diff --git a/llvm/include/llvm/Support/FileSystem.h b/llvm/include/llvm/Support/FileSystem.h
--- a/llvm/include/llvm/Support/FileSystem.h
+++ b/llvm/include/llvm/Support/FileSystem.h
@@ -648,6 +648,14 @@
 /// A version for when a file descriptor is already available.
 std::error_code status(int FD, file_status &Result);
 
+/// Get file creation mode mask of the process.
+///
+/// @returns Mask reported by umask(2)
+/// @note There is no umask on Windows. This function returns 0 always
+///       on Windows. This function does not return an error_code because
+///       umask(2) never fails.
+unsigned getUmask();
+
 /// Set file permissions.
 ///
 /// @param Path File to set permissions on.
@@ -657,7 +665,8 @@
 /// @note On Windows, all permissions except *_write are ignored. Using any of
 ///       owner_write, group_write, or all_write will make the file writable.
 ///       Otherwise, the file will be marked as read-only.
-std::error_code setPermissions(const Twine &Path, perms Permissions);
+std::error_code setPermissions(const Twine &Path, perms Permissions,
+                               bool RespectUmask = false);
 
 /// Get file permissions.
 ///
diff --git a/llvm/lib/Support/Unix/Path.inc b/llvm/lib/Support/Unix/Path.inc
--- a/llvm/lib/Support/Unix/Path.inc
+++ b/llvm/lib/Support/Unix/Path.inc
@@ -691,10 +691,23 @@
   return fillStatus(StatRet, Status, Result);
 }
 
-std::error_code setPermissions(const Twine &Path, perms Permissions) {
+unsigned getUmask() {
+  // Chose arbitary new mask and ret set the umask to the old mask.
+  // umask(2) never fails so ignore the return of the second call.
+  unsigned Mask = ::umask(0);
+  (void) ::umask(Mask);
+  return Mask;
+}
+
+std::error_code setPermissions(const Twine &Path, perms Permissions, bool RespectUmask) {
   SmallString<128> PathStorage;
   StringRef P = Path.toNullTerminatedStringRef(PathStorage);
 
+  if (RespectUmask) {
+    unsigned Mask = getUmask();
+    Permissions = static_cast<perms>(Permissions & ~Mask);
+  }
+
   if (::chmod(P.begin(), Permissions))
     return std::error_code(errno, std::generic_category());
   return std::error_code();
diff --git a/llvm/lib/Support/Windows/Path.inc b/llvm/lib/Support/Windows/Path.inc
--- a/llvm/lib/Support/Windows/Path.inc
+++ b/llvm/lib/Support/Windows/Path.inc
@@ -734,7 +734,11 @@
   return getStatus(FileHandle, Result);
 }
 
-std::error_code setPermissions(const Twine &Path, perms Permissions) {
+unsigned getUmask() {
+  return 0;
+}
+
+std::error_code setPermissions(const Twine &Path, perms Permissions, bool /*RespectUmask*/) {
   SmallVector<wchar_t, 128> PathUTF16;
   if (std::error_code EC = widenPath(Path, PathUTF16))
     return EC;
diff --git a/llvm/unittests/Support/Path.cpp b/llvm/unittests/Support/Path.cpp
--- a/llvm/unittests/Support/Path.cpp
+++ b/llvm/unittests/Support/Path.cpp
@@ -1526,6 +1526,51 @@
   EXPECT_EQ(TestDirectoryIsLocal, TempFileIsLocal);
 }
 
+TEST_F(FileSystemTest, getUmask) {
+#ifdef _WIN32
+  EXPECT_EQ(fs::getUmask(), 0U) << "Should always be 0 on Windows.";
+#else
+  unsigned OldMask = ::umask(0022);
+  unsigned CurrentMask = fs::getUmask();
+  EXPECT_EQ(CurrentMask, 0022U)
+      << "getUmask() didn't return previously set umask()";
+  EXPECT_EQ(::umask(OldMask), 0022) << "getUmask() may have changed umask()";
+#endif
+}
+
+TEST_F(FileSystemTest, RespectUmask) {
+#ifndef _WIN32
+  unsigned OldMask = ::umask(0022);
+
+  int FD;
+  SmallString<128> TempPath;
+  ASSERT_NO_ERROR(fs::createTemporaryFile("prefix", "temp", FD, TempPath));
+
+  fs::perms AllRWE = static_cast<fs::perms>(0777);
+
+  ASSERT_NO_ERROR(fs::setPermissions(TempPath, AllRWE /*respectUmask=false*/));
+
+  ErrorOr<fs::perms> Perms = fs::getPermissions(TempPath);
+  ASSERT_TRUE(!!Perms);
+  EXPECT_EQ(Perms.get(), AllRWE) << "setPermissions respects on default";
+
+  ASSERT_NO_ERROR(fs::setPermissions(TempPath, AllRWE, /*respectUmask=*/true));
+  Perms = fs::getPermissions(TempPath);
+  ASSERT_TRUE(!!Perms);
+  EXPECT_EQ(Perms.get(), static_cast<fs::perms>(0755)) << "Did not respect Umask";
+
+  (void)::umask(0057);
+
+  ASSERT_NO_ERROR(fs::setPermissions(TempPath, AllRWE, /*respectUmask=*/true));
+  Perms = fs::getPermissions(TempPath);
+  ASSERT_TRUE(!!Perms);
+  EXPECT_EQ(Perms.get(), static_cast<fs::perms>(0720)) << "Did not respect Umask";
+
+  (void)::umask(OldMask);
+  (void)::close(FD);
+#endif
+}
+
 TEST_F(FileSystemTest, set_current_path) {
   SmallString<128> path;