rewrite pgo-branch-weights (1/2)

Author: Oneirical

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

@@ -6,7 +6,7 @@
 pub mod cc;
 pub mod clang;
 pub mod diff;
-pub mod llvm_readobj;
+pub mod llvm;
 pub mod run;
 pub mod rustc;
 pub mod rustdoc;
@@ -23,7 +23,7 @@ pub use wasmparser;
 pub use cc::{cc, extra_c_flags, extra_cxx_flags, Cc};
 pub use clang::{clang, Clang};
 pub use diff::{diff, Diff};
-pub use llvm_readobj::{llvm_readobj, LlvmReadobj};
+pub use llvm::{llvm_profdata, llvm_readobj, LlvmProfdata, LlvmReadobj};
 pub use run::{run, run_fail};
 pub use rustc::{aux_build, rustc, Rustc};
 pub use rustdoc::{bare_rustdoc, rustdoc, Rustdoc};

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

@@ -0,0 +1,102 @@
+use std::env;
+use std::path::{Path, PathBuf};
+use std::process::Command;
+
+use crate::handle_failed_output;
+
+/// Construct a new `llvm-readobj` invocation. This assumes that `llvm-readobj` is available
+/// at `$LLVM_BIN_DIR/llvm-readobj`.
+pub fn llvm_readobj() -> LlvmReadobj {
+    LlvmReadobj::new()
+}
+
+/// Construct a new `llvm-profdata` invocation. This assumes that `llvm-profdata` is available
+/// at `$LLVM_BIN_DIR/llvm-profdata`.
+pub fn llvm_profdata() -> LlvmProfdata {
+    LlvmProfdata::new()
+}
+
+/// A `llvm-readobj` invocation builder.
+#[derive(Debug)]
+pub struct LlvmReadobj {
+    cmd: Command,
+}
+
+/// A `llvm-profdata` invocation builder.
+#[derive(Debug)]
+pub struct LlvmProfdata {
+    cmd: Command,
+}
+
+crate::impl_common_helpers!(LlvmReadobj);
+
+/// Generate the path to the bin directory of LLVM.
+pub fn llvm_bin_dir() -> PathBuf {
+    let llvm_bin_dir = env::var("LLVM_BIN_DIR")
+    .expect("`LLVM_BIN_DIR` not specified, but this is required to find `llvm-readobj`");
+    PathBuf::from(llvm_bin_dir);
+}
+
+impl LlvmReadobj {
+    /// Construct a new `llvm-readobj` invocation. This assumes that `llvm-readobj` is available
+    /// at `$LLVM_BIN_DIR/llvm-readobj`.
+    pub fn new() -> Self {
+        let llvm_readobj = llvm_bin_dir().join("llvm-readobj");
+        let cmd = Command::new(llvm_readobj);
+        Self { cmd }
+    }
+
+    /// Provide an input file.
+    pub fn input<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        self.cmd.arg(path.as_ref());
+        self
+    }
+
+    /// Pass `--file-header` to display file headers.
+    pub fn file_header(&mut self) -> &mut Self {
+        self.cmd.arg("--file-header");
+        self
+    }
+
+    /// Get the [`Output`][::std::process::Output] of the finished process.
+    #[track_caller]
+    pub fn command_output(&mut self) -> ::std::process::Output {
+        self.cmd.output().expect("failed to get output of finished process")
+    }
+}
+
+impl LlvmProfdata {
+    /// Construct a new `llvm-profdata` invocation. This assumes that `llvm-profdata` is available
+    /// at `$LLVM_BIN_DIR/llvm-profdata`.
+    pub fn new() -> Self {
+        let llvm_profdata = llvm_bin_dir().join("llvm-profdata");
+        let cmd = Command::new(llvm_profdata);
+        Self { cmd }
+    }
+
+    /// Provide an input file.
+    pub fn input<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        self.cmd.arg("-o");
+        self.cmd.arg(path.as_ref());
+        self
+    }
+
+    /// Specify the output file path.
+    pub fn output<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        self.cmd.arg(path.as_ref());
+        self
+    }
+
+    /// Take several profile data files generated by PGO instrumentation and merge them
+    /// together into a single indexed profile data file.
+    pub fn merge(&mut self) -> &mut Self {
+        self.cmd.arg("merge");
+        self
+    }
+
+    /// Get the [`Output`][::std::process::Output] of the finished process.
+    #[track_caller]
+    pub fn command_output(&mut self) -> ::std::process::Output {
+        self.cmd.output().expect("failed to get output of finished process")
+    }
+}

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

@@ -125,6 +125,24 @@ impl Rustc {
         self
     }
 
+    /// Specify directory path used for profile generation
+    pub fn profile_generate<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        let mut arg = OsString::new();
+        arg.push("-Cprofile-generate=");
+        arg.push(path.as_ref());
+        self.cmd.arg(&arg);
+        self
+    }
+
+    /// Specify directory path used for profile usage
+    pub fn profile_use<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        let mut arg = OsString::new();
+        arg.push("-Cprofile-use=");
+        arg.push(path.as_ref());
+        self.cmd.arg(&arg);
+        self
+    }
+
     /// Specify error format to use
     pub fn error_format(&mut self, format: &str) -> &mut Self {
         self.cmd.arg(format!("--error-format={format}"));

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

@@ -0,0 +1,44 @@
+// This test generates an instrumented binary - a program which
+// will keep track of how many times it calls each function, a useful
+// feature for optimization. Then, an argument (aaaaaaaaaaaa2bbbbbbbbbbbb2bbbbbbbbbbbbbbbbcc)
+// is passed into the instrumented binary, which should react with a number of function calls
+// fully known in advance. (For example, the letter 'a' results in calling f1())
+
+// If the test passes, the expected function call count was added to the use-phase LLVM-IR.
+// See https://github.com/rust-lang/rust/pull/66631
+
+use run_make_support::{run, rustc, tmp_dir};
+
+fn main() {
+    let common_flags = if env::consts::OS == "linux" && env::var("TARGET").unwrap_or_default().contains("x86") {
+        "-Clink-args=-fuse-ld=gold" // FIXME, Why was there a comma at the start?
+    } else {
+        ""
+    };
+    let path_prof_data_dir = tmp_dir().join("prof_data_dir");
+    let path_merged_profdata = path_prof_data_dir.clone().join("merged.profdata");
+    rustc().arg(common_flags).input("opaque.rs").run();
+    fs::create_dir_all(&path_prof_data_dir);
+    rustc().arg(common_flags)
+        .input("interesting.rs")
+        .profile_generate(&path_prof_data_dir)
+        .opt()
+        .codegen_units(1)
+        .run();
+    rustc().arg(common_flags)
+        .input("main.rs")
+        .profile_generate(&path_prof_data_dir)
+        .opt()
+        .run();
+    run("main aaaaaaaaaaaa2bbbbbbbbbbbb2bbbbbbbbbbbbbbbbcc"); // FIXME, with an arg? How to pass it?
+    llvm_profdata().merge().output(&path_merged_profdata).input(path_prof_data_dir).command_output();
+    rustc().arg(common_flags)
+        .input("interesting.rs")
+        .profile_use(path_merged_profdata)
+        .opt()
+        .codegen_units(1)
+        .emit("llvm-ir")
+        .run();
+    // FIXME, implement cat
+}
+