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 #include "lldb/Target/ThreadPlanStepOverRange.h" 11 #include "lldb/Symbol/Block.h" 12 #include "lldb/Symbol/CompileUnit.h" 13 #include "lldb/Symbol/Function.h" 14 #include "lldb/Symbol/LineTable.h" 15 #include "lldb/Target/Process.h" 16 #include "lldb/Target/RegisterContext.h" 17 #include "lldb/Target/Target.h" 18 #include "lldb/Target/Thread.h" 19 #include "lldb/Target/ThreadPlanStepOut.h" 20 #include "lldb/Target/ThreadPlanStepThrough.h" 21 #include "lldb/Utility/Log.h" 22 #include "lldb/Utility/Stream.h" 23 24 using namespace lldb_private; 25 using namespace lldb; 26 27 uint32_t ThreadPlanStepOverRange::s_default_flag_values = 0; 28 29 //---------------------------------------------------------------------- 30 // ThreadPlanStepOverRange: Step through a stack range, either stepping over or 31 // into based on the value of \a type. 32 //---------------------------------------------------------------------- 33 34 ThreadPlanStepOverRange::ThreadPlanStepOverRange( 35 Thread &thread, const AddressRange &range, 36 const SymbolContext &addr_context, lldb::RunMode stop_others, 37 LazyBool step_out_avoids_code_without_debug_info) 38 : ThreadPlanStepRange(ThreadPlan::eKindStepOverRange, 39 "Step range stepping over", thread, range, 40 addr_context, stop_others), 41 ThreadPlanShouldStopHere(this), m_first_resume(true) { 42 SetFlagsToDefault(); 43 SetupAvoidNoDebug(step_out_avoids_code_without_debug_info); 44 } 45 46 ThreadPlanStepOverRange::~ThreadPlanStepOverRange() = default; 47 48 void ThreadPlanStepOverRange::GetDescription(Stream *s, 49 lldb::DescriptionLevel level) { 50 auto PrintFailureIfAny = [&]() { 51 if (m_status.Success()) 52 return; 53 s->Printf(" failed (%s)", m_status.AsCString()); 54 }; 55 56 if (level == lldb::eDescriptionLevelBrief) { 57 s->Printf("step over"); 58 PrintFailureIfAny(); 59 return; 60 } 61 62 s->Printf("Stepping over"); 63 bool printed_line_info = false; 64 if (m_addr_context.line_entry.IsValid()) { 65 s->Printf(" line "); 66 m_addr_context.line_entry.DumpStopContext(s, false); 67 printed_line_info = true; 68 } 69 70 if (!printed_line_info || level == eDescriptionLevelVerbose) { 71 s->Printf(" using ranges: "); 72 DumpRanges(s); 73 } 74 75 PrintFailureIfAny(); 76 77 s->PutChar('.'); 78 } 79 80 void ThreadPlanStepOverRange::SetupAvoidNoDebug( 81 LazyBool step_out_avoids_code_without_debug_info) { 82 bool avoid_nodebug = true; 83 switch (step_out_avoids_code_without_debug_info) { 84 case eLazyBoolYes: 85 avoid_nodebug = true; 86 break; 87 case eLazyBoolNo: 88 avoid_nodebug = false; 89 break; 90 case eLazyBoolCalculate: 91 avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug(); 92 break; 93 } 94 if (avoid_nodebug) 95 GetFlags().Set(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 96 else 97 GetFlags().Clear(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 98 // Step Over plans should always avoid no-debug on step in. Seems like you 99 // shouldn't have to say this, but a tail call looks more like a step in that 100 // a step out, so we want to catch this case. 101 GetFlags().Set(ThreadPlanShouldStopHere::eStepInAvoidNoDebug); 102 } 103 104 bool ThreadPlanStepOverRange::IsEquivalentContext( 105 const SymbolContext &context) { 106 // Match as much as is specified in the m_addr_context: This is a fairly 107 // loose sanity check. Note, sometimes the target doesn't get filled in so I 108 // left out the target check. And sometimes the module comes in as the .o 109 // file from the inlined range, so I left that out too... 110 if (m_addr_context.comp_unit) { 111 if (m_addr_context.comp_unit != context.comp_unit) 112 return false; 113 if (m_addr_context.function) { 114 if (m_addr_context.function != context.function) 115 return false; 116 // It is okay to return to a different block of a straight function, we 117 // only have to be more careful if returning from one inlined block to 118 // another. 