migrate thumb-none-qemu to rmake

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -22,6 +22,5 @@ run-make/rlib-format-packed-bundled-libs/Makefile
 run-make/split-debuginfo/Makefile
 run-make/symbol-mangling-hashed/Makefile
 run-make/sysroot-crates-are-unstable/Makefile
-run-make/thumb-none-qemu/Makefile
 run-make/translation/Makefile
 run-make/x86_64-fortanix-unknown-sgx-lvi/Makefile

tests/run-make/thumb-none-qemu/example/.cargo/config → tests/run-make/thumb-none-qemu/example/.cargo/config.toml

@@ -1,6 +1,5 @@
 [target.thumbv6m-none-eabi]
-# FIXME: Should be Cortex-M0, but Qemu used by CI is too old
-runner = "qemu-system-arm -cpu cortex-m3 -machine lm3s6965evb -nographic -semihosting-config enable=on,target=native -kernel"
+runner = "qemu-system-arm -cpu cortex-m0 -machine lm3s6965evb -nographic -semihosting-config enable=on,target=native -kernel"
 
 [target.thumbv7m-none-eabi]
 runner = "qemu-system-arm -cpu cortex-m3 -machine lm3s6965evb -nographic -semihosting-config enable=on,target=native -kernel"
@@ -12,7 +11,7 @@ runner = "qemu-system-arm -cpu cortex-m4 -machine lm3s6965evb -nographic -semiho
 runner = "qemu-system-arm -cpu cortex-m4 -machine lm3s6965evb -nographic -semihosting-config enable=on,target=native -kernel"
 
 [target.thumbv8m.base-none-eabi]
-# FIXME: Should be the Cortex-M23, bt Qemu does not currently support it
+# FIXME: Should be the Cortex-M23, but Qemu does not currently support it
 runner = "qemu-system-arm -cpu cortex-m33 -machine lm3s6965evb -nographic -semihosting-config enable=on,target=native -kernel"
 
 [target.thumbv8m.main-none-eabi]

tests/run-make/thumb-none-qemu/rmake.rs

@@ -0,0 +1,62 @@
+//! This test runs a basic application for thumb targets, using the cortex-m crate.
+//!
+//! These targets are very bare-metal: the first instruction the core runs on
+//! power-on is already user code. The cortex-m-rt has to initialize the stack, .data,
+//! .bss, enable the FPU if present, etc.
+//!
+//! This test builds and runs the applications for various thumb targets using qemu.
+//!
+//! How to run this
+//! $ ./x.py clean
+//! $ ./x.py test --target thumbv6m-none-eabi,thumbv7m-none-eabi tests/run-make
+//!
+//! For supported targets, see `example/.cargo/config.toml`
+//!
+//! FIXME: https://github.com/rust-lang/rust/issues/128733 this test uses external
+//! dependencies, and needs an active internet connection
+//!
+//! FIXME: https://github.com/rust-lang/rust/issues/128734 extract bootstrap cargo
+//! to a proper command
+
+//@ only-thumb
+
+use std::path::PathBuf;
+
+use run_make_support::{cmd, env_var, path_helpers, target};
+
+const CRATE: &str = "example";
+
+fn main() {
+    std::env::set_current_dir(CRATE).unwrap();
+
+    let bootstrap_cargo = env_var("BOOTSTRAP_CARGO");
+    let path = env_var("PATH");
+    let rustc = env_var("RUSTC");
+
+    let target_dir = path_helpers::path("target");
+    let manifest_path = path_helpers::path("Cargo.toml");
+
+    let debug = {
+        let mut cmd = cmd(&bootstrap_cargo);
+        cmd.args(&["run", "--target", &target()])
+            .env("RUSTFLAGS", "-C linker=arm-none-eabi-ld -C link-arg=-Tlink.x")
+            .env("CARGO_TARGET_DIR", &target_dir)
+            .env("PATH", &path)
+            .env("RUSTC", &rustc);
+        cmd.run()
+    };
+
+    debug.assert_stdout_contains("x = 42");
+
+    let release = {
+        let mut cmd = cmd(&bootstrap_cargo);
+        cmd.args(&["run", "--release", "--target", &target()])
+            .env("RUSTFLAGS", "-C linker=arm-none-eabi-ld -C link-arg=-Tlink.x")
+            .env("CARGO_TARGET_DIR", &target_dir)
+            .env("PATH", &path)
+            .env("RUSTC", &rustc);
+        cmd.run()
+    };
+
+    release.assert_stdout_contains("x = 42");
+}