diff --git a/src/bootstrap/bootstrap.py b/src/bootstrap/bootstrap.py
index 9f9d3471640ff..526beb41aae5b 100644
--- a/src/bootstrap/bootstrap.py
+++ b/src/bootstrap/bootstrap.py
@@ -600,16 +600,19 @@ def bootstrap():
 
 def main():
     start_time = time()
+    help_triggered = ('-h' in sys.argv) or ('--help' in sys.argv) or (len(sys.argv) == 1)
     try:
         bootstrap()
-        print("Build completed successfully in %s" % format_build_time(time() - start_time))
+        if not help_triggered:
+            print("Build completed successfully in %s" % format_build_time(time() - start_time))
     except (SystemExit, KeyboardInterrupt) as e:
         if hasattr(e, 'code') and isinstance(e.code, int):
             exit_code = e.code
         else:
             exit_code = 1
             print(e)
-        print("Build completed unsuccessfully in %s" % format_build_time(time() - start_time))
+        if not help_triggered:
+            print("Build completed unsuccessfully in %s" % format_build_time(time() - start_time))
         sys.exit(exit_code)
 
 if __name__ == '__main__':
diff --git a/src/bootstrap/clean.rs b/src/bootstrap/clean.rs
index e9547ee42d077..308a0ab3076dd 100644
--- a/src/bootstrap/clean.rs
+++ b/src/bootstrap/clean.rs
@@ -44,26 +44,25 @@ pub fn clean(build: &Build) {
 }
 
 fn rm_rf(path: &Path) {
-    if !path.exists() {
-        return
-    }
-    if path.is_file() {
-        return do_op(path, "remove file", |p| fs::remove_file(p));
-    }
-
-    for file in t!(fs::read_dir(path)) {
-        let file = t!(file).path();
+    match path.symlink_metadata() {
+        Err(e) => {
+            if e.kind() == ErrorKind::NotFound {
+                return;
+            }
+            panic!("failed to get metadata for file {}: {}", path.display(), e);
+        },
+        Ok(metadata) => {
+            if metadata.file_type().is_file() || metadata.file_type().is_symlink() {
+                do_op(path, "remove file", |p| fs::remove_file(p));
+                return;
+            }
 
-        if file.is_dir() {
-            rm_rf(&file);
-        } else {
-            // On windows we can't remove a readonly file, and git will
-            // often clone files as readonly. As a result, we have some
-            // special logic to remove readonly files on windows.
-            do_op(&file, "remove file", |p| fs::remove_file(p));
-        }
-    }
-    do_op(path, "remove dir", |p| fs::remove_dir(p));
+            for file in t!(fs::read_dir(path)) {
+                rm_rf(&t!(file).path());
+            }
+            do_op(path, "remove dir", |p| fs::remove_dir(p));
+        },
+    };
 }
 
 fn do_op<F>(path: &Path, desc: &str, mut f: F)
@@ -71,9 +70,12 @@ fn do_op<F>(path: &Path, desc: &str, mut f: F)
 {
     match f(path) {
         Ok(()) => {}
+        // On windows we can't remove a readonly file, and git will often clone files as readonly.
+        // As a result, we have some special logic to remove readonly files on windows.
+        // This is also the reason that we can't use things like fs::remove_dir_all().
         Err(ref e) if cfg!(windows) &&
                       e.kind() == ErrorKind::PermissionDenied => {
-            let mut p = t!(path.metadata()).permissions();
+            let mut p = t!(path.symlink_metadata()).permissions();
             p.set_readonly(false);
             t!(fs::set_permissions(path, p));
             f(path).unwrap_or_else(|e| {
diff --git a/src/bootstrap/flags.rs b/src/bootstrap/flags.rs
index b55f3d710ca7b..a1466d68a135a 100644
--- a/src/bootstrap/flags.rs
+++ b/src/bootstrap/flags.rs
@@ -18,7 +18,7 @@ use std::fs;
 use std::path::PathBuf;
 use std::process;
 
-use getopts::{Matches, Options};
+use getopts::Options;
 
 use Build;
 use config::Config;
@@ -75,7 +75,22 @@ pub enum Subcommand {
 
 impl Flags {
     pub fn parse(args: &[String]) -> Flags {
+        let mut extra_help = String::new();
+        let mut subcommand_help = format!("\
+Usage: x.py <subcommand> [options] [<paths>...]
+
+Subcommands:
+    build       Compile either the compiler or libraries
+    test        Build and run some test suites
+    bench       Build and run some benchmarks
+    doc         Build documentation
+    clean       Clean out build directories
+    dist        Build and/or install distribution artifacts
+
+To learn more about a subcommand, run `./x.py <subcommand> -h`");
+
         let mut opts = Options::new();
+        // Options common to all subcommands
         opts.optflagmulti("v", "verbose", "use verbose output (-vv for very verbose)");
         opts.optflag("i", "incremental", "use incremental compilation");
         opts.optopt("", "config", "TOML configuration file for build", "FILE");
@@ -89,21 +104,83 @@ impl Flags {
         opts.optopt("j", "jobs", "number of jobs to run in parallel", "JOBS");
         opts.optflag("h", "help", "print this help message");
 
