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 // C Includes 11 // C++ Includes 12 // Other libraries and framework includes 13 // Project includes 14 #include "lldb/Target/ThreadPlanStepOverRange.h" 15 #include "lldb/Core/Log.h" 16 #include "lldb/Core/Stream.h" 17 #include "lldb/Symbol/Block.h" 18 #include "lldb/Symbol/CompileUnit.h" 19 #include "lldb/Symbol/Function.h" 20 #include "lldb/Symbol/LineTable.h" 21 #include "lldb/Target/Process.h" 22 #include "lldb/Target/RegisterContext.h" 23 #include "lldb/Target/Target.h" 24 #include "lldb/Target/Thread.h" 25 #include "lldb/Target/ThreadPlanStepOut.h" 26 #include "lldb/Target/ThreadPlanStepThrough.h" 27 28 using namespace lldb_private; 29 using namespace lldb; 30 31 uint32_t ThreadPlanStepOverRange::s_default_flag_values = 0; 32 33 //---------------------------------------------------------------------- 34 // ThreadPlanStepOverRange: Step through a stack range, either stepping over or into 35 // based on the value of \a type. 36 //---------------------------------------------------------------------- 37 38 ThreadPlanStepOverRange::ThreadPlanStepOverRange 39 ( 40 Thread &thread, 41 const AddressRange &range, 42 const SymbolContext &addr_context, 43 lldb::RunMode stop_others, 44 LazyBool step_out_avoids_code_without_debug_info 45 ) : 46 ThreadPlanStepRange (ThreadPlan::eKindStepOverRange, "Step range stepping over", thread, range, addr_context, stop_others), 47 ThreadPlanShouldStopHere (this), 48 m_first_resume(true) 49 { 50 SetFlagsToDefault(); 51 SetupAvoidNoDebug(step_out_avoids_code_without_debug_info); 52 } 53 54 ThreadPlanStepOverRange::~ThreadPlanStepOverRange() = default; 55 56 void 57 ThreadPlanStepOverRange::GetDescription (Stream *s, lldb::DescriptionLevel level) 58 { 59 if (level == lldb::eDescriptionLevelBrief) 60 { 61 s->Printf("step over"); 62 return; 63 } 64 s->Printf ("Stepping over"); 65 bool printed_line_info = false; 66 if (m_addr_context.line_entry.IsValid()) 67 { 68 s->Printf (" line "); 69 m_addr_context.line_entry.DumpStopContext (s, false); 70 printed_line_info = true; 71 } 72 73 if (!printed_line_info || level == eDescriptionLevelVerbose) 74 { 75 s->Printf (" using ranges: "); 76 DumpRanges(s); 77 } 78 79 s->PutChar('.'); 80 } 81 82 void 83 ThreadPlanStepOverRange::SetupAvoidNoDebug(LazyBool step_out_avoids_code_without_debug_info) 84 { 85 bool avoid_nodebug = true; 86 switch (step_out_avoids_code_without_debug_info) 87 { 88 case eLazyBoolYes: 89 avoid_nodebug = true; 90 break; 91 case eLazyBoolNo: 92 avoid_nodebug = false; 93 break; 94 case eLazyBoolCalculate: 95 avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug(); 96 break; 97 } 98 if (avoid_nodebug) 99 GetFlags().Set (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 100 else 101 GetFlags().Clear (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 102 // Step Over plans should always avoid no-debug on step in. Seems like you shouldn't 103 // have to say this, but a tail call looks more like a step in that a step out, so 104 // we want to catch this case. 105 GetFlags().Set (ThreadPlanShouldStopHere::eStepInAvoidNoDebug); 106 } 107 108 bool 109 ThreadPlanStepOverRange::IsEquivalentContext(const SymbolContext &context) 110 { 111 // Match as much as is specified in the m_addr_context: 112 // This is a fairly loose sanity check. Note, sometimes the target doesn't get filled 113 // in so I left out the target check. And sometimes the module comes in as the .o file from the 114 // inlined range, so I left that out too... 115 if (m_addr_context.comp_unit) 116 { 117 if (m_addr_context.comp_unit == context.comp_unit) 118 { 119 if (m_addr_context.function && m_addr_context.function == context.function) 120 { 121 if (m_addr_context.block && m_addr_context.block == context.block) 122 return true; 123 } 124 } 125 } 126 else if (m_addr_context.symbol && m_addr_context.symbol == context.symbol) 127 { 128 return true; 129 } 130 return false; 131 } 132 133 bool 134 ThreadPlanStepOverRange::ShouldStop (Event *event_ptr) 135 { 136 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 137 138 if (log) 139 { 140 StreamString s; 141 s.Address (m_thread.GetRegisterContext()->GetPC(), 142 m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize()); 143 log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData()); 144 } 145 146 // If we're out of the range but in the same frame or in our caller's frame 147 // then we should stop. 148 // When stepping out we only stop others if we are forcing running one thread. 149 bool stop_others = (m_stop_others == lldb::eOnlyThisThread); 150 ThreadPlanSP new_plan_sp; 151 FrameComparison frame_order = CompareCurrentFrameToStartFrame(); 152 153 if (frame_order == eFrameCompareOlder) 154 { 155 // If we're in an older frame then we should stop. 156 // 157 // A caveat to this is if we think the frame is older but we're actually in a trampoline. 