Index: projects/compiler-rt/lib/sanitizer_common/sanitizer_file.cc
===================================================================
--- projects/compiler-rt/lib/sanitizer_common/sanitizer_file.cc
+++ projects/compiler-rt/lib/sanitizer_common/sanitizer_file.cc
@@ -59,6 +59,9 @@
   } else {
     internal_snprintf(full_path, kMaxPathLength, "%s.%zu", path_prefix, pid);
   }
+  if (common_flags()->log_suffix) {
+     internal_strlcat(full_path, common_flags()->log_suffix, kMaxPathLength);
+  }
   fd = OpenFile(full_path, WrOnly);
   if (fd == kInvalidFd) {
     const char *ErrorMsgPrefix = "ERROR: Can't open file: ";
Index: projects/compiler-rt/lib/sanitizer_common/sanitizer_flags.inc
===================================================================
--- projects/compiler-rt/lib/sanitizer_common/sanitizer_flags.inc
+++ projects/compiler-rt/lib/sanitizer_common/sanitizer_flags.inc
@@ -56,6 +56,9 @@
     "Mention name of executable when reporting error and "
     "append executable name to logs (as in \"log_path.exe_name.pid\").")
 COMMON_FLAG(
+    const char *, log_suffix, nullptr,
+    "String to append to log file name, e.g. \".txt\".")
+COMMON_FLAG(
     bool, log_to_syslog, SANITIZER_ANDROID || SANITIZER_MAC,
     "Write all sanitizer output to syslog in addition to other means of "
     "logging.")