Merge branch 'master' into issue-30961

Author: bitshifter

configure

@@ -600,7 +600,7 @@ opt debug-assertions 0 "build with debugging assertions"
 opt fast-make 0 "use .gitmodules as timestamp for submodule deps"
 opt ccache 0 "invoke gcc/clang via ccache to reuse object files between builds"
 opt local-rust 0 "use an installed rustc rather than downloading a snapshot"
-opt local-rebuild 0 "use an installed rustc matching the current version, for rebuilds"
+opt local-rebuild 0 "assume local-rust matches the current version, for rebuilds; implies local-rust, and is implied if local-rust already matches the current version"
 opt llvm-static-stdcpp 0 "statically link to libstdc++ for LLVM"
 opt rpath 1 "build rpaths into rustc itself"
 opt stage0-landing-pads 1 "enable landing pads during bootstrap with stage0"
@@ -612,6 +612,7 @@ opt rustbuild 0 "use the rust and cargo based build system"
 opt orbit 0 "get MIR where it belongs - everywhere; most importantly, in orbit"
 opt codegen-tests 1 "run the src/test/codegen tests"
 opt option-checking 1 "complain about unrecognized options in this configure script"
+opt ninja 0 "build LLVM using the Ninja generator (for MSVC, requires building in the correct environment)"
 
 # Optimization and debugging options. These may be overridden by the release channel, etc.
 opt_nosave optimize 1 "build optimized rust code"
@@ -785,6 +786,17 @@ probe CFG_BISON            bison
 probe CFG_GDB              gdb
 probe CFG_LLDB             lldb
 
+if [ -n "$CFG_ENABLE_NINJA" ]
+then
+  probe CFG_NINJA            ninja
+  if [ -z "$CFG_NINJA" ]
+  then
+    # On Debian and Fedora, the `ninja` binary is an IRC bot, so the build tool was
+    # renamed. Handle this case.
+    probe CFG_NINJA            ninja-build
+  fi
+fi
+
 # For building LLVM
 probe_need CFG_CMAKE cmake
 
@@ -1534,7 +1546,10 @@ do
     fi
 
     # We need the generator later on for compiler-rt even if LLVM's not built
-    if [ ${is_msvc} -ne 0 ]
+    if [ -n "$CFG_NINJA" ]
+    then
+        generator="Ninja"
+    elif [ ${is_msvc} -ne 0 ]
     then
         case "$CFG_MSVC_ROOT" in
             *14.0*)

mk/cfg/mips-unknown-linux-gnu.mk

@@ -7,10 +7,10 @@ CFG_LIB_NAME_mips-unknown-linux-gnu=lib$(1).so
 CFG_STATIC_LIB_NAME_mips-unknown-linux-gnu=lib$(1).a
 CFG_LIB_GLOB_mips-unknown-linux-gnu=lib$(1)-*.so
 CFG_LIB_DSYM_GLOB_mips-unknown-linux-gnu=lib$(1)-*.dylib.dSYM
-CFG_JEMALLOC_CFLAGS_mips-unknown-linux-gnu := -mips32r2 -msoft-float -mabi=32 $(CFLAGS)
-CFG_GCCISH_CFLAGS_mips-unknown-linux-gnu := -Wall -g -fPIC -mips32r2 -msoft-float -mabi=32 $(CFLAGS)
+CFG_JEMALLOC_CFLAGS_mips-unknown-linux-gnu := -mips32r2 -mabi=32 $(CFLAGS)
+CFG_GCCISH_CFLAGS_mips-unknown-linux-gnu := -Wall -g -fPIC -mips32r2 -mabi=32 $(CFLAGS)
 CFG_GCCISH_CXXFLAGS_mips-unknown-linux-gnu := -fno-rtti $(CXXFLAGS)
-CFG_GCCISH_LINK_FLAGS_mips-unknown-linux-gnu := -shared -fPIC -g -mips32r2 -msoft-float -mabi=32
+CFG_GCCISH_LINK_FLAGS_mips-unknown-linux-gnu := -shared -fPIC -g -mips32r2 -mabi=32
 CFG_GCCISH_DEF_FLAG_mips-unknown-linux-gnu := -Wl,--export-dynamic,--dynamic-list=
 CFG_LLC_FLAGS_mips-unknown-linux-gnu :=
 CFG_INSTALL_NAME_mips-unknown-linux-gnu =

