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