-        let usage = |n, opts: &Options| -> ! {
-            let command = args.get(0).map(|s| &**s);
-            let brief = format!("Usage: x.py {} [options] [<args>...]",
-                                command.unwrap_or("<command>"));
+        // fn usage()
+        let usage = |exit_code: i32, opts: &Options, subcommand_help: &str, extra_help: &str| -> ! {
+            println!("{}", opts.usage(subcommand_help));
+            if !extra_help.is_empty() {
+                println!("{}", extra_help);
+            }
+            process::exit(exit_code);
+        };
+
+        // We can't use getopt to parse the options until we have completed specifying which
+        // options are valid, but under the current implementation, some options are conditional on
+        // the subcommand. Therefore we must manually identify the subcommand first, so that we can
+        // complete the definition of the options.  Then we can use the getopt::Matches object from
+        // there on out.
+        let mut possible_subcommands = args.iter().collect::<Vec<_>>();
+        possible_subcommands.retain(|&s|
+                                           (s == "build")
+                                        || (s == "test")
+                                        || (s == "bench")
+                                        || (s == "doc")
+                                        || (s == "clean")
+                                        || (s == "dist"));
+        let subcommand = match possible_subcommands.first() {
+            Some(s) => s,
+            None => {
+                // No subcommand -- show the general usage and subcommand help
+                println!("{}\n", subcommand_help);
+                process::exit(0);
+            }
+        };
 
-            println!("{}", opts.usage(&brief));
-            match command {
-                Some("build") => {
-                    println!("\
+        // Some subcommands get extra options
+        match subcommand.as_str() {
+            "test"  => { opts.optmulti("", "test-args", "extra arguments", "ARGS"); },
+            "bench" => { opts.optmulti("", "test-args", "extra arguments", "ARGS"); },
+            "dist"  => { opts.optflag("", "install", "run installer as well"); },
+            _ => { },
+        };
+
+        // Done specifying what options are possible, so do the getopts parsing
+        let matches = opts.parse(&args[..]).unwrap_or_else(|e| {
+            // Invalid argument/option format
+            println!("\n{}\n", e);
+            usage(1, &opts, &subcommand_help, &extra_help);
+        });
+        // Extra sanity check to make sure we didn't hit this crazy corner case:
+        //
+        //     ./x.py --frobulate clean build
+        //            ^-- option  ^     ^- actual subcommand
+        //                        \_ arg to option could be mistaken as subcommand
+        let mut pass_sanity_check = true;
+        match matches.free.get(0) {
+            Some(check_subcommand) => {
+                if &check_subcommand != subcommand {
+                    pass_sanity_check = false;
+                }
+            },
+            None => {
+                pass_sanity_check = false;
+            }
+        }
+        if !pass_sanity_check {
+            println!("{}\n", subcommand_help);
+            println!("Sorry, I couldn't figure out which subcommand you were trying to specify.\n\
+                      You may need to move some options to after the subcommand.\n");
+            process::exit(1);
+        }
+        // Extra help text for some commands
+        match subcommand.as_str() {
+            "build" => {
+                subcommand_help.push_str("\n
 Arguments:
-    This subcommand accepts a number of positional arguments of directories to
-    the crates and/or artifacts to compile. For example:
+    This subcommand accepts a number of paths to directories to the crates
+    and/or artifacts to compile. For example:
 
         ./x.py build src/libcore
-        ./x.py build src/libproc_macro
+        ./x.py build src/libcore src/libproc_macro
         ./x.py build src/libstd --stage 1
 
     If no arguments are passed then the complete artifacts for that stage are
@@ -114,15 +191,13 @@ Arguments:
 
     For a quick build with a usable compile, you can pass:
 
-        ./x.py build --stage 1 src/libtest
-");
-                }
-
-                Some("test") => {
-                    println!("\
+        ./x.py build --stage 1 src/libtest");
+            }
+            "test" => {
+                subcommand_help.push_str("\n
 Arguments:
-    This subcommand accepts a number of positional arguments of directories to
-    tests that should be compiled and run. For example:
+    This subcommand accepts a number of paths to directories to tests that
+    should be compiled and run. For example:
 
         ./x.py test src/test/run-pass
         ./x.py test src/libstd --test-args hash_map
@@ -132,139 +207,90 @@ Arguments:
     compiled and tested.
 
         ./x.py test
-        ./x.py test --stage 1
-");
-                }
-
-                Some("doc") => {
-                    println!("\
+        ./x.py test --stage 1");
+            }
+            "doc" => {
+                subcommand_help.push_str("\n
 Arguments:
-    This subcommand accepts a number of positional arguments of directories of
-    documentation to build. For example:
+    This subcommand accepts a number of paths to directories of documentation
+    to build. For example:
 
         ./x.py doc src/doc/book
         ./x.py doc src/doc/nomicon
-        ./x.py doc src/libstd
+        ./x.py doc src/doc/book src/libstd
 
     If no arguments are passed then everything is documented:
 
