Auto merge of #40224 - nikomatsakis:issue-39808, r=eddyb

change the strategy for diverging types

The new strategy is as follows. First, the `!` type is assigned
in two cases:

- a block with a diverging statement and no tail expression (e.g.,
  `{return;}`);
- any expression with the type `!` is considered diverging.

Second, we track when we are in a diverging state, and we permit a value
of any type to be coerced **into** `!` if the expression that produced
it is diverging. This means that `fn foo() -> ! { panic!(); 22 }`
type-checks, even though the block has a type of `usize`.

Finally, coercions **from** the `!` type to any other are always
permitted.

Fixes #39808.
Fixes #39984.

117 files changed, 1366 insertions, 1997 deletions

diff --git a/src/test/compile-fail/coerce-to-bang-cast.rs b/src/test/compile-fail/coerce-to-bang-cast.rs
new file mode 100644
index 00000000000..57d2192e635
--- /dev/null
+++ b/src/test/compile-fail/coerce-to-bang-cast.rs
@@ -0,0 +1,23 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(never_type)]
+
+fn foo(x: usize, y: !, z: usize) { }
+
+fn cast_a() {
+    let y = {return; 22} as !;
+}
+
+fn cast_b() {
+    let y = 22 as !; //~ ERROR non-scalar cast
+}
+
+fn main() { }
diff --git a/src/test/compile-fail/coerce-to-bang.rs b/src/test/compile-fail/coerce-to-bang.rs
new file mode 100644
index 00000000000..870665bb49e
--- /dev/null
+++ b/src/test/compile-fail/coerce-to-bang.rs
@@ -0,0 +1,90 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(never_type)]
+
+fn foo(x: usize, y: !, z: usize) { }
+
+fn call_foo_a() {
+    // FIXME(#40800) -- accepted beacuse divergence happens **before**
+    // the coercion to `!`, but within same expression. Not clear that
+    // these are the rules we want.
+    foo(return, 22, 44);
+}
+
+fn call_foo_b() {
+    // Divergence happens in the argument itself, definitely ok.
+    foo(22, return, 44);
+}
+
+fn call_foo_c() {
+    // This test fails because the divergence happens **after** the
+    // coercion to `!`:
+    foo(22, 44, return); //~ ERROR mismatched types
+}
+
+fn call_foo_d() {
+    // This test passes because `a` has type `!`:
+    let a: ! = return;
+    let b = 22;
+    let c = 44;
+    foo(a, b, c); // ... and hence a reference to `a` is expected to diverge.
+}
+
+fn call_foo_e() {
+    // This test probably could pass but we don't *know* that `a`
+    // has type `!` so we don't let it work.
+    let a = return;
+    let b = 22;
+    let c = 44;
+    foo(a, b, c); //~ ERROR mismatched types
+}
+
+fn call_foo_f() {
+    // This fn fails because `a` has type `usize`, and hence a
+    // reference to is it **not** considered to diverge.
+    let a: usize = return;
+    let b = 22;
+    let c = 44;
+    foo(a, b, c); //~ ERROR mismatched types
+}
+
+fn array_a() {
+    // Accepted: return is coerced to `!` just fine, and then `22` can be
+    // because we already diverged.
+    let x: [!; 2] = [return, 22];
+}
+
+fn array_b() {
+    // Error: divergence has not yet occurred.
+    let x: [!; 2] = [22, return]; //~ ERROR mismatched types
+}
+
+fn tuple_a() {
+    // No divergence at all.
+    let x: (usize, !, usize) = (22, 44, 66); //~ ERROR mismatched types
+}
+
+fn tuple_b() {
+    // Divergence happens before coercion: OK
+    let x: (usize, !, usize) = (return, 44, 66);
+}
+
+fn tuple_c() {
+    // Divergence happens before coercion: OK
+    let x: (usize, !, usize) = (22, return, 66);
+}
+
+fn tuple_d() {
+    // Error: divergence happens too late
+    let x: (usize, !, usize) = (22, 44, return); //~ ERROR mismatched types
+}
+
+fn main() { }
diff --git a/src/test/compile-fail/defaulted-unit-warning.rs b/src/test/compile-fail/defaulted-unit-warning.rs
index 5213a189714..ed6263d0fdb 100644
--- a/src/test/compile-fail/defaulted-unit-warning.rs
+++ b/src/test/compile-fail/defaulted-unit-warning.rs
@@ -22,16 +22,6 @@ impl Deserialize for () {
     }
 }
 
-fn doit() -> Result<(), String> {
-    let _ = match Deserialize::deserialize() {
-        //~^ ERROR code relies on type
-        //~| WARNING previously accepted
-        Ok(x) => x,
-        Err(e) => return Err(e),
-    };
-    Ok(())
-}
-
 trait ImplementedForUnitButNotNever {}
 
 impl ImplementedForUnitButNotNever for () {}
@@ -46,6 +36,6 @@ fn smeg() {
 }
 
 fn main() {
-    let _ = doit();
+    smeg();
 }
 
diff --git a/src/test/run-make/graphviz-flowgraph/f23.rs b/src/test/compile-fail/diverging-tuple-parts-39485.rs
index 52341a3fbd4..eedad08ab55 100644
--- a/src/test/run-make/graphviz-flowgraph/f23.rs
+++ b/src/test/compile-fail/diverging-tuple-parts-39485.rs
@@ -8,24 +8,18 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#[allow(unreachable_code)]
-pub fn expr_while_23() {
-    let mut x = 23;
-    let mut y = 23;
-    let mut z = 23;
+// After #39485, this test used to pass, but that change was reverted
+// due to numerous inference failures like #39808, so it now fails
+// again. #39485 made it so that diverging types never propagate
+// upward; but we now do propagate such types upward in many more
+// cases.
 
-    while x > 0 {
-        x -= 1;
-
-        while y > 0 {
-            y -= 1;
-
-            while z > 0 { z -= 1; }
+fn g() {
+    &panic!() //~ ERROR mismatched types
+}
 
-            if x > 10 {
-                return;
-                "unreachable";
-            }
-        }
-    }
+fn f() -> isize {
+    (return 1, return 2) //~ ERROR mismatched types
 }
+
+fn main() {}
diff --git a/src/test/compile-fail/index-bot.rs b/src/test/compile-fail/index-bot.rs
index 70c362303ae..05b04723300 100644
--- a/src/test/compile-fail/index-bot.rs
+++ b/src/test/compile-fail/index-bot.rs
@@ -9,5 +9,5 @@
 // except according to those terms.
 
 fn main() {
-    (return)[0]; //~ ERROR the type of this value must be known in this context
+    (return)[0]; //~ ERROR cannot index a value of type `!`
 }
diff --git a/src/test/compile-fail/issue-10176.rs b/src/test/compile-fail/issue-10176.rs
index 434b795ff31..c968844ae21 100644
--- a/src/test/compile-fail/issue-10176.rs
+++ b/src/test/compile-fail/issue-10176.rs
@@ -12,7 +12,7 @@ fn f() -> isize {
     (return 1, return 2)
 //~^ ERROR mismatched types
 //~| expected type `isize`
-//~| found type `(_, _)`
+//~| found type `(!, !)`
 //~| expected isize, found tuple
 }
 
diff --git a/src/test/compile-fail/issue-13847.rs b/src/test/compile-fail/issue-13847.rs
index aa823d9a70e..0314f109a7c 100644
--- a/src/test/compile-fail/issue-13847.rs
+++ b/src/test/compile-fail/issue-13847.rs
@@ -9,5 +9,5 @@
 // except according to those terms.
 
 fn main() {
-    return.is_failure //~ ERROR the type of this value must be known in this context
+    return.is_failure //~ ERROR no field `is_failure` on type `!`
 }
diff --git a/src/test/compile-fail/issue-15207.rs b/src/test/compile-fail/issue-15207.rs
index 61877775269..70da8cf4169 100644
--- a/src/test/compile-fail/issue-15207.rs
+++ b/src/test/compile-fail/issue-15207.rs
@@ -10,7 +10,7 @@
 
 fn main() {
     loop {
-        break.push(1) //~ ERROR the type of this value must be known in this context
+        break.push(1) //~ ERROR no method named `push` found for type `!`
         ;
     }
 }
diff --git a/src/test/compile-fail/issue-17373.rs b/src/test/compile-fail/issue-17373.rs
index 6895893adc4..f6e6a8a0852 100644
--- a/src/test/compile-fail/issue-17373.rs
+++ b/src/test/compile-fail/issue-17373.rs
@@ -9,6 +9,6 @@
 // except according to those terms.
 
 fn main() {
-    *return //~ ERROR the type of this value must be known in this context
+    *return //~ ERROR type `!` cannot be dereferenced
     ;
 }
diff --git a/src/test/compile-fail/issue-18532.rs b/src/test/compile-fail/issue-18532.rs
index 94eab97c42a..2be5fdcac4e 100644
--- a/src/test/compile-fail/issue-18532.rs
+++ b/src/test/compile-fail/issue-18532.rs
@@ -13,6 +13,5 @@
 // into it.
 
 fn main() {
-    (return)((),());
-    //~^ ERROR the type of this value must be known
+    (return)((),()); //~ ERROR expected function, found `!`
 }
diff --git a/src/test/compile-fail/issue-2149.rs b/src/test/compile-fail/issue-2149.rs
index 9143a226a24..256c5d8e6f7 100644
--- a/src/test/compile-fail/issue-2149.rs
+++ b/src/test/compile-fail/issue-2149.rs
@@ -21,5 +21,5 @@ impl<A> vec_monad<A> for Vec<A> {
 }
 fn main() {
     ["hi"].bind(|x| [x] );
-    //~^ ERROR no method named `bind` found for type `[&'static str; 1]` in the current scope
+    //~^ ERROR no method named `bind` found for type `[&str; 1]` in the current scope
 }
diff --git a/src/test/compile-fail/issue-27042.rs b/src/test/compile-fail/issue-27042.rs
index f31389f1337..23afa4b6296 100644
--- a/src/test/compile-fail/issue-27042.rs
+++ b/src/test/compile-fail/issue-27042.rs
@@ -12,14 +12,14 @@
 
 fn main() {
     let _: i32 =
-        'a: //~ ERROR mismatched types
-        loop { break };
+        'a: // in this case, the citation is just the `break`:
+        loop { break }; //~ ERROR mismatched types
     let _: i32 =
         'b: //~ ERROR mismatched types
-        while true { break };
+        while true { break }; // but here we cite the whole loop
     let _: i32 =
         'c: //~ ERROR mismatched types
-        for _ in None { break };
+        for _ in None { break }; // but here we cite the whole loop
     let _: i32 =
         'd: //~ ERROR mismatched types
         while let Some(_) = None { break };
diff --git a/src/test/compile-fail/loop-break-value.rs b/src/test/compile-fail/loop-break-value.rs
index d4f29597486..a4143218992 100644
--- a/src/test/compile-fail/loop-break-value.rs
+++ b/src/test/compile-fail/loop-break-value.rs
@@ -40,37 +40,40 @@ fn main() {
         loop {
             break 'while_loop 123;
             //~^ ERROR `break` with value from a `while` loop
-            //~| ERROR mismatched types
             break 456;
             break 789;
         };
     }
 
-    'while_let_loop: while let Some(_) = Some(()) {
+    while let Some(_) = Some(()) {
         if break () { //~ ERROR `break` with value from a `while let` loop
-            break;
-            break None;
-            //~^ ERROR `break` with value from a `while let` loop
-            //~| ERROR mismatched types
         }
+    }
+
+    while let Some(_) = Some(()) {
+        break None;
+        //~^ ERROR `break` with value from a `while let` loop
+    }
+
+    'while_let_loop: while let Some(_) = Some(()) {
         loop {
             break 'while_let_loop "nope";
             //~^ ERROR `break` with value from a `while let` loop
-            //~| ERROR mismatched types
             break 33;
         };
     }
 
-    'for_loop: for _ in &[1,2,3] {
+    for _ in &[1,2,3] {
         break (); //~ ERROR `break` with value from a `for` loop
         break [()];
         //~^ ERROR `break` with value from a `for` loop
-        //~| ERROR mismatched types
+    }
+
+    'for_loop: for _ in &[1,2,3] {
         loop {
             break Some(3);
             break 'for_loop Some(17);
             //~^ ERROR `break` with value from a `for` loop
-            //~| ERROR mismatched types
         };
     }
 
diff --git a/src/test/run-make/graphviz-flowgraph/f01.rs b/src/test/compile-fail/match-no-arms-unreachable-after.rs
index 231aab69e50..db08f5e5e66 100644
--- a/src/test/run-make/graphviz-flowgraph/f01.rs
+++ b/src/test/compile-fail/match-no-arms-unreachable-after.rs
@@ -1,4 +1,4 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,6 +8,15 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-pub fn lit_1() {
-    1;
+#![allow(warnings)]
+#![deny(unreachable_code)]
+
+enum Void { }
+
+fn foo(v: Void) {
+    match v { }
+    let x = 2; //~ ERROR unreachable
+}
+
+fn main() {
 }
diff --git a/src/test/run-make/graphviz-flowgraph/f07.rs b/src/test/compile-fail/match-unreachable-warning-with-diverging-discrim.rs
index f36b8d0abc7..aae0f3135d8 100644
--- a/src/test/run-make/graphviz-flowgraph/f07.rs
+++ b/src/test/compile-fail/match-unreachable-warning-with-diverging-discrim.rs
@@ -1,4 +1,4 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,10 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(slice_patterns)]
+#![allow(unused_parens)]
+#![deny(unreachable_code)]
 
-pub fn pat_vec_7() {
-    match [7, 77, 777, 7777] {
-        [x, y, ..] => x + y
-    };
+fn main() {
+    match (return) { } //~ ERROR unreachable expression
 }
diff --git a/src/test/compile-fail/match-unresolved-one-arm.rs b/src/test/compile-fail/match-unresolved-one-arm.rs
new file mode 100644
index 00000000000..ea0f8db99e8
--- /dev/null
+++ b/src/test/compile-fail/match-unresolved-one-arm.rs
@@ -0,0 +1,17 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn foo<T>() -> T { panic!("Rocks for my pillow") }
+
+fn main() {
+    let x = match () { //~ ERROR type annotations needed
+        () => foo() // T here should be unresolved
+    };
+}
diff --git a/src/test/compile-fail/never-assign-dead-code.rs b/src/test/compile-fail/never-assign-dead-code.rs
index 57e0bca6a6d..d8752e1c050 100644
--- a/src/test/compile-fail/never-assign-dead-code.rs
+++ b/src/test/compile-fail/never-assign-dead-code.rs
@@ -16,5 +16,6 @@
 fn main() {
     let x: ! = panic!("aah"); //~ ERROR unused
     drop(x); //~ ERROR unreachable
+    //~^ ERROR unreachable
 }
 
diff --git a/src/test/compile-fail/never-assign-wrong-type.rs b/src/test/compile-fail/never-assign-wrong-type.rs
index 53d96aaf4fe..d854e6eb203 100644
--- a/src/test/compile-fail/never-assign-wrong-type.rs
+++ b/src/test/compile-fail/never-assign-wrong-type.rs
@@ -11,6 +11,7 @@
 // Test that we can't use another type in place of !
 
