1 //===-- ThreadPlanStepOverRange.cpp ---------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "lldb/Target/ThreadPlanStepOverRange.h" 10 #include "lldb/Symbol/Block.h" 11 #include "lldb/Symbol/CompileUnit.h" 12 #include "lldb/Symbol/Function.h" 13 #include "lldb/Symbol/LineTable.h" 14 #include "lldb/Target/Language.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/ThreadPlanSingleThreadTimeout.h" 20 #include "lldb/Target/ThreadPlanStepOut.h" 21 #include "lldb/Target/ThreadPlanStepThrough.h" 22 #include "lldb/Utility/LLDBLog.h" 23 #include "lldb/Utility/Log.h" 24 #include "lldb/Utility/Stream.h" 25 26 using namespace lldb_private; 27 using namespace lldb; 28 29 uint32_t ThreadPlanStepOverRange::s_default_flag_values = 0; 30 31 // ThreadPlanStepOverRange: Step through a stack range, either stepping over or 32 // into based on the value of \a type. 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), TimeoutResumeAll(thread), 42 m_first_resume(true), m_run_mode(stop_others) { 43 SetFlagsToDefault(); 44 SetupAvoidNoDebug(step_out_avoids_code_without_debug_info); 45 } 46 47 ThreadPlanStepOverRange::~ThreadPlanStepOverRange() = default; 48 49 void ThreadPlanStepOverRange::GetDescription(Stream *s, 50 lldb::DescriptionLevel level) { 51 auto PrintFailureIfAny = [&]() { 52 if (m_status.Success()) 53 return; 54 s->Printf(" failed (%s)", m_status.AsCString()); 55 }; 56 57 if (level == lldb::eDescriptionLevelBrief) { 58 s->Printf("step over"); 59 PrintFailureIfAny(); 60 return; 61 } 62 63 s->Printf("Stepping over"); 64 bool printed_line_info = false; 65 if (m_addr_context.line_entry.IsValid()) { 66 s->Printf(" line "); 67 m_addr_context.line_entry.DumpStopContext(s, false); 68 printed_line_info = true; 69 } 70 71 if (!printed_line_info || level == eDescriptionLevelVerbose) { 72 s->Printf(" using ranges: "); 73 DumpRanges(s); 74 } 75 76 PrintFailureIfAny(); 77 78 s->PutChar('.'); 79 } 80 81 void ThreadPlanStepOverRange::SetupAvoidNoDebug( 82 LazyBool step_out_avoids_code_without_debug_info) { 83 bool avoid_nodebug = true; 84 switch (step_out_avoids_code_without_debug_info) { 85 case eLazyBoolYes: 86 avoid_nodebug = true; 87 break; 88 case eLazyBoolNo: 89 avoid_nodebug = false; 90 break; 91 case eLazyBoolCalculate: 92 avoid_nodebug = GetThread().GetStepOutAvoidsNoDebug(); 93 break; 94 } 95 if (avoid_nodebug) 96 GetFlags().Set(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 97 else 98 GetFlags().Clear(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 99 // Step Over plans should always avoid no-debug on step in. Seems like you 100 // shouldn't have to say this, but a tail call looks more like a step in that 101 // a step out, so we want to catch this case. 102 GetFlags().Set(ThreadPlanShouldStopHere::eStepInAvoidNoDebug); 103 } 104 105 bool ThreadPlanStepOverRange::IsEquivalentContext( 106 const SymbolContext &context) { 107 if (Language *language = Language::FindPlugin(context.GetLanguage())) 108 if (std::optional<bool> maybe_equivalent = 109 language->AreEqualForFrameComparison(context, m_addr_context)) 110 return *maybe_equivalent; 111 // Match as much as is specified in the m_addr_context: This is a fairly 112 // loose sanity check. Note, sometimes the target doesn't get filled in so I 113 // left out the target check. And sometimes the module comes in as the .o 114 // file from the inlined range, so I left that out too... 115 if (m_addr_context.comp_unit) { 116 if (m_addr_context.comp_unit != context.comp_unit) 117 return false; 118 if (m_addr_context.function) { 119 if (m_addr_context.function != context.function) 120 return false; 121 // It is okay to return to a different block of a straight function, we 122 // only have to be more careful if returning from one inlined block to 123 // another. 