1 //===-- ThreadPlanStepRange.cpp -------------------------------------------===//
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
7 //===----------------------------------------------------------------------===//
9 #include "lldb/Target/ThreadPlanStepRange.h"
10 #include "lldb/Breakpoint/BreakpointLocation.h"
11 #include "lldb/Breakpoint/BreakpointSite.h"
12 #include "lldb/Core/Disassembler.h"
13 #include "lldb/Symbol/Function.h"
14 #include "lldb/Symbol/Symbol.h"
15 #include "lldb/Target/ExecutionContext.h"
16 #include "lldb/Target/Process.h"
17 #include "lldb/Target/RegisterContext.h"
18 #include "lldb/Target/StopInfo.h"
19 #include "lldb/Target/Target.h"
20 #include "lldb/Target/Thread.h"
21 #include "lldb/Target/ThreadPlanRunToAddress.h"
22 #include "lldb/Utility/Log.h"
23 #include "lldb/Utility/Stream.h"
26 using namespace lldb_private;
28 // ThreadPlanStepRange: Step through a stack range, either stepping over or
29 // into based on the value of \a type.
31 ThreadPlanStepRange::ThreadPlanStepRange(ThreadPlanKind kind, const char *name,
33 const AddressRange &range,
34 const SymbolContext &addr_context,
35 lldb::RunMode stop_others,
36 bool given_ranges_only)
37 : ThreadPlan(kind, name, thread, eVoteNoOpinion, eVoteNoOpinion),
38 m_addr_context(addr_context), m_address_ranges(),
39 m_stop_others(stop_others), m_stack_id(), m_parent_stack_id(),
40 m_no_more_plans(false), m_first_run_event(true), m_use_fast_step(false),
41 m_given_ranges_only(given_ranges_only) {
42 m_use_fast_step = GetTarget().GetUseFastStepping();
44 m_stack_id = thread.GetStackFrameAtIndex(0)->GetStackID();
45 StackFrameSP parent_stack = thread.GetStackFrameAtIndex(1);
47 m_parent_stack_id = parent_stack->GetStackID();
50 ThreadPlanStepRange::~ThreadPlanStepRange() { ClearNextBranchBreakpoint(); }
52 void ThreadPlanStepRange::DidPush() {
53 // See if we can find a "next range" breakpoint:
54 SetNextBranchBreakpoint();
57 bool ThreadPlanStepRange::ValidatePlan(Stream *error) {
58 if (m_could_not_resolve_hw_bp) {
61 "Could not create hardware breakpoint for thread plan.");
67 Vote ThreadPlanStepRange::ShouldReportStop(Event *event_ptr) {
68 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
70 const Vote vote = IsPlanComplete() ? eVoteYes : eVoteNo;
71 LLDB_LOGF(log, "ThreadPlanStepRange::ShouldReportStop() returning vote %i\n",
76 void ThreadPlanStepRange::AddRange(const AddressRange &new_range) {
77 // For now I'm just adding the ranges. At some point we may want to condense
78 // the ranges if they overlap, though I don't think it is likely to be very
80 m_address_ranges.push_back(new_range);
82 // Fill the slot for this address range with an empty DisassemblerSP in the
83 // instruction ranges. I want the indices to match, but I don't want to do
84 // the work to disassemble this range if I don't step into it.
85 m_instruction_ranges.push_back(DisassemblerSP());
88 void ThreadPlanStepRange::DumpRanges(Stream *s) {
89 size_t num_ranges = m_address_ranges.size();
90 if (num_ranges == 1) {
91 m_address_ranges[0].Dump(s, &GetTarget(), Address::DumpStyleLoadAddress);
93 for (size_t i = 0; i < num_ranges; i++) {
94 s->Printf(" %" PRIu64 ": ", uint64_t(i));
95 m_address_ranges[i].Dump(s, &GetTarget(), Address::DumpStyleLoadAddress);
100 bool ThreadPlanStepRange::InRange() {
101 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
102 bool ret_value = false;
103 Thread &thread = GetThread();
104 lldb::addr_t pc_load_addr = thread.GetRegisterContext()->GetPC();
106 size_t num_ranges = m_address_ranges.size();
107 for (size_t i = 0; i < num_ranges; i++) {
109 m_address_ranges[i].ContainsLoadAddress(pc_load_addr, &GetTarget());
114 if (!ret_value && !m_given_ranges_only) {
115 // See if we've just stepped to another part of the same line number...
