[gdbserver/win32] (8/11) Tweak attach code to also support Windows CE

[Pedro Alves <pedro_alves@portugalmail.pt>]

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Hi,

Adding Windows CE attaching support, I saw that
the DebugActiveProcess call was failing with
"invalid handle".  It turns out that on Windows CE,
we can only call DebugActiveProcess if we have an open
handle to the process we're attaching to.

This patch simply reverses the order of the DebugActiveProcess,
OpenProcess calls, so that OpenProcess is done first.  As a
side effect, if OpenProcess fails, we don't need to undo the
DebugActiveProcess with DebugActiveProcessStop any more.

Tested on i686-pc-cygwin and arm-wince-mingw32ce.

Cheers,
Pedro Alves



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2007-11-12  Pedro Alves  <pedro_alves@portugalmail.pt>

	* win32-low.c (win32_attach): Call OpenProcess before
	DebugActiveProcess, not after.  Add last error output to error
	call.

---
 gdb/gdbserver/win32-low.c |   32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

Index: src/gdb/gdbserver/win32-low.c
===================================================================
--- src.orig/gdb/gdbserver/win32-low.c	2007-11-11 23:16:02.000000000 +0000
+++ src/gdb/gdbserver/win32-low.c	2007-11-11 23:16:12.000000000 +0000
@@ -754,34 +754,36 @@ win32_create_inferior (char *program, ch
 static int
 win32_attach (unsigned long pid)
 {
-  winapi_DebugActiveProcessStop DebugActiveProcessStop = NULL;
+  HANDLE h;
   winapi_DebugSetProcessKillOnExit DebugSetProcessKillOnExit = NULL;
+  DWORD err;
 #ifdef _WIN32_WCE
   HMODULE dll = GetModuleHandle (_T("COREDLL.DLL"));
 #else
   HMODULE dll = GetModuleHandle (_T("KERNEL32.DLL"));
 #endif
-  DebugActiveProcessStop = GETPROCADDRESS (dll, DebugActiveProcessStop);
   DebugSetProcessKillOnExit = GETPROCADDRESS (dll, DebugSetProcessKillOnExit);
 
-  if (DebugActiveProcess (pid))
+  h = OpenProcess (PROCESS_ALL_ACCESS, FALSE, pid);
+  if (h != NULL)
     {
-      if (DebugSetProcessKillOnExit != NULL)
- 	DebugSetProcessKillOnExit (FALSE);
+      if (DebugActiveProcess (pid))
+	{
+	  if (DebugSetProcessKillOnExit != NULL)
+	    DebugSetProcessKillOnExit (FALSE);
 
-      current_process_handle = OpenProcess (PROCESS_ALL_ACCESS, FALSE, pid);
+	  current_process_handle = h;
+	  current_process_id = pid;
+	  do_initial_child_stuff (pid);
+	  return 0;
+	}
 
-      if (current_process_handle != NULL)
- 	{
- 	  current_process_id = pid;
- 	  do_initial_child_stuff (pid);
- 	  return 0;
- 	}
-      if (DebugActiveProcessStop != NULL)
-	DebugActiveProcessStop (current_process_id);
+      CloseHandle (h);
     }
 
-  error ("Attach to process failed.");
+  err = GetLastError ();
+  error ("Attach to process failed (error %d): %s\n",
+	 (int) err, strwinerror (err));
 }
 
 /* Handle OUTPUT_DEBUG_STRING_EVENT from child process.  */