Promote seh_catcher() et al. to llexception.{h,cpp} for general use.

1 files changed, 42 insertions, 8 deletions

diff --git a/indra/llcommon/llexception.cpp b/indra/llcommon/llexception.cpp
index c0154a569f..74b33f1e3b 100644
--- a/indra/llcommon/llexception.cpp
+++ b/indra/llcommon/llexception.cpp
@@ -15,7 +15,12 @@
 #include "llexception.h"
 // STL headers
 // std headers
+#include <iomanip>
+#include <sstream>
 #include <typeinfo>
+#if LL_WINDOWS
+#include <excpt.h>
+#endif // LL_WINDOWS
 // external library headers
 #include <boost/exception/diagnostic_information.hpp>
 #include <boost/exception/error_info.hpp>
@@ -29,7 +34,6 @@
 // On Windows, header-only implementation causes macro collisions -- use
 // prebuilt library
 #define BOOST_STACKTRACE_LINK
-#include <excpt.h>
 #endif // LL_WINDOWS
 
 #include <boost/stacktrace.hpp>
@@ -94,15 +98,34 @@ void annotate_exception_(boost::exception& exc)
 
 // For windows SEH exception handling we sometimes need a filter that will
 // separate C++ exceptions from C SEH exceptions
-static const U32 STATUS_MSC_EXCEPTION = 0xE06D7363; // compiler specific
+static constexpr U32 STATUS_MSC_EXCEPTION = 0xE06D7363; // compiler specific
+static constexpr U32 STATUS_STACK_FULL    = 0xC00000FD;
 
-U32 msc_exception_filter(U32 code, struct _EXCEPTION_POINTERS *exception_infop)
+U32 ll_seh_filter(
+    std::string& stacktrace,
+    std::function<U32(U32, struct _EXCEPTION_POINTERS*)> filter,
+    U32 code,
+    struct _EXCEPTION_POINTERS* exception_infop)
 {
-    const auto stack = to_string(boost::stacktrace::stacktrace());
-    LL_WARNS() << "SEH Exception handled (that probably shouldn't be): Code " << code
-        << "\n Stack trace: \n"
-        << stack << LL_ENDL;
+    // By the time the handler gets control, the stack has been unwound,
+    // so report the stack trace now at filter() time.
+    // Even though stack overflow is a problem we would very much like to
+    // diagnose, calling another function when the stack is already blown only
+    // terminates us faster.
+    if (code == STATUS_STACK_FULL)
+    {
+        stacktrace = "(stack overflow, no traceback)";
+    }
+    else
+    {
+        stacktrace = boost::stacktrace::stacktrace().to_string();
+    }
+    
+    return filter(code, exception_infop);
+}
 
+U32 seh_filter(U32 code, struct _EXCEPTION_POINTERS*)
+{
     if (code == STATUS_MSC_EXCEPTION)
     {
         // C++ exception, go on
@@ -110,9 +133,20 @@ U32 msc_exception_filter(U32 code, struct _EXCEPTION_POINTERS *exception_infop)
     }
     else
     {
-        // handle it
+        // This is a non-C++ exception, e.g. hardware check.
         return EXCEPTION_EXECUTE_HANDLER;
     }
 }
 
+void seh_rethrow(U32 code, const std::string& stacktrace)
+{
+    std::ostringstream out;
+    out << "Windows exception 0x" << std::hex << code;
+    if (! stacktrace.empty())
+    {
+        out << '\n' << stacktrace;
+    }
+    LLTHROW(Windows_SEH_exception(out.str()));
+}
+
 #endif //LL_WINDOWS