1 //===-- ThreadPlanStepOverRange.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/ThreadPlanStepOverRange.h" 15 #include "lldb/Core/Log.h" 16 #include "lldb/Core/Stream.h" 17 #include "lldb/Symbol/Block.h" 18 #include "lldb/Symbol/CompileUnit.h" 19 #include "lldb/Symbol/Function.h" 20 #include "lldb/Symbol/LineTable.h" 21 #include "lldb/Target/Process.h" 22 #include "lldb/Target/RegisterContext.h" 23 #include "lldb/Target/Target.h" 24 #include "lldb/Target/Thread.h" 25 #include "lldb/Target/ThreadPlanStepOut.h" 26 #include "lldb/Target/ThreadPlanStepThrough.h" 27 28 using namespace lldb_private; 29 using namespace lldb; 30 31 uint32_t ThreadPlanStepOverRange::s_default_flag_values = 0; 32 33 //---------------------------------------------------------------------- 34 // ThreadPlanStepOverRange: Step through a stack range, either stepping over or into 35 // based on the value of \a type. 36 //---------------------------------------------------------------------- 37 38 ThreadPlanStepOverRange::ThreadPlanStepOverRange 39 ( 40 Thread &thread, 41 const AddressRange &range, 42 const SymbolContext &addr_context, 43 lldb::RunMode stop_others, 44 LazyBool step_out_avoids_code_without_debug_info 45 ) : 46 ThreadPlanStepRange (ThreadPlan::eKindStepOverRange, "Step range stepping over", thread, range, addr_context, stop_others), 47 ThreadPlanShouldStopHere (this), 48 m_first_resume(true) 49 { 50 SetFlagsToDefault(); 51 SetupAvoidNoDebug(step_out_avoids_code_without_debug_info); 52 } 53 54 ThreadPlanStepOverRange::~ThreadPlanStepOverRange() = default; 55 56 void 57 ThreadPlanStepOverRange::GetDescription (Stream *s, lldb::DescriptionLevel level) 58 { 59 if (level == lldb::eDescriptionLevelBrief) 60 { 61 s->Printf("step over"); 62 return; 63 } 64 s->Printf ("Stepping over"); 65 bool printed_line_info = false; 66 if (m_addr_context.line_entry.IsValid()) 67 { 68 s->Printf (" line "); 69 m_addr_context.line_entry.DumpStopContext (s, false); 70 printed_line_info = true; 71 } 72 73 if (!printed_line_info || level == eDescriptionLevelVerbose) 74 { 75 s->Printf (" using ranges: "); 76 DumpRanges(s); 77 } 78 79 s->PutChar('.'); 80 } 81 82 void 83 ThreadPlanStepOverRange::SetupAvoidNoDebug(LazyBool step_out_avoids_code_without_debug_info) 84 { 85 bool avoid_nodebug = true; 86 switch (step_out_avoids_code_without_debug_info) 87 { 88 case eLazyBoolYes: 89 avoid_nodebug = true; 90 break; 91 case eLazyBoolNo: 92 avoid_nodebug = false; 93 break; 94 case eLazyBoolCalculate: 95 avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug(); 96 break; 97 } 98 if (avoid_nodebug) 99 GetFlags().Set (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 100 else 101 GetFlags().Clear (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 102 // Step Over plans should always avoid no-debug on step in. Seems like you shouldn't 103 // have to say this, but a tail call looks more like a step in that a step out, so 104 // we want to catch this case. 105 GetFlags().Set (ThreadPlanShouldStopHere::eStepInAvoidNoDebug); 106 } 107 108 bool 109 ThreadPlanStepOverRange::IsEquivalentContext(const SymbolContext &context) 110 { 111 // Match as much as is specified in the m_addr_context: 112 // This is a fairly loose sanity check. Note, sometimes the target doesn't get filled 113 // in so I left out the target check. And sometimes the module comes in as the .o file from the 114 // inlined range, so I left that out too... 115 if (m_addr_context.comp_unit) 116 { 117 if (m_addr_context.comp_unit == context.comp_unit) 118 { 119 if (m_addr_context.function && m_addr_context.function == context.function) 120 { 121 // It is okay to return to a different block of a straight function, we only have to 122 // be more careful if returning from one inlined block to another. 123 if (m_addr_context.block->GetInlinedFunctionInfo() == nullptr 124 && context.block->GetInlinedFunctionInfo() == nullptr) 125 return true; 126 127 if (m_addr_context.block && m_addr_context.block == context.block) 128 return true; 129 } 130 } 131 } 132 else if (m_addr_context.symbol && m_addr_context.symbol == context.symbol) 133 { 134 return true; 135 } 136 return false; 137 } 138 139 bool 140 ThreadPlanStepOverRange::ShouldStop (Event *event_ptr) 141 { 142 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 143 144 if (log) 145 { 146 StreamString s; 147 s.Address (m_thread.GetRegisterContext()->GetPC(), 148 m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize()); 149 log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData()); 150 } 151 152 // If we're out of the range but in the same frame or in our caller's frame 153 // then we should stop. 154 // When stepping out we only stop others if we are forcing running one thread. 