---

yaml
---
r: 105175
b: refs/heads/snap-stage3
c: 7febdb7
h: refs/heads/master
i:
  105173: eb63f3a
  105171: 1df1ca8
  105167: 9c9c858
v: v3

Author: emberian

[refs]

@@ -1,7 +1,7 @@
 ---
 refs/heads/master: 62f1d68439dcfd509eaca29887afa97f22938373
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
-refs/heads/snap-stage3: e560db7dab16ffe77d32a7ca14376fd54d9c2dfc
+refs/heads/snap-stage3: 7febdb7b15681a6a70da191128a9552f35ed5644
 refs/heads/try: db814977d07bd798feb24f6b74c00800ef458a13
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b

branches/snap-stage3/src/librustc/middle/trans/_match.rs

@@ -256,23 +256,43 @@ enum Opt {
     vec_len(/* length */ uint, VecLenOpt, /*range of matches*/(uint, uint))
 }
 
-fn lit_to_expr(tcx: &ty::ctxt, a: &Lit) -> @ast::Expr {
-    match *a {
-        ExprLit(existing_a_expr) => existing_a_expr,
-        ConstLit(a_const) => const_eval::lookup_const_by_id(tcx, a_const).unwrap(),
-        UnitLikeStructLit(_) => fail!("lit_to_expr: unexpected struct lit"),
-    }
-}
-
 fn opt_eq(tcx: &ty::ctxt, a: &Opt, b: &Opt) -> bool {
     match (a, b) {
-        (&lit(UnitLikeStructLit(a)), &lit(UnitLikeStructLit(b))) => a == b,
         (&lit(a), &lit(b)) => {
-            let a_expr = lit_to_expr(tcx, &a);
-            let b_expr = lit_to_expr(tcx, &b);
-            match const_eval::compare_lit_exprs(tcx, a_expr, b_expr) {
-                Some(val1) => val1 == 0,
-                None => fail!("compare_list_exprs: type mismatch"),
+            match (a, b) {
+                (UnitLikeStructLit(a), UnitLikeStructLit(b)) => a == b,
+                _ => {
+                    let a_expr;
+                    match a {
+                        ExprLit(existing_a_expr) => a_expr = existing_a_expr,
+                            ConstLit(a_const) => {
+                                let e = const_eval::lookup_const_by_id(tcx, a_const);
+                                a_expr = e.unwrap();
+                            }
+                        UnitLikeStructLit(_) => {
+                            fail!("UnitLikeStructLit should have been handled \
+                                    above")
+                        }
+                    }
+
+                    let b_expr;
+                    match b {
+                        ExprLit(existing_b_expr) => b_expr = existing_b_expr,
+                            ConstLit(b_const) => {
+                                let e = const_eval::lookup_const_by_id(tcx, b_const);
+                                b_expr = e.unwrap();
+                            }
+                        UnitLikeStructLit(_) => {
+                            fail!("UnitLikeStructLit should have been handled \
+                                    above")
+                        }
+                    }
+
+                    match const_eval::compare_lit_exprs(tcx, a_expr, b_expr) {
+                        Some(val1) => val1 == 0,
+                        None => fail!("compare_list_exprs: type mismatch"),
+                    }
+                }
             }
         }
         (&range(a1, a2), &range(b1, b2)) => {
@@ -290,42 +310,6 @@ fn opt_eq(tcx: &ty::ctxt, a: &Opt, b: &Opt) -> bool {
     }
 }
 
