rewrite cdylib-fewer-symbols to rmake

Author: Oneirical

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -9,7 +9,6 @@ run-make/c-unwind-abi-catch-lib-panic/Makefile
 run-make/c-unwind-abi-catch-panic/Makefile
 run-make/cat-and-grep-sanity-check/Makefile
 run-make/cdylib-dylib-linkage/Makefile
-run-make/cdylib-fewer-symbols/Makefile
 run-make/compiler-lookup-paths-2/Makefile
 run-make/compiler-lookup-paths/Makefile
 run-make/compiler-rt-works-on-mingw/Makefile

tests/run-make/cdylib-fewer-symbols/Makefile

@@ -0,0 +1,23 @@
+// Symbols related to the allocator should be hidden and not exported from a cdylib,
+// for they are internal to Rust
+// and not part of the public ABI (application binary interface). This test checks that
+// four such symbols are successfully hidden.
+// See https://github.com/rust-lang/rust/pull/45710
+
+//FIXME(Oneirical): try it on windows, restore ignore
+// See https://github.com/rust-lang/rust/pull/46207#issuecomment-347561753
+//FIXME(Oneirical): I also removed cross-compile ignore since there is no binary execution
+
+use run_make_support::{dynamic_lib_name, llvm_readobj, rustc};
+
+fn main() {
+    // Compile a cdylib
+    rustc().input("foo.rs").run();
+    let out = llvm_readobj().arg("--symbols").input(dynamic_lib_name("foo")).run().stdout_utf8();
+    let out = // All hidden symbols must be removed.
+        out.lines().filter(|&line| !line.trim().contains("HIDDEN")).collect::<Vec<_>>().join("\n");
+    assert!(!&out.contains("__rdl_"));
+    assert!(!&out.contains("__rde_"));
+    assert!(!&out.contains("__rg_"));
+    assert!(!&out.contains("__ruse_"));
+}