From 430dba3398d71027e9ba83faf3b7ce0ba70bda03 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=A0=D1=83=D1=81=D0=BB=D0=B0=D0=BD=20=D0=98=D0=B6=D0=B1=D1?=
 =?UTF-8?q?=83=D0=BB=D0=B0=D1=82=D0=BE=D0=B2?= <lrn1986@gmail.com>
Date: Sat, 26 Nov 2011 14:15:01 +0400
Subject: [PATCH] Add W32 VEH

---
 src/util/winproc.c |   77 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 77 insertions(+), 0 deletions(-)

diff --git a/src/util/winproc.c b/src/util/winproc.c
index b524531..52a4e24 100644
--- a/src/util/winproc.c
+++ b/src/util/winproc.c
@@ -32,6 +32,9 @@
 #ifdef MINGW
 
 static HINSTANCE hNTDLL, hIphlpapi, hAdvapi, hNetapi;
+#ifdef W32_VEH
+static void *GNWinVEH_handle = NULL;
+#endif
 
 TNtQuerySystemInformation GNNtQuerySystemInformation;
 TGetIfEntry GNGetIfEntry;
@@ -77,6 +80,60 @@ plibc_panic (int err, char *msg)
        "%s", msg);
 }
 
+#ifdef W32_VEH
+/**
+ * Handles exceptions (useful for debugging).
+ * Issues a DebugBreak() call if the process is being debugged (not really
+ * useful - if the process is being debugged, this handler won't be invoked
+ * anyway). If it is not, runs a debugger from GNUNET_DEBUGGER env var,
+ * substituting first %u in it for PID, and the second one for the event,
+ * that should be set once the debugger attaches itself (otherwise the
+ * only way out of WaitForSingleObject() is to time out after 1 minute).
+ */
+LONG __stdcall
+GNWinVEH (PEXCEPTION_POINTERS ExceptionInfo)
+{
+  char debugger[MAX_PATH + 1];
+  char *debugger_env = NULL;
+  if (IsDebuggerPresent ())
+  {
+    DebugBreak ();
+    return EXCEPTION_CONTINUE_EXECUTION;
+  }
+  debugger_env = getenv ("GNUNET_DEBUGGER");
+  if (debugger_env != NULL)
+  {
+    STARTUPINFO si;
+    PROCESS_INFORMATION pi;
+    HANDLE event;
+    SECURITY_ATTRIBUTES sa;
+    memset (&si, 0, sizeof (si));
+    si.cb = sizeof (si);
+    memset (&pi, 0, sizeof (pi));
+    memset (&sa, 0, sizeof (sa));
+    sa.nLength = sizeof (sa);
+    sa.bInheritHandle = TRUE;
+    event = CreateEvent (&sa, FALSE, FALSE, NULL);
+    snprintf (debugger, MAX_PATH + 1, debugger_env, GetCurrentProcessId (), (uintptr_t) event);
+    debugger[MAX_PATH] = '\0';
+    if (0 != CreateProcessA (NULL, debugger, NULL, NULL, TRUE, CREATE_NEW_CONSOLE, NULL, NULL, &si, &pi))
+    {
+      CloseHandle (pi.hProcess);
+      CloseHandle (pi.hThread);
+      WaitForSingleObject (event, 60000);
+      CloseHandle (event);
+      if (IsDebuggerPresent ())
+      {
+        return EXCEPTION_CONTINUE_EXECUTION;
+      }
+    }
+    else
+      CloseHandle (event);
+  }
+  return EXCEPTION_CONTINUE_SEARCH;
+}
+#endif
+
 /**
  * @brief Initialize PlibC and set up Windows environment
  * @param logging context, NULL means stderr
@@ -95,6 +152,18 @@ GNInitWinEnv ()
   if (hNTDLL)
     return ret;
 
+#ifdef W32_VEH
+  if (GNWinVEH_handle == NULL)
+  {
+    GNWinVEH_handle = AddVectoredExceptionHandler (1, &GNWinVEH);
+    if (GNWinVEH_handle == NULL)
+    {
+      /* This is bad, but what can we do? */
+      printf ("Failed to set up an exception handler!\n");
+    }
+  }
+#endif
+
   hNTDLL = LoadLibrary ("ntdll.dll");
 
   /* Function to get CPU usage under Win NT */
@@ -242,6 +311,14 @@ GNShutdownWinEnv ()
 {
   plibc_shutdown ();
 
+#ifdef W32_VEH
+  if (GNWinVEH_handle != NULL)
+  {
+    RemoveVectoredExceptionHandler (GNWinVEH_handle);
+    GNWinVEH_handle = NULL;
+  }
+#endif
+
   FreeLibrary (hNTDLL);
   FreeLibrary (hIphlpapi);
   FreeLibrary (hAdvapi);
-- 
1.7.4