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