Auto merge of #28593 - gandro:rumprun, r=alexcrichton

This adds a new target, `x86_64-rumprun-netbsd`, and related changes to `std`.

Rumprun is a unikernel platform that provides a POSIX-y interface. For the most part, rumprun uses NetBSD's libc and drivers, therefore `target_os` is `netbsd`. However, being a unikernel, rumprun does not support process management, signals or virtual memory, so related functions might fail at runtime. For this reason, stack guards are disabled in `std`.

To support conditional compilation, `target_env` is set to `rumprun`. Maybe `target_vendor` would be technically more fitting, but it doesn't seem to be worth the hassle.

Code for rumprun is always cross-compiled, it uses always static linking and needs a custom linker. The target makes use of the newly introduced `no_default_libs` flag, as the rumprun linker will otherwise not use the correct search path.

Author: bors

configure

@@ -1295,6 +1295,12 @@ $ pacman -R cmake && pacman -S mingw-w64-x86_64-cmake
             putvar CFG_MSVC_LIB_PATH_${bits}
             ;;
 
+        *-rumprun-netbsd)
+            step_msg "targeting rumprun-netbsd, disabling jemalloc"
+            CFG_DISABLE_JEMALLOC=1
+            putvar CFG_DISABLE_JEMALLOC
+            ;;
+
         *)
             ;;
     esac

mk/cfg/x86_64-rumprun-netbsd.mk

@@ -0,0 +1,24 @@
+# x86_64-rumprun-netbsd configuration
+CROSS_PREFIX_x86_64-rumprun-netbsd=x86_64-rumprun-netbsd-
+CC_x86_64-rumprun-netbsd=gcc
+CXX_x86_64-rumprun-netbsd=g++
+CPP_x86_64-rumprun-netbsd=gcc -E
+AR_x86_64-rumprun-netbsd=ar
+CFG_INSTALL_ONLY_RLIB_x86_64-rumprun-netbsd = 1
+CFG_LIB_NAME_x86_64-rumprun-netbsd=lib$(1).so
+CFG_STATIC_LIB_NAME_x86_64-rumprun-netbsd=lib$(1).a
+CFG_LIB_GLOB_x86_64-rumprun-netbsd=lib$(1)-*.so
+CFG_JEMALLOC_CFLAGS_x86_64-rumprun-netbsd := -m64
+CFG_GCCISH_CFLAGS_x86_64-rumprun-netbsd := -Wall -Werror -g -fPIC -m64
+CFG_GCCISH_CXXFLAGS_x86_64-rumprun-netbsd :=
+CFG_GCCISH_LINK_FLAGS_x86_64-rumprun-netbsd :=
+CFG_GCCISH_DEF_FLAG_x86_64-rumprun-netbsd :=
+CFG_LLC_FLAGS_x86_64-rumprun-netbsd :=
+CFG_INSTALL_NAME_x86_64-rumprun-netbsd =
+CFG_EXE_SUFFIX_x86_64-rumprun-netbsd =
+CFG_WINDOWSY_x86_64-rumprun-netbsd :=
+CFG_UNIXY_x86_64-rumprun-netbsd := 1
+CFG_LDPATH_x86_64-rumprun-netbsd :=
+CFG_RUN_x86_64-rumprun-netbsd=$(2)
+CFG_RUN_TARG_x86_64-rumprun-netbsd=$(call CFG_RUN_x86_64-rumprun-netbsd,,$(2))
+CFG_GNU_TRIPLE_x86_64-rumprun-netbsd := x86_64-rumprun-netbsd

src/liblibc/lib.rs

@@ -24,6 +24,7 @@
        html_playground_url = "https://play.rust-lang.org/",
        issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/")]
 #![cfg_attr(test, feature(test))]
+#![feature(cfg_target_vendor)]
 
 //! Bindings for the C standard library and other platform libraries
 //!
@@ -143,7 +144,10 @@ pub use funcs::bsd43::*;
 