         ./x.py doc
-        ./x.py doc --stage 1
-");
-                }
-
-                _ => {}
+        ./x.py doc --stage 1");
             }
-
-            if let Some(command) = command {
-                if command == "build" ||
-                   command == "dist" ||
-                   command == "doc" ||
-                   command == "test" ||
-                   command == "bench" ||
-                   command == "clean"  {
-                    println!("Available invocations:");
-                    if args.iter().any(|a| a == "-v") {
-                        let flags = Flags::parse(&["build".to_string()]);
-                        let mut config = Config::default();
-                        config.build = flags.build.clone();
-                        let mut build = Build::new(flags, config);
-                        metadata::build(&mut build);
-                        step::build_rules(&build).print_help(command);
-                    } else {
-                        println!("    ... elided, run `./x.py {} -h -v` to see",
-                                 command);
-                    }
-
-                    println!("");
-                }
-            }
-
-println!("\
-Subcommands:
-    build       Compile either the compiler or libraries
-    test        Build and run some test suites
-    bench       Build and run some benchmarks
-    doc         Build documentation
-    clean       Clean out build directories
-    dist        Build and/or install distribution artifacts
-
-To learn more about a subcommand, run `./x.py <command> -h`
-");
-
-            process::exit(n);
+            _ => { }
         };
-        if args.len() == 0 {
-            println!("a command must be passed");
-            usage(1, &opts);
-        }
-        let parse = |opts: &Options| {
-            let m = opts.parse(&args[1..]).unwrap_or_else(|e| {
-                println!("failed to parse options: {}", e);
-                usage(1, opts);
-            });
-            if m.opt_present("h") {
-                usage(0, opts);
+        // Get any optional paths which occur after the subcommand
+        let cwd = t!(env::current_dir());
+        let paths = matches.free[1..].iter().map(|p| cwd.join(p)).collect::<Vec<_>>();
+
+
+        // All subcommands can have an optional "Available paths" section
+        if matches.opt_present("verbose") {
+            let flags = Flags::parse(&["build".to_string()]);
+            let mut config = Config::default();
+            config.build = flags.build.clone();
+            let mut build = Build::new(flags, config);
+            metadata::build(&mut build);
+            let maybe_rules_help = step::build_rules(&build).get_help(subcommand);
+            if maybe_rules_help.is_some() {
+                extra_help.push_str(maybe_rules_help.unwrap().as_str());
             }
-            return m
-        };
+        } else {
+            extra_help.push_str(format!("Run `./x.py {} -h -v` to see a list of available paths.",
+                     subcommand).as_str());
+        }
 
-        let cwd = t!(env::current_dir());
-        let remaining_as_path = |m: &Matches| {
-            m.free.iter().map(|p| cwd.join(p)).collect::<Vec<_>>()
-        };
+        // User passed in -h/--help?
+        if matches.opt_present("help") {
+            usage(0, &opts, &subcommand_help, &extra_help);
+        }
 
-        let m: Matches;
-        let cmd = match &args[0][..] {
+        let cmd = match subcommand.as_str() {
             "build" => {
-                m = parse(&opts);
-                Subcommand::Build { paths: remaining_as_path(&m) }
-            }
-            "doc" => {
-                m = parse(&opts);
-                Subcommand::Doc { paths: remaining_as_path(&m) }
+                Subcommand::Build { paths: paths }
             }
             "test" => {
-                opts.optmulti("", "test-args", "extra arguments", "ARGS");
-                m = parse(&opts);
                 Subcommand::Test {
-                    paths: remaining_as_path(&m),
-                    test_args: m.opt_strs("test-args"),
+                    paths: paths,
+                    test_args: matches.opt_strs("test-args"),
                 }
             }
             "bench" => {
-                opts.optmulti("", "test-args", "extra arguments", "ARGS");
-                m = parse(&opts);
                 Subcommand::Bench {
-                    paths: remaining_as_path(&m),
-                    test_args: m.opt_strs("test-args"),
+                    paths: paths,
+                    test_args: matches.opt_strs("test-args"),
                 }
             }
+            "doc" => {
+                Subcommand::Doc { paths: paths }
+            }
             "clean" => {
-                m = parse(&opts);
-                if m.free.len() > 0 {
-                    println!("clean takes no arguments");
-                    usage(1, &opts);
+                if paths.len() > 0 {
+                    println!("\nclean takes no arguments\n");
+                    usage(1, &opts, &subcommand_help, &extra_help);
                 }
                 Subcommand::Clean
             }
             "dist" => {
-                opts.optflag("", "install", "run installer as well");
-                m = parse(&opts);
                 Subcommand::Dist {
-                    paths: remaining_as_path(&m),
-                    install: m.opt_present("install"),
+                    paths: paths,
+                    install: matches.opt_present("install"),
                 }
             }
-            "--help" => usage(0, &opts),
-            cmd => {
-                println!("unknown command: {}", cmd);
-                usage(1, &opts);
+            _ => {
+                usage(1, &opts, &subcommand_help, &extra_help);
             }
         };
 
 
-        let cfg_file = m.opt_str("config").map(PathBuf::from).or_else(|| {
+        let cfg_file = matches.opt_str("config").map(PathBuf::from).or_else(|| {
             if fs::metadata("config.toml").is_ok() {
                 Some(PathBuf::from("config.toml"))
             } else {
@@ -272,31 +298,29 @@ To learn more about a subcommand, run `./x.py <command> -h`
             }
         });
 
