Auto merge of #36227 - jonathandturner:rollup, r=jonathandturner

Rollup of 12 pull requests

- Successful merges: #35754, #35793, #36099, #36160, #36171, #36178, #36180, #36190, #36198, #36205, #36210, #36223
- Failed merges:

Author: bors

.travis.yml

@@ -15,9 +15,9 @@ before_install:
 script:
   - docker run -v `pwd`:/build rust
     sh -c "
-      ./configure --llvm-root=/usr/lib/llvm-3.7 &&
+      ./configure --enable-rustbuild --llvm-root=/usr/lib/llvm-3.7 &&
       make tidy &&
-      make check-notidy -j4
+      make check -j4
     "
 
 # Real testing happens on http://buildbot.rust-lang.org/

configure

@@ -360,6 +360,13 @@ abs_path() {
     (unset CDPATH && cd "$_path" > /dev/null && pwd)
 }
 
+HELP=0
+for arg; do
+    case "$arg" in
+        --help) HELP=1;;
+    esac
+done
+
 msg "looking for configure programs"
 need_cmd cmp
 need_cmd mkdir
@@ -566,11 +573,8 @@ esac
 
 
 OPTIONS=""
-HELP=0
-if [ "$1" = "--help" ]
+if [ "$HELP" -eq 1 ]
 then
-    HELP=1
-    shift
     echo
     echo "Usage: $CFG_SELF [options]"
     echo

mk/main.mk

@@ -348,6 +348,7 @@ LLVM_AS_$(1)=$$(CFG_LLVM_INST_DIR_$(1))/bin/llvm-as$$(X_$(1))
 LLC_$(1)=$$(CFG_LLVM_INST_DIR_$(1))/bin/llc$$(X_$(1))
 
 LLVM_ALL_COMPONENTS_$(1)=$$(shell "$$(LLVM_CONFIG_$(1))" --components)
+LLVM_VERSION_$(1)=$$(shell "$$(LLVM_CONFIG_$(1))" --version)
 
 endef
 

mk/tests.mk

@@ -649,6 +649,7 @@ CTEST_COMMON_ARGS$(1)-T-$(2)-H-$(3) = \
 	--lldb-python $$(CFG_LLDB_PYTHON) \
         --gdb-version="$(CFG_GDB_VERSION)" \
         --lldb-version="$(CFG_LLDB_VERSION)" \
+        --llvm-version="$$(LLVM_VERSION_$(3))" \
         --android-cross-path=$(CFG_ARM_LINUX_ANDROIDEABI_NDK) \
         --adb-path=$(CFG_ADB) \
         --adb-test-dir=$(CFG_ADB_TEST_DIR) \

src/bootstrap/check.rs

@@ -148,6 +148,9 @@ pub fn compiletest(build: &Build,
     if let Some(ref dir) = build.lldb_python_dir {
         cmd.arg("--lldb-python-dir").arg(dir);
     }
+    let llvm_config = build.llvm_config(target);
+    let llvm_version = output(Command::new(&llvm_config).arg("--version"));
+    cmd.arg("--llvm-version").arg(llvm_version);
 
     cmd.args(&build.flags.args);
 
@@ -158,7 +161,6 @@ pub fn compiletest(build: &Build,
     // Only pass correct values for these flags for the `run-make` suite as it
     // requires that a C++ compiler was configured which isn't always the case.
     if suite == "run-make" {
-        let llvm_config = build.llvm_config(target);
         let llvm_components = output(Command::new(&llvm_config).arg("--components"));
         let llvm_cxxflags = output(Command::new(&llvm_config).arg("--cxxflags"));
         cmd.arg("--cc").arg(build.cc(target))

src/bootstrap/compile.rs

@@ -203,6 +203,10 @@ pub fn rustc<'a>(build: &'a Build, target: &str, compiler: &Compiler<'a>) {
         cargo.env("LLVM_RUSTLLVM", "1");
     }
     cargo.env("LLVM_CONFIG", build.llvm_config(target));
+    let target_config = build.config.target_config.get(target);
+    if let Some(s) = target_config.and_then(|c| c.llvm_config.as_ref()) {
+        cargo.env("CFG_LLVM_ROOT", s);
+    }
     if build.config.llvm_static_stdcpp {
         cargo.env("LLVM_STATIC_STDCPP",
                   compiler_file(build.cxx(target), "libstdc++.a"));

src/doc/reference.md

@@ -2071,6 +2071,9 @@ macro scope.
    trait of the same name. `{Self}` will be replaced with the type that is supposed
    to implement the trait but doesn't. To use this, the `on_unimplemented` feature gate
    must be enabled.
+- `must_use` - on structs and enums, will warn if a value of this type isn't used or
+   assigned to a variable. You may also include an optional message by using
+   `#[must_use = "message"]` which will be given alongside the warning.
 