155 bool stop_others = (m_stop_others == lldb::eOnlyThisThread); 156 ThreadPlanSP new_plan_sp; 157 FrameComparison frame_order = CompareCurrentFrameToStartFrame(); 158 159 if (frame_order == eFrameCompareOlder) 160 { 161 // If we're in an older frame then we should stop. 162 // 163 // A caveat to this is if we think the frame is older but we're actually in a trampoline. 164 // I'm going to make the assumption that you wouldn't RETURN to a trampoline. So if we are 165 // in a trampoline we think the frame is older because the trampoline confused the backtracer. 166 // As below, we step through first, and then try to figure out how to get back out again. 167 168 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others); 169 170 if (new_plan_sp && log) 171 log->Printf("Thought I stepped out, but in fact arrived at a trampoline."); 172 } 173 else if (frame_order == eFrameCompareYounger) 174 { 175 // Make sure we really are in a new frame. Do that by unwinding and seeing if the 176 // start function really is our start function... 177 for(uint32_t i = 1;; ++i) 178 { 179 StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(i); 180 if (!older_frame_sp) { 181 // We can't unwind the next frame we should just get out of here & stop... 182 break; 183 } 184 185 const SymbolContext &older_context = older_frame_sp->GetSymbolContext(eSymbolContextEverything); 186 if (IsEquivalentContext(older_context)) 187 { 188 new_plan_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop(false, 189 nullptr, 190 true, 191 stop_others, 192 eVoteNo, 193 eVoteNoOpinion, 194 0, 195 true); 196 break; 197 } 198 else 199 { 200 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others); 201 // If we found a way through, then we should stop recursing. 202 if (new_plan_sp) 203 break; 204 } 205 } 206 } 207 else 208 { 209 // If we're still in the range, keep going. 210 if (InRange()) 211 { 212 SetNextBranchBreakpoint(); 213 return false; 214 } 215 216 if (!InSymbol()) 217 { 218 // This one is a little tricky. Sometimes we may be in a stub or something similar, 219 // in which case we need to get out of there. But if we are in a stub then it's 220 // likely going to be hard to get out from here. It is probably easiest to step into the 221 // stub, and then it will be straight-forward to step out. 222 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others); 223 } 224 else 225 { 226 // The current clang (at least through 424) doesn't always get the address range for the 227 // DW_TAG_inlined_subroutines right, so that when you leave the inlined range the line table says 228 // you are still in the source file of the inlining function. This is bad, because now you are missing 229 // the stack frame for the function containing the inlining, and if you sensibly do "finish" to get 230 // out of this function you will instead exit the containing function. 231 // To work around this, we check whether we are still in the source file we started in, and if not assume 232 // it is an error, and push a plan to get us out of this line and back to the containing file. 233 234 if (m_addr_context.line_entry.IsValid()) 235 { 236 SymbolContext sc; 237 StackFrameSP frame_sp = m_thread.GetStackFrameAtIndex(0); 238 sc = frame_sp->GetSymbolContext (eSymbolContextEverything); 239 if (sc.line_entry.IsValid()) 240 { 241 if (sc.line_entry.original_file != m_addr_context.line_entry.original_file 242 && sc.comp_unit == m_addr_context.comp_unit 243 && sc.function == m_addr_context.function) 244 { 245 // Okay, find the next occurrence of this file in the line table: 246 LineTable *line_table = m_addr_context.comp_unit->GetLineTable(); 247 if (line_table) 248 { 249 Address cur_address = frame_sp->GetFrameCodeAddress(); 250 uint32_t entry_idx; 251 LineEntry line_entry; 252 if (line_table->FindLineEntryByAddress (cur_address, line_entry, &entry_idx)) 253 { 254 LineEntry next_line_entry; 255 bool step_past_remaining_inline = false; 256 if (entry_idx > 0) 257 { 258 // We require the previous line entry and the current line entry come 259 // from the same file. 260 // The other requirement is that the previous line table entry be part of an 261 // inlined block, we don't want to step past cases where people have inlined 262 // some code fragment by using #include <source-fragment.c> directly. 