-        let mut stage = m.opt_str("stage").map(|j| j.parse().unwrap());
-
-        let incremental = m.opt_present("i");
+        let mut stage = matches.opt_str("stage").map(|j| j.parse().unwrap());
 
-        if incremental {
+        if matches.opt_present("incremental") {
             if stage.is_none() {
                 stage = Some(1);
             }
         }
 
         Flags {
-            verbose: m.opt_count("v"),
+            verbose: matches.opt_count("verbose"),
             stage: stage,
-            on_fail: m.opt_str("on-fail"),
-            keep_stage: m.opt_str("keep-stage").map(|j| j.parse().unwrap()),
-            build: m.opt_str("build").unwrap_or_else(|| {
+            on_fail: matches.opt_str("on-fail"),
+            keep_stage: matches.opt_str("keep-stage").map(|j| j.parse().unwrap()),
+            build: matches.opt_str("build").unwrap_or_else(|| {
                 env::var("BUILD").unwrap()
             }),
-            host: split(m.opt_strs("host")),
-            target: split(m.opt_strs("target")),
+            host: split(matches.opt_strs("host")),
+            target: split(matches.opt_strs("target")),
             config: cfg_file,
-            src: m.opt_str("src").map(PathBuf::from),
-            jobs: m.opt_str("jobs").map(|j| j.parse().unwrap()),
+            src: matches.opt_str("src").map(PathBuf::from),
+            jobs: matches.opt_str("jobs").map(|j| j.parse().unwrap()),
             cmd: cmd,
-            incremental: incremental,
+            incremental: matches.opt_present("incremental"),
         }
     }
 }
diff --git a/src/bootstrap/step.rs b/src/bootstrap/step.rs
index 6eb12fed5abb2..5560b5b0333c8 100644
--- a/src/bootstrap/step.rs
+++ b/src/bootstrap/step.rs
@@ -978,26 +978,25 @@ invalid rule dependency graph detected, was a rule added and maybe typo'd?
         }
     }
 
-    pub fn print_help(&self, command: &str) {
+    pub fn get_help(&self, command: &str) -> Option<String> {
         let kind = match command {
             "build" => Kind::Build,
             "doc" => Kind::Doc,
             "test" => Kind::Test,
             "bench" => Kind::Bench,
             "dist" => Kind::Dist,
-            _ => return,
+            _ => return None,
         };
         let rules = self.rules.values().filter(|r| r.kind == kind);
         let rules = rules.filter(|r| !r.path.contains("nowhere"));
         let mut rules = rules.collect::<Vec<_>>();
         rules.sort_by_key(|r| r.path);
 
-        println!("Available paths:\n");
+        let mut help_string = String::from("Available paths:\n");
         for rule in rules {
-            print!("    ./x.py {} {}", command, rule.path);
-
-            println!("");
+            help_string.push_str(format!("    ./x.py {} {}\n", command, rule.path).as_str());
         }
+        Some(help_string)
     }
 
     /// Construct the top-level build steps that we're going to be executing,
diff --git a/src/libcollections/Cargo.toml b/src/libcollections/Cargo.toml
index 02b2171a224d0..7e92404bc0d6f 100644
--- a/src/libcollections/Cargo.toml
+++ b/src/libcollections/Cargo.toml
@@ -13,8 +13,8 @@ core = { path = "../libcore" }
 std_unicode = { path = "../libstd_unicode" }
 
 [[test]]
-name = "collectionstest"
-path = "../libcollectionstest/lib.rs"
+name = "collectionstests"
+path = "../libcollections/tests/lib.rs"
 
