Watchpoint.cpp revision 36da2aa6dc5ad9994b638ed09eb81c44cc05540b
1//===-- Watchpoint.cpp ------------------------------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9 10#include "lldb/Breakpoint/Watchpoint.h" 11 12// C Includes 13// C++ Includes 14// Other libraries and framework includes 15// Project includes 16#include "lldb/Breakpoint/StoppointCallbackContext.h" 17#include "lldb/Core/Stream.h" 18#include "lldb/Core/Value.h" 19#include "lldb/Core/ValueObject.h" 20#include "lldb/Core/ValueObjectMemory.h" 21#include "lldb/Symbol/ClangASTContext.h" 22#include "lldb/Target/Process.h" 23#include "lldb/Target/Target.h" 24#include "lldb/Target/ThreadSpec.h" 25#include "lldb/Expression/ClangUserExpression.h" 26 27using namespace lldb; 28using namespace lldb_private; 29 30Watchpoint::Watchpoint (Target& target, lldb::addr_t addr, uint32_t size, const ClangASTType *type, bool hardware) : 31 StoppointLocation (0, addr, size, hardware), 32 m_target(target), 33 m_enabled(false), 34 m_is_hardware(hardware), 35 m_is_watch_variable(false), 36 m_is_ephemeral(false), 37 m_disabled_count(0), 38 m_watch_read(0), 39 m_watch_write(0), 40 m_watch_was_read(0), 41 m_watch_was_written(0), 42 m_ignore_count(0), 43 m_false_alarms(0), 44 m_decl_str(), 45 m_watch_spec_str(), 46 m_type(), 47 m_error(), 48 m_options (), 49 m_being_created(true) 50{ 51 if (type && type->IsValid()) 52 m_type = *type; 53 else 54 { 55 // If we don't have a known type, then we force it to unsigned int of the right size. 56 ClangASTContext *ast_context = target.GetScratchClangASTContext(); 57 clang_type_t clang_type = ast_context->GetBuiltinTypeForEncodingAndBitSize(eEncodingUint, 8 * size); 58 m_type.SetClangType(ast_context->getASTContext(), clang_type); 59 } 60 61 // Set the initial value of the watched variable: 62 if (m_target.GetProcessSP()) 63 { 64 ExecutionContext exe_ctx; 65 m_target.GetProcessSP()->CalculateExecutionContext(exe_ctx); 66 CaptureWatchedValue (exe_ctx); 67 } 68 m_being_created = false; 69} 70 71Watchpoint::~Watchpoint() 72{ 73} 74 75// This function is used when "baton" doesn't need to be freed 76void 77Watchpoint::SetCallback (WatchpointHitCallback callback, void *baton, bool is_synchronous) 78{ 79 // The default "Baton" class will keep a copy of "baton" and won't free 80 // or delete it when it goes goes out of scope. 81 m_options.SetCallback(callback, BatonSP (new Baton(baton)), is_synchronous); 82 83 SendWatchpointChangedEvent (eWatchpointEventTypeCommandChanged); 84} 85 86// This function is used when a baton needs to be freed and therefore is 87// contained in a "Baton" subclass. 88void 89Watchpoint::SetCallback (WatchpointHitCallback callback, const BatonSP &callback_baton_sp, bool is_synchronous) 90{ 91 m_options.SetCallback(callback, callback_baton_sp, is_synchronous); 92 SendWatchpointChangedEvent (eWatchpointEventTypeCommandChanged); 93} 94 95void 96Watchpoint::ClearCallback () 97{ 98 m_options.ClearCallback (); 99 SendWatchpointChangedEvent (eWatchpointEventTypeCommandChanged); 100} 101 102void 103Watchpoint::SetDeclInfo (const std::string &str) 104{ 105 m_decl_str = str; 106 return; 107} 108 109std::string 110Watchpoint::GetWatchSpec() 111{ 112 return m_watch_spec_str; 113} 114 115void 116Watchpoint::SetWatchSpec (const std::string &str) 117{ 118 m_watch_spec_str = str; 119 return; 120} 121 122// Override default impl of StoppointLocation::IsHardware() since m_is_hardware 123// member field is more accurate. 