Small cleanup of fatal condition handler

src/catch2/internal/catch_fatal_condition_handler.cpp

@@ -0,0 +1,161 @@
+/*
+ *  Created by Phil on 21/08/2014
+ *  Copyright 2014 Two Blue Cubes Ltd. All rights reserved.
+ *
+ *  Distributed under the Boost Software License, Version 1.0. (See accompanying
+ *  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+ *
+ */
+
+#include <catch2/internal/catch_fatal_condition_handler.hpp>
+
+#include <catch2/internal/catch_context.hpp>
+#include <catch2/interfaces/catch_interfaces_capture.hpp>
+
+#if defined(__GNUC__)
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wmissing-field-initializers"
+#endif
+
+#if defined( CATCH_CONFIG_WINDOWS_SEH ) || defined( CATCH_CONFIG_POSIX_SIGNALS )
+
+namespace {
+    // Report the error condition
+    void reportFatal( char const * const message ) {
+        Catch::getCurrentContext().getResultCapture()->handleFatalErrorCondition( message );
+    }
+}
+
+#endif // signals/SEH handling
+
+#if defined( CATCH_CONFIG_WINDOWS_SEH )
+
+namespace Catch {
+    struct SignalDefs { DWORD id; const char* name; };
+
+    // There is no 1-1 mapping between signals and windows exceptions.
+    // Windows can easily distinguish between SO and SigSegV,
+    // but SigInt, SigTerm, etc are handled differently.
+    static SignalDefs signalDefs[] = {
+        { static_cast<DWORD>(EXCEPTION_ILLEGAL_INSTRUCTION),  "SIGILL - Illegal instruction signal" },
+        { static_cast<DWORD>(EXCEPTION_STACK_OVERFLOW), "SIGSEGV - Stack overflow" },
+        { static_cast<DWORD>(EXCEPTION_ACCESS_VIOLATION), "SIGSEGV - Segmentation violation signal" },
+        { static_cast<DWORD>(EXCEPTION_INT_DIVIDE_BY_ZERO), "Divide by zero error" },
+    };
+
+    LONG CALLBACK FatalConditionHandler::handleVectoredException(PEXCEPTION_POINTERS ExceptionInfo) {
+        for (auto const& def : signalDefs) {
+            if (ExceptionInfo->ExceptionRecord->ExceptionCode == def.id) {
+                reportFatal(def.name);
+            }
+        }
+        // If its not an exception we care about, pass it along.
+        // This stops us from eating debugger breaks etc.
+        return EXCEPTION_CONTINUE_SEARCH;
+    }
+
+    FatalConditionHandler::FatalConditionHandler() {
+        isSet = true;
+        // 32k seems enough for Catch to handle stack overflow,
+        // but the value was found experimentally, so there is no strong guarantee
+        guaranteeSize = 32 * 1024;
+        exceptionHandlerHandle = nullptr;
+        // Register as first handler in current chain
+        exceptionHandlerHandle = AddVectoredExceptionHandler(1, handleVectoredException);
+        // Pass in guarantee size to be filled
+        SetThreadStackGuarantee(&guaranteeSize);
+    }
+
+    void FatalConditionHandler::reset() {
+        if (isSet) {
+            RemoveVectoredExceptionHandler(exceptionHandlerHandle);
+            SetThreadStackGuarantee(&guaranteeSize);
+            exceptionHandlerHandle = nullptr;
+            isSet = false;
+        }
+    }
+
+bool FatalConditionHandler::isSet = false;
+ULONG FatalConditionHandler::guaranteeSize = 0;
+PVOID FatalConditionHandler::exceptionHandlerHandle = nullptr;
+
+
+} // namespace Catch
+
+#elif defined( CATCH_CONFIG_POSIX_SIGNALS )
+
+namespace Catch {
+
+    struct SignalDefs {
+        int id;
+        const char* name;
+    };
+
+    // 32kb for the alternate stack seems to be sufficient. However, this value
+    // is experimentally determined, so that's not guaranteed.
+    static constexpr std::size_t sigStackSize = 32768 >= MINSIGSTKSZ ? 32768 : MINSIGSTKSZ;
+
+    static SignalDefs signalDefs[] = {
+        { SIGINT,  "SIGINT - Terminal interrupt signal" },
+        { SIGILL,  "SIGILL - Illegal instruction signal" },
+        { SIGFPE,  "SIGFPE - Floating point error signal" },
+        { SIGSEGV, "SIGSEGV - Segmentation violation signal" },
+        { SIGTERM, "SIGTERM - Termination request signal" },
+        { SIGABRT, "SIGABRT - Abort (abnormal termination) signal" }
+    };
+
+
+    void FatalConditionHandler::handleSignal( int sig ) {
+        char const * name = "<unknown signal>";
+        for (auto const& def : signalDefs) {
+            if (sig == def.id) {
+                name = def.name;
+                break;
+            }
+        }
+        reset();
+        reportFatal(name);
+        raise( sig );
+    }
+
+    FatalConditionHandler::FatalConditionHandler() {
+        isSet = true;
+        stack_t sigStack;
+        sigStack.ss_sp = altStackMem;
+        sigStack.ss_size = sigStackSize;
+        sigStack.ss_flags = 0;
+        sigaltstack(&sigStack, &oldSigStack);
+        struct sigaction sa = { };
+
+        sa.sa_handler = handleSignal;
+        sa.sa_flags = SA_ONSTACK;
+        for (std::size_t i = 0; i < sizeof(signalDefs)/sizeof(SignalDefs); ++i) {
+            sigaction(signalDefs[i].id, &sa, &oldSigActions[i]);
+        }
+    }
+
+    void FatalConditionHandler::reset() {
+        if( isSet ) {
+            // Set signals back to previous values -- hopefully nobody overwrote them in the meantime
+            for( std::size_t i = 0; i < sizeof(signalDefs)/sizeof(SignalDefs); ++i ) {
+                sigaction(signalDefs[i].id, &oldSigActions[i], nullptr);
+            }
+            // Return the old stack
+            sigaltstack(&oldSigStack, nullptr);
+            isSet = false;
+        }
+    }
+
+    bool FatalConditionHandler::isSet = false;
+    struct sigaction FatalConditionHandler::oldSigActions[sizeof(signalDefs)/sizeof(SignalDefs)] = {};
+    stack_t FatalConditionHandler::oldSigStack = {};
+    char FatalConditionHandler::altStackMem[sigStackSize] = {};
+
+
+} // namespace Catch
+
+#endif // signals/SEH handling
+
+#if defined(__GNUC__)
+#    pragma GCC diagnostic pop
+#endif