add a built-in MSP430 target

Author: japaric

src/librustc_back/target/mod.rs

@@ -220,6 +220,8 @@ supported_targets! {
     ("thumbv7m-none-eabi", thumbv7m_none_eabi),
     ("thumbv7em-none-eabi", thumbv7em_none_eabi),
     ("thumbv7em-none-eabihf", thumbv7em_none_eabihf),
+
+    ("msp430-none-elf", msp430_none_elf),
 }
 
 /// Everything `rustc` knows about how to compile for a specific target.

src/librustc_back/target/msp430_none_elf.rs

@@ -0,0 +1,53 @@
+// 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.
+
+use {LinkerFlavor, PanicStrategy};
+use target::{Target, TargetOptions, TargetResult};
+
+pub fn target() -> TargetResult {
+    Ok(Target {
+        llvm_target: "msp430-none-elf".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "16".to_string(),
+        data_layout: "e-m:e-p:16:16-i32:16-i64:16-f32:16-f64:16-a:8-n8:16-S16".to_string(),
+        arch: "msp430".to_string(),
+        target_os: "none".to_string(),
+        target_env: "".to_string(),
+        target_vendor: "".to_string(),
+        linker_flavor: LinkerFlavor::Gcc,
+
+        options: TargetOptions {
+            executables: true,
+
+            // The LLVM backend currently can't generate object files. To
+            // workaround this LLVM generates assembly files which then we feed
+            // to gcc to get object files. For this reason we have a hard
+            // dependency on this specific gcc.
+            asm_args: vec!["-mcpu=msp430".to_string()],
+            linker: "msp430-elf-gcc".to_string(),
+            no_integrated_as: true,
+
+            // There are no atomic instructions available in the MSP430
+            // instruction set
+            max_atomic_width: Some(0),
+
+            // Because these devices have very little resources having an
+            // unwinder is too onerous so we default to "abort" because the
+            // "unwind" strategy is very rare.
+            panic_strategy: PanicStrategy::Abort,
+
+            // Similarly, one almost always never wants to use relocatable
+            // code because of the extra costs it involves.
+            relocation_model: "static".to_string(),
+
+            .. Default::default( )
+        }
+    })
+}