[*] Initial commit

lonetix/sys/dbg_unix.c

@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+/**
+ * \file sys/dbg_unix.c
+ *
+ * Implements debugging utilities for Unix platforms.
+ *
+ * \copyright The DoubleFourteen Code Forge (C) All Rights Reserved
+ * \author    Lorenzo Cogotti
+ */
+
+#include "sys/dbg.h"
+
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifdef __GNUC__
+#include <execinfo.h>
+#endif
+
+Boolean Sys_IsDebuggerPresent(void)
+{
+#ifdef __linux__
+	// Read process status file
+	char buf[4096];
+
+	int fd = open("/proc/self/status", O_RDONLY);
+	if (fd < 0)
+		return FALSE;
+
+	ssize_t n = read(fd, buf, sizeof(buf) - 1);
+	close(fd);
+
+	if (n < 0)
+		return FALSE;
+
+	buf[n] = '\0';
+
+	const char *tracer = "TracerPid:\t";
+	const char *pos    = strstr(buf, tracer);
+	if (!pos)
+		return FALSE;
+
+	pos += strlen(tracer);
+
+	pid_t pid = atol(pos);
+	return pid > 0;
+
+#else
+	// TODO MacOS, BSD via sysctl()
+	// http://developer.apple.com/qa/qa2004/qa1361.html
+	// https://github.com/chromium/chromium/blob/master/base/debug/debugger_posix.cc
+	return FALSE;
+#endif
+}
+
+size_t Sys_GetBacktrace(void **dest, size_t n)
+{
+	USED(dest);
+	USED(n);
+
+#ifdef __GNUC__
+	if (n > (size_t) (INT_MAX - 1))
+		n = INT_MAX - 1;
+
+	void **trace = (void **) alloca(sizeof(*trace) * (n + 1));
+
+	int res = backtrace(trace, n + 1);
+	if (res > 0) {
+		// Exclude ourselves from the trace
+		res--;
+
+		memcpy(dest, trace + 1, res * sizeof(*dest));
+		return res;
+	}
+#endif
+
+	return 0;
+}
+
+void *Sys_GetCaller(void)
+{
+#ifdef __GNUC__
+	void *trace[3];  // ourselves, caller, caller's caller
+
+	int n = backtrace(trace, ARRAY_SIZE(trace));
+	if (n == ARRAY_SIZE(trace))
+		return trace[2];
+
+#endif
+
+	return NULL;
+}
+
+char *Sys_GetSymbolName(void *sym)
+{
+	USED(sym);
+
+#ifdef __GNUC__
+	static THREAD_LOCAL char buf[128];
+
+	char **names = backtrace_symbols(&sym, 1);
+	if (names) {
+		size_t n = strlen(names[0]);
+		if (n > sizeof(buf) - 1) {
+			// Truncate symbol
+			n = sizeof(buf) - 4;
+
+			memcpy(buf, names[0], n);
+			buf[n+0] = '.'; buf[n+1] = '.'; buf[n+2] = '.';
+			buf[n+3] = '\0';
+
+		} else {
+			memcpy(buf, names[0], n + 1);
+		}
+
+		free(names);
+		return buf;
+	}
+#endif
+
+	return NULL;
+}
+
+void Sys_DumpBacktrace(ConHn hn, void **trace, size_t n)
+{
+	USED(hn);
+	USED(trace);
+	USED(n);
+
+#ifdef __GNUC__
+	backtrace_symbols_fd(trace, MIN(n, (size_t) INT_MAX), hn);
+#endif
+}