Add OpenHarmony targets

- `aarch64-unknown-linux-ohos`
- `armv7-unknown-linux-ohos`

compiler/rustc_target/src/spec/aarch64_unknown_linux_ohos.rs

@@ -0,0 +1,31 @@
+use crate::spec::{Target, TargetOptions};
+
+use super::SanitizerSet;
+
+pub fn target() -> Target {
+    let mut base = super::linux_musl_base::opts();
+    base.env = "ohos".into();
+    base.crt_static_default = false;
+    base.max_atomic_width = Some(128);
+
+    Target {
+        // LLVM 15 doesn't support OpenHarmony yet, use a linux target instead.
+        llvm_target: "aarch64-unknown-linux-musl".into(),
+        pointer_width: 64,
+        data_layout: "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128".into(),
+        arch: "aarch64".into(),
+        options: TargetOptions {
+            features: "+reserve-x18".into(),
+            mcount: "\u{1}_mcount".into(),
+            force_emulated_tls: true,
+            supported_sanitizers: SanitizerSet::ADDRESS
+                | SanitizerSet::CFI
+                | SanitizerSet::LEAK
+                | SanitizerSet::MEMORY
+                | SanitizerSet::MEMTAG
+                | SanitizerSet::THREAD
+                | SanitizerSet::HWADDRESS,
+            ..base
+        },
+    }
+}

compiler/rustc_target/src/spec/armv7_unknown_linux_ohos.rs

@@ -0,0 +1,27 @@
+use crate::spec::{Target, TargetOptions};
+
+// This target is for OpenHarmony on ARMv7 Linux with thumb-mode, but no NEON or
+// hardfloat.
+
+pub fn target() -> Target {
+    // Most of these settings are copied from the armv7_unknown_linux_musleabi
+    // target.
+    Target {
+        // LLVM 15 doesn't support OpenHarmony yet, use a linux target instead.
+        llvm_target: "armv7-unknown-linux-gnueabi".into(),
+        pointer_width: 32,
+        data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
+        arch: "arm".into(),
+
+        options: TargetOptions {
+            abi: "eabi".into(),
+            features: "+v7,+thumb2,+soft-float,-neon".into(),
+            max_atomic_width: Some(64),
+            env: "ohos".into(),
+            crt_static_default: false,
+            mcount: "\u{1}mcount".into(),
+            force_emulated_tls: true,
+            ..super::linux_musl_base::opts()
+        },
+    }
+}

compiler/rustc_target/src/spec/mod.rs

@@ -1261,6 +1261,9 @@ supported_targets! {
 
     ("aarch64-unknown-nto-qnx710", aarch64_unknown_nto_qnx_710),
     ("x86_64-pc-nto-qnx710", x86_64_pc_nto_qnx710),
+
+    ("aarch64-unknown-linux-ohos", aarch64_unknown_linux_ohos),
+    ("armv7-unknown-linux-ohos", armv7_unknown_linux_ohos),
 }
 
 /// Cow-Vec-Str: Cow<'static, [Cow<'static, str>]>
@@ -1734,6 +1737,9 @@ pub struct TargetOptions {
 
     /// Whether the target supports XRay instrumentation.
     pub supports_xray: bool,
+
+    /// Forces the use of emulated TLS (__emutls_get_address)
+    pub force_emulated_tls: bool,
 }
 
 /// Add arguments for the given flavor and also for its "twin" flavors
@@ -1954,6 +1960,7 @@ impl Default for TargetOptions {
             entry_name: "main".into(),
             entry_abi: Conv::C,
             supports_xray: false,
+            force_emulated_tls: false,
         }
     }
 }
@@ -2605,6 +2612,7 @@ impl Target {
         key!(entry_name);
         key!(entry_abi, Conv)?;
         key!(supports_xray, bool);
+        key!(force_emulated_tls, bool);
 
         if base.is_builtin {
             // This can cause unfortunate ICEs later down the line.
@@ -2859,6 +2867,7 @@ impl ToJson for Target {
         target_option_val!(entry_name);
         target_option_val!(entry_abi);
         target_option_val!(supports_xray);
+        target_option_val!(force_emulated_tls);
 
         if let Some(abi) = self.default_adjusted_cabi {
             d.insert("default-adjusted-cabi".into(), Abi::name(abi).to_json());