4 files changed, 288 insertions, 0 deletions
diff --git a/gdb-wrapper2/Makefile b/gdb-wrapper2/Makefile
new file mode 100644
index 0000000..bba6e44
--- /dev/null
+++ b/gdb-wrapper2/Makefile
@@ -0,0 +1,10 @@
+test_program: test_program.c
+	cc test_program.c -o test_program $(CFLAGS) $(LDFLAGS)
+
+test: test.sh test_program
+	./test.sh
+
+clean:
+	rm test_program
+
+.PHONY: clean
diff --git a/gdb-wrapper2/gdb-wrapper2.sh b/gdb-wrapper2/gdb-wrapper2.sh
new file mode 100755
index 0000000..c60b649
--- /dev/null
+++ b/gdb-wrapper2/gdb-wrapper2.sh
@@ -0,0 +1,92 @@
+#!/bin/bash
+
+# gdb-wrapper2
+# Copyright (C) 2017  Paweł Redman <pawel.redman@gmail.com>
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+SELF="$0"
+PROGRAM="$1"
+shift 1
+
+if [ -z "$PROGRAM" ]; then
+        echo "$SELF [program] (args...)"
+        exit 1
+fi
+
+# Check if the program exists before calling GDB so the errors are clearer.
+if [ ! -f "$PROGRAM" ]; then
+	stat "$PROGRAM"
+	exit 1
+fi
+
+# 'catch' and 'break' can be followed by a 'commands' block to tell GDB what
+# to do in case of a breakpoint/signal. This is where the stack is printed
+# and the core is dumped. 
+function write_commands {
+	echo "commands"
+		echo "thread apply all backtrace"
+		echo "gcore"
+		echo "echo \n"
+
+		# Terminate if this isn't the first fault to avoid infinite
+		# recursion.
+		echo "set \$faults = \$faults + 1"
+		echo "if \$faults >= 2"
+			echo "echo Double fault, terminating the program.\n"
+			echo "kill"
+			echo "quit"
+		echo "else"
+			# Resume the program's execution.
+			# If the program can handle signals and exit gracefully
+			# then this script should let it (after dumping a core
+			# for debugging).
+			echo "continue"
+		echo "end"
+	echo "end"
+}
+
+function write_config {
+	# Make sure gdb won't ask for interactive input. This is supposed
+	# to never happen when using -batch but I don't trust them.
+	echo "set confirm off"
+	echo "set width unlimited"
+	echo "set height unlimited"
+	echo "set pagination off"
+	echo "set backtrace limit unlimited"
+
+	echo "set \$faults = 0"
+
+	# This catches all signals except SIGINT and SIGTRAP.
+	echo "catch signal"
+	write_commands
+
+	# Catch SIGINT too, just in case.
+	echo "catch signal SIGINT"
+	write_commands
+
+	# Catch calls to Com_Error. You'll want something else here if you're
+	# using this script for another program.
+	echo "break Com_Error"
+	write_commands
+
+	# Finally start the program.
+	echo "run"
+}
+
+# Disable automatic coredumps.
+ulimit -c 0
+
+# For some reason gdb's '-x' option won't accept a pipe as an argument. The
+# workaround is to create a temporary file for the configuration.
+config_path=$(mktemp /tmp/gdb-wrapper2.XXXXXX)
+write_config > "$config_path"
+
+gdb -batch -x "$config_path" --args "$PROGRAM" "$@"
+exit_status="$?"
+
+rm "$config_path"
+exit $exit_status
diff --git a/gdb-wrapper2/test.sh b/gdb-wrapper2/test.sh
new file mode 100755
index 0000000..f5fea63
--- /dev/null
+++ b/gdb-wrapper2/test.sh
@@ -0,0 +1,32 @@
+#!/bin/bash
+
+function do_test {
+	../gdb-wrapper2.sh ./test_program --verbose "$@"
+}
+
+function title {
+	tput bold
+	tput setaf 3
+	echo "$@"
+	echo
+	tput sgr0
+}
+
+title "Test: Raise 11."
+do_test --raise 11
+
+title "Test: Raise and catch 11."
+do_test --raise 11 --catch 11
+
+title "Test: Raise then keep recursively catching 11."
+do_test --raise 11 --catch 11 --recursive
+
+title "Test: Call Com_Error."
+do_test --Com_Error
+
+title "Test: Call Com_Error then keep recursively calling it."
