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authorpatrick <patrick@openbsd.org>2020-08-03 14:33:06 +0000
committerpatrick <patrick@openbsd.org>2020-08-03 14:33:06 +0000
commit061da546b983eb767bad15e67af1174fb0bcf31c (patch)
tree83c78b820819d70aa40c36d90447978b300078c5 /gnu/llvm/lldb/source/Target/ThreadPlanStepOut.cpp
parentImport LLVM 10.0.0 release including clang, lld and lldb. (diff)
downloadwireguard-openbsd-061da546b983eb767bad15e67af1174fb0bcf31c.tar.xz
wireguard-openbsd-061da546b983eb767bad15e67af1174fb0bcf31c.zip
Import LLVM 10.0.0 release including clang, lld and lldb.
ok hackroom tested by plenty
Diffstat (limited to 'gnu/llvm/lldb/source/Target/ThreadPlanStepOut.cpp')
-rw-r--r--gnu/llvm/lldb/source/Target/ThreadPlanStepOut.cpp534
1 files changed, 534 insertions, 0 deletions
diff --git a/gnu/llvm/lldb/source/Target/ThreadPlanStepOut.cpp b/gnu/llvm/lldb/source/Target/ThreadPlanStepOut.cpp
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+++ b/gnu/llvm/lldb/source/Target/ThreadPlanStepOut.cpp
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+//===-- ThreadPlanStepOut.cpp -----------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Target/ThreadPlanStepOut.h"
+#include "lldb/Breakpoint/Breakpoint.h"
+#include "lldb/Core/Value.h"
+#include "lldb/Core/ValueObjectConstResult.h"
+#include "lldb/Symbol/Block.h"
+#include "lldb/Symbol/Function.h"
+#include "lldb/Symbol/Symbol.h"
+#include "lldb/Symbol/Type.h"
+#include "lldb/Target/ABI.h"
+#include "lldb/Target/Process.h"
+#include "lldb/Target/RegisterContext.h"
+#include "lldb/Target/StopInfo.h"
+#include "lldb/Target/Target.h"
+#include "lldb/Target/ThreadPlanStepOverRange.h"
+#include "lldb/Target/ThreadPlanStepThrough.h"
+#include "lldb/Utility/Log.h"
+
+#include <memory>
+
+using namespace lldb;
+using namespace lldb_private;
+
+uint32_t ThreadPlanStepOut::s_default_flag_values = 0;
+
+// ThreadPlanStepOut: Step out of the current frame
+ThreadPlanStepOut::ThreadPlanStepOut(
+ Thread &thread, SymbolContext *context, bool first_insn, bool stop_others,
+ Vote stop_vote, Vote run_vote, uint32_t frame_idx,
+ LazyBool step_out_avoids_code_without_debug_info,
+ bool continue_to_next_branch, bool gather_return_value)
+ : ThreadPlan(ThreadPlan::eKindStepOut, "Step out", thread, stop_vote,
+ run_vote),
+ ThreadPlanShouldStopHere(this), m_step_from_insn(LLDB_INVALID_ADDRESS),
+ m_return_bp_id(LLDB_INVALID_BREAK_ID),
+ m_return_addr(LLDB_INVALID_ADDRESS), m_stop_others(stop_others),
+ m_immediate_step_from_function(nullptr),
+ m_calculate_return_value(gather_return_value) {
+ Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+ SetFlagsToDefault();
+ SetupAvoidNoDebug(step_out_avoids_code_without_debug_info);
+
+ m_step_from_insn = m_thread.GetRegisterContext()->GetPC(0);
+
+ uint32_t return_frame_index = frame_idx + 1;
+ StackFrameSP return_frame_sp(
+ m_thread.GetStackFrameAtIndex(return_frame_index));
+ StackFrameSP immediate_return_from_sp(
+ m_thread.GetStackFrameAtIndex(frame_idx));
+
+ if (!return_frame_sp || !immediate_return_from_sp)
+ return; // we can't do anything here. ValidatePlan() will return false.
+
+ // While stepping out, behave as-if artificial frames are not present.
+ while (return_frame_sp->IsArtificial()) {
+ m_stepped_past_frames.push_back(return_frame_sp);
+
+ ++return_frame_index;
+ return_frame_sp = m_thread.GetStackFrameAtIndex(return_frame_index);
+
+ // We never expect to see an artificial frame without a regular ancestor.