 #![feature(never_type)]
+#![deny(warnings)]
 
 fn main() {
     let x: ! = "hello"; //~ ERROR mismatched types
diff --git a/src/test/compile-fail/never-fallback.rs b/src/test/compile-fail/never-fallback.rs
deleted file mode 100644
index a43b1a45fe9..00000000000
--- a/src/test/compile-fail/never-fallback.rs
+++ /dev/null
@@ -1,41 +0,0 @@
-// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-// Test that diverging types default to ! when feature(never_type) is enabled. This test is the
-// same as run-pass/unit-fallback.rs except that ! is enabled.
-
-#![feature(never_type)]
-
-trait Balls: Sized {
-    fn smeg() -> Result<Self, ()>;
-}
-
-impl Balls for () {
-    fn smeg() -> Result<(), ()> { Ok(()) }
-}
-
-struct Flah;
-
-impl Flah {
-    fn flah<T: Balls>(&self) -> Result<T, ()> {
-        T::smeg()
-    }
-}
-
-fn doit() -> Result<(), ()> {
-    // The type of _ is unconstrained here and should default to !
-    let _ = try!(Flah.flah()); //~ ERROR the trait bound
-    Ok(())
-}
-
-fn main() {
-    let _ = doit();
-}
-
diff --git a/src/test/compile-fail/region-invariant-static-error-reporting.rs b/src/test/compile-fail/region-invariant-static-error-reporting.rs
index ac0167e08bd..d25674a74b1 100644
--- a/src/test/compile-fail/region-invariant-static-error-reporting.rs
+++ b/src/test/compile-fail/region-invariant-static-error-reporting.rs
@@ -16,9 +16,6 @@
 // error-pattern:cannot infer
 // error-pattern:cannot outlive the lifetime 'a
 // error-pattern:must be valid for the static lifetime
-// error-pattern:cannot infer
-// error-pattern:cannot outlive the lifetime 'a
-// error-pattern:must be valid for the static lifetime
 
 struct Invariant<'a>(Option<&'a mut &'a mut ()>);
 
diff --git a/src/test/compile-fail/regions-bounds.rs b/src/test/compile-fail/regions-bounds.rs
index 64dbf27b78e..5ce80be98d9 100644
--- a/src/test/compile-fail/regions-bounds.rs
+++ b/src/test/compile-fail/regions-bounds.rs
@@ -16,17 +16,11 @@ struct an_enum<'a>(&'a isize);
 struct a_class<'a> { x:&'a isize }
 
 fn a_fn1<'a,'b>(e: an_enum<'a>) -> an_enum<'b> {
-    return e; //~  ERROR mismatched types
-              //~| expected type `an_enum<'b>`
-              //~| found type `an_enum<'a>`
-              //~| lifetime mismatch
+    return e; //~ ERROR mismatched types
 }
 
 fn a_fn3<'a,'b>(e: a_class<'a>) -> a_class<'b> {
-    return e; //~  ERROR mismatched types
-              //~| expected type `a_class<'b>`
-              //~| found type `a_class<'a>`
-              //~| lifetime mismatch
+    return e; //~ ERROR mismatched types
 }
 