+do_test --Com_Error --recursive
+
+title "Test: Raise but ignore 2."
+do_test --raise 2 --ignore 2
+
diff --git a/gdb-wrapper2/test_program.c b/gdb-wrapper2/test_program.c
new file mode 100644
index 0000000..e332d5f
--- /dev/null
+++ b/gdb-wrapper2/test_program.c
@@ -0,0 +1,154 @@
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <signal.h>
+
+#define MAX_SIGNALS 32
+
+#define print(fmt, ...) fprintf(stderr, "test_program: "fmt, ##__VA_ARGS__)
+
+_Bool do_raise = 0;
+int raise_signal;   
+_Bool do_Com_Error = 0;
+_Bool recursive = 0;
+
+enum { DEFAULT = 0, CATCH, IGNORE };
+int handle[MAX_SIGNALS] = {0};
+_Bool handle_any = 0;
+
+_Bool verbose = 0;
+
+static int read_args(int argc, char **argv)
+{
+	for (int i = 1; i < argc; i++) {
+		if (!strcmp(argv[i], "--raise")) {
+			if (i + 1 >= argc)
+				goto needs_argument;
+
+			do_raise = 1;
+			raise_signal = atoi(argv[i + 1]);
+			i++;
+		} else if (!strcmp(argv[i], "--Com_Error")) {
+			do_Com_Error = 1;
+		} else if (!strcmp(argv[i], "--recursive")) {
+			recursive = 1;
+		} else if (!strcmp(argv[i], "--catch") ||
+		           !strcmp(argv[i], "--ignore")) {
+			int sig;
+
+			if (i + 1 >= argc)
+				goto needs_argument;
+
+			sig = atoi(argv[i + 1]);
+			if (sig < 0 || sig >= MAX_SIGNALS) {
+				print("invalid argument for --catch/--ignore: %i\n",
+				      sig);
+				return 1;
+			}
+
+			if (!strcmp(argv[i], "--catch"))
+				handle[sig] = CATCH;
+			else
+				handle[sig] = IGNORE;
+
+			handle_any = 1;
+			i++;
+		} else if (!strcmp(argv[i], "--ignore")) {
+			
+		} else if (!strcmp(argv[i], "--verbose")) {
+			verbose = 1;
+		} else {
+			print("invalid option '%s'\n", argv[i]);
+			return 1;
+		}
+
+		continue;
+	needs_argument:
+		print("option '%s' needs an argument\n", argv[i]);
+		return 1;
+	}
+
+	if (do_Com_Error && do_raise) {
+		print("--raise and --Com_Error are mutually exclusive.\n");
+		return 1;
+	}
+
+	return 0;
+}
+
+_Noreturn void graceful_exit(void)
+{
+	print("Graceful exit.\n");
+	exit(0);
+}
+
+void signal_catcher(int sig)
+{
+	print("Caught signal %i.\n", sig);
+
+	if (recursive) {
+		if (verbose)
+			print("Raising signal %i from within the handler.\n",
+			      raise_signal);
+		raise(raise_signal);
+	}
+
+	graceful_exit();
+}
+
+_Noreturn void Com_Error(int type, const char *str)
+{
+	print("Com_Error: %s\n", str);
+
+	if (recursive)
+		Com_Error(666, "Error while erroring");
+
+	graceful_exit();
+}
+
+int main(int argc, char **argv)
+{
+	int rv;
+
+	rv = read_args(argc, argv);
+	if (rv)
+		return rv;
+
+	for (int i = 0; i < MAX_SIGNALS; i++) {
+		void (*fun)(int);
+
+		switch (handle[i]) {
+		case DEFAULT:
+			continue;
+
+		case CATCH:
+			fun = signal_catcher;
+			if (verbose)
+				print("Signal %i will be caught.\n", i);
+			break;
+
+		case IGNORE:
+			fun = SIG_IGN;
+			if (verbose)
+				print("Signal %i will be ignored.\n", i);
+			break;
+		}
+
+		if (signal(i, fun) == SIG_ERR) {
+			print("For signal %i: ", i);
+			perror("signal");
+			return 1;
+		}
+	}
+
+	if (do_raise) {
+		print("Raising signal %i.\n", raise_signal);
+		raise(raise_signal);
+	}
+
+	if (do_Com_Error)
+		Com_Error(123, "Some error string");
+
+	print("Reached the end of main().\n");
+	graceful_exit();
+}