mk/llvm.mk

@@ -43,16 +43,26 @@ $$(LLVM_CONFIG_$(1)): $$(LLVM_DONE_$(1))
 
 $$(LLVM_DONE_$(1)): $$(LLVM_DEPS_TARGET_$(1)) $$(LLVM_STAMP_$(1))
 	@$$(call E, cmake: llvm)
-ifeq ($$(findstring msvc,$(1)),msvc)
+ifneq ($$(CFG_NINJA),)
+	$$(Q)$$(CFG_NINJA) -C $$(CFG_LLVM_BUILD_DIR_$(1))
+else ifeq ($$(findstring msvc,$(1)),msvc)
 	$$(Q)$$(CFG_CMAKE) --build $$(CFG_LLVM_BUILD_DIR_$(1)) \
 		--config $$(LLVM_BUILD_CONFIG_MODE)
 else
 	$$(Q)$$(MAKE) -C $$(CFG_LLVM_BUILD_DIR_$(1))
 endif
 	$$(Q)touch $$@
 
-ifeq ($$(findstring msvc,$(1)),msvc)
+ifneq ($$(CFG_NINJA),)
 clean-llvm$(1):
+	@$$(call E, clean: llvm)
+	$$(Q)$$(CFG_NINJA) -C $$(CFG_LLVM_BUILD_DIR_$(1)) -t clean
+else ifeq ($$(findstring msvc,$(1)),msvc)
+clean-llvm$(1):
+	@$$(call E, clean: llvm)
+	$$(Q)$$(CFG_CMAKE) --build $$(CFG_LLVM_BUILD_DIR_$(1)) \
+		--config $$(LLVM_BUILD_CONFIG_MODE) \
+		--target clean
 else
 clean-llvm$(1):
 	@$$(call E, clean: llvm)

mk/main.mk

@@ -20,29 +20,6 @@ CFG_RELEASE_NUM=1.12.0
 # versions (section 9)
 CFG_PRERELEASE_VERSION=.1
 
-# Append a version-dependent hash to each library, so we can install different
-# versions in the same place
-CFG_FILENAME_EXTRA=$(shell printf '%s' $(CFG_RELEASE)$(CFG_EXTRA_FILENAME) | $(CFG_HASH_COMMAND))
-
-# A magic value that allows the compiler to use unstable features during the
-# bootstrap even when doing so would normally be an error because of feature
-# staging or because the build turns on warnings-as-errors and unstable features
-# default to warnings. The build has to match this key in an env var.
-#
-# This value is keyed off the release to ensure that all compilers for one
-# particular release have the same bootstrap key. Note that this is
-# intentionally not "secure" by any definition, this is largely just a deterrent
-# from users enabling unstable features on the stable compiler.
-CFG_BOOTSTRAP_KEY=$(CFG_FILENAME_EXTRA)
-
-# The stage0 compiler needs to use the previous key recorded in src/stage0.txt,
-# except for local-rebuild when it just uses the same current key.
-ifdef CFG_ENABLE_LOCAL_REBUILD
-CFG_BOOTSTRAP_KEY_STAGE0=$(CFG_BOOTSTRAP_KEY)
-else
-CFG_BOOTSTRAP_KEY_STAGE0=$(shell grep 'rustc_key' $(S)src/stage0.txt | sed 's/rustc_key: '//)
-endif
-
 ifeq ($(CFG_RELEASE_CHANNEL),stable)
 # This is the normal semver version string, e.g. "0.12.0", "0.12.0-nightly"
 CFG_RELEASE=$(CFG_RELEASE_NUM)
@@ -72,6 +49,38 @@ CFG_RELEASE=$(CFG_RELEASE_NUM)-dev
 CFG_PACKAGE_VERS=$(CFG_RELEASE_NUM)-dev
 endif
 
