diff --git a/include/internal/catch_fatal_condition.cpp b/include/internal/catch_fatal_condition.cpp index 1eb6bb87..ac601f67 100644 --- a/include/internal/catch_fatal_condition.cpp +++ b/include/internal/catch_fatal_condition.cpp @@ -7,30 +7,72 @@ * */ +/** \file + * This file provides platform specific implementations of FatalConditionHandler + * + * This means that there is a lot of conditional compilation, and platform + * specific code. Currently, Catch2 supports a dummy handler (if no + * handler is desired), and 2 platform specific handlers: + * * Windows' SEH + * * POSIX signals + * + * Consequently, various pieces of code below are compiled if either of + * the platform specific handlers is enabled, or if none of them are + * enabled. It is assumed that both cannot be enabled at the same time, + * and doing so should cause a compilation error. + * + * If another platform specific handler is added, the compile guards + * below will need to be updated taking these assumptions into account. + */ + #include "catch_fatal_condition.h" #include "catch_context.h" -#include "catch_interfaces_capture.h" +#include "catch_enforce.h" +#include "catch_run_context.h" +#include "catch_windows_h_proxy.h" -#if defined(__GNUC__) -# pragma GCC diagnostic push -# pragma GCC diagnostic ignored "-Wmissing-field-initializers" -#endif +#include + +#if !defined( CATCH_CONFIG_WINDOWS_SEH ) && !defined( CATCH_CONFIG_POSIX_SIGNALS ) + +namespace Catch { + + // If neither SEH nor signal handling is required, the handler impls + // do not have to do anything, and can be empty. + FatalConditionHandler::engage_platform() {} + FatalConditionHandler::disengage_platform() {} + FatalConditionHandler::FatalConditionHandler() = default; + FatalConditionHandler::~FatalConditionHandler() = default; + +} // end namespace Catch + +#endif // !CATCH_CONFIG_WINDOWS_SEH && !CATCH_CONFIG_POSIX_SIGNALS + +#if defined( CATCH_CONFIG_WINDOWS_SEH ) && defined( CATCH_CONFIG_POSIX_SIGNALS ) +#error "Inconsistent configuration: Windows' SEH handling and POSIX signals cannot be enabled at the same time" +#endif // CATCH_CONFIG_WINDOWS_SEH && CATCH_CONFIG_POSIX_SIGNALS #if defined( CATCH_CONFIG_WINDOWS_SEH ) || defined( CATCH_CONFIG_POSIX_SIGNALS ) namespace { - // Report the error condition + //! Signals fatal error message to the run context void reportFatal( char const * const message ) { Catch::getCurrentContext().getResultCapture()->handleFatalErrorCondition( message ); } -} -#endif // signals/SEH handling + //! Minimal size Catch2 needs for its own fatal error handling. + //! Picked anecdotally, so it might not be sufficient on all + //! platforms, and for all configurations. + constexpr std::size_t minStackSizeForErrors = 32 * 1024; +} // end unnamed namespace + +#endif // CATCH_CONFIG_WINDOWS_SEH || CATCH_CONFIG_POSIX_SIGNALS #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. @@ -43,7 +85,7 @@ namespace Catch { { static_cast(EXCEPTION_INT_DIVIDE_BY_ZERO), "Divide by zero error" }, }; - LONG CALLBACK FatalConditionHandler::handleVectoredException(PEXCEPTION_POINTERS ExceptionInfo) { + static LONG CALLBACK handleVectoredException(PEXCEPTION_POINTERS ExceptionInfo) { for (auto const& def : signalDefs) { if (ExceptionInfo->ExceptionRecord->ExceptionCode == def.id) { reportFatal(def.name); @@ -54,39 +96,52 @@ namespace Catch { 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); - } + // Since we do not support multiple instantiations, we put these + // into global variables and rely on cleaning them up in outlined + // constructors/destructors + static PVOID exceptionHandlerHandle = nullptr; - void FatalConditionHandler::reset() { - if (isSet) { - RemoveVectoredExceptionHandler(exceptionHandlerHandle); - SetThreadStackGuarantee(&guaranteeSize); - exceptionHandlerHandle = nullptr; - isSet = false; + + // For MSVC, we reserve part of the stack memory for handling + // memory overflow structured exception. + FatalConditionHandler::FatalConditionHandler() { + ULONG