Add asm-volatile trick

kstenerud · May 23, 2024 · 9f493ba · 9f493ba
1 parent 9337991
commit 9f493ba
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diff --git a/Sources/KSCrashRecording/Monitors/KSCrashMonitor_CPPException.cpp b/Sources/KSCrashRecording/Monitors/KSCrashMonitor_CPPException.cpp
@@ -83,6 +83,7 @@ static void captureStackTrace(void*, std::type_info*, void (*)(void*)) __attribu
     {
         kssc_initSelfThread(&g_stackCursor, 2);
     }
+    __asm__ __volatile__(""); // thwart tail-call optimization
 }
 
 typedef void (*cxa_throw_type)(void*, std::type_info*, void (*)(void*));
@@ -103,6 +104,7 @@ extern "C"
             orig_cxa_throw = (cxa_throw_type) dlsym(RTLD_NEXT, "__cxa_throw");
         }
         orig_cxa_throw(thrown_exception, tinfo, dest);
+        __asm__ __volatile__(""); // thwart tail-call optimization
         __builtin_unreachable();
     }
 }

diff --git a/Sources/KSCrashRecordingCore/KSStackCursor_SelfThread.c b/Sources/KSCrashRecordingCore/KSStackCursor_SelfThread.c
@@ -43,4 +43,5 @@ void kssc_initSelfThread(KSStackCursor *cursor, int skipEntries) __attribute__((
     SelfThreadContext* context = (SelfThreadContext*)cursor->context;
     int backtraceLength = backtrace((void**)context->backtrace, MAX_BACKTRACE_LENGTH);
     kssc_initWithBacktrace(cursor, context->backtrace, backtraceLength, skipEntries + 1);
+    __asm__ __volatile__(""); // thwart tail-call optimization
 }