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