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/Target/Process.h" 22 #include "lldb/Target/RegisterContext.h" 23 #include "lldb/Target/StopInfo.h" 24 #include "lldb/Target/Target.h" 25 #include "lldb/Target/ThreadPlanStepOverRange.h" 26 27 using namespace lldb; 28 using namespace lldb_private; 29 30 //---------------------------------------------------------------------- 31 // ThreadPlanStepOut: Step out of the current frame 32 //---------------------------------------------------------------------- 33 ThreadPlanStepOut::ThreadPlanStepOut 34 ( 35 Thread &thread, 36 SymbolContext *context, 37 bool first_insn, 38 bool stop_others, 39 Vote stop_vote, 40 Vote run_vote, 41 uint32_t frame_idx 42 ) : 43 ThreadPlan (ThreadPlan::eKindStepOut, "Step out", thread, stop_vote, run_vote), 44 m_step_from_context (context), 45 m_step_from_insn (LLDB_INVALID_ADDRESS), 46 m_return_bp_id (LLDB_INVALID_BREAK_ID), 47 m_return_addr (LLDB_INVALID_ADDRESS), 48 m_first_insn (first_insn), 49 m_stop_others (stop_others), 50 m_step_through_inline_plan_sp(), 51 m_step_out_plan_sp (), 52 m_immediate_step_from_function(NULL) 53 54 { 55 m_step_from_insn = m_thread.GetRegisterContext()->GetPC(0); 56 57 StackFrameSP return_frame_sp (m_thread.GetStackFrameAtIndex(frame_idx + 1)); 58 StackFrameSP immediate_return_from_sp (m_thread.GetStackFrameAtIndex (frame_idx)); 59 60 m_step_out_to_id = return_frame_sp->GetStackID(); 61 m_immediate_step_from_id = immediate_return_from_sp->GetStackID(); 62 63 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 64 65 // If the frame directly below the one we are returning to is inlined, we have to be 66 // a little more careful. It is non-trivial to determine the real "return code address" for 67 // an inlined frame, so we have to work our way to that frame and then step out. 68 if (immediate_return_from_sp && immediate_return_from_sp->IsInlined()) 69 { 70 if (frame_idx > 0) 71 { 72 // First queue a plan that gets us to this inlined frame, and when we get there we'll queue a second 73 // plan that walks us out of this frame. 74 m_step_out_plan_sp.reset (new ThreadPlanStepOut(m_thread, 75 NULL, 76 false, 77 stop_others, 78 eVoteNoOpinion, 79 eVoteNoOpinion, 80 frame_idx - 1)); 81 m_step_out_plan_sp->SetOkayToDiscard(true); 82 } 83 else 84 { 85 // If we're already at the inlined frame we're stepping through, then just do that now. 86 QueueInlinedStepPlan(false); 87 } 88 89 } 90 else if (return_frame_sp) 91 { 92 // Find the return address and set a breakpoint there: 93 // FIXME - can we do this more securely if we know first_insn? 94 95 m_return_addr = return_frame_sp->GetFrameCodeAddress().GetLoadAddress(&m_thread.GetProcess()->GetTarget()); 96 Breakpoint *return_bp = m_thread.CalculateTarget()->CreateBreakpoint (m_return_addr, true).get(); 97 if (return_bp != NULL) 98 { 99 return_bp->SetThreadID(m_thread.GetID()); 100 m_return_bp_id = return_bp->GetID(); 101 } 102 103 if (immediate_return_from_sp) 104 { 105 const SymbolContext &sc = immediate_return_from_sp->GetSymbolContext(eSymbolContextFunction); 106 if (sc.function) 107 { 108 m_immediate_step_from_function = sc.function; 109 } 110 } 111 } 112 113 } 114 115 void 116 ThreadPlanStepOut::DidPush() 117 { 118 if (m_step_out_plan_sp) 119 m_thread.QueueThreadPlan(m_step_out_plan_sp, false); 120 else if (m_step_through_inline_plan_sp) 121 m_thread.QueueThreadPlan(m_step_through_inline_plan_sp, false); 122 } 123 124 ThreadPlanStepOut::~ThreadPlanStepOut () 125 { 126 if (m_return_bp_id != LLDB_INVALID_BREAK_ID) 127 m_thread.CalculateTarget()->RemoveBreakpointByID(m_return_bp_id); 128 } 129 130 void 131 ThreadPlanStepOut::GetDescription (Stream *s, lldb::DescriptionLevel level) 132 { 133 if (level == lldb::eDescriptionLevelBrief) 134 s->Printf ("step out"); 135 else 136 { 137 if (m_step_out_plan_sp) 138 s->Printf ("Stepping out to inlined frame so we can walk through it."); 139 else if (m_step_through_inline_plan_sp) 140 s->Printf ("Stepping out by stepping through inlined function."); 141 else 142 s->Printf ("Stepping out from address 0x%llx to return address 0x%llx using breakpoint site %d", 143 (uint64_t)m_step_from_insn, 144 (uint64_t)m_return_addr, 145 