 [[bench]]
 name = "collectionsbenches"
diff --git a/src/libcollectionstest/binary_heap.rs b/src/libcollections/tests/binary_heap.rs
similarity index 100%
rename from src/libcollectionstest/binary_heap.rs
rename to src/libcollections/tests/binary_heap.rs
diff --git a/src/libcollectionstest/btree/map.rs b/src/libcollections/tests/btree/map.rs
similarity index 100%
rename from src/libcollectionstest/btree/map.rs
rename to src/libcollections/tests/btree/map.rs
diff --git a/src/libcollectionstest/btree/mod.rs b/src/libcollections/tests/btree/mod.rs
similarity index 100%
rename from src/libcollectionstest/btree/mod.rs
rename to src/libcollections/tests/btree/mod.rs
diff --git a/src/libcollectionstest/btree/set.rs b/src/libcollections/tests/btree/set.rs
similarity index 100%
rename from src/libcollectionstest/btree/set.rs
rename to src/libcollections/tests/btree/set.rs
diff --git a/src/libcollectionstest/cow_str.rs b/src/libcollections/tests/cow_str.rs
similarity index 100%
rename from src/libcollectionstest/cow_str.rs
rename to src/libcollections/tests/cow_str.rs
diff --git a/src/libcollectionstest/fmt.rs b/src/libcollections/tests/fmt.rs
similarity index 100%
rename from src/libcollectionstest/fmt.rs
rename to src/libcollections/tests/fmt.rs
diff --git a/src/libcollectionstest/lib.rs b/src/libcollections/tests/lib.rs
similarity index 100%
rename from src/libcollectionstest/lib.rs
rename to src/libcollections/tests/lib.rs
diff --git a/src/libcollectionstest/linked_list.rs b/src/libcollections/tests/linked_list.rs
similarity index 100%
rename from src/libcollectionstest/linked_list.rs
rename to src/libcollections/tests/linked_list.rs
diff --git a/src/libcollectionstest/slice.rs b/src/libcollections/tests/slice.rs
similarity index 100%
rename from src/libcollectionstest/slice.rs
rename to src/libcollections/tests/slice.rs
diff --git a/src/libcollectionstest/str.rs b/src/libcollections/tests/str.rs
similarity index 100%
rename from src/libcollectionstest/str.rs
rename to src/libcollections/tests/str.rs
diff --git a/src/libcollectionstest/string.rs b/src/libcollections/tests/string.rs
similarity index 100%
rename from src/libcollectionstest/string.rs
rename to src/libcollections/tests/string.rs
diff --git a/src/libcollectionstest/vec.rs b/src/libcollections/tests/vec.rs
similarity index 100%
rename from src/libcollectionstest/vec.rs
rename to src/libcollections/tests/vec.rs
diff --git a/src/libcollectionstest/vec_deque.rs b/src/libcollections/tests/vec_deque.rs
similarity index 100%
rename from src/libcollectionstest/vec_deque.rs
rename to src/libcollections/tests/vec_deque.rs
diff --git a/src/libcore/Cargo.toml b/src/libcore/Cargo.toml
index e847c7fa3a0ec..5af63aa970f2c 100644
--- a/src/libcore/Cargo.toml
+++ b/src/libcore/Cargo.toml
@@ -10,8 +10,8 @@ test = false
 bench = false
 
 [[test]]
-name = "coretest"
-path = "../libcoretest/lib.rs"
+name = "coretests"
+path = "../libcore/tests/lib.rs"
 
 [[bench]]
 name = "corebenches"
diff --git a/src/libcore/num/bignum.rs b/src/libcore/num/bignum.rs
index 8904322ca48f7..b5553fb29475b 100644
--- a/src/libcore/num/bignum.rs
+++ b/src/libcore/num/bignum.rs
@@ -19,7 +19,7 @@
 //! inputs, but we don't do so to avoid the code bloat. Each bignum is still
 //! tracked for the actual usages, so it normally doesn't matter.
 
-// This module is only for dec2flt and flt2dec, and only public because of libcoretest.
+// This module is only for dec2flt and flt2dec, and only public because of coretests.
 // It is not intended to ever be stabilized.
 #![doc(hidden)]
 #![unstable(feature = "core_private_bignum",
diff --git a/src/libcore/num/diy_float.rs b/src/libcore/num/diy_float.rs
index 11eea753f93f9..6635d95155f4b 100644
--- a/src/libcore/num/diy_float.rs
+++ b/src/libcore/num/diy_float.rs
@@ -10,7 +10,7 @@
 
 //! Extended precision "soft float", for internal use only.
 
-// This module is only for dec2flt and flt2dec, and only public because of libcoretest.
+// This module is only for dec2flt and flt2dec, and only public because of coretests.
 // It is not intended to ever be stabilized.
 #![doc(hidden)]
 #![unstable(feature = "core_private_diy_float",
diff --git a/src/libcore/num/flt2dec/mod.rs b/src/libcore/num/flt2dec/mod.rs
index f6c03a59f81e4..5123e42df61ca 100644
--- a/src/libcore/num/flt2dec/mod.rs
+++ b/src/libcore/num/flt2dec/mod.rs
@@ -118,7 +118,7 @@ provide a large enough buffer and `Part` array, and to assemble the final
 string from resulting `Part`s itself.
 
 All algorithms and formatting functions are accompanied by extensive tests
-in `coretest::num::flt2dec` module. It also shows how to use individual
+in `coretests::num::flt2dec` module. It also shows how to use individual
 functions.
 
 */
diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index df343c9d45f20..f665cfdee77ae 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -90,7 +90,7 @@ impl<T: fmt::UpperHex> fmt::UpperHex for Wrapping<T> {
 
 mod wrapping;
 
