1 //===-- ThreadPlanStepOut.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/Target/ThreadPlanStepOut.h" 11 12 // C Includes 13 // C++ Includes 14 // Other libraries and framework includes 15 // Project includes 16 #include "lldb/Breakpoint/Breakpoint.h" 17 #include "lldb/lldb-private-log.h" 18 #include "lldb/Core/Log.h" 19 #include "lldb/Core/Value.h" 20 #include "lldb/Core/ValueObjectConstResult.h" 21 #include "lldb/Symbol/Block.h" 22 #include "lldb/Symbol/Function.h" 23 #include "lldb/Symbol/Type.h" 24 #include "lldb/Target/ABI.h" 25 #include "lldb/Target/Process.h" 26 #include "lldb/Target/RegisterContext.h" 27 #include "lldb/Target/StopInfo.h" 28 #include "lldb/Target/Target.h" 29 #include "lldb/Target/ThreadPlanStepOverRange.h" 30 #include "lldb/Target/ThreadPlanStepThrough.h" 31 32 using namespace lldb; 33 using namespace lldb_private; 34 35 uint32_t ThreadPlanStepOut::s_default_flag_values = 0; 36 37 //---------------------------------------------------------------------- 38 // ThreadPlanStepOut: Step out of the current frame 39 //---------------------------------------------------------------------- 40 ThreadPlanStepOut::ThreadPlanStepOut 41 ( 42 Thread &thread, 43 SymbolContext *context, 44 bool first_insn, 45 bool stop_others, 46 Vote stop_vote, 47 Vote run_vote, 48 uint32_t frame_idx, 49 LazyBool step_out_avoids_code_without_debug_info 50 ) : 51 ThreadPlan (ThreadPlan::eKindStepOut, "Step out", thread, stop_vote, run_vote), 52 ThreadPlanShouldStopHere (this), 53 m_step_from_insn (LLDB_INVALID_ADDRESS), 54 m_return_bp_id (LLDB_INVALID_BREAK_ID), 55 m_return_addr (LLDB_INVALID_ADDRESS), 56 m_stop_others (stop_others), 57 m_immediate_step_from_function(NULL) 58 { 59 SetFlagsToDefault(); 60 SetupAvoidNoDebug(step_out_avoids_code_without_debug_info); 61 62 m_step_from_insn = m_thread.GetRegisterContext()->GetPC(0); 63 64 StackFrameSP return_frame_sp (m_thread.GetStackFrameAtIndex(frame_idx + 1)); 65 StackFrameSP immediate_return_from_sp (m_thread.GetStackFrameAtIndex (frame_idx)); 66 67 if (!return_frame_sp || !immediate_return_from_sp) 68 return; // we can't do anything here. ValidatePlan() will return false. 69 70 m_step_out_to_id = return_frame_sp->GetStackID(); 71 m_immediate_step_from_id = immediate_return_from_sp->GetStackID(); 72 73 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 74 75 // If the frame directly below the one we are returning to is inlined, we have to be 76 // a little more careful. It is non-trivial to determine the real "return code address" for 77 // an inlined frame, so we have to work our way to that frame and then step out. 78 if (immediate_return_from_sp && immediate_return_from_sp->IsInlined()) 79 { 80 if (frame_idx > 0) 81 { 82 // First queue a plan that gets us to this inlined frame, and when we get there we'll queue a second 83 // plan that walks us out of this frame. 84 m_step_out_to_inline_plan_sp.reset (new ThreadPlanStepOut(m_thread, 85 NULL, 86 false, 87 stop_others, 88 eVoteNoOpinion, 89 eVoteNoOpinion, 90 frame_idx - 1, 91 eLazyBoolNo)); 92 static_cast<ThreadPlanStepOut *>(m_step_out_to_inline_plan_sp.get())->SetShouldStopHereCallbacks(nullptr, nullptr); 93 m_step_out_to_inline_plan_sp->SetPrivate(true); 94 } 95 else 96 { 97 // If we're already at the inlined frame we're stepping through, then just do that now. 98 QueueInlinedStepPlan(false); 99 } 100 101 } 102 else if (return_frame_sp) 103 { 104 // Find the return address and set a breakpoint there: 105 // FIXME - can we do this more securely if we know first_insn? 106 107 m_return_addr = return_frame_sp->GetFrameCodeAddress().GetLoadAddress(&m_thread.GetProcess()->GetTarget()); 108 109 if (m_return_addr == LLDB_INVALID_ADDRESS) 110 return; 111 112 Breakpoint *return_bp = m_thread.CalculateTarget()->CreateBreakpoint (m_return_addr, true, false).get(); 113 if (return_bp != NULL) 114 { 115 return_bp->SetThreadID(m_thread.GetID()); 116 m_return_bp_id = return_bp->GetID(); 117 return_bp->SetBreakpointKind ("step-out"); 118 } 119 120 if (immediate_return_from_sp) 