m_return_bp_id); 146 } 147 } 148 149 bool 150 ThreadPlanStepOut::ValidatePlan (Stream *error) 151 { 152 if (m_step_out_plan_sp) 153 return m_step_out_plan_sp->ValidatePlan (error); 154 else if (m_step_through_inline_plan_sp) 155 return m_step_through_inline_plan_sp->ValidatePlan (error); 156 else if (m_return_bp_id == LLDB_INVALID_BREAK_ID) 157 { 158 error->PutCString("Could not create return address breakpoint."); 159 return false; 160 } 161 else 162 return true; 163 } 164 165 bool 166 ThreadPlanStepOut::PlanExplainsStop () 167 { 168 // If one of our child plans just finished, then we do explain the stop. 169 if (m_step_out_plan_sp) 170 { 171 if (m_step_out_plan_sp->MischiefManaged()) 172 { 173 // If this one is done, then we are all done. 174 CalculateReturnValue(); 175 SetPlanComplete(); 176 return true; 177 } 178 else 179 return false; 180 } 181 else if (m_step_through_inline_plan_sp) 182 { 183 if (m_step_through_inline_plan_sp->MischiefManaged()) 184 return true; 185 else 186 return false; 187 } 188 189 // We don't explain signals or breakpoints (breakpoints that handle stepping in or 190 // out will be handled by a child plan. 191 192 StopInfoSP stop_info_sp = GetPrivateStopReason(); 193 if (stop_info_sp) 194 { 195 StopReason reason = stop_info_sp->GetStopReason(); 196 switch (reason) 197 { 198 case eStopReasonBreakpoint: 199 { 200 // If this is OUR breakpoint, we're fine, otherwise we don't know why this happened... 201 BreakpointSiteSP site_sp (m_thread.GetProcess()->GetBreakpointSiteList().FindByID (stop_info_sp->GetValue())); 202 if (site_sp && site_sp->IsBreakpointAtThisSite (m_return_bp_id)) 203 { 204 bool done; 205 206 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 207 208 if (m_step_out_to_id == frame_zero_id) 209 done = true; 210 else if (m_step_out_to_id < frame_zero_id) 211 { 212 // Either we stepped past the breakpoint, or the stack ID calculation 213 // was incorrect and we should probably stop. 214 done = true; 215 } 216 else 217 { 218 if (m_immediate_step_from_id < frame_zero_id) 219 done = true; 220 else 221 done = false; 222 } 223 224 if (done) 225 { 226 CalculateReturnValue(); 227 SetPlanComplete(); 228 } 229 230 // If there was only one owner, then we're done. But if we also hit some 231 // user breakpoint on our way out, we should mark ourselves as done, but 232 // also not claim to explain the stop, since it is more important to report 233 // the user breakpoint than the step out completion. 234 235 if (site_sp->GetNumberOfOwners() == 1) 236 return true; 237 238 } 239 return false; 240 } 241 case eStopReasonWatchpoint: 242 case eStopReasonSignal: 243 case eStopReasonException: 244 return false; 245 246 default: 247 return true; 248 } 249 } 250 return true; 251 } 252 253 bool 254 ThreadPlanStepOut::ShouldStop (Event *event_ptr) 255 { 256 if (IsPlanComplete()) 257 return true; 258 259 bool done; 260 261 StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID(); 262 if (frame_zero_id < m_step_out_to_id) 263 done = false; 264 else 265 done = true; 266 267 if (done) 268 { 269 CalculateReturnValue(); 270 SetPlanComplete(); 271 return true; 272 } 273 else 274 { 275 if (m_step_out_plan_sp) 276 { 277 if (m_step_out_plan_sp->MischiefManaged()) 278 { 279 // Now step through the inlined stack we are in: 280 if (QueueInlinedStepPlan(true)) 281 { 282 return false; 283 } 284 else 285 { 286 CalculateReturnValue(); 287 SetPlanComplete (); 288 return true; 289 } 290 } 291 else 292 return m_step_out_plan_sp->ShouldStop(event_ptr); 293 } 294 else if (m_step_through_inline_plan_sp) 295 { 296 if (m_step_through_inline_plan_sp->MischiefManaged()) 297 { 298 // We don't calculate the return value here because we don't know how to. 299 // But in case we had a return value sitting around from our process in 300 // getting here, let's clear it out. 301 m_return_valobj_sp.reset(); 302 SetPlanComplete(); 303 return true; 304 } 305 else 306 return m_step_through_inline_plan_sp->ShouldStop(event_ptr); 307 } 308 else 309 return false; 310 } 311 } 312 313 bool 314 ThreadPlanStepOut::StopOthers () 315 { 316 return m_stop_others; 317 } 318 319 StateType 320 ThreadPlanStepOut::GetPlanRunState () 321 { 322 return