-// All these modules are technically private and only exposed for libcoretest:
+// All these modules are technically private and only exposed for coretests:
 pub mod flt2dec;
 pub mod dec2flt;
 pub mod bignum;
diff --git a/src/libcoretest/any.rs b/src/libcore/tests/any.rs
similarity index 100%
rename from src/libcoretest/any.rs
rename to src/libcore/tests/any.rs
diff --git a/src/libcoretest/array.rs b/src/libcore/tests/array.rs
similarity index 100%
rename from src/libcoretest/array.rs
rename to src/libcore/tests/array.rs
diff --git a/src/libcoretest/atomic.rs b/src/libcore/tests/atomic.rs
similarity index 100%
rename from src/libcoretest/atomic.rs
rename to src/libcore/tests/atomic.rs
diff --git a/src/libcoretest/cell.rs b/src/libcore/tests/cell.rs
similarity index 100%
rename from src/libcoretest/cell.rs
rename to src/libcore/tests/cell.rs
diff --git a/src/libcoretest/char.rs b/src/libcore/tests/char.rs
similarity index 100%
rename from src/libcoretest/char.rs
rename to src/libcore/tests/char.rs
diff --git a/src/libcoretest/clone.rs b/src/libcore/tests/clone.rs
similarity index 100%
rename from src/libcoretest/clone.rs
rename to src/libcore/tests/clone.rs
diff --git a/src/libcoretest/cmp.rs b/src/libcore/tests/cmp.rs
similarity index 100%
rename from src/libcoretest/cmp.rs
rename to src/libcore/tests/cmp.rs
diff --git a/src/libcoretest/fmt/builders.rs b/src/libcore/tests/fmt/builders.rs
similarity index 100%
rename from src/libcoretest/fmt/builders.rs
rename to src/libcore/tests/fmt/builders.rs
diff --git a/src/libcoretest/fmt/float.rs b/src/libcore/tests/fmt/float.rs
similarity index 100%
rename from src/libcoretest/fmt/float.rs
rename to src/libcore/tests/fmt/float.rs
diff --git a/src/libcoretest/fmt/mod.rs b/src/libcore/tests/fmt/mod.rs
similarity index 100%
rename from src/libcoretest/fmt/mod.rs
rename to src/libcore/tests/fmt/mod.rs
diff --git a/src/libcoretest/fmt/num.rs b/src/libcore/tests/fmt/num.rs
similarity index 100%
rename from src/libcoretest/fmt/num.rs
rename to src/libcore/tests/fmt/num.rs
diff --git a/src/libcoretest/hash/mod.rs b/src/libcore/tests/hash/mod.rs
similarity index 100%
rename from src/libcoretest/hash/mod.rs
rename to src/libcore/tests/hash/mod.rs
diff --git a/src/libcoretest/hash/sip.rs b/src/libcore/tests/hash/sip.rs
similarity index 100%
rename from src/libcoretest/hash/sip.rs
rename to src/libcore/tests/hash/sip.rs
diff --git a/src/libcoretest/intrinsics.rs b/src/libcore/tests/intrinsics.rs
similarity index 100%
rename from src/libcoretest/intrinsics.rs
rename to src/libcore/tests/intrinsics.rs
diff --git a/src/libcoretest/iter.rs b/src/libcore/tests/iter.rs
similarity index 100%
rename from src/libcoretest/iter.rs
rename to src/libcore/tests/iter.rs
diff --git a/src/libcoretest/lib.rs b/src/libcore/tests/lib.rs
similarity index 100%
rename from src/libcoretest/lib.rs
rename to src/libcore/tests/lib.rs
diff --git a/src/libcoretest/mem.rs b/src/libcore/tests/mem.rs
similarity index 100%
rename from src/libcoretest/mem.rs
rename to src/libcore/tests/mem.rs
diff --git a/src/libcoretest/nonzero.rs b/src/libcore/tests/nonzero.rs
similarity index 100%
rename from src/libcoretest/nonzero.rs
rename to src/libcore/tests/nonzero.rs
diff --git a/src/libcoretest/num/bignum.rs b/src/libcore/tests/num/bignum.rs
similarity index 100%
rename from src/libcoretest/num/bignum.rs
rename to src/libcore/tests/num/bignum.rs
diff --git a/src/libcoretest/num/dec2flt/mod.rs b/src/libcore/tests/num/dec2flt/mod.rs
similarity index 100%
rename from src/libcoretest/num/dec2flt/mod.rs
rename to src/libcore/tests/num/dec2flt/mod.rs
diff --git a/src/libcoretest/num/dec2flt/parse.rs b/src/libcore/tests/num/dec2flt/parse.rs
similarity index 100%
rename from src/libcoretest/num/dec2flt/parse.rs
rename to src/libcore/tests/num/dec2flt/parse.rs
diff --git a/src/libcoretest/num/dec2flt/rawfp.rs b/src/libcore/tests/num/dec2flt/rawfp.rs
similarity index 100%
rename from src/libcoretest/num/dec2flt/rawfp.rs
rename to src/libcore/tests/num/dec2flt/rawfp.rs
diff --git a/src/libcoretest/num/flt2dec/estimator.rs b/src/libcore/tests/num/flt2dec/estimator.rs
similarity index 100%
rename from src/libcoretest/num/flt2dec/estimator.rs
rename to src/libcore/tests/num/flt2dec/estimator.rs
diff --git a/src/libcoretest/num/flt2dec/mod.rs b/src/libcore/tests/num/flt2dec/mod.rs
similarity index 100%
rename from src/libcoretest/num/flt2dec/mod.rs
rename to src/libcore/tests/num/flt2dec/mod.rs
diff --git a/src/libcoretest/num/flt2dec/strategy/dragon.rs b/src/libcore/tests/num/flt2dec/strategy/dragon.rs
similarity index 100%
rename from src/libcoretest/num/flt2dec/strategy/dragon.rs
rename to src/libcore/tests/num/flt2dec/strategy/dragon.rs
diff --git a/src/libcoretest/num/flt2dec/strategy/grisu.rs b/src/libcore/tests/num/flt2dec/strategy/grisu.rs
similarity index 100%
rename from src/libcoretest/num/flt2dec/strategy/grisu.rs
rename to src/libcore/tests/num/flt2dec/strategy/grisu.rs
diff --git a/src/libcoretest/num/i16.rs b/src/libcore/tests/num/i16.rs
similarity index 100%
rename from src/libcoretest/num/i16.rs
rename to src/libcore/tests/num/i16.rs
diff --git a/src/libcoretest/num/i32.rs b/src/libcore/tests/num/i32.rs
similarity index 100%
rename from src/libcoretest/num/i32.rs
rename to src/libcore/tests/num/i32.rs
diff --git a/src/libcoretest/num/i64.rs b/src/libcore/tests/num/i64.rs
similarity index 100%
rename from src/libcoretest/num/i64.rs
rename to src/libcore/tests/num/i64.rs
diff --git a/src/libcoretest/num/i8.rs b/src/libcore/tests/num/i8.rs
similarity index 100%
rename from src/libcoretest/num/i8.rs
rename to src/libcore/tests/num/i8.rs
diff --git a/src/libcoretest/num/int_macros.rs b/src/libcore/tests/num/int_macros.rs
similarity index 100%
rename from src/libcoretest/num/int_macros.rs
rename to src/libcore/tests/num/int_macros.rs
diff --git a/src/libcoretest/num/mod.rs b/src/libcore/tests/num/mod.rs
similarity index 100%
rename from src/libcoretest/num/mod.rs
rename to src/libcore/tests/num/mod.rs
diff --git a/src/libcoretest/num/u16.rs b/src/libcore/tests/num/u16.rs
similarity index 100%
rename from src/libcoretest/num/u16.rs
rename to src/libcore/tests/num/u16.rs
diff --git a/src/libcoretest/num/u32.rs b/src/libcore/tests/num/u32.rs
similarity index 100%
rename from src/libcoretest/num/u32.rs
rename to src/libcore/tests/num/u32.rs
diff --git a/src/libcoretest/num/u64.rs b/src/libcore/tests/num/u64.rs
similarity index 100%
rename from src/libcoretest/num/u64.rs
rename to src/libcore/tests/num/u64.rs
diff --git a/src/libcoretest/num/u8.rs b/src/libcore/tests/num/u8.rs
similarity index 100%
rename from src/libcoretest/num/u8.rs
rename to src/libcore/tests/num/u8.rs
diff --git a/src/libcoretest/num/uint_macros.rs b/src/libcore/tests/num/uint_macros.rs
similarity index 100%
rename from src/libcoretest/num/uint_macros.rs
rename to src/libcore/tests/num/uint_macros.rs
diff --git a/src/libcoretest/ops.rs b/src/libcore/tests/ops.rs
similarity index 100%
rename from src/libcoretest/ops.rs
rename to src/libcore/tests/ops.rs
diff --git a/src/libcoretest/option.rs b/src/libcore/tests/option.rs
similarity index 100%
rename from src/libcoretest/option.rs
rename to src/libcore/tests/option.rs
diff --git a/src/libcoretest/ptr.rs b/src/libcore/tests/ptr.rs
similarity index 100%
rename from src/libcoretest/ptr.rs
rename to src/libcore/tests/ptr.rs
diff --git a/src/libcoretest/result.rs b/src/libcore/tests/result.rs
similarity index 100%
rename from src/libcoretest/result.rs
rename to src/libcore/tests/result.rs
diff --git a/src/libcoretest/slice.rs b/src/libcore/tests/slice.rs
similarity index 100%
rename from src/libcoretest/slice.rs
rename to src/libcore/tests/slice.rs
diff --git a/src/libcoretest/str.rs b/src/libcore/tests/str.rs
similarity index 90%
rename from src/libcoretest/str.rs
rename to src/libcore/tests/str.rs
index b7d9ba4463d98..08daafccc5404 100644
--- a/src/libcoretest/str.rs
+++ b/src/libcore/tests/str.rs
@@ -8,4 +8,4 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// All `str` tests live in libcollectiontest::str
+// All `str` tests live in collectionstests::str
diff --git a/src/libcoretest/tuple.rs b/src/libcore/tests/tuple.rs
similarity index 100%
rename from src/libcoretest/tuple.rs
rename to src/libcore/tests/tuple.rs
diff --git a/src/librustc_resolve/macros.rs b/src/librustc_resolve/macros.rs
index 05f30f039c8f0..966cb7ee8d8d8 100644
--- a/src/librustc_resolve/macros.rs
+++ b/src/librustc_resolve/macros.rs
@@ -222,8 +222,10 @@ impl<'a> base::Resolver for Resolver<'a> {
             let name = unwrap_or!(attrs[i].name(), continue);
 
