Color stacktraces printed by the crash handler when in a TTY

This makes them easier to read.

Author: Calinou

platform/linuxbsd/crash_handler_linuxbsd.cpp

@@ -47,6 +47,7 @@
 #include <link.h>
 #include <signal.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 static void handle_crash(int sig) {
 	signal(SIGSEGV, SIG_DFL);
@@ -72,9 +73,13 @@ static void handle_crash(int sig) {
 		OS::get_singleton()->get_main_loop()->notification(MainLoop::NOTIFICATION_CRASH);
 	}
 
-	// Dump the backtrace to stderr with a message to the user
+	// Dump the backtrace to stderr with a message to the user.
 	print_error("\n================================================================");
-	print_error(vformat("%s: Program crashed with signal %d", __FUNCTION__, sig));
+	if (isatty(fileno(stderr))) {
+		print_error(vformat("\x1b[1;91m%s: Program crashed with signal %d.\x1b[0m", __FUNCTION__, sig));
+	} else {
+		print_error(vformat("%s: Program crashed with signal %d.", __FUNCTION__, sig));
+	}
 
 	// Print the engine version just before, so that people are reminded to include the version in backtrace reports.
 	if (String(VERSION_HASH).is_empty()) {
@@ -133,7 +138,13 @@ static void handle_crash(int sig) {
 				}
 			}
 
-			print_error(vformat("[%d] %s (%s)", (int64_t)i, fname, err == OK ? addr2line_results[i] : ""));
+			if (isatty(fileno(stderr))) {
+				// Print colors using ANSI escape codes for easier visual grepping.
+				print_error(vformat("\x1b[94m[%d] \x1b[96m%s \x1b[90m(%s)\x1b[0m", (int64_t)i, fname, err == OK ? addr2line_results[i] : ""));
+			} else {
+				// Not a TTY (could be writing to a file). Don't use ANSI escape codes.
+				print_error(vformat("[%d] %s (%s)", (int64_t)i, fname, err == OK ? addr2line_results[i] : ""));
+			}
 		}
 
 		free(strings);

platform/macos/crash_handler_macos.mm

@@ -49,6 +49,7 @@
 #include <execinfo.h>
 #include <signal.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 #include <mach-o/dyld.h>
 #include <mach-o/getsect.h>
@@ -96,9 +97,13 @@ static void handle_crash(int sig) {
 		OS::get_singleton()->get_main_loop()->notification(MainLoop::NOTIFICATION_CRASH);
 	}
 
-	// Dump the backtrace to stderr with a message to the user
+	// Dump the backtrace to stderr with a message to the user.
 	print_error("\n================================================================");
-	print_error(vformat("%s: Program crashed with signal %d", __FUNCTION__, sig));
+	if (isatty(fileno(stderr))) {
+		print_error(vformat("\x1b[1;91m%s: Program crashed with signal %d.\x1b[0m", __FUNCTION__, sig));
+	} else {
+		print_error(vformat("%s: Program crashed with signal %d.", __FUNCTION__, sig));
+	}
 
 	// Print the engine version just before, so that people are reminded to include the version in backtrace reports.
 	if (String(VERSION_HASH).is_empty()) {
@@ -165,7 +170,13 @@ static void handle_crash(int sig) {
 				}
 			}
 
-			print_error(vformat("[%d] %s", (int64_t)i, output));
+			if (isatty(fileno(stderr))) {
+				// Print colors using ANSI escape codes for easier visual grepping.
+				print_error(vformat("\x1b[94m[%d] \x1b[96m%s\x1b[0m", uint64_t(i), output.utf8().ptr()));
+			} else {
+				// Not a TTY (could be writing to a file). Don't use ANSI escape codes.
+				print_error(vformat("[%d] %s", uint64_t(i), output.utf8().ptr()));
+			}
 		}
 
 		free(strings);

platform/windows/crash_handler_windows_seh.cpp

@@ -139,7 +139,7 @@ DWORD CrashHandlerException(EXCEPTION_POINTERS *ep) {
 	}
 
 	print_error("\n================================================================");
-	print_error(vformat("%s: Program crashed", __FUNCTION__));
+	print_error(vformat("\x1b[1;91m%s: Program crashed.\x1b[0m", __FUNCTION__));
 
 	// Print the engine version just before, so that people are reminded to include the version in backtrace reports.
 	if (String(VERSION_HASH).is_empty()) {
@@ -204,12 +204,12 @@ DWORD CrashHandlerException(EXCEPTION_POINTERS *ep) {
 				std::string fnName = symbol(process, frame.AddrPC.Offset).undecorated_name();
 
 				if (SymGetLineFromAddr64(process, frame.AddrPC.Offset, &offset_from_symbol, &line)) {
-					print_error(vformat("[%d] %s (%s:%d)", n, fnName.c_str(), (char *)line.FileName, (int)line.LineNumber));
+					print_error(vformat("\x1b[94m[%d] \x1b[96m%s \x1b[90m(%s:%d)\x1b[0m", n, fnName.c_str(), line.FileName, uint32_t(line.LineNumber)));
 				} else {
-					print_error(vformat("[%d] %s", n, fnName.c_str()));
+					print_error(vformat("\x1b[94m[%d] \x1b[96m%s\x1b[0m", n, fnName.c_str()));
 				}
 			} else {
-				print_error(vformat("[%d] ???", n));
+				print_error(vformat("\x1b[94m[%d] \x1b[96m???\x1b[0m", n));
 			}
 
 			n++;