116 StackFrame *frame = thread.GetStackFrameAtIndex(0).get();
118 SymbolContext new_context(
119 frame->GetSymbolContext(eSymbolContextEverything));
120 if (m_addr_context.line_entry.IsValid() &&
121 new_context.line_entry.IsValid()) {
122 if (m_addr_context.line_entry.original_file ==
123 new_context.line_entry.original_file) {
124 if (m_addr_context.line_entry.line == new_context.line_entry.line) {
125 m_addr_context = new_context;
126 const bool include_inlined_functions =
127 GetKind() == eKindStepOverRange;
128 AddRange(m_addr_context.line_entry.GetSameLineContiguousAddressRange(
129 include_inlined_functions));
133 m_addr_context.line_entry.Dump(&s, &GetTarget(), true,
134 Address::DumpStyleLoadAddress,
135 Address::DumpStyleLoadAddress, true);
139 "Step range plan stepped to another range of same line: %s",
142 } else if (new_context.line_entry.line == 0) {
143 new_context.line_entry.line = m_addr_context.line_entry.line;
144 m_addr_context = new_context;
145 const bool include_inlined_functions =
146 GetKind() == eKindStepOverRange;
147 AddRange(m_addr_context.line_entry.GetSameLineContiguousAddressRange(
148 include_inlined_functions));
152 m_addr_context.line_entry.Dump(&s, &GetTarget(), true,
153 Address::DumpStyleLoadAddress,
154 Address::DumpStyleLoadAddress, true);
157 "Step range plan stepped to a range at linenumber 0 "
158 "stepping through that range: %s",
161 } else if (new_context.line_entry.range.GetBaseAddress().GetLoadAddress(
162 &GetTarget()) != pc_load_addr) {
163 // Another thing that sometimes happens here is that we step out of
164 // one line into the MIDDLE of another line. So far I mostly see
165 // this due to bugs in the debug information. But we probably don't
166 // want to be in the middle of a line range, so in that case reset
167 // the stepping range to the line we've stepped into the middle of
169 m_addr_context = new_context;
170 m_address_ranges.clear();
171 AddRange(m_addr_context.line_entry.range);
175 m_addr_context.line_entry.Dump(&s, &GetTarget(), true,
176 Address::DumpStyleLoadAddress,
177 Address::DumpStyleLoadAddress, true);
180 "Step range plan stepped to the middle of new "
181 "line(%d): %s, continuing to clear this line.",
182 new_context.line_entry.line, s.GetData());
189 if (!ret_value && log)
190 LLDB_LOGF(log, "Step range plan out of range to 0x%" PRIx64, pc_load_addr);
195 bool ThreadPlanStepRange::InSymbol() {
196 lldb::addr_t cur_pc = GetThread().GetRegisterContext()->GetPC();
197 if (m_addr_context.function != nullptr) {
198 return m_addr_context.function->GetAddressRange().ContainsLoadAddress(
199 cur_pc, &GetTarget());
200 } else if (m_addr_context.symbol && m_addr_context.symbol->ValueIsAddress()) {
201 AddressRange range(m_addr_context.symbol->GetAddressRef(),
202 m_addr_context.symbol->GetByteSize());
203 return range.ContainsLoadAddress(cur_pc, &GetTarget());
208 // FIXME: This should also handle inlining if we aren't going to do inlining in
212 // Ideally we should remember the whole stack frame list, and then compare that
213 // to the current list.
215 lldb::FrameComparison ThreadPlanStepRange::CompareCurrentFrameToStartFrame() {
216 FrameComparison frame_order;
217 Thread &thread = GetThread();
218 StackID cur_frame_id = thread.GetStackFrameAtIndex(0)->GetStackID();
220 if (cur_frame_id == m_stack_id) {
221 frame_order = eFrameCompareEqual;
222 } else if (cur_frame_id < m_stack_id) {
223 frame_order = eFrameCompareYounger;
225 StackFrameSP cur_parent_frame = thread.GetStackFrameAtIndex(1);
226 StackID cur_parent_id;
227 if (cur_parent_frame)
228 cur_parent_id = cur_parent_frame->GetStackID();
229 if (m_parent_stack_id.IsValid() && cur_parent_id.IsValid() &&
230 m_parent_stack_id == cur_parent_id)
231 frame_order = eFrameCompareSameParent;
233 frame_order = eFrameCompareOlder;
238 bool ThreadPlanStepRange::StopOthers() {
239 switch (m_stop_others) {
240 case lldb::eOnlyThisThread:
242 case lldb::eOnlyDuringStepping:
243 // If there is a call in the range of the next branch breakpoint,
244 // then we should always run all threads, since a call can execute
245 // arbitrary code which might for instance take a lock that's held
246 // by another thread.