 // On NaCl, these libraries are static. Thus it would be a Bad Idea to link them
 // in when creating a test crate.
-#[cfg(not(any(windows, target_env = "musl", all(target_os = "nacl", test))))]
+#[cfg(not(any(windows,
+              target_env = "musl",
+              all(target_os = "nacl", test),
+              all(target_os = "netbsd", target_vendor = "rumprun"))))]
 #[link(name = "c")]
 #[link(name = "m")]
 extern {}

src/librustc_back/target/mod.rs

@@ -411,6 +411,7 @@ impl Target {
             x86_64_unknown_bitrig,
             x86_64_unknown_openbsd,
             x86_64_unknown_netbsd,
+            x86_64_rumprun_netbsd,
 
             x86_64_apple_darwin,
             i686_apple_darwin,

src/librustc_back/target/x86_64_rumprun_netbsd.rs

@@ -0,0 +1,35 @@
+// Copyright 2014-2015 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.
+
+use target::Target;
+
+pub fn target() -> Target {
+    let mut base = super::netbsd_base::opts();
+    base.pre_link_args.push("-m64".to_string());
+    base.linker = "x86_64-rumprun-netbsd-gcc".to_string();
+    base.ar = "x86_64-rumprun-netbsd-ar".to_string();
+
+    base.dynamic_linking = false;
+    base.has_rpath = false;
+    base.position_independent_executables = false;
+    base.disable_redzone = true;
+    base.no_default_libraries = false;
+
+    Target {
+        llvm_target: "x86_64-rumprun-netbsd".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "64".to_string(),
+        arch: "x86_64".to_string(),
+        target_os: "netbsd".to_string(),
+        target_env: "".to_string(),
+        target_vendor: "rumprun".to_string(),
+        options: base,
+    }
+}

src/libstd/lib.rs

@@ -204,6 +204,7 @@
 #![feature(associated_consts)]
 #![feature(borrow_state)]
 #![feature(box_syntax)]
+#![feature(cfg_target_vendor)]
 #![feature(char_from_unchecked)]
 #![feature(char_internals)]
 #![feature(clone_from_slice)]

src/libstd/sys/common/libunwind.rs

@@ -108,10 +108,18 @@ extern {}
 #[link(name = "unwind", kind = "static")]
 extern {}
 
-#[cfg(any(target_os = "android", target_os = "netbsd", target_os = "openbsd"))]
+#[cfg(any(target_os = "android", target_os = "openbsd"))]
 #[link(name = "gcc")]
 extern {}
 
+#[cfg(all(target_os = "netbsd", not(target_vendor = "rumprun")))]
+#[link(name = "gcc")]
+extern {}
+
+#[cfg(all(target_os = "netbsd", target_vendor = "rumprun"))]
+#[link(name = "unwind")]
+extern {}
+
 #[cfg(target_os = "dragonfly")]
 #[link(name = "gcc_pic")]
 extern {}

src/libstd/sys/unix/stack_overflow.rs

@@ -34,7 +34,7 @@ impl Drop for Handler {
 #[cfg(any(target_os = "linux",
           target_os = "macos",
           target_os = "bitrig",
-          target_os = "netbsd",
+          all(target_os = "netbsd", not(target_vendor = "rumprun")),
           target_os = "openbsd"))]
 mod imp {
     use super::Handler;
@@ -143,7 +143,7 @@ mod imp {
 #[cfg(not(any(target_os = "linux",
               target_os = "macos",
               target_os = "bitrig",
-              target_os = "netbsd",
+              all(target_os = "netbsd", not(target_vendor = "rumprun")),
               target_os = "openbsd")))]
 mod imp {
     use ptr;

src/libstd/sys/unix/thread.rs

@@ -174,7 +174,7 @@ impl Drop for Thread {
 #[cfg(all(not(target_os = "linux"),
           not(target_os = "macos"),
           not(target_os = "bitrig"),
-          not(target_os = "netbsd"),
+          not(all(target_os = "netbsd", not(target_vendor = "rumprun"))),
           not(target_os = "openbsd")))]
 pub mod guard {
     pub unsafe fn current() -> Option<usize> { None }
@@ -185,7 +185,7 @@ pub mod guard {
 #[cfg(any(target_os = "linux",
           target_os = "macos",
           target_os = "bitrig",
-          target_os = "netbsd",
+          all(target_os = "netbsd", not(target_vendor = "rumprun")),
           target_os = "openbsd"))]
 #[allow(unused_imports)]
 pub mod guard {