124bool 125Watchpoint::IsHardware () const 126{ 127 return m_is_hardware; 128} 129 130bool 131Watchpoint::IsWatchVariable() const 132{ 133 return m_is_watch_variable; 134} 135 136void 137Watchpoint::SetWatchVariable(bool val) 138{ 139 m_is_watch_variable = val; 140} 141 142bool 143Watchpoint::CaptureWatchedValue (const ExecutionContext &exe_ctx) 144{ 145 ConstString watch_name("$__lldb__watch_value"); 146 m_old_value_sp = m_new_value_sp; 147 Address watch_address(GetLoadAddress()); 148 if (!m_type.IsValid()) 149 { 150 // Don't know how to report new & old values, since we couldn't make a scalar type for this watchpoint. 151 // This works around an assert in ValueObjectMemory::Create. 152 // FIXME: This should not happen, but if it does in some case we care about, 153 // we can go grab the value raw and print it as unsigned. 154 return false; 155 } 156 m_new_value_sp = ValueObjectMemory::Create (exe_ctx.GetBestExecutionContextScope(), watch_name.AsCString(), watch_address, m_type); 157 m_new_value_sp = m_new_value_sp->CreateConstantValue(watch_name); 158 if (m_new_value_sp && m_new_value_sp->GetError().Success()) 159 return true; 160 else 161 return false; 162} 163 164void 165Watchpoint::IncrementFalseAlarmsAndReviseHitCount() 166{ 167 ++m_false_alarms; 168 if (m_false_alarms) 169 { 170 if (m_hit_count >= m_false_alarms) 171 { 172 m_hit_count -= m_false_alarms; 173 m_false_alarms = 0; 174 } 175 else 176 { 177 m_false_alarms -= m_hit_count; 178 m_hit_count = 0; 179 } 180 } 181} 182 183// RETURNS - true if we should stop at this breakpoint, false if we 184// should continue. 185 186bool 187Watchpoint::ShouldStop (StoppointCallbackContext *context) 188{ 189 IncrementHitCount(); 190 191 if (!IsEnabled()) 192 return false; 193 194 if (GetHitCount() <= GetIgnoreCount()) 195 return false; 196 197 return true; 198} 199 200void 201Watchpoint::GetDescription (Stream *s, lldb::DescriptionLevel level) 202{ 203 DumpWithLevel(s, level); 204 return; 205} 206 207void 208Watchpoint::Dump(Stream *s) const 209{ 210 DumpWithLevel(s, lldb::eDescriptionLevelBrief); 211} 212 213// If prefix is NULL, we display the watch id and ignore the prefix altogether. 214void 215Watchpoint::DumpSnapshots(Stream *s, const char *prefix) const 216{ 217 if (!prefix) 218 { 219 s->Printf("\nWatchpoint %u hit:", GetID()); 220 prefix = ""; 221 } 222 223 if (m_old_value_sp) 224 { 225 s->Printf("\n%sold value: %s", prefix, m_old_value_sp->GetValueAsCString()); 226 } 227 if (m_new_value_sp) 228 { 229 s->Printf("\n%snew value: %s", prefix, m_new_value_sp->GetValueAsCString()); 230 } 231} 232 233void 234Watchpoint::DumpWithLevel(Stream *s, lldb::DescriptionLevel description_level) const 235{ 236 if (s == NULL) 237 return; 238 239 assert(description_level >= lldb::eDescriptionLevelBrief && 240 description_level <= lldb::eDescriptionLevelVerbose); 241 242 s->Printf("Watchpoint %u: addr = 0x%8.8" PRIx64 " size = %u state = %s type = %s%s", 243 GetID(), 244 GetLoadAddress(), 245 m_byte_size, 246 IsEnabled() ? "enabled" : "disabled", 247 m_watch_read ? "r" : "", 248 m_watch_write ? "w" : ""); 249 250 if (description_level >= lldb::eDescriptionLevelFull) { 251 if (!m_decl_str.empty()) 252 s->Printf("\n declare @ '%s'", m_decl_str.c_str()); 253 if (!m_watch_spec_str.empty()) 254 s->Printf("\n watchpoint spec = '%s'", m_watch_spec_str.c_str()); 255 256 // Dump the snapshots we have taken. 