-fn opt_overlap(tcx: &ty::ctxt, a: &Opt, b: &Opt) -> bool {
-    match (a, b) {
-        (&lit(a), &lit(b)) => {
-            let a_expr = lit_to_expr(tcx, &a);
-            let b_expr = lit_to_expr(tcx, &b);
-            match const_eval::compare_lit_exprs(tcx, a_expr, b_expr) {
-                Some(val1) => val1 == 0,
-                None => fail!("opt_overlap: type mismatch"),
-            }
-        }
-
-        (&range(a1, a2), &range(b1, b2)) => {
-            let m1 = const_eval::compare_lit_exprs(tcx, a1, b2);
-            let m2 = const_eval::compare_lit_exprs(tcx, b1, a2);
-            match (m1, m2) {
-                // two ranges [a1, a2] and [b1, b2] overlap iff:
-                //      a1 <= b2 && b1 <= a2
-                (Some(val1), Some(val2)) => (val1 <= 0 && val2 <= 0),
-                _ => fail!("opt_overlap: type mismatch"),
-            }
-        }
-
-        (&range(a1, a2), &lit(b)) | (&lit(b), &range(a1, a2)) => {
-            let b_expr = lit_to_expr(tcx, &b);
-            let m1 = const_eval::compare_lit_exprs(tcx, a1, b_expr);
-            let m2 = const_eval::compare_lit_exprs(tcx, a2, b_expr);
-            match (m1, m2) {
-                // b is in range [a1, a2] iff a1 <= b and b <= a2
-                (Some(val1), Some(val2)) => (val1 <= 0 && 0 <= val2),
-                _ => fail!("opt_overlap: type mismatch"),
-            }
-        }
-        _ => fail!("opt_overlap: expect lit or range")
-    }
-}
-
 pub enum opt_result<'a> {
     single_result(Result<'a>),
     lower_bound(Result<'a>),
@@ -506,7 +490,7 @@ fn assert_is_binding_or_wild(bcx: &Block, p: @ast::Pat) {
     }
 }
 
-type enter_pat<'a> = 'a |@ast::Pat| -> Option<Vec<@ast::Pat>>;
+type enter_pat<'a> = 'a |@ast::Pat| -> Option<Vec<@ast::Pat> >;
 
 fn enter_match<'r,'b>(
                bcx: &'b Block<'b>,
@@ -648,30 +632,16 @@ fn enter_opt<'r,'b>(
     let tcx = bcx.tcx();
     let dummy = @ast::Pat {id: 0, node: ast::PatWild, span: DUMMY_SP};
     let mut i = 0;
-    // By the virtue of fact that we are in `trans` already, `enter_opt` is able
-    // to prune sub-match tree aggressively based on exact equality. But when it
-    // comes to literal or range, that strategy may lead to wrong result if there
-    // are guard function or multiple patterns inside tuple; in that case, pruning
-    // based on the overlap of patterns is required.
-    //
-    // Ideally, when constructing the sub-match tree for certain arm, only those
-    // arms beneath it matter. But that isn't how algorithm works right now and
-    // all other arms are taken into consideration when computing `guarded` below.
-    // That is ok since each round of `compile_submatch` guarantees to trim one
-    // "column" of arm patterns and the algorithm will converge.
-    let guarded = m.iter().any(|x| x.data.arm.guard.is_some());
-    let multi_pats = m.len() > 0 && m[0].pats.len() > 1;
     enter_match(bcx, tcx.def_map, m, col, val, |p| {
         let answer = match p.node {
             ast::PatEnum(..) |
             ast::PatIdent(_, _, None) if pat_is_const(tcx.def_map, p) => {
                 let const_def = tcx.def_map.borrow().get_copy(&p.id);
                 let const_def_id = ast_util::def_id_of_def(const_def);
-                let konst = lit(ConstLit(const_def_id));
-                match guarded || multi_pats {
-                    false if opt_eq(tcx, &konst, opt) => Some(Vec::new()),
-                    true if opt_overlap(tcx, &konst, opt) => Some(Vec::new()),
-                    _ => None,
+                if opt_eq(tcx, &lit(ConstLit(const_def_id)), opt) {
+                    Some(Vec::new())
+                } else {
+                    None
                 }
             }
             ast::PatEnum(_, ref subpats) => {
@@ -696,20 +666,10 @@ fn enter_opt<'r,'b>(
                 }
             }
             ast::PatLit(l) => {
-                let lit_expr = lit(ExprLit(l));
-                match guarded || multi_pats {
-                    false if opt_eq(tcx, &lit_expr, opt) => Some(Vec::new()),
-                    true if opt_overlap(tcx, &lit_expr, opt) => Some(Vec::new()),
-                    _ => None,
-                }
+                if opt_eq(tcx, &lit(ExprLit(l)), opt) {Some(Vec::new())} else {None}
             }
             ast::PatRange(l1, l2) => {
-                let rng = range(l1, l2);
-                match guarded || multi_pats {
-                    false if opt_eq(tcx, &rng, opt) => Some(Vec::new()),
-                    true if opt_overlap(tcx, &rng, opt) => Some(Vec::new()),
-                    _ => None,
-                }
+                if opt_eq(tcx, &range(l1, l2), opt) {Some(Vec::new())} else {None}
             }
             ast::PatStruct(_, ref field_pats, _) => {
                 if opt_eq(tcx, &variant_opt(bcx, p.id), opt) {