121 { 122 const SymbolContext &sc = immediate_return_from_sp->GetSymbolContext(eSymbolContextFunction); 123 if (sc.function) 124 { 125 m_immediate_step_from_function = sc.function; 126 } 127 } 128 } 129 130 } 131 132 void 133 ThreadPlanStepOut::SetupAvoidNoDebug(LazyBool step_out_avoids_code_without_debug_info) 134 { 135 bool avoid_nodebug = true; 136 switch (step_out_avoids_code_without_debug_info) 137 { 138 case eLazyBoolYes: 139 avoid_nodebug = true; 140 break; 141 case eLazyBoolNo: 142 avoid_nodebug = false; 143 break; 144 case eLazyBoolCalculate: 145 avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug(); 146 break; 147 } 148 if (avoid_nodebug) 149 GetFlags().Set (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 150 else 151 GetFlags().Clear (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 152 } 153 154 void 155 ThreadPlanStepOut::DidPush() 156 { 157 if (m_step_out_to_inline_plan_sp) 158 m_thread.QueueThreadPlan(m_step_out_to_inline_plan_sp, false); 159 else if (m_step_through_inline_plan_sp) 160 m_thread.QueueThreadPlan(m_step_through_inline_plan_sp, false); 161 } 162 163 ThreadPlanStepOut::~ThreadPlanStepOut () 164 { 165 if (m_return_bp_id != LLDB_INVALID_BREAK_ID) 166 m_thread.CalculateTarget()->RemoveBreakpointByID(m_return_bp_id); 167 } 168 169 void 170 ThreadPlanStepOut::GetDescription (Stream *s, lldb::DescriptionLevel level) 171 { 172 if (level == lldb::eDescriptionLevelBrief) 173 s->Printf ("step out"); 174 else 175 { 176 if (m_step_out_to_inline_plan_sp) 177 s->Printf ("Stepping out to inlined frame so we can walk through it."); 178 else if (m_step_through_inline_plan_sp) 179 s->Printf ("Stepping out by stepping through inlined function."); 180 else 181 { 182 s->Printf ("Stepping out from "); 183 Address tmp_address; 184 if (tmp_address.SetLoadAddress (m_step_from_insn, &GetTarget())) 185 { 186 tmp_address.Dump(s, &GetThread(), Address::DumpStyleResolvedDescription, Address::DumpStyleLoadAddress); 187 } 188 else 189 { 190 s->Printf ("address 0x%" PRIx64 "", (uint64_t)m_step_from_insn); 191 } 192 193 // FIXME: find some useful way to present the m_return_id, since there may be multiple copies of the 194 // same function on the stack. 195 196 s->Printf ("returning to frame at "); 197 if (tmp_address.SetLoadAddress (m_return_addr, &GetTarget())) 198 { 199 tmp_address.Dump(s, &GetThread(), Address::DumpStyleResolvedDescription, Address::DumpStyleLoadAddress); 200 } 201 else 202 { 203 s->Printf ("address 0x%" PRIx64 "", (uint64_t)m_return_addr); 204 } 205 206 if (level == eDescriptionLevelVerbose) 207 s->Printf(" using breakpoint site %d", m_return_bp_id); 208 } 209 } 210 } 211 212 bool 213 ThreadPlanStepOut::ValidatePlan (Stream *error) 214 { 215 if (m_step_out_to_inline_plan_sp) 216 return m_step_out_to_inline_plan_sp->ValidatePlan (error); 217 else if (m_step_through_inline_plan_sp) 218 return m_step_through_inline_plan_sp->ValidatePlan (error); 219 else if (m_return_bp_id == LLDB_INVALID_BREAK_ID) 220 { 221 if (error) 222 error->PutCString("Could not create return address breakpoint."); 223 return false; 224 } 225 else 226 return true; 227 } 228 229 bool 230 ThreadPlanStepOut::DoPlanExplainsStop (Event *event_ptr) 231 { 232 // If the step out plan is done, then we just need to step through the inlined frame. 233 if (m_step_out_to_inline_plan_sp) 234 { 235 if (m_step_out_to_inline_plan_sp->MischiefManaged()) 236 return true; 237 else 238 return false; 239 } 240 else if (m_step_through_inline_plan_sp) 241 { 242 if (m_step_through_inline_plan_sp->MischiefManaged()) 243 { 244 CalculateReturnValue(); 245 SetPlanComplete(); 246 return true; 247 } 248 else 249 return false; 250 } 251 else if (m_step_out_further_plan_sp) 252 { 253 if (m_step_out_further_plan_sp->MischiefManaged()) 254 return true; 255 else 256 return false; 257 } 258 259 // We don't explain signals or breakpoints (breakpoints that handle stepping in or 260 // out will be handled by a child plan. 261 262 StopInfoSP stop_info_sp = GetPrivateStopInfo (); 263 if (stop_info_sp) 264 { 265 StopReason reason = stop_info_sp->GetStopReason(); 266 switch (reason) 267 { 268 case eStopReasonBreakpoint: 269 { 270 // If this is OUR breakpoint, we're fine, otherwise we don't know why this happened... 