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 #include "lldb/Target/ThreadPlanStepOverRange.h" 11 12 // C Includes 13 // C++ Includes 14 // Other libraries and framework includes 15 // Project includes 16 #include "lldb/Core/Log.h" 17 #include "lldb/Core/Stream.h" 18 #include "lldb/Symbol/Block.h" 19 #include "lldb/Symbol/CompileUnit.h" 20 #include "lldb/Symbol/Function.h" 21 #include "lldb/Symbol/LineTable.h" 22 #include "lldb/Target/Process.h" 23 #include "lldb/Target/RegisterContext.h" 24 #include "lldb/Target/Target.h" 25 #include "lldb/Target/Thread.h" 26 #include "lldb/Target/ThreadPlanStepOut.h" 27 #include "lldb/Target/ThreadPlanStepThrough.h" 28 29 using namespace lldb_private; 30 using namespace lldb; 31 32 uint32_t ThreadPlanStepOverRange::s_default_flag_values = 0; 33 34 //---------------------------------------------------------------------- 35 // ThreadPlanStepOverRange: Step through a stack range, either stepping over or into 36 // based on the value of \a type. 37 //---------------------------------------------------------------------- 38 39 ThreadPlanStepOverRange::ThreadPlanStepOverRange 40 ( 41 Thread &thread, 42 const AddressRange &range, 43 const SymbolContext &addr_context, 44 lldb::RunMode stop_others, 45 LazyBool step_out_avoids_code_without_debug_info 46 ) : 47 ThreadPlanStepRange (ThreadPlan::eKindStepOverRange, "Step range stepping over", thread, range, addr_context, stop_others), 48 ThreadPlanShouldStopHere (this), 49 m_first_resume(true) 50 { 51 SetFlagsToDefault(); 52 SetupAvoidNoDebug(step_out_avoids_code_without_debug_info); 53 } 54 55 ThreadPlanStepOverRange::~ThreadPlanStepOverRange () 56 { 57 } 58 59 void 60 ThreadPlanStepOverRange::GetDescription (Stream *s, lldb::DescriptionLevel level) 61 { 62 if (level == lldb::eDescriptionLevelBrief) 63 { 64 s->Printf("step over"); 65 return; 66 } 67 s->Printf ("Stepping over"); 68 bool printed_line_info = false; 69 if (m_addr_context.line_entry.IsValid()) 70 { 71 s->Printf (" line "); 72 m_addr_context.line_entry.DumpStopContext (s, false); 73 printed_line_info = true; 74 } 75 76 if (!printed_line_info || level == eDescriptionLevelVerbose) 77 { 78 s->Printf (" using ranges: "); 79 DumpRanges(s); 80 } 81 82 s->PutChar('.'); 83 } 84 85 void 86 ThreadPlanStepOverRange::SetupAvoidNoDebug(LazyBool step_out_avoids_code_without_debug_info) 87 { 88 bool avoid_nodebug = true; 89 switch (step_out_avoids_code_without_debug_info) 90 { 91 case eLazyBoolYes: 92 avoid_nodebug = true; 93 break; 94 case eLazyBoolNo: 95 avoid_nodebug = false; 96 break; 97 case eLazyBoolCalculate: 98 avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug(); 99 break; 100 } 101 if (avoid_nodebug) 102 GetFlags().Set (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 103 else 104 GetFlags().Clear (ThreadPlanShouldStopHere::eStepOutAvoidNoDebug); 105 // Step Over plans should always avoid no-debug on step in. Seems like you shouldn't 106 // have to say this, but a tail call looks more like a step in that a step out, so 107 // we want to catch this case. 108 GetFlags().Set (ThreadPlanShouldStopHere::eStepInAvoidNoDebug); 109 } 110 111 bool 112 ThreadPlanStepOverRange::IsEquivalentContext(const SymbolContext &context) 113 { 114 115 // Match as much as is specified in the m_addr_context: 116 // This is a fairly loose sanity check. Note, sometimes the target doesn't get filled 117 // in so I left out the target check. And sometimes the module comes in as the .o file from the 118 // inlined range, so I left that out too... 119 if (m_addr_context.comp_unit) 120 { 121 if (m_addr_context.comp_unit == context.comp_unit) 122 { 123 if (m_addr_context.function && m_addr_context.function == context.function) 124 { 125 if (m_addr_context.block && m_addr_context.block == context.block) 126 return true; 127 } 128 } 129 } 130 else if (m_addr_context.symbol && m_addr_context.symbol == context.symbol) 131 { 132 return true; 133 } 134 return false; 135 } 136 137 bool 138 ThreadPlanStepOverRange::ShouldStop (Event *event_ptr) 139 { 140 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 141 142 if (log) 143 { 144 StreamString s; 145 s.Address (m_thread.GetRegisterContext()->GetPC(), 146 m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize()); 147 log->Printf("ThreadPlanStepOverRange reached %s.", s.GetData()); 148 } 149 150 // If we're out of the range but in the same frame or in our caller's frame 151 // then we should stop. 152 // When stepping out we only stop others if we are forcing running one thread. 153 bool stop_others; 154 if (m_stop_others == lldb::eOnlyThisThread) 155 stop_others = true; 156 else 157 stop_others = false; 158 159 ThreadPlanSP new_plan_sp; 160 161 FrameComparison frame_order = CompareCurrentFrameToStartFrame(); 162 163 if (frame_order == eFrameCompareOlder) 164 { 165 // If we're in an older frame then we should stop. 166 // 167 // A caveat to this is if we think the frame is older but we're actually in a trampoline. 