---

yaml
---
r: 124854
b: refs/heads/master
c: 32f4d99
h: refs/heads/master
v: v3

Author: bors

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: febfb752d2775bb1e875634e45058e27a36dd714
+refs/heads/master: 32f4d996ea2bea69fe363dca4e6e09b91bbd83f3
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 9fc8394d3bce22ab483f98842434c84c396212ae
 refs/heads/try: ac70b438a8382389c9c9b59c66b14774bff46e10

trunk/src/libcore/iter.rs

@@ -1962,7 +1962,19 @@ pub struct Range<A> {
     one: A
 }
 
-/// Return an iterator over the range [start, stop)
+/// Returns an iterator over the given range [start, stop) (that is, starting
+/// at start (inclusive), and ending at stop (exclusive)).
+///
+/// # Example
+///
+/// ```rust
+/// let array = [0, 1, 2, 3, 4];
+///
+/// for i in range(0, 5u) {
+///     println!("{}", i);
+///     assert_eq!(i,  array[i]);
+/// }
+/// ```
 #[inline]
 pub fn range<A: Add<A, A> + PartialOrd + Clone + One>(start: A, stop: A) -> Range<A> {
     Range{state: start, stop: stop, one: One::one()}

trunk/src/libregex_macros/lib.rs

@@ -34,6 +34,7 @@ use syntax::ext::build::AstBuilder;
 use syntax::ext::base::{ExtCtxt, MacResult, MacExpr, DummyResult};
 use syntax::parse::token;
 use syntax::print::pprust;
+use syntax::fold::Folder;
 
 use rustc::plugin::Registry;
 
@@ -615,7 +616,7 @@ fn exec<'t>(which: ::regex::native::MatchKind, input: &'t str,
 /// Otherwise, logs an error with cx.span_err and returns None.
 fn parse(cx: &mut ExtCtxt, tts: &[ast::TokenTree]) -> Option<String> {
     let mut parser = cx.new_parser_from_tts(tts);
-    let entry = cx.expand_expr(parser.parse_expr());
+    let entry = cx.expander().fold_expr(parser.parse_expr());
     let regex = match entry.node {
         ast::ExprLit(lit) => {
             match lit.node {

trunk/src/librustc/middle/trans/_match.rs

@@ -202,12 +202,12 @@ use middle::resolve::DefMap;
 use middle::trans::adt;
 use middle::trans::base::*;
 use middle::trans::build::*;
+use middle::trans::build;
 use middle::trans::callee;
 use middle::trans::cleanup;
 use middle::trans::cleanup::CleanupMethods;
 use middle::trans::common::*;
 use middle::trans::consts;
-use middle::trans::controlflow;
 use middle::trans::datum::*;
 use middle::trans::expr::Dest;
 use middle::trans::expr;
@@ -220,14 +220,12 @@ use util::ppaux::{Repr, vec_map_to_string};
 
 use std;
 use std::collections::HashMap;
-use std::cell::Cell;
 use std::rc::Rc;
 use std::gc::{Gc};
 use syntax::ast;
 use syntax::ast::Ident;
 use syntax::codemap::Span;
 use syntax::fold::Folder;
-use syntax::parse::token::InternedString;
 
 #[deriving(PartialEq)]
 pub enum VecLenOpt {
@@ -301,20 +299,6 @@ fn trans_opt<'a>(mut bcx: &'a Block<'a>, o: &Opt) -> opt_result<'a> {
     }
 }
 
