Move backtrace generation behind cmake flag

CMakeLists.txt

@@ -7,6 +7,8 @@ option( ENABLE_EXAMPLES "Install additional tin2rc examples" ON )
 option( ENABLE_RSVG "Rsvg support (launcher only)" ON )
 option( ENABLE_SN "Startup notification support" ON )
 option( ENABLE_ASAN "Build tint2 with AddressSanitizer" OFF )
+option( ENABLE_BACKTRACE "Dump a backtrace in case of fatal errors (e.g. X11 I/O error)" ON )
+option( ENABLE_BACKTRACE_ON_SIGNAL "Dump a backtrace also when receiving signals such as SIGSEGV" ON )
 if( CMAKE_SYSTEM_NAME STREQUAL "Linux" )
   option( ENABLE_UEVENT "Kernel event handling support" ON )
 endif( CMAKE_SYSTEM_NAME STREQUAL "Linux" )
@@ -22,24 +24,33 @@ pkg_check_modules( GLIB2 REQUIRED glib-2.0 )
 pkg_check_modules( GOBJECT2 REQUIRED gobject-2.0 )
 pkg_check_modules( IMLIB2 REQUIRED imlib2>=1.4.2 )
 
-check_c_source_compiles(
+if(ENABLE_BACKTRACE)
-	"#include <stdlib.h>\n#include <execinfo.h>\nint main () { backtrace(NULL, 0); }"
+	check_c_source_compiles(
-	BACKTRACE_LIBC)
+		"#include <stdlib.h>\n#include <execinfo.h>\nint main () { backtrace(NULL, 0); }"
+		BACKTRACE_LIBC)
 
-if(BACKTRACE_LIBC)
+	if(BACKTRACE_LIBC)
-	set(BACKTRACE_LIBC_FOUND TRUE)
+		set(BACKTRACE_LIBC_FOUND TRUE)
-	set(BACKTRACE_L_FLAGS "-rdynamic")
-else()
-	pkg_check_modules( UNWIND libunwind )
-	find_library(EXECINFO_LIBRARIES NAMES execinfo)
-	if(EXECINFO_LIBRARIES OR EXECINFO_LIBRARIES_FOUND)
-		set(EXECINFO_FOUND TRUE)
-		set(EXECINFO_LIBRARIES "-lexecinfo")
 		set(BACKTRACE_L_FLAGS "-rdynamic")
 	else()
-		set(EXECINFO_LIBRARIES "")
+		pkg_check_modules( UNWIND libunwind )
-		set(BACKTRACE_L_FLAGS "")
+		find_library(EXECINFO_LIBRARIES NAMES execinfo)
+		if(EXECINFO_LIBRARIES OR EXECINFO_LIBRARIES_FOUND)
+			set(EXECINFO_FOUND TRUE)
+			set(EXECINFO_LIBRARIES "-lexecinfo")
+			set(BACKTRACE_L_FLAGS "-rdynamic")
+		else()
+			set(EXECINFO_LIBRARIES "")
+			set(BACKTRACE_L_FLAGS "")
+		endif()
 	endif()
+
+	if( NOT BACKTRACE_LIBC_FOUND AND NOT UNWIND_FOUND AND NOT EXECINFO_FOUND )
+	  message( WARNING "Backtrace support not available. You can enable it by installing libexecinfo or libunwind." )
+	endif()
+else()
+	set(EXECINFO_LIBRARIES "")
+	set(BACKTRACE_L_FLAGS "")
 endif()
 
 if( ENABLE_RSVG )
@@ -63,10 +74,6 @@ if( NOT IMLIB_BUILD_WITH_X )
   message( FATAL_ERROR "Imlib is not built with X support" )
 endif( NOT IMLIB_BUILD_WITH_X )
 
