Add no_std AArch64 support for the QNX Neutrino (nto) 7.1 RTOS

This change allows to compile no_std applications for the QNX Neutrino
realtime operating system for ARM 64 bit CPUs.
Tested with QNX Neutrino 7.1.

4 files changed, 72 insertions, 0 deletions

diff --git a/compiler/rustc_target/src/spec/aarch64_unknown_nto_qnx_710.rs b/compiler/rustc_target/src/spec/aarch64_unknown_nto_qnx_710.rs
new file mode 100644
index 00000000000..916b6137b65
--- /dev/null
+++ b/compiler/rustc_target/src/spec/aarch64_unknown_nto_qnx_710.rs
@@ -0,0 +1,28 @@
+use super::nto_qnx_base;
+use crate::spec::{Cc, LinkerFlavor, Lld, Target, TargetOptions};
+
+pub fn target() -> Target {
+    Target {
+        llvm_target: "aarch64-unknown-unknown".into(),
+        pointer_width: 64,
+        // from: https://llvm.org/docs/LangRef.html#data-layout
+        // e         = little endian
+        // m:e       = ELF mangling: Private symbols get a .L prefix
+        // i8:8:32   = 8-bit-integer, minimum_alignment=8, preferred_alignment=32
+        // i16:16:32 = 16-bit-integer, minimum_alignment=16, preferred_alignment=32
+        // i64:64    = 64-bit-integer, minimum_alignment=64, preferred_alignment=64
+        // i128:128  = 128-bit-integer, minimum_alignment=128, preferred_alignment=128
+        // n32:64    = 32 and 64 are native integer widths; Elements of this set are considered to support most general arithmetic operations efficiently.
+        // S128      = 128 bits are the natural alignment of the stack in bits.
+        data_layout: "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128".into(),
+        arch: "aarch64".into(),
+        options: TargetOptions {
+            max_atomic_width: Some(128),
+            pre_link_args: TargetOptions::link_args(
+                LinkerFlavor::Gnu(Cc::Yes, Lld::No),
+                &["-Vgcc_ntoaarch64le_cxx"],
+            ),
+            ..nto_qnx_base::opts()
+        },
+    }
+}
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index 77d9a092003..e809f646860 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -74,6 +74,7 @@ mod linux_musl_base;
 mod linux_uclibc_base;
 mod msvc_base;
 mod netbsd_base;
+mod nto_qnx_base;
 mod openbsd_base;
 mod redox_base;
 mod solaris_base;
@@ -1242,6 +1243,9 @@ supported_targets! {
     ("x86_64-unknown-none", x86_64_unknown_none),
 
     ("mips64-openwrt-linux-musl", mips64_openwrt_linux_musl),
+
+    ("aarch64-unknown-nto-qnx7.1.0", aarch64_unknown_nto_qnx_710),
+    ("x86_64-pc-nto-qnx7.1.0", x86_64_pc_nto_qnx710),
 }
 
 /// Cow-Vec-Str: Cow<'static, [Cow<'static, str>]>
diff --git a/compiler/rustc_target/src/spec/nto_qnx_base.rs b/compiler/rustc_target/src/spec/nto_qnx_base.rs
new file mode 100644
index 00000000000..6fb581ef5ce
--- /dev/null
+++ b/compiler/rustc_target/src/spec/nto_qnx_base.rs
@@ -0,0 +1,19 @@
+use crate::spec::{cvs, RelroLevel, TargetOptions};
+
+pub fn opts() -> TargetOptions {
+    TargetOptions {
+        crt_static_respected: true,
+        dynamic_linking: true,
+        env: "nto71".into(),
+        executables: true,
+        families: cvs!["unix"],
+        has_rpath: true,
+        has_thread_local: false,
+        linker: Some("qcc".into()),
+        os: "nto".into(),
+        position_independent_executables: true,
+        static_position_independent_executables: true,
+        relro_level: RelroLevel::Full,
+        ..Default::default()
+    }
+}
diff --git a/compiler/rustc_target/src/spec/x86_64_pc_nto_qnx710.rs b/compiler/rustc_target/src/spec/x86_64_pc_nto_qnx710.rs
new file mode 100644
index 00000000000..e9b3acee2e7
--- /dev/null
+++ b/compiler/rustc_target/src/spec/x86_64_pc_nto_qnx710.rs
@@ -0,0 +1,21 @@
+use super::nto_qnx_base;
+use crate::spec::{Cc, LinkerFlavor, Lld, Target, TargetOptions};
+
+pub fn target() -> Target {
+    Target {
+        llvm_target: "x86_64-pc-unknown".into(),
+        pointer_width: 64,
+        data_layout: "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+            .into(),
+        arch: "x86_64".into(),
+        options: TargetOptions {
+            cpu: "x86-64".into(),
+            max_atomic_width: Some(64),
+            pre_link_args: TargetOptions::link_args(
+                LinkerFlavor::Gnu(Cc::Yes, Lld::No),
+                &["-Vgcc_ntox86_64_cxx"],
+            ),
+            ..nto_qnx_base::opts()
+        },
+    }
+}