Merge pull request #1496 from secondlife/nat/catch-test-blown-stack

Attempt to diagnose stack overflow in test programs. Also, improve build.yaml logic.

10 files changed, 246 insertions, 180 deletions

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 903d54210e..d5b4fab380 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -21,13 +21,19 @@ jobs:
     runs-on: ubuntu-latest
     outputs:
       release_run: ${{ steps.setvar.outputs.release_run }}
+      branch:   ${{ steps.which-branch.outputs.branch }}
+      relnotes: ${{ steps.which-branch.outputs.relnotes }}
     env:
       # Build with a tag like "Second_Life#abcdef0" to generate a release page
       # (used for builds we are planning to deploy).
+      # Even though inputs.release_run is specified with type boolean, which
+      # correctly presents a checkbox, its *value* is a GH workflow string
+      # 'true' or 'false'. If you simply test github.event.inputs.release_run,
+      # it always evaluates as true because it's a non-empty string either way.
       # When you want to use a string variable as a workflow YAML boolean, it's
       # important to ensure it's the empty string when false. If you omit || '',
-      # its value when false is "false", which is interpreted as true.
-      RELEASE_RUN: ${{ (github.event.inputs.release_run || github.ref_type == 'tag' && startsWith(github.ref_name, 'Second_Life')) && 'Y' || '' }}
+      # its value when false is "false", which (again) is interpreted as true.
+      RELEASE_RUN: ${{ (github.event.inputs.release_run != 'false' || (github.ref_type == 'tag' && startsWith(github.ref_name, 'Second_Life'))) && 'Y' || '' }}
     steps:
       - name: Set Variable
         id: setvar
@@ -35,6 +41,12 @@ jobs:
         run: |
           echo "release_run=$RELEASE_RUN" >> "$GITHUB_OUTPUT"
 
+      - name: Determine source branch
+        id: which-branch
+        uses: secondlife/viewer-build-util/which-branch@v2
+        with:
+          token: ${{ github.token }}
+
   build:
     needs: setvar
     strategy:
@@ -56,8 +68,6 @@ jobs:
     outputs:
       viewer_channel: ${{ steps.build.outputs.viewer_channel }}
       viewer_version: ${{ steps.build.outputs.viewer_version }}
-      viewer_branch:  ${{ steps.which-branch.outputs.branch }}
-      relnotes:       ${{ steps.which-branch.outputs.relnotes }}
       imagename: ${{ steps.build.outputs.imagename }}
     env:
       AUTOBUILD_ADDRSIZE: 64
@@ -151,19 +161,12 @@ jobs:
         if: env.BUILD && runner.os == 'Windows'
         run: choco install nsis-unicode
 
-      - name: Determine source branch
-        id: which-branch
-        if: env.BUILD
-        uses: secondlife/viewer-build-util/which-branch@v2
-        with:
-          token: ${{ github.token }}
-
       - name: Build
         id: build
         if: env.BUILD
         shell: bash
         env:
-          AUTOBUILD_VCS_BRANCH: ${{ steps.which-branch.outputs.branch }}
+          AUTOBUILD_VCS_BRANCH: ${{ needs.setvar.outputs.branch }}
           RUNNER_OS: ${{ runner.os }}
         run: |
           # set up things the viewer's build.sh script expects
@@ -426,7 +429,11 @@ jobs:
   release:
     needs: [setvar, build, sign-and-package-windows, sign-and-package-mac]
     runs-on: ubuntu-latest
-    if: needs.setvar.outputs.release_run
+    # action-gh-release requires a tag (presumably for automatic generation of
+    # release notes). Possible TODO: if we arrive here but do not have a
+    # suitable tag for github.sha, create one? If we do that, of course remove
+    # this == 'tag' condition.
+    if: needs.setvar.outputs.release_run && github.ref_type == 'tag'
     steps:
       - uses: actions/download-artifact@v4
         with:
@@ -460,7 +467,7 @@ jobs:
             Build ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
             ${{ needs.build.outputs.viewer_channel }}
             ${{ needs.build.outputs.viewer_version }}
-            ${{ needs.build.outputs.relnotes }}
+            ${{ needs.setvar.outputs.relnotes }}
           prerelease: true
           generate_release_notes: true
           target_commitish: ${{ github.sha }}
diff --git a/indra/llcommon/always_return.h b/indra/llcommon/always_return.h
index a206471da5..b99eb49096 100644
--- a/indra/llcommon/always_return.h
+++ b/indra/llcommon/always_return.h
@@ -79,6 +79,22 @@ namespace LL
         DESIRED mDefault;
     };
 