271 BreakpointSiteSP site_sp (m_thread.GetProcess()->GetBreakpointSiteList().FindByID (stop_info_sp->GetValue())); 272 if (site_sp && site_sp->IsBreakpointAtThisSite (m_return_bp_id)) 273 { 274 bool done; 275 276 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 277 278 if (m_step_out_to_id == frame_zero_id) 279 done = true; 280 else if (m_step_out_to_id < frame_zero_id) 281 { 282 // Either we stepped past the breakpoint, or the stack ID calculation 283 // was incorrect and we should probably stop. 284 done = true; 285 } 286 else 287 { 288 if (m_immediate_step_from_id < frame_zero_id) 289 done = true; 290 else 291 done = false; 292 } 293 294 if (done) 295 { 296 if (InvokeShouldStopHereCallback (eFrameCompareOlder)) 297 { 298 CalculateReturnValue(); 299 SetPlanComplete(); 300 } 301 } 302 303 // If there was only one owner, then we're done. But if we also hit some 304 // user breakpoint on our way out, we should mark ourselves as done, but 305 // also not claim to explain the stop, since it is more important to report 306 // the user breakpoint than the step out completion. 307 308 if (site_sp->GetNumberOfOwners() == 1) 309 return true; 310 311 } 312 return false; 313 } 314 case eStopReasonWatchpoint: 315 case eStopReasonSignal: 316 case eStopReasonException: 317 case eStopReasonExec: 318 case eStopReasonThreadExiting: 319 return false; 320 321 default: 322 return true; 323 } 324 } 325 return true; 326 } 327 328 bool 329 ThreadPlanStepOut::ShouldStop (Event *event_ptr) 330 { 331 if (IsPlanComplete()) 332 return true; 333 334 bool done = false; 335 if (m_step_out_to_inline_plan_sp) 336 { 337 if (m_step_out_to_inline_plan_sp->MischiefManaged()) 338 { 339 // Now step through the inlined stack we are in: 340 if (QueueInlinedStepPlan(true)) 341 { 342 // If we can't queue a plan to do this, then just call ourselves done. 343 m_step_out_to_inline_plan_sp.reset(); 344 SetPlanComplete (false); 345 return true; 346 } 347 else 348 done = true; 349 } 350 else 351 return m_step_out_to_inline_plan_sp->ShouldStop(event_ptr); 352 } 353 else if (m_step_through_inline_plan_sp) 354 { 355 if (m_step_through_inline_plan_sp->MischiefManaged()) 356 done = true; 357 else 358 return m_step_through_inline_plan_sp->ShouldStop(event_ptr); 359 } 360 else if (m_step_out_further_plan_sp) 361 { 362 if (m_step_out_further_plan_sp->MischiefManaged()) 363 m_step_out_further_plan_sp.reset(); 364 else 365 return m_step_out_further_plan_sp->ShouldStop(event_ptr); 366 } 367 368 if (!done) 369 { 370 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 371 if (frame_zero_id < m_step_out_to_id) 372 done = false; 373 else 374 done = true; 375 } 376 377 // The normal step out computations think we are done, so all we need to do is consult the ShouldStopHere, 378 // and we are done. 379 380 if (done) 381 { 382 if (InvokeShouldStopHereCallback(eFrameCompareOlder)) 383 { 384 CalculateReturnValue(); 385 SetPlanComplete(); 386 } 387 else 388 { 389 m_step_out_further_plan_sp = QueueStepOutFromHerePlan(m_flags, eFrameCompareOlder); 390 done = false; 391 } 392 } 393 394 return done; 395 } 396 397 bool 398 ThreadPlanStepOut::StopOthers () 399 { 400 return m_stop_others; 401 } 402 403 StateType 404 ThreadPlanStepOut::GetPlanRunState () 405 { 406 return eStateRunning; 407 } 408 409 bool 410 ThreadPlanStepOut::DoWillResume (StateType resume_state, bool current_plan) 411 { 412 if (m_step_out_to_inline_plan_sp || m_step_through_inline_plan_sp) 413 return true; 414 415 if (m_return_bp_id == LLDB_INVALID_BREAK_ID) 416 return false; 417 418 if (current_plan) 419 { 420 Breakpoint *return_bp = m_thread.CalculateTarget()->GetBreakpointByID(m_return_bp_id).get(); 421 if (return_bp != NULL) 422 return_bp->SetEnabled (true); 423 } 424 return true; 425 } 426 427 bool 428 ThreadPlanStepOut::WillStop () 429 { 430 if (m_return_bp_id != LLDB_INVALID_BREAK_ID) 431 { 432 Breakpoint *return_bp = m_thread.CalculateTarget()->GetBreakpointByID(m_return_bp_id).get(); 433 if (return_bp != NULL) 434 return_bp->SetEnabled (false); 435 } 436 437 return true; 438 } 439 440 bool 441 ThreadPlanStepOut::MischiefManaged () 442 { 443 if (IsPlanComplete()) 444 { 445 // Did I reach my breakpoint? If so I'm done. 446 // 447 // I also check the stack depth, since if we've blown past the breakpoint for some 448 // reason and we're now stopping for some other reason altogether, then we're done 449 // with this step out operation. 