             if name == "derive" {
-                let result = attrs[i].parse_list(&self.session.parse_sess,
-                                                 |parser| parser.parse_path(PathStyle::Mod));
+                let result = attrs[i].parse_list(&self.session.parse_sess, |parser| {
+                    parser.parse_path_allowing_meta(PathStyle::Mod)
+                });
+
                 let mut traits = match result {
                     Ok(traits) => traits,
                     Err(mut e) => {
diff --git a/src/librustc_trans/mir/block.rs b/src/librustc_trans/mir/block.rs
index 226d40948c4dc..d69f31a45048d 100644
--- a/src/librustc_trans/mir/block.rs
+++ b/src/librustc_trans/mir/block.rs
@@ -762,7 +762,6 @@ impl<'a, 'tcx> MirContext<'a, 'tcx> {
             let llretty = Type::struct_(ccx, &[Type::i8p(ccx), Type::i32(ccx)], false);
             let slot = bcx.alloca(llretty, "personalityslot");
             self.llpersonalityslot = Some(slot);
-            Lifetime::Start.call(bcx, slot);
             slot
         }
     }
@@ -794,6 +793,7 @@ impl<'a, 'tcx> MirContext<'a, 'tcx> {
         let llretval = bcx.landing_pad(llretty, llpersonality, 1, self.llfn);
         bcx.set_cleanup(llretval);
         let slot = self.get_personality_slot(&bcx);
+        Lifetime::Start.call(&bcx, slot);
         bcx.store(llretval, slot, None);
         bcx.br(target_bb);
         bcx.llbb()
diff --git a/src/libsyntax/ext/derive.rs b/src/libsyntax/ext/derive.rs
index c79040424f619..e7c5d8278d977 100644
--- a/src/libsyntax/ext/derive.rs
+++ b/src/libsyntax/ext/derive.rs
@@ -26,7 +26,8 @@ pub fn collect_derives(cx: &mut ExtCtxt, attrs: &mut Vec<ast::Attribute>) -> Vec
             return true;
         }
 