 fn main() { }
diff --git a/src/test/run-make/graphviz-flowgraph/Makefile b/src/test/run-make/graphviz-flowgraph/Makefile
deleted file mode 100644
index 5740a36359c..00000000000
--- a/src/test/run-make/graphviz-flowgraph/Makefile
+++ /dev/null
@@ -1,38 +0,0 @@
--include ../tools.mk
-
-FILES=f00.rs f01.rs f02.rs f03.rs f04.rs f05.rs f06.rs f07.rs \
-      f08.rs f09.rs f10.rs f11.rs f12.rs f13.rs f14.rs f15.rs \
-      f16.rs f17.rs f18.rs f19.rs f20.rs f21.rs f22.rs f23.rs \
-      f24.rs f25.rs
-
-
-# all: $(patsubst %.rs,$(TMPDIR)/%.dot,$(FILES)) $(patsubst %.rs,$(TMPDIR)/%.pp,$(FILES))
-all: $(patsubst %.rs,$(TMPDIR)/%.check,$(FILES))
-
-
-RUSTC_LIB=$(RUSTC) --crate-type=lib
-
-define FIND_LAST_BLOCK
-LASTBLOCKNUM_$(1) := $(shell $(RUSTC_LIB) -Z unstable-options --pretty=expanded,identified $(1) \
-			 | grep block
-			 | tail -1
-			 | sed -e 's@.*/\* block \([0-9]*\) \*/.*@\1@')
-endef
-
-ifeq ($(findstring rustc,$(RUSTC)),)
-$(error Must set RUSTC)
-endif
-
-$(TMPDIR)/%.pp: %.rs
-	$(RUSTC_LIB) --pretty=expanded,identified $< -o $@
-
-$(TMPDIR)/%.dot: %.rs
-	$(eval $(call FIND_LAST_BLOCK,$<))
-	$(RUSTC_LIB) -Z unstable-options --unpretty flowgraph,unlabelled=$(LASTBLOCKNUM_$<) $< -o $@.tmp
-	cat $@.tmp | sed -e 's@ (id=[0-9]*)@@g' \
-                         -e 's@\[label=""\]@@' \
-                         -e 's@digraph [a-zA-Z0-9_]* @digraph block @' \
-                     > $@
-
-$(TMPDIR)/%.check: %.rs $(TMPDIR)/%.dot
-	diff -u $(patsubst %.rs,$(TMPDIR)/%.dot,$<) $(patsubst %.rs,%.dot-expected.dot,$<)
diff --git a/src/test/run-make/graphviz-flowgraph/f00.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f00.dot-expected.dot
deleted file mode 100644
index 8ea8370ab23..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f00.dot-expected.dot
+++ /dev/null
@@ -1,9 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="block { }"];
-    N3[label="expr { }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f01.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f01.dot-expected.dot
deleted file mode 100644
index 5982fbea769..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f01.dot-expected.dot
+++ /dev/null
@@ -1,13 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 1"];
-    N3[label="stmt 1;"];
-    N4[label="block { 1; }"];
-    N5[label="expr { 1; }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f02.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f02.dot-expected.dot
deleted file mode 100644
index 1639785bd68..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f02.dot-expected.dot
+++ /dev/null
@@ -1,13 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="local _x"];
-    N3[label="stmt let _x: isize;"];
-    N4[label="block { let _x: isize; }"];
-    N5[label="expr { let _x: isize; }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f03.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f03.dot-expected.dot
deleted file mode 100644
index b0ae00d8167..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f03.dot-expected.dot
+++ /dev/null
@@ -1,17 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 3"];
-    N3[label="expr 4"];
-    N4[label="expr 3 + 4"];
-    N5[label="stmt 3 + 4;"];
-    N6[label="block { 3 + 4; }"];
-    N7[label="expr { 3 + 4; }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f03.rs b/src/test/run-make/graphviz-flowgraph/f03.rs
deleted file mode 100644
index 2dd71b623c2..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f03.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-pub fn expr_add_3() {
-    3 + 4;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f04.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f04.dot-expected.dot
deleted file mode 100644
index 41ace15a4c6..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f04.dot-expected.dot
+++ /dev/null
@@ -1,15 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 4"];
-    N3[label="local _x"];
-    N4[label="stmt let _x = 4;"];
-    N5[label="block { let _x = 4; }"];
-    N6[label="expr { let _x = 4; }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f04.rs b/src/test/run-make/graphviz-flowgraph/f04.rs
deleted file mode 100644
index 2a0ac8ac9e5..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f04.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-pub fn pat_id_4() {
-    let _x = 4;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f05.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f05.dot-expected.dot
deleted file mode 100644
index 72b8ae71751..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f05.dot-expected.dot
+++ /dev/null
@@ -1,23 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 5"];
-    N3[label="expr 55"];
-    N4[label="expr (5, 55)"];
-    N5[label="local _x"];
-    N6[label="local _y"];
-    N7[label="pat (_x, _y)"];
-    N8[label="stmt let (_x, _y) = (5, 55);"];
-    N9[label="block { let (_x, _y) = (5, 55); }"];
-    N10[label="expr { let (_x, _y) = (5, 55); }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N10;
-    N10 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f05.rs b/src/test/run-make/graphviz-flowgraph/f05.rs
deleted file mode 100644
index 616d822bed0..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f05.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-pub fn pat_tup_5() {
-    let (_x, _y) = (5, 55);
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f06.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f06.dot-expected.dot
deleted file mode 100644
index acba71ef625..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f06.dot-expected.dot
+++ /dev/null
@@ -1,19 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 6"];
-    N3[label="expr S6{val: 6,}"];
-    N4[label="local _x"];
-    N5[label="pat S6 { val: _x }"];
-    N6[label="stmt let S6 { val: _x } = S6{val: 6,};"];
-    N7[label="block { let S6 { val: _x } = S6{val: 6,}; }"];
-    N8[label="expr { let S6 { val: _x } = S6{val: 6,}; }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f06.rs b/src/test/run-make/graphviz-flowgraph/f06.rs
deleted file mode 100644
index 538ef2af898..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f06.rs
+++ /dev/null
@@ -1,14 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-struct S6 { val: isize }
-pub fn pat_struct_6() {
-    let S6 { val: _x } = S6{ val: 6 };
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f07.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f07.dot-expected.dot
deleted file mode 100644
index 251e2b39f14..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f07.dot-expected.dot
+++ /dev/null
@@ -1,39 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 7"];
-    N3[label="expr 77"];
-    N4[label="expr 777"];
-    N5[label="expr 7777"];
-    N6[label="expr [7, 77, 777, 7777]"];
-    N7[label="expr match [7, 77, 777, 7777] { [x, y, ..] => x + y, }"];
-    N8[label="(dummy_node)"];
-    N9[label="local x"];
-    N10[label="local y"];
-    N11[label="pat _"];
-    N12[label="pat [x, y, ..]"];
-    N13[label="expr x"];
-    N14[label="expr y"];
-    N15[label="expr x + y"];
-    N16[label="stmt match [7, 77, 777, 7777] { [x, y, ..] => x + y, };"];
-    N17[label="block { match [7, 77, 777, 7777] { [x, y, ..] => x + y, }; }"];
-    N18[label="expr { match [7, 77, 777, 7777] { [x, y, ..] => x + y, }; }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N9;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N12;
-    N12 -> N8;
-    N8 -> N13;
-    N13 -> N14;
-    N14 -> N15;
-    N15 -> N7;
-    N7 -> N16;
-    N16 -> N17;
-    N17 -> N18;
-    N18 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f08.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f08.dot-expected.dot
deleted file mode 100644
index e2779c9414a..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f08.dot-expected.dot
+++ /dev/null
@@ -1,38 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 8"];
-    N3[label="local x"];
-    N4[label="stmt let x = 8;"];
-    N5[label="local _y"];
-    N6[label="stmt let _y;"];
-    N7[label="expr x"];
-    N8[label="expr 88"];
-    N9[label="expr x > 88"];
-    N10[label="expr 888"];
-    N11[label="expr _y"];
-    N12[label="expr _y = 888"];
-    N13[label="stmt _y = 888;"];
-    N14[label="block { _y = 888; }"];
-    N15[label="expr if x > 88 { _y = 888; }"];
-    N16[label="block { let x = 8; let _y; if x > 88 { _y = 888; } }"];
-    N17[label="expr { let x = 8; let _y; if x > 88 { _y = 888; } }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N12;
-    N12 -> N13;
-    N13 -> N14;
-    N9 -> N15;
-    N14 -> N15;
-    N15 -> N16;
-    N16 -> N17;
-    N17 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f09.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f09.dot-expected.dot
deleted file mode 100644
index 536abde91e8..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f09.dot-expected.dot
+++ /dev/null
@@ -1,54 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 91"];
-    N3[label="local x"];
-    N4[label="stmt let x = 91;"];
-    N5[label="local _y"];
-    N6[label="stmt let _y;"];
-    N7[label="expr x"];
-    N8[label="expr 92"];
-    N9[label="expr x > 92"];
-    N10[label="expr 93"];
-    N11[label="expr _y"];
-    N12[label="expr _y = 93"];
-    N13[label="stmt _y = 93;"];
-    N14[label="block { _y = 93; }"];
-    N15[label="expr 94"];
-    N16[label="expr 95"];
-    N17[label="expr 94 + 95"];
-    N18[label="expr _y"];
-    N19[label="expr _y = 94 + 95"];
-    N20[label="stmt _y = 94 + 95;"];
-    N21[label="block { _y = 94 + 95; }"];
-    N22[label="expr { _y = 94 + 95; }"];
-    N23[label="expr if x > 92 { _y = 93; } else { _y = 94 + 95; }"];
-    N24[label="block { let x = 91; let _y; if x > 92 { _y = 93; } else { _y = 94 + 95; } }"];
-    N25[label="expr { let x = 91; let _y; if x > 92 { _y = 93; } else { _y = 94 + 95; } }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N12;
-    N12 -> N13;
-    N13 -> N14;
-    N9 -> N15;
-    N15 -> N16;
-    N16 -> N17;
-    N17 -> N18;
-    N18 -> N19;
-    N19 -> N20;
-    N20 -> N21;
-    N21 -> N22;
-    N14 -> N23;
-    N22 -> N23;
-    N23 -> N24;
-    N24 -> N25;
-    N25 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f09.rs b/src/test/run-make/graphviz-flowgraph/f09.rs
deleted file mode 100644
index a78ccb8a937..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f09.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-pub fn expr_if_twoarm_9() {
-    let x = 91; let _y;
-    if x > 92 {
-        _y = 93;
-    } else {
-        _y = 94+95;
-    }
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f10.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f10.dot-expected.dot
deleted file mode 100644
index 07b9c744a71..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f10.dot-expected.dot
+++ /dev/null
@@ -1,36 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 10"];
-    N3[label="local mut x"];
-    N4[label="stmt let mut x = 10;"];
-    N5[label="(dummy_node)"];
-    N6[label="expr while x > 0 { x -= 1; }"];
-    N7[label="expr x"];
-    N8[label="expr 0"];
-    N9[label="expr x > 0"];
-    N10[label="expr 1"];
-    N11[label="expr x"];
-    N12[label="expr x -= 1"];
-    N13[label="stmt x -= 1;"];
-    N14[label="block { x -= 1; }"];
-    N15[label="block { let mut x = 10; while x > 0 { x -= 1; } }"];
-    N16[label="expr { let mut x = 10; while x > 0 { x -= 1; } }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N6;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N12;
-    N12 -> N13;
-    N13 -> N14;
-    N14 -> N5;
-    N6 -> N15;
-    N15 -> N16;
-    N16 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f11.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f11.dot-expected.dot
deleted file mode 100644
index 70034d299ba..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f11.dot-expected.dot
+++ /dev/null
@@ -1,35 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 11"];
-    N3[label="local mut _x"];
-    N4[label="stmt let mut _x = 11;"];
-    N5[label="(dummy_node)"];
-    N6[label="expr loop  { _x -= 1; }"];
-    N7[label="expr 1"];
-    N8[label="expr _x"];
-    N9[label="expr _x -= 1"];
-    N10[label="stmt _x -= 1;"];
-    N11[label="block { _x -= 1; }"];
-    N12[label="stmt loop  { _x -= 1; }"];
-    N13[label="expr \"unreachable\""];
-    N14[label="stmt \"unreachable\";"];
-    N15[label="block { let mut _x = 11; loop  { _x -= 1; } \"unreachable\"; }"];
-    N16[label="expr { let mut _x = 11; loop  { _x -= 1; } \"unreachable\"; }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N5;
-    N6 -> N12;
-    N12 -> N13;
-    N13 -> N14;
-    N14 -> N15;
-    N15 -> N16;
-    N16 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f11.rs b/src/test/run-make/graphviz-flowgraph/f11.rs
deleted file mode 100644
index d0f3452119e..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f11.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[allow(unreachable_code)]
-pub fn expr_loop_11() {
-    let mut _x = 11;
-    loop {
-        _x -= 1;
-    }
-    "unreachable";
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f12.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f12.dot-expected.dot
deleted file mode 100644
index 245afc43504..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f12.dot-expected.dot
+++ /dev/null
@@ -1,50 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 12"];
-    N3[label="local mut x"];
-    N4[label="stmt let mut x = 12;"];
-    N5[label="(dummy_node)"];
-    N6[label="expr loop  { x -= 1; if x == 2 { break ; \"unreachable\"; } }"];
-    N7[label="expr 1"];
-    N8[label="expr x"];
-    N9[label="expr x -= 1"];
-    N10[label="stmt x -= 1;"];
-    N11[label="expr x"];
-    N12[label="expr 2"];
-    N13[label="expr x == 2"];
-    N14[label="expr break"];
-    N15[label="(dummy_node)"];
-    N16[label="stmt break ;"];
-    N17[label="expr \"unreachable\""];
-    N18[label="stmt \"unreachable\";"];
-    N19[label="block { break ; \"unreachable\"; }"];
-    N20[label="expr if x == 2 { break ; \"unreachable\"; }"];
-    N21[label="block { x -= 1; if x == 2 { break ; \"unreachable\"; } }"];
-    N22[label="block { let mut x = 12; loop  { x -= 1; if x == 2 { break ; \"unreachable\"; } } }"];
-    N23[label="expr { let mut x = 12; loop  { x -= 1; if x == 2 { break ; \"unreachable\"; } } }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N12;
-    N12 -> N13;
-    N13 -> N14;
-    N14 -> N6;
-    N15 -> N16;
-    N16 -> N17;
-    N17 -> N18;
-    N18 -> N19;
-    N13 -> N20;
-    N19 -> N20;
-    N20 -> N21;
-    N21 -> N5;
-    N6 -> N22;
-    N22 -> N23;
-    N23 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f12.rs b/src/test/run-make/graphviz-flowgraph/f12.rs
deleted file mode 100644
index 90b146340b6..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f12.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[allow(unreachable_code)]
-pub fn expr_loop_12() {
-    let mut x = 12;
-    loop {
-        x -= 1;
-        if x == 2 { break; "unreachable"; }
-    }
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f13.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f13.dot-expected.dot
deleted file mode 100644
index 0f268bd0f2a..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f13.dot-expected.dot
+++ /dev/null
@@ -1,54 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr E13::E13b"];
-    N3[label="expr 13"];
-    N4[label="expr E13::E13b(13)"];
-    N5[label="local x"];
-    N6[label="stmt let x = E13::E13b(13);"];
-    N7[label="local _y"];
-    N8[label="stmt let _y;"];
-    N9[label="expr x"];
-    N10[label="expr match x { E13::E13a => _y = 1, E13::E13b(v) => _y = v + 1, }"];
-    N11[label="(dummy_node)"];
-    N12[label="pat E13::E13a"];
-    N13[label="expr 1"];
-    N14[label="expr _y"];
-    N15[label="expr _y = 1"];
-    N16[label="(dummy_node)"];
-    N17[label="local v"];
-    N18[label="pat E13::E13b(v)"];
-    N19[label="expr v"];
-    N20[label="expr 1"];
-    N21[label="expr v + 1"];
-    N22[label="expr _y"];
-    N23[label="expr _y = v + 1"];
-    N24[label="block {\l    let x = E13::E13b(13);\l    let _y;\l    match x { E13::E13a => _y = 1, E13::E13b(v) => _y = v + 1, }\l}\l"];
-    N25[label="expr {\l    let x = E13::E13b(13);\l    let _y;\l    match x { E13::E13a => _y = 1, E13::E13b(v) => _y = v + 1, }\l}\l"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N12;
-    N12 -> N11;
-    N11 -> N13;
-    N13 -> N14;