168 // I'm going to make the assumption that you wouldn't RETURN to a trampoline. So if we are 169 // in a trampoline we think the frame is older because the trampoline confused the backtracer. 170 // As below, we step through first, and then try to figure out how to get back out again. 171 172 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others); 173 174 if (new_plan_sp && log) 175 log->Printf("Thought I stepped out, but in fact arrived at a trampoline."); 176 } 177 else if (frame_order == eFrameCompareYounger) 178 { 179 // Make sure we really are in a new frame. Do that by unwinding and seeing if the 180 // start function really is our start function... 181 for(uint32_t i = 1;; ++i) 182 { 183 StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(i); 184 if (!older_frame_sp) { 185 // We can't unwind the next frame we should just get out of here & stop... 186 break; 187 } 188 189 const SymbolContext &older_context = older_frame_sp->GetSymbolContext(eSymbolContextEverything); 190 if (IsEquivalentContext(older_context)) 191 { 192 new_plan_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop (false, 193 NULL, 194 true, 195 stop_others, 196 eVoteNo, 197 eVoteNoOpinion, 198 0); 199 break; 200 } 201 else 202 { 203 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others); 204 // If we found a way through, then we should stop recursing. 205 if (new_plan_sp) 206 break; 207 } 208 } 209 } 210 else 211 { 212 // If we're still in the range, keep going. 213 if (InRange()) 214 { 215 SetNextBranchBreakpoint(); 216 return false; 217 } 218 219 220 if (!InSymbol()) 221 { 222 // This one is a little tricky. Sometimes we may be in a stub or something similar, 223 // in which case we need to get out of there. But if we are in a stub then it's 224 // likely going to be hard to get out from here. It is probably easiest to step into the 225 // stub, and then it will be straight-forward to step out. 226 new_plan_sp = m_thread.QueueThreadPlanForStepThrough (m_stack_id, false, stop_others); 227 } 228 else 229 { 230 // The current clang (at least through 424) doesn't always get the address range for the 231 // DW_TAG_inlined_subroutines right, so that when you leave the inlined range the line table says 232 // you are still in the source file of the inlining function. This is bad, because now you are missing 233 // the stack frame for the function containing the inlining, and if you sensibly do "finish" to get 234 // out of this function you will instead exit the containing function. 235 // To work around this, we check whether we are still in the source file we started in, and if not assume 236 // it is an error, and push a plan to get us out of this line and back to the containing file. 237 238 if (m_addr_context.line_entry.IsValid()) 239 { 240 SymbolContext sc; 241 StackFrameSP frame_sp = m_thread.GetStackFrameAtIndex(0); 242 sc = frame_sp->GetSymbolContext (eSymbolContextEverything); 243 if (sc.line_entry.IsValid()) 244 { 245 if (sc.line_entry.file != m_addr_context.line_entry.file 246 && sc.comp_unit == m_addr_context.comp_unit 247 && sc.function == m_addr_context.function) 248 { 249 // Okay, find the next occurrence of this file in the line table: 250 LineTable *line_table = m_addr_context.comp_unit->GetLineTable(); 251 if (line_table) 252 { 253 Address cur_address = frame_sp->GetFrameCodeAddress(); 254 uint32_t entry_idx; 255 LineEntry line_entry; 256 if (line_table->FindLineEntryByAddress (cur_address, line_entry, &entry_idx)) 257 { 258 LineEntry next_line_entry; 259 bool step_past_remaining_inline = false; 260 if (entry_idx > 0) 261 { 262 // We require the previous line entry and the current line entry come 263 // from the same file. 264 // The other requirement is that the previous line table entry be part of an 265 // inlined block, we don't want to step past cases where people have inlined 266 // some code fragment by using #include <source-fragment.c> directly. 