[sanitizers] introduce a common run-time option dedup_token_length to help with report deduplication, off by default for now. See https://github.com/google/sanitizers/issues/684

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@271085 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc b/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
index f66fa79f1..59ca927fa 100644
--- a/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
@@ -25,6 +25,8 @@ void StackTrace::Print() const {
     return;
   }
   InternalScopedString frame_desc(GetPageSizeCached() * 2);
+  InternalScopedString dedup_token(GetPageSizeCached());
+  int dedup_frames = common_flags()->dedup_token_length;
   uptr frame_num = 0;
   for (uptr i = 0; i < size && trace[i]; i++) {
     // PCs in stack traces are actually the return addresses, that is,
@@ -38,11 +40,18 @@ void StackTrace::Print() const {
                   cur->info, common_flags()->symbolize_vs_style,
                   common_flags()->strip_path_prefix);
       Printf("%s\n", frame_desc.data());
+      if (dedup_frames-- > 0) {
+        if (dedup_token.length())
+          dedup_token.append("--");
+        dedup_token.append(cur->info.function);
+      }
     }
     frames->ClearAll();
   }
   // Always print a trailing empty line after stack trace.
   Printf("\n");
+  if (dedup_token.length())
+    Printf("DEDUP_TOKEN: %s\n", dedup_token.data());
 }
 
 void BufferedStackTrace::Unwind(u32 max_depth, uptr pc, uptr bp, void *context,