158 // I'm going to make the assumption that you wouldn't RETURN to a trampoline. So if we are 159 // in a trampoline we think the frame is older because the trampoline confused the backtracer. 160 // As below, we step through first, and then try to figure out how to get back out again. 161 162 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others); 163 164 if (new_plan_sp && log) 165 log->Printf("Thought I stepped out, but in fact arrived at a trampoline."); 166 } 167 else if (frame_order == eFrameCompareYounger) 168 { 169 // Make sure we really are in a new frame. Do that by unwinding and seeing if the 170 // start function really is our start function... 171 for(uint32_t i = 1;; ++i) 172 { 173 StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(i); 174 if (!older_frame_sp) { 175 // We can't unwind the next frame we should just get out of here & stop... 176 break; 177 } 178 179 const SymbolContext &older_context = older_frame_sp->GetSymbolContext(eSymbolContextEverything); 180 if (IsEquivalentContext(older_context)) 181 { 182 new_plan_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop(false, 183 nullptr, 184 true, 185 stop_others, 186 eVoteNo, 187 eVoteNoOpinion, 188 0); 189 break; 190 } 191 else 192 { 193 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others); 194 // If we found a way through, then we should stop recursing. 195 if (new_plan_sp) 196 break; 197 } 198 } 199 } 200 else 201 { 202 // If we're still in the range, keep going. 203 if (InRange()) 204 { 205 SetNextBranchBreakpoint(); 206 return false; 207 } 208 209 if (!InSymbol()) 210 { 211 // This one is a little tricky. Sometimes we may be in a stub or something similar, 212 // in which case we need to get out of there. But if we are in a stub then it's 213 // likely going to be hard to get out from here. It is probably easiest to step into the 214 // stub, and then it will be straight-forward to step out. 215 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others); 216 } 217 else 218 { 219 // The current clang (at least through 424) doesn't always get the address range for the 220 // DW_TAG_inlined_subroutines right, so that when you leave the inlined range the line table says 221 // you are still in the source file of the inlining function. This is bad, because now you are missing 222 // the stack frame for the function containing the inlining, and if you sensibly do "finish" to get 223 // out of this function you will instead exit the containing function. 224 // To work around this, we check whether we are still in the source file we started in, and if not assume 225 // it is an error, and push a plan to get us out of this line and back to the containing file. 226 227 if (m_addr_context.line_entry.IsValid()) 228 { 229 SymbolContext sc; 230 StackFrameSP frame_sp = m_thread.GetStackFrameAtIndex(0); 231 sc = frame_sp->GetSymbolContext (eSymbolContextEverything); 232 if (sc.line_entry.IsValid()) 233 { 234 if (sc.line_entry.file != m_addr_context.line_entry.file 235 && sc.comp_unit == m_addr_context.comp_unit 236 && sc.function == m_addr_context.function) 237 { 238 // Okay, find the next occurrence of this file in the line table: 239 LineTable *line_table = m_addr_context.comp_unit->GetLineTable(); 240 if (line_table) 241 { 242 Address cur_address = frame_sp->GetFrameCodeAddress(); 243 uint32_t entry_idx; 244 LineEntry line_entry; 245 if (line_table->FindLineEntryByAddress (cur_address, line_entry, &entry_idx)) 246 { 247 LineEntry next_line_entry; 248 bool step_past_remaining_inline = false; 249 if (entry_idx > 0) 250 { 251 // We require the previous line entry and the current line entry come 252 // from the same file. 253 // The other requirement is that the previous line table entry be part of an 254 // inlined block, we don't want to step past cases where people have inlined 255 // some code fragment by using #include <source-fragment.c> directly. 