branches/snap-stage3/src/librustc/middle/trans/base.rs

@@ -246,6 +246,7 @@ fn get_extern_rust_fn(ccx: &CrateContext, inputs: &[ty::t], output: ty::t,
 pub fn decl_rust_fn(ccx: &CrateContext, has_env: bool,
                     inputs: &[ty::t], output: ty::t,
                     name: &str) -> ValueRef {
+    use middle::ty::{FreeRegion, BrAnon, ReFree, ReLateBound};
     let llfty = type_of_rust_fn(ccx, has_env, inputs, output);
     let llfn = decl_cdecl_fn(ccx.llmod, name, llfty, output);
 
@@ -265,7 +266,17 @@ pub fn decl_rust_fn(ccx: &CrateContext, has_env: bool,
                 unsafe {
                     llvm::LLVMAddAttribute(llarg, lib::llvm::NoAliasAttribute as c_uint);
                 }
-            }
+            },
+            // When a reference in an argument has no named lifetime, it's
+            // impossible for that reference to escape this function(ie, be
+            // returned).
+            ty::ty_rptr(ReFree(FreeRegion { scope_id: _, bound_region: BrAnon(_) }), _) |
+                ty::ty_rptr(ReLateBound(_, BrAnon(_)), _) => {
+                debug!("marking argument of {} as nocapture because of anonymous lifetime", name);
+                unsafe {
+                    llvm::LLVMAddAttribute(llarg, lib::llvm::NoCaptureAttribute as c_uint);
+                }
+            },
             _ => {
                 // For non-immediate arguments the callee gets its own copy of
                 // the value on the stack, so there are no aliases

branches/snap-stage3/src/librustc/middle/trans/callee.rs

@@ -20,7 +20,7 @@ use std::slice;
 
 use back::abi;
 use driver::session;
-use lib::llvm::{ValueRef, NoAliasAttribute, StructRetAttribute};
+use lib::llvm::{ValueRef, NoAliasAttribute, StructRetAttribute, NoCaptureAttribute};
 use lib::llvm::llvm;
 use metadata::csearch;
 use middle::trans::base;
@@ -661,9 +661,15 @@ pub fn trans_call_inner<'a>(
             llargs.push(opt_llretslot.unwrap());
         }
 
+        // start at 1, because index 0 is the return value of the llvm func
+        let mut first_arg_offset = 1;
+
         // Push the environment (or a trait object's self).
         match (llenv, llself) {
-            (Some(llenv), None) => llargs.push(llenv),
+            (Some(llenv), None) => {
+                first_arg_offset += 1;
+                llargs.push(llenv)
+            },
             (None, Some(llself)) => llargs.push(llself),
             _ => {}
         }
@@ -682,6 +688,11 @@ pub fn trans_call_inner<'a>(
         let mut attrs = Vec::new();
         if type_of::return_uses_outptr(ccx, ret_ty) {
             attrs.push((1, StructRetAttribute));
+            // The outptr can be noalias and nocapture because it's entirely
+            // invisible to the program.
+            attrs.push((1, NoAliasAttribute));
+            attrs.push((1, NoCaptureAttribute));
+            first_arg_offset += 1;
         }
 
         // The `noalias` attribute on the return value is useful to a
@@ -695,6 +706,30 @@ pub fn trans_call_inner<'a>(
             _ => {}
         }
 
