Add CMake option to enable the debugging of floating point exceptions

CMakeLists.txt

@@ -64,6 +64,7 @@ OPTION(WANT_VST		"Include VST support" ON)
 OPTION(WANT_VST_NOWINE	"Include partial VST support (without wine)" OFF)
 OPTION(WANT_WINMM	"Include WinMM MIDI support" OFF)
 OPTION(WANT_QT5		"Build with Qt5" OFF)
+OPTION(WANT_DEBUG_FPE	"Debug floating point exceptions" OFF)
 
 
 IF(LMMS_BUILD_APPLE)
@@ -420,6 +421,17 @@ IF(LMMS_BUILD_WIN32)
 	SET(STATUS_VST "OK")
 ENDIF(LMMS_BUILD_WIN32)
 
+IF(WANT_DEBUG_FPE)
+	IF(LMMS_BUILD_LINUX)
+		SET(LMMS_DEBUG_FPE TRUE)
+		SET (STATUS_DEBUG_FPE "Enabled")
+	ELSE()
+		SET (STATUS_DEBUG_FPE "Wanted but disabled due to unsupported platform")
+	ENDIF()
+ELSE()
+	SET (STATUS_DEBUG_FPE "Disabled")
+ENDIF(WANT_DEBUG_FPE)
+
 
 # check for libsamplerate
 PKG_CHECK_MODULES(SAMPLERATE REQUIRED samplerate>=0.1.8)
@@ -599,6 +611,12 @@ MESSAGE(
 "* GIG player                  : ${STATUS_GIG}\n"
 )
 
+MESSAGE(
+"Developer options\n"
+"-----------------------------------------\n"
+"* Debug FP exceptions         : ${STATUS_DEBUG_FPE}\n"
+)
+
 MESSAGE(
 "\n"
 "-----------------------------------------------------------------\n"

src/core/main.cpp

@@ -71,6 +71,33 @@
 #include "Song.h"
 #include "SetupDialog.h"
 
+#ifdef LMMS_DEBUG_FPE
+#include <fenv.h> // For feenableexcept
+#include <execinfo.h> // For backtrace and backtrace_symbols_fd
+#include <unistd.h> // For STDERR_FILENO
+#include <csignal> // To register the signal handler
+#endif
+
+
+#ifdef LMMS_DEBUG_FPE
+void signalHandler( int signum ) {
+
+	// Get a back trace
+	void *array[10];
+	size_t size;
+
+	// get void*'s for all entries on the stack
+	size = backtrace(array, 10);
+
+	backtrace_symbols_fd(array, size, STDERR_FILENO);
+
+	// cleanup and close up stuff here
+	// terminate program
+
+	exit(signum);
+}
+#endif
+
 static inline QString baseName( const QString & file )
 {
 	return QFileInfo( file ).absolutePath() + "/" +
@@ -195,6 +222,18 @@ void fileCheck( QString &file )
 
 int main( int argc, char * * argv )
 {
+#ifdef LMMS_DEBUG_FPE
+	// Enable exceptions for certain floating point results
+	feenableexcept( FE_INVALID   |
+			FE_DIVBYZERO |
+			FE_OVERFLOW  |
+			FE_UNDERFLOW);
+
+	// Install the trap handler
+	// register signal SIGFPE and signal handler
+	signal(SIGFPE, signalHandler);
+#endif
+
 	// initialize memory managers
 	MemoryManager::init();
 	NotePlayHandleManager::init();

src/lmmsconfig.h.in

@@ -21,6 +21,8 @@
 #cmakedefine LMMS_HAVE_STK
 #cmakedefine LMMS_HAVE_VST
 
+#cmakedefine LMMS_DEBUG_FPE
+
 #cmakedefine LMMS_HAVE_STDINT_H
 #cmakedefine LMMS_HAVE_STDLIB_H
 #cmakedefine LMMS_HAVE_PTHREAD_H