124 if (m_addr_context.block->GetInlinedFunctionInfo() == nullptr && 125 context.block->GetInlinedFunctionInfo() == nullptr) 126 return true; 127 return m_addr_context.block == context.block; 128 } 129 } 130 // Fall back to symbol if we have no decision from comp_unit/function/block. 131 return m_addr_context.symbol && m_addr_context.symbol == context.symbol; 132 } 133 134 void ThreadPlanStepOverRange::SetStopOthers(bool stop_others) { 135 if (!stop_others) 136 m_stop_others = RunMode::eAllThreads; 137 } 138 139 bool ThreadPlanStepOverRange::ShouldStop(Event *event_ptr) { 140 Log *log = GetLog(LLDBLog::Step); 141 Thread &thread = GetThread(); 142 143 if (log) { 144 StreamString s; 145 DumpAddress(s.AsRawOstream(), thread.GetRegisterContext()->GetPC(), 146 GetTarget().GetArchitecture().GetAddressByteSize()); 147 LLDB_LOGF(log, "ThreadPlanStepOverRange reached %s.", s.GetData()); 148 } 149 ClearNextBranchBreakpointExplainedStop(); 150 151 // If we're out of the range but in the same frame or in our caller's frame 152 // then we should stop. When stepping out we only stop others if we are 153 // forcing running one thread. 154 bool stop_others = (m_stop_others == lldb::eOnlyThisThread); 155 ThreadPlanSP new_plan_sp; 156 FrameComparison frame_order = CompareCurrentFrameToStartFrame(); 157 LLDB_LOGF(log, "ThreadPlanStepOverRange compare frame result: %d.", 158 frame_order); 159 160 if (frame_order == eFrameCompareOlder) { 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 164 // a trampoline. 165 // I'm going to make the assumption that you wouldn't RETURN to a 166 // trampoline. So if we are in a trampoline we think the frame is older 167 // because the trampoline confused the backtracer. As below, we step 168 // through first, and then try to figure out how to get back out again. 169 170 new_plan_sp = thread.QueueThreadPlanForStepThrough(m_stack_id, false, 171 stop_others, m_status); 172 173 if (new_plan_sp && log) 174 LLDB_LOGF(log, 175 "Thought I stepped out, but in fact arrived at a trampoline."); 176 } else if (frame_order == eFrameCompareYounger) { 177 // Make sure we really are in a new frame. Do that by unwinding and seeing 178 // if the start function really is our start function... 179 for (uint32_t i = 1;; ++i) { 180 StackFrameSP older_frame_sp = thread.GetStackFrameAtIndex(i); 181 if (!older_frame_sp) { 182 // We can't unwind the next frame we should just get out of here & 183 // stop... 184 break; 185 } 186 187 const SymbolContext &older_context = 188 older_frame_sp->GetSymbolContext(eSymbolContextEverything); 189 if (IsEquivalentContext(older_context)) { 190 // If we have the next-branch-breakpoint in the range, we can just 191 // rely on that breakpoint to trigger once we return to the range. 192 if (m_next_branch_bp_sp) 193 return false; 194 new_plan_sp = thread.QueueThreadPlanForStepOutNoShouldStop( 195 false, nullptr, true, stop_others, eVoteNo, eVoteNoOpinion, 0, 196 m_status, true); 197 break; 198 } else { 199 new_plan_sp = thread.QueueThreadPlanForStepThrough( 200 m_stack_id, false, stop_others, m_status); 201 // If we found a way through, then we should stop recursing. 202 if (new_plan_sp) 203 break; 204 } 205 } 206 } else { 207 // If we're still in the range, keep going. 208 if (InRange()) { 209 SetNextBranchBreakpoint(); 210 return false; 211 } 212 213 if (!InSymbol()) { 214 // This one is a little tricky. Sometimes we may be in a stub or 215 // something similar, in which case we need to get out of there. But if 216 // we are in a stub then it's likely going to be hard to get out from 217 // here. It is probably easiest to step into the stub, and then it will 218 // be straight-forward to step out. 219 new_plan_sp = thread.QueueThreadPlanForStepThrough(m_stack_id, false, 220 stop_others, m_status); 221 } else { 222 // The current clang (at least through 424) doesn't always get the 223 // address range for the