450 451 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 452 if (log) 453 log->Printf("Completed step out plan."); 454 if (m_return_bp_id != LLDB_INVALID_BREAK_ID) 455 { 456 m_thread.CalculateTarget()->RemoveBreakpointByID (m_return_bp_id); 457 m_return_bp_id = LLDB_INVALID_BREAK_ID; 458 } 459 460 ThreadPlan::MischiefManaged (); 461 return true; 462 } 463 else 464 { 465 return false; 466 } 467 } 468 469 bool 470 ThreadPlanStepOut::QueueInlinedStepPlan (bool queue_now) 471 { 472 // Now figure out the range of this inlined block, and set up a "step through range" 473 // plan for that. If we've been provided with a context, then use the block in that 474 // context. 475 StackFrameSP immediate_return_from_sp (m_thread.GetStackFrameAtIndex (0)); 476 if (!immediate_return_from_sp) 477 return false; 478 479 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 480 if (log) 481 { 482 StreamString s; 483 immediate_return_from_sp->Dump(&s, true, false); 484 log->Printf("Queuing inlined frame to step past: %s.", s.GetData()); 485 } 486 487 Block *from_block = immediate_return_from_sp->GetFrameBlock(); 488 if (from_block) 489 { 490 Block *inlined_block = from_block->GetContainingInlinedBlock(); 491 if (inlined_block) 492 { 493 size_t num_ranges = inlined_block->GetNumRanges(); 494 AddressRange inline_range; 495 if (inlined_block->GetRangeAtIndex(0, inline_range)) 496 { 497 SymbolContext inlined_sc; 498 inlined_block->CalculateSymbolContext(&inlined_sc); 499 inlined_sc.target_sp = GetTarget().shared_from_this(); 500 RunMode run_mode = m_stop_others ? lldb::eOnlyThisThread : lldb::eAllThreads; 501 const LazyBool avoid_no_debug = eLazyBoolNo; 502 503 m_step_through_inline_plan_sp.reset (new ThreadPlanStepOverRange(m_thread, 504 inline_range, 505 inlined_sc, 506 run_mode, 507 avoid_no_debug)); 508 ThreadPlanStepOverRange *step_through_inline_plan_ptr 509 = static_cast<ThreadPlanStepOverRange *>(m_step_through_inline_plan_sp.get()); 510 m_step_through_inline_plan_sp->SetPrivate(true); 511 512 step_through_inline_plan_ptr->SetOkayToDiscard(true); 513 StreamString errors; 514 if (!step_through_inline_plan_ptr->ValidatePlan(&errors)) 515 { 516 //FIXME: Log this failure. 517 delete step_through_inline_plan_ptr; 518 return false; 519 } 520 521 for (size_t i = 1; i < num_ranges; i++) 522 { 523 if (inlined_block->GetRangeAtIndex (i, inline_range)) 524 step_through_inline_plan_ptr->AddRange (inline_range); 525 } 526 527 if (queue_now) 528 m_thread.QueueThreadPlan (m_step_through_inline_plan_sp, false); 529 return true; 530 } 531 } 532 } 533 534 return false; 535 } 536 537 void 538 ThreadPlanStepOut::CalculateReturnValue () 539 { 540 if (m_return_valobj_sp) 541 return; 542 543 if (m_immediate_step_from_function != NULL) 544 { 545 ClangASTType return_clang_type = m_immediate_step_from_function->GetClangType().GetFunctionReturnType(); 546 if (return_clang_type) 547 { 548 lldb::ABISP abi_sp = m_thread.GetProcess()->GetABI(); 549 if (abi_sp) 550 m_return_valobj_sp = abi_sp->GetReturnValueObject(m_thread, return_clang_type); 551 } 552 } 553 } 554 555 bool 556 ThreadPlanStepOut::IsPlanStale() 557 { 558 // If we are still lower on the stack than the frame we are returning to, then 559 // there's something for us to do. Otherwise, we're stale. 560 561 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 562 if (frame_zero_id < m_step_out_to_id) 563 return false; 564 else 565 return true; 566 } 567