+ // If this happens, log the issue and defensively refuse to step out.
+ if (!return_frame_sp) {
+ LLDB_LOG(log, "Can't step out of frame with artificial ancestors");
+ return;
+ }
+ }
+
+ m_step_out_to_id = return_frame_sp->GetStackID();
+ m_immediate_step_from_id = immediate_return_from_sp->GetStackID();
+
+ // If the frame directly below the one we are returning to is inlined, we
+ // have to be a little more careful. It is non-trivial to determine the real
+ // "return code address" for an inlined frame, so we have to work our way to
+ // that frame and then step out.
+ if (immediate_return_from_sp->IsInlined()) {
+ if (frame_idx > 0) {
+ // First queue a plan that gets us to this inlined frame, and when we get
+ // there we'll queue a second plan that walks us out of this frame.
+ m_step_out_to_inline_plan_sp = std::make_shared<ThreadPlanStepOut>(
+ m_thread, nullptr, false, stop_others, eVoteNoOpinion, eVoteNoOpinion,
+ frame_idx - 1, eLazyBoolNo, continue_to_next_branch);
+ static_cast<ThreadPlanStepOut *>(m_step_out_to_inline_plan_sp.get())
+ ->SetShouldStopHereCallbacks(nullptr, nullptr);
+ m_step_out_to_inline_plan_sp->SetPrivate(true);
+ } else {
+ // If we're already at the inlined frame we're stepping through, then
+ // just do that now.
+ QueueInlinedStepPlan(false);
+ }
+ } else {
+ // Find the return address and set a breakpoint there:
+ // FIXME - can we do this more securely if we know first_insn?
+
+ Address return_address(return_frame_sp->GetFrameCodeAddress());
+ if (continue_to_next_branch) {
+ SymbolContext return_address_sc;
+ AddressRange range;
+ Address return_address_decr_pc = return_address;
+ if (return_address_decr_pc.GetOffset() > 0)
+ return_address_decr_pc.Slide(-1);
+
+ return_address_decr_pc.CalculateSymbolContext(
+ &return_address_sc, lldb::eSymbolContextLineEntry);
+ if (return_address_sc.line_entry.IsValid()) {
+ const bool include_inlined_functions = false;
+ range = return_address_sc.line_entry.GetSameLineContiguousAddressRange(
+ include_inlined_functions);
+ if (range.GetByteSize() > 0) {
+ return_address =
+ m_thread.GetProcess()->AdvanceAddressToNextBranchInstruction(
+ return_address, range);
+ }
+ }
+ }
+ m_return_addr =
+ return_address.GetLoadAddress(&m_thread.GetProcess()->GetTarget());
+
+ if (m_return_addr == LLDB_INVALID_ADDRESS)
+ return;
+
+ // Perform some additional validation on the return address.
+ uint32_t permissions = 0;
+ if (!m_thread.GetProcess()->GetLoadAddressPermissions(m_return_addr,
+ permissions)) {
+ m_constructor_errors.Printf("Return address (0x%" PRIx64
+ ") permissions not found.",
+ m_return_addr);
+ LLDB_LOGF(log, "ThreadPlanStepOut(%p): %s", static_cast<void *>(this),
+ m_constructor_errors.GetData());
+ return;
+ } else if (!(permissions & ePermissionsExecutable)) {
+ m_constructor_errors.Printf("Return address (0x%" PRIx64
+ ") did not point to executable memory.",
+ m_return_addr);
+ LLDB_LOGF(log, "ThreadPlanStepOut(%p): %s", static_cast<void *>(this),
+ m_constructor_errors.GetData());
+ return;
+ }
+
+ Breakpoint *return_bp = m_thread.CalculateTarget()
+ ->CreateBreakpoint(m_return_addr, true, false)
+ .get();
+
+ if (return_bp != nullptr) {
+ if (return_bp->IsHardware() && !return_bp->HasResolvedLocations())
+ m_could_not_resolve_hw_bp = true;
+ return_bp->SetThreadID(m_thread.GetID());
+ m_return_bp_id = return_bp->GetID();
+ return_bp->SetBreakpointKind("step-out");
+ }
+
+ if (immediate_return_from_sp) {
