---

yaml
---
r: 142903
b: refs/heads/try2
c: 4bd716a
h: refs/heads/master
i:
  142901: 03d4eba
  142899: 80b4427
  142895: 6dae4f3
v: v3

Author: bors

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: 712ac836c63c3ae98daf9fb98b7b96ed73347848
+refs/heads/try2: 4bd716ac8eb60dbaced9e3d2bafee89b713a7849
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/doc/rust.md

@@ -1417,14 +1417,83 @@ names are effectively reserved. Some significant attributes include:
 * The `lang` attribute, for custom definitions of traits and functions that are known to the Rust compiler (see [Language items](#language-items)).
 * The `link` attribute, for describing linkage metadata for a crate.
 * The `test` attribute, for marking functions as unit tests.
-* The `allow`, `warn`, `forbid`, and `deny` attributes, for controlling lint checks. Lint checks supported
-by the compiler can be found via `rustc -W help`.
+* The `allow`, `warn`, `forbid`, and `deny` attributes, for
+  controlling lint checks (see [Lint check attributes](#lint-check-attributes)).
 * The `deriving` attribute, for automatically generating
   implementations of certain traits.
 * The `static_assert` attribute, for asserting that a static bool is true at compiletime
 
 Other attributes may be added or removed during development of the language.
 
+### Lint check attributes
+
+A lint check names a potentially undesirable coding pattern, such as
+unreachable code or omitted documentation, for the static entity to
+which the attribute applies.
+
+For any lint check `C`:
+
+ * `warn(C)` warns about violations of `C` but continues compilation,
+ * `deny(C)` signals an error after encountering a violation of `C`,
+ * `allow(C)` overrides the check for `C` so that violations will go
+    unreported,
+ * `forbid(C)` is the same as `deny(C)`, but also forbids uses of
+   `allow(C)` within the entity.
+
+The lint checks supported by the compiler can be found via `rustc -W help`,
+along with their default settings.
+
+~~~{.xfail-test}
+mod m1 {
+    // Missing documentation is ignored here
+    #[allow(missing_doc)]
+    pub fn undocumented_one() -> int { 1 }
+
+    // Missing documentation signals a warning here
+    #[warn(missing_doc)]
+    pub fn undocumented_too() -> int { 2 }
+
+    // Missing documentation signals an error here
+    #[deny(missing_doc)]
+    pub fn undocumented_end() -> int { 3 }
+}
+~~~
+
+This example shows how one can use `allow` and `warn` to toggle
+a particular check on and off.
+
+~~~
+#[warn(missing_doc)]
+mod m2{
+    #[allow(missing_doc)]
+    mod nested {
+        // Missing documentation is ignored here
+        pub fn undocumented_one() -> int { 1 }
+
+        // Missing documentation signals a warning here,
+        // despite the allow above.
+        #[warn(missing_doc)]
+        pub fn undocumented_two() -> int { 2 }
+    }
+
+    // Missing documentation signals a warning here
+    pub fn undocumented_too() -> int { 3 }
+}
+~~~
+
+This example shows how one can use `forbid` to disallow uses
+of `allow` for that lint check.
+
+~~~{.xfail-test}
+#[forbid(missing_doc)]
+mod m3 {
+    // Attempting to toggle warning signals an error here
+    #[allow(missing_doc)]
+    /// Returns 2.
+    pub fn undocumented_too() -> int { 2 }
+}
+~~~
+
 ### Language items
 
 Some primitive Rust operations are defined in Rust code,

branches/try2/src/libextra/smallintmap.rs

@@ -161,8 +161,8 @@ impl<V> SmallIntMap<V> {
     /// Visit all key-value pairs in reverse order
     pub fn each_reverse<'a>(&'a self, it: &fn(uint, &'a V) -> bool) -> bool {
         for uint::range_rev(self.v.len(), 0) |i| {
-            match self.v[i - 1] {
-              Some(ref elt) => if !it(i - 1, elt) { return false; },
+            match self.v[i] {
+              Some(ref elt) => if !it(i, elt) { return false; },
               None => ()
             }
         }

branches/try2/src/librustc/driver/driver.rs

@@ -194,6 +194,10 @@ pub fn compile_rest(sess: Session,
         //   mod bar { macro_rules! baz!(() => {{}}) }
         //
         // baz! should not use this definition unless foo is enabled.
+        crate = time(time_passes, ~"std macros injection", ||
+                     syntax::ext::expand::inject_std_macros(sess.parse_sess, copy cfg,
+                                                             crate));
+
         crate = time(time_passes, ~"configuration 1", ||
                      front::config::strip_unconfigured_items(crate));
 
