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 } 111 112 if (immediate_return_from_sp) 113 { 114 const SymbolContext &sc = immediate_return_from_sp->GetSymbolContext(eSymbolContextFunction); 115 if (sc.function) 116 { 117 m_immediate_step_from_function = sc.function; 118 } 119 } 120 } 121 122 } 123 124 void 125 ThreadPlanStepOut::DidPush() 126 { 127 if (m_step_out_plan_sp) 128 m_thread.QueueThreadPlan(m_step_out_plan_sp, false); 129 else if (m_step_through_inline_plan_sp) 130 m_thread.QueueThreadPlan(m_step_through_inline_plan_sp, false); 131 } 132 133 ThreadPlanStepOut::~ThreadPlanStepOut () 134 { 135 if (m_return_bp_id != LLDB_INVALID_BREAK_ID) 136 m_thread.CalculateTarget()->RemoveBreakpointByID(m_return_bp_id); 137 } 138 139 void 140 ThreadPlanStepOut::GetDescription (Stream *s, lldb::DescriptionLevel level) 141 { 142 if (level == lldb::eDescriptionLevelBrief) 143 s->Printf ("step out"); 144 else 145 { 146 if (m_step_out_plan_sp) 147 s->Printf ("Stepping out to inlined frame so we can walk through it."); 148 else if (m_step_through_inline_plan_sp) 149 s->Printf ("Stepping out by stepping through inlined function."); 150 else 151 s->Printf ("Stepping out from address 0x%" PRIx64 " to return address 0x%" PRIx64 " using breakpoint site %d", 152 (uint64_t)m_step_from_insn, 153 (uint64_t)m_return_addr, 154 m_return_bp_id); 155 } 156 } 157 158 bool 159 ThreadPlanStepOut::ValidatePlan (Stream *error) 160 { 161 if (m_step_out_plan_sp) 162 return m_step_out_plan_sp->ValidatePlan (error); 163 else if (m_step_through_inline_plan_sp) 164 return m_step_through_inline_plan_sp->ValidatePlan (error); 165 else if (m_return_bp_id == LLDB_INVALID_BREAK_ID) 166 { 167 if (error) 168 error->PutCString("Could not create return address breakpoint."); 169 return false; 170 } 171 else 172 return true; 173 } 174 175 bool 176 ThreadPlanStepOut::PlanExplainsStop () 177 { 178 // If one of our child plans just finished, then we do explain the stop. 179 if (m_step_out_plan_sp) 180 { 181 if (m_step_out_plan_sp->MischiefManaged()) 182 { 183 // If this one is done, then we are all done. 184 CalculateReturnValue(); 185 SetPlanComplete(); 186 return true; 187 } 188 else 189 return false; 190 } 191 else if (m_step_through_inline_plan_sp) 192 { 193 if (m_step_through_inline_plan_sp->MischiefManaged()) 194 return true; 195 else 196 return false; 197 } 198 199 // We don't explain signals or breakpoints (breakpoints that handle stepping in or 200 // out will be handled by a child plan. 201 202 StopInfoSP stop_info_sp = GetPrivateStopReason(); 203 if (stop_info_sp) 204 { 205 StopReason reason = stop_info_sp->GetStopReason(); 206 switch (reason) 207 { 208 case eStopReasonBreakpoint: 209 { 210 // If this is OUR breakpoint, we're fine, otherwise we don't know why this happened... 211 BreakpointSiteSP site_sp (m_thread.GetProcess()->GetBreakpointSiteList().FindByID (stop_info_sp->GetValue())); 212 if (site_sp && site_sp->IsBreakpointAtThisSite (m_return_bp_id)) 213 { 214 bool done; 215 216 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 217 218 if (m_step_out_to_id == frame_zero_id) 219 done = true; 220 else if (m_step_out_to_id < frame_zero_id) 221 { 222 // Either we stepped past the breakpoint, or the stack ID calculation 223 // was incorrect and we should probably stop. 224 done = true; 225 } 226 else 227 { 228 if (m_immediate_step_from_id < frame_zero_id) 229 done = true; 230 else 231 done = false; 232 } 233 234 if (done) 235 { 236 CalculateReturnValue(); 237 SetPlanComplete(); 238 } 239 240 // If there was only one owner, then we're done. But if we also hit some 241 // user breakpoint on our way out, we should mark ourselves as done, but 242 // also not claim to explain the stop, since it is more important to report 243 // the user breakpoint than the step out completion. 244 245 if (site_sp->GetNumberOfOwners() == 1) 246 return true; 247 248 } 249 return false; 250 } 251 case eStopReasonWatchpoint: 252 case eStopReasonSignal: 253 case eStopReasonException: 254 case eStopReasonExec: 255 case eStopReasonThreadExiting: 256 return false; 257 258 default: 259 return true; 260 } 261 } 262 return true; 263 } 264 265 bool 266 ThreadPlanStepOut::ShouldStop (Event *event_ptr) 267 { 268 if (IsPlanComplete()) 269 return true; 270 271 bool done; 272 273 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 274 if (frame_zero_id < m_step_out_to_id) 275 done = false; 276 else 277 done = true; 278 279 if (done) 280 { 281 CalculateReturnValue(); 282 SetPlanComplete(); 283 return true; 284 } 285 else 286 { 287 if (m_step_out_plan_sp) 288 { 289 if (m_step_out_plan_sp->MischiefManaged()) 290 { 291 // Now step through the inlined stack we are in: 292 if (QueueInlinedStepPlan(true)) 293 { 294 return false; 295 } 296 else 297 { 298 CalculateReturnValue(); 299 SetPlanComplete (); 300 return true; 301 } 302 } 303 else 304 return m_step_out_plan_sp->ShouldStop(event_ptr); 305 } 306 else if (m_step_through_inline_plan_sp) 307 { 308 if (m_step_through_inline_plan_sp->MischiefManaged()) 309 { 310 // We don't calculate the return value here because we don't know how to. 311 // But in case we had a return value sitting around from our process in 312 // getting here, let's clear it out. 313 m_return_valobj_sp.reset(); 314 SetPlanComplete(); 315 return true; 316 } 317 else 318 return m_step_through_inline_plan_sp->ShouldStop(event_ptr); 319 } 320 else 321 return false; 322 } 323 } 324 325 bool 326 ThreadPlanStepOut::StopOthers () 327 { 328 return m_stop_others; 329 } 330 331 StateType 332 ThreadPlanStepOut::GetPlanRunState () 333 { 334 return eStateRunning; 335 } 336 337 bool 338 ThreadPlanStepOut::WillResume (StateType resume_state, bool current_plan) 339 { 340 ThreadPlan::WillResume (resume_state, current_plan); 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 LogSP 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 LogSP 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 Type *return_type = m_immediate_step_from_function->GetType(); 468 lldb::clang_type_t return_clang_type = m_immediate_step_from_function->GetReturnClangType(); 469 if (return_type && return_clang_type) 470 { 471 ClangASTType ast_type (return_type->GetClangAST(), return_clang_type); 472 473 lldb::ABISP abi_sp = m_thread.GetProcess()->GetABI(); 474 if (abi_sp) 475 { 476 m_return_valobj_sp = abi_sp->GetReturnValueObject(m_thread, ast_type); 477 } 478 } 479 } 480 } 481 482 bool 483 ThreadPlanStepOut::IsPlanStale() 484 { 485 // If we are still lower on the stack than the frame we are returning to, then 486 // there's something for us to do. Otherwise, we're stale. 487 488 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 489 if (frame_zero_id < m_step_out_to_id) 490 return false; 491 else 492 return true; 493 } 494 495