3 files changed, 115 insertions, 0 deletions
diff --git a/library/profiler_builtins/Cargo.toml b/library/profiler_builtins/Cargo.toml
new file mode 100644
index 000000000..3371dfa12
--- /dev/null
+++ b/library/profiler_builtins/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "profiler_builtins"
+version = "0.0.0"
+edition = "2021"
+
+[lib]
+test = false
+bench = false
+doc = false
+
+[dependencies]
+core = { path = "../core" }
+compiler_builtins = { version = "0.1.0", features = ['rustc-dep-of-std'] }
+
+[build-dependencies]
+cc = "1.0.69"
diff --git a/library/profiler_builtins/build.rs b/library/profiler_builtins/build.rs
new file mode 100644
index 000000000..1b1f11798
--- /dev/null
+++ b/library/profiler_builtins/build.rs
@@ -0,0 +1,89 @@
+//! Compiles the profiler part of the `compiler-rt` library.
+//!
+//! See the build.rs for libcompiler_builtins crate for details.
+
+use std::env;
+use std::path::Path;
+
+fn main() {
+    let target = env::var("TARGET").expect("TARGET was not set");
+    let cfg = &mut cc::Build::new();
+
+    // FIXME: `rerun-if-changed` directives are not currently emitted and the build script
+    // will not rerun on changes in these source files or headers included into them.
+    let mut profile_sources = vec![
+        "GCDAProfiling.c",
+        "InstrProfiling.c",
+        "InstrProfilingBuffer.c",
+        "InstrProfilingFile.c",
+        "InstrProfilingMerge.c",
+        "InstrProfilingMergeFile.c",
+        "InstrProfilingNameVar.c",
+        "InstrProfilingPlatformDarwin.c",
+        "InstrProfilingPlatformFuchsia.c",
+        "InstrProfilingPlatformLinux.c",
+        "InstrProfilingPlatformOther.c",
+        "InstrProfilingPlatformWindows.c",
+        "InstrProfilingRuntime.cpp",
+        "InstrProfilingUtil.c",
+        "InstrProfilingValue.c",
+        "InstrProfilingVersionVar.c",
+        "InstrProfilingWriter.c",
+        // These files were added in LLVM 11.
+        "InstrProfilingInternal.c",
+        "InstrProfilingBiasVar.c",
+    ];
+
+    if target.contains("msvc") {
+        // Don't pull in extra libraries on MSVC
+        cfg.flag("/Zl");
+        profile_sources.push("WindowsMMap.c");
+        cfg.define("strdup", Some("_strdup"));
+        cfg.define("open", Some("_open"));
+        cfg.define("fdopen", Some("_fdopen"));
+        cfg.define("getpid", Some("_getpid"));
+        cfg.define("fileno", Some("_fileno"));
+    } else {
+        // Turn off various features of gcc and such, mostly copying
+        // compiler-rt's build system already
+        cfg.flag("-fno-builtin");
+        cfg.flag("-fomit-frame-pointer");
+        cfg.define("VISIBILITY_HIDDEN", None);
+        if !target.contains("windows") {
+            cfg.flag("-fvisibility=hidden");
+            cfg.define("COMPILER_RT_HAS_UNAME", Some("1"));
+        } else {
+            profile_sources.push("WindowsMMap.c");
+        }
+    }
+
+    // Assume that the Unixes we are building this for have fnctl() available
+    if env::var_os("CARGO_CFG_UNIX").is_some() {
+        cfg.define("COMPILER_RT_HAS_FCNTL_LCK", Some("1"));
+    }
+
+    // This should be a pretty good heuristic for when to set
+    // COMPILER_RT_HAS_ATOMICS
+    if env::var_os("CARGO_CFG_TARGET_HAS_ATOMIC")
+        .map(|features| features.to_string_lossy().to_lowercase().contains("ptr"))
+        .unwrap_or(false)
+    {
+        cfg.define("COMPILER_RT_HAS_ATOMICS", Some("1"));
+    }
+
+    // Note that this should exist if we're going to run (otherwise we just
+    // don't build profiler builtins at all).
+    let root = Path::new("../../src/llvm-project/compiler-rt");
+
+    let src_root = root.join("lib").join("profile");
+    for src in profile_sources {
+        let path = src_root.join(src);
+        if path.exists() {
+            cfg.file(path);
+        }
+    }
+
+    cfg.include(root.join("include"));
+    cfg.warnings(false);
+    cfg.compile("profiler-rt");
+}
diff --git a/library/profiler_builtins/src/lib.rs b/library/profiler_builtins/src/lib.rs
new file mode 100644
index 000000000..0c83bcee0
--- /dev/null
+++ b/library/profiler_builtins/src/lib.rs
@@ -0,0 +1,10 @@
+#![no_std]
+#![feature(profiler_runtime)]
+#![profiler_runtime]
+#![unstable(
+    feature = "profiler_runtime_lib",
+    reason = "internal implementation detail of rustc right now",
+    issue = "none"
+)]
+#![allow(unused_features)]
+#![feature(staged_api)]