gdb/nat/windows-nat.h

   1 /* Internal interfaces for the Windows code
   2    Copyright (C) 1995-2020 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef NAT_WINDOWS_NAT_H
  20 #define NAT_WINDOWS_NAT_H
  21
  22 #include <windows.h>
  23 #include <vector>
  24
  25 #include "gdbsupport/gdb_optional.h"
  26 #include "target/waitstatus.h"
  27
  28 namespace windows_nat
  29 {
  30
  31 /* Thread information structure used to track extra information about
  32    each thread.  */
  33 struct windows_thread_info
  34 {
  35   windows_thread_info (DWORD tid_, HANDLE h_, CORE_ADDR tlb)
  36     : tid (tid_),
  37       h (h_),
  38       thread_local_base (tlb)
  39   {
  40   }
  41
  42   ~windows_thread_info ();
  43
  44   DISABLE_COPY_AND_ASSIGN (windows_thread_info);
  45
  46   /* Ensure that this thread has been suspended.  */
  47   void suspend ();
  48
  49   /* Resume the thread if it has been suspended.  */
  50   void resume ();
  51
  52   /* The Win32 thread identifier.  */
  53   DWORD tid;
  54
  55   /* The handle to the thread.  */
  56   HANDLE h;
  57
  58   /* Thread Information Block address.  */
  59   CORE_ADDR thread_local_base;
  60
  61   /* This keeps track of whether SuspendThread was called on this
  62      thread.  -1 means there was a failure or that the thread was
  63      explicitly not suspended, 1 means it was called, and 0 means it
  64      was not.  */
  65   int suspended = 0;
  66
  67 #ifdef _WIN32_WCE
  68   /* The context as retrieved right after suspending the thread. */
  69   CONTEXT base_context {};
  70 #endif
  71
  72   /* The context of the thread, including any manipulations.  */
  73   union
  74   {
  75     CONTEXT context {};
  76 #ifdef __x86_64__
  77     WOW64_CONTEXT wow64_context;
  78 #endif
  79   };
  80
  81   /* Whether debug registers changed since we last set CONTEXT back to
  82      the thread.  */
  83   bool debug_registers_changed = false;
  84
  85   /* Nonzero if CONTEXT is invalidated and must be re-read from the
  86      inferior thread.  */
  87   bool reload_context = false;
  88
  89   /* True if this thread is currently stopped at a software
  90      breakpoint.  This is used to offset the PC when needed.  */
  91   bool stopped_at_software_breakpoint = false;
  92
  93   /* The name of the thread, allocated by xmalloc.  */
  94   gdb::unique_xmalloc_ptr<char> name;
  95 };
  96
  97
  98 /* Possible values to pass to 'thread_rec'.  */
  99 enum thread_disposition_type
 100 {
 101   /* Do not invalidate the thread's context, and do not suspend the
 102      thread.  */
 103   DONT_INVALIDATE_CONTEXT,
 104   /* Invalidate the context, but do not suspend the thread.  */
 105   DONT_SUSPEND,
 106   /* Invalidate the context and suspend the thread.  */
 107   INVALIDATE_CONTEXT
 108 };
 109
 110 /* Find a thread record given a thread id.  THREAD_DISPOSITION
 111    controls whether the thread is suspended, and whether the context
 112    is invalidated.
 113
 114    This function must be supplied by the embedding application.  */
 115 extern windows_thread_info *thread_rec (ptid_t ptid,
 116                                         thread_disposition_type disposition);
 117
 118
 119 /* Handle OUTPUT_DEBUG_STRING_EVENT from child process.  Updates
 120    OURSTATUS and returns the thread id if this represents a thread
 121    change (this is specific to Cygwin), otherwise 0.
 122
 123    Cygwin prepends its messages with a "cygwin:".  Interpret this as
 124    a Cygwin signal.  Otherwise just print the string as a warning.
 125
 126    This function must be supplied by the embedding application.  */
 127 extern int handle_output_debug_string (struct target_waitstatus *ourstatus);
 128
 129 /* Handle a DLL load event.
 130
 131    This function assumes that the current event did not occur during
 132    inferior initialization.
 133
 134    This function must be supplied by the embedding application.  */
 135
 136 extern void handle_load_dll ();
 137
 138 /* Handle a DLL unload event.
 139
 140    This function assumes that this event did not occur during inferior
 141    initialization.
