Add support for -fno-exceptions (or equivalent)

This means

* Adding new configuration toggle `CATCH_CONFIG_DISABLE_EXCEPTIONS`
and a best-guess configuration auto-checking for it.
* Adding new set of internal macros, `CATCH_TRY`, `CATCH_CATCH_ALL`
and `CATCH_CATCH_ANON` that can be used in place of regular `try`,
`catch(...)` and `catch(T const&)` respectively, while disappearing
when `CATCH_CONFIG_DISABLE_EXCEPTIONS` is enabled.
* Replacing all uses of `throw` with calls to `Catch::throw_exception`
customization point.
* Providing a default implementation for the above customization point
when `CATCH_CONFIG_DISABLE_EXCEPTIONS` is set.
* Letting users override this implementation with their own.
* Some minor changes and ifdefs all around to support the above

include/internal/catch_assertionhandler.cpp

@@ -81,8 +81,13 @@ namespace Catch {
             // (To go back to the test and change execution, jump over the throw, next)
             CATCH_BREAK_INTO_DEBUGGER();
         }
-        if( m_reaction.shouldThrow )
+        if (m_reaction.shouldThrow) {
+#if !defined(CATCH_CONFIG_DISABLE_EXCEPTIONS)
             throw Catch::TestFailureException();
+#else
+            CATCH_ERROR( "Test failure requires aborting test!" );
+#endif
+        }
     }
     void AssertionHandler::setCompleted() {
         m_completed = true;

include/internal/catch_capture.hpp

@@ -21,7 +21,7 @@
   #define CATCH_INTERNAL_STRINGIFY(...) "Disabled by CATCH_CONFIG_DISABLE_STRINGIFICATION"
 #endif
 
-#if defined(CATCH_CONFIG_FAST_COMPILE)
+#if defined(CATCH_CONFIG_FAST_COMPILE) || defined(CATCH_CONFIG_DISABLE_EXCEPTIONS)
 
 ///////////////////////////////////////////////////////////////////////////////
 // Another way to speed-up compilation is to omit local try-catch for REQUIRE*

include/internal/catch_compiler_capabilities.h

@@ -14,6 +14,7 @@
 // CATCH_CONFIG_COUNTER : is the __COUNTER__ macro supported?
 // CATCH_CONFIG_WINDOWS_SEH : is Windows SEH supported?
 // CATCH_CONFIG_POSIX_SIGNALS : are POSIX signals supported?
+// CATCH_CONFIG_DISABLE_EXCEPTIONS : Are exceptions enabled?
 // ****************
 // Note to maintainers: if new toggles are added please document them
 // in configuration.md, too
@@ -131,7 +132,12 @@
 #endif // _MSC_VER
 
 ////////////////////////////////////////////////////////////////////////////////
+// Check if we are compiled with -fno-exceptions or equivalent
+#if defined(__EXCEPTIONS) || defined(__cpp_exceptions) || defined(_CPPUNWIND)
+#  define CATCH_INTERNAL_CONFIG_EXCEPTIONS_ENABLED
+#endif
 
+////////////////////////////////////////////////////////////////////////////////
 // DJGPP
 #ifdef __DJGPP__
 #  define CATCH_INTERNAL_CONFIG_NO_WCHAR
@@ -179,6 +185,10 @@
 #  define CATCH_CONFIG_NEW_CAPTURE
 #endif
 
+#if !defined(CATCH_INTERNAL_CONFIG_EXCEPTIONS_ENABLED) && !defined(CATCH_CONFIG_DISABLE_EXCEPTIONS)
+#  define CATCH_CONFIG_DISABLE_EXCEPTIONS
+#endif
+
 #if !defined(CATCH_INTERNAL_SUPPRESS_PARENTHESES_WARNINGS)
 #   define CATCH_INTERNAL_SUPPRESS_PARENTHESES_WARNINGS
 #   define CATCH_INTERNAL_UNSUPPRESS_PARENTHESES_WARNINGS
@@ -192,6 +202,16 @@
 #   define CATCH_INTERNAL_UNSUPPRESS_UNUSED_WARNINGS
 #endif
 
+#if defined(CATCH_CONFIG_DISABLE_EXCEPTIONS)
+#define CATCH_TRY if ((true))
+#define CATCH_CATCH_ALL if ((false))
+#define CATCH_CATCH_ANON(type) if ((false))
+#else
+#define CATCH_TRY try
+#define CATCH_CATCH_ALL catch (...)
+#define CATCH_CATCH_ANON(type) catch (type)
+#endif
+
 