+# Append a version-dependent hash to each library, so we can install different
+# versions in the same place
+CFG_FILENAME_EXTRA=$(shell printf '%s' $(CFG_RELEASE)$(CFG_EXTRA_FILENAME) | $(CFG_HASH_COMMAND))
+
+# A magic value that allows the compiler to use unstable features during the
+# bootstrap even when doing so would normally be an error because of feature
+# staging or because the build turns on warnings-as-errors and unstable features
+# default to warnings. The build has to match this key in an env var.
+#
+# This value is keyed off the release to ensure that all compilers for one
+# particular release have the same bootstrap key. Note that this is
+# intentionally not "secure" by any definition, this is largely just a deterrent
+# from users enabling unstable features on the stable compiler.
+CFG_BOOTSTRAP_KEY=$(CFG_FILENAME_EXTRA)
+
+# If local-rust is the same as the current version, then force a local-rebuild
+ifdef CFG_ENABLE_LOCAL_RUST
+ifeq ($(CFG_RELEASE),\
+      $(shell $(S)src/etc/local_stage0.sh --print-rustc-release $(CFG_LOCAL_RUST_ROOT)))
+    CFG_INFO := $(info cfg: auto-detected local-rebuild $(CFG_RELEASE))
+    CFG_ENABLE_LOCAL_REBUILD = 1
+endif
+endif
+
+# The stage0 compiler needs to use the previous key recorded in src/stage0.txt,
+# except for local-rebuild when it just uses the same current key.
+ifdef CFG_ENABLE_LOCAL_REBUILD
+CFG_BOOTSTRAP_KEY_STAGE0=$(CFG_BOOTSTRAP_KEY)
+else
+CFG_BOOTSTRAP_KEY_STAGE0=$(shell sed -ne 's/^rustc_key: //p' $(S)src/stage0.txt)
+endif
+
 # The name of the package to use for creating tarballs, installers etc.
 CFG_PACKAGE_NAME=rustc-$(CFG_PACKAGE_VERS)
 

mk/rt.mk

@@ -350,10 +350,17 @@ $$(COMPRT_LIB_$(1)): $$(COMPRT_DEPS) $$(MKFILE_DEPS) $$(LLVM_CONFIG_$$(CFG_BUILD
 		$$(COMPRT_DEFINES_$(1)) \
 		$$(COMPRT_BUILD_CC_$(1)) \
 		-G"$$(CFG_CMAKE_GENERATOR)"
+ifneq ($$(CFG_NINJA),)
+	$$(CFG_CMAKE) --build "$$(COMPRT_BUILD_DIR_$(1))" \
+		--target $$(COMPRT_BUILD_TARGET_$(1)) \
+		--config $$(LLVM_BUILD_CONFIG_MODE) \
+		-- $$(COMPRT_BUILD_ARGS_$(1))
+else
 	$$(Q)$$(CFG_CMAKE) --build "$$(COMPRT_BUILD_DIR_$(1))" \
 		--target $$(COMPRT_BUILD_TARGET_$(1)) \
 		--config $$(LLVM_BUILD_CONFIG_MODE) \
 		-- $$(COMPRT_BUILD_ARGS_$(1)) $$(MFLAGS)
+endif
 	$$(Q)cp "$$(COMPRT_OUTPUT_$(1))" $$@
 
 endif

mk/stage0.mk

@@ -11,6 +11,7 @@ endif
 
 $(SNAPSHOT_RUSTC_POST_CLEANUP): \
 		$(S)src/stage0.txt \
+		$(S)src/etc/local_stage0.sh \
 		$(S)src/etc/get-stage0.py $(MKFILE_DEPS) \
 		| $(HBIN0_H_$(CFG_BUILD))/
 	@$(call E, fetch: $@)

src/bootstrap/config.rs

@@ -317,6 +317,7 @@ impl Config {
                 ("OPTIMIZE_TESTS", self.rust_optimize_tests),
                 ("DEBUGINFO_TESTS", self.rust_debuginfo_tests),
                 ("LOCAL_REBUILD", self.local_rebuild),
+                ("NINJA", self.ninja),
             }
 
             match key {

src/bootstrap/lib.rs

@@ -118,6 +118,7 @@ pub struct Build {
     ver_date: Option<String>,
     version: String,
     package_vers: String,
+    local_rebuild: bool,
     bootstrap_key: String,
     bootstrap_key_stage0: String,
 