 142
 143    This function must be supplied by the embedding application.  */
 144
 145 extern void handle_unload_dll ();
 146
 147 /* Handle MS_VC_EXCEPTION when processing a stop.  MS_VC_EXCEPTION is
 148    somewhat undocumented but is used to tell the debugger the name of
 149    a thread.
 150
 151    Return true if the exception was handled; return false otherwise.
 152
 153    This function must be supplied by the embedding application.  */
 154
 155 extern bool handle_ms_vc_exception (const EXCEPTION_RECORD *rec);
 156
 157
 158 /* Currently executing process */
 159 extern HANDLE current_process_handle;
 160 extern DWORD current_process_id;
 161 extern DWORD main_thread_id;
 162 extern enum gdb_signal last_sig;
 163
 164 /* The current debug event from WaitForDebugEvent or from a pending
 165    stop.  */
 166 extern DEBUG_EVENT current_event;
 167
 168 /* The most recent event from WaitForDebugEvent.  Unlike
 169    current_event, this is guaranteed never to come from a pending
 170    stop.  This is important because only data from the most recent
 171    event from WaitForDebugEvent can be used when calling
 172    ContinueDebugEvent.  */
 173 extern DEBUG_EVENT last_wait_event;
 174
 175 /* Info on currently selected thread */
 176 extern windows_thread_info *current_windows_thread;
 177
 178 /* The ID of the thread for which we anticipate a stop event.
 179    Normally this is -1, meaning we'll accept an event in any
 180    thread.  */
 181 extern DWORD desired_stop_thread_id;
 182
 183 /* A single pending stop.  See "pending_stops" for more
 184    information.  */
 185 struct pending_stop
 186 {
 187   /* The thread id.  */
 188   DWORD thread_id;
 189
 190   /* The target waitstatus we computed.  */
 191   target_waitstatus status;
 192
 193   /* The event.  A few fields of this can be referenced after a stop,
 194      and it seemed simplest to store the entire event.  */
 195   DEBUG_EVENT event;
 196 };
 197
 198 /* A vector of pending stops.  Sometimes, Windows will report a stop
 199    on a thread that has been ostensibly suspended.  We believe what
 200    happens here is that two threads hit a breakpoint simultaneously,
 201    and the Windows kernel queues the stop events.  However, this can
 202    result in the strange effect of trying to single step thread A --
 203    leaving all other threads suspended -- and then seeing a stop in
 204    thread B.  To handle this scenario, we queue all such "pending"
 205    stops here, and then process them once the step has completed.  See
 206    PR gdb/22992.  */
 207 extern std::vector<pending_stop> pending_stops;
 208
 209 /* Contents of $_siginfo */
 210 extern EXCEPTION_RECORD siginfo_er;
 211
 212 /* Return the name of the DLL referenced by H at ADDRESS.  UNICODE
 213    determines what sort of string is read from the inferior.  Returns
 214    the name of the DLL, or NULL on error.  If a name is returned, it
 215    is stored in a static buffer which is valid until the next call to
 216    get_image_name.  */
 217 extern const char *get_image_name (HANDLE h, void *address, int unicode);
 218
 219 typedef enum
 220 {
 221   HANDLE_EXCEPTION_UNHANDLED = 0,
 222   HANDLE_EXCEPTION_HANDLED,
 223   HANDLE_EXCEPTION_IGNORED
 224 } handle_exception_result;
 225
 226 extern handle_exception_result handle_exception
 227   (struct target_waitstatus *ourstatus, bool debug_exceptions);
 228
 229 /* Return true if there is a pending stop matching
 230    desired_stop_thread_id.  If DEBUG_EVENTS is true, logging will be
 231    enabled.  */
 232
 233 extern bool matching_pending_stop (bool debug_events);
 234
 235 /* See if a pending stop matches DESIRED_STOP_THREAD_ID.  If so,
 236    remove it from the list of pending stops, set 'current_event', and
 237    return it.  Otherwise, return an empty optional.  */
 238
 239 extern gdb::optional<pending_stop> fetch_pending_stop (bool debug_events);
 240
 241 /* A simple wrapper for ContinueDebugEvent that continues the last
 242    waited-for event.  If DEBUG_EVENTS is true, logging will be
 243    enabled.  */
 244
 245 extern BOOL continue_last_debug_event (DWORD continue_status,
 246                                        bool debug_events);
 247
 248 /* A simple wrapper for WaitForDebugEvent that also sets
 249    'last_wait_event' on success.  */
 250
 251 extern BOOL wait_for_debug_event (DEBUG_EVENT *event, DWORD timeout);
 252
 253 }
 254
 255 #endif