-    N14 -> N15;
-    N15 -> N10;
-    N9 -> N17;
-    N17 -> N18;
-    N18 -> N16;
-    N16 -> N19;
-    N19 -> N20;
-    N20 -> N21;
-    N21 -> N22;
-    N22 -> N23;
-    N23 -> N10;
-    N10 -> N24;
-    N24 -> N25;
-    N25 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f13.rs b/src/test/run-make/graphviz-flowgraph/f13.rs
deleted file mode 100644
index babb283c734..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f13.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-enum E13 { E13a, E13b(isize) }
-pub fn expr_match_13() {
-    let x = E13::E13b(13); let _y;
-    match x {
-        E13::E13a => _y = 1,
-        E13::E13b(v) => _y = v + 1,
-    }
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f14.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f14.dot-expected.dot
deleted file mode 100644
index 719a6cf2619..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f14.dot-expected.dot
+++ /dev/null
@@ -1,36 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 14"];
-    N3[label="local x"];
-    N4[label="stmt let x = 14;"];
-    N5[label="expr x"];
-    N6[label="expr 1"];
-    N7[label="expr x > 1"];
-    N8[label="expr return"];
-    N9[label="(dummy_node)"];
-    N10[label="stmt return;"];
-    N11[label="expr \"unreachable\""];
-    N12[label="stmt \"unreachable\";"];
-    N13[label="block { return; \"unreachable\"; }"];
-    N14[label="expr if x > 1 { return; \"unreachable\"; }"];
-    N15[label="block { let x = 14; if x > 1 { return; \"unreachable\"; } }"];
-    N16[label="expr { let x = 14; if x > 1 { return; \"unreachable\"; } }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N1;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N12;
-    N12 -> N13;
-    N7 -> N14;
-    N13 -> N14;
-    N14 -> N15;
-    N15 -> N16;
-    N16 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f14.rs b/src/test/run-make/graphviz-flowgraph/f14.rs
deleted file mode 100644
index 98ff095c831..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f14.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[allow(unreachable_code)]
-pub fn expr_ret_14() {
-    let x = 14;
-    if x > 1 {
-        return;
-        "unreachable";
-    }
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f15.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f15.dot-expected.dot
deleted file mode 100644
index d8cbd8411e2..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f15.dot-expected.dot
+++ /dev/null
@@ -1,105 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 15"];
-    N3[label="local mut x"];
-    N4[label="stmt let mut x = 15;"];
-    N5[label="expr 151"];
-    N6[label="local mut y"];
-    N7[label="stmt let mut y = 151;"];
-    N8[label="(dummy_node)"];
-    N9[label="expr \'outer:\l    loop  {\l        \'inner:\l            loop  {\l                if x == 1 { break \'outer ; \"unreachable\"; }\l                if y >= 2 { break ; \"unreachable\"; }\l                y -= 3;\l            }\l        y -= 4;\l        x -= 5;\l    }\l"];
-    N10[label="(dummy_node)"];
-    N11[label="expr \'inner:\l    loop  {\l        if x == 1 { break \'outer ; \"unreachable\"; }\l        if y >= 2 { break ; \"unreachable\"; }\l        y -= 3;\l    }\l"];
-    N12[label="expr x"];
-    N13[label="expr 1"];
-    N14[label="expr x == 1"];
-    N15[label="expr break \'outer"];
-    N16[label="(dummy_node)"];
-    N17[label="stmt break \'outer ;"];
-    N18[label="expr \"unreachable\""];
-    N19[label="stmt \"unreachable\";"];
-    N20[label="block { break \'outer ; \"unreachable\"; }"];
-    N21[label="expr if x == 1 { break \'outer ; \"unreachable\"; }"];
-    N22[label="stmt if x == 1 { break \'outer ; \"unreachable\"; }"];
-    N23[label="expr y"];
-    N24[label="expr 2"];
-    N25[label="expr y >= 2"];
-    N26[label="expr break"];
-    N27[label="(dummy_node)"];
-    N28[label="stmt break ;"];
-    N29[label="expr \"unreachable\""];
-    N30[label="stmt \"unreachable\";"];
-    N31[label="block { break ; \"unreachable\"; }"];
-    N32[label="expr if y >= 2 { break ; \"unreachable\"; }"];
-    N33[label="stmt if y >= 2 { break ; \"unreachable\"; }"];
-    N34[label="expr 3"];
-    N35[label="expr y"];
-    N36[label="expr y -= 3"];
-    N37[label="stmt y -= 3;"];
-    N38[label="block {\l    if x == 1 { break \'outer ; \"unreachable\"; }\l    if y >= 2 { break ; \"unreachable\"; }\l    y -= 3;\l}\l"];
-    N39[label="stmt \'inner:\l    loop  {\l        if x == 1 { break \'outer ; \"unreachable\"; }\l        if y >= 2 { break ; \"unreachable\"; }\l        y -= 3;\l    }\l"];
-    N40[label="expr 4"];
-    N41[label="expr y"];
-    N42[label="expr y -= 4"];
-    N43[label="stmt y -= 4;"];
-    N44[label="expr 5"];
-    N45[label="expr x"];
-    N46[label="expr x -= 5"];
-    N47[label="stmt x -= 5;"];
-    N48[label="block {\l    \'inner:\l        loop  {\l            if x == 1 { break \'outer ; \"unreachable\"; }\l            if y >= 2 { break ; \"unreachable\"; }\l            y -= 3;\l        }\l    y -= 4;\l    x -= 5;\l}\l"];
-    N49[label="block {\l    let mut x = 15;\l    let mut y = 151;\l    \'outer:\l        loop  {\l            \'inner:\l                loop  {\l                    if x == 1 { break \'outer ; \"unreachable\"; }\l                    if y >= 2 { break ; \"unreachable\"; }\l                    y -= 3;\l                }\l            y -= 4;\l            x -= 5;\l        }\l}\l"];
-    N50[label="expr {\l    let mut x = 15;\l    let mut y = 151;\l    \'outer:\l        loop  {\l            \'inner:\l                loop  {\l                    if x == 1 { break \'outer ; \"unreachable\"; }\l                    if y >= 2 { break ; \"unreachable\"; }\l                    y -= 3;\l                }\l            y -= 4;\l            x -= 5;\l        }\l}\l"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N10;
-    N10 -> N12;
-    N12 -> N13;
-    N13 -> N14;
-    N14 -> N15;
-    N15 -> N9;
-    N16 -> N17;
-    N17 -> N18;
-    N18 -> N19;
-    N19 -> N20;
-    N14 -> N21;
-    N20 -> N21;
-    N21 -> N22;
-    N22 -> N23;
-    N23 -> N24;
-    N24 -> N25;
-    N25 -> N26;
-    N26 -> N11;
-    N27 -> N28;
-    N28 -> N29;
-    N29 -> N30;
-    N30 -> N31;
-    N25 -> N32;
-    N31 -> N32;
-    N32 -> N33;
-    N33 -> N34;
-    N34 -> N35;
-    N35 -> N36;
-    N36 -> N37;
-    N37 -> N38;
-    N38 -> N10;
-    N11 -> N39;
-    N39 -> N40;
-    N40 -> N41;
-    N41 -> N42;
-    N42 -> N43;
-    N43 -> N44;
-    N44 -> N45;
-    N45 -> N46;
-    N46 -> N47;
-    N47 -> N48;
-    N48 -> N8;
-    N9 -> N49;
-    N49 -> N50;
-    N50 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f15.rs b/src/test/run-make/graphviz-flowgraph/f15.rs
deleted file mode 100644
index 056458e5558..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f15.rs
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[allow(unreachable_code)]
-pub fn expr_break_label_15() {
-    let mut x = 15;
-    let mut y = 151;
-    'outer: loop {
-        'inner: loop {
-            if x == 1 {
-                break 'outer;
-                "unreachable";
-            }
-            if y >= 2 {
-                break;
-                "unreachable";
-            }
-            y -= 3;
-        }
-        y -= 4;
-        x -= 5;
-    }
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f16.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f16.dot-expected.dot
deleted file mode 100644
index b11881247fb..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f16.dot-expected.dot
+++ /dev/null
@@ -1,111 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 16"];
-    N3[label="local mut x"];
-    N4[label="stmt let mut x = 16;"];
-    N5[label="expr 16"];
-    N6[label="local mut y"];
-    N7[label="stmt let mut y = 16;"];
-    N8[label="(dummy_node)"];
-    N9[label="expr \'outer:\l    loop  {\l        \'inner:\l            loop  {\l                if x == 1 { continue \'outer ; \"unreachable\"; }\l                if y >= 1 { break ; \"unreachable\"; }\l                y -= 1;\l            }\l        y -= 1;\l        x -= 1;\l    }\l"];
-    N10[label="(dummy_node)"];
-    N11[label="expr \'inner:\l    loop  {\l        if x == 1 { continue \'outer ; \"unreachable\"; }\l        if y >= 1 { break ; \"unreachable\"; }\l        y -= 1;\l    }\l"];
-    N12[label="expr x"];
-    N13[label="expr 1"];
-    N14[label="expr x == 1"];
-    N15[label="expr continue \'outer"];
-    N16[label="(dummy_node)"];
-    N17[label="stmt continue \'outer ;"];
-    N18[label="expr \"unreachable\""];
-    N19[label="stmt \"unreachable\";"];
-    N20[label="block { continue \'outer ; \"unreachable\"; }"];
-    N21[label="expr if x == 1 { continue \'outer ; \"unreachable\"; }"];
-    N22[label="stmt if x == 1 { continue \'outer ; \"unreachable\"; }"];
-    N23[label="expr y"];
-    N24[label="expr 1"];
-    N25[label="expr y >= 1"];
-    N26[label="expr break"];
-    N27[label="(dummy_node)"];
-    N28[label="stmt break ;"];
-    N29[label="expr \"unreachable\""];
-    N30[label="stmt \"unreachable\";"];
-    N31[label="block { break ; \"unreachable\"; }"];
-    N32[label="expr if y >= 1 { break ; \"unreachable\"; }"];
-    N33[label="stmt if y >= 1 { break ; \"unreachable\"; }"];
-    N34[label="expr 1"];
-    N35[label="expr y"];
-    N36[label="expr y -= 1"];
-    N37[label="stmt y -= 1;"];
-    N38[label="block {\l    if x == 1 { continue \'outer ; \"unreachable\"; }\l    if y >= 1 { break ; \"unreachable\"; }\l    y -= 1;\l}\l"];
-    N39[label="stmt \'inner:\l    loop  {\l        if x == 1 { continue \'outer ; \"unreachable\"; }\l        if y >= 1 { break ; \"unreachable\"; }\l        y -= 1;\l    }\l"];
-    N40[label="expr 1"];
-    N41[label="expr y"];
-    N42[label="expr y -= 1"];
-    N43[label="stmt y -= 1;"];
-    N44[label="expr 1"];
-    N45[label="expr x"];
-    N46[label="expr x -= 1"];
-    N47[label="stmt x -= 1;"];
-    N48[label="block {\l    \'inner:\l        loop  {\l            if x == 1 { continue \'outer ; \"unreachable\"; }\l            if y >= 1 { break ; \"unreachable\"; }\l            y -= 1;\l        }\l    y -= 1;\l    x -= 1;\l}\l"];
-    N49[label="stmt \'outer:\l    loop  {\l        \'inner:\l            loop  {\l                if x == 1 { continue \'outer ; \"unreachable\"; }\l                if y >= 1 { break ; \"unreachable\"; }\l                y -= 1;\l            }\l        y -= 1;\l        x -= 1;\l    }\l"];
-    N50[label="expr \"unreachable\""];
-    N51[label="stmt \"unreachable\";"];
-    N52[label="block {\l    let mut x = 16;\l    let mut y = 16;\l    \'outer:\l        loop  {\l            \'inner:\l                loop  {\l                    if x == 1 { continue \'outer ; \"unreachable\"; }\l                    if y >= 1 { break ; \"unreachable\"; }\l                    y -= 1;\l                }\l            y -= 1;\l            x -= 1;\l        }\l    \"unreachable\";\l}\l"];
-    N53[label="expr {\l    let mut x = 16;\l    let mut y = 16;\l    \'outer:\l        loop  {\l            \'inner:\l                loop  {\l                    if x == 1 { continue \'outer ; \"unreachable\"; }\l                    if y >= 1 { break ; \"unreachable\"; }\l                    y -= 1;\l                }\l            y -= 1;\l            x -= 1;\l        }\l    \"unreachable\";\l}\l"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N10;
-    N10 -> N12;
-    N12 -> N13;
-    N13 -> N14;
-    N14 -> N15;
-    N15 -> N8;
-    N16 -> N17;
-    N17 -> N18;
-    N18 -> N19;
-    N19 -> N20;
-    N14 -> N21;
-    N20 -> N21;
-    N21 -> N22;
-    N22 -> N23;
-    N23 -> N24;
-    N24 -> N25;
-    N25 -> N26;
-    N26 -> N11;
-    N27 -> N28;
-    N28 -> N29;
-    N29 -> N30;
-    N30 -> N31;
-    N25 -> N32;
-    N31 -> N32;
-    N32 -> N33;
-    N33 -> N34;
-    N34 -> N35;
-    N35 -> N36;
-    N36 -> N37;
-    N37 -> N38;
-    N38 -> N10;
-    N11 -> N39;
-    N39 -> N40;
-    N40 -> N41;
-    N41 -> N42;
-    N42 -> N43;
-    N43 -> N44;
-    N44 -> N45;
-    N45 -> N46;
-    N46 -> N47;
-    N47 -> N48;
-    N48 -> N8;
-    N9 -> N49;
-    N49 -> N50;
-    N50 -> N51;
-    N51 -> N52;
-    N52 -> N53;
-    N53 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f16.rs b/src/test/run-make/graphviz-flowgraph/f16.rs
deleted file mode 100644
index e225b0080e5..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f16.rs
+++ /dev/null
@@ -1,31 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[allow(unreachable_code)]
-pub fn expr_continue_label_16() {
-    let mut x = 16;
-    let mut y = 16;
-    'outer: loop {
-        'inner: loop {
-            if x == 1 {
-                continue 'outer;
-                "unreachable";
-            }
-            if y >= 1 {
-                break;
-                "unreachable";
-            }
-            y -= 1;
-        }
-        y -= 1;
-        x -= 1;
-    }
-    "unreachable";
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f17.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f17.dot-expected.dot
deleted file mode 100644
index 705eece7755..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f17.dot-expected.dot
+++ /dev/null
@@ -1,21 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 1"];
-    N3[label="expr 7"];
-    N4[label="expr 17"];
-    N5[label="expr [1, 7, 17]"];
-    N6[label="local _v"];
-    N7[label="stmt let _v = [1, 7, 17];"];
-    N8[label="block { let _v = [1, 7, 17]; }"];
-    N9[label="expr { let _v = [1, 7, 17]; }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f17.rs b/src/test/run-make/graphviz-flowgraph/f17.rs
deleted file mode 100644
index 23f5bb8a1eb..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f17.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-pub fn expr_vec_17() {
-    let _v = [1, 7, 17];
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f18.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f18.dot-expected.dot
deleted file mode 100644
index b0491fe6e27..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f18.dot-expected.dot
+++ /dev/null
@@ -1,23 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="stmt fn inner(x: isize) -> isize { x + x }"];
-    N3[label="expr inner"];
-    N4[label="expr inner"];
-    N5[label="expr 18"];
-    N6[label="expr inner(18)"];
-    N7[label="expr inner(inner(18))"];
-    N8[label="stmt inner(inner(18));"];
-    N9[label="block {\l    fn inner(x: isize) -> isize { x + x }\l    inner(inner(18));\l}\l"];
-    N10[label="expr {\l    fn inner(x: isize) -> isize { x + x }\l    inner(inner(18));\l}\l"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N10;
-    N10 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f18.rs b/src/test/run-make/graphviz-flowgraph/f18.rs
deleted file mode 100644
index cbf8aa5db43..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f18.rs
+++ /dev/null
@@ -1,14 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-pub fn expr_call_18() {
-    fn inner(x:isize) -> isize { x + x }
-    inner(inner(18));
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f19.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f19.dot-expected.dot
deleted file mode 100644
index 223978c3d76..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f19.dot-expected.dot
+++ /dev/null
@@ -1,29 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="stmt struct S19 {\l    x: isize,\l}\l"];
-    N3[label="stmt impl S19 {\l    fn inner(self: Self) -> S19 { S19{x: self.x + self.x,} }\l}\l"];
-    N4[label="expr 19"];
-    N5[label="expr S19{x: 19,}"];
-    N6[label="local s"];
-    N7[label="stmt let s = S19{x: 19,};"];
-    N8[label="expr s"];
-    N9[label="expr s.inner()"];
-    N10[label="expr s.inner().inner()"];
-    N11[label="stmt s.inner().inner();"];
-    N12[label="block {\l    struct S19 {\l        x: isize,\l    }\l    impl S19 {\l        fn inner(self: Self) -> S19 { S19{x: self.x + self.x,} }\l    }\l    let s = S19{x: 19,};\l    s.inner().inner();\l}\l"];
-    N13[label="expr {\l    struct S19 {\l        x: isize,\l    }\l    impl S19 {\l        fn inner(self: Self) -> S19 { S19{x: self.x + self.x,} }\l    }\l    let s = S19{x: 19,};\l    s.inner().inner();\l}\l"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N12;
-    N12 -> N13;
-    N13 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f19.rs b/src/test/run-make/graphviz-flowgraph/f19.rs
deleted file mode 100644
