Merge pull request #69570 from al45tair/eng/PR-117470489

[Linux] Disable fatalError() backtraces when the runtime backtracer is active.

Author: al45tair

include/swift/Runtime/Backtrace.h

@@ -135,6 +135,10 @@ struct BacktraceSettings {
 
 SWIFT_RUNTIME_STDLIB_INTERNAL BacktraceSettings _swift_backtraceSettings;
 
+inline bool _swift_backtrace_isEnabled() {
+  return _swift_backtraceSettings.enabled == OnOffTty::On;
+}
+
 SWIFT_RUNTIME_STDLIB_SPI
 bool _swift_backtrace_isThunkFunction(const char *mangledName);
 

stdlib/public/runtime/CMakeLists.txt

@@ -151,6 +151,7 @@ add_swift_target_library(swiftRuntime OBJECT_LIBRARY
   ${swift_runtime_threading_sources}
   C_COMPILE_FLAGS
     ${swift_runtime_library_compile_flags}
+    ${swift_enable_backtracing}
   LINK_FLAGS ${swift_runtime_linker_flags}
   SWIFT_COMPILE_FLAGS ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
   INSTALL_IN_COMPONENT never_install)

stdlib/public/runtime/Errors.cpp

@@ -34,6 +34,7 @@
 
 #include "ImageInspection.h"
 #include "swift/Demangling/Demangle.h"
+#include "swift/Runtime/Backtrace.h"
 #include "swift/Runtime/Debug.h"
 #include "swift/Runtime/Portability.h"
 #include "swift/Runtime/Win32.h"
@@ -353,7 +354,13 @@ void swift::swift_reportError(uint32_t flags,
                               const char *message) {
 #if defined(__APPLE__) && NDEBUG
   flags &= ~FatalErrorFlags::ReportBacktrace;
+#elif SWIFT_ENABLE_BACKTRACING
+  // Disable fatalError backtraces if the backtracer is enabled
+  if (runtime::backtrace::_swift_backtrace_isEnabled()) {
+    flags &= ~FatalErrorFlags::ReportBacktrace;
+  }
 #endif
+
   reportNow(flags, message);
   reportOnCrash(flags, message);
 }
@@ -388,9 +395,9 @@ swift::warningv(uint32_t flags, const char *format, va_list args)
 #pragma GCC diagnostic ignored "-Wuninitialized"
   swift_vasprintf(&log, format, args);
 #pragma GCC diagnostic pop
-  
+
   reportNow(flags, log);
-  
+
   free(log);
 }
 

test/Backtracing/FatalError.swift

@@ -37,6 +37,8 @@ struct FatalError {
   }
 }
 
+// CHECK-NOT: Current stack trace:
+
 // CHECK: *** Program crashed: {{Illegal instruction|System trap}} at 0x{{[0-9a-f]+}} ***
 
 // CHECK: Thread 0 {{(".*" )?}}crashed:

test/Runtime/backtrace.swift

@@ -1,6 +1,6 @@
 // RUN: %empty-directory(%t)
 // RUN: %target-build-swift %s -o %t/a.out
-// RUN: %{python} %S/../Inputs/not.py "%target-run %t/a.out" 2>&1 | %{python} %utils/backtrace-check
+// RUN: env SWIFT_BACKTRACE=enable=no %{python} %S/../Inputs/not.py "%target-run %t/a.out" 2>&1 | %{python} %utils/backtrace-check
 
 // NOTE: not.py is used above instead of "not --crash" because %target-run
 // doesn't pass through the crash, and `not` may not be available when running