256 LineEntry prev_line_entry; 257 if (line_table->GetLineEntryAtIndex(entry_idx - 1, prev_line_entry) 258 && prev_line_entry.file == line_entry.file) 259 { 260 SymbolContext prev_sc; 261 Address prev_address = prev_line_entry.range.GetBaseAddress(); 262 prev_address.CalculateSymbolContext(&prev_sc); 263 if (prev_sc.block) 264 { 265 Block *inlined_block = prev_sc.block->GetContainingInlinedBlock(); 266 if (inlined_block) 267 { 268 AddressRange inline_range; 269 inlined_block->GetRangeContainingAddress(prev_address, inline_range); 270 if (!inline_range.ContainsFileAddress(cur_address)) 271 { 272 273 step_past_remaining_inline = true; 274 } 275 } 276 } 277 } 278 } 279 280 if (step_past_remaining_inline) 281 { 282 uint32_t look_ahead_step = 1; 283 while (line_table->GetLineEntryAtIndex(entry_idx + look_ahead_step, next_line_entry)) 284 { 285 // Make sure we haven't wandered out of the function we started from... 286 Address next_line_address = next_line_entry.range.GetBaseAddress(); 287 Function *next_line_function = next_line_address.CalculateSymbolContextFunction(); 288 if (next_line_function != m_addr_context.function) 289 break; 290 291 if (next_line_entry.file == m_addr_context.line_entry.file) 292 { 293 const bool abort_other_plans = false; 294 const RunMode stop_other_threads = RunMode::eAllThreads; 295 lldb::addr_t cur_pc = m_thread.GetStackFrameAtIndex(0)->GetRegisterContext()->GetPC(); 296 AddressRange step_range(cur_pc, next_line_address.GetLoadAddress(&GetTarget()) - cur_pc); 297 298 new_plan_sp = m_thread.QueueThreadPlanForStepOverRange (abort_other_plans, 299 step_range, 300 sc, 301 stop_other_threads); 302 break; 303 } 304 look_ahead_step++; 305 } 306 } 307 } 308 } 309 } 310 } 311 } 312 } 313 } 314 315 // If we get to this point, we're not going to use a previously set "next branch" breakpoint, so delete it: 316 ClearNextBranchBreakpoint(); 317 318 319 // If we haven't figured out something to do yet, then ask the ShouldStopHere callback: 320 if (!new_plan_sp) 321 { 322 new_plan_sp = CheckShouldStopHereAndQueueStepOut (frame_order); 323 } 324 325 if (!new_plan_sp) 326 m_no_more_plans = true; 327 else 328 { 329 // Any new plan will be an implementation plan, so mark it private: 330 new_plan_sp->SetPrivate(true); 331 m_no_more_plans = false; 332 } 333 334 if (!new_plan_sp) 335 { 336 // For efficiencies sake, we know we're done here so we don't have to do this 337 // calculation again in MischiefManaged. 338 SetPlanComplete(); 339 return true; 340 } 341 else 342 return false; 343 } 344 345 bool 346 ThreadPlanStepOverRange::DoPlanExplainsStop (Event *event_ptr) 347 { 348 // For crashes, breakpoint hits, signals, etc, let the base plan (or some plan above us) 349 // handle the stop. That way the user can see the stop, step around, and then when they 350 // are done, continue and have their step complete. The exception is if we've hit our 351 // "run to next branch" breakpoint. 352 // Note, unlike the step in range plan, we don't mark ourselves complete if we hit an 353 // unexplained breakpoint/crash. 354 355 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 356 StopInfoSP stop_info_sp = GetPrivateStopInfo (); 357 bool return_value; 358 359 if (stop_info_sp) 360 { 361 StopReason reason = stop_info_sp->GetStopReason(); 362 363 if (reason == eStopReasonTrace) 364 { 365 return_value = true; 366 } 367 else if (reason == eStopReasonBreakpoint) 368 { 369 return_value = NextRangeBreakpointExplainsStop(stop_info_sp); 370 } 371 else 372 { 373 if (log) 374 log->PutCString ("ThreadPlanStepInRange got asked if it explains the stop for some reason other than step."); 375 return_value = false; 376 } 377 } 378 else 379 return_value = true; 380 381 return return_value; 382 } 383 384 bool 385 ThreadPlanStepOverRange::DoWillResume (lldb::StateType resume_state, bool current_plan) 386 { 387 if (resume_state != eStateSuspended && m_first_resume) 388 { 389 m_first_resume = false; 390 if (resume_state == eStateStepping && current_plan) 391 { 392 // See if we are about to step over an inlined call in the middle of the inlined stack, if so figure 393 // out its extents and reset our range to step over that. 394 bool in_inlined_stack = m_thread.DecrementCurrentInlinedDepth(); 395 if (in_inlined_stack) 396 { 397 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 398 if (log) 399 log->Printf ("ThreadPlanStepInRange::DoWillResume: adjusting range to the frame at inlined depth %d.", 400 m_thread.GetCurrentInlinedDepth()); 401 StackFrameSP stack_sp = m_thread.GetStackFrameAtIndex(0); 402 if (stack_sp) 403 { 404 Block *frame_block = stack_sp->GetFrameBlock(); 405 lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC(); 406 AddressRange my_range; 407 if (frame_block->GetRangeContainingLoadAddress(curr_pc, m_thread.GetProcess()->GetTarget(), my_range)) 408 { 409 m_address_ranges.clear(); 410 m_address_ranges.push_back(my_range); 411 if (log) 412 { 413 StreamString s; 414 const InlineFunctionInfo *inline_info = frame_block->GetInlinedFunctionInfo(); 415 const char *name; 416 if (inline_info) 417 name = inline_info->GetName(frame_block->CalculateSymbolContextFunction()->GetLanguage()).AsCString(); 418 else 419 name = "<unknown-notinlined>"; 420 421 s.Printf ("Stepping over inlined function \"%s\" in inlined stack: ", name); 422 DumpRanges(&s); 423 log->PutCString(s.GetData()); 424 } 425 } 426 427 } 428 } 429 } 430 } 431 432 return true; 433 } 434