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 #define STATUS_WX86_BREAKPOINT 0x4000001F
  29 #define STATUS_WX86_SINGLE_STEP 0x4000001E
  30
  31 namespace windows_nat
  32 {
  33
  34 /* Thread information structure used to track extra information about
  35    each thread.  */
  36 struct windows_thread_info
  37 {
  38   windows_thread_info (DWORD tid_, HANDLE h_, CORE_ADDR tlb)
  39     : tid (tid_),
  40       h (h_),
  41       thread_local_base (tlb)
  42   {
  43   }
  44
  45   ~windows_thread_info ();
  46
  47   DISABLE_COPY_AND_ASSIGN (windows_thread_info);
  48
  49   /* Ensure that this thread has been suspended.  */
  50   void suspend ();
  51
  52   /* Resume the thread if it has been suspended.  */
  53   void resume ();
  54
  55   /* The Win32 thread identifier.  */
  56   DWORD tid;
  57
  58   /* The handle to the thread.  */
  59   HANDLE h;
  60
  61   /* Thread Information Block address.  */
  62   CORE_ADDR thread_local_base;
  63
  64   /* This keeps track of whether SuspendThread was called on this
  65      thread.  -1 means there was a failure or that the thread was
  66      explicitly not suspended, 1 means it was called, and 0 means it
  67      was not.  */
  68   int suspended = 0;
  69
  70 #ifdef _WIN32_WCE
  71   /* The context as retrieved right after suspending the thread. */
  72   CONTEXT base_context {};
  73 #endif
  74
  75   /* The context of the thread, including any manipulations.  */
  76   union
  77   {
  78     CONTEXT context {};
  79 #ifdef __x86_64__
  80     WOW64_CONTEXT wow64_context;
  81 #endif
  82   };
  83
  84   /* Whether debug registers changed since we last set CONTEXT back to
  85      the thread.  */
  86   bool debug_registers_changed = false;
  87
  88   /* Nonzero if CONTEXT is invalidated and must be re-read from the
  89      inferior thread.  */
  90   bool reload_context = false;
  91
  92   /* True if this thread is currently stopped at a software
  93      breakpoint.  This is used to offset the PC when needed.  */
  94   bool stopped_at_software_breakpoint = false;
  95
  96   /* The name of the thread, allocated by xmalloc.  */
  97   gdb::unique_xmalloc_ptr<char> name;
  98 };
  99
 100
 101 /* Possible values to pass to 'thread_rec'.  */
 102 enum thread_disposition_type
 103 {
 104   /* Do not invalidate the thread's context, and do not suspend the
 105      thread.  */
 106   DONT_INVALIDATE_CONTEXT,
 107   /* Invalidate the context, but do not suspend the thread.  */
 108   DONT_SUSPEND,
 109   /* Invalidate the context and suspend the thread.  */
 110   INVALIDATE_CONTEXT
 111 };
 112
 113 /* Find a thread record given a thread id.  THREAD_DISPOSITION
 114    controls whether the thread is suspended, and whether the context
 115    is invalidated.
 116
 117    This function must be supplied by the embedding application.  */
 118 extern windows_thread_info *thread_rec (ptid_t ptid,
 119                                         thread_disposition_type disposition);
 120
 121
 122 /* Handle OUTPUT_DEBUG_STRING_EVENT from child process.  Updates
 123    OURSTATUS and returns the thread id if this represents a thread
 124    change (this is specific to Cygwin), otherwise 0.
 125
 126    Cygwin prepends its messages with a "cygwin:".  Interpret this as
 127    a Cygwin signal.  Otherwise just print the string as a warning.
 128
 129    This function must be supplied by the embedding application.  */
 130 extern int handle_output_debug_string (struct target_waitstatus *ourstatus);
 131
 132 /* Handle a DLL load event.
 133
 134    This function assumes that the current event did not occur during
 135    inferior initialization.
 136
 137    This function must be supplied by the embedding application.  */
 138
 139 extern void handle_load_dll ();
 140
 141 /* Handle a DLL unload event.
 142
 143    This function assumes that this event did not occur during inferior
 144    initialization.
 145
 146    This function must be supplied by the embedding application.  */
 147
 148 extern void handle_unload_dll ();
 149
 150 /* Handle MS_VC_EXCEPTION when processing a stop.  MS_VC_EXCEPTION is
 151    somewhat undocumented but is used to tell the debugger the name of
 152    a thread.