-        match attr.parse_list(cx.parse_sess, |parser| parser.parse_path(PathStyle::Mod)) {
+        match attr.parse_list(cx.parse_sess,
+                              |parser| parser.parse_path_allowing_meta(PathStyle::Mod)) {
             Ok(ref traits) if traits.is_empty() => {
                 cx.span_warn(attr.span, "empty trait list in `derive`");
                 false
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 8595bfc9f79c3..0dd2c03acb654 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -1767,6 +1767,26 @@ impl<'a> Parser<'a> {
         })
     }
 
+    /// Like `parse_path`, but also supports parsing `Word` meta items into paths for back-compat.
+    /// This is used when parsing derive macro paths in `#[derive]` attributes.
+    pub fn parse_path_allowing_meta(&mut self, mode: PathStyle) -> PResult<'a, ast::Path> {
+        let meta_ident = match self.token {
+            token::Interpolated(ref nt) => match **nt {
+                token::NtMeta(ref meta) => match meta.node {
+                    ast::MetaItemKind::Word => Some(ast::Ident::with_empty_ctxt(meta.name)),
+                    _ => None,
+                },
+                _ => None,
+            },
+            _ => None,
+        };
+        if let Some(ident) = meta_ident {
+            self.bump();
+            return Ok(ast::Path::from_ident(self.prev_span, ident));
+        }
+        self.parse_path(mode)
+    }
+
     /// Examples:
     /// - `a::b<T,U>::c<V,W>`
     /// - `a::b<T,U>::c(V) -> W`
diff --git a/src/test/codegen/personality_lifetimes.rs b/src/test/codegen/personality_lifetimes.rs
new file mode 100644
index 0000000000000..e0de64b26df47
--- /dev/null
+++ b/src/test/codegen/personality_lifetimes.rs
@@ -0,0 +1,41 @@
+// Copyright 2017 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.
+
+// ignore-msvc
+
+// compile-flags: -O -C no-prepopulate-passes
+
+#![crate_type="lib"]
+
+struct S;
+
+impl Drop for S {
+    fn drop(&mut self) {
+    }
+}
+
+fn might_unwind() {
+}
+
+// CHECK-LABEL: @test
+#[no_mangle]
+pub fn test() {
+    let _s = S;
+    // Check that the personality slot alloca gets a lifetime start in each cleanup block, not just
+    // in the first one.
+    // CHECK-LABEL: cleanup:
+    // CHECK: bitcast{{.*}}personalityslot
+    // CHECK-NEXT: call void @llvm.lifetime.start
+    // CHECK-LABEL: cleanup1:
+    // CHECK: bitcast{{.*}}personalityslot
+    // CHECK-NEXT: call void @llvm.lifetime.start
+    might_unwind();
+    might_unwind();
+}
diff --git a/src/test/run-pass/issue-40962.rs b/src/test/run-pass/issue-40962.rs
new file mode 100644
index 0000000000000..b35cfa12eab18
--- /dev/null
+++ b/src/test/run-pass/issue-40962.rs
@@ -0,0 +1,20 @@
+// Copyright 2017 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.
+
+macro_rules! m {
+    ($i:meta) => {
+        #[derive($i)]
+        struct S;
+    }
+}
+
+m!(Clone);
+
+fn main() {}
diff --git a/src/tools/tidy/src/pal.rs b/src/tools/tidy/src/pal.rs
index 3808c05c6b939..0dbf0d4316abd 100644
--- a/src/tools/tidy/src/pal.rs
+++ b/src/tools/tidy/src/pal.rs
@@ -75,7 +75,7 @@ const EXCEPTION_PATHS: &'static [&'static str] = &[
     "src/libtest", // Probably should defer to unstable std::sys APIs
 
     // std testing crates, ok for now at least
-    "src/libcoretest",
+    "src/libcore/tests",
 
     // non-std crates
     "src/test",