@@ -407,7 +407,7 @@ fn mk_test_desc_and_fn_rec(cx: &TestCtxt, test: &Test) -> @ast::Expr {
     debug2!("encoding {}", ast_util::path_name_i(path));
 
     let name_lit: ast::lit =
-        nospan(ast::lit_str(ast_util::path_name_i(path).to_managed()));
+        nospan(ast::lit_str(ast_util::path_name_i(path).to_managed(), ast::CookedStr));
 
     let name_expr = @ast::Expr {
           id: ast::DUMMY_NODE_ID,

src/librustc/metadata/creader.rs

@@ -142,7 +142,7 @@ fn visit_view_item(e: @mut Env, i: &ast::view_item) {
           let ident = token::ident_to_str(&ident);
           let meta_items = match path_opt {
               None => meta_items.clone(),
-              Some(p) => {
+              Some((p, _path_str_style)) => {
                   let p_path = Path(p);
                   match p_path.filestem() {
                       Some(s) =>

src/librustc/metadata/encoder.rs

@@ -1446,7 +1446,7 @@ fn encode_meta_item(ebml_w: &mut writer::Encoder, mi: @MetaItem) {
       }
       MetaNameValue(name, value) => {
         match value.node {
-          lit_str(value) => {
+          lit_str(value, _) => {
             ebml_w.start_tag(tag_meta_item_name_value);
             ebml_w.start_tag(tag_meta_item_name);
             ebml_w.writer.write(name.as_bytes());

src/librustc/middle/check_const.rs

@@ -86,7 +86,7 @@ pub fn check_pat(v: &mut CheckCrateVisitor, p: @Pat, _is_const: bool) {
         match e.node {
             ExprVstore(
                 @Expr { node: ExprLit(@codemap::Spanned {
-                    node: lit_str(_),
+                    node: lit_str(*),
                     _}),
                        _ },
                 ExprVstoreUniq
@@ -120,7 +120,7 @@ pub fn check_expr(v: &mut CheckCrateVisitor,
                           "disallowed operator in constant expression");
             return;
           }
-          ExprLit(@codemap::Spanned {node: lit_str(_), _}) => { }
+          ExprLit(@codemap::Spanned {node: lit_str(*), _}) => { }
           ExprBinary(*) | ExprUnary(*) => {
             if method_map.contains_key(&e.id) {
                 sess.span_err(e.span, "user-defined operators are not \

src/librustc/middle/const_eval.rs

@@ -475,7 +475,7 @@ pub fn eval_const_expr_partial<T: ty::ExprTyProvider>(tcx: &T, e: &Expr)
 
 pub fn lit_to_const(lit: &lit) -> const_val {
     match lit.node {
-      lit_str(s) => const_str(s),
+      lit_str(s, _) => const_str(s),
       lit_char(n) => const_uint(n as u64),
       lit_int(n, _) => const_int(n),
       lit_uint(n, _) => const_uint(n),

src/librustc/middle/trans/consts.rs

@@ -71,7 +71,7 @@ pub fn const_lit(cx: &mut CrateContext, e: &ast::Expr, lit: ast::lit)
       }
       ast::lit_bool(b) => C_bool(b),
       ast::lit_nil => C_nil(),
-      ast::lit_str(s) => C_estr_slice(cx, s)
+      ast::lit_str(s, _) => C_estr_slice(cx, s)
     }
 }
 

src/librustc/middle/trans/expr.rs

@@ -705,7 +705,7 @@ fn trans_rvalue_dps_unadjusted(bcx: @mut Block, expr: &ast::Expr,
                 args.iter().enumerate().map(|(i, arg)| (i, *arg)).collect();
             return trans_adt(bcx, repr, 0, numbered_fields, None, dest);
         }
-        ast::ExprLit(@codemap::Spanned {node: ast::lit_str(s), _}) => {
+        ast::ExprLit(@codemap::Spanned {node: ast::lit_str(s, _), _}) => {
             return tvec::trans_lit_str(bcx, expr, s, dest);
         }
         ast::ExprVstore(contents, ast::ExprVstoreSlice) |

src/librustc/middle/trans/tvec.rs

@@ -205,7 +205,7 @@ pub fn trans_slice_vstore(bcx: @mut Block,
 
     // Handle the &"..." case:
     match content_expr.node {
-        ast::ExprLit(@codemap::Spanned {node: ast::lit_str(s), span: _}) => {
+        ast::ExprLit(@codemap::Spanned {node: ast::lit_str(s, _), span: _}) => {
             return trans_lit_str(bcx, content_expr, s, dest);
         }
         _ => {}
@@ -296,7 +296,7 @@ pub fn trans_uniq_or_managed_vstore(bcx: @mut Block, heap: heap, vstore_expr: &a
         heap_exchange => {
             match content_expr.node {
                 ast::ExprLit(@codemap::Spanned {
-                    node: ast::lit_str(s), span
+                    node: ast::lit_str(s, _), span
                 }) => {
                     let llptrval = C_cstr(bcx.ccx(), s);
                     let llptrval = PointerCast(bcx, llptrval, Type::i8p());
@@ -357,7 +357,7 @@ pub fn write_content(bcx: @mut Block,
     let _indenter = indenter();
 
     match content_expr.node {
-        ast::ExprLit(@codemap::Spanned { node: ast::lit_str(s), _ }) => {
+        ast::ExprLit(@codemap::Spanned { node: ast::lit_str(s, _), _ }) => {
             match dest {
                 Ignore => {
                     return bcx;
@@ -490,7 +490,7 @@ pub fn elements_required(bcx: @mut Block, content_expr: &ast::Expr) -> uint {
     //! Figure out the number of elements we need to store this content
 
     match content_expr.node {
-        ast::ExprLit(@codemap::Spanned { node: ast::lit_str(s), _ }) => {
+        ast::ExprLit(@codemap::Spanned { node: ast::lit_str(s, _), _ }) => {
             s.len()
         },
         ast::ExprVec(ref es, _) => es.len(),

src/librustc/middle/ty.rs

@@ -3266,7 +3266,7 @@ pub fn expr_kind(tcx: ctxt,
         ast::ExprDoBody(*) |
         ast::ExprBlock(*) |
         ast::ExprRepeat(*) |
-        ast::ExprLit(@codemap::Spanned {node: lit_str(_), _}) |
+        ast::ExprLit(@codemap::Spanned {node: lit_str(*), _}) |
         ast::ExprVstore(_, ast::ExprVstoreSlice) |
         ast::ExprVstore(_, ast::ExprVstoreMutSlice) |
         ast::ExprVec(*) => {

src/librustc/middle/typeck/check/mod.rs

@@ -2259,7 +2259,7 @@ pub fn check_expr_with_unifier(fcx: @mut FnCtxt,
     match expr.node {
       ast::ExprVstore(ev, vst) => {
         let typ = match ev.node {
-          ast::ExprLit(@codemap::Spanned { node: ast::lit_str(_), _ }) => {
+          ast::ExprLit(@codemap::Spanned { node: ast::lit_str(*), _ }) => {
             let tt = ast_expr_vstore_to_vstore(fcx, ev, vst);
             ty::mk_estr(tcx, tt)
           }