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| author | Lexi Winter <lexi@le-fay.org> | 2025-06-29 19:25:29 +0100 |
|---|---|---|
| committer | Lexi Winter <lexi@le-fay.org> | 2025-06-29 19:25:29 +0100 |
| commit | bc524d70253a4ab2fe40c3ca3e5666e267c0a4d1 (patch) | |
| tree | 1e629e7b46b1d9972a973bc93fd100bcebd395be /src/catch2/internal/catch_fatal_condition_handler.cpp | |
| download | nihil-vendor/catch2.tar.gz nihil-vendor/catch2.tar.bz2 | |
import catch2 3.8.1vendor/catch2/3.8.1vendor/catch2
Diffstat (limited to 'src/catch2/internal/catch_fatal_condition_handler.cpp')
| -rw-r--r-- | src/catch2/internal/catch_fatal_condition_handler.cpp | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/src/catch2/internal/catch_fatal_condition_handler.cpp b/src/catch2/internal/catch_fatal_condition_handler.cpp new file mode 100644 index 0000000..9ef5b21 --- /dev/null +++ b/src/catch2/internal/catch_fatal_condition_handler.cpp @@ -0,0 +1,244 @@ + +// Copyright Catch2 Authors +// Distributed under the Boost Software License, Version 1.0. +// (See accompanying file LICENSE.txt or copy at +// https://www.boost.org/LICENSE_1_0.txt) + +// SPDX-License-Identifier: BSL-1.0 + +/** \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 <catch2/internal/catch_fatal_condition_handler.hpp> + +#include <catch2/internal/catch_compiler_capabilities.hpp> +#include <catch2/internal/catch_context.hpp> +#include <catch2/internal/catch_enforce.hpp> +#include <catch2/interfaces/catch_interfaces_capture.hpp> +#include <catch2/internal/catch_windows_h_proxy.hpp> +#include <catch2/internal/catch_stdstreams.hpp> + +#include <algorithm> + +#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. + void FatalConditionHandler::engage_platform() {} + void FatalConditionHandler::disengage_platform() noexcept {} + 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 { + //! Signals fatal error message to the run context + void reportFatal( char const * const message ) { + Catch::getCurrentContext().getResultCapture()->handleFatalErrorCondition( message ); + } + + //! Minimal size Catch2 needs for its own fatal error handling. + //! Picked empirically, 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. + // Windows can easily distinguish between SO and SigSegV, + // but SigInt, SigTerm, etc are handled differently. + static SignalDefs signalDefs[] = { + { EXCEPTION_ILLEGAL_INSTRUCTION, "SIGILL - Illegal instruction signal" }, + { EXCEPTION_STACK_OVERFLOW, "SIGSEGV - Stack overflow" }, + { EXCEPTION_ACCESS_VIOLATION, "SIGSEGV - Segmentation violation signal" }, + { EXCEPTION_INT_DIVIDE_BY_ZERO, "Divide by zero error" }, + }; + + static LONG CALLBACK topLevelExceptionFilter(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; + } + + // Since we do not support multiple instantiations, we put these + // into global variables and rely on cleaning them up in outlined + // constructors/destructors + static LPTOP_LEVEL_EXCEPTION_FILTER previousTopLevelExceptionFilter = nullptr; + + + // For MSVC, we reserve part of the stack memory for handling + // memory overflow structured exception. + FatalConditionHandler::FatalConditionHandler() { + ULONG guaranteeSize = static_cast<ULONG>(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."; + } + } + + // 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 a the top level exception filter. + previousTopLevelExceptionFilter = SetUnhandledExceptionFilter(topLevelExceptionFilter); + } + + void FatalConditionHandler::disengage_platform() noexcept { + if (SetUnhandledExceptionFilter(previousTopLevelExceptionFilter) != topLevelExceptionFilter) { + Catch::cerr() + << "Unexpected SEH unhandled exception filter on disengage." + << " The filter was restored, but might be rolled back unexpectedly."; + } + previousTopLevelExceptionFilter = nullptr; + } + +} // end namespace Catch + +#endif // CATCH_CONFIG_WINDOWS_SEH + +#if defined( CATCH_CONFIG_POSIX_SIGNALS ) + +#include <signal.h> + +namespace Catch { + + struct SignalDefs { + int id; + const char* name; + }; + + 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" } + }; + +// 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 + + 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() noexcept { + // 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 = "<unknown signal>"; + for (auto const& def : signalDefs) { + if (sig == def.id) { + name = def.name; + break; + } + } + // 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() { + assert(!altStackMem && "Cannot initialize POSIX signal handler when one already exists"); + if (altStackSize == 0) { + altStackSize = std::max(static_cast<size_t>(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 = altStackSize; + 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]); + } + } + +#if defined(__GNUC__) +# pragma GCC diagnostic pop +#endif + + + void FatalConditionHandler::disengage_platform() noexcept { + restorePreviousSignalHandlers(); + } + +} // end namespace Catch + +#endif // CATCH_CONFIG_POSIX_SIGNALS |
