Add Trusty OS as tier 3 target

compiler/rustc_target/src/spec/aarch64_unknown_trusty.rs

@@ -0,0 +1,30 @@
+// Trusty OS target for AArch64.
+
+use super::{
+    crt_objects::LinkSelfContainedDefault, PanicStrategy, RelroLevel, Target, TargetOptions,
+};
+
+pub fn target() -> Target {
+    Target {
+        llvm_target: "aarch64-unknown-unknown-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: "+neon,+fp-armv8,+reserve-x18".into(),
+            executables: true,
+            max_atomic_width: Some(128),
+            panic_strategy: PanicStrategy::Abort,
+            os: "trusty".into(),
+            position_independent_executables: true,
+            static_position_independent_executables: true,
+            crt_static_default: true,
+            crt_static_respected: false,
+            dynamic_linking: false,
+            link_self_contained: LinkSelfContainedDefault::Musl,
+            relro_level: RelroLevel::Full,
+            mcount: "\u{1}_mcount".into(),
+            ..Default::default()
+        },
+    }
+}

compiler/rustc_target/src/spec/armv7_unknown_trusty.rs

@@ -0,0 +1,33 @@
+use crate::spec::{Target, TargetOptions};
+
+use super::{crt_objects::LinkSelfContainedDefault, PanicStrategy, RelroLevel};
+
+pub fn target() -> Target {
+    Target {
+        // It's important we use "gnueabi" and not "musleabi" here. LLVM uses it
+        // to determine the calling convention and float ABI, and it doesn't
+        // support the "musleabi" value.
+        llvm_target: "armv7-unknown-unknown-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,+reserve-x18".into(),
+            max_atomic_width: Some(64),
+            mcount: "\u{1}mcount".into(),
+            os: "trusty".into(),
+            link_self_contained: LinkSelfContainedDefault::Musl,
+            dynamic_linking: false,
+            executables: true,
+            crt_static_default: true,
+            crt_static_respected: false,
+            relro_level: RelroLevel::Full,
+            panic_strategy: PanicStrategy::Abort,
+            position_independent_executables: true,
+            static_position_independent_executables: true,
+
+            ..Default::default()
+        },
+    }
+}

compiler/rustc_target/src/spec/mod.rs

@@ -1190,6 +1190,9 @@ supported_targets! {
     ("aarch64-unknown-hermit", aarch64_unknown_hermit),
     ("x86_64-unknown-hermit", x86_64_unknown_hermit),
 
+    ("armv7-unknown-trusty", armv7_unknown_trusty),
+    ("aarch64-unknown-trusty", aarch64_unknown_trusty),
+
     ("riscv32i-unknown-none-elf", riscv32i_unknown_none_elf),
     ("riscv32im-unknown-none-elf", riscv32im_unknown_none_elf),
     ("riscv32imc-unknown-none-elf", riscv32imc_unknown_none_elf),

compiler/rustc_target/src/spec/tests/tests_impl.rs

@@ -143,8 +143,9 @@ impl Target {
             assert!(self.executables);
         }
 
-        // Check crt static stuff
-        if self.crt_static_default || self.crt_static_allows_dylibs {
+        // Check crt static stuff. Trusy only supports crt static and so does not enable
+        // `crt_static_respected`.
+        if (self.crt_static_default || self.crt_static_allows_dylibs) && self.os != "trusty" {
             assert!(self.crt_static_respected);
         }
     }

src/doc/rustc/src/SUMMARY.md

@@ -27,6 +27,7 @@
     - [armv7-unknown-linux-uclibceabihf](platform-support/armv7-unknown-linux-uclibceabihf.md)
     - [\*-android and \*-androideabi](platform-support/android.md)
     - [\*-unknown-fuchsia](platform-support/fuchsia.md)
+    - [\*-unknown-trusty](platform-support/trusty.md)
     - [\*-kmc-solid_\*](platform-support/kmc-solid.md)
     - [m68k-unknown-linux-gnu](platform-support/m68k-unknown-linux-gnu.md)
     - [mips64-openwrt-linux-musl](platform-support/mips64-openwrt-linux-musl.md)