-if( NOT BACKTRACE_LIBC_FOUND AND NOT UNWIND_FOUND AND NOT EXECINFO_FOUND )
-  message( WARNING "Backtrace support not available. You can enable it by installing libexecinfo or libunwind." )
-endif()
-
 add_definitions( -D_GNU_SOURCE )
 
 include_directories( ${PROJECT_BINARY_DIR}
@@ -154,18 +161,26 @@ if( ENABLE_UEVENT )
   set( SOURCES ${SOURCES} src/util/uevent.c)
 endif( ENABLE_UEVENT )
 
-if(BACKTRACE_LIBC_FOUND)
+if(ENABLE_BACKTRACE)
-  add_definitions( -DENABLE_EXECINFO )
+	if(BACKTRACE_LIBC_FOUND)
+	  add_definitions( -DENABLE_EXECINFO )
+	endif()
+
+	if( UNWIND_FOUND )
+	  add_definitions( -DENABLE_LIBUNWIND )
+	endif( UNWIND_FOUND )
+
+	if( EXECINFO_FOUND )
+	  add_definitions( -DENABLE_EXECINFO )
+	endif( EXECINFO_FOUND )
+
+	if(ENABLE_BACKTRACE_ON_SIGNAL)
+		add_definitions( -DBACKTRACE_ON_SIGNAL )
+	endif()
+else()
+	add_definitions( -DDISABLE_BACKTRACE )
 endif()
 
-if( UNWIND_FOUND )
-  add_definitions( -DENABLE_LIBUNWIND )
-endif( UNWIND_FOUND )
-
-if( EXECINFO_FOUND )
-  add_definitions( -DENABLE_EXECINFO )
-endif( EXECINFO_FOUND )
-
 if( ENABLE_TINT2CONF )
   add_definitions( -DHAVE_VERSION_H )
   add_subdirectory( src/tint2conf )

src/tint.c

@@ -221,7 +221,9 @@ void dump_backtrace(int log_fd)
 
 	free(strings);
 #else
-	log_string(log_fd, "Backtrace not supported on this system. Install libunwind or libexecinfo.\n");
+#ifdef DISABLE_BACKTRACE
+	log_string(log_fd, "Backtrace support disabled at compile time.\n");
+#endif
 #endif
 #endif
 	log_string(log_fd, RESET);
@@ -251,13 +253,17 @@ void handle_crash(const char *reason)
 	dump_backtrace(log_fd);
 	log_string(log_fd, RED "Please create a bug report with this log output.\n" RESET);
 	close(log_fd);
-	exit(-1);
 }
 
+#ifdef BACKTRACE_ON_SIGNAL
 void crash_handler(int sig)
 {
 	handle_crash(signal_name(sig));
+	struct sigaction sa = {.sa_handler = SIG_DFL};
+	sigaction(sig, &sa, 0);
+	raise(sig);
 }
+#endif
 
 void x11_io_error(Display *display)
 {
@@ -322,18 +328,20 @@ void init(int argc, char *argv[])
 	signal_pending = 0;
 	struct sigaction sa = {.sa_handler = signal_handler};
 	struct sigaction sa_chld = {.sa_handler = SIG_DFL, .sa_flags = SA_NOCLDWAIT};
-	struct sigaction sa_crash = {.sa_handler = crash_handler};
 	sigaction(SIGUSR1, &sa, 0);
 	sigaction(SIGINT, &sa, 0);
 	sigaction(SIGTERM, &sa, 0);
 	sigaction(SIGHUP, &sa, 0);
 	sigaction(SIGCHLD, &sa_chld, 0);
+#ifdef BACKTRACE_ON_SIGNAL
+	struct sigaction sa_crash = {.sa_handler = crash_handler};
 	sigaction(SIGSEGV, &sa_crash, 0);
 	sigaction(SIGFPE, &sa_crash, 0);
 	sigaction(SIGPIPE, &sa_crash, 0);
 	sigaction(SIGBUS, &sa_crash, 0);
 	sigaction(SIGABRT, &sa_crash, 0);
 	sigaction(SIGSYS, &sa_crash, 0);
+#endif
 }
 
 static int sn_pipe_valid = 0;