Auto merge of #128361 - Oneirical:testle-deforestation, r=<try>

Migrate `link-cfg` and `rustdoc-default-output` `run-make` tests to rmake

Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).

try-job: aarch64-apple
try-job: x86_64-msvc
try-job: x86_64-mingw
try-job: x86_64-gnu-llvm-18
try-job: i686-msvc

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -19,13 +19,11 @@ run-make/issue-36710/Makefile
 run-make/issue-47551/Makefile
 run-make/issue-69368/Makefile
 run-make/issue-84395-lto-embed-bitcode/Makefile
-run-make/issue-88756-default-output/Makefile
 run-make/jobserver-error/Makefile
 run-make/libs-through-symlinks/Makefile
 run-make/libtest-json/Makefile
 run-make/libtest-junit/Makefile
 run-make/libtest-thread-limit/Makefile
-run-make/link-cfg/Makefile
 run-make/long-linker-command-lines-cmd-exe/Makefile
 run-make/long-linker-command-lines/Makefile
 run-make/macos-deployment-target/Makefile

tests/run-make/link-cfg/rmake.rs

@@ -0,0 +1,43 @@
+// The `#[link(cfg(..))]` annotation means that the `#[link]`
+// directive is only active in a compilation unit if that `cfg` value is satisfied.
+// For example, when compiling an rlib, these directives are just encoded and
+// ignored for dylibs, and all staticlibs are continued to be put into the rlib as
+// usual. When placing that rlib into a staticlib, executable, or dylib, however,
+// the `cfg` is evaluated *as if it were defined in the final artifact* and the
+// library is decided to be linked or not.
+// This test exercises this new feature by testing it with no dependencies, then
+// with only dynamic libraries, then with both a staticlib and dylibs. Compilation
+// and execution should be successful.
+// See https://github.com/rust-lang/rust/pull/37545
+
+//@ ignore-cross-compile
+// Reason: the compiled binary is executed
+
+use run_make_support::{bare_rustc, build_native_dynamic_lib, build_native_static_lib, run, rustc};
+
+fn main() {
+    build_native_dynamic_lib("return1");
+    build_native_dynamic_lib("return2");
+    build_native_static_lib("return3");
+    bare_rustc()
+        .print("cfg")
+        .target("x86_64-unknown-linux-musl")
+        .run()
+        .assert_stdout_contains("crt-static");
+    rustc().input("no-deps.rs").cfg("foo").run();
+    run("no-deps");
+    rustc().input("no-deps.rs").cfg("bar").run();
+    run("no-deps");
+
+    rustc().input("dep.rs").run();
+    rustc().input("with-deps.rs").cfg("foo").run();
+    run("with-deps");
+    rustc().input("with-deps.rs").cfg("bar").run();
+    run("with-deps");
+
+    rustc().input("dep-with-staticlib.rs").run();
+    rustc().input("with-staticlib-deps.rs").cfg("foo").run();
+    run("with-staticlib-deps");
+    rustc().input("with-staticlib-deps.rs").cfg("bar").run();
+    run("with-staticlib-deps");
+}

tests/run-make/rustdoc-default-output/rmake.rs

@@ -0,0 +1,16 @@
+// Calling rustdoc with no arguments, which should bring up a help menu, used to
+// cause an error as rustdoc expects an input file. Fixed in #98331, this test
+// ensures the output of rustdoc's help menu is as expected.
+// See https://github.com/rust-lang/rust/issues/88756
+
+use run_make_support::{bare_rustdoc, diff};
+
+fn main() {
+    let out = bare_rustdoc().run().stdout_utf8();
+    diff()
+        .expected_file("output-default.stdout")
+        .actual_text("actual", out)
+        // replace the channel type in the URL with $CHANNEL
+        .normalize(r"/nightly/|beta/|stable/|1\.[0-9]+\.[0-9]+/", "/$$CHANNEL/")
+        .run();
+}