119 if (m_addr_context.block->GetInlinedFunctionInfo() == nullptr && 120 context.block->GetInlinedFunctionInfo() == nullptr) 121 return true; 122 return m_addr_context.block == context.block; 123 } 124 } 125 // Fall back to symbol if we have no decision from comp_unit/function/block. 126 return m_addr_context.symbol && m_addr_context.symbol == context.symbol; 127 } 128 129 bool ThreadPlanStepOverRange::ShouldStop(Event *event_ptr) { 130 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 131 132 if (log) { 133 StreamString s; 134 s.Address( 135 m_thread.GetRegisterContext()->GetPC(), 136 m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize()); 137 log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData()); 138 } 139 140 // If we're out of the range but in the same frame or in our caller's frame 141 // then we should stop. When stepping out we only stop others if we are 142 // forcing running one thread. 143 bool stop_others = (m_stop_others == lldb::eOnlyThisThread); 144 ThreadPlanSP new_plan_sp; 145 FrameComparison frame_order = CompareCurrentFrameToStartFrame(); 146 147 if (frame_order == eFrameCompareOlder) { 148 // If we're in an older frame then we should stop. 149 // 150 // A caveat to this is if we think the frame is older but we're actually in 151 // a trampoline. 152 // I'm going to make the assumption that you wouldn't RETURN to a 153 // trampoline. So if we are in a trampoline we think the frame is older 154 // because the trampoline confused the backtracer. As below, we step 155 // through first, and then try to figure out how to get back out again. 156 157 new_plan_sp = m_thread.QueueThreadPlanForStepThrough(m_stack_id, false, 158 stop_others, m_status); 159 160 if (new_plan_sp && log) 161 log->Printf( 162 "Thought I stepped out, but in fact arrived at a trampoline."); 163 } else if (frame_order == eFrameCompareYounger) { 164 // Make sure we really are in a new frame. Do that by unwinding and seeing 165 // if the start function really is our start function... 166 for (uint32_t i = 1;; ++i) { 167 StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(i); 168 if (!older_frame_sp) { 169 // We can't unwind the next frame we should just get out of here & 170 // stop... 171 break; 172 } 173 174 const SymbolContext &older_context = 175 older_frame_sp->GetSymbolContext(eSymbolContextEverything); 176 if (IsEquivalentContext(older_context)) { 177 new_plan_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop( 178 false, nullptr, true, stop_others, eVoteNo, eVoteNoOpinion, 0, 179 m_status, true); 180 break; 181 } else { 182 new_plan_sp = m_thread.QueueThreadPlanForStepThrough( 183 m_stack_id, false, stop_others, m_status); 184 // If we found a way through, then we should stop recursing. 185 if (new_plan_sp) 186 break; 187 } 188 } 189 } else { 190 // If we're still in the range, keep going. 191 if (InRange()) { 192 SetNextBranchBreakpoint(); 193 return false; 194 } 195 196 if (!InSymbol()) { 197 // This one is a little tricky. Sometimes we may be in a stub or 198 // something similar, in which case we need to get out of there. But if 199 // we are in a stub then it's likely going to be hard to get out from 200 // here. It is probably easiest to step into the stub, and then it will 201 // be straight-forward to step out. 202 new_plan_sp = m_thread.QueueThreadPlanForStepThrough( 203 m_stack_id, false, stop_others, m_status); 204 } else { 205 // The current clang (at least through 