@@ -174,6 +175,7 @@ impl Build {
             Some(ref s) => PathBuf::from(s),
             None => stage0_root.join(exe("cargo", &config.build)),
         };
+        let local_rebuild = config.local_rebuild;
 
         Build {
             flags: flags,
@@ -189,6 +191,7 @@ impl Build {
             short_ver_hash: None,
             ver_date: None,
             version: String::new(),
+            local_rebuild: local_rebuild,
             bootstrap_key: String::new(),
             bootstrap_key_stage0: String::new(),
             package_vers: String::new(),
@@ -219,6 +222,16 @@ impl Build {
         sanity::check(self);
         self.verbose("collecting channel variables");
         channel::collect(self);
+        // If local-rust is the same as the current version, then force a local-rebuild
+        let local_version_verbose = output(
+            Command::new(&self.rustc).arg("--version").arg("--verbose"));
+        let local_release = local_version_verbose
+            .lines().filter(|x| x.starts_with("release:"))
+            .next().unwrap().trim_left_matches("release:").trim();
+        if local_release == self.release {
+            self.verbose(&format!("auto-detected local-rebuild {}", self.release));
+            self.local_rebuild = true;
+        }
         self.verbose("updating submodules");
         self.update_submodules();
 
@@ -525,7 +538,7 @@ impl Build {
              .arg("--target").arg(target);
 
         let stage;
-        if compiler.stage == 0 && self.config.local_rebuild {
+        if compiler.stage == 0 && self.local_rebuild {
             // Assume the local-rebuild rustc already has stage1 features.
             stage = 1;
         } else {
@@ -766,7 +779,7 @@ impl Build {
         // In stage0 we're using a previously released stable compiler, so we
         // use the stage0 bootstrap key. Otherwise we use our own build's
         // bootstrap key.
-        let bootstrap_key = if compiler.is_snapshot(self) && !self.config.local_rebuild {
+        let bootstrap_key = if compiler.is_snapshot(self) && !self.local_rebuild {
             &self.bootstrap_key_stage0
         } else {
             &self.bootstrap_key

src/doc/book/no-stdlib.md

@@ -21,7 +21,7 @@ this using our `Cargo.toml` file:
 
 ```toml
 [dependencies]
-libc = { version = "0.2.11", default-features = false }
+libc = { version = "0.2.14", default-features = false }
 ```
 
 Note that the default features have been disabled. This is a critical step -
@@ -36,8 +36,7 @@ or overriding the default shim for the C `main` function with your own.
 The function marked `#[start]` is passed the command line parameters
 in the same format as C:
 
-```rust
-# #![feature(libc)]
+```rust,ignore
 #![feature(lang_items)]
 #![feature(start)]
 #![no_std]
@@ -51,53 +50,77 @@ fn start(_argc: isize, _argv: *const *const u8) -> isize {
     0
 }
 