eStateRunning; 323 } 324 325 bool 326 ThreadPlanStepOut::WillResume (StateType resume_state, bool current_plan) 327 { 328 ThreadPlan::WillResume (resume_state, current_plan); 329 if (m_step_out_plan_sp || m_step_through_inline_plan_sp) 330 return true; 331 332 if (m_return_bp_id == LLDB_INVALID_BREAK_ID) 333 return false; 334 335 if (current_plan) 336 { 337 Breakpoint *return_bp = m_thread.CalculateTarget()->GetBreakpointByID(m_return_bp_id).get(); 338 if (return_bp != NULL) 339 return_bp->SetEnabled (true); 340 } 341 return true; 342 } 343 344 bool 345 ThreadPlanStepOut::WillStop () 346 { 347 if (m_return_bp_id != LLDB_INVALID_BREAK_ID) 348 { 349 Breakpoint *return_bp = m_thread.CalculateTarget()->GetBreakpointByID(m_return_bp_id).get(); 350 if (return_bp != NULL) 351 return_bp->SetEnabled (false); 352 } 353 354 return true; 355 } 356 357 bool 358 ThreadPlanStepOut::MischiefManaged () 359 { 360 if (IsPlanComplete()) 361 { 362 // Did I reach my breakpoint? If so I'm done. 363 // 364 // I also check the stack depth, since if we've blown past the breakpoint for some 365 // reason and we're now stopping for some other reason altogether, then we're done 366 // with this step out operation. 367 368 LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 369 if (log) 370 log->Printf("Completed step out plan."); 371 if (m_return_bp_id != LLDB_INVALID_BREAK_ID) 372 { 373 m_thread.CalculateTarget()->RemoveBreakpointByID (m_return_bp_id); 374 m_return_bp_id = LLDB_INVALID_BREAK_ID; 375 } 376 377 ThreadPlan::MischiefManaged (); 378 return true; 379 } 380 else 381 { 382 return false; 383 } 384 } 385 386 bool 387 ThreadPlanStepOut::QueueInlinedStepPlan (bool queue_now) 388 { 389 // Now figure out the range of this inlined block, and set up a "step through range" 390 // plan for that. If we've been provided with a context, then use the block in that 391 // context. 392 StackFrameSP immediate_return_from_sp (m_thread.GetStackFrameAtIndex (0)); 393 if (!immediate_return_from_sp) 394 return false; 395 396 LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 397 if (log) 398 { 399 StreamString s; 400 immediate_return_from_sp->Dump(&s, true, false); 401 log->Printf("Queuing inlined frame to step past: %s.", s.GetData()); 402 } 403 404 Block *from_block = immediate_return_from_sp->GetFrameBlock(); 405 if (from_block) 406 { 407 Block *inlined_block = from_block->GetContainingInlinedBlock(); 408 if (inlined_block) 409 { 410 size_t num_ranges = inlined_block->GetNumRanges(); 411 AddressRange inline_range; 412 if (inlined_block->GetRangeAtIndex(0, inline_range)) 413 { 414 SymbolContext inlined_sc; 415 inlined_block->CalculateSymbolContext(&inlined_sc); 416 RunMode run_mode = m_stop_others ? lldb::eOnlyThisThread : lldb::eAllThreads; 417 ThreadPlanStepOverRange *step_through_inline_plan_ptr = new ThreadPlanStepOverRange(m_thread, 418 inline_range, 419 inlined_sc, 420 run_mode); 421 step_through_inline_plan_ptr->SetOkayToDiscard(true); 422 StreamString errors; 423 if (!step_through_inline_plan_ptr->ValidatePlan(&errors)) 424 { 425 //FIXME: Log this failure. 426 delete step_through_inline_plan_ptr; 427 return false; 428 } 429 430 for (size_t i = 1; i < num_ranges; i++) 431 { 432 if (inlined_block->GetRangeAtIndex (i, inline_range)) 433 step_through_inline_plan_ptr->AddRange (inline_range); 434 } 435 m_step_through_inline_plan_sp.reset (step_through_inline_plan_ptr); 436 if (queue_now) 437 m_thread.QueueThreadPlan (m_step_through_inline_plan_sp, false); 438 return true; 439 } 440 } 441 } 442 443 return false; 444 } 445 446 void 447 ThreadPlanStepOut::CalculateReturnValue () 448 { 449 if (m_return_valobj_sp) 450 return; 451 452 if (m_immediate_step_from_function != NULL) 453 { 454 Type *return_type = m_immediate_step_from_function->GetType(); 455 lldb::clang_type_t return_clang_type = m_immediate_step_from_function->GetReturnClangType(); 456 if (return_type && return_clang_type) 457 { 458 ClangASTType ast_type (return_type->GetClangAST(), return_clang_type); 459 460 lldb::ABISP abi_sp = m_thread.GetProcess()->GetABI(); 461 if (abi_sp) 462 { 463 m_return_valobj_sp = abi_sp->GetReturnValueObject(m_thread, ast_type); 464 } 465 } 466 } 467 } 468