247 return !m_found_calls;
248 case lldb::eAllThreads:
251 llvm_unreachable("Unhandled run mode!");
254 InstructionList *ThreadPlanStepRange::GetInstructionsForAddress(
255 lldb::addr_t addr, size_t &range_index, size_t &insn_offset) {
256 size_t num_ranges = m_address_ranges.size();
257 for (size_t i = 0; i < num_ranges; i++) {
258 if (m_address_ranges[i].ContainsLoadAddress(addr, &GetTarget())) {
259 // Some joker added a zero size range to the stepping range...
260 if (m_address_ranges[i].GetByteSize() == 0)
263 if (!m_instruction_ranges[i]) {
264 // Disassemble the address range given:
265 const char *plugin_name = nullptr;
266 const char *flavor = nullptr;
267 const bool prefer_file_cache = true;
268 m_instruction_ranges[i] = Disassembler::DisassembleRange(
269 GetTarget().GetArchitecture(), plugin_name, flavor, GetTarget(),
270 m_address_ranges[i], prefer_file_cache);
272 if (!m_instruction_ranges[i])
275 // Find where we are in the instruction list as well. If we aren't at
276 // an instruction, return nullptr. In this case, we're probably lost,
277 // and shouldn't try to do anything fancy.
280 m_instruction_ranges[i]
281 ->GetInstructionList()
282 .GetIndexOfInstructionAtLoadAddress(addr, GetTarget());
283 if (insn_offset == UINT32_MAX)
287 return &m_instruction_ranges[i]->GetInstructionList();
295 void ThreadPlanStepRange::ClearNextBranchBreakpoint() {
296 if (m_next_branch_bp_sp) {
297 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
298 LLDB_LOGF(log, "Removing next branch breakpoint: %d.",
299 m_next_branch_bp_sp->GetID());
300 GetTarget().RemoveBreakpointByID(m_next_branch_bp_sp->GetID());
301 m_next_branch_bp_sp.reset();
302 m_could_not_resolve_hw_bp = false;
303 m_found_calls = false;
307 bool ThreadPlanStepRange::SetNextBranchBreakpoint() {
308 if (m_next_branch_bp_sp)
311 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
312 // Stepping through ranges using breakpoints doesn't work yet, but with this
313 // off we fall back to instruction single stepping.
314 if (!m_use_fast_step)
317 // clear the m_found_calls, we'll rediscover it for this range.
318 m_found_calls = false;
320 lldb::addr_t cur_addr = GetThread().GetRegisterContext()->GetPC();
321 // Find the current address in our address ranges, and fetch the disassembly
322 // if we haven't already:
325 InstructionList *instructions =
326 GetInstructionsForAddress(cur_addr, range_index, pc_index);
327 if (instructions == nullptr)
330 Target &target = GetThread().GetProcess()->GetTarget();
331 const bool ignore_calls = GetKind() == eKindStepOverRange;
332 uint32_t branch_index =
333 instructions->GetIndexOfNextBranchInstruction(pc_index, target,
337 Address run_to_address;
339 // If we didn't find a branch, run to the end of the range.