@@ -214,7 +218,7 @@ pub fn compile_rest(sess: Session,
     assert!(phases.from != cu_no_trans);
 
     let (llcx, llmod, link_meta) = {
-        crate = time(time_passes, ~"extra injection", ||
+        crate = time(time_passes, ~"std injection", ||
                      front::std_inject::maybe_inject_libstd_ref(sess, crate));
 
         let ast_map = time(time_passes, ~"ast indexing", ||

branches/try2/src/librustc/middle/const_eval.rs

@@ -165,10 +165,58 @@ pub fn classify(e: &expr,
 pub fn lookup_const(tcx: ty::ctxt, e: &expr) -> Option<@expr> {
     match tcx.def_map.find(&e.id) {
         Some(&ast::def_static(def_id, false)) => lookup_const_by_id(tcx, def_id),
+        Some(&ast::def_variant(enum_def, variant_def)) => lookup_variant_by_id(tcx,
+                                                                               enum_def,
+                                                                               variant_def),
         _ => None
     }
 }
 
+pub fn lookup_variant_by_id(tcx: ty::ctxt,
+                            enum_def: ast::def_id,
+                            variant_def: ast::def_id)
+                       -> Option<@expr> {
+    fn variant_expr(variants: &[ast::variant], id: ast::node_id) -> Option<@expr> {
+        for variants.iter().advance |variant| {
+            if variant.node.id == id {
+                return variant.node.disr_expr;
+            }
+        }
+        None
+    }
+
+    if ast_util::is_local(enum_def) {
+        match tcx.items.find(&enum_def.node) {
+            None => None,
+            Some(&ast_map::node_item(it, _)) => match it.node {
+                item_enum(ast::enum_def { variants: ref variants }, _) => {
+                    variant_expr(*variants, variant_def.node)
+                }
+                _ => None
+            },
+            Some(_) => None
+        }
+    } else {
+        let maps = astencode::Maps {
+            root_map: @mut HashMap::new(),
+            method_map: @mut HashMap::new(),
+            vtable_map: @mut HashMap::new(),
+            write_guard_map: @mut HashSet::new(),
+            capture_map: @mut HashMap::new()
+        };
+        match csearch::maybe_get_item_ast(tcx, enum_def,
+            |a, b, c, d| astencode::decode_inlined_item(a, b, maps, /*bar*/ copy c, d)) {
+            csearch::found(ast::ii_item(item)) => match item.node {
+                item_enum(ast::enum_def { variants: ref variants }, _) => {
+                    variant_expr(*variants, variant_def.node)
+                }
+                _ => None
+            },
+            _ => None
+        }
+    }
+}
+
 pub fn lookup_const_by_id(tcx: ty::ctxt,
                           def_id: ast::def_id)
                        -> Option<@expr> {
@@ -237,13 +285,13 @@ pub enum const_val {
 }
 
 pub fn eval_const_expr(tcx: middle::ty::ctxt, e: &expr) -> const_val {
-    match eval_const_expr_partial(tcx, e) {
+    match eval_const_expr_partial(&tcx, e) {
         Ok(r) => r,
         Err(s) => tcx.sess.span_fatal(e.span, s)
     }
 }
 
-pub fn eval_const_expr_partial(tcx: middle::ty::ctxt, e: &expr)
+pub fn eval_const_expr_partial<T: ty::ExprTyProvider>(tcx: &T, e: &expr)
                             -> Result<const_val, ~str> {
     use middle::ty;
     fn fromb(b: bool) -> Result<const_val, ~str> { Ok(const_int(b as i64)) }
@@ -360,7 +408,7 @@ pub fn eval_const_expr_partial(tcx: middle::ty::ctxt, e: &expr)
         }
       }
       expr_cast(base, _) => {
-        let ety = ty::expr_ty(tcx, e);
+        let ety = tcx.expr_ty(e);
         let base = eval_const_expr_partial(tcx, base);
         match /*bad*/copy base {
             Err(_) => base,
@@ -390,8 +438,8 @@ pub fn eval_const_expr_partial(tcx: middle::ty::ctxt, e: &expr)
         }
       }
       expr_path(_) => {
-          match lookup_const(tcx, e) {
-              Some(actual_e) => eval_const_expr_partial(tcx, actual_e),
+          match lookup_const(tcx.ty_ctxt(), e) {
+              Some(actual_e) => eval_const_expr_partial(&tcx.ty_ctxt(), actual_e),
               None => Err(~"Non-constant path in constant expr")
           }
       }

