rewrite target-specs to rmake

Author: Oneirical

tests/run-make/target-specs/Makefile

@@ -0,0 +1,71 @@
+// Target-specific compilation in rustc used to have case-by-case peculiarities in 2014,
+// with the compiler having redundant target types and unspecific names. An overarching rework
+// in #161156 changed the way the target flag functions, and this test attempts compilation
+// with the target flag's bundle of new features to check that compilation either succeeds while
+// using them correctly, or fails with the right error message when using them improperly.
+// See https://github.com/rust-lang/rust/pull/16156
+
+use run_make_support::{diff, fs_wrapper, rustc};
+
+fn main() {
+    rustc().input("foo.rs").target("my-awesome-platform.json").crate_type("lib").emit("asm").run();
+    assert!(!fs_wrapper::read_to_string("foo.s").contains("morestack"));
+    rustc()
+        .input("foo.rs")
+        .target("my-invalid-platform.json")
+        .run_fail()
+        .assert_stderr_contains("Error loading target specification");
+    rustc()
+        .input("foo.rs")
+        .target("my-incomplete-platform.json")
+        .run_fail()
+        .assert_stderr_contains("Field llvm-target");
+    rustc()
+        .env("RUST_TARGET_PATH", ".")
+        .input("foo.rs")
+        .target("my-awesome-platform")
+        .crate_type("lib")
+        .emit("asm")
+        .run();
+    rustc()
+        .env("RUST_TARGET_PATH", ".")
+        .input("foo.rs")
+        .target("my-x86_64-unknown-linux-gnu-platform")
+        .crate_type("lib")
+        .emit("asm")
+        .run();
+    let test_platform = rustc()
+        .arg("-Zunstable-options")
+        .target("my-awesome-platform.json")
+        .print("target-spec-json")
+        .run()
+        .stdout_utf8();
+    fs_wrapper::create_file("test-platform.json");
+    fs_wrapper::write("test-platform.json", test_platform.as_bytes());
+    let test_platform_2 = rustc()
+        .arg("-Zunstable-options")
+        .target("test-platform.json")
+        .print("target-spec-json")
+        .run()
+        .stdout_utf8();
+    diff()
+        .expected_file("test-platform.json")
+        .actual_text("test-platform-2", test_platform_2)
+        .run();
+    rustc()
+        .input("foo.rs")
+        .target("definitely-not-builtin-target")
+        .run_fail()
+        .assert_stderr_contains("may not set is_builtin");
+    rustc()
+        .input("foo.rs")
+        .target("endianness-mismatch")
+        .run_fail()
+        .assert_stderr_contains(r#""data-layout" claims architecture is little-endian"#);
+    rustc()
+        .input("foo.rs")
+        .target("mismatching-data-layout")
+        .crate_type("lib")
+        .run_fail()
+        .assert_stderr_contains("data-layout for target");
+}