+ const SymbolContext &sc =
+ immediate_return_from_sp->GetSymbolContext(eSymbolContextFunction);
+ if (sc.function) {
+ m_immediate_step_from_function = sc.function;
+ }
+ }
+ }
+}
+
+void ThreadPlanStepOut::SetupAvoidNoDebug(
+ LazyBool step_out_avoids_code_without_debug_info) {
+ bool avoid_nodebug = true;
+ switch (step_out_avoids_code_without_debug_info) {
+ case eLazyBoolYes:
+ avoid_nodebug = true;
+ break;
+ case eLazyBoolNo:
+ avoid_nodebug = false;
+ break;
+ case eLazyBoolCalculate:
+ avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug();
+ break;
+ }
+ if (avoid_nodebug)
+ GetFlags().Set(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
+ else
+ GetFlags().Clear(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
+}
+
+void ThreadPlanStepOut::DidPush() {
+ if (m_step_out_to_inline_plan_sp)
+ m_thread.QueueThreadPlan(m_step_out_to_inline_plan_sp, false);
+ else if (m_step_through_inline_plan_sp)
+ m_thread.QueueThreadPlan(m_step_through_inline_plan_sp, false);
+}
+
+ThreadPlanStepOut::~ThreadPlanStepOut() {
+ if (m_return_bp_id != LLDB_INVALID_BREAK_ID)
+ m_thread.CalculateTarget()->RemoveBreakpointByID(m_return_bp_id);
+}
+
+void ThreadPlanStepOut::GetDescription(Stream *s,
+ lldb::DescriptionLevel level) {
+ if (level == lldb::eDescriptionLevelBrief)
+ s->Printf("step out");
+ else {
+ if (m_step_out_to_inline_plan_sp)
+ s->Printf("Stepping out to inlined frame so we can walk through it.");
+ else if (m_step_through_inline_plan_sp)
+ s->Printf("Stepping out by stepping through inlined function.");
+ else {
+ s->Printf("Stepping out from ");
+ Address tmp_address;
+ if (tmp_address.SetLoadAddress(m_step_from_insn, &GetTarget())) {
+ tmp_address.Dump(s, &GetThread(), Address::DumpStyleResolvedDescription,
+ Address::DumpStyleLoadAddress);
+ } else {
+ s->Printf("address 0x%" PRIx64 "", (uint64_t)m_step_from_insn);
+ }
+
+ // FIXME: find some useful way to present the m_return_id, since there may
+ // be multiple copies of the
+ // same function on the stack.
+
+ s->Printf(" returning to frame at ");
+ if (tmp_address.SetLoadAddress(m_return_addr, &GetTarget())) {
+ tmp_address.Dump(s, &GetThread(), Address::DumpStyleResolvedDescription,
+ Address::DumpStyleLoadAddress);
+ } else {
+ s->Printf("address 0x%" PRIx64 "", (uint64_t)m_return_addr);
+ }
+
+ if (level == eDescriptionLevelVerbose)
+ s->Printf(" using breakpoint site %d", m_return_bp_id);
+ }
+ }
+
+ s->Printf("\n");
+ for (StackFrameSP frame_sp : m_stepped_past_frames) {
+ s->Printf("Stepped out past: ");
+ frame_sp->DumpUsingSettingsFormat(s);
+ }
+}
+
+bool ThreadPlanStepOut::ValidatePlan(Stream *error) {
+ if (m_step_out_to_inline_plan_sp)
+ return m_step_out_to_inline_plan_sp->ValidatePlan(error);
+
+ if (m_step_through_inline_plan_sp)
+ return m_step_through_inline_plan_sp->ValidatePlan(error);
+
+ if (m_could_not_resolve_hw_bp) {
+ if (error)
+ error->PutCString(
+ "Could not create hardware breakpoint for thread plan.");
+ return false;
+ }
+
+ if (m_return_bp_id == LLDB_INVALID_BREAK_ID) {
+ if (error) {
+ error->PutCString("Could not create return address breakpoint.");
+ if (m_constructor_errors.GetSize() > 0) {
+ error->PutCString(" ");
+ error->PutCString(m_constructor_errors.GetString());
+ }
+ }
+ return false;
+ }
+
+ return true;
+}
+
+bool ThreadPlanStepOut::DoPlanExplainsStop(Event *event_ptr) {
+ // If the step out plan is done, then we just need to step through the
+ // inlined frame.