branches/try2/src/librustc/middle/kind.rs

@@ -309,7 +309,7 @@ pub fn check_expr(e: @expr, (cx, v): (Context, visit::vt<Context>)) {
                        "explicit copy requires a copyable argument");
         }
         expr_repeat(element, count_expr, _) => {
-            let count = ty::eval_repeat_count(cx.tcx, count_expr);
+            let count = ty::eval_repeat_count(&cx.tcx, count_expr);
             if count > 1 {
                 let element_ty = ty::expr_ty(cx.tcx, element);
                 check_copy(cx, element_ty, element.span,

branches/try2/src/librustc/middle/trans/base.rs

@@ -1530,7 +1530,7 @@ pub fn alloca_maybe_zeroed(cx: block, ty: Type, name: &str, zero: bool) -> Value
     let _icx = push_ctxt("alloca");
     if cx.unreachable {
         unsafe {
-            return llvm::LLVMGetUndef(ty.to_ref());
+            return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
         }
     }
     let initcx = base::raw_block(cx.fcx, false, cx.fcx.get_llstaticallocas());

branches/try2/src/librustc/middle/trans/build.rs

@@ -569,15 +569,17 @@ pub fn LoadRangeAssert(cx: block, PointerVal: ValueRef, lo: c_ulonglong,
                        hi: c_ulonglong, signed: lib::llvm::Bool) -> ValueRef {
     let value = Load(cx, PointerVal);
 
-    unsafe {
-        let t = llvm::LLVMGetElementType(llvm::LLVMTypeOf(PointerVal));
-        let min = llvm::LLVMConstInt(t, lo, signed);
-        let max = llvm::LLVMConstInt(t, hi, signed);
-
-        do [min, max].as_imm_buf |ptr, len| {
-            llvm::LLVMSetMetadata(value, lib::llvm::MD_range as c_uint,
-                                  llvm::LLVMMDNodeInContext(cx.fcx.ccx.llcx,
-                                                            ptr, len as c_uint));
+    if !cx.unreachable {
+        unsafe {
+            let t = llvm::LLVMGetElementType(llvm::LLVMTypeOf(PointerVal));
+            let min = llvm::LLVMConstInt(t, lo, signed);
+            let max = llvm::LLVMConstInt(t, hi, signed);
+
+            do [min, max].as_imm_buf |ptr, len| {
+                llvm::LLVMSetMetadata(value, lib::llvm::MD_range as c_uint,
+                                      llvm::LLVMMDNodeInContext(cx.fcx.ccx.llcx,
+                                                                ptr, len as c_uint));
+            }
         }
     }
 

branches/try2/src/librustc/middle/trans/controlflow.rs

@@ -63,6 +63,38 @@ pub fn trans_if(bcx: block,
     let _indenter = indenter();
 
     let _icx = push_ctxt("trans_if");
+
+    match cond.node {
+        // `if true` and `if false` can be trans'd more efficiently,
+        // by dropping branches that are known to be impossible.
+        ast::expr_lit(@ref l) => match l.node {
+            ast::lit_bool(true) => {
+                // if true { .. } [else { .. }]
+                let then_bcx_in = scope_block(bcx, thn.info(), "if_true_then");
+                let then_bcx_out = trans_block(then_bcx_in, thn, dest);
+                let then_bcx_out = trans_block_cleanups(then_bcx_out,
+                                                        block_cleanups(then_bcx_in));
+                Br(bcx, then_bcx_in.llbb);
+                return then_bcx_out;
+            }
+            ast::lit_bool(false) => {
+                match els {
+                    // if false { .. } else { .. }
+                    Some(elexpr) => {
+                        let (else_bcx_in, else_bcx_out) =
+                            trans_if_else(bcx, elexpr, dest, "if_false_else");
+                        Br(bcx, else_bcx_in.llbb);
+                        return else_bcx_out;
+                    }
+                    // if false { .. }
+                    None => return bcx,
+                }
+            }
+            _ => {}
+        },
+        _ => {}
+    }
+
     let Result {bcx, val: cond_val} =
         expr::trans_to_datum(bcx, cond).to_result();
 