+    // specialize for AlwaysReturn<void>
+    template <>
+    struct AlwaysReturn<void>
+    {
+    public:
+        AlwaysReturn() {}
+
+        // callable returns a type not convertible to DESIRED, return default
+        template <typename CALLABLE, typename... ARGS>
+        void operator()(CALLABLE&& callable, ARGS&&... args)
+        {
+            // discard whatever callable(args) returns
+            std::forward<CALLABLE>(callable)(std::forward<ARGS>(args)...);
+        }
+    };
+
     /**
      * always_return<T>(some_function, some_args...) calls
      * some_function(some_args...). It is guaranteed to return a value of type
diff --git a/indra/llcommon/llcoros.cpp b/indra/llcommon/llcoros.cpp
index aa8eca7d90..7512bac88d 100644
--- a/indra/llcommon/llcoros.cpp
+++ b/indra/llcommon/llcoros.cpp
@@ -123,7 +123,7 @@ LLCoros::LLCoros():
     // Previously we used
     // boost::context::guarded_stack_allocator::default_stacksize();
     // empirically this is insufficient.
-    mStackSize(1024*1024),
+    mStackSize(512*1024),
     // mCurrent does NOT own the current CoroData instance -- it simply
     // points to it. So initialize it with a no-op deleter.
     mCurrent{ [](CoroData*){} }
@@ -155,7 +155,7 @@ void LLCoros::cleanupSingleton()
         // don't use llcoro::suspend() because that module depends
         // on this one
         // This will yield current(main) thread and will let active
-        // corutines run once
+        // coroutines run once
         boost::this_fiber::yield();
     }
     printActiveCoroutines("after pumping");
@@ -286,55 +286,6 @@ std::string LLCoros::launch(const std::string& prefix, const callable_t& callabl
     return name;
 }
 
-namespace
-{
-
-#if LL_WINDOWS
-
-static const U32 STATUS_MSC_EXCEPTION = 0xE06D7363; // compiler specific
-
-U32 exception_filter(U32 code, struct _EXCEPTION_POINTERS *exception_infop)
-{
-    if (code == STATUS_MSC_EXCEPTION)
-    {
-        // C++ exception, go on
-        return EXCEPTION_CONTINUE_SEARCH;
-    }
-    else
-    {
-        // handle it
-        return EXCEPTION_EXECUTE_HANDLER;
-    }
-}
-
-void sehandle(const LLCoros::callable_t& callable)
-{
-    __try
-    {
-        callable();
-    }
-    __except (exception_filter(GetExceptionCode(), GetExceptionInformation()))
-    {
-        // convert to C++ styled exception
-        // Note: it might be better to use _se_set_translator
-        // if you want exception to inherit full callstack
-        char integer_string[512];
-        sprintf(integer_string, "SEH, code: %lu\n", GetExceptionCode());
-        throw std::exception(integer_string);
-    }
-}
-
-#else  // ! LL_WINDOWS
-
-inline void sehandle(const LLCoros::callable_t& callable)
-{
-    callable();
-}
-
-#endif // ! LL_WINDOWS
-
-} // anonymous namespace
-
 // Top-level wrapper around caller's coroutine callable.
 // Normally we like to pass strings and such by const reference -- but in this
 // case, we WANT to copy both the name and the callable to our local stack!
@@ -348,7 +299,7 @@ void LLCoros::toplevel(std::string name, callable_t callable)
     // run the code the caller actually wants in the coroutine
     try
     {
-        sehandle(callable);
+        LL::seh::catcher(callable);
     }
     catch (const Stop& exc)
     {
diff --git a/indra/llcommon/llexception.cpp b/indra/llcommon/llexception.cpp
index c0154a569f..107fdc2b2d 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>
@@ -94,25 +98,47 @@ 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)
+void LL::seh::fill_stacktrace(std::string& stacktrace, U32 code)
 {
-    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;
+    // Sadly, despite its diagnostic importance, trying to capture a
+    // stacktrace when the stack is already blown only terminates us faster.
+    if (code == STATUS_STACK_FULL)
+    {
+        stacktrace = "(stack overflow, no traceback)";
+    }
+    else
+    {
+        stacktrace = to_string(boost::stacktrace::stacktrace());
+    }
+}
 
+U32 LL::seh::common_filter(U32 code, struct _EXCEPTION_POINTERS*)
+{
     if (code == STATUS_MSC_EXCEPTION)
     {
-        // C++ exception, go on
+        // C++ exception, don't stop at this handler
         return EXCEPTION_CONTINUE_SEARCH;
     }
     else
     {
-        // handle it
+        // This is a non-C++ exception, e.g. hardware check.
+        // Pass control into the handler block.
         return EXCEPTION_EXECUTE_HANDLER;
     }
 }
 
+void LL::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
diff --git a/indra/llcommon/llexception.h b/indra/llcommon/llexception.h
index 68e609444e..f58a553eb3 100644
--- a/indra/llcommon/llexception.h
+++ b/indra/llcommon/llexception.h
@@ -12,6 +12,7 @@
 #if ! defined(LL_LLEXCEPTION_H)
 #define LL_LLEXCEPTION_H
 
+#include "always_return.h"
 #include <stdexcept>
 #include <boost/exception/exception.hpp>
 #include <boost/throw_exception.hpp>
@@ -102,14 +103,115 @@ void crash_on_unhandled_exception_(const char*, int, const char*, const std::str
      log_unhandled_exception_(__FILE__, __LINE__, BOOST_CURRENT_FUNCTION, CONTEXT)
 void log_unhandled_exception_(const char*, int, const char*, const std::string&);
 
+/*****************************************************************************
+*   Structured Exception Handling
+*****************************************************************************/
+// this is used in platform-generic code -- define outside #if LL_WINDOWS
+struct Windows_SEH_exception: public LLException
+{
+    Windows_SEH_exception(const std::string& what): LLException(what) {}
+};
+
+namespace LL
+{
+namespace seh
+{
+
+#if LL_WINDOWS //-------------------------------------------------------------
+
+void fill_stacktrace(std::string& stacktrace, U32 code);
+
+// wrapper around caller's U32 filter(U32 code, struct _EXCEPTION_POINTERS*)
+// filter function: capture a stacktrace, if possible, before forwarding the
+// call to the caller's filter() function
+template <typename FILTER>
+U32 filter_(std::string& stacktrace, FILTER&& filter,
+            U32 code, struct _EXCEPTION_POINTERS* exptrs)
+{
+    // By the time the handler gets control, the stack has been unwound,
+    // so report the stack trace now at filter() time.
+    fill_stacktrace(stacktrace, code);
+    return std::forward<FILTER>(filter)(code, exptrs);
+}
+
+template <typename TRYCODE, typename FILTER, typename HANDLER>
+auto catcher_inner(std::string& stacktrace,
+                   TRYCODE&& trycode, FILTER&& filter, HANDLER&& handler)
+{
+    __try
+    {
+        return std::forward<TRYCODE>(trycode)();
+    }
+    __except (filter_(stacktrace,
+                      std::forward<FILTER>(filter),
+                      GetExceptionCode(), GetExceptionInformation()))
+    {
+        return always_return<decltype(trycode())>(
+            std::forward<HANDLER>(handler), GetExceptionCode(), stacktrace);
+    }
+}
+
+// triadic variant specifies try(), filter(U32, struct _EXCEPTION_POINTERS*),
+// handler(U32, const std::string& stacktrace)
+// stacktrace may or may not be available
+template <typename TRYCODE, typename FILTER, typename HANDLER>
+auto catcher(TRYCODE&& trycode, FILTER&& filter, HANDLER&& handler)
+{
+    // Construct and destroy this stacktrace string in the outer function
+    // because we can't do either in the function with __try/__except.
+    std::string stacktrace;
+    return catcher_inner(stacktrace,
+                         std::forward<TRYCODE>(trycode),
+                         std::forward<FILTER>(filter),
+                         std::forward<HANDLER>(handler));
+}
 
-#if LL_WINDOWS
+// common_filter() handles the typical case in which we want our handler
+// clause to handle only Structured Exceptions rather than explicitly-thrown
+// C++ exceptions
+U32 common_filter(U32 code, struct _EXCEPTION_POINTERS*);
+
+// dyadic variant specifies try(), handler(U32, stacktrace), assumes common_filter()
+template <typename TRYCODE, typename HANDLER>
+auto catcher(TRYCODE&& trycode, HANDLER&& handler)
+{
+    return catcher(std::forward<TRYCODE>(trycode),
+                   common_filter,
+                   std::forward<HANDLER>(handler));
+}
+
+// monadic variant specifies try(), assumes default filter and handler
+template <typename TRYCODE>
+auto catcher(TRYCODE&& trycode)
+{
+    return catcher(std::forward<TRYCODE>(trycode), rethrow);
+}
+
+[[noreturn]] void rethrow(U32 code, const std::string& stacktrace);
+
+#else  // not LL_WINDOWS -----------------------------------------------------
+
+template <typename TRYCODE, typename FILTER, typename HANDLER>
+auto catcher(TRYCODE&& trycode, FILTER&&, HANDLER&&)
+{
+    return std::forward<TRYCODE>(trycode)();
+}
+
+template <typename TRYCODE, typename HANDLER>
+auto catcher(TRYCODE&& trycode, HANDLER&&)
+{
+    return std::forward<TRYCODE>(trycode)();
+}
+
+template <typename TRYCODE>
+auto catcher(TRYCODE&& trycode)
+{
+    return std::forward<TRYCODE>(trycode)();
+}
 
-// SEH exception filtering for use in __try __except
-// Separates C++ exceptions from C SEH exceptions
-// Todo: might be good idea to do some kind of seh_to_msc_wrapper(function, ARGS&&);
-U32 msc_exception_filter(U32 code, struct _EXCEPTION_POINTERS *exception_infop);
+#endif // not LL_WINDOWS -----------------------------------------------------
 
-#endif //LL_WINDOWS
+} // namespace LL::seh
+} // namespace LL
 
 #endif /* ! defined(LL_LLEXCEPTION_H) */
diff --git a/indra/llcommon/tests/llleap_test.cpp b/indra/llcommon/tests/llleap_test.cpp
index fa48bcdefd..3fb25b4cef 100644
--- a/indra/llcommon/tests/llleap_test.cpp
+++ b/indra/llcommon/tests/llleap_test.cpp
@@ -35,7 +35,7 @@
 // causes Windows abdominal pain such that it later fails code-signing in some
 // mysterious way. Entirely suppressing these LLLeap tests pushes the failure
 // rate MUCH lower. Can we re-enable them with a smaller data size on Windows?
-const size_t BUFFERED_LENGTH =  100*1024;
+const size_t BUFFERED_LENGTH = 1023*1024;
 
 #else // not Windows
 const size_t BUFFERED_LENGTH = 1023*1024; // try wrangling just under a megabyte of data
diff --git a/indra/llwindow/llwindowwin32.cpp b/indra/llwindow/llwindowwin32.cpp
index d6b93b93d9..12cd5320b8 100644
--- a/indra/llwindow/llwindowwin32.cpp
+++ b/indra/llwindow/llwindowwin32.cpp
@@ -163,18 +163,7 @@ HGLRC SafeCreateContext(HDC &hdc)
 
 GLuint SafeChoosePixelFormat(HDC &hdc, const PIXELFORMATDESCRIPTOR *ppfd)
 {
-    __try
-    {
-        return ChoosePixelFormat(hdc, ppfd);
-    }
-    __except (EXCEPTION_EXECUTE_HANDLER)
-    {
-        // convert to C++ styled exception
-        // C exception don't allow classes, so it's a regular char array
-        char integer_string[32];
-        sprintf(integer_string, "SEH, code: %lu\n", GetExceptionCode());
-        throw std::exception(integer_string);
-    }
+    return LL::seh::catcher([hdc, ppfd]{ return ChoosePixelFormat(hdc, ppfd); });
 }
 
 //static
diff --git a/indra/newview/llappviewerwin32.cpp b/indra/newview/llappviewerwin32.cpp
index 4c90a82fcb..a13e4de308 100644
--- a/indra/newview/llappviewerwin32.cpp
+++ b/indra/newview/llappviewerwin32.cpp
@@ -400,17 +400,10 @@ void ll_nvapi_init(NvDRSSessionHandle hSession)
     }
 }
 
-//#define DEBUGGING_SEH_FILTER 1
-#if DEBUGGING_SEH_FILTER
-#   define WINMAIN DebuggingWinMain
-#else
-#   define WINMAIN wWinMain
-#endif
-
-int APIENTRY WINMAIN(HINSTANCE hInstance,
-                     HINSTANCE hPrevInstance,
-                     PWSTR     pCmdLine,
-                     int       nCmdShow)
+int APIENTRY wWinMain(HINSTANCE hInstance,
+                      HINSTANCE hPrevInstance,
+                      PWSTR     pCmdLine,
+                      int       nCmdShow)
 {
     // Call Tracy first thing to have it allocate memory
     // https://github.com/wolfpld/tracy/issues/196
@@ -559,27 +552,6 @@ int APIENTRY WINMAIN(HINSTANCE hInstance,
     return 0;
 }
 
-#if DEBUGGING_SEH_FILTER
-// The compiler doesn't like it when you use __try/__except blocks
-// in a method that uses object destructors. Go figure.
-// This winmain just calls the real winmain inside __try.
-// The __except calls our exception filter function. For debugging purposes.
-int APIENTRY wWinMain(HINSTANCE hInstance,
-                     HINSTANCE hPrevInstance,
-                     PWSTR     lpCmdLine,
-                     int       nCmdShow)
-{
-    __try
-    {
-        WINMAIN(hInstance, hPrevInstance, lpCmdLine, nCmdShow);
-    }
-    __except( viewer_windows_exception_handler( GetExceptionInformation() ) )
-    {
-        _tprintf( _T("Exception handled.\n") );
-    }
-}
-#endif
-
 void LLAppViewerWin32::disableWinErrorReporting()
 {
     std::string executable_name = gDirUtilp->getExecutableFilename();
diff --git a/indra/newview/llfeaturemanager.cpp b/indra/newview/llfeaturemanager.cpp
index 99139e6528..765599bb82 100644
--- a/indra/newview/llfeaturemanager.cpp
+++ b/indra/newview/llfeaturemanager.cpp
@@ -40,6 +40,7 @@
 
 #include "llappviewer.h"
 #include "llbufferstream.h"
+#include "llexception.h"
 #include "llnotificationsutil.h"
 #include "llviewercontrol.h"
 #include "llworld.h"
@@ -377,33 +378,6 @@ bool LLFeatureManager::parseFeatureTable(std::string filename)
 
 F32 gpu_benchmark();
 
-#if LL_WINDOWS
-
-F32 logExceptionBenchmark()
-{
-    // FIXME: gpu_benchmark uses many C++ classes on the stack to control state.
-    //  SEH exceptions with our current exception handling options do not call
-    //  destructors for these classes, resulting in an undefined state should
-    //  this handler be invoked.
-    F32 gbps = -1;
-    __try
-    {
-        gbps = gpu_benchmark();
-    }
-    __except (msc_exception_filter(GetExceptionCode(), GetExceptionInformation()))
-    {
-        // HACK - ensure that profiling is disabled
-        LLGLSLShader::finishProfile(false);
-
-        // convert to C++ styled exception
-        char integer_string[32];
-        sprintf(integer_string, "SEH, code: %lu\n", GetExceptionCode());
-        throw std::exception(integer_string);
-    }
-    return gbps;
-}
-#endif
-
 bool LLFeatureManager::loadGPUClass()
 {
     if (!gSavedSettings.getBOOL("SkipBenchmark"))
@@ -413,14 +387,12 @@ bool LLFeatureManager::loadGPUClass()
         F32 gbps;
         try
         {
-#if LL_WINDOWS
-            gbps = logExceptionBenchmark();
-#else
-            gbps = gpu_benchmark();
-#endif
+            gbps = LL::seh::catcher(gpu_benchmark);
         }
         catch (const std::exception& e)
         {
+            // HACK - ensure that profiling is disabled
+            LLGLSLShader::finishProfile(false);
             gbps = -1.f;
             LL_WARNS("RenderInit") << "GPU benchmark failed: " << e.what() << LL_ENDL;
         }
diff --git a/indra/test/test.cpp b/indra/test/test.cpp
index cbd1077306..cc2c130072 100644
--- a/indra/test/test.cpp
+++ b/indra/test/test.cpp
@@ -36,6 +36,7 @@
 
