Add new Tier-3 target: loongarch64-unknown-linux-ohos

MCP: https://github.com/rust-lang/compiler-team/issues/784

Co-authored-by: WANG Rui <wangrui@loongson.cn>

compiler/rustc_target/src/spec/mod.rs

@@ -1886,6 +1886,7 @@ supported_targets! {
 
     ("aarch64-unknown-linux-ohos", aarch64_unknown_linux_ohos),
     ("armv7-unknown-linux-ohos", armv7_unknown_linux_ohos),
+    ("loongarch64-unknown-linux-ohos", loongarch64_unknown_linux_ohos),
     ("x86_64-unknown-linux-ohos", x86_64_unknown_linux_ohos),
 
     ("x86_64-unknown-linux-none", x86_64_unknown_linux_none),

compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_ohos.rs

@@ -0,0 +1,24 @@
+use crate::spec::{Target, TargetOptions, base};
+
+pub(crate) fn target() -> Target {
+    Target {
+        // LLVM 15 doesn't support OpenHarmony yet, use a linux target instead.
+        llvm_target: "loongarch64-unknown-linux-musl".into(),
+        metadata: crate::spec::TargetMetadata {
+            description: Some("LoongArch64 OpenHarmony".into()),
+            tier: Some(3),
+            host_tools: Some(false),
+            std: Some(true),
+        },
+        pointer_width: 64,
+        data_layout: "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128".into(),
+        arch: "loongarch64".into(),
+        options: TargetOptions {
+            cpu: "generic".into(),
+            features: "+f,+d".into(),
+            llvm_abiname: "lp64d".into(),
+            max_atomic_width: Some(64),
+            ..base::linux_ohos::opts()
+        },
+    }
+}

src/doc/rustc/src/platform-support.md

@@ -315,6 +315,7 @@ target | std | host | notes
 `i686-uwp-windows-msvc` | ✓ |  | [^x86_32-floats-return-ABI]
 [`i686-win7-windows-msvc`](platform-support/win7-windows-msvc.md) | ✓ |   | 32-bit Windows 7 support [^x86_32-floats-return-ABI]
 [`i686-wrs-vxworks`](platform-support/vxworks.md) | ✓ |  | [^x86_32-floats-return-ABI]
+[`loongarch64-unknown-linux-ohos`](platform-support/openharmony.md) | ✓ |   | LoongArch64 OpenHarmony
 [`m68k-unknown-linux-gnu`](platform-support/m68k-unknown-linux-gnu.md) | ? |  | Motorola 680x0 Linux
 `mips-unknown-linux-gnu` | ✓ | ✓ | MIPS Linux (kernel 4.4, glibc 2.23)
 `mips-unknown-linux-musl` | ✓ |  | MIPS Linux with musl 1.2.3

src/doc/rustc/src/platform-support/openharmony.md

@@ -2,6 +2,14 @@
 
 **Tier: 2**
 
+* aarch64-unknown-linux-ohos
+* armv7-unknown-linux-ohos
+* x86_64-unknown-linux-ohos
+
+**Tier: 3**
+
+* loongarch64-unknown-linux-ohos
+
 Targets for the [OpenHarmony](https://gitee.com/openharmony/docs/) operating
 system.
 

tests/assembly/targets/targets-elf.rs

@@ -252,6 +252,9 @@
 //@ revisions: loongarch64_unknown_linux_musl
 //@ [loongarch64_unknown_linux_musl] compile-flags: --target loongarch64-unknown-linux-musl
 //@ [loongarch64_unknown_linux_musl] needs-llvm-components: loongarch
+//@ revisions: loongarch64_unknown_linux_ohos
+//@ [loongarch64_unknown_linux_ohos] compile-flags: --target loongarch64-unknown-linux-ohos
+//@ [loongarch64_unknown_linux_ohos] needs-llvm-components: loongarch
 //@ revisions: loongarch64_unknown_none
 //@ [loongarch64_unknown_none] compile-flags: --target loongarch64-unknown-none
 //@ [loongarch64_unknown_none] needs-llvm-components: loongarch