From cb56b52b9a33f0a49796281635d280de26a3d5b1 Mon Sep 17 00:00:00 2001
From: Hadi Ravanbakhsh <ravanbakhsh@google.com>
Date: Thu, 21 Nov 2024 06:11:03 -0800
Subject: [PATCH] Update crashing input modification time to keep track of
 reproducibility checks.

PiperOrigin-RevId: 698753304
---
 centipede/centipede_interface.cc |  2 ++
 common/BUILD                     |  1 +
 common/remote_file.h             |  3 +++
 common/remote_file_oss.cc        | 20 ++++++++++++++++++++
 common/remote_file_test.cc       | 21 +++++++++++++++++++++
 5 files changed, 47 insertions(+)

diff --git a/centipede/centipede_interface.cc b/centipede/centipede_interface.cc
index aa3e2eda..d527b775 100644
--- a/centipede/centipede_interface.cc
+++ b/centipede/centipede_interface.cc
@@ -392,6 +392,8 @@ absl::flat_hash_set<std::string> PruneOldCrashesAndGetRemainingCrashMetadata(
              .second;
     if (!is_reproducible || is_duplicate) {
       CHECK_OK(RemotePathDelete(crashing_input_file, /*recursively=*/false));
+    } else {
+      CHECK_OK(RemotePathTouchExistingFile(crashing_input_file));
     }
   }
   return remaining_crash_metadata;
diff --git a/common/BUILD b/common/BUILD
index c13bda56..ed3c69a9 100644
--- a/common/BUILD
+++ b/common/BUILD
@@ -228,6 +228,7 @@ cc_library(
         ":remote_file",
         ":test_util",
         "@com_google_absl//absl/log:check",
+        "@com_google_absl//absl/time",
         "@com_google_googletest//:gtest",
     ],
     alwayslink = True,
diff --git a/common/remote_file.h b/common/remote_file.h
index 627109e2..b4ec099a 100644
--- a/common/remote_file.h
+++ b/common/remote_file.h
@@ -136,6 +136,9 @@ absl::StatusOr<std::vector<std::string>> RemoteListFiles(std::string_view path,
 // Renames `from` to `to`.
 absl::Status RemotePathRename(std::string_view from, std::string_view to);
 
+// Updates the last-modified time of `path` to the current time.
+absl::Status RemotePathTouchExistingFile(std::string_view path);
+
 // Deletes `path`. If `path` is a directory and `recursively` is true,
 // recursively deletes all files and subdirectories within `path`.
 absl::Status RemotePathDelete(std::string_view path, bool recursively);
diff --git a/common/remote_file_oss.cc b/common/remote_file_oss.cc
index bc511608..2ea73afe 100644
--- a/common/remote_file_oss.cc
+++ b/common/remote_file_oss.cc
@@ -181,6 +181,10 @@ absl::Status RemotePathRename(std::string_view from, std::string_view to) {
   LOG(FATAL) << "Filesystem API not supported in iOS/MacOS";
 }
 
+absl::Status RemotePathTouchExistingFile(std::string_view path) {
+  LOG(FATAL) << "Filesystem API not supported in iOS/MacOS";
+}
+
 absl::Status RemotePathDelete(std::string_view path, bool recursively) {
   LOG(FATAL) << "Filesystem API not supported in iOS/MacOS";
 }
@@ -238,6 +242,22 @@ absl::Status RemotePathRename(std::string_view from, std::string_view to) {
   return absl::OkStatus();
 }
 
+absl::Status RemotePathTouchExistingFile(std::string_view path) {
+  if (!RemotePathExists(path)) {
+    return absl::InvalidArgumentError(
+        absl::StrCat("path: ", std::string(path), " does not exist."));
+  }
+  std::error_code error;
+  std::filesystem::last_write_time(
+      path, std::filesystem::file_time_type::clock::now(), error);
+  if (error) {
+    return absl::UnknownError(absl::StrCat(
+        "filesystem::last_write_time() failed, path: ", std::string(path),
+        ", error: ", error.message()));
+  }
+  return absl::OkStatus();
+}
+
 absl::Status RemotePathDelete(std::string_view path, bool recursively) {
   std::error_code error;
   if (recursively) {
diff --git a/common/remote_file_test.cc b/common/remote_file_test.cc
index d0bc7214..62694146 100644
--- a/common/remote_file_test.cc
+++ b/common/remote_file_test.cc
@@ -24,6 +24,8 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "absl/log/check.h"
+#include "absl/time/clock.h"
+#include "absl/time/time.h"
 #include "./common/logging.h"
 #include "./common/test_util.h"
 
@@ -142,5 +144,24 @@ TEST(RemotePathDelete, RecursivelyDeletesAllFilesAndSubdirectories) {
   EXPECT_FALSE(fs::exists(a_b_c));
 }
 
+TEST(RemotePathTouchExistingFile, FailsWhenPathDoesNotExist) {
+  EXPECT_FALSE(RemotePathTouchExistingFile("/non/existent/path").ok());
+}
+
+TEST(RemotePathTouchExistingFile, UpdatesTheLastModifiedTime) {
+  const fs::path temp_dir = GetTestTempDir(test_info_->name());
+  const std::string file_path = temp_dir / "file";
+  CreateFileOrDie(file_path);
+
+  const auto start_time = std::filesystem::file_time_type::clock::now();
+  absl::SleepFor(absl::Milliseconds(1));
+  ASSERT_TRUE(RemotePathTouchExistingFile(file_path).ok());
+  const auto end_time = std::filesystem::file_time_type::clock::now();
+
+  const auto last_modified_time = fs::last_write_time(file_path);
+  ASSERT_LT(last_modified_time, end_time);
+  EXPECT_GT(last_modified_time, start_time);
+}
+
 }  // namespace
 }  // namespace centipede