@@ -80,22 +112,8 @@ pub fn trans_if(bcx: block,
     // 'else' context
     let (else_bcx_in, next_bcx) = match els {
       Some(elexpr) => {
-        let else_bcx_in = scope_block(bcx, els.info(), "else");
-        let else_bcx_out = match elexpr.node {
-          ast::expr_if(_, _, _) => {
-            let elseif_blk = ast_util::block_from_expr(elexpr);
-            trans_block(else_bcx_in, &elseif_blk, dest)
-          }
-          ast::expr_block(ref blk) => {
-            trans_block(else_bcx_in, blk, dest)
-          }
-          // would be nice to have a constraint on ifs
-          _ => bcx.tcx().sess.bug("strange alternative in if")
-        };
-        let else_bcx_out = trans_block_cleanups(else_bcx_out,
-                                                block_cleanups(else_bcx_in));
-
-        (else_bcx_in, join_blocks(bcx, [then_bcx_out, else_bcx_out]))
+          let (else_bcx_in, else_bcx_out) = trans_if_else(bcx, elexpr, dest, "else");
+          (else_bcx_in, join_blocks(bcx, [then_bcx_out, else_bcx_out]))
       }
       _ => {
           let next_bcx = sub_block(bcx, "next");
@@ -109,7 +127,27 @@ pub fn trans_if(bcx: block,
            then_bcx_in.to_str(), else_bcx_in.to_str());
 
     CondBr(bcx, cond_val, then_bcx_in.llbb, else_bcx_in.llbb);
-    next_bcx
+    return next_bcx;
+
+    // trans `else [ if { .. } ... | { .. } ]`
+    fn trans_if_else(bcx: block, elexpr: @ast::expr,
+                     dest: expr::Dest, scope_name: &str) -> (block, block) {
+        let else_bcx_in = scope_block(bcx, elexpr.info(), scope_name);
+        let else_bcx_out = match elexpr.node {
+            ast::expr_if(_, _, _) => {
+                let elseif_blk = ast_util::block_from_expr(elexpr);
+                trans_block(else_bcx_in, &elseif_blk, dest)
+            }
+            ast::expr_block(ref blk) => {
+                trans_block(else_bcx_in, blk, dest)
+            }
+            // would be nice to have a constraint on ifs
+            _ => bcx.tcx().sess.bug("strange alternative in if")
+        };
+        let else_bcx_out = trans_block_cleanups(else_bcx_out,
+                                                block_cleanups(else_bcx_in));
+        (else_bcx_in, else_bcx_out)
+    }
 }
 
 pub fn join_blocks(parent_bcx: block, in_cxs: &[block]) -> block {

branches/try2/src/librustc/middle/trans/datum.rs

@@ -413,7 +413,7 @@ impl Datum {
     pub fn to_value_datum(&self, bcx: block) -> Datum {
         /*!
          *
-         * Yields a by-ref form of this datum.  This may involve
+         * Yields a by-value form of this datum.  This may involve
          * creation of a temporary stack slot.  The value returned by
          * this function is not separately rooted from this datum, so
          * it will not live longer than the current datum. */

branches/try2/src/librustc/middle/trans/tvec.rs

@@ -417,7 +417,7 @@ pub fn write_content(bcx: block,
                     return expr::trans_into(bcx, element, Ignore);
                 }
                 SaveIn(lldest) => {
-                    let count = ty::eval_repeat_count(bcx.tcx(), count_expr);
+                    let count = ty::eval_repeat_count(&bcx.tcx(), count_expr);
                     if count == 0 {
                         return bcx;
                     }
@@ -509,7 +509,7 @@ pub fn elements_required(bcx: block, content_expr: &ast::expr) -> uint {
         },
         ast::expr_vec(ref es, _) => es.len(),
         ast::expr_repeat(_, count_expr, _) => {
-            ty::eval_repeat_count(bcx.tcx(), count_expr)
+            ty::eval_repeat_count(&bcx.tcx(), count_expr)
         }
         _ => bcx.tcx().sess.span_bug(content_expr.span,
                                      "Unexpected evec content")