+ if (m_step_out_to_inline_plan_sp) {
+ return m_step_out_to_inline_plan_sp->MischiefManaged();
+ } else if (m_step_through_inline_plan_sp) {
+ if (m_step_through_inline_plan_sp->MischiefManaged()) {
+ CalculateReturnValue();
+ SetPlanComplete();
+ return true;
+ } else
+ return false;
+ } else if (m_step_out_further_plan_sp) {
+ return m_step_out_further_plan_sp->MischiefManaged();
+ }
+
+ // We don't explain signals or breakpoints (breakpoints that handle stepping
+ // in or out will be handled by a child plan.
+
+ StopInfoSP stop_info_sp = GetPrivateStopInfo();
+ if (stop_info_sp) {
+ StopReason reason = stop_info_sp->GetStopReason();
+ if (reason == eStopReasonBreakpoint) {
+ // If this is OUR breakpoint, we're fine, otherwise we don't know why
+ // this happened...
+ BreakpointSiteSP site_sp(
+ m_thread.GetProcess()->GetBreakpointSiteList().FindByID(
+ stop_info_sp->GetValue()));
+ if (site_sp && site_sp->IsBreakpointAtThisSite(m_return_bp_id)) {
+ bool done;
+
+ StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
+
+ if (m_step_out_to_id == frame_zero_id)
+ done = true;
+ else if (m_step_out_to_id < frame_zero_id) {
+ // Either we stepped past the breakpoint, or the stack ID calculation
+ // was incorrect and we should probably stop.
+ done = true;
+ } else {
+ done = (m_immediate_step_from_id < frame_zero_id);
+ }
+
+ if (done) {
+ if (InvokeShouldStopHereCallback(eFrameCompareOlder, m_status)) {
+ CalculateReturnValue();
+ SetPlanComplete();
+ }
+ }
+
+ // If there was only one owner, then we're done. But if we also hit
+ // some user breakpoint on our way out, we should mark ourselves as
+ // done, but also not claim to explain the stop, since it is more
+ // important to report the user breakpoint than the step out
+ // completion.
+
+ if (site_sp->GetNumberOfOwners() == 1)
+ return true;
+ }
+ return false;
+ } else if (IsUsuallyUnexplainedStopReason(reason))
+ return false;
+ else
+ return true;
+ }
+ return true;
+}
+
+bool ThreadPlanStepOut::ShouldStop(Event *event_ptr) {
+ if (IsPlanComplete())
+ return true;
+
+ bool done = false;
+ if (m_step_out_to_inline_plan_sp) {
+ if (m_step_out_to_inline_plan_sp->MischiefManaged()) {
+ // Now step through the inlined stack we are in:
+ if (QueueInlinedStepPlan(true)) {
+ // If we can't queue a plan to do this, then just call ourselves done.
+ m_step_out_to_inline_plan_sp.reset();
+ SetPlanComplete(false);
+ return true;
+ } else
+ done = true;
+ } else
+ return m_step_out_to_inline_plan_sp->ShouldStop(event_ptr);
+ } else if (m_step_through_inline_plan_sp) {
+ if (m_step_through_inline_plan_sp->MischiefManaged())
+ done = true;
+ else
+ return m_step_through_inline_plan_sp->ShouldStop(event_ptr);
+ } else if (m_step_out_further_plan_sp) {
+ if (m_step_out_further_plan_sp->MischiefManaged())
+ m_step_out_further_plan_sp.reset();
+ else
+ return m_step_out_further_plan_sp->ShouldStop(event_ptr);
+ }
+
+ if (!done) {
+ StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
+ done = !(frame_zero_id < m_step_out_to_id);
+ }
+
+ // The normal step out computations think we are done, so all we need to do
+ // is consult the ShouldStopHere, and we are done.
+
+ if (done) {
+ if (InvokeShouldStopHereCallback(eFrameCompareOlder, m_status)) {
+ CalculateReturnValue();
+ SetPlanComplete();
+ } else {
+ m_step_out_further_plan_sp =
+ QueueStepOutFromHerePlan(m_flags, eFrameCompareOlder, m_status);
+ done = false;
+ }
+ }
+
+ return done;
+}
+
+bool ThreadPlanStepOut::StopOthers() { return m_stop_others; }
+
+StateType ThreadