Add riscv64imc target

These changes are based on 8dfd5c3 which added
the riscv32imc target.

Author: fintelia

src/ci/docker/dist-various-1/Dockerfile

@@ -112,6 +112,7 @@ ENV TARGETS=$TARGETS,thumbv7em-none-eabihf
 ENV TARGETS=$TARGETS,thumbv8m.main-none-eabi
 ENV TARGETS=$TARGETS,riscv32imc-unknown-none-elf
 ENV TARGETS=$TARGETS,riscv32imac-unknown-none-elf
+ENV TARGETS=$TARGETS,riscv64imc-unknown-none-elf
 ENV TARGETS=$TARGETS,armebv7r-none-eabi
 ENV TARGETS=$TARGETS,armebv7r-none-eabihf
 ENV TARGETS=$TARGETS,armv7r-none-eabi

src/librustc_target/spec/mod.rs

@@ -451,6 +451,7 @@ supported_targets! {
 
     ("riscv32imc-unknown-none-elf", riscv32imc_unknown_none_elf),
     ("riscv32imac-unknown-none-elf", riscv32imac_unknown_none_elf),
+    ("riscv64imc-unknown-none-elf", riscv64imc_unknown_none_elf),
 
     ("aarch64-unknown-none", aarch64_unknown_none),
 

src/librustc_target/spec/riscv64imc_unknown_none_elf.rs

@@ -0,0 +1,42 @@
+// Copyright 2018 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 spec::{LinkerFlavor, LldFlavor, PanicStrategy,
+           Target, TargetOptions, TargetResult};
+
+pub fn target() -> TargetResult {
+    Ok(Target {
+        data_layout: "e-m:e-i64:64-n64-S128".to_string(),
+        llvm_target: "riscv64".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "64".to_string(),
+        target_c_int_width: "32".to_string(),
+        target_os: "none".to_string(),
+        target_env: String::new(),
+        target_vendor: "unknown".to_string(),
+        arch: "riscv64".to_string(),
+        linker_flavor: LinkerFlavor::Lld(LldFlavor::Ld),
+
+        options: TargetOptions {
+            linker: Some("rust-lld".to_string()),
+            cpu: "generic-rv64".to_string(),
+            // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86005
+            max_atomic_width: None, //Some(32),
+            atomic_cas: false,
+            features: "+m,+c".to_string(),
+            executables: true,
+            panic_strategy: PanicStrategy::Abort,
+            relocation_model: "static".to_string(),
+            emit_debug_gdb_scripts: false,
+            abi_blacklist: super::riscv_base::abi_blacklist(),
+            .. Default::default()
+        },
+    })
+}

src/tools/build-manifest/src/main.rs

@@ -85,6 +85,7 @@ static TARGETS: &'static [&'static str] = &[
     "powerpc64le-unknown-linux-gnu",
     "riscv32imc-unknown-none-elf",
     "riscv32imac-unknown-none-elf",
+    "riscv64imc-unknown-none-elf",
     "s390x-unknown-linux-gnu",
     "sparc64-unknown-linux-gnu",
     "sparcv9-sun-solaris",