340 if (branch_index == UINT32_MAX) {
341 uint32_t last_index = instructions->GetSize() - 1;
342 if (last_index - pc_index > 1) {
343 InstructionSP last_inst =
344 instructions->GetInstructionAtIndex(last_index);
345 size_t last_inst_size = last_inst->GetOpcode().GetByteSize();
346 run_to_address = last_inst->GetAddress();
347 run_to_address.Slide(last_inst_size);
349 } else if (branch_index - pc_index > 1) {
351 instructions->GetInstructionAtIndex(branch_index)->GetAddress();
354 if (run_to_address.IsValid()) {
355 const bool is_internal = true;
356 m_next_branch_bp_sp =
357 GetTarget().CreateBreakpoint(run_to_address, is_internal, false);
358 if (m_next_branch_bp_sp) {
360 if (m_next_branch_bp_sp->IsHardware() &&
361 !m_next_branch_bp_sp->HasResolvedLocations())
362 m_could_not_resolve_hw_bp = true;
365 lldb::break_id_t bp_site_id = LLDB_INVALID_BREAK_ID;
366 BreakpointLocationSP bp_loc =
367 m_next_branch_bp_sp->GetLocationAtIndex(0);
369 BreakpointSiteSP bp_site = bp_loc->GetBreakpointSite();
371 bp_site_id = bp_site->GetID();
375 "ThreadPlanStepRange::SetNextBranchBreakpoint - Setting "
376 "breakpoint %d (site %d) to run to address 0x%" PRIx64,
377 m_next_branch_bp_sp->GetID(), bp_site_id,
378 run_to_address.GetLoadAddress(&m_process.GetTarget()));
381 m_next_branch_bp_sp->SetThreadID(m_tid);
382 m_next_branch_bp_sp->SetBreakpointKind("next-branch-location");
392 bool ThreadPlanStepRange::NextRangeBreakpointExplainsStop(
393 lldb::StopInfoSP stop_info_sp) {
394 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
395 if (!m_next_branch_bp_sp)
398 break_id_t bp_site_id = stop_info_sp->GetValue();
399 BreakpointSiteSP bp_site_sp =
400 m_process.GetBreakpointSiteList().FindByID(bp_site_id);
403 else if (!bp_site_sp->IsBreakpointAtThisSite(m_next_branch_bp_sp->GetID()))
406 // If we've hit the next branch breakpoint, then clear it.
407 size_t num_owners = bp_site_sp->GetNumberOfOwners();
408 bool explains_stop = true;
409 // If all the owners are internal, then we are probably just stepping over
410 // this range from multiple threads, or multiple frames, so we want to
411 // continue. If one is not internal, then we should not explain the stop,
412 // and let the user breakpoint handle the stop.
413 for (size_t i = 0; i < num_owners; i++) {
414 if (!bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint().IsInternal()) {
415 explains_stop = false;
420 "ThreadPlanStepRange::NextRangeBreakpointExplainsStop - Hit "
421 "next range breakpoint which has %" PRIu64
422 " owners - explains stop: %u.",
423 (uint64_t)num_owners, explains_stop);
424 ClearNextBranchBreakpoint();
425 return explains_stop;
429 bool ThreadPlanStepRange::WillStop() { return true; }
431 StateType ThreadPlanStepRange::GetPlanRunState() {
432 if (m_next_branch_bp_sp)
433 return eStateRunning;
435 return eStateStepping;
438 bool ThreadPlanStepRange::MischiefManaged() {
439 // If we have pushed some plans between ShouldStop & MischiefManaged, then
441 // I do this check first because we might have stepped somewhere that will
443 // thinking it needs to step past the end of that line. This happens, for
444 // instance, when stepping over inlined code that is in the middle of the
447 if (!m_no_more_plans)
451 if (!IsPlanComplete()) {
455 FrameComparison frame_order = CompareCurrentFrameToStartFrame();
456 done = (frame_order != eFrameCompareOlder) ? m_no_more_plans : true;
461 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
462 LLDB_LOGF(log, "Completed step through range plan.");
463 ClearNextBranchBreakpoint();
464 ThreadPlan::MischiefManaged();
471 bool ThreadPlanStepRange::IsPlanStale() {
472 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
473 FrameComparison frame_order = CompareCurrentFrameToStartFrame();
475 if (frame_order == eFrameCompareOlder) {
477 LLDB_LOGF(log, "ThreadPlanStepRange::IsPlanStale returning true, we've "
481 } else if (frame_order == eFrameCompareEqual && InSymbol()) {
482 // If we are not in a place we should step through, we've gotten stale. One
483 // tricky bit here is that some stubs don't push a frame, so we should.
484 // check that we are in the same symbol.
486 // Set plan Complete when we reach next instruction just after the range
487 lldb::addr_t addr = GetThread().GetRegisterContext()->GetPC() - 1;
488 size_t num_ranges = m_address_ranges.size();
489 for (size_t i = 0; i < num_ranges; i++) {
491 m_address_ranges[i].ContainsLoadAddress(addr, &GetTarget());