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

@@ -223,6 +223,7 @@ target | std | host | notes
 `aarch64-unknown-netbsd` | ✓ | ✓ |
 [`aarch64-unknown-openbsd`](platform-support/openbsd.md) | ✓ | ✓ | ARM64 OpenBSD
 `aarch64-unknown-redox` | ? |  | ARM64 Redox OS
+[`aarch64-unknown-trusty`](platform-support/trusty.md) | ? |  |
 `aarch64-uwp-windows-msvc` | ? |  |
 `aarch64-wrs-vxworks` | ? |  |
 `aarch64_be-unknown-linux-gnu_ilp32` | ✓ | ✓ | ARM64 Linux (big-endian, ILP32 ABI)
@@ -242,6 +243,7 @@ target | std | host | notes
 [`armv7-unknown-linux-uclibceabihf`](platform-support/armv7-unknown-linux-uclibceabihf.md) | ✓ | ? | ARMv7 Linux with uClibc, hardfloat
 `armv7-unknown-freebsd` | ✓ | ✓ | ARMv7 FreeBSD
 `armv7-unknown-netbsd-eabihf` | ✓ | ✓ |
+[`armv7-unknown-trusty`](platform-support/trusty.md) | ? |  |
 `armv7-wrs-vxworks-eabihf` | ? |  |
 [`armv7a-kmc-solid_asp3-eabi`](platform-support/kmc-solid.md) | ✓ |  | ARM SOLID with TOPPERS/ASP3
 [`armv7a-kmc-solid_asp3-eabihf`](platform-support/kmc-solid.md) | ✓ |  | ARM SOLID with TOPPERS/ASP3, hardfloat

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

@@ -0,0 +1,53 @@
+# `aarch64-unknown-trusty` and `armv7-unknown-trusty`
+
+**Tier: 3**
+
+[Trusty] is a secure Operating System that provides a Trusted Execution
+Environment (TEE) for Android.
+
+## Target maintainers
+
+- Nicole LeGare (@randomPoison)
+- Stephen Crane (@rinon)
+- As a fallback [email protected] can be contacted
+
+## Requirements
+
+This target is cross-compiled. It has no special requirements for the host.
+
+It fully supports alloc with the default allocator, and partially supports std.
+Notably, most I/O functionality is not supported, e.g. filesystem support and
+networking support are not present and any APIs that rely on them will panic at
+runtime.
+
+Trusty uses the ELF file format.
+
+## Building the target
+
+The targets can be built by enabling them for a `rustc` build, for example:
+
+```toml
+[build]
+build-stage = 1
+target = ["aarch64-unknown-trusty", "armv7-unknown-trusty"]
+```
+
+## Building Rust programs
+
+There is currently no supported way to build a Trusty app with Cargo. You can
+follow the [Trusty build instructions] to build the Trusty kernel along with any
+Rust apps that are setup in the project.
+
+## Testing
+
+See the [Trusty build instructions] for information on how to build Rust code
+within the main Trusty project. The main project also includes infrastructure
+for testing Rust applications within a QEMU emulator.
+
+## Cross-compilation toolchains and C code
+
+See the [Trusty build instructions] for information on how C code is built
+within Trusty.
+
+[Trusty]: https://source.android.com/docs/security/features/trusty
+[Trusty build instructions]: https://source.android.com/docs/security/features/trusty/download-and-build

tests/ui/check-cfg/well-known-values.stderr

@@ -6,7 +6,7 @@ LL | #[cfg(target_os = "linuz")]
    |                   |
    |                   help: did you mean: `"linux"`
    |
-   = note: expected values for `target_os` are: aix, android, cuda, dragonfly, emscripten, espidf, freebsd, fuchsia, haiku, hermit, horizon, illumos, ios, l4re, linux, macos, netbsd, none, nto, openbsd, psp, redox, solaris, solid_asp3, tvos, uefi, unknown, vita, vxworks, wasi, watchos, windows, xous
+   = note: expected values for `target_os` are: aix, android, cuda, dragonfly, emscripten, espidf, freebsd, fuchsia, haiku, hermit, horizon, illumos, ios, l4re, linux, macos, netbsd, none, nto, openbsd, psp, redox, solaris, solid_asp3, trusty, tvos, uefi, unknown, vita, vxworks, wasi, watchos, windows, xous
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: unexpected `cfg` condition value