267 LineEntry prev_line_entry; 268 if (line_table->GetLineEntryAtIndex(entry_idx - 1, prev_line_entry) 269 && prev_line_entry.file == line_entry.file) 270 { 271 SymbolContext prev_sc; 272 Address prev_address = prev_line_entry.range.GetBaseAddress(); 273 prev_address.CalculateSymbolContext(&prev_sc); 274 if (prev_sc.block) 275 { 276 Block *inlined_block = prev_sc.block->GetContainingInlinedBlock(); 277 if (inlined_block) 278 { 279 AddressRange inline_range; 280 inlined_block->GetRangeContainingAddress(prev_address, inline_range); 281 if (!inline_range.ContainsFileAddress(cur_address)) 282 { 283 284 step_past_remaining_inline = true; 285 } 286 287 } 288 } 289 } 290 } 291 292 if (step_past_remaining_inline) 293 { 294 uint32_t look_ahead_step = 1; 295 while (line_table->GetLineEntryAtIndex(entry_idx + look_ahead_step, next_line_entry)) 296 { 297 // Make sure we haven't wandered out of the function we started from... 298 Address next_line_address = next_line_entry.range.GetBaseAddress(); 299 Function *next_line_function = next_line_address.CalculateSymbolContextFunction(); 300 if (next_line_function != m_addr_context.function) 301 break; 302 303 if (next_line_entry.file == m_addr_context.line_entry.file) 304 { 305 const bool abort_other_plans = false; 306 const bool stop_other_threads = false; 307 new_plan_sp = m_thread.QueueThreadPlanForRunToAddress(abort_other_plans, 308 next_line_address, 309 stop_other_threads); 310 break; 311 } 312 look_ahead_step++; 313 } 314 } 315 } 316 } 317 } 318 } 319 } 320 } 321 } 322 323 // If we get to this point, we're not going to use a previously set "next branch" breakpoint, so delete it: 324 ClearNextBranchBreakpoint(); 325 326 327 // If we haven't figured out something to do yet, then ask the ShouldStopHere callback: 328 if (!new_plan_sp) 329 { 330 new_plan_sp = CheckShouldStopHereAndQueueStepOut (frame_order); 331 } 332 333 if (!new_plan_sp) 334 m_no_more_plans = true; 335 else 336 { 337 // Any new plan will be an implementation plan, so mark it private: 338 new_plan_sp->SetPrivate(true); 339 m_no_more_plans = false; 340 } 341 342 if (!new_plan_sp) 343 { 344 // For efficiencies sake, we know we're done here so we don't have to do this 345 // calculation again in MischiefManaged. 346 SetPlanComplete(); 347 return true; 348 } 349 else 350 return false; 351 } 352 353 bool 354 ThreadPlanStepOverRange::DoPlanExplainsStop (Event *event_ptr) 355 { 356 // For crashes, breakpoint hits, signals, etc, let the base plan (or some plan above us) 357 // handle the stop. That way the user can see the stop, step around, and then when they 358 // are done, continue and have their step complete. The exception is if we've hit our 359 // "run to next branch" breakpoint. 360 // Note, unlike the step in range plan, we don't mark ourselves complete if we hit an 361 // unexplained breakpoint/crash. 362 363 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 364 StopInfoSP stop_info_sp = GetPrivateStopInfo (); 365 bool return_value; 366 367 if (stop_info_sp) 368 { 369 StopReason reason = stop_info_sp->GetStopReason(); 370 371 switch (reason) 372 { 373 case eStopReasonTrace: 374 return_value = true; 375 break; 376 case eStopReasonBreakpoint: 377 if (NextRangeBreakpointExplainsStop(stop_info_sp)) 378 return_value = true; 379 else 380 return_value = false; 381 break; 382 case eStopReasonWatchpoint: 383 case eStopReasonSignal: 384 case eStopReasonException: 385 case eStopReasonExec: 386 case eStopReasonThreadExiting: 387 default: 388 if (log) 389 log->PutCString ("ThreadPlanStepInRange got asked if it explains the stop for some reason other than step."); 390 return_value = false; 391 break; 392 } 393 } 394 else 395 return_value = true; 396 397 return return_value; 398 } 399 400 bool 401 ThreadPlanStepOverRange::DoWillResume (lldb::StateType resume_state, bool current_plan) 402 { 403 if (resume_state != eStateSuspended && m_first_resume) 404 { 405 m_first_resume = false; 406 if (resume_state == eStateStepping && current_plan) 407 { 408 // See if we are about to step over an inlined call in the middle of the inlined stack, if so figure 409 // out its extents and reset our range to step over that. 410 bool in_inlined_stack = m_thread.DecrementCurrentInlinedDepth(); 411 if (in_inlined_stack) 412 { 413 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); 414 if (log) 415 log->Printf ("ThreadPlanStepInRange::DoWillResume: adjusting range to the frame at inlined depth %d.", 416 m_thread.GetCurrentInlinedDepth()); 417 StackFrameSP stack_sp = m_thread.GetStackFrameAtIndex(0); 418 if (stack_sp) 419 { 420 Block *frame_block = stack_sp->GetFrameBlock(); 421 lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC(); 422 AddressRange my_range; 423 if (frame_block->GetRangeContainingLoadAddress(curr_pc, m_thread.GetProcess()->GetTarget(), my_range)) 424 { 425 m_address_ranges.clear(); 426 m_address_ranges.push_back(my_range); 427 if (log) 428 { 429 StreamString s; 430 const InlineFunctionInfo *inline_info = frame_block->GetInlinedFunctionInfo(); 431 const char *name; 432 if (inline_info) 433 name = inline_info->GetName(frame_block->CalculateSymbolContextFunction()->GetLanguage()).AsCString(); 434 else 435 name = "<unknown-notinlined>"; 436 437 s.Printf ("Stepping over inlined function \"%s\" in inlined stack: ", name); 438 DumpRanges(&s); 439 log->PutCString(s.GetData()); 440 } 441 } 442 443 } 444 } 445 } 446 } 447 448 return true; 449 } 450 451