257 DumpSnapshots(s, " "); 258 259 if (GetConditionText()) 260 s->Printf("\n condition = '%s'", GetConditionText()); 261 m_options.GetCallbackDescription(s, description_level); 262 } 263 264 if (description_level >= lldb::eDescriptionLevelVerbose) 265 { 266 s->Printf("\n hw_index = %i hit_count = %-4u ignore_count = %-4u", 267 GetHardwareIndex(), 268 GetHitCount(), 269 GetIgnoreCount()); 270 } 271} 272 273bool 274Watchpoint::IsEnabled() const 275{ 276 return m_enabled; 277} 278 279// Within StopInfo.cpp, we purposely turn on the ephemeral mode right before temporarily disable the watchpoint 280// in order to perform possible watchpoint actions without triggering further watchpoint events. 281// After the temporary disabled watchpoint is enabled, we then turn off the ephemeral mode. 282 283void 284Watchpoint::TurnOnEphemeralMode() 285{ 286 m_is_ephemeral = true; 287} 288 289void 290Watchpoint::TurnOffEphemeralMode() 291{ 292 m_is_ephemeral = false; 293 // Leaving ephemeral mode, reset the m_disabled_count! 294 m_disabled_count = 0; 295} 296 297bool 298Watchpoint::IsDisabledDuringEphemeralMode() 299{ 300 return m_disabled_count > 1; 301} 302 303void 304Watchpoint::SetEnabled(bool enabled, bool notify) 305{ 306 if (!enabled) 307 { 308 if (!m_is_ephemeral) 309 SetHardwareIndex(LLDB_INVALID_INDEX32); 310 else 311 ++m_disabled_count; 312 313 // Don't clear the snapshots for now. 314 // Within StopInfo.cpp, we purposely do disable/enable watchpoint while performing watchpoint actions. 315 } 316 bool changed = enabled != m_enabled; 317 m_enabled = enabled; 318 if (notify && !m_is_ephemeral && changed) 319 SendWatchpointChangedEvent (enabled ? eWatchpointEventTypeEnabled : eWatchpointEventTypeDisabled); 320} 321 322void 323Watchpoint::SetWatchpointType (uint32_t type, bool notify) 324{ 325 int old_watch_read = m_watch_read; 326 int old_watch_write = m_watch_write; 327 m_watch_read = (type & LLDB_WATCH_TYPE_READ) != 0; 328 m_watch_write = (type & LLDB_WATCH_TYPE_WRITE) != 0; 329 if (notify && (old_watch_read != m_watch_read || old_watch_write != m_watch_write)) 330 SendWatchpointChangedEvent (eWatchpointEventTypeTypeChanged); 331} 332 333bool 334Watchpoint::WatchpointRead () const 335{ 336 return m_watch_read != 0; 337} 338bool 339Watchpoint::WatchpointWrite () const 340{ 341 return m_watch_write != 0; 342} 343uint32_t 344Watchpoint::GetIgnoreCount () const 345{ 346 return m_ignore_count; 347} 348 349void 350Watchpoint::SetIgnoreCount (uint32_t n) 351{ 352 bool changed = m_ignore_count != n; 353 m_ignore_count = n; 354 if (changed) 355 SendWatchpointChangedEvent (eWatchpointEventTypeIgnoreChanged); 356} 357 358bool 359Watchpoint::InvokeCallback (StoppointCallbackContext *context) 360{ 361 return m_options.InvokeCallback (context, GetID()); 362} 363 364void 365Watchpoint::SetCondition (const char *condition) 366{ 367 if (condition == NULL || condition[0] == '\0') 368 { 369 if (m_condition_ap.get()) 370 m_condition_ap.reset(); 371 } 372 else 373 { 374 // Pass NULL for expr_prefix (no translation-unit level definitions). 