-fn variant_opt(bcx: &Block, pat_id: ast::NodeId) -> Opt {
-    let ccx = bcx.ccx();
-    let def = ccx.tcx.def_map.borrow().get_copy(&pat_id);
-    match def {
-        def::DefVariant(enum_id, var_id, _) => {
-            let variant = ty::enum_variant_with_id(ccx.tcx(), enum_id, var_id);
-            var(variant.disr_val, adt::represent_node(bcx, pat_id), var_id)
-        }
-        _ => {
-            ccx.sess().bug("non-variant or struct in variant_opt()");
-        }
-    }
-}
-
 #[deriving(Clone)]
 pub enum TransBindingMode {
     TrByCopy(/* llbinding */ ValueRef),
@@ -630,26 +614,15 @@ fn get_options(bcx: &Block, m: &[Match], col: uint) -> Vec<Opt> {
             ast::PatLit(l) => {
                 add_to_set(ccx.tcx(), &mut found, lit(l));
             }
-            ast::PatIdent(..) => {
+            ast::PatIdent(..) | ast::PatEnum(..) | ast::PatStruct(..) => {
                 // This is either an enum variant or a variable binding.
                 let opt_def = ccx.tcx.def_map.borrow().find_copy(&cur.id);
                 match opt_def {
-                    Some(def::DefVariant(..)) => {
-                        add_to_set(ccx.tcx(), &mut found,
-                                   variant_opt(bcx, cur.id));
-                    }
-                    _ => {}
-                }
-            }
-            ast::PatEnum(..) | ast::PatStruct(..) => {
-                // This could be one of: a tuple-like enum variant, a
-                // struct-like enum variant, or a struct.
-                let opt_def = ccx.tcx.def_map.borrow().find_copy(&cur.id);
-                match opt_def {
-                    Some(def::DefFn(..)) |
-                    Some(def::DefVariant(..)) => {
+                    Some(def::DefVariant(enum_id, var_id, _)) => {
+                        let variant = ty::enum_variant_with_id(ccx.tcx(), enum_id, var_id);
                         add_to_set(ccx.tcx(), &mut found,
-                                   variant_opt(bcx, cur.id));
+                                   var(variant.disr_val,
+                                       adt::represent_node(bcx, cur.id), var_id));
                     }
                     _ => {}
                 }
@@ -795,56 +768,33 @@ fn any_irrefutable_adt_pat(bcx: &Block, m: &[Match], col: uint) -> bool {
     })
 }
 
-struct DynamicFailureHandler<'a> {
-    bcx: &'a Block<'a>,
-    sp: Span,
-    msg: InternedString,
-    finished: Cell<Option<BasicBlockRef>>,
-}
-
-impl<'a> DynamicFailureHandler<'a> {
-    fn handle_fail(&self) -> BasicBlockRef {
-        match self.finished.get() {
-            Some(bb) => return bb,
-            _ => (),
-        }
-
-        let fcx = self.bcx.fcx;
-        let fail_cx = fcx.new_block(false, "case_fallthrough", None);
-        controlflow::trans_fail(fail_cx, self.sp, self.msg.clone());
-        self.finished.set(Some(fail_cx.llbb));
-        fail_cx.llbb
-    }
-}
-
 /// What to do when the pattern match fails.
 enum FailureHandler<'a> {
     Infallible,
     JumpToBasicBlock(BasicBlockRef),
-    DynamicFailureHandlerClass(Box<DynamicFailureHandler<'a>>),
+    Unreachable
 }
 
 impl<'a> FailureHandler<'a> {
     fn is_infallible(&self) -> bool {
         match *self {
             Infallible => true,
-            _ => false,
+            _ => false
         }
     }
 
