1 files changed, 85 insertions, 0 deletions
diff --git a/src/mongo/util/debug_util.cpp b/src/mongo/util/debug_util.cpp
new file mode 100644
index 00000000000..e217fe7e51d
--- /dev/null
+++ b/src/mongo/util/debug_util.cpp
@@ -0,0 +1,85 @@
+// debug_util.cpp
+
+/*    Copyright 2009 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#include "pch.h"
+#ifndef _WIN32
+#include <signal.h>
+#endif
+
+#if defined(USE_GDBSERVER)
+#include "mongo/db/cmdline.h"
+#include "mongo/db/jsobj.h"
+#endif  // defined(USE_GDBSERVER)
+
+namespace mongo {
+    void mongo_breakpoint() {
+#ifdef _WIN32
+        DEV DebugBreak();
+#endif
+#ifndef _WIN32
+        // code to raise a breakpoint in GDB
+        ONCE {
+            //prevent SIGTRAP from crashing the program if default action is specified and we are not in gdb
+            struct sigaction current;
+            sigaction(SIGTRAP, NULL, &current);
+            if (current.sa_handler == SIG_DFL) {
+                signal(SIGTRAP, SIG_IGN);
+            }
+        }
+
+        raise(SIGTRAP);
+#endif
+    }
+
+#if defined(USE_GDBSERVER)
+
+    /* Magic gdb trampoline
+     * Do not call directly! call setupSIGTRAPforGDB()
+     * Assumptions:
+     *  1) gdbserver is on your path
+     *  2) You have run "handle SIGSTOP noprint" in gdb
+     *  3) cmdLine.port + 2000 is free
+     */
+    void launchGDB(int) {
+        // Don't come back here
+        signal(SIGTRAP, SIG_IGN);
+
+        int newPort = cmdLine.port + 2000;
+        string newPortStr = "localhost:" + BSONObjBuilder::numStr(newPort);
+        string pidToDebug = BSONObjBuilder::numStr(getpid());
+
+        cout << "\n\n\t**** Launching gdbserver on " << newPortStr << " ****" << endl << endl;
+        if (fork() == 0) {
+            //child
+            execlp("gdbserver", "gdbserver", "--attach", newPortStr.c_str(), pidToDebug.c_str(), NULL);
+            perror(NULL);
+        }
+        else {
+            //parent
+            raise(SIGSTOP); // pause all threads until gdb connects and continues
+            raise(SIGTRAP); // break inside gdbserver
+        }
+    }
+
+    void setupSIGTRAPforGDB() {
+        verify( signal(SIGTRAP , launchGDB ) != SIG_ERR );
+    }
+#else
+    void setupSIGTRAPforGDB() {
+    }
+#endif
+}