guaranteeSize = static_cast(minStackSizeForErrors); + if (!SetThreadStackGuarantee(&guaranteeSize)) { + // We do not want to fully error out, because needing + // the stack reserve should be rare enough anyway. + Catch::cerr() + << "Failed to reserve piece of stack." + << " Stack overflows will not be reported successfully."; } } - FatalConditionHandler::~FatalConditionHandler() { - reset(); + // We do not attempt to unset the stack guarantee, because + // Windows does not support lowering the stack size guarantee. + FatalConditionHandler::~FatalConditionHandler() = default; + + + void FatalConditionHandler::engage_platform() { + // Register as first handler in current chain + exceptionHandlerHandle = AddVectoredExceptionHandler(1, handleVectoredException); + if (!exceptionHandlerHandle) { + CATCH_RUNTIME_ERROR("Could not register vectored exception handler"); + } } -bool FatalConditionHandler::isSet = false; -ULONG FatalConditionHandler::guaranteeSize = 0; -PVOID FatalConditionHandler::exceptionHandlerHandle = nullptr; + void FatalConditionHandler::disengage_platform() { + if (!RemoveVectoredExceptionHandler(exceptionHandlerHandle)) { + CATCH_RUNTIME_ERROR("Could not unregister vectored exception handler"); + } + exceptionHandlerHandle = nullptr; + } +} // end namespace Catch -} // namespace Catch +#endif // CATCH_CONFIG_WINDOWS_SEH -#elif defined( CATCH_CONFIG_POSIX_SIGNALS ) +#if defined( CATCH_CONFIG_POSIX_SIGNALS ) + +#include namespace Catch { @@ -94,10 +149,6 @@ namespace Catch { 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" }, @@ -108,8 +159,32 @@ namespace Catch { { SIGABRT, "SIGABRT - Abort (abnormal termination) signal" } }; +// Older GCCs trigger -Wmissing-field-initializers for T foo = {} +// which is zero initialization, but not explicit. We want to avoid +// that. +#if defined(__GNUC__) +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Wmissing-field-initializers" +#endif - void FatalConditionHandler::handleSignal( int sig ) { + static char* altStackMem = nullptr; + static std::size_t altStackSize = 0; + static stack_t oldSigStack{}; + static struct sigaction oldSigActions[sizeof(signalDefs) / sizeof(SignalDefs)]{}; + + static void restorePreviousSignalHandlers() { + // We set signal handlers back to the previous ones. Hopefully + // nobody overwrote them in the meantime, and doesn't expect + // their signal handlers to live past ours given that they + // installed them after ours.. + 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); + } + + static void handleSignal( int sig ) { char const * name = ""; for (auto const& def : signalDefs) { if (sig == def.id) { @@ -117,16 +192,33 @@ namespace Catch { break; } } - reset(); - reportFatal(name); + // We need to restore previous signal handlers and let them do + // their thing, so that the users can have the debugger break + // when a signal is raised, and so on. + restorePreviousSignalHandlers(); + reportFatal( name ); raise( sig ); } FatalConditionHandler::FatalConditionHandler() { - isSet = true; + assert(!altStackMem && "Cannot initialize POSIX signal handler when one already exists"); + if (altStackSize == 0) { + altStackSize = std::max(static_cast(SIGSTKSZ), minStackSizeForErrors); + } + altStackMem = new char[altStackSize](); + } + + FatalConditionHandler::~FatalConditionHandler() { + delete[] altStackMem; + // We signal that another instance can be constructed by zeroing + // out the pointer. + altStackMem = nullptr; + } + + void FatalConditionHandler::engage_platform() { stack_t sigStack; sigStack.ss_sp = altStackMem; - sigStack.ss_size = sigStackSize; + sigStack.ss_size = altStackSize; sigStack.ss_flags = 0; sigaltstack(&sigStack, &oldSigStack); struct sigaction sa = { }; @@ -138,39 +230,15 @@ namespace Catch { } } - - FatalConditionHandler::~FatalConditionHandler() { - reset(); - } - - 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 - -#else - -namespace Catch { - void FatalConditionHandler::reset() {} -} - -#endif // signals/SEH handling - #if defined(__GNUC__) # pragma GCC diagnostic pop #endif + + + void FatalConditionHandler::disengage_platform() { + restorePreviousSignalHandlers(); + } + +} // end namespace Catch + +#endif // CATCH_CONFIG_POSIX_SIGNALS diff --git a/include/internal/catch_fatal_condition.h b/include/internal/catch_fatal_condition.h index a64fa628..6b5f8f91 100644 --- a/include/internal/catch_fatal_condition.h +++ b/include/internal/catch_fatal_condition.h @@ -11,59 +11,60 @@ #include "catch_platform.h" #include "catch_compiler_capabilities.h" -#include "catch_windows_h_proxy.h" - -#if defined( CATCH_CONFIG_WINDOWS_SEH ) +#include namespace Catch { - struct FatalConditionHandler { - - static LONG CALLBACK handleVectoredException(PEXCEPTION_POINTERS ExceptionInfo); - FatalConditionHandler(); - static void reset(); - ~FatalConditionHandler(); - - private: - static bool isSet; - static ULONG guaranteeSize; - static PVOID exceptionHandlerHandle; - }; - -} // namespace Catch - -#elif defined ( CATCH_CONFIG_POSIX_SIGNALS ) - -#include - -namespace Catch { - - struct FatalConditionHandler { - - static bool isSet; - static struct sigaction oldSigActions[]; - static stack_t oldSigStack; - static char altStackMem[]; - - static void handleSignal( int sig ); + /** + * Wrapper for platform-specific fatal error (signals/SEH) handlers + * + * Tries to be cooperative with other handlers, and not step over + * other handlers. This means that unknown structured exceptions + * are passed on, previous signal handlers are called, and so on. + * + * Can only be instantiated once, and assumes that once a signal + * is caught, the binary will end up terminating. Thus, there + */ + class FatalConditionHandler { + bool m_started = false; + // Install/disengage implementation for specific platform. + // Should be if-defed to work on current platform, can assume + // engage-disengage 1:1 pairing. + void engage_platform(); + void disengage_platform(); + public: + // Should also have platform-specific implementations as needed FatalConditionHandler(); ~FatalConditionHandler(); - static void reset(); + + void engage() { + assert(!m_started && "Handler cannot be installed twice."); + m_started = true; + engage_platform(); + } + + void disengage() { + assert(m_started && "Handler cannot be uninstalled without being installed first"); + m_started = false; + disengage_platform(); + } }; -} // namespace Catch - - -#else - -namespace Catch { - struct FatalConditionHandler { - void reset(); + //! Simple RAII guard for (dis)engaging the FatalConditionHandler + class FatalConditionHandlerGuard { + FatalConditionHandler* m_handler; + public: + FatalConditionHandlerGuard(FatalConditionHandler* handler): + m_handler(handler) { + m_handler->engage(); + } + ~FatalConditionHandlerGuard() { + m_handler->disengage(); + } }; -} -#endif +} // end namespace Catch #endif // TWOBLUECUBES_CATCH_FATAL_CONDITION_H_INCLUDED diff --git a/include/internal/catch_run_context.cpp b/include/internal/catch_run_context.cpp index fa1b2f6f..de38e285 100644 --- a/include/internal/catch_run_context.cpp +++ b/include/internal/catch_run_context.cpp @@ -452,9 +452,8 @@ namespace Catch { } void RunContext::invokeActiveTestCase() { - FatalConditionHandler fatalConditionHandler; // Handle signals + FatalConditionHandlerGuard _(&m_fatalConditionhandler); m_activeTestCase->invoke(); - fatalConditionHandler.reset(); } void RunContext::handleUnfinishedSections() { diff --git a/include/internal/catch_run_context.h b/include/internal/catch_run_context.h index 044bdd81..2f3adbda 100644 --- a/include/internal/catch_run_context.h +++ b/include/internal/catch_run_context.h @@ -146,6 +146,7 @@ namespace Catch { std::vector m_unfinishedSections; std::vector m_activeSections; TrackerContext m_trackerContext; + FatalConditionHandler m_fatalConditionhandler; bool m_lastAssertionPassed = false; bool m_shouldReportUnexpected = true; bool m_includeSuccessfulResults;