rewrite pgo-gen to rmake

Author: Oneirical

src/tools/run-make-support/src/lib.rs

@@ -247,6 +247,34 @@ pub fn test_while_readonly<P: AsRef<Path>, F: FnOnce() + std::panic::UnwindSafe>
     success.unwrap();
 }
 
+/// Browse the directory `path` non-recursively and return the first file path which starts with `prefix` and has the
+/// file extension `extension`.
+#[track_caller]
+pub fn find_files_by_prefix_and_extension<P: AsRef<Path>>(
+    path: P,
+    prefix: &str,
+    extension: &str,
+) -> Vec<PathBuf> {
+    let mut matching_files = Vec::new();
+    for entry in fs_wrapper::read_dir(path) {
+        let entry = entry.expect("failed to read directory entry.");
+        let path = entry.path();
+
+        if path.is_file()
+            && path.file_name().unwrap().to_str().unwrap().starts_with(prefix)
+            && path.extension().unwrap().to_str().unwrap() == extension
+        {
+            matching_files.push(path);
+        }
+    }
+
+    if matching_files.is_empty() {
+        panic!("no files found with the given prefix and extension");
+    } else {
+        matching_files
+    }
+}
+
 /// Use `cygpath -w` on a path to get a Windows path string back. This assumes that `cygpath` is
 /// available on the platform!
 #[track_caller]

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -132,7 +132,6 @@ run-make/pdb-alt-path/Makefile
 run-make/pdb-buildinfo-cl-cmd/Makefile
 run-make/pgo-gen-lto/Makefile
 run-make/pgo-gen-no-imp-symbols/Makefile
-run-make/pgo-gen/Makefile
 run-make/pgo-indirect-call-promotion/Makefile
 run-make/pgo-use/Makefile
 run-make/pointer-auth-link-with-c/Makefile

tests/run-make/pgo-gen/Makefile

@@ -0,0 +1,18 @@
+// -C profile-generate, when used with rustc, is supposed to output
+// profile files (.profraw) after running a binary to analyze how the compiler
+// optimizes code. This test checks that these files are generated.
+// See https://github.com/rust-lang/rust/pull/48346
+
+//@ needs-profiler-support
+//@ ignore-cross-compile
+
+use run_make_support::{cwd, find_files_by_prefix_and_extension, run, rustc};
+
+fn main() {
+    rustc().arg("-g").profile_generate(cwd()).run();
+    run("test");
+    assert!(
+        find_files_by_prefix_and_extension(cwd(), "default", "profraw").len() > 0,
+        "no .profraw file generated"
+    );
+}