 153
 154    Return true if the exception was handled; return false otherwise.
 155
 156    This function must be supplied by the embedding application.  */
 157
 158 extern bool handle_ms_vc_exception (const EXCEPTION_RECORD *rec);
 159
 160 /* When EXCEPTION_ACCESS_VIOLATION is processed, we give the embedding
 161    application a chance to change it to be considered "unhandled".
 162    This function must be supplied by the embedding application.  If it
 163    returns true, then the exception is "unhandled".  */
 164
 165 extern bool handle_access_violation (const EXCEPTION_RECORD *rec);
 166
 167
 168 /* Currently executing process */
 169 extern HANDLE current_process_handle;
 170 extern DWORD current_process_id;
 171 extern DWORD main_thread_id;
 172 extern enum gdb_signal last_sig;
 173
 174 /* The current debug event from WaitForDebugEvent or from a pending
 175    stop.  */
 176 extern DEBUG_EVENT current_event;
 177
 178 /* Info on currently selected thread */
 179 extern windows_thread_info *current_windows_thread;
 180
 181 /* The ID of the thread for which we anticipate a stop event.
 182    Normally this is -1, meaning we'll accept an event in any
 183    thread.  */
 184 extern DWORD desired_stop_thread_id;
 185
 186 /* A single pending stop.  See "pending_stops" for more
 187    information.  */
 188 struct pending_stop
 189 {
 190   /* The thread id.  */
 191   DWORD thread_id;
 192
 193   /* The target waitstatus we computed.  */
 194   target_waitstatus status;
 195
 196   /* The event.  A few fields of this can be referenced after a stop,
 197      and it seemed simplest to store the entire event.  */
 198   DEBUG_EVENT event;
 199 };
 200
 201 /* A vector of pending stops.  Sometimes, Windows will report a stop
 202    on a thread that has been ostensibly suspended.  We believe what
 203    happens here is that two threads hit a breakpoint simultaneously,
 204    and the Windows kernel queues the stop events.  However, this can
 205    result in the strange effect of trying to single step thread A --
 206    leaving all other threads suspended -- and then seeing a stop in
 207    thread B.  To handle this scenario, we queue all such "pending"
 208    stops here, and then process them once the step has completed.  See
 209    PR gdb/22992.  */
 210 extern std::vector<pending_stop> pending_stops;
 211
 212 /* Contents of $_siginfo */
 213 extern EXCEPTION_RECORD siginfo_er;
 214
 215 #ifdef __x86_64__
 216 /* Ignore first breakpoint exception of WOW64 process */
 217 extern bool ignore_first_breakpoint;
 218 #endif
 219
 220 /* Return the name of the DLL referenced by H at ADDRESS.  UNICODE
 221    determines what sort of string is read from the inferior.  Returns
 222    the name of the DLL, or NULL on error.  If a name is returned, it
 223    is stored in a static buffer which is valid until the next call to
 224    get_image_name.  */
 225 extern const char *get_image_name (HANDLE h, void *address, int unicode);
 226
 227 typedef enum
 228 {
 229   HANDLE_EXCEPTION_UNHANDLED = 0,
 230   HANDLE_EXCEPTION_HANDLED,
 231   HANDLE_EXCEPTION_IGNORED
 232 } handle_exception_result;
 233
 234 extern handle_exception_result handle_exception
 235   (struct target_waitstatus *ourstatus, bool debug_exceptions);
 236
 237 /* Return true if there is a pending stop matching
 238    desired_stop_thread_id.  If DEBUG_EVENTS is true, logging will be
 239    enabled.  */
 240
 241 extern bool matching_pending_stop (bool debug_events);
 242
 243 /* See if a pending stop matches DESIRED_STOP_THREAD_ID.  If so,
 244    remove it from the list of pending stops, set 'current_event', and
 245    return it.  Otherwise, return an empty optional.  */
 246
 247 extern gdb::optional<pending_stop> fetch_pending_stop (bool debug_events);
 248
 249 /* A simple wrapper for ContinueDebugEvent that continues the last
 250    waited-for event.  If DEBUG_EVENTS is true, logging will be
 251    enabled.  */
 252
 253 extern BOOL continue_last_debug_event (DWORD continue_status,
 254                                        bool debug_events);
 255
 256 /* A simple wrapper for WaitForDebugEvent that also sets the internal
 257    'last_wait_event' on success.  */
 258
 259 extern BOOL wait_for_debug_event (DEBUG_EVENT *event, DWORD timeout);
 260
 261 }
 262
 263 #endif