rewrite no-alloc-shim to rmake

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -31,7 +31,6 @@ run-make/long-linker-command-lines/Makefile
 run-make/macos-deployment-target/Makefile
 run-make/native-link-modifier-bundle/Makefile
 run-make/native-link-modifier-whole-archive/Makefile
-run-make/no-alloc-shim/Makefile
 run-make/no-builtins-attribute/Makefile
 run-make/pdb-buildinfo-cl-cmd/Makefile
 run-make/pgo-gen-lto/Makefile

tests/run-make/min-global-align/rmake.rs

@@ -1,4 +1,4 @@
-// This tests ensure that global variables respect the target minimum alignment.
+// This test checks that global variables respect the target minimum alignment.
 // The three bools `STATIC_BOOL`, `STATIC_MUT_BOOL`, and `CONST_BOOL` all have
 // type-alignment of 1, but some targets require greater global alignment.
 // See https://github.com/rust-lang/rust/pull/44440

tests/run-make/no-alloc-shim/rmake.rs

@@ -0,0 +1,40 @@
+// This test checks the compatibility of the interaction between `--emit obj` and
+// `#[global_allocator]`, as it is now possible to invoke the latter without the
+// allocator shim since #86844. As this feature is unstable, it should fail if
+// --cfg check_feature_gate is passed.
+// See https://github.com/rust-lang/rust/pull/86844
+
+//@ ignore-cross-compile
+// Reason: the compiled binary is executed
+
+//@ ignore-msvc
+//FIXME(Oneirical): Getting this to work on MSVC requires passing libcmt.lib to CC,
+// which is not trivial to do.
+// Tracking issue: https://github.com/rust-lang/rust/issues/128602
+// Discussion: https://github.com/rust-lang/rust/pull/128407#discussion_r1702439172
+
+use run_make_support::{cc, cwd, has_extension, has_prefix, run, rustc, shallow_find_files};
+
+fn main() {
+    rustc().input("foo.rs").crate_type("bin").emit("obj").panic("abort").run();
+    let libdir = rustc().print("target-libdir").run().stdout_utf8();
+    let libdir = libdir.trim();
+    let alloc_libs = shallow_find_files(&libdir, |path| {
+        has_prefix(path, "liballoc-") && has_extension(path, "rlib")
+    });
+    let core_libs = shallow_find_files(libdir, |path| {
+        has_prefix(path, "libcore-") && has_extension(path, "rlib")
+    });
+    cc().input("foo.o").out_exe("foo").args(&alloc_libs).args(&core_libs).run();
+    run("foo");
+
+    // Check that linking without __rust_no_alloc_shim_is_unstable defined fails
+    rustc()
+        .input("foo.rs")
+        .crate_type("bin")
+        .emit("obj")
+        .panic("abort")
+        .cfg("check_feature_gate")
+        .run();
+    cc().input("foo.o").out_exe("foo").args(&alloc_libs).args(&core_libs).run_fail();
+}