     fn is_fallible(&self) -> bool {
         !self.is_infallible()
     }
 
-    fn handle_fail(&self) -> BasicBlockRef {
+    fn handle_fail(&self, bcx: &Block) {
         match *self {
-            Infallible => {
-                fail!("attempted to fail in infallible failure handler!")
-            }
-            JumpToBasicBlock(basic_block) => basic_block,
-            DynamicFailureHandlerClass(ref dynamic_failure_handler) => {
-                dynamic_failure_handler.handle_fail()
-            }
+            Infallible =>
+                fail!("attempted to fail in infallible failure handler!"),
+            JumpToBasicBlock(basic_block) =>
+                Br(bcx, basic_block),
+            Unreachable =>
+                build::Unreachable(bcx)
         }
     }
 }
@@ -1005,7 +955,7 @@ fn compile_guard<'a, 'b>(
             // condition explicitly rather than (possibly) falling back to
             // the default arm.
             &JumpToBasicBlock(_) if m.len() == 1 && has_genuine_default => {
-                Br(bcx, chk.handle_fail());
+                chk.handle_fail(bcx);
             }
             _ => {
                 compile_submatch(bcx, m, vals, chk, has_genuine_default);
@@ -1030,7 +980,7 @@ fn compile_submatch<'a, 'b>(
     let mut bcx = bcx;
     if m.len() == 0u {
         if chk.is_fallible() {
-            Br(bcx, chk.handle_fail());
+            chk.handle_fail(bcx);
         }
         return;
     }
@@ -1301,7 +1251,7 @@ fn compile_submatch_continue<'a, 'b>(
             // condition explicitly rather than (eventually) falling back to
             // the last default arm.
             &JumpToBasicBlock(_) if defaults.len() == 1 && has_genuine_default => {
-                Br(else_cx, chk.handle_fail());
+                chk.handle_fail(else_cx);
             }
             _ => {
                 compile_submatch(else_cx,
@@ -1395,21 +1345,10 @@ fn trans_match_inner<'a>(scope_cx: &'a Block<'a>,
     }
 
     let t = node_id_type(bcx, discr_expr.id);
-    let chk = {
-        if ty::type_is_empty(tcx, t) {
-            // Special case for empty types
-            let fail_cx = Cell::new(None);
-            let fail_handler = box DynamicFailureHandler {
-                bcx: scope_cx,
-                sp: discr_expr.span,
-                msg: InternedString::new("scrutinizing value that can't \
-                                          exist"),
-                finished: fail_cx,
-            };
-            DynamicFailureHandlerClass(fail_handler)
-        } else {
-            Infallible
-        }
+    let chk = if ty::type_is_empty(tcx, t) {
+        Unreachable
+    } else {
+        Infallible
     };
 
     let arm_datas: Vec<ArmData> = arms.iter().map(|arm| ArmData {

trunk/src/libsyntax/ext/base.rs

@@ -20,9 +20,11 @@ use parse::token;
 use parse::token::{InternedString, intern, str_to_ident};
 use util::small_vector::SmallVector;
 use ext::mtwt;
+use fold::Folder;
 
 use std::collections::HashMap;
 use std::gc::{Gc, GC};
+use std::rc::Rc;
 
 // new-style macro! tt code:
 //
@@ -104,9 +106,9 @@ pub type IdentMacroExpanderFn =
 /// just into the compiler's internal macro table, for `make_def`).
 pub trait MacResult {
     /// Define a new macro.
-    // this particular flavor should go away; the idea that a macro might
-    // expand into either a macro definition or an expression, depending
-    // on what the context wants, is kind of silly.
+    // this should go away; the idea that a macro might expand into
+    // either a macro definition or an expression, depending on what
+    // the context wants, is kind of silly.
     fn make_def(&self) -> Option<MacroDef> {
         None
     }
@@ -314,7 +316,7 @@ impl BlockInfo {
 
 /// The base map of methods for expanding syntax extension
 /// AST nodes into full ASTs
-pub fn syntax_expander_table() -> SyntaxEnv {
+fn initial_syntax_expander_table() -> SyntaxEnv {
     // utility function to simplify creating NormalTT syntax extensions
     fn builtin_normal_expander(f: MacroExpanderFn) -> SyntaxExtension {
         NormalTT(box BasicMacroExpander {
@@ -431,7 +433,9 @@ pub struct ExtCtxt<'a> {
 
     pub mod_path: Vec<ast::Ident> ,
     pub trace_mac: bool,
-    pub exported_macros: Vec<Gc<ast::Item>>
+    pub exported_macros: Vec<Gc<ast::Item>>,
+
+    pub syntax_env: SyntaxEnv,
 }
 
 impl<'a> ExtCtxt<'a> {
@@ -445,22 +449,18 @@ impl<'a> ExtCtxt<'a> {
             ecfg: ecfg,
             trace_mac: false,
             exported_macros: Vec::new(),
+            syntax_env: initial_syntax_expander_table(),
         }
     }
 
