From 925644ed09689018cd17b3bb6e469520d105e6b8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Ber=C3=A1nek?= <berykubik@gmail.com>
Date: Sat, 20 Aug 2022 13:40:18 +0200
Subject: [PATCH] Track PGO profiles in depinfo

---
 compiler/rustc_interface/src/passes.rs        | 17 +++++++++---
 src/test/run-make/track-pgo-dep-info/Makefile | 26 +++++++++++++++++++
 src/test/run-make/track-pgo-dep-info/main.rs  |  1 +
 3 files changed, 41 insertions(+), 3 deletions(-)
 create mode 100644 src/test/run-make/track-pgo-dep-info/Makefile
 create mode 100644 src/test/run-make/track-pgo-dep-info/main.rs

diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index e00d0b7d0d82f..149b3697d9101 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -593,13 +593,24 @@ fn write_out_deps(
         // Account for explicitly marked-to-track files
         // (e.g. accessed in proc macros).
         let file_depinfo = sess.parse_sess.file_depinfo.borrow();
-        let extra_tracked_files = file_depinfo.iter().map(|path_sym| {
-            let path = PathBuf::from(path_sym.as_str());
+
+        let normalize_path = |path: PathBuf| {
             let file = FileName::from(path);
             escape_dep_filename(&file.prefer_local().to_string())
-        });
+        };
+
+        let extra_tracked_files =
+            file_depinfo.iter().map(|path_sym| normalize_path(PathBuf::from(path_sym.as_str())));
         files.extend(extra_tracked_files);
 
+        // We also need to track used PGO profile files
+        if let Some(ref profile_instr) = sess.opts.cg.profile_use {
+            files.push(normalize_path(profile_instr.as_path().to_path_buf()));
+        }
+        if let Some(ref profile_sample) = sess.opts.unstable_opts.profile_sample_use {
+            files.push(normalize_path(profile_sample.as_path().to_path_buf()));
+        }
+
         if sess.binary_dep_depinfo() {
             if let Some(ref backend) = sess.opts.unstable_opts.codegen_backend {
                 if backend.contains('.') {
diff --git a/src/test/run-make/track-pgo-dep-info/Makefile b/src/test/run-make/track-pgo-dep-info/Makefile
new file mode 100644
index 0000000000000..60b59c04aa95c
--- /dev/null
+++ b/src/test/run-make/track-pgo-dep-info/Makefile
@@ -0,0 +1,26 @@
+# needs-profiler-support
+# ignore-windows-gnu
+
+-include ../../run-make-fulldeps/tools.mk
+
+# FIXME(eddyb) provide `HOST_RUSTC` and `TARGET_RUSTC`
+# instead of hardcoding them everywhere they're needed.
+ifeq ($(IS_MUSL_HOST),1)
+ADDITIONAL_ARGS := $(RUSTFLAGS)
+endif
+
+all:
+	# Generate PGO profiles
+	$(BARE_RUSTC) $(ADDITIONAL_ARGS) -Cprofile-generate=$(TMPDIR)/profiles --out-dir $(TMPDIR) main.rs
+	$(TMPDIR)/main
+
+	# Merge profiles
+	"$(LLVM_BIN_DIR)/llvm-profdata" merge \
+		-o "$(TMPDIR)/merged.profdata" \
+		"$(TMPDIR)/profiles" || exit 1
+
+	# Use the profile
+	$(RUSTC) -Cprofile-use=$(TMPDIR)/merged.profdata --emit dep-info main.rs
+
+	# Check that profile file is in depinfo
+	$(CGREP) "merged.profdata" < $(TMPDIR)/main.d
diff --git a/src/test/run-make/track-pgo-dep-info/main.rs b/src/test/run-make/track-pgo-dep-info/main.rs
new file mode 100644
index 0000000000000..f328e4d9d04c3
--- /dev/null
+++ b/src/test/run-make/track-pgo-dep-info/main.rs
@@ -0,0 +1 @@
+fn main() {}