Properly print the backtrace and generate a core dump on both Windows/Unix

code/sys/CMakeLists.txt

@@ -44,6 +44,7 @@ target_link_libraries(syslib INTERFACE qcommon)
 if(WIN32)
 	target_link_libraries(syslib INTERFACE wsock32 ws2_32)
 	target_link_libraries(syslib INTERFACE winmm)
+	target_link_libraries(syslib INTERFACE dbghelp)
 elseif(UNIX)
 	find_package(Threads)
 	target_link_libraries(syslib INTERFACE ${CMAKE_DL_LIBS} ${CMAKE_THREAD_LIBS_INIT})

code/sys/new/sys_unix_new.c

@@ -49,14 +49,18 @@ Sys_PrintBackTrace
 ==================
 */
 void Sys_PrintBackTrace() {
-    void* backtrace_arr[64];
+    void* backtrace_arr[128];
+    char** backtrace_symbols_arr;
     size_t backtrace_size;
+    size_t i;
 
-    printf("----\nBacktrace:\n");
+    // Fetch the backtrace starting from the current function
-    // get void*'s for all entries on the stack
+    backtrace_size = backtrace(backtrace_arr, ARRAY_LEN(backtrace_arr));
-    backtrace_size = backtrace(backtrace_arr, sizeof(backtrace_arr) / sizeof(backtrace_arr[0]));
+    backtrace_symbols_arr = backtrace_symbols(backtrace_arr, ARRAY_LEN(backtrace_arr));
-    backtrace_symbols_fd(backtrace_arr, backtrace_size, STDERR_FILENO);
+
-    printf("----\n");
+    for (i = 0; i < backtrace_size; i++) {
+        fprintf(stderr, "=> %s\n", backtrace_symbols_arr[i]);
+    }
 }
 
 /*

code/sys/new/sys_win32_new.c

@@ -23,6 +23,8 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include "../sys_local.h"
 
 #include <Windows.h>
+#include <dbghelp.h>
+
 #ifdef _MSC_VER
 #  ifdef _DEBUG_MEM
 #    include <crtdbg.h>
@@ -51,6 +53,34 @@ Sys_PrintBackTrace
 ==============
 */
 void Sys_PrintBackTrace() {
+    void* backtrace[128];
+    SYMBOL_INFO* symbol;
+    HANDLE hProcess;
+    unsigned int i;
+    unsigned short frames;
+
+    hProcess = GetCurrentProcess();
+
+    // Initialize the symbol handler
+    SymInitialize(hProcess, NULL, TRUE);
+
+    // Gather the list of frames
+    frames = CaptureStackBackTrace(0, ARRAY_LEN(backtrace), backtrace, NULL);
+    // Allocate a symbol structure to get the name of each symbol
+    // with a maximum of 127 characters per symbol
+    symbol = (SYMBOL_INFO*)malloc(sizeof(SYMBOL_INFO) + 128 * sizeof(char));
+    symbol->MaxNameLen = 127;
+    symbol->SizeOfStruct = sizeof(SYMBOL_INFO);
+
+    for (i = 0; i < frames; i++)
+    {
+        // Try to translate the address to a symbol with a name
+        SymFromAddr(hProcess, (DWORD64)(backtrace[i]), 0, symbol);
+
+        fprintf(stderr, "=> %s[0x%p]\n", symbol->Name, (void*)symbol->Address);
+    }
+
+    free(symbol);
 }
 
 /*

code/sys/sys_main.c

@@ -715,7 +715,7 @@ char *Sys_ParseProtocolUri( const char *uri )
 Sys_SigHandler
 =================
 */
-void Sys_SigHandler( int signal )
+void Sys_SigHandler( int signum )
 {
 	static qboolean signalcaught = qfalse;
 
@@ -727,7 +727,13 @@ void Sys_SigHandler( int signal )
 	else
 	{
 		signalcaught = qtrue;
+
+        printf("----\nBacktrace:\n");
         Sys_PrintBackTrace();
+        printf("----\n");
+		// Call the default signal handler to generate a core dump
+		SIG_DFL(signum);
+
 		VM_Forced_Unload_Start();
 #ifndef DEDICATED
 		CL_Shutdown(va("Received signal %d", signal), qtrue, qtrue);