DW_TAG_inlined_subroutines right, so that when 224 // you leave the inlined range the line table says you are still in the 225 // source file of the inlining function. This is bad, because now you 226 // are missing the stack frame for the function containing the inlining, 227 // and if you sensibly do "finish" to get out of this function you will 228 // instead exit the containing function. To work around this, we check 229 // whether we are still in the source file we started in, and if not 230 // assume it is an error, and push a plan to get us out of this line and 231 // back to the containing file. 232 233 if (m_addr_context.line_entry.IsValid()) { 234 SymbolContext sc; 235 StackFrameSP frame_sp = thread.GetStackFrameAtIndex(0); 236 sc = frame_sp->GetSymbolContext(eSymbolContextEverything); 237 if (sc.line_entry.IsValid()) { 238 if (!sc.line_entry.original_file_sp->Equal( 239 *m_addr_context.line_entry.original_file_sp, 240 SupportFile::eEqualFileSpecAndChecksumIfSet) && 241 sc.comp_unit == m_addr_context.comp_unit && 242 sc.function == m_addr_context.function) { 243 // Okay, find the next occurrence of this file in the line table: 244 LineTable *line_table = m_addr_context.comp_unit->GetLineTable(); 245 if (line_table) { 246 Address cur_address = frame_sp->GetFrameCodeAddress(); 247 uint32_t entry_idx; 248 LineEntry line_entry; 249 if (line_table->FindLineEntryByAddress(cur_address, line_entry, 250 &entry_idx)) { 251 LineEntry next_line_entry; 252 bool step_past_remaining_inline = false; 253 if (entry_idx > 0) { 254 // We require the previous line entry and the current line 255 // entry come from the same file. The other requirement is 256 // that the previous line table entry be part of an inlined 257 // block, we don't want to step past cases where people have 258 // inlined some code fragment by using #include <source- 259 // fragment.c> directly. 260 LineEntry prev_line_entry; 261 if (line_table->GetLineEntryAtIndex(entry_idx - 1, 262 prev_line_entry) && 263 prev_line_entry.original_file_sp->Equal( 264 *line_entry.original_file_sp, 265 SupportFile::eEqualFileSpecAndChecksumIfSet)) { 266 SymbolContext prev_sc; 267 Address prev_address = 268 prev_line_entry.range.GetBaseAddress(); 269 prev_address.CalculateSymbolContext(&prev_sc); 270 if (prev_sc.block) { 271 Block *inlined_block = 272 prev_sc.block->GetContainingInlinedBlock(); 273 if (inlined_block) { 274 AddressRange inline_range; 275 inlined_block->GetRangeContainingAddress(prev_address, 276 inline_range); 277 if (!inline_range.ContainsFileAddress(cur_address)) { 278 279 step_past_remaining_inline = true; 280 } 281 } 282 } 283 } 284 } 285 286 if (step_past_remaining_inline) { 287 uint32_t look_ahead_step = 1; 288 while (line_table->GetLineEntryAtIndex( 289 entry_idx + look_ahead_step, next_line_entry)) { 290 // Make sure we haven't wandered out of the function we 291 // started from... 292 Address next_line_address = 293 next_line_entry.range.GetBaseAddress(); 294 Function *next_line_function = 295 next_line_address.CalculateSymbolContextFunction(); 296 if (next_line_function != m_addr_context.function) 297 break; 298 299 if (next_line_entry.original_file_sp->Equal( 300 *m_addr_context.line_entry.original_file_sp, 301 SupportFile::eEqualFileSpecAndChecksumIfSet)) { 302 const bool abort_other_plans = false; 303 const RunMode stop_other_threads = RunMode::eAllThreads; 304 lldb::addr_t cur_pc = thread.GetStackFrameAtIndex(0) 305 ->GetRegisterContext() 306 ->GetPC(); 307 AddressRange step_range( 308 cur_pc, 309 next_line_address.GetLoadAddress(&GetTarget()) - 310 cur_pc); 311 312 new_plan_sp = thread.QueueThreadPlanForStepOverRange( 313 abort_other_plans, step_range, sc, stop_other_threads, 314 m_status); 315 break; 316 } 317 look_ahead_step++; 318 } 319 } 320 } 321 } 322 } 323 } 324 } 325 } 326 } 327 328 // If we get