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