+        debug!("trans_callee_inner: first_arg_offset={}", first_arg_offset);
+
+        for (idx, &t) in ty::ty_fn_args(callee_ty).iter().enumerate().map(|(i, v)| (i+first_arg_offset, v)) {
+            use middle::ty::{FreeRegion, BrAnon, ReFree, ReLateBound};
+            if !type_is_immediate(ccx, t) {
+                // if it's not immediate, we have a program-invisible pointer,
+                // which it can't possibly capture
+                attrs.push((idx, NoCaptureAttribute));
+                debug!("trans_callee_inner: argument {} nocapture because it's non-immediate", idx);
+                continue;
+            }
+
+            let t_ = ty::get(t);
+            match t_.sty {
+                ty::ty_rptr(ReFree(FreeRegion { scope_id: _, bound_region: BrAnon(_) }), _) |
+                    ty::ty_rptr(ReLateBound(_, BrAnon(_)), _) => {
+
+                    debug!("trans_callee_inner: argument {} nocapture because of anonymous lifetime", idx);
+                    attrs.push((idx, NoCaptureAttribute));
+                },
+                _ => { }
+            }
+        }
+
         // Invoke the actual rust fn and update bcx/llresult.
         let (llret, b) = base::invoke(bcx,
                                       llfn,

branches/snap-stage3/src/libsyntax/parse/parser.rs

@@ -111,6 +111,13 @@ pub enum PathParsingMode {
     LifetimeAndTypesAndBounds,
 }
 
+/// A pair of a path segment and group of type parameter bounds. (See `ast.rs`
+/// for the definition of a path segment.)
+struct PathSegmentAndBoundSet {
+    segment: ast::PathSegment,
+    bound_set: Option<OwnedSlice<TyParamBound>>,
+}
+
 /// A path paired with optional type bounds.
 pub struct PathAndBounds {
     path: ast::Path,
@@ -1507,14 +1514,24 @@ impl<'a> Parser<'a> {
             // First, parse an identifier.
             let identifier = self.parse_ident();
 
+            // Next, parse a colon and bounded type parameters, if applicable.
+            let bound_set = if mode == LifetimeAndTypesAndBounds {
+                self.parse_optional_ty_param_bounds()
+            } else {
+                None
+            };
+
             // Parse the '::' before type parameters if it's required. If
             // it is required and wasn't present, then we're done.
             if mode == LifetimeAndTypesWithColons &&
                     !self.eat(&token::MOD_SEP) {
-                segments.push(ast::PathSegment {
-                    identifier: identifier,
-                    lifetimes: Vec::new(),
-                    types: OwnedSlice::empty(),
+                segments.push(PathSegmentAndBoundSet {
+                    segment: ast::PathSegment {
+                        identifier: identifier,
+                        lifetimes: Vec::new(),
+                        types: OwnedSlice::empty(),
+                    },
+                    bound_set: bound_set
                 });
                 break
             }
@@ -1531,10 +1548,13 @@ impl<'a> Parser<'a> {
             };
 
             // Assemble and push the result.
-            segments.push(ast::PathSegment {
-                identifier: identifier,
-                lifetimes: lifetimes,
-                types: types,
+            segments.push(PathSegmentAndBoundSet {
+                segment: ast::PathSegment {
+                    identifier: identifier,
+                    lifetimes: lifetimes,
+                    types: types,
+                },
+                bound_set: bound_set
             });
 
             // We're done if we don't see a '::', unless the mode required
@@ -1547,25 +1567,42 @@ impl<'a> Parser<'a> {
             }
         }
 
-        // Next, parse a colon and bounded type parameters, if applicable.
-        let bounds = if mode == LifetimeAndTypesAndBounds {
-            self.parse_optional_ty_param_bounds()
-        } else {
-            None
-        };
-
         // Assemble the span.
         let span = mk_sp(lo, self.last_span.hi);
 
+        // Assemble the path segments.
+        let mut path_segments = Vec::new();
+        let mut bounds = None;
+        let last_segment_index = segments.len() - 1;
+        for (i, segment_and_bounds) in segments.move_iter().enumerate() {
+            let PathSegmentAndBoundSet {
+                segment: segment,
+                bound_set: bound_set
+            } = segment_and_bounds;
+            path_segments.push(segment);
+
+            if bound_set.is_some() {
+                if i != last_segment_index {
+                    self.span_err(span,
+                                  "type parameter bounds are allowed only \
+                                   before the last segment in a path")
+                }
+
+                bounds = bound_set
+            }
+        }
+
         // Assemble the result.
-        PathAndBounds {
+        let path_and_bounds = PathAndBounds {
             path: ast::Path {
                 span: span,
                 global: is_global,
-                segments: segments,
+                segments: path_segments,
             },
             bounds: bounds,
-        }
+        };
+
+        path_and_bounds
     }
 
     /// parses 0 or 1 lifetime