 #include "linden_common.h"
 #include "llerrorcontrol.h"
+#include "llexception.h"
 #include "lltut.h"
 #include "chained_callback.h"
 #include "stringize.h"
@@ -63,11 +64,6 @@
 #pragma warning (pop)
 #endif
 
-#include <boost/scoped_ptr.hpp>
-#include <boost/shared_ptr.hpp>
-#include <boost/make_shared.hpp>
-#include <boost/foreach.hpp>
-
 #include <fstream>
 
 void wouldHaveCrashed(const std::string& message);
@@ -176,10 +172,6 @@ public:
     LLTestCallback(bool verbose_mode, std::ostream *stream,
                    std::shared_ptr<LLReplayLog> replayer) :
         mVerboseMode(verbose_mode),
-        mTotalTests(0),
-        mPassedTests(0),
-        mFailedTests(0),
-        mSkippedTests(0),
         // By default, capture a shared_ptr to std::cout, with a no-op "deleter"
         // so that destroying the shared_ptr makes no attempt to delete std::cout.
         mStream(std::shared_ptr<std::ostream>(&std::cout, [](std::ostream*){})),
@@ -215,6 +207,8 @@ public:
     virtual void group_started(const std::string& name) {
         LL_INFOS("TestRunner")<<"Unit test group_started name=" << name << LL_ENDL;
         *mStream << "Unit test group_started name=" << name << std::endl;
+        mGroup = name;
+        mGroupTests = 0;
         super::group_started(name);
     }
 
@@ -227,6 +221,7 @@ public:
     virtual void test_completed(const tut::test_result& tr)
     {
         ++mTotalTests;
+        ++mGroupTests;
 
         // If this test failed, dump requested log messages BEFORE stating the
         // test result.
@@ -314,12 +309,15 @@ public:
         super::run_completed();
     }
 
+    std::string mGroup;
+    int mGroupTests{ 0 };
+
 protected:
-    bool mVerboseMode;
-    int mTotalTests;
-    int mPassedTests;
-    int mFailedTests;
-    int mSkippedTests;
+    bool mVerboseMode{ false };
+    int mTotalTests{ 0 };
+    int mPassedTests{ 0 };
+    int mFailedTests{ 0 };
+    int mSkippedTests{ 0 };
     std::shared_ptr<std::ostream> mStream;
     std::shared_ptr<LLReplayLog> mReplayer;
 };
@@ -647,14 +645,47 @@ int main(int argc, char **argv)
     // a chained_callback subclass must be linked with previous
     mycallback->link();
 
-    if(test_group.empty())
-    {
-        tut::runner.get().run_tests();
-    }
-    else
-    {
-        tut::runner.get().run_tests(test_group);
-    }
+    LL::seh::catcher(
+        // __try
+        [test_group]
+        {
+            if(test_group.empty())
+            {
+                tut::runner.get().run_tests();
+            }
+            else
+            {
+                tut::runner.get().run_tests(test_group);
+            }
+        },
+        // __except
+        [mycallback](U32 code, const std::string& /*stacktrace*/)
+        {
+            static std::map<U32, const char*> codes = {
+                { 0xC0000005, "Access Violation" },
+                { 0xC00000FD, "Stack Overflow" },
+                // ... continue filling in as desired
+            };
+
+            auto found{ codes.find(code) };
+            const char* name = ((found == codes.end())? "unknown" : found->second);
+            auto msg{ stringize("test threw ", std::hex, code, " (", name, ")") };
+
+            // Instead of bombing the whole test run, report this as a test
+            // failure. Arguably, catching structured exceptions should be
+            // hacked into TUT itself.
+            mycallback->test_completed(tut::test_result(
+                mycallback->mGroup,
+                mycallback->mGroupTests+1, // test within group
+                "unknown",                 // test name
+                tut::test_result::ex,      // result: exception
+                // we don't have to throw this exception subclass to use it to
+                // populate the test_result struct
+                Windows_SEH_exception(msg)));
+            // we've left the TUT framework -- finish up by hand
+            mycallback->group_completed(mycallback->mGroup);
+            mycallback->run_completed();
+        });
 
     bool success = (mycallback->getFailedTests() == 0);