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