index 78c15dd64ad..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f19.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-pub fn expr_method_call_19() {
-    struct S19 { x: isize }
-    impl S19 { fn inner(self) -> S19 { S19 { x: self.x + self.x } } }
-    let s = S19 { x: 19 };
-    s.inner().inner();
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f20.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f20.dot-expected.dot
deleted file mode 100644
index 120eab4dac9..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f20.dot-expected.dot
+++ /dev/null
@@ -1,29 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 2"];
-    N3[label="expr 0"];
-    N4[label="expr 20"];
-    N5[label="expr [2, 0, 20]"];
-    N6[label="local v"];
-    N7[label="stmt let v = [2, 0, 20];"];
-    N8[label="expr v"];
-    N9[label="expr 20"];
-    N10[label="expr v[20]"];
-    N11[label="stmt v[20];"];
-    N12[label="block { let v = [2, 0, 20]; v[20]; }"];
-    N13[label="expr { let v = [2, 0, 20]; v[20]; }"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N12;
-    N12 -> N13;
-    N13 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f20.rs b/src/test/run-make/graphviz-flowgraph/f20.rs
deleted file mode 100644
index d7349932355..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f20.rs
+++ /dev/null
@@ -1,14 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-pub fn expr_index_20() {
-    let v = [2, 0, 20];
-    v[20];
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f21.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f21.dot-expected.dot
deleted file mode 100644
index 370dcdd8554..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f21.dot-expected.dot
+++ /dev/null
@@ -1,101 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 15"];
-    N3[label="local mut x"];
-    N4[label="stmt let mut x = 15;"];
-    N5[label="expr 151"];
-    N6[label="local mut y"];
-    N7[label="stmt let mut y = 151;"];
-    N8[label="(dummy_node)"];
-    N9[label="expr \'outer:\l    loop  {\l        \'inner:\l            loop  {\l                if x == 1 { break \'outer ; \"unreachable\"; }\l                if y >= 2 { return; \"unreachable\"; }\l                y -= 3;\l                x -= 5;\l            }\l        \"unreachable\";\l    }\l"];
-    N10[label="(dummy_node)"];
-    N11[label="expr \'inner:\l    loop  {\l        if x == 1 { break \'outer ; \"unreachable\"; }\l        if y >= 2 { return; \"unreachable\"; }\l        y -= 3;\l        x -= 5;\l    }\l"];
-    N12[label="expr x"];
-    N13[label="expr 1"];
-    N14[label="expr x == 1"];
-    N15[label="expr break \'outer"];
-    N16[label="(dummy_node)"];
-    N17[label="stmt break \'outer ;"];
-    N18[label="expr \"unreachable\""];
-    N19[label="stmt \"unreachable\";"];
-    N20[label="block { break \'outer ; \"unreachable\"; }"];
-    N21[label="expr if x == 1 { break \'outer ; \"unreachable\"; }"];
-    N22[label="stmt if x == 1 { break \'outer ; \"unreachable\"; }"];
-    N23[label="expr y"];
-    N24[label="expr 2"];
-    N25[label="expr y >= 2"];
-    N26[label="expr return"];
-    N27[label="(dummy_node)"];
-    N28[label="stmt return;"];
-    N29[label="expr \"unreachable\""];
-    N30[label="stmt \"unreachable\";"];
-    N31[label="block { return; \"unreachable\"; }"];
-    N32[label="expr if y >= 2 { return; \"unreachable\"; }"];
-    N33[label="stmt if y >= 2 { return; \"unreachable\"; }"];
-    N34[label="expr 3"];
-    N35[label="expr y"];
-    N36[label="expr y -= 3"];
-    N37[label="stmt y -= 3;"];
-    N38[label="expr 5"];
-    N39[label="expr x"];
-    N40[label="expr x -= 5"];
-    N41[label="stmt x -= 5;"];
-    N42[label="block {\l    if x == 1 { break \'outer ; \"unreachable\"; }\l    if y >= 2 { return; \"unreachable\"; }\l    y -= 3;\l    x -= 5;\l}\l"];
-    N43[label="stmt \'inner:\l    loop  {\l        if x == 1 { break \'outer ; \"unreachable\"; }\l        if y >= 2 { return; \"unreachable\"; }\l        y -= 3;\l        x -= 5;\l    }\l"];
-    N44[label="expr \"unreachable\""];
-    N45[label="stmt \"unreachable\";"];
-    N46[label="block {\l    \'inner:\l        loop  {\l            if x == 1 { break \'outer ; \"unreachable\"; }\l            if y >= 2 { return; \"unreachable\"; }\l            y -= 3;\l            x -= 5;\l        }\l    \"unreachable\";\l}\l"];
-    N47[label="block {\l    let mut x = 15;\l    let mut y = 151;\l    \'outer:\l        loop  {\l            \'inner:\l                loop  {\l                    if x == 1 { break \'outer ; \"unreachable\"; }\l                    if y >= 2 { return; \"unreachable\"; }\l                    y -= 3;\l                    x -= 5;\l                }\l            \"unreachable\";\l        }\l}\l"];
-    N48[label="expr {\l    let mut x = 15;\l    let mut y = 151;\l    \'outer:\l        loop  {\l            \'inner:\l                loop  {\l                    if x == 1 { break \'outer ; \"unreachable\"; }\l                    if y >= 2 { return; \"unreachable\"; }\l                    y -= 3;\l                    x -= 5;\l                }\l            \"unreachable\";\l        }\l}\l"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N10;
-    N10 -> N12;
-    N12 -> N13;
-    N13 -> N14;
-    N14 -> N15;
-    N15 -> N9;
-    N16 -> N17;
-    N17 -> N18;
-    N18 -> N19;
-    N19 -> N20;
-    N14 -> N21;
-    N20 -> N21;
-    N21 -> N22;
-    N22 -> N23;
-    N23 -> N24;
-    N24 -> N25;
-    N25 -> N26;
-    N26 -> N1;
-    N27 -> N28;
-    N28 -> N29;
-    N29 -> N30;
-    N30 -> N31;
-    N25 -> N32;
-    N31 -> N32;
-    N32 -> N33;
-    N33 -> N34;
-    N34 -> N35;
-    N35 -> N36;
-    N36 -> N37;
-    N37 -> N38;
-    N38 -> N39;
-    N39 -> N40;
-    N40 -> N41;
-    N41 -> N42;
-    N42 -> N10;
-    N11 -> N43;
-    N43 -> N44;
-    N44 -> N45;
-    N45 -> N46;
-    N46 -> N8;
-    N9 -> N47;
-    N47 -> N48;
-    N48 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f21.rs b/src/test/run-make/graphviz-flowgraph/f21.rs
deleted file mode 100644
index 70083ed8312..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f21.rs
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[allow(unreachable_code)]
-pub fn expr_break_label_21() {
-    let mut x = 15;
-    let mut y = 151;
-    'outer: loop {
-        'inner: loop {
-            if x == 1 {
-                break 'outer;
-                "unreachable";
-            }
-            if y >= 2 {
-                return;
-                "unreachable";
-            }
-            y -= 3;
-            x -= 5;
-        }
-        "unreachable";
-    }
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f22.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f22.dot-expected.dot
deleted file mode 100644
index 9d3bc22831a..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f22.dot-expected.dot
+++ /dev/null
@@ -1,107 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 15"];
-    N3[label="local mut x"];
-    N4[label="stmt let mut x = 15;"];
-    N5[label="expr 151"];
-    N6[label="local mut y"];
-    N7[label="stmt let mut y = 151;"];
-    N8[label="(dummy_node)"];
-    N9[label="expr \'outer:\l    loop  {\l        \'inner:\l            loop  {\l                if x == 1 { continue \'outer ; \"unreachable\"; }\l                if y >= 2 { return; \"unreachable\"; }\l                x -= 1;\l                y -= 3;\l            }\l        \"unreachable\";\l    }\l"];
-    N10[label="(dummy_node)"];
-    N11[label="expr \'inner:\l    loop  {\l        if x == 1 { continue \'outer ; \"unreachable\"; }\l        if y >= 2 { return; \"unreachable\"; }\l        x -= 1;\l        y -= 3;\l    }\l"];
-    N12[label="expr x"];
-    N13[label="expr 1"];
-    N14[label="expr x == 1"];
-    N15[label="expr continue \'outer"];
-    N16[label="(dummy_node)"];
-    N17[label="stmt continue \'outer ;"];
-    N18[label="expr \"unreachable\""];
-    N19[label="stmt \"unreachable\";"];
-    N20[label="block { continue \'outer ; \"unreachable\"; }"];
-    N21[label="expr if x == 1 { continue \'outer ; \"unreachable\"; }"];
-    N22[label="stmt if x == 1 { continue \'outer ; \"unreachable\"; }"];
-    N23[label="expr y"];
-    N24[label="expr 2"];
-    N25[label="expr y >= 2"];
-    N26[label="expr return"];
-    N27[label="(dummy_node)"];
-    N28[label="stmt return;"];
-    N29[label="expr \"unreachable\""];
-    N30[label="stmt \"unreachable\";"];
-    N31[label="block { return; \"unreachable\"; }"];
-    N32[label="expr if y >= 2 { return; \"unreachable\"; }"];
-    N33[label="stmt if y >= 2 { return; \"unreachable\"; }"];
-    N34[label="expr 1"];
-    N35[label="expr x"];
-    N36[label="expr x -= 1"];
-    N37[label="stmt x -= 1;"];
-    N38[label="expr 3"];
-    N39[label="expr y"];
-    N40[label="expr y -= 3"];
-    N41[label="stmt y -= 3;"];
-    N42[label="block {\l    if x == 1 { continue \'outer ; \"unreachable\"; }\l    if y >= 2 { return; \"unreachable\"; }\l    x -= 1;\l    y -= 3;\l}\l"];
-    N43[label="stmt \'inner:\l    loop  {\l        if x == 1 { continue \'outer ; \"unreachable\"; }\l        if y >= 2 { return; \"unreachable\"; }\l        x -= 1;\l        y -= 3;\l    }\l"];
-    N44[label="expr \"unreachable\""];
-    N45[label="stmt \"unreachable\";"];
-    N46[label="block {\l    \'inner:\l        loop  {\l            if x == 1 { continue \'outer ; \"unreachable\"; }\l            if y >= 2 { return; \"unreachable\"; }\l            x -= 1;\l            y -= 3;\l        }\l    \"unreachable\";\l}\l"];
-    N47[label="stmt \'outer:\l    loop  {\l        \'inner:\l            loop  {\l                if x == 1 { continue \'outer ; \"unreachable\"; }\l                if y >= 2 { return; \"unreachable\"; }\l                x -= 1;\l                y -= 3;\l            }\l        \"unreachable\";\l    }\l"];
-    N48[label="expr \"unreachable\""];
-    N49[label="stmt \"unreachable\";"];
-    N50[label="block {\l    let mut x = 15;\l    let mut y = 151;\l    \'outer:\l        loop  {\l            \'inner:\l                loop  {\l                    if x == 1 { continue \'outer ; \"unreachable\"; }\l                    if y >= 2 { return; \"unreachable\"; }\l                    x -= 1;\l                    y -= 3;\l                }\l            \"unreachable\";\l        }\l    \"unreachable\";\l}\l"];
-    N51[label="expr {\l    let mut x = 15;\l    let mut y = 151;\l    \'outer:\l        loop  {\l            \'inner:\l                loop  {\l                    if x == 1 { continue \'outer ; \"unreachable\"; }\l                    if y >= 2 { return; \"unreachable\"; }\l                    x -= 1;\l                    y -= 3;\l                }\l            \"unreachable\";\l        }\l    \"unreachable\";\l}\l"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N10;
-    N10 -> N12;
-    N12 -> N13;
-    N13 -> N14;
-    N14 -> N15;
-    N15 -> N8;
-    N16 -> N17;
-    N17 -> N18;
-    N18 -> N19;
-    N19 -> N20;
-    N14 -> N21;
-    N20 -> N21;
-    N21 -> N22;
-    N22 -> N23;
-    N23 -> N24;
-    N24 -> N25;
-    N25 -> N26;
-    N26 -> N1;
-    N27 -> N28;
-    N28 -> N29;
-    N29 -> N30;
-    N30 -> N31;
-    N25 -> N32;
-    N31 -> N32;
-    N32 -> N33;
-    N33 -> N34;
-    N34 -> N35;
-    N35 -> N36;
-    N36 -> N37;
-    N37 -> N38;
-    N38 -> N39;
-    N39 -> N40;
-    N40 -> N41;
-    N41 -> N42;
-    N42 -> N10;
-    N11 -> N43;
-    N43 -> N44;
-    N44 -> N45;
-    N45 -> N46;
-    N46 -> N8;
-    N9 -> N47;
-    N47 -> N48;
-    N48 -> N49;
-    N49 -> N50;
-    N50 -> N51;
-    N51 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f22.rs b/src/test/run-make/graphviz-flowgraph/f22.rs
deleted file mode 100644
index b35aac9ec42..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f22.rs
+++ /dev/null
@@ -1,31 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[allow(unreachable_code)]
-pub fn expr_break_label_21() {
-    let mut x = 15;
-    let mut y = 151;
-    'outer: loop {
-        'inner: loop {
-            if x == 1 {
-                continue 'outer;
-                "unreachable";
-            }
-            if y >= 2 {
-                return;
-                "unreachable";
-            }
-            x -= 1;
-            y -= 3;
-        }
-        "unreachable";
-    }
-    "unreachable";
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f23.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f23.dot-expected.dot
deleted file mode 100644
index c8bfcd6510b..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f23.dot-expected.dot
+++ /dev/null
@@ -1,113 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 23"];
-    N3[label="local mut x"];
-    N4[label="stmt let mut x = 23;"];
-    N5[label="expr 23"];
-    N6[label="local mut y"];
-    N7[label="stmt let mut y = 23;"];
-    N8[label="expr 23"];
-    N9[label="local mut z"];
-    N10[label="stmt let mut z = 23;"];
-    N11[label="(dummy_node)"];
-    N12[label="expr while x > 0 {\l    x -= 1;\l    while y > 0 {\l        y -= 1;\l        while z > 0 { z -= 1; }\l        if x > 10 { return; \"unreachable\"; }\l    }\l}\l"];
-    N13[label="expr x"];
-    N14[label="expr 0"];
-    N15[label="expr x > 0"];
-    N16[label="expr 1"];
-    N17[label="expr x"];
-    N18[label="expr x -= 1"];
-    N19[label="stmt x -= 1;"];
-    N20[label="(dummy_node)"];
-    N21[label="expr while y > 0 {\l    y -= 1;\l    while z > 0 { z -= 1; }\l    if x > 10 { return; \"unreachable\"; }\l}\l"];
-    N22[label="expr y"];
-    N23[label="expr 0"];
-    N24[label="expr y > 0"];
-    N25[label="expr 1"];
-    N26[label="expr y"];
-    N27[label="expr y -= 1"];
-    N28[label="stmt y -= 1;"];
-    N29[label="(dummy_node)"];
-    N30[label="expr while z > 0 { z -= 1; }"];
-    N31[label="expr z"];
-    N32[label="expr 0"];
-    N33[label="expr z > 0"];
-    N34[label="expr 1"];
-    N35[label="expr z"];
-    N36[label="expr z -= 1"];
-    N37[label="stmt z -= 1;"];
-    N38[label="block { z -= 1; }"];
-    N39[label="stmt while z > 0 { z -= 1; }"];
-    N40[label="expr x"];
-    N41[label="expr 10"];
-    N42[label="expr x > 10"];
-    N43[label="expr return"];
-    N44[label="(dummy_node)"];
-    N45[label="stmt return;"];
-    N46[label="expr \"unreachable\""];
-    N47[label="stmt \"unreachable\";"];
-    N48[label="block { return; \"unreachable\"; }"];
-    N49[label="expr if x > 10 { return; \"unreachable\"; }"];
-    N50[label="block { y -= 1; while z > 0 { z -= 1; } if x > 10 { return; \"unreachable\"; } }"];
-    N51[label="block {\l    x -= 1;\l    while y > 0 {\l        y -= 1;\l        while z > 0 { z -= 1; }\l        if x > 10 { return; \"unreachable\"; }\l    }\l}\l"];
-    N52[label="block {\l    let mut x = 23;\l    let mut y = 23;\l    let mut z = 23;\l    while x > 0 {\l        x -= 1;\l        while y > 0 {\l            y -= 1;\l            while z > 0 { z -= 1; }\l            if x > 10 { return; \"unreachable\"; }\l        }\l    }\l}\l"];
-    N53[label="expr {\l    let mut x = 23;\l    let mut y = 23;\l    let mut z = 23;\l    while x > 0 {\l        x -= 1;\l        while y > 0 {\l            y -= 1;\l            while z > 0 { z -= 1; }\l            if x > 10 { return; \"unreachable\"; }\l        }\l    }\l}\l"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N13;
-    N13 -> N14;
-    N14 -> N15;
-    N15 -> N12;
-    N15 -> N16;
-    N16 -> N17;
-    N17 -> N18;
-    N18 -> N19;
-    N19 -> N20;
-    N20 -> N22;
-    N22 -> N23;
-    N23 -> N24;
-    N24 -> N21;
-    N24 -> N25;
-    N25 -> N26;
-    N26 -> N27;
-    N27 -> N28;
-    N28 -> N29;
-    N29 -> N31;
-    N31 -> N32;
-    N32 -> N33;
-    N33 -> N30;
-    N33 -> N34;
-    N34 -> N35;
-    N35 -> N36;
-    N36 -> N37;
-    N37 -> N38;
-    N38 -> N29;
-    N30 -> N39;
-    N39 -> N40;
-    N40 -> N41;
-    N41 -> N42;
-    N42 -> N43;
-    N43 -> N1;
-    N44 -> N45;
-    N45 -> N46;
-    N46 -> N47;
-    N47 -> N48;
-    N42 -> N49;
-    N48 -> N49;
-    N49 -> N50;
-    N50 -> N20;
-    N21 -> N51;
-    N51 -> N11;
-    N12 -> N52;
-    N52 -> N53;
-    N53 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f24.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f24.dot-expected.dot
deleted file mode 100644
index e40dd014f0a..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f24.dot-expected.dot
+++ /dev/null
@@ -1,161 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 24"];