 ### Conditional compilation
 

src/libcore/macros.rs

@@ -189,10 +189,19 @@ macro_rules! debug_assert_eq {
     ($($arg:tt)*) => (if cfg!(debug_assertions) { assert_eq!($($arg)*); })
 }
 
-/// Helper macro for unwrapping `Result` values while returning early with an
-/// error if the value of the expression is `Err`. Can only be used in
-/// functions that return `Result` because of the early return of `Err` that
-/// it provides.
+/// Helper macro for reducing boilerplate code for matching `Result` together
+/// with converting downstream errors.
+///
+/// `try!` matches the given `Result`. In case of the `Ok` variant, the
+/// expression has the value of the wrapped value.
+///
+/// In case of the `Err` variant, it retrieves the inner error. `try!` then
+/// performs conversion using `From`. This provides automatic conversion
+/// between specialized errors and more general ones. The resulting
+/// error is then immediately returned.
+///
+/// Because of the early return, `try!` can only be used in functions that
+/// return `Result`.
 ///
 /// # Examples
 ///
@@ -201,18 +210,28 @@ macro_rules! debug_assert_eq {
 /// use std::fs::File;
 /// use std::io::prelude::*;
 ///
-/// fn write_to_file_using_try() -> Result<(), io::Error> {
+/// enum MyError {
+///     FileWriteError
+/// }
+///
+/// impl From<io::Error> for MyError {
+///     fn from(e: io::Error) -> MyError {
+///         MyError::FileWriteError
+///     }
+/// }
+///
+/// fn write_to_file_using_try() -> Result<(), MyError> {
 ///     let mut file = try!(File::create("my_best_friends.txt"));
 ///     try!(file.write_all(b"This is a list of my best friends."));
 ///     println!("I wrote to the file");
 ///     Ok(())
 /// }
 /// // This is equivalent to:
-/// fn write_to_file_using_match() -> Result<(), io::Error> {
+/// fn write_to_file_using_match() -> Result<(), MyError> {
 ///     let mut file = try!(File::create("my_best_friends.txt"));
 ///     match file.write_all(b"This is a list of my best friends.") {
 ///         Ok(v) => v,
-///         Err(e) => return Err(e),
+///         Err(e) => return Err(From::from(e)),
 ///     }
 ///     println!("I wrote to the file");
 ///     Ok(())

src/libcore/ops.rs

@@ -282,6 +282,12 @@ macro_rules! forward_ref_binop {
 ///                Point { x: 3, y: 3 });
 /// }
 /// ```
+///
+/// Note that `RHS = Self` by default, but this is not mandatory. For example,
+/// [std::time::SystemTime] implements `Add<Duration>`, which permits
+/// operations of the form `SystemTime = SystemTime + Duration`.
+///
+/// [std::time::SystemTime]: ../../std/time/struct.SystemTime.html
 #[lang = "add"]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Add<RHS=Self> {
@@ -349,6 +355,12 @@ add_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 }
 ///                Point { x: 1, y: 0 });
 /// }
 /// ```
+///
+/// Note that `RHS = Self` by default, but this is not mandatory. For example,
+/// [std::time::SystemTime] implements `Sub<Duration>`, which permits
+/// operations of the form `SystemTime = SystemTime - Duration`.
+///
+/// [std::time::SystemTime]: ../../std/time/struct.SystemTime.html
 #[lang = "sub"]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Sub<RHS=Self> {

src/librustc_borrowck/borrowck/mod.rs

@@ -1028,6 +1028,12 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
             }
 
             err_out_of_scope(super_scope, sub_scope, cause) => {
+                let (value_kind, value_msg) = match err.cmt.cat {
+                    mc::Categorization::Rvalue(_) =>
+                        ("temporary value", "temporary value created here"),
+                    _ =>
+                        ("borrowed value", "does not live long enough")
+                };
                 match cause {
                     euv::ClosureCapture(s) => {
                         // The primary span starts out as the closure creation point.
@@ -1038,13 +1044,13 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
                             Some(primary) => {
                                 db.span = MultiSpan::from_span(s);
                                 db.span_label(primary, &format!("capture occurs here"));
-                                db.span_label(s, &format!("does not live long enough"));
+                                db.span_label(s, &value_msg);
                             }
                             None => ()
                         }
                     }
                     _ => {
-                        db.span_label(error_span, &format!("does not live long enough"));
+                        db.span_label(error_span, &value_msg);
                     }
                 }
 
@@ -1053,14 +1059,15 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
 
                 match (sub_span, super_span) {
                     (Some(s1), Some(s2)) if s1 == s2 => {
-                        db.span_label(s1, &"borrowed value dropped before borrower");
+                        db.span_label(s1, &format!("{} dropped before borrower", value_kind));
                         db.note("values in a scope are dropped in the opposite order \
                                 they are created");
                     }
                     _ => {
                         match sub_span {
                             Some(s) => {
-                                db.span_label(s, &"borrowed value must be valid until here");
+                                db.span_label(s, &format!("{} needs to live until here",
+                                                          value_kind));
                             }
                             None => {
                                 self.tcx.note_and_explain_region(
@@ -1072,7 +1079,7 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
                         }
                         match super_span {
                             Some(s) => {
-                                db.span_label(s, &"borrowed value only valid until here");
+                                db.span_label(s, &format!("{} only lives until here", value_kind));
                             }
                             None => {
                                 self.tcx.note_and_explain_region(
@@ -1085,9 +1092,8 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
                     }
                 }
 
-                if let Some(span) = statement_scope_span(self.tcx, super_scope) {
-                    db.span_help(span,
-                                 "consider using a `let` binding to increase its lifetime");
+                if let Some(_) = statement_scope_span(self.tcx, super_scope) {
+                    db.note("consider using a `let` binding to increase its lifetime");
                 }
             }