to this point, we're not going to use a previously set "next 329 // branch" breakpoint, so delete it: 330 ClearNextBranchBreakpoint(); 331 332 // If we haven't figured out something to do yet, then ask the ShouldStopHere 333 // callback: 334 if (!new_plan_sp) { 335 new_plan_sp = CheckShouldStopHereAndQueueStepOut(frame_order, m_status); 336 } 337 338 if (!new_plan_sp) 339 m_no_more_plans = true; 340 else { 341 // Any new plan will be an implementation plan, so mark it private: 342 new_plan_sp->SetPrivate(true); 343 m_no_more_plans = false; 344 } 345 346 if (!new_plan_sp) { 347 // For efficiencies sake, we know we're done here so we don't have to do 348 // this calculation again in MischiefManaged. 349 SetPlanComplete(m_status.Success()); 350 return true; 351 } else 352 return false; 353 } 354 355 void ThreadPlanStepOverRange::DidPush() { 356 ThreadPlanStepRange::DidPush(); 357 if (m_run_mode == lldb::eOnlyThisThread && IsControllingPlan()) 358 PushNewTimeout(); 359 } 360 361 bool ThreadPlanStepOverRange::DoPlanExplainsStop(Event *event_ptr) { 362 // For crashes, breakpoint hits, signals, etc, let the base plan (or some 363 // plan above us) handle the stop. That way the user can see the stop, step 364 // around, and then when they are done, continue and have their step 365 // complete. The exception is if we've hit our "run to next branch" 366 // breakpoint. Note, unlike the step in range plan, we don't mark ourselves 367 // complete if we hit an unexplained breakpoint/crash. 368 369 Log *log = GetLog(LLDBLog::Step); 370 StopInfoSP stop_info_sp = GetPrivateStopInfo(); 371 bool return_value; 372 373 if (stop_info_sp) { 374 StopReason reason = stop_info_sp->GetStopReason(); 375 376 if (reason == eStopReasonTrace) { 377 return_value = true; 378 } else if (reason == eStopReasonBreakpoint) { 379 return_value = NextRangeBreakpointExplainsStop(stop_info_sp); 380 } else { 381 if (log) 382 log->PutCString("ThreadPlanStepOverRange got asked if it explains the " 383 "stop for some reason other than step."); 384 return_value = false; 385 } 386 } else 387 return_value = true; 388 389 return return_value; 390 } 391 392 bool ThreadPlanStepOverRange::DoWillResume(lldb::StateType resume_state, 393 bool current_plan) { 394 if (resume_state != eStateSuspended && m_first_resume) { 395 m_first_resume = false; 396 if (resume_state == eStateStepping && current_plan) { 397 Thread &thread = GetThread(); 398 // See if we are about to step over an inlined call in the middle of the 399 // inlined stack, if so figure out its extents and reset our range to 400 // step over that. 401 bool in_inlined_stack = thread.DecrementCurrentInlinedDepth(); 402 if (in_inlined_stack) { 403 Log *log = GetLog(LLDBLog::Step); 404 LLDB_LOGF(log, 405 "ThreadPlanStepOverRange::DoWillResume: adjusting range to " 406 "the frame at inlined depth %d.", 407 thread.GetCurrentInlinedDepth()); 408 StackFrameSP stack_sp = thread.GetStackFrameAtIndex(0); 409 if (stack_sp) { 410 Block *frame_block = stack_sp->GetFrameBlock(); 411 lldb::addr_t curr_pc = thread.GetRegisterContext()->GetPC(); 412 AddressRange my_range; 413 if (frame_block->GetRangeContainingLoadAddress( 414 curr_pc, m_process.GetTarget(), my_range)) { 415 m_address_ranges.clear(); 416 m_address_ranges.push_back(my_range); 417 if (log) { 418 StreamString s; 419 const InlineFunctionInfo *inline_info = 420 frame_block->GetInlinedFunctionInfo(); 421 const char *name; 422 if (inline_info) 423 name = inline_info->GetName().AsCString(); 424 else 425 name = "<unknown-notinlined>"; 426 427 s.Printf( 428 "Stepping over inlined function \"%s\" in inlined stack: ", 429 name); 430 DumpRanges(&s); 431 log->PutString(s.GetString()); 432 } 433 } 434 } 435 } 436 } 437 } 438 if (m_run_mode == lldb::eOnlyThisThread && IsControllingPlan()) 439 ResumeWithTimeout(); 440 return true; 441 } 442