-    N3[label="local mut x"];
-    N4[label="stmt let mut x = 24;"];
-    N5[label="expr 24"];
-    N6[label="local mut y"];
-    N7[label="stmt let mut y = 24;"];
-    N8[label="expr 24"];
-    N9[label="local mut z"];
-    N10[label="stmt let mut z = 24;"];
-    N11[label="(dummy_node)"];
-    N12[label="expr loop  {\l    if x == 0 { break ; \"unreachable\"; }\l    x -= 1;\l    loop  {\l        if y == 0 { break ; \"unreachable\"; }\l        y -= 1;\l        loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l        if x > 10 { return; \"unreachable\"; }\l    }\l}\l"];
-    N13[label="expr x"];
-    N14[label="expr 0"];
-    N15[label="expr x == 0"];
-    N16[label="expr break"];
-    N17[label="(dummy_node)"];
-    N18[label="stmt break ;"];
-    N19[label="expr \"unreachable\""];
-    N20[label="stmt \"unreachable\";"];
-    N21[label="block { break ; \"unreachable\"; }"];
-    N22[label="expr if x == 0 { break ; \"unreachable\"; }"];
-    N23[label="stmt if x == 0 { break ; \"unreachable\"; }"];
-    N24[label="expr 1"];
-    N25[label="expr x"];
-    N26[label="expr x -= 1"];
-    N27[label="stmt x -= 1;"];
-    N28[label="(dummy_node)"];
-    N29[label="expr loop  {\l    if y == 0 { break ; \"unreachable\"; }\l    y -= 1;\l    loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l    if x > 10 { return; \"unreachable\"; }\l}\l"];
-    N30[label="expr y"];
-    N31[label="expr 0"];
-    N32[label="expr y == 0"];
-    N33[label="expr break"];
-    N34[label="(dummy_node)"];
-    N35[label="stmt break ;"];
-    N36[label="expr \"unreachable\""];
-    N37[label="stmt \"unreachable\";"];
-    N38[label="block { break ; \"unreachable\"; }"];
-    N39[label="expr if y == 0 { break ; \"unreachable\"; }"];
-    N40[label="stmt if y == 0 { break ; \"unreachable\"; }"];
-    N41[label="expr 1"];
-    N42[label="expr y"];
-    N43[label="expr y -= 1"];
-    N44[label="stmt y -= 1;"];
-    N45[label="(dummy_node)"];
-    N46[label="expr loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }"];
-    N47[label="expr z"];
-    N48[label="expr 0"];
-    N49[label="expr z == 0"];
-    N50[label="expr break"];
-    N51[label="(dummy_node)"];
-    N52[label="stmt break ;"];
-    N53[label="expr \"unreachable\""];
-    N54[label="stmt \"unreachable\";"];
-    N55[label="block { break ; \"unreachable\"; }"];
-    N56[label="expr if z == 0 { break ; \"unreachable\"; }"];
-    N57[label="stmt if z == 0 { break ; \"unreachable\"; }"];
-    N58[label="expr 1"];
-    N59[label="expr z"];
-    N60[label="expr z -= 1"];
-    N61[label="stmt z -= 1;"];
-    N62[label="block { if z == 0 { break ; \"unreachable\"; } z -= 1; }"];
-    N63[label="stmt loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }"];
-    N64[label="expr x"];
-    N65[label="expr 10"];
-    N66[label="expr x > 10"];
-    N67[label="expr return"];
-    N68[label="(dummy_node)"];
-    N69[label="stmt return;"];
-    N70[label="expr \"unreachable\""];
-    N71[label="stmt \"unreachable\";"];
-    N72[label="block { return; \"unreachable\"; }"];
-    N73[label="expr if x > 10 { return; \"unreachable\"; }"];
-    N74[label="block {\l    if y == 0 { break ; \"unreachable\"; }\l    y -= 1;\l    loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l    if x > 10 { return; \"unreachable\"; }\l}\l"];
-    N75[label="block {\l    if x == 0 { break ; \"unreachable\"; }\l    x -= 1;\l    loop  {\l        if y == 0 { break ; \"unreachable\"; }\l        y -= 1;\l        loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l        if x > 10 { return; \"unreachable\"; }\l    }\l}\l"];
-    N76[label="block {\l    let mut x = 24;\l    let mut y = 24;\l    let mut z = 24;\l    loop  {\l        if x == 0 { break ; \"unreachable\"; }\l        x -= 1;\l        loop  {\l            if y == 0 { break ; \"unreachable\"; }\l            y -= 1;\l            loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l            if x > 10 { return; \"unreachable\"; }\l        }\l    }\l}\l"];
-    N77[label="expr {\l    let mut x = 24;\l    let mut y = 24;\l    let mut z = 24;\l    loop  {\l        if x == 0 { break ; \"unreachable\"; }\l        x -= 1;\l        loop  {\l            if y == 0 { break ; \"unreachable\"; }\l            y -= 1;\l            loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l            if x > 10 { return; \"unreachable\"; }\l        }\l    }\l}\l"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N13;
-    N13 -> N14;
-    N14 -> N15;
-    N15 -> N16;
-    N16 -> N12;
-    N17 -> N18;
-    N18 -> N19;
-    N19 -> N20;
-    N20 -> N21;
-    N15 -> N22;
-    N21 -> N22;
-    N22 -> N23;
-    N23 -> N24;
-    N24 -> N25;
-    N25 -> N26;
-    N26 -> N27;
-    N27 -> N28;
-    N28 -> N30;
-    N30 -> N31;
-    N31 -> N32;
-    N32 -> N33;
-    N33 -> N29;
-    N34 -> N35;
-    N35 -> N36;
-    N36 -> N37;
-    N37 -> N38;
-    N32 -> N39;
-    N38 -> N39;
-    N39 -> N40;
-    N40 -> N41;
-    N41 -> N42;
-    N42 -> N43;
-    N43 -> N44;
-    N44 -> N45;
-    N45 -> N47;
-    N47 -> N48;
-    N48 -> N49;
-    N49 -> N50;
-    N50 -> N46;
-    N51 -> N52;
-    N52 -> N53;
-    N53 -> N54;
-    N54 -> N55;
-    N49 -> N56;
-    N55 -> N56;
-    N56 -> N57;
-    N57 -> N58;
-    N58 -> N59;
-    N59 -> N60;
-    N60 -> N61;
-    N61 -> N62;
-    N62 -> N45;
-    N46 -> N63;
-    N63 -> N64;
-    N64 -> N65;
-    N65 -> N66;
-    N66 -> N67;
-    N67 -> N1;
-    N68 -> N69;
-    N69 -> N70;
-    N70 -> N71;
-    N71 -> N72;
-    N66 -> N73;
-    N72 -> N73;
-    N73 -> N74;
-    N74 -> N28;
-    N29 -> N75;
-    N75 -> N11;
-    N12 -> N76;
-    N76 -> N77;
-    N77 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f24.rs b/src/test/run-make/graphviz-flowgraph/f24.rs
deleted file mode 100644
index f796d660a18..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f24.rs
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[allow(unreachable_code)]
-pub fn expr_while_24() {
-    let mut x = 24;
-    let mut y = 24;
-    let mut z = 24;
-
-    loop {
-        if x == 0 { break; "unreachable"; }
-        x -= 1;
-
-        loop {
-            if y == 0 { break; "unreachable"; }
-            y -= 1;
-
-            loop {
-                if z == 0 { break; "unreachable"; }
-                z -= 1;
-            }
-
-            if x > 10 {
-                return;
-                "unreachable";
-            }
-        }
-    }
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f25.dot-expected.dot b/src/test/run-make/graphviz-flowgraph/f25.dot-expected.dot
deleted file mode 100644
index 1e2df1ab5e7..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f25.dot-expected.dot
+++ /dev/null
@@ -1,161 +0,0 @@
-digraph block {
-    N0[label="entry"];
-    N1[label="exit"];
-    N2[label="expr 25"];
-    N3[label="local mut x"];
-    N4[label="stmt let mut x = 25;"];
-    N5[label="expr 25"];
-    N6[label="local mut y"];
-    N7[label="stmt let mut y = 25;"];
-    N8[label="expr 25"];
-    N9[label="local mut z"];
-    N10[label="stmt let mut z = 25;"];
-    N11[label="(dummy_node)"];
-    N12[label="expr \'a:\l    loop  {\l        if x == 0 { break ; \"unreachable\"; }\l        x -= 1;\l        \'a:\l            loop  {\l                if y == 0 { break ; \"unreachable\"; }\l                y -= 1;\l                \'a: loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l                if x > 10 { continue \'a ; \"unreachable\"; }\l            }\l    }\l"];
-    N13[label="expr x"];
-    N14[label="expr 0"];
-    N15[label="expr x == 0"];
-    N16[label="expr break"];
-    N17[label="(dummy_node)"];
-    N18[label="stmt break ;"];
-    N19[label="expr \"unreachable\""];
-    N20[label="stmt \"unreachable\";"];
-    N21[label="block { break ; \"unreachable\"; }"];
-    N22[label="expr if x == 0 { break ; \"unreachable\"; }"];
-    N23[label="stmt if x == 0 { break ; \"unreachable\"; }"];
-    N24[label="expr 1"];
-    N25[label="expr x"];
-    N26[label="expr x -= 1"];
-    N27[label="stmt x -= 1;"];
-    N28[label="(dummy_node)"];
-    N29[label="expr \'a:\l    loop  {\l        if y == 0 { break ; \"unreachable\"; }\l        y -= 1;\l        \'a: loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l        if x > 10 { continue \'a ; \"unreachable\"; }\l    }\l"];
-    N30[label="expr y"];
-    N31[label="expr 0"];
-    N32[label="expr y == 0"];
-    N33[label="expr break"];
-    N34[label="(dummy_node)"];
-    N35[label="stmt break ;"];
-    N36[label="expr \"unreachable\""];
-    N37[label="stmt \"unreachable\";"];
-    N38[label="block { break ; \"unreachable\"; }"];
-    N39[label="expr if y == 0 { break ; \"unreachable\"; }"];
-    N40[label="stmt if y == 0 { break ; \"unreachable\"; }"];
-    N41[label="expr 1"];
-    N42[label="expr y"];
-    N43[label="expr y -= 1"];
-    N44[label="stmt y -= 1;"];
-    N45[label="(dummy_node)"];
-    N46[label="expr \'a: loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }"];
-    N47[label="expr z"];
-    N48[label="expr 0"];
-    N49[label="expr z == 0"];
-    N50[label="expr break"];
-    N51[label="(dummy_node)"];
-    N52[label="stmt break ;"];
-    N53[label="expr \"unreachable\""];
-    N54[label="stmt \"unreachable\";"];
-    N55[label="block { break ; \"unreachable\"; }"];
-    N56[label="expr if z == 0 { break ; \"unreachable\"; }"];
-    N57[label="stmt if z == 0 { break ; \"unreachable\"; }"];
-    N58[label="expr 1"];
-    N59[label="expr z"];
-    N60[label="expr z -= 1"];
-    N61[label="stmt z -= 1;"];
-    N62[label="block { if z == 0 { break ; \"unreachable\"; } z -= 1; }"];
-    N63[label="stmt \'a: loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }"];
-    N64[label="expr x"];
-    N65[label="expr 10"];
-    N66[label="expr x > 10"];
-    N67[label="expr continue \'a"];
-    N68[label="(dummy_node)"];
-    N69[label="stmt continue \'a ;"];
-    N70[label="expr \"unreachable\""];
-    N71[label="stmt \"unreachable\";"];
-    N72[label="block { continue \'a ; \"unreachable\"; }"];
-    N73[label="expr if x > 10 { continue \'a ; \"unreachable\"; }"];
-    N74[label="block {\l    if y == 0 { break ; \"unreachable\"; }\l    y -= 1;\l    \'a: loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l    if x > 10 { continue \'a ; \"unreachable\"; }\l}\l"];
-    N75[label="block {\l    if x == 0 { break ; \"unreachable\"; }\l    x -= 1;\l    \'a:\l        loop  {\l            if y == 0 { break ; \"unreachable\"; }\l            y -= 1;\l            \'a: loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l            if x > 10 { continue \'a ; \"unreachable\"; }\l        }\l}\l"];
-    N76[label="block {\l    let mut x = 25;\l    let mut y = 25;\l    let mut z = 25;\l    \'a:\l        loop  {\l            if x == 0 { break ; \"unreachable\"; }\l            x -= 1;\l            \'a:\l                loop  {\l                    if y == 0 { break ; \"unreachable\"; }\l                    y -= 1;\l                    \'a: loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l                    if x > 10 { continue \'a ; \"unreachable\"; }\l                }\l        }\l}\l"];
-    N77[label="expr {\l    let mut x = 25;\l    let mut y = 25;\l    let mut z = 25;\l    \'a:\l        loop  {\l            if x == 0 { break ; \"unreachable\"; }\l            x -= 1;\l            \'a:\l                loop  {\l                    if y == 0 { break ; \"unreachable\"; }\l                    y -= 1;\l                    \'a: loop  { if z == 0 { break ; \"unreachable\"; } z -= 1; }\l                    if x > 10 { continue \'a ; \"unreachable\"; }\l                }\l        }\l}\l"];
-    N0 -> N2;
-    N2 -> N3;
-    N3 -> N4;
-    N4 -> N5;
-    N5 -> N6;
-    N6 -> N7;
-    N7 -> N8;
-    N8 -> N9;
-    N9 -> N10;
-    N10 -> N11;
-    N11 -> N13;
-    N13 -> N14;
-    N14 -> N15;
-    N15 -> N16;
-    N16 -> N12;
-    N17 -> N18;
-    N18 -> N19;
-    N19 -> N20;
-    N20 -> N21;
-    N15 -> N22;
-    N21 -> N22;
-    N22 -> N23;
-    N23 -> N24;
-    N24 -> N25;
-    N25 -> N26;
-    N26 -> N27;
-    N27 -> N28;
-    N28 -> N30;
-    N30 -> N31;
-    N31 -> N32;
-    N32 -> N33;
-    N33 -> N29;
-    N34 -> N35;
-    N35 -> N36;
-    N36 -> N37;
-    N37 -> N38;
-    N32 -> N39;
-    N38 -> N39;
-    N39 -> N40;
-    N40 -> N41;
-    N41 -> N42;
-    N42 -> N43;
-    N43 -> N44;
-    N44 -> N45;
-    N45 -> N47;
-    N47 -> N48;
-    N48 -> N49;
-    N49 -> N50;
-    N50 -> N46;
-    N51 -> N52;
-    N52 -> N53;
-    N53 -> N54;
-    N54 -> N55;
-    N49 -> N56;
-    N55 -> N56;
-    N56 -> N57;
-    N57 -> N58;
-    N58 -> N59;
-    N59 -> N60;
-    N60 -> N61;
-    N61 -> N62;
-    N62 -> N45;
-    N46 -> N63;
-    N63 -> N64;
-    N64 -> N65;
-    N65 -> N66;
-    N66 -> N67;
-    N67 -> N28;
-    N68 -> N69;
-    N69 -> N70;
-    N70 -> N71;
-    N71 -> N72;
-    N66 -> N73;
-    N72 -> N73;
-    N73 -> N74;
-    N74 -> N28;
-    N29 -> N75;
-    N75 -> N11;
-    N12 -> N76;
-    N76 -> N77;
-    N77 -> N1;
-}
diff --git a/src/test/run-make/graphviz-flowgraph/f25.rs b/src/test/run-make/graphviz-flowgraph/f25.rs
deleted file mode 100644
index 2ee2e48fd10..00000000000
--- a/src/test/run-make/graphviz-flowgraph/f25.rs
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[allow(unreachable_code)]
-pub fn expr_while_25() {
-    let mut x = 25;
-    let mut y = 25;
-    let mut z = 25;
-
-    'a: loop {
-        if x == 0 { break; "unreachable"; }
-        x -= 1;
-
-        'a: loop {
-            if y == 0 { break; "unreachable"; }
-            y -= 1;
-
-            'a: loop {
-                if z == 0 { break; "unreachable"; }
-                z -= 1;
-            }
-
-            if x > 10 {
-                continue 'a;
-                "unreachable";
-            }
-        }
-    }
-}
diff --git a/src/test/run-pass/diverging-fallback-control-flow.rs b/src/test/run-pass/diverging-fallback-control-flow.rs
new file mode 100644
index 00000000000..656e90d2d52
--- /dev/null
+++ b/src/test/run-pass/diverging-fallback-control-flow.rs
@@ -0,0 +1,106 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test various cases where we permit an unconstrained variable
+// to fallback based on control-flow.
+//
+// These represent current behavior, but are pretty dubious.  I would
+// like to revisit these and potentially change them. --nmatsakis
+
+#![feature(never_type)]
+#![feature(loop_break_value)]
+
+trait BadDefault {
+    fn default() -> Self;
+}
+
+impl BadDefault for u32 {
+    fn default() -> Self {
+        0
+    }
+}
+
+impl BadDefault for ! {
+    fn default() -> ! {
+        panic!()
+    }
+}
+
+fn assignment() {
+    let x;
+
+    if true {
+        x = BadDefault::default();
+    } else {
+        x = return;
+    }
+}
+
+fn assignment_rev() {
+    let x;
+
+    if true {
+        x = return;
+    } else {
+        x = BadDefault::default();
+    }
+}
+
+fn if_then_else() {
+    let _x = if true {
+        BadDefault::default()
+    } else {
+        return;
+    };
+}
+
+fn if_then_else_rev() {
+    let _x = if true {
+        return;
+    } else {
+        BadDefault::default()
+    };
+}
+
+fn match_arm() {
+    let _x = match Ok(BadDefault::default()) {
+        Ok(v) => v,
+        Err(()) => return,
+    };
+}
+
+fn match_arm_rev() {
+    let _x = match Ok(BadDefault::default()) {
+        Err(()) => return,
+        Ok(v) => v,
+    };
+}
+
+fn loop_break() {
+    let _x = loop {
+        if false {
+            break return;
+        } else {
+            break BadDefault::default();
+        }
+    };
+}
+
+fn loop_break_rev() {
+    let _x = loop {
+        if false {
+            break return;
+        } else {
+            break BadDefault::default();
+        }
+    };
+}
+
+fn main() { }
diff --git a/src/test/run-pass/unit-fallback.rs b/src/test/run-pass/diverging-fallback-method-chain.rs
index 2babc6348e1..664a329c228 100644
--- a/src/test/run-pass/unit-fallback.rs
+++ b/src/test/run-pass/diverging-fallback-method-chain.rs
@@ -8,31 +8,20 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// Test that diverging types default to () (with feature(never_type) disabled).
+// Test a regression found when building compiler. The `produce()`
+// error type `T` winds up getting unified with result of `x.parse()`;
+// the type of the closure given to `unwrap_or_else` needs to be
+// inferred to `usize`.
 
