[UBSan] Clarify the way we disable de-duplication of reports from unrecoverable handlers.

Let unrecoverable handlers be responsbile for killing the
program with Die(), and let functions which print the error
report know if it's going to happen. Re-write the comments to
describe the situation.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@255081 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 16 insertions, 12 deletions

diff --git a/lib/ubsan/ubsan_handlers.cc b/lib/ubsan/ubsan_handlers.cc
index 69bde0dca..b85a5aba8 100644
--- a/lib/ubsan/ubsan_handlers.cc
+++ b/lib/ubsan/ubsan_handlers.cc
@@ -21,17 +21,20 @@
 using namespace __sanitizer;
 using namespace __ubsan;
 
-static bool ignoreReport(SourceLocation SLoc, ReportOptions Opts) {
-  // If source location is already acquired, we don't need to print an error
-  // report for the second time. However, if we're in an unrecoverable handler,
-  // it's possible that location was required by concurrently running thread.
-  // In this case, we should continue the execution to ensure that any of
-  // threads will grab the report mutex and print the report before
-  // crashing the program.
-  return SLoc.isDisabled() && !Opts.DieAfterReport;
+namespace __ubsan {
+bool ignoreReport(SourceLocation SLoc, ReportOptions Opts) {
+  // We are not allowed to skip error report: if we are in unrecoverable
+  // handler, we have to terminate the program right now, and therefore
+  // have to print some diagnostic.
+  //
+  // Even if source location is disabled, it doesn't mean that we have
+  // already report an error to the user: some concurrently running
+  // thread could have acquired it, but not yet printed the report.
+  if (Opts.FromUnrecoverableHandler)
+    return false;
+  return SLoc.isDisabled();
 }
 
-namespace __ubsan {
 const char *TypeCheckKinds[] = {
     "load of", "store to", "reference binding to", "member access within",
     "member call on", "constructor call on", "downcast of", "downcast of",
@@ -116,12 +119,13 @@ static void handleIntegerOverflowImpl(OverflowData *Data, ValueHandle LHS,
     << Value(Data->Type, LHS) << Operator << RHS << Data->Type;
 }
 
-#define UBSAN_OVERFLOW_HANDLER(handler_name, op, abort)                        \
+#define UBSAN_OVERFLOW_HANDLER(handler_name, op, unrecoverable)                \
   void __ubsan::handler_name(OverflowData *Data, ValueHandle LHS,              \
                              ValueHandle RHS) {                                \
-    GET_REPORT_OPTIONS(abort);                                                 \
+    GET_REPORT_OPTIONS(unrecoverable);                                         \
     handleIntegerOverflowImpl(Data, LHS, op, Value(Data->Type, RHS), Opts);    \
-    if (abort) Die();                                                          \
+    if (unrecoverable)                                                         \
+      Die();                                                                   \
   }
 
 UBSAN_OVERFLOW_HANDLER(__ubsan_handle_add_overflow, "+", false)