rewrite no-alloc-shim to rmake

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -14,7 +14,6 @@ run-make/libtest-junit/Makefile
 run-make/libtest-thread-limit/Makefile
 run-make/macos-deployment-target/Makefile
 run-make/native-link-modifier-bundle/Makefile
-run-make/no-alloc-shim/Makefile
 run-make/reproducible-build/Makefile
 run-make/rlib-format-packed-bundled-libs/Makefile
 run-make/split-debuginfo/Makefile

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

@@ -1,10 +1,10 @@
-// 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
 
 //@ only-linux
-// Reason: this test is target-independent, considering compilation is targeted
+// Reason: this test is specific to linux, considering compilation is targeted
 // towards linux architectures only.
 
 use run_make_support::{assert_count_is, llvm_components_contain, rfs, rustc};

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

@@ -0,0 +1,55 @@
+// 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")
+    });
+    let compiler_builtins_libs = shallow_find_files(libdir, |path| {
+        has_prefix(path, "libcompiler_builtins") && has_extension(path, "rlib")
+    });
+
+    cc().input("foo.o")
+        .out_exe("foo")
+        .args(&alloc_libs)
+        .args(&core_libs)
+        .args(&compiler_builtins_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)
+        .args(&compiler_builtins_libs)
+        .run_fail();
+}