 #endif // TWOBLUECUBES_CATCH_COMPILER_CAPABILITIES_HPP_INCLUDED
 

include/internal/catch_enforce.cpp

@@ -0,0 +1,19 @@
+/*
+ *  Created by Martin on 03/09/2018.
+ *
+ *  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 "catch_enforce.h"
+
+namespace Catch {
+#if defined(CATCH_CONFIG_DISABLE_EXCEPTIONS) && !defined(CATCH_CONFIG_DISABLE_EXCEPTIONS_CUSTOM_HANDLER)
+    [[noreturn]]
+    void throw_exception(std::exception const& e) {
+        Catch::cerr() << "Catch will terminate because it needed to throw an exception.\n"
+                      << "The message was: " << e.what() << '\n';
+        std::terminate();
+    }
+#endif
+} // namespace Catch;

include/internal/catch_enforce.h

@@ -8,19 +8,35 @@
 #define TWOBLUECUBES_CATCH_ENFORCE_H_INCLUDED
 
 #include "catch_common.h"
+#include "catch_compiler_capabilities.h"
 #include "catch_stream.h"
 
+
 #include <stdexcept>
 
+namespace Catch {
+#if !defined(CATCH_CONFIG_DISABLE_EXCEPTIONS)
+    template <typename Ex>
+    [[noreturn]]
+    void throw_exception(Ex const& e) {
+        throw e;
+    }
+#else // ^^ Exceptions are enabled //  Exceptions are disabled vv
+    [[noreturn]]
+    void throw_exception(std::exception const& e);
+#endif
+} // namespace Catch;
+
 #define CATCH_PREPARE_EXCEPTION( type, msg ) \
     type( ( Catch::ReusableStringStream() << msg ).str() )
 #define CATCH_INTERNAL_ERROR( msg ) \
-    throw CATCH_PREPARE_EXCEPTION( std::logic_error, CATCH_INTERNAL_LINEINFO << ": Internal Catch error: " << msg);
+    Catch::throw_exception(CATCH_PREPARE_EXCEPTION( std::logic_error, CATCH_INTERNAL_LINEINFO << ": Internal Catch error: " << msg))
 #define CATCH_ERROR( msg ) \
-    throw CATCH_PREPARE_EXCEPTION( std::domain_error, msg )
+    Catch::throw_exception(CATCH_PREPARE_EXCEPTION( std::domain_error, msg ))
 #define CATCH_RUNTIME_ERROR( msg ) \
-    throw CATCH_PREPARE_EXCEPTION( std::runtime_error, msg )
+    Catch::throw_exception(CATCH_PREPARE_EXCEPTION( std::runtime_error, msg ))
 #define CATCH_ENFORCE( condition, msg ) \
     do{ if( !(condition) ) CATCH_ERROR( msg ); } while(false)
 
+
 #endif // TWOBLUECUBES_CATCH_ENFORCE_H_INCLUDED

include/internal/catch_exception_translator_registry.cpp

@@ -6,8 +6,10 @@
  *  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  */
 
-#include "catch_assertionhandler.h"
 #include "catch_exception_translator_registry.h"
+#include "catch_assertionhandler.h"
+#include "catch_compiler_capabilities.h"
+#include "catch_enforce.h"
 
 #ifdef __OBJC__
 #import "Foundation/Foundation.h"
@@ -22,6 +24,7 @@ namespace Catch {
         m_translators.push_back( std::unique_ptr<const IExceptionTranslator>( translator ) );
     }
 
+#if !defined(CATCH_CONFIG_DISABLE_EXCEPTIONS)
     std::string ExceptionTranslatorRegistry::translateActiveException() const {
         try {
 #ifdef __OBJC__
@@ -64,6 +67,13 @@ namespace Catch {
         }
     }
 
+#else // ^^ Exceptions are enabled // Exceptions are disabled vv
+    std::string ExceptionTranslatorRegistry::translateActiveException() const {
+        CATCH_INTERNAL_ERROR("Attempted to translate active exception under CATCH_CONFIG_DISABLE_EXCEPTIONS!");
+    }
+#endif
+
+
     std::string ExceptionTranslatorRegistry::tryTranslators() const {
         if( m_translators.empty() )
             std::rethrow_exception(std::current_exception());

include/internal/catch_run_context.cpp

@@ -1,4 +1,5 @@
 #include "catch_run_context.h"
+#include "catch_compiler_capabilities.h"
 #include "catch_context.h"
 #include "catch_enforce.h"
 #include "catch_random_number_generator.h"
@@ -327,7 +328,7 @@ namespace Catch {
         seedRng(*m_config);
 
         Timer timer;
-        try {
+        CATCH_TRY {
             if (m_reporter->getPreferences().shouldRedirectStdOut) {
 #if !defined(CATCH_CONFIG_EXPERIMENTAL_REDIRECT)
                 RedirectedStdOut redirectedStdOut;
@@ -347,9 +348,9 @@ namespace Catch {
                 invokeActiveTestCase();
             }
             duration = timer.getElapsedSeconds();
-        } catch (TestFailureException&) {
+        } CATCH_CATCH_ANON (TestFailureException&) {
             // This just means the test was aborted due to failure
-        } catch (...) {
+        } CATCH_CATCH_ALL {
             // Under CATCH_CONFIG_FAST_COMPILE, unexpected exceptions under REQUIRE assertions
             // are reported without translation at the point of origin.
             if( m_shouldReportUnexpected ) {

include/internal/catch_session.cpp

@@ -119,10 +119,12 @@ namespace Catch {
     Session::Session() {
         static bool alreadyInstantiated = false;
         if( alreadyInstantiated ) {
-            try         { CATCH_INTERNAL_ERROR( "Only one instance of Catch::Session can ever be used" ); }
-            catch(...)  { getMutableRegistryHub().registerStartupException(); }
+            CATCH_TRY { CATCH_INTERNAL_ERROR( "Only one instance of Catch::Session can ever be used" ); }
+            CATCH_CATCH_ALL { getMutableRegistryHub().registerStartupException(); }
         }
 
