[rtsan] Add support for ReportErrorSummary (#116424)

Adding support for the extra SUMMARY line that is output by most
compilers. This also adds the ability for end-users to specify their own
handlers for reporting these errors (see the test).

compiler-rt/lib/rtsan/rtsan.cpp

@@ -62,8 +62,12 @@ static void OnViolation(const BufferedStackTrace &stack,
   if (UNLIKELY(is_stack_novel)) {
     IncrementUniqueErrorCount();
 
-    PrintDiagnostics(info);
-    stack.Print();
+    {
+      ScopedErrorReportLock l;
+      PrintDiagnostics(info);
+      stack.Print();
+      PrintErrorSummary(info, stack);
+    }
 
     handle.inc_use_count_unsafe();
   }

compiler-rt/lib/rtsan/rtsan_diagnostics.cpp

@@ -39,20 +39,22 @@ public:
 };
 } // namespace
 
+static const char *GetErrorTypeStr(const DiagnosticsInfo &info) {
+  switch (info.type) {
+  case DiagnosticsInfoType::InterceptedCall:
+    return "unsafe-library-call";
+  case DiagnosticsInfoType::BlockingCall:
+    return "blocking-call";
+  }
+  CHECK(false);
+  return "(unknown error)";
+}
+
 static void PrintError(const Decorator &decorator,
                        const DiagnosticsInfo &info) {
-  const auto ErrorTypeStr = [&info]() -> const char * {
-    switch (info.type) {
-    case DiagnosticsInfoType::InterceptedCall:
-      return "unsafe-library-call";
-    case DiagnosticsInfoType::BlockingCall:
-      return "blocking-call";
-    }
-    return "(unknown error)";
-  };
 
   Printf("%s", decorator.Error());
-  Report("ERROR: RealtimeSanitizer: %s\n", ErrorTypeStr());
+  Report("ERROR: RealtimeSanitizer: %s\n", GetErrorTypeStr(info));
 }
 
 static void PrintReason(const Decorator &decorator,
@@ -78,10 +80,16 @@ static void PrintReason(const Decorator &decorator,
 }
 
 void __rtsan::PrintDiagnostics(const DiagnosticsInfo &info) {
-  ScopedErrorReportLock l;
+  ScopedErrorReportLock::CheckLocked();
 
   Decorator d;
   PrintError(d, info);
   PrintReason(d, info);
   Printf("%s", d.Default());
 }
+
+void __rtsan::PrintErrorSummary(const DiagnosticsInfo &info,
+                                const BufferedStackTrace &stack) {
+  ScopedErrorReportLock::CheckLocked();
+  ReportErrorSummary(GetErrorTypeStr(info), &stack);
+}

compiler-rt/lib/rtsan/rtsan_diagnostics.h

@@ -30,4 +30,6 @@ struct DiagnosticsInfo {
 };
 
 void PrintDiagnostics(const DiagnosticsInfo &info);
+void PrintErrorSummary(const DiagnosticsInfo &info,
+                       const __sanitizer::BufferedStackTrace &stack);
 } // namespace __rtsan

compiler-rt/test/rtsan/report_error_summary.cpp

@@ -0,0 +1,32 @@
+// RUN: %clangxx -fsanitize=realtime %s -o %t
+// RUN: %env_rtsan_opts="halt_on_error=false" %run %t 2>&1 | FileCheck %s
+
+// RUN: %clangxx -DTEST_CUSTOM_HANDLER=1 -fsanitize=realtime %s -o %t
+// RUN: not %run %t 2>&1 | FileCheck %s --check-prefixes=CHECK-CUSTOM-HANDLER
+
+// UNSUPPORTED: ios
+
+// Intent: Make sure we support ReporErrorSummary, including custom handlers
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef TEST_CUSTOM_HANDLER
+extern "C" void __sanitizer_report_error_summary(const char *error_summary) {
+  fprintf(stderr, "%s %s\n", "In custom handler! ", error_summary);
+}
+#endif
+
+int blocking_call() [[clang::blocking]] { return 0; }
+
+int main() [[clang::nonblocking]] {
+  void *ptr = malloc(2);
+  blocking_call();
+
+  printf("ptr: %p\n", ptr); // ensure we don't optimize out the malloc
+}
+
+// CHECK: SUMMARY: RealtimeSanitizer: unsafe-library-call
+// CHECK: SUMMARY: RealtimeSanitizer: blocking-call
+
+// CHECK-CUSTOM-HANDLER: In custom handler! SUMMARY: RealtimeSanitizer: unsafe-library-call