375 m_condition_ap.reset(new ClangUserExpression (condition, NULL, lldb::eLanguageTypeUnknown, ClangUserExpression::eResultTypeAny)); 376 } 377 SendWatchpointChangedEvent (eWatchpointEventTypeConditionChanged); 378} 379 380const char * 381Watchpoint::GetConditionText () const 382{ 383 if (m_condition_ap.get()) 384 return m_condition_ap->GetUserText(); 385 else 386 return NULL; 387} 388 389void 390Watchpoint::SendWatchpointChangedEvent (lldb::WatchpointEventType eventKind) 391{ 392 if (!m_being_created 393 && GetTarget().EventTypeHasListeners(Target::eBroadcastBitWatchpointChanged)) 394 { 395 WatchpointEventData *data = new Watchpoint::WatchpointEventData (eventKind, shared_from_this()); 396 GetTarget().BroadcastEvent (Target::eBroadcastBitWatchpointChanged, data); 397 } 398} 399 400void 401Watchpoint::SendWatchpointChangedEvent (WatchpointEventData *data) 402{ 403 404 if (data == NULL) 405 return; 406 407 if (!m_being_created 408 && GetTarget().EventTypeHasListeners(Target::eBroadcastBitWatchpointChanged)) 409 GetTarget().BroadcastEvent (Target::eBroadcastBitWatchpointChanged, data); 410 else 411 delete data; 412} 413 414Watchpoint::WatchpointEventData::WatchpointEventData (WatchpointEventType sub_type, 415 const WatchpointSP &new_watchpoint_sp) : 416 EventData (), 417 m_watchpoint_event (sub_type), 418 m_new_watchpoint_sp (new_watchpoint_sp) 419{ 420} 421 422Watchpoint::WatchpointEventData::~WatchpointEventData () 423{ 424} 425 426const ConstString & 427Watchpoint::WatchpointEventData::GetFlavorString () 428{ 429 static ConstString g_flavor ("Watchpoint::WatchpointEventData"); 430 return g_flavor; 431} 432 433const ConstString & 434Watchpoint::WatchpointEventData::GetFlavor () const 435{ 436 return WatchpointEventData::GetFlavorString (); 437} 438 439 440WatchpointSP & 441Watchpoint::WatchpointEventData::GetWatchpoint () 442{ 443 return m_new_watchpoint_sp; 444} 445 446WatchpointEventType 447Watchpoint::WatchpointEventData::GetWatchpointEventType () const 448{ 449 return m_watchpoint_event; 450} 451 452void 453Watchpoint::WatchpointEventData::Dump (Stream *s) const 454{ 455} 456 457const Watchpoint::WatchpointEventData * 458Watchpoint::WatchpointEventData::GetEventDataFromEvent (const Event *event) 459{ 460 if (event) 461 { 462 const EventData *event_data = event->GetData(); 463 if (event_data && event_data->GetFlavor() == WatchpointEventData::GetFlavorString()) 464 return static_cast <const WatchpointEventData *> (event->GetData()); 465 } 466 return NULL; 467} 468 469WatchpointEventType 470Watchpoint::WatchpointEventData::GetWatchpointEventTypeFromEvent (const EventSP &event_sp) 471{ 472 const WatchpointEventData *data = GetEventDataFromEvent (event_sp.get()); 473 474 if (data == NULL) 475 return eWatchpointEventTypeInvalidType; 476 else 477 return data->GetWatchpointEventType(); 478} 479 480WatchpointSP 481Watchpoint::WatchpointEventData::GetWatchpointFromEvent (const EventSP &event_sp) 482{ 483 WatchpointSP wp_sp; 484 485 const WatchpointEventData *data = GetEventDataFromEvent (event_sp.get()); 486 if (data) 487 wp_sp = data->m_new_watchpoint_sp; 488 489 return wp_sp; 490} 491