-trait Balls: Sized {
-    fn smeg() -> Result<Self, ()>;
-}
-
-impl Balls for () {
-    fn smeg() -> Result<(), ()> { Ok(()) }
-}
-
-struct Flah;
+use std::num::ParseIntError;
 
-impl Flah {
-    fn flah<T: Balls>(&self) -> Result<T, ()> {
-        T::smeg()
-    }
-}
-
-fn doit() -> Result<(), ()> {
-    // The type of _ is unconstrained here and should default to ()
-    let _ = try!(Flah.flah());
-    Ok(())
+fn produce<T>() -> Result<&'static str, T> {
+    Ok("22")
 }
 
 fn main() {
-    let _ = doit();
+    let x: usize = produce()
+        .and_then(|x| x.parse())
+        .unwrap_or_else(|_| panic!());
+    println!("{}", x);
 }
-
diff --git a/src/test/run-pass/diverging-fallback-option.rs b/src/test/run-pass/diverging-fallback-option.rs
new file mode 100644
index 00000000000..49f90e7c91f
--- /dev/null
+++ b/src/test/run-pass/diverging-fallback-option.rs
@@ -0,0 +1,22 @@
+// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(warnings)]
+
+// Here the type of `c` is `Option<?T>`, where `?T` is unconstrained.
+// Because there is data-flow from the `{ return; }` block, which
+// diverges and hence has type `!`, into `c`, we will default `?T` to
+// `!`, and hence this code compiles rather than failing and requiring
+// a type annotation.
+
+fn main() {
+    let c = Some({ return; });
+    c.unwrap();
+}
diff --git a/src/test/run-pass/issue-39808.rs b/src/test/run-pass/issue-39808.rs
new file mode 100644
index 00000000000..91c70d76eef
--- /dev/null
+++ b/src/test/run-pass/issue-39808.rs
@@ -0,0 +1,26 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unreachable_code)]
+
+// Regression test for #39808. The type parameter of `Owned` was
+// considered to be "unconstrained" because the type resulting from
+// `format!` (`String`) was not being propagated upward, owing to the
+// fact that the expression diverges.
+
+use std::borrow::Cow;
+
+fn main() {
+    let _ = if false {
+        Cow::Owned(format!("{:?}", panic!()))
+    } else {
+        Cow::Borrowed("")
+    };
+}
diff --git a/src/test/run-make/graphviz-flowgraph/f08.rs b/src/test/ui/loop-break-value-no-repeat.rs
index 6ba7b03d54d..790f796fae0 100644
--- a/src/test/run-make/graphviz-flowgraph/f08.rs
+++ b/src/test/ui/loop-break-value-no-repeat.rs
@@ -1,4 +1,4 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,9 +8,18 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-pub fn expr_if_onearm_8() {
-    let x = 8; let _y;
-    if x > 88 {
-        _y = 888;
+#![feature(loop_break_value)]
+#![allow(unused_variables)]
+
+use std::ptr;
+
+// Test that we only report **one** error here and that is that
+// `break` with an expression is illegal in this context. In
+// particular, we don't report any mismatched types error, which is
+// besides the point.
+
+fn main() {
+    for _ in &[1,2,3] {
+        break 22
     }
 }
diff --git a/src/test/ui/loop-break-value-no-repeat.stderr b/src/test/ui/loop-break-value-no-repeat.stderr
new file mode 100644
index 00000000000..0d99abd3907
--- /dev/null
+++ b/src/test/ui/loop-break-value-no-repeat.stderr
@@ -0,0 +1,8 @@
+error[E0571]: `break` with value from a `for` loop
+  --> $DIR/loop-break-value-no-repeat.rs:23:9
+   |
+23 |         break 22
+   |         ^^^^^^^^ can only break with a value inside `loop`
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/reachable/README.md b/src/test/ui/reachable/README.md
new file mode 100644
index 00000000000..8bed5fba7a2
--- /dev/null
+++ b/src/test/ui/reachable/README.md
@@ -0,0 +1,7 @@
+A variety of tests around reachability. These tests in general check
+two things:
+
+- that we get unreachable code warnings in reasonable locations;
+- that we permit coercions **into** `!` from expressions which
+  diverge, where an expression "diverges" if it must execute some
+  subexpression of type `!`, or it has type `!` itself.
diff --git a/src/test/run-make/graphviz-flowgraph/f10.rs b/src/test/ui/reachable/expr_add.rs
index 0ca7cc5ee86..87d017adf68 100644
--- a/src/test/run-make/graphviz-flowgraph/f10.rs
+++ b/src/test/ui/reachable/expr_add.rs
@@ -1,4 +1,4 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,9 +8,21 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-pub fn expr_while_10() {
-    let mut x = 10;
-    while x > 0 {
-        x -= 1;
+#![feature(never_type)]
+#![allow(unused_variables)]
+#![deny(unreachable_code)]
+
+use std::ops;
+
+struct Foo;
+
+impl ops::Add<!> for Foo {
+    type Output = !;
+    fn add(self, rhs: !) -> ! {
+        unimplemented!()
     }
 }
+
+fn main() {
+    let x = Foo + return;
+}
diff --git a/src/test/ui/reachable/expr_add.stderr b/src/test/ui/reachable/expr_add.stderr
new file mode 100644
index 00000000000..1a2cc252051
--- /dev/null
+++ b/src/test/ui/reachable/expr_add.stderr
@@ -0,0 +1,14 @@
+error: unreachable expression
+  --> $DIR/expr_add.rs:27:13
+   |
+27 |     let x = Foo + return;
+   |             ^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_add.rs:13:9
+   |
+13 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/run-make/graphviz-flowgraph/f02.rs b/src/test/ui/reachable/expr_again.rs
index f7fe1266198..cdbdb8dc0db 100644
--- a/src/test/run-make/graphviz-flowgraph/f02.rs
+++ b/src/test/ui/reachable/expr_again.rs
@@ -1,4 +1,4 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,6 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-pub fn decl_x_2() {
-    let _x : isize;
+#![feature(box_syntax)]
+#![allow(unused_variables)]
+#![deny(unreachable_code)]
+
+fn main() {
+    let x = loop {
+        continue;
+        println!("hi");
+    };
 }
diff --git a/src/test/ui/reachable/expr_again.stderr b/src/test/ui/reachable/expr_again.stderr
new file mode 100644
index 00000000000..bf4e4dc4711
--- /dev/null
+++ b/src/test/ui/reachable/expr_again.stderr
@@ -0,0 +1,15 @@
+error: unreachable statement
+  --> $DIR/expr_again.rs:18:9
+   |
+18 |         println!("hi");
+   |         ^^^^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_again.rs:13:9
+   |
+13 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+   = note: this error originates in a macro outside of the current crate
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/reachable/expr_andand.rs b/src/test/ui/reachable/expr_andand.rs
new file mode 100644
index 00000000000..af404d03097
--- /dev/null
+++ b/src/test/ui/reachable/expr_andand.rs
@@ -0,0 +1,21 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+
+fn foo() {
+    // No error here.
+    let x = false && (return);
+    println!("I am not dead.");
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_andand.stderr b/src/test/ui/reachable/expr_andand.stderr
new file mode 100644
index 00000000000..e69de29bb2d
--- /dev/null
+++ b/src/test/ui/reachable/expr_andand.stderr
diff --git a/src/test/ui/reachable/expr_array.rs b/src/test/ui/reachable/expr_array.rs
new file mode 100644
index 00000000000..00e8be07725
--- /dev/null
+++ b/src/test/ui/reachable/expr_array.rs
@@ -0,0 +1,28 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+#![feature(type_ascription)]
+
+fn a() {
+    // the `22` is unreachable:
+    let x: [usize; 2] = [return, 22];
+}
+
+fn b() {
+    // the `array is unreachable:
+    let x: [usize; 2] = [22, return];
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_array.stderr b/src/test/ui/reachable/expr_array.stderr
new file mode 100644
index 00000000000..f8dbdb5f8bb
--- /dev/null
+++ b/src/test/ui/reachable/expr_array.stderr
@@ -0,0 +1,20 @@
+error: unreachable expression
+  --> $DIR/expr_array.rs:20:34
+   |
+20 |     let x: [usize; 2] = [return, 22];
+   |                                  ^^
+   |
+note: lint level defined here
+  --> $DIR/expr_array.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: unreachable expression
+  --> $DIR/expr_array.rs:25:25
+   |
+25 |     let x: [usize; 2] = [22, return];
+   |                         ^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/ui/reachable/expr_assign.rs b/src/test/ui/reachable/expr_assign.rs
new file mode 100644
index 00000000000..1b9357013d2
--- /dev/null
+++ b/src/test/ui/reachable/expr_assign.rs
@@ -0,0 +1,39 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+
+fn foo() {
+    // No error here.
+    let x;
+    x = return;
+}
+
+fn bar() {
+    use std::ptr;
+    let p: *mut ! = ptr::null_mut::<!>();
+    unsafe {
+        // Here we consider the `return` unreachable because
+        // "evaluating" the `*p` has type `!`. This is somewhat
+        // dubious, I suppose.
+        *p = return;
+    }
+}
+
+fn baz() {
+    let mut i = 0;
+    *{return; &mut i} = 22;
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_assign.stderr b/src/test/ui/reachable/expr_assign.stderr
new file mode 100644
index 00000000000..807f6a1c1d5
--- /dev/null
+++ b/src/test/ui/reachable/expr_assign.stderr
@@ -0,0 +1,26 @@
+error: unreachable expression
+  --> $DIR/expr_assign.rs:20:5
+   |
+20 |     x = return;
+   |     ^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_assign.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: unreachable expression
+  --> $DIR/expr_assign.rs:30:14
+   |
+30 |         *p = return;
+   |              ^^^^^^
+
+error: unreachable expression
+  --> $DIR/expr_assign.rs:36:15
+   |
+36 |     *{return; &mut i} = 22;
+   |               ^^^^^^
+
+error: aborting due to 3 previous errors
+
diff --git a/src/test/ui/reachable/expr_block.rs b/src/test/ui/reachable/expr_block.rs
new file mode 100644
index 00000000000..093589b4dc8
--- /dev/null
+++ b/src/test/ui/reachable/expr_block.rs
@@ -0,0 +1,41 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+
+fn a() {
+    // Here the tail expression is considered unreachable:
+    let x = {
+        return;
+        22
+    };
+}
+
+fn b() {
+    // Here the `x` assignment is considered unreachable, not the block:
+    let x = {
+        return;
+    };
+}
+
+fn c() {
+    // Here the `println!` is unreachable:
+    let x = {
+        return;
+        println!("foo");
+        22
+    };
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_block.stderr b/src/test/ui/reachable/expr_block.stderr
new file mode 100644
index 00000000000..542ce1c3fd9
--- /dev/null
+++ b/src/test/ui/reachable/expr_block.stderr
@@ -0,0 +1,22 @@
+error: unreachable expression
+  --> $DIR/expr_block.rs:21:9
+   |
+21 |         22
+   |         ^^
+   |
+note: lint level defined here
+  --> $DIR/expr_block.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: unreachable statement
+  --> $DIR/expr_block.rs:36:9
+   |
+36 |         println!("foo");
+   |         ^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in a macro outside of the current crate
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/run-make/graphviz-flowgraph/f00.rs b/src/test/ui/reachable/expr_box.rs
index 4e7fc7ea9b0..6509b608335 100644
--- a/src/test/run-make/graphviz-flowgraph/f00.rs
+++ b/src/test/ui/reachable/expr_box.rs
@@ -1,4 +1,4 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,6 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-pub fn empty_0() {
+#![feature(box_syntax)]
+#![allow(unused_variables)]
+#![deny(unreachable_code)]
 