-    pub fn expand_expr(&mut self, mut e: Gc<ast::Expr>) -> Gc<ast::Expr> {
-        loop {
-            match e.node {
-                ast::ExprMac(..) => {
-                    let mut expander = expand::MacroExpander {
-                        extsbox: syntax_expander_table(),
-                        cx: self,
-                    };
-                    e = expand::expand_expr(e, &mut expander);
-                }
-                _ => return e
-            }
-        }
+    #[deprecated = "Replaced with `expander().fold_expr()`"]
+    pub fn expand_expr(&mut self, e: Gc<ast::Expr>) -> Gc<ast::Expr> {
+        self.expander().fold_expr(e)
+    }
+
+    /// Returns a `Folder` for deeply expanding all macros in a AST node.
+    pub fn expander<'b>(&'b mut self) -> expand::MacroExpander<'b, 'a> {
+        expand::MacroExpander { cx: self }
     }
 
     pub fn new_parser_from_tts(&self, tts: &[ast::TokenTree])
@@ -570,7 +570,7 @@ impl<'a> ExtCtxt<'a> {
 pub fn expr_to_string(cx: &mut ExtCtxt, expr: Gc<ast::Expr>, err_msg: &str)
                    -> Option<(InternedString, ast::StrStyle)> {
     // we want to be able to handle e.g. concat("foo", "bar")
-    let expr = cx.expand_expr(expr);
+    let expr = cx.expander().fold_expr(expr);
     match expr.node {
         ast::ExprLit(l) => match l.node {
             ast::LitStr(ref s, style) => return Some(((*s).clone(), style)),
@@ -627,7 +627,7 @@ pub fn get_exprs_from_tts(cx: &mut ExtCtxt,
     let mut p = cx.new_parser_from_tts(tts);
     let mut es = Vec::new();
     while p.token != token::EOF {
-        es.push(cx.expand_expr(p.parse_expr()));
+        es.push(cx.expander().fold_expr(p.parse_expr()));
         if p.eat(&token::COMMA) {
             continue;
         }
@@ -642,10 +642,13 @@ pub fn get_exprs_from_tts(cx: &mut ExtCtxt,
 /// In order to have some notion of scoping for macros,
 /// we want to implement the notion of a transformation
 /// environment.
-
+///
 /// This environment maps Names to SyntaxExtensions.
+pub struct SyntaxEnv {
+    chain: Vec<MapChainFrame> ,
+}
 
-//impl question: how to implement it? Initially, the
+// impl question: how to implement it? Initially, the
 // env will contain only macros, so it might be painful
 // to add an empty frame for every context. Let's just
 // get it working, first....
@@ -657,15 +660,11 @@ pub fn get_exprs_from_tts(cx: &mut ExtCtxt,
 
 struct MapChainFrame {
     info: BlockInfo,
-    map: HashMap<Name, SyntaxExtension>,
-}
-
-pub struct SyntaxEnv {
-    chain: Vec<MapChainFrame> ,
+    map: HashMap<Name, Rc<SyntaxExtension>>,
 }
 
 impl SyntaxEnv {
-    pub fn new() -> SyntaxEnv {
+    fn new() -> SyntaxEnv {
         let mut map = SyntaxEnv { chain: Vec::new() };
         map.push_frame();
         map
@@ -692,18 +691,18 @@ impl SyntaxEnv {
         unreachable!()
     }
 
-    pub fn find<'a>(&'a self, k: &Name) -> Option<&'a SyntaxExtension> {
+    pub fn find(&self, k: &Name) -> Option<Rc<SyntaxExtension>> {
         for frame in self.chain.iter().rev() {
             match frame.map.find(k) {
-                Some(v) => return Some(v),
+                Some(v) => return Some(v.clone()),
                 None => {}
             }
         }
         None
     }
 
     pub fn insert(&mut self, k: Name, v: SyntaxExtension) {
-        self.find_escape_frame().map.insert(k, v);
+        self.find_escape_frame().map.insert(k, Rc::new(v));
     }
 
     pub fn info<'a>(&'a mut self) -> &'a mut BlockInfo {