424) doesn't always get the 206 // address range for the DW_TAG_inlined_subroutines right, so that when 207 // you leave the inlined range the line table says you are still in the 208 // source file of the inlining function. This is bad, because now you 209 // are missing the stack frame for the function containing the inlining, 210 // and if you sensibly do "finish" to get out of this function you will 211 // instead exit the containing function. To work around this, we check 212 // whether we are still in the source file we started in, and if not 213 // assume it is an error, and push a plan to get us out of this line and 214 // back to the containing file. 215 216 if (m_addr_context.line_entry.IsValid()) { 217 SymbolContext sc; 218 StackFrameSP frame_sp = m_thread.GetStackFrameAtIndex(0); 219 sc = frame_sp->GetSymbolContext(eSymbolContextEverything); 220 if (sc.line_entry.IsValid()) { 221 if (sc.line_entry.original_file != 222 m_addr_context.line_entry.original_file && 223 sc.comp_unit == m_addr_context.comp_unit && 224 sc.function == m_addr_context.function) { 225 // Okay, find the next occurrence of this file in the line table: 226 LineTable *line_table = m_addr_context.comp_unit->GetLineTable(); 227 if (line_table) { 228 Address cur_address = frame_sp->GetFrameCodeAddress(); 229 uint32_t entry_idx; 230 LineEntry line_entry; 231 if (line_table->FindLineEntryByAddress(cur_address, line_entry, 232 &entry_idx)) { 233 LineEntry next_line_entry; 234 bool step_past_remaining_inline = false; 235 if (entry_idx > 0) { 236 // We require the previous line entry and the current line 237 // entry come from the same file. The other requirement is 238 // that the previous line table entry be part of an inlined 239 // block, we don't want to step past cases where people have 240 // inlined some code fragment by using #include <source- 241 // fragment.c> directly. 242 LineEntry prev_line_entry; 243 if (line_table->GetLineEntryAtIndex(entry_idx - 1, 244 prev_line_entry) && 245 prev_line_entry.original_file == 246 line_entry.original_file) { 247 SymbolContext prev_sc; 248 Address prev_address = 249 prev_line_entry.range.GetBaseAddress(); 250 prev_address.CalculateSymbolContext(&prev_sc); 251 if (prev_sc.block) { 252 Block *inlined_block = 253 prev_sc.block->GetContainingInlinedBlock(); 254 if (inlined_block) { 255 AddressRange inline_range; 256 inlined_block->GetRangeContainingAddress(prev_address, 257 inline_range); 258 if (!inline_range.ContainsFileAddress(cur_address)) { 259 260 step_past_remaining_inline = true; 261 } 262 } 263 } 264 } 265 } 266 267 if (step_past_remaining_inline) { 268 uint32_t look_ahead_step = 1; 269 while (line_table->GetLineEntryAtIndex( 270 entry_idx + look_ahead_step, next_line_entry)) { 271 // Make sure we haven't wandered out of the function we 272 // started from... 273 Address next_line_address = 274 next_line_entry.range.GetBaseAddress(); 275 Function *next_line_function = 276 next_line_address.CalculateSymbolContextFunction(); 277 if (next_line_function != m_addr_context.function) 278 break; 279 280 if (next_line_entry.original_file == 281 m_addr_context.line_entry.original_file) { 282 const bool abort_other_plans = false; 283 const RunMode stop_other_threads = RunMode::eAllThreads; 284 lldb::addr_t cur_pc = m_thread.GetStackFrameAtIndex(0) 285 ->GetRegisterContext() 286 ->GetPC(); 287 AddressRange step_range( 288 cur_pc, 289 next_line_address.GetLoadAddress(&GetTarget()) - 290 cur_pc); 291 292 new_plan_sp = m_thread.QueueThreadPlanForStepOverRange( 293 abort_other_plans, step_range, sc, stop_other_threads, 294 m_status); 295 break; 296 } 297 look_ahead_step++; 298 } 299 } 300 } 301 } 302 } 303 } 304 } 305 } 306 } 