Rollup merge of #128636 - folkertdev:rmake-thumb-none-cortex-m, r=jieyouxu

migrate `thumb-none-cortex-m` to rmake

tracking issue: https://github.com/rust-lang/rust/issues/121876

I'll leave some comments/questions inline

r? ```@jieyouxu```

try-job: armhf-gnu
try-job: dist-various-1
try-job: test-various

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -23,7 +23,6 @@ run-make/split-debuginfo/Makefile
 run-make/staticlib-dylib-linkage/Makefile
 run-make/symbol-mangling-hashed/Makefile
 run-make/sysroot-crates-are-unstable/Makefile
-run-make/thumb-none-cortex-m/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-cortex-m/Makefile

@@ -1,38 +0,0 @@
-include ../tools.mk
-
-# How to run this
-# $ ./x.py clean
-# $ ./x.py test --target thumbv6m-none-eabi,thumbv7m-none-eabi tests/run-make
-
-# Supported targets:
-# - thumbv6m-none-eabi (Bare Cortex-M0, M0+, M1)
-# - thumbv7em-none-eabi (Bare Cortex-M4, M7)
-# - thumbv7em-none-eabihf (Bare Cortex-M4F, M7F, FPU, hardfloat)
-# - thumbv7m-none-eabi (Bare Cortex-M3)
-
-# only-thumb
-
-# For cargo setting
-RUSTC := $(RUSTC_ORIGINAL)
-LD_LIBRARY_PATH := $(HOST_RPATH_DIR)
-# We need to be outside of 'src' dir in order to run cargo
-WORK_DIR := $(TMPDIR)
-
-HERE := $(shell pwd)
-
-CRATE := cortex-m
-CRATE_URL := https://github.com/rust-embedded/cortex-m
-CRATE_SHA1 := a448e9156e2cb1e556e5441fd65426952ef4b927 # 0.5.0
-
-# Don't make lints fatal, but they need to at least warn or they break Cargo's target info parsing.
-export RUSTFLAGS := --cap-lints=warn
-
-all:
-	env
-	mkdir -p $(WORK_DIR)
-	-cd $(WORK_DIR) && rm -rf $(CRATE)
-	cd $(WORK_DIR) && bash -x $(HERE)/../git_clone_sha1.sh $(CRATE) $(CRATE_URL) $(CRATE_SHA1)
-	# HACK(eddyb) sets `RUSTC_BOOTSTRAP=1` so Cargo can accept nightly features.
-	# These come from the top-level Rust workspace, that this crate is not a
-	# member of, but Cargo tries to load the workspace `Cargo.toml` anyway.
-	cd $(WORK_DIR) && cd $(CRATE) && env RUSTC_BOOTSTRAP=1 $(BOOTSTRAP_CARGO) build --target $(TARGET) -v

tests/run-make/thumb-none-cortex-m/rmake.rs

@@ -0,0 +1,59 @@
+//! Test building of the `cortex-m` crate, a foundational crate in the embedded ecosystem
+//! for a collection of thumb targets. This is a smoke test that verifies that both cargo
+//! and rustc work in this case.
+//!
+//! How to run this
+//! $ ./x.py clean
+//! $ ./x.py test --target thumbv6m-none-eabi,thumbv7m-none-eabi tests/run-make
+//!
+//! Supported targets:
+//! - thumbv6m-none-eabi (Bare Cortex-M0, M0+, M1)
+//! - thumbv7em-none-eabi (Bare Cortex-M4, M7)
+//! - thumbv7em-none-eabihf (Bare Cortex-M4F, M7F, FPU, hardfloat)
+//! - thumbv7m-none-eabi (Bare Cortex-M3)
+
+//@ only-thumb
+
+use std::path::PathBuf;
+
+use run_make_support::rfs::create_dir;
+use run_make_support::{cmd, env_var, target};
+
+const CRATE: &str = "cortex-m";
+const CRATE_URL: &str = "https://github.com/rust-embedded/cortex-m";
+const CRATE_SHA1: &str = "a448e9156e2cb1e556e5441fd65426952ef4b927"; // v0.5.0
+
+fn main() {
+    // FIXME: requires an internet connection https://github.com/rust-lang/rust/issues/128733
+    // See below link for git usage:
+    // https://stackoverflow.com/questions/3489173#14091182
+    cmd("git").args(["clone", CRATE_URL, CRATE]).run();
+    std::env::set_current_dir(CRATE).unwrap();
+    cmd("git").args(["reset", "--hard", CRATE_SHA1]).run();
+
+    let target_dir = PathBuf::from("target");
+    let manifest_path = PathBuf::from("Cargo.toml");
+
+    let path = env_var("PATH");
+    let rustc = env_var("RUSTC");
+    let bootstrap_cargo = env_var("BOOTSTRAP_CARGO");
+    // FIXME: extract bootstrap cargo invocations to a proper command
+    // https://github.com/rust-lang/rust/issues/128734
+    let mut cmd = cmd(bootstrap_cargo);
+    cmd.args(&[
+        "build",
+        "--manifest-path",
+        manifest_path.to_str().unwrap(),
+        "-Zbuild-std=core",
+        "--target",
+        &target(),
+    ])
+    .env("PATH", path)
+    .env("RUSTC", rustc)
+    .env("CARGO_TARGET_DIR", &target_dir)
+    // Don't make lints fatal, but they need to at least warn
+    // or they break Cargo's target info parsing.
+    .env("RUSTFLAGS", "-Copt-level=0 -Cdebug-assertions=yes --cap-lints=warn");
+
+    cmd.run();
+}