+fn main() {
+    let x = box return;
+    println!("hi");
 }
diff --git a/src/test/ui/reachable/expr_box.stderr b/src/test/ui/reachable/expr_box.stderr
new file mode 100644
index 00000000000..78ba231cef9
--- /dev/null
+++ b/src/test/ui/reachable/expr_box.stderr
@@ -0,0 +1,14 @@
+error: unreachable expression
+  --> $DIR/expr_box.rs:16:13
+   |
+16 |     let x = box return;
+   |             ^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_box.rs:13:9
+   |
+13 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/reachable/expr_call.rs b/src/test/ui/reachable/expr_call.rs
new file mode 100644
index 00000000000..8d9f303df7f
--- /dev/null
+++ b/src/test/ui/reachable/expr_call.rs
@@ -0,0 +1,31 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+
+fn foo(x: !, y: usize) { }
+
+fn bar(x: !) { }
+
+fn a() {
+    // the `22` is unreachable:
+    foo(return, 22);
+}
+
+fn b() {
+    // the call is unreachable:
+    bar(return);
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_call.stderr b/src/test/ui/reachable/expr_call.stderr
new file mode 100644
index 00000000000..5526827f59f
--- /dev/null
+++ b/src/test/ui/reachable/expr_call.stderr
@@ -0,0 +1,20 @@
+error: unreachable expression
+  --> $DIR/expr_call.rs:23:17
+   |
+23 |     foo(return, 22);
+   |                 ^^
+   |
+note: lint level defined here
+  --> $DIR/expr_call.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: unreachable expression
+  --> $DIR/expr_call.rs:28:5
+   |
+28 |     bar(return);
+   |     ^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/ui/reachable/expr_cast.rs b/src/test/ui/reachable/expr_cast.rs
new file mode 100644
index 00000000000..926ef864ebf
--- /dev/null
+++ b/src/test/ui/reachable/expr_cast.rs
@@ -0,0 +1,23 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+#![feature(type_ascription)]
+
+fn a() {
+    // the cast is unreachable:
+    let x = {return} as !;
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_cast.stderr b/src/test/ui/reachable/expr_cast.stderr
new file mode 100644
index 00000000000..a22300dcc13
--- /dev/null
+++ b/src/test/ui/reachable/expr_cast.stderr
@@ -0,0 +1,14 @@
+error: unreachable expression
+  --> $DIR/expr_cast.rs:20:13
+   |
+20 |     let x = {return} as !;
+   |             ^^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_cast.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/reachable/expr_if.rs b/src/test/ui/reachable/expr_if.rs
new file mode 100644
index 00000000000..2a265e772f3
--- /dev/null
+++ b/src/test/ui/reachable/expr_if.rs
@@ -0,0 +1,41 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+
+fn foo() {
+    if {return} {
+        println!("Hello, world!");
+    }
+}
+
+fn bar() {
+    if {true} {
+        return;
+    }
+    println!("I am not dead.");
+}
+
+fn baz() {
+    if {true} {
+        return;
+    } else {
+        return;
+    }
+    // As the next action to be taken after the if arms, we should
+    // report the `println!` as unreachable:
+    println!("But I am.");
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_if.stderr b/src/test/ui/reachable/expr_if.stderr
new file mode 100644
index 00000000000..2cf17474f6e
--- /dev/null
+++ b/src/test/ui/reachable/expr_if.stderr
@@ -0,0 +1,15 @@
+error: unreachable statement
+  --> $DIR/expr_if.rs:38:5
+   |
+38 |     println!("But I am.");
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_if.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+   = note: this error originates in a macro outside of the current crate
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/reachable/expr_loop.rs b/src/test/ui/reachable/expr_loop.rs
new file mode 100644
index 00000000000..3ed4b2dcf0c
--- /dev/null
+++ b/src/test/ui/reachable/expr_loop.rs
@@ -0,0 +1,44 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+
+fn a() {
+    loop { return; }
+    println!("I am dead.");
+}
+
+fn b() {
+    loop {
+        break;
+    }
+    println!("I am not dead.");
+}
+
+fn c() {
+    loop { return; }
+    println!("I am dead.");
+}
+
+fn d() {
+    'outer: loop { loop { break 'outer; } }
+    println!("I am not dead.");
+}
+
+fn e() {
+    loop { 'middle: loop { loop { break 'middle; } } }
+    println!("I am dead.");
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_loop.stderr b/src/test/ui/reachable/expr_loop.stderr
new file mode 100644
index 00000000000..6e98e754c54
--- /dev/null
+++ b/src/test/ui/reachable/expr_loop.stderr
@@ -0,0 +1,31 @@
+error: unreachable statement
+  --> $DIR/expr_loop.rs:19:5
+   |
+19 |     println!("I am dead.");
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_loop.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+   = note: this error originates in a macro outside of the current crate
+
+error: unreachable statement
+  --> $DIR/expr_loop.rs:31:5
+   |
+31 |     println!("I am dead.");
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in a macro outside of the current crate
+
+error: unreachable statement
+  --> $DIR/expr_loop.rs:41:5
+   |
+41 |     println!("I am dead.");
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in a macro outside of the current crate
+
+error: aborting due to 3 previous errors
+
diff --git a/src/test/ui/reachable/expr_match.rs b/src/test/ui/reachable/expr_match.rs
new file mode 100644
index 00000000000..23bdcc035b2
--- /dev/null
+++ b/src/test/ui/reachable/expr_match.rs
@@ -0,0 +1,54 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+
+fn a() {
+    // The match is considered unreachable here, because the `return`
+    // diverges:
+    match {return} { }
+}
+
+fn b() {
+    match () { () => return }
+    println!("I am dead");
+}
+
+fn c() {
+    match () { () if false => return, () => () }
+    println!("I am not dead");
+}
+
+fn d() {
+    match () { () if false => return, () => return }
+    println!("I am dead");
+}
+
+fn e() {
+    // Here the compiler fails to figure out that the `println` is dead.
+    match () { () if return => (), () => return }
+    println!("I am dead");
+}
+
+fn f() {
+    match Some(()) { None => (), Some(()) => return }
+    println!("I am not dead");
+}
+
+fn g() {
+    match Some(()) { None => return, Some(()) => () }
+    println!("I am not dead");
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_match.stderr b/src/test/ui/reachable/expr_match.stderr
new file mode 100644
index 00000000000..f5857a5b345
--- /dev/null
+++ b/src/test/ui/reachable/expr_match.stderr
@@ -0,0 +1,30 @@
+error: unreachable expression
+  --> $DIR/expr_match.rs:20:5
+   |
+20 |     match {return} { }
+   |     ^^^^^^^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_match.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: unreachable statement
+  --> $DIR/expr_match.rs:25:5
+   |
+25 |     println!("I am dead");
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in a macro outside of the current crate
+
+error: unreachable statement
+  --> $DIR/expr_match.rs:35:5
+   |
+35 |     println!("I am dead");
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in a macro outside of the current crate
+
+error: aborting due to 3 previous errors
+
diff --git a/src/test/ui/reachable/expr_method.rs b/src/test/ui/reachable/expr_method.rs
new file mode 100644
index 00000000000..f1d979d7df7
--- /dev/null
+++ b/src/test/ui/reachable/expr_method.rs
@@ -0,0 +1,34 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+
+struct Foo;
+
+impl Foo {
+    fn foo(&self, x: !, y: usize) { }
+    fn bar(&self, x: !) { }
+}
+
+fn a() {
+    // the `22` is unreachable:
+    Foo.foo(return, 22);
+}
+
+fn b() {
+    // the call is unreachable:
+    Foo.bar(return);
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_method.stderr b/src/test/ui/reachable/expr_method.stderr
new file mode 100644
index 00000000000..177d4352a37
--- /dev/null
+++ b/src/test/ui/reachable/expr_method.stderr
@@ -0,0 +1,20 @@
+error: unreachable expression
+  --> $DIR/expr_method.rs:26:21
+   |
+26 |     Foo.foo(return, 22);
+   |                     ^^
+   |
+note: lint level defined here
+  --> $DIR/expr_method.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: unreachable expression
+  --> $DIR/expr_method.rs:31:5
+   |
+31 |     Foo.bar(return);
+   |     ^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/ui/reachable/expr_oror.rs b/src/test/ui/reachable/expr_oror.rs
new file mode 100644
index 00000000000..d01304d4034
--- /dev/null
+++ b/src/test/ui/reachable/expr_oror.rs
@@ -0,0 +1,20 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+
+fn foo() {
+    let x = false || (return);
+    println!("I am not dead.");
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_oror.stderr b/src/test/ui/reachable/expr_oror.stderr
new file mode 100644
index 00000000000..e69de29bb2d
--- /dev/null
+++ b/src/test/ui/reachable/expr_oror.stderr
diff --git a/src/test/ui/reachable/expr_repeat.rs b/src/test/ui/reachable/expr_repeat.rs
new file mode 100644
index 00000000000..6078d6d5bde
--- /dev/null
+++ b/src/test/ui/reachable/expr_repeat.rs
@@ -0,0 +1,23 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+#![feature(type_ascription)]
+
+fn a() {
+    // the repeat is unreachable:
+    let x: [usize; 2] = [return; 2];
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_repeat.stderr b/src/test/ui/reachable/expr_repeat.stderr
new file mode 100644
index 00000000000..19afc5dd7b5
--- /dev/null
+++ b/src/test/ui/reachable/expr_repeat.stderr
@@ -0,0 +1,14 @@
+error: unreachable expression
+  --> $DIR/expr_repeat.rs:20:25
+   |
+20 |     let x: [usize; 2] = [return; 2];
+   |                         ^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_repeat.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/reachable/expr_return.rs b/src/test/ui/reachable/expr_return.rs
new file mode 100644
index 00000000000..c640ca06630
--- /dev/null
+++ b/src/test/ui/reachable/expr_return.rs
@@ -0,0 +1,24 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+#![feature(type_ascription)]
+
+fn a() {
+    // Here we issue that the "2nd-innermost" return is unreachable,
+    // but we stop there.
+    let x = {return {return {return;}}};
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_return.stderr b/src/test/ui/reachable/expr_return.stderr
new file mode 100644
index 00000000000..3eb70a4dd7c
--- /dev/null
+++ b/src/test/ui/reachable/expr_return.stderr
@@ -0,0 +1,14 @@
+error: unreachable expression
+  --> $DIR/expr_return.rs:21:22
+   |
+21 |     let x = {return {return {return;}}};
+   |                      ^^^^^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_return.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/reachable/expr_struct.rs b/src/test/ui/reachable/expr_struct.rs
new file mode 100644
index 00000000000..09e31819279
--- /dev/null
+++ b/src/test/ui/reachable/expr_struct.rs
@@ -0,0 +1,43 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+#![feature(type_ascription)]
+
+struct Foo {
+    a: usize,
+    b: usize,
+}
+
+fn a() {
+    // struct expr is unreachable:
+    let x = Foo { a: 22, b: 33, ..return };
+}
+
+fn b() {
+    // the `33` is unreachable:
+    let x = Foo { a: return, b: 33, ..return };
+}
+
+fn c() {
+    // the `..return` is unreachable:
+    let x = Foo { a: 22, b: return, ..return };
+}
+
+fn d() {
+    // the struct expr is unreachable:
+    let x = Foo { a: 22, b: return };
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_struct.stderr b/src/test/ui/reachable/expr_struct.stderr
new file mode 100644
index 00000000000..4b7ac660413
--- /dev/null
+++ b/src/test/ui/reachable/expr_struct.stderr
@@ -0,0 +1,32 @@
+error: unreachable expression
+  --> $DIR/expr_struct.rs:25:13
+   |
+25 |     let x = Foo { a: 22, b: 33, ..return };
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_struct.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: unreachable expression
+  --> $DIR/expr_struct.rs:30:33
+   |
+30 |     let x = Foo { a: return, b: 33, ..return };
+   |                                 ^^
+
+error: unreachable expression
+  --> $DIR/expr_struct.rs:35:39
+   |
+35 |     let x = Foo { a: 22, b: return, ..return };
+   |                                       ^^^^^^
+
+error: unreachable expression
+  --> $DIR/expr_struct.rs:40:13
+   |
+40 |     let x = Foo { a: 22, b: return };
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 4 previous errors
+
diff --git a/src/test/ui/reachable/expr_tup.rs b/src/test/ui/reachable/expr_tup.rs
new file mode 100644
index 00000000000..7c75296de6c
--- /dev/null
+++ b/src/test/ui/reachable/expr_tup.rs
@@ -0,0 +1,28 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+#![feature(type_ascription)]
+
+fn a() {
+    // the `2` is unreachable:
+    let x: (usize, usize) = (return, 2);
+}
+
+fn b() {
+    // the tuple is unreachable:
+    let x: (usize, usize) = (2, return);
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_tup.stderr b/src/test/ui/reachable/expr_tup.stderr
new file mode 100644
index 00000000000..63f477fd0c3
--- /dev/null
+++ b/src/test/ui/reachable/expr_tup.stderr
@@ -0,0 +1,20 @@
+error: unreachable expression
+  --> $DIR/expr_tup.rs:20:38
+   |
+20 |     let x: (usize, usize) = (return, 2);
+   |                                      ^
+   |
+note: lint level defined here
+  --> $DIR/expr_tup.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: unreachable expression
+  --> $DIR/expr_tup.rs:25:29
+   |
+25 |     let x: (usize, usize) = (2, return);
+   |                             ^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/ui/reachable/expr_type.rs b/src/test/ui/reachable/expr_type.rs
new file mode 100644
index 00000000000..2fa277c382e
--- /dev/null
+++ b/src/test/ui/reachable/expr_type.rs
@@ -0,0 +1,23 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+#![feature(type_ascription)]
+
+fn a() {
+    // the cast is unreachable:
+    let x = {return}: !;
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_type.stderr b/src/test/ui/reachable/expr_type.stderr
new file mode 100644
index 00000000000..6ed79974ccb
--- /dev/null
+++ b/src/test/ui/reachable/expr_type.stderr
@@ -0,0 +1,14 @@
+error: unreachable expression
+  --> $DIR/expr_type.rs:20:13
+   |
+20 |     let x = {return}: !;
+   |             ^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_type.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/reachable/expr_unary.rs b/src/test/ui/reachable/expr_unary.rs
new file mode 100644
index 00000000000..57901fbaa7c
--- /dev/null
+++ b/src/test/ui/reachable/expr_unary.rs
@@ -0,0 +1,21 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+
+fn foo() {
+    let x: ! = ! { return; 22 };
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_unary.stderr b/src/test/ui/reachable/expr_unary.stderr
new file mode 100644
index 00000000000..11172652d84
--- /dev/null
+++ b/src/test/ui/reachable/expr_unary.stderr
@@ -0,0 +1,8 @@
+error: cannot apply unary operator `!` to type `!`
+  --> $DIR/expr_unary.rs:18:16
+   |
+18 |     let x: ! = ! { return; 22 };
+   |                ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/reachable/expr_while.rs b/src/test/ui/reachable/expr_while.rs
new file mode 100644
index 00000000000..7dcd609fbc8
--- /dev/null
+++ b/src/test/ui/reachable/expr_while.rs
@@ -0,0 +1,38 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+#![allow(dead_code)]
+#![deny(unreachable_code)]
+#![feature(never_type)]
+
+fn foo() {
+    while {return} {
+        println!("Hello, world!");
+    }
+}
+
+fn bar() {
+    while {true} {
+        return;
+    }
+    println!("I am not dead.");
+}
+
+fn baz() {
+    // Here, we cite the `while` loop as dead.
+    while {return} {
+        println!("I am dead.");
+    }
+    println!("I am, too.");
+}
+
+fn main() { }
diff --git a/src/test/ui/reachable/expr_while.stderr b/src/test/ui/reachable/expr_while.stderr
new file mode 100644
index 00000000000..066cfc86c64
--- /dev/null
+++ b/src/test/ui/reachable/expr_while.stderr
@@ -0,0 +1,31 @@
+error: unreachable statement
+  --> $DIR/expr_while.rs:19:9
+   |
+19 |         println!("Hello, world!");
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/expr_while.rs:14:9
+   |
+14 | #![deny(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+   = note: this error originates in a macro outside of the current crate
+
+error: unreachable statement
+  --> $DIR/expr_while.rs:33:9
+   |
+33 |         println!("I am dead.");
+   |         ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in a macro outside of the current crate
+
+error: unreachable statement
+  --> $DIR/expr_while.rs:35:5
+   |
+35 |     println!("I am, too.");
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in a macro outside of the current crate
+
+error: aborting due to 3 previous errors
+
diff --git a/src/test/ui/resolve/token-error-correct-3.stderr b/src/test/ui/resolve/token-error-correct-3.stderr
index 56e36889575..5be23d8ca48 100644
--- a/src/test/ui/resolve/token-error-correct-3.stderr
+++ b/src/test/ui/resolve/token-error-correct-3.stderr
@@ -36,10 +36,6 @@ error[E0308]: mismatched types
    |
    = note: expected type `()`
               found type `std::result::Result<bool, std::io::Error>`
-   = help: here are some functions which might fulfill your needs:
-           - .unwrap()
-           - .unwrap_err()
-           - .unwrap_or_default()
 
 error: aborting due to previous error