307 308 // If we get to this point, we're not going to use a previously set "next 309 // branch" breakpoint, so delete it: 310 ClearNextBranchBreakpoint(); 311 312 // If we haven't figured out something to do yet, then ask the ShouldStopHere 313 // callback: 314 if (!new_plan_sp) { 315 new_plan_sp = CheckShouldStopHereAndQueueStepOut(frame_order, m_status); 316 } 317 318 if (!new_plan_sp) 319 m_no_more_plans = true; 320 else { 321 // Any new plan will be an implementation plan, so mark it private: 322 new_plan_sp->SetPrivate(true); 323 m_no_more_plans = false; 324 } 325 326 if (!new_plan_sp) { 327 // For efficiencies sake, we know we're done here so we don't have to do 328 // this calculation again in MischiefManaged. 329 SetPlanComplete(m_status.Success()); 330 return true; 331 } else 332 return false; 333 } 334 335 bool ThreadPlanStepOverRange::DoPlanExplainsStop(Event *event_ptr) { 336 // For crashes, breakpoint hits, signals, etc, let the base plan (or some 337 // plan above us) handle the stop. That way the user can see the stop, step 338 // around, and then when they are done, continue and have their step 339 // complete. The exception is if we've hit our "run to next branch" 340 // breakpoint. Note, unlike the step in range plan, we don't mark ourselves 341 // complete if we hit an unexplained breakpoint/crash. 342 343 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 344 StopInfoSP stop_info_sp = GetPrivateStopInfo(); 345 bool return_value; 346 347 if (stop_info_sp) { 348 StopReason reason = stop_info_sp->GetStopReason(); 349 350 if (reason == eStopReasonTrace) { 351 return_value = true; 352 } else if (reason == eStopReasonBreakpoint) { 353 return_value = NextRangeBreakpointExplainsStop(stop_info_sp); 354 } else { 355 if (log) 356 log->PutCString("ThreadPlanStepInRange got asked if it explains the " 357 "stop for some reason other than step."); 358 return_value = false; 359 } 360 } else 361 return_value = true; 362 363 return return_value; 364 } 365 366 bool ThreadPlanStepOverRange::DoWillResume(lldb::StateType resume_state, 367 bool current_plan) { 368 if (resume_state != eStateSuspended && m_first_resume) { 369 m_first_resume = false; 370 if (resume_state == eStateStepping && current_plan) { 371 // See if we are about to step over an inlined call in the middle of the 372 // inlined stack, if so figure out its extents and reset our range to 373 // step over that. 374 bool in_inlined_stack = m_thread.DecrementCurrentInlinedDepth(); 375 if (in_inlined_stack) { 376 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP)); 377 if (log) 378 log->Printf("ThreadPlanStepInRange::DoWillResume: adjusting range to " 379 "the frame at inlined depth %d.", 380 m_thread.GetCurrentInlinedDepth()); 381 StackFrameSP stack_sp = m_thread.GetStackFrameAtIndex(0); 382 if (stack_sp) { 383 Block *frame_block = stack_sp->GetFrameBlock(); 384 lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC(); 385 AddressRange my_range; 386 if (frame_block->GetRangeContainingLoadAddress( 387 curr_pc, m_thread.GetProcess()->GetTarget(), my_range)) { 388 m_address_ranges.clear(); 389 m_address_ranges.push_back(my_range); 390 if (log) { 391 StreamString s; 392 const InlineFunctionInfo *inline_info = 393 frame_block->GetInlinedFunctionInfo(); 394 const char *name; 395 if (inline_info) 396 name = 397 inline_info 398 ->GetName(frame_block->CalculateSymbolContextFunction() 399 ->GetLanguage()) 400 .AsCString(); 401 else 402 name = "<unknown-notinlined>"; 403 404 s.Printf( 405 "Stepping over inlined function \"%s\" in inlined stack: ", 406 name); 407 DumpRanges(&s); 408 log->PutString(s.GetString()); 409 } 410 } 411 } 412 } 413 } 414 } 415 416 return true; 417 } 418