263 LineEntry prev_line_entry; 264 if (line_table->GetLineEntryAtIndex(entry_idx - 1, prev_line_entry) 265 && prev_line_entry.original_file == line_entry.original_file) 266 { 267 SymbolContext prev_sc; 268 Address prev_address = prev_line_entry.range.GetBaseAddress(); 269 prev_address.CalculateSymbolContext(&prev_sc); 270 if (prev_sc.block) 271 { 272 Block *inlined_block = prev_sc.block->GetContainingInlinedBlock(); 273 if (inlined_block) 274 { 275 AddressRange inline_range; 276 inlined_block->GetRangeContainingAddress(prev_address, inline_range); 277 if (!inline_range.ContainsFileAddress(cur_address)) 278 { 279 280 step_past_remaining_inline = true; 281 } 282 } 283 } 284 } 285 } 286 287 if (step_past_remaining_inline) 288 { 289 uint32_t look_ahead_step = 1; 290 while (line_table->GetLineEntryAtIndex(entry_idx + look_ahead_step, next_line_entry)) 291 { 292 // Make sure we haven't wandered out of the function we started from... 293 Address next_line_address = next_line_entry.range.GetBaseAddress(); 294 Function *next_line_function = next_line_address.CalculateSymbolContextFunction(); 295 if (next_line_function != m_addr_context.function) 296 break; 297 298 if (next_line_entry.original_file == m_addr_context.line_entry.original_file) 299 { 300 const bool abort_other_plans = false; 301 const RunMode stop_other_threads = RunMode::eAllThreads; 302 lldb::addr_t cur_pc = m_thread.GetStackFrameAtIndex(0)->GetRegisterContext()->GetPC(); 303 AddressRange step_range(cur_pc, next_line_address.GetLoadAddress(&GetTarget()) - cur_pc); 304 305 new_plan_sp = m_thread.QueueThreadPlanForStepOverRange (abort_other_plans, 306 step_range, 307 sc, 308 stop_other_threads); 309 break; 310 } 311 look_ahead_step++; 312 } 313 } 314 } 315 } 316 } 317 } 318 } 319 } 320 } 321 322 // If we get to this point, we're not going to use a previously set "next branch" breakpoint, so delete it: 323 ClearNextBranchBreakpoint(); 324 325 326 // If we haven't figured out something to do yet, then ask the ShouldStopHere callback: 327 if (!new_plan_sp) 328 { 329 new_plan_sp = CheckShouldStopHereAndQueueStepOut (frame_order); 330 } 331 332 if (!new_plan_sp) 333 m_no_more_plans = true; 334 else 335 { 336 // Any new plan will be an implementation plan, so mark it private: 337 new_plan_sp->SetPrivate(true); 338 m_no_more_plans = false; 339 } 340 341 if (!new_plan_sp) 342 { 343 // For efficiencies sake, we know we're done here so we don't have to do this 344 // calculation again in MischiefManaged. 345 SetPlanComplete(); 346 return true; 347 } 348 else 349 return false; 350 } 351 352 bool 353 ThreadPlanStepOverRange::DoPlanExplainsStop (Event *event_ptr) 354 { 355 // For crashes, breakpoint hits, signals, etc, let the base plan (or some plan above us) 356 // handle the stop. That way the user can see the stop, step around, and then when they 357 // are done, continue and have their step complete. The exception is if we've hit our 358 // "run to next branch" breakpoint. 359 // Note, unlike the step in range plan, we don't mark ourselves complete if we hit an 360 // unexplained breakpoint/crash. 361 362 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 363 StopInfoSP stop_info_sp = GetPrivateStopInfo (); 364 bool return_value; 365 366 if (stop_info_sp) 367 { 368 StopReason reason = stop_info_sp->GetStopReason(); 369 370 if (reason == eStopReasonTrace) 371 { 372 return_value = true; 373 } 374 else if (reason == eStopReasonBreakpoint) 375 { 376 return_value = NextRangeBreakpointExplainsStop(stop_info_sp); 377 } 378 else 379 { 380 if (log) 381 log->PutCString ("ThreadPlanStepInRange got asked if it explains the stop for some reason other than step."); 382 return_value = false; 383 } 384 } 385 else 386 return_value = true; 387 388 return return_value; 389 } 390 391 bool 392 ThreadPlanStepOverRange::DoWillResume (lldb::StateType resume_state, bool current_plan) 393 { 394 if (resume_state != eStateSuspended && m_first_resume) 395 { 396 m_first_resume = false; 397 if (resume_state == eStateStepping && current_plan) 398 { 399 // See if we are about to step over an inlined call in the middle of the inlined stack, if so figure 400 // out its extents and reset our range to step over that. 401 bool in_inlined_stack = m_thread.DecrementCurrentInlinedDepth(); 402 if (in_inlined_stack) 403 { 404 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 405 if (log) 406 log->Printf ("ThreadPlanStepInRange::DoWillResume: adjusting range to the frame at inlined depth %d.", 407 m_thread.GetCurrentInlinedDepth()); 408 StackFrameSP stack_sp = m_thread.GetStackFrameAtIndex(0); 409 if (stack_sp) 410 { 411 Block *frame_block = stack_sp->GetFrameBlock(); 412 lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC(); 413 AddressRange my_range; 414 if (frame_block->GetRangeContainingLoadAddress(curr_pc, m_thread.GetProcess()->GetTarget(), my_range)) 415 { 416 m_address_ranges.clear(); 417 m_address_ranges.push_back(my_range); 418 if (log) 419 { 420 StreamString s; 421 const InlineFunctionInfo *inline_info = frame_block->GetInlinedFunctionInfo(); 422 const char *name; 423 if (inline_info) 424 name = inline_info->GetName(frame_block->CalculateSymbolContextFunction()->GetLanguage()).AsCString(); 425 else 426 name = "<unknown-notinlined>"; 427 428 s.Printf ("Stepping over inlined function \"%s\" in inlined stack: ", name); 429 DumpRanges(&s); 430 log->PutCString(s.GetData()); 431 } 432 } 433 434 } 435 } 436 } 437 } 438 439 return true; 440 } 441