-// These functions and traits are used by the compiler, but not
+// These functions are used by the compiler, but not
 // for a bare-bones hello world. These are normally
 // provided by libstd.
-#[lang = "eh_personality"] extern fn eh_personality() {}
-#[lang = "panic_fmt"] extern fn panic_fmt() -> ! { loop {} }
-# #[lang = "eh_unwind_resume"] extern fn rust_eh_unwind_resume() {}
-# #[no_mangle] pub extern fn rust_eh_register_frames () {}
-# #[no_mangle] pub extern fn rust_eh_unregister_frames () {}
-# // fn main() {} tricked you, rustdoc!
+#[lang = "eh_personality"]
+#[no_mangle]
+pub extern fn eh_personality() {
+}
+
+#[lang = "panic_fmt"]
+#[no_mangle]
+pub extern fn rust_begin_panic(_msg: core::fmt::Arguments,
+                               _file: &'static str,
+                               _line: u32) -> ! {
+    loop {}
+}
 ```
 
 To override the compiler-inserted `main` shim, one has to disable it
 with `#![no_main]` and then create the appropriate symbol with the
 correct ABI and the correct name, which requires overriding the
 compiler's name mangling too:
 
-```rust
-# #![feature(libc)]
+```rust,ignore
 #![feature(lang_items)]
 #![feature(start)]
 #![no_std]
 #![no_main]
 
+// Pull in the system libc library for what crt0.o likely requires
 extern crate libc;
 
+// Entry point for this program
 #[no_mangle] // ensure that this symbol is called `main` in the output
-pub extern fn main(argc: i32, argv: *const *const u8) -> i32 {
+pub extern fn main(_argc: i32, _argv: *const *const u8) -> i32 {
     0
 }
 
-#[lang = "eh_personality"] extern fn eh_personality() {}
-#[lang = "panic_fmt"] extern fn panic_fmt() -> ! { loop {} }
-# #[lang = "eh_unwind_resume"] extern fn rust_eh_unwind_resume() {}
-# #[no_mangle] pub extern fn rust_eh_register_frames () {}
-# #[no_mangle] pub extern fn rust_eh_unregister_frames () {}
-# // fn main() {} tricked you, rustdoc!
+// These functions and traits are used by the compiler, but not
+// for a bare-bones hello world. These are normally
+// provided by libstd.
+#[lang = "eh_personality"]
+#[no_mangle]
+pub extern fn eh_personality() {
+}
+
+#[lang = "panic_fmt"]
+#[no_mangle]
+pub extern fn rust_begin_panic(_msg: core::fmt::Arguments,
+                               _file: &'static str,
+                               _line: u32) -> ! {
+    loop {}
+}
 ```
 
-The compiler currently makes a few assumptions about symbols which are available
-in the executable to call. Normally these functions are provided by the standard
-library, but without it you must define your own.
+## More about the langauge items
+
+The compiler currently makes a few assumptions about symbols which are
+available in the executable to call. Normally these functions are provided by
+the standard library, but without it you must define your own. These symbols
+are called "language items", and they each have an internal name, and then a
+signature that an implementation must conform to.
 
 The first of these two functions, `eh_personality`, is used by the failure
 mechanisms of the compiler. This is often mapped to GCC's personality function
 (see the [libstd implementation][unwind] for more information), but crates
 which do not trigger a panic can be assured that this function is never
-called. The second function, `panic_fmt`, is also used by the failure
-mechanisms of the compiler.
-
+called. Both the language item and the symbol name are `eh_personality`.
+ 
 [unwind]: https://github.com/rust-lang/rust/blob/master/src/libpanic_unwind/gcc.rs
+
+The second function, `panic_fmt`, is also used by the failure mechanisms of the
+compiler. When a panic happens, this controls the message that's displayed on
+the screen. While the language item's name is `panic_fmt`, the symbol name is
+`rust_begin_panic`.

src/doc/nomicon/phantom-data.md

@@ -51,12 +51,12 @@ struct Vec<T> {
 ```
 
 Unlike the previous example it *appears* that everything is exactly as we
-want. Every generic argument to Vec shows up in the at least one field.
+want. Every generic argument to Vec shows up in at least one field.
 Good to go!
 
 Nope.
 
-The drop checker will generously determine that Vec<T> does not own any values
+The drop checker will generously determine that `Vec<T>` does not own any values
 of type T. This will in turn make it conclude that it doesn't need to worry
 about Vec dropping any T's in its destructor for determining drop check
 soundness. This will in turn allow people to create unsoundness using
@@ -81,7 +81,7 @@ Raw pointers that own an allocation is such a pervasive pattern that the
 standard library made a utility for itself called `Unique<T>` which:
 
 * wraps a `*const T` for variance
-* includes a `PhantomData<T>`,
+* includes a `PhantomData<T>`
 * auto-derives Send/Sync as if T was contained
 * marks the pointer as NonZero for the null-pointer optimization