+        // There cannot be exceptions at startup in no-exception mode.
+#if !defined(CATCH_CONFIG_DISABLE_EXCEPTIONS)
         const auto& exceptions = getRegistryHub().getStartupExceptionRegistry().getExceptions();
         if ( !exceptions.empty() ) {
             m_startupExceptions = true;
@@ -137,6 +139,7 @@ namespace Catch {
                 }
             }
         }
+#endif
 
         alreadyInstantiated = true;
         m_cli = makeCommandLineParser( m_configData );
@@ -251,11 +254,11 @@ namespace Catch {
         if( m_startupExceptions )
             return 1;
 
-        if( m_configData.showHelp || m_configData.libIdentify )
+        if (m_configData.showHelp || m_configData.libIdentify) {
             return 0;
+        }
 
-        try
-        {
+        CATCH_TRY {
             config(); // Force config to be constructed
 
             seedRng( *m_config );
@@ -273,10 +276,12 @@ namespace Catch {
             // of 256 tests has failed
             return (std::min) (MaxExitCode, (std::max) (totals.error, static_cast<int>(totals.assertions.failed)));
         }
+#if !defined(CATCH_CONFIG_DISABLE_EXCEPTIONS)
         catch( std::exception& ex ) {
             Catch::cerr() << ex.what() << std::endl;
             return MaxExitCode;
         }
+#endif
     }
 
 } // end namespace Catch

include/internal/catch_startup_exception_registry.cpp

@@ -7,13 +7,13 @@
  */
 
 #include "catch_startup_exception_registry.h"
+#include "catch_compiler_capabilities.h"
 
 namespace Catch {
-    void StartupExceptionRegistry::add( std::exception_ptr const& exception ) noexcept {
-        try {
+void StartupExceptionRegistry::add( std::exception_ptr const& exception ) noexcept {
+        CATCH_TRY {
             m_exceptions.push_back(exception);
-        }
-        catch(...) {
+        } CATCH_CATCH_ALL {
             // If we run out of memory during start-up there's really not a lot more we can do about it
             std::terminate();
         }

include/internal/catch_tag_alias_autoregistrar.cpp

@@ -1,12 +1,13 @@
 #include "catch_tag_alias_autoregistrar.h"
+#include "catch_compiler_capabilities.h"
 #include "catch_interfaces_registry_hub.h"
 
 namespace Catch {
-    
+
     RegistrarForTagAliases::RegistrarForTagAliases(char const* alias, char const* tag, SourceLineInfo const& lineInfo) {
-        try {
+        CATCH_TRY {
             getMutableRegistryHub().registerTagAlias(alias, tag, lineInfo);
-        } catch (...) {
+        } CATCH_CATCH_ALL {
             // Do not throw when constructing global objects, instead register the exception to be processed later
             getMutableRegistryHub().registerStartupException();
         }

include/internal/catch_test_registry.cpp

@@ -6,6 +6,7 @@
  */
 
 #include "catch_test_registry.h"
+#include "catch_compiler_capabilities.h"
 #include "catch_test_case_registry_impl.h"
 #include "catch_interfaces_registry_hub.h"
 
@@ -18,7 +19,7 @@ namespace Catch {
     NameAndTags::NameAndTags( StringRef const& name_ , StringRef const& tags_ ) noexcept : name( name_ ), tags( tags_ ) {}
 
     AutoReg::AutoReg( ITestInvoker* invoker, SourceLineInfo const& lineInfo, StringRef const& classOrMethod, NameAndTags const& nameAndTags ) noexcept {
-        try {
+        CATCH_TRY {
             getMutableRegistryHub()
                     .registerTest(
                         makeTestCase(
@@ -26,7 +27,7 @@ namespace Catch {
                             extractClassName( classOrMethod ),
                             nameAndTags,
                             lineInfo));
-        } catch (...) {
+        } CATCH_CATCH_ALL {
             // Do not throw when constructing global objects, instead register the exception to be processed later
             getMutableRegistryHub().registerStartupException();
         }

projects/CMakeLists.txt

@@ -173,6 +173,7 @@ set(IMPL_SOURCES
         ${HEADER_DIR}/internal/catch_debug_console.cpp
         ${HEADER_DIR}/internal/catch_debugger.cpp
         ${HEADER_DIR}/internal/catch_decomposer.cpp
+        ${HEADER_DIR}/internal/catch_enforce.cpp
         ${HEADER_DIR}/internal/catch_errno_guard.cpp
         ${HEADER_DIR}/internal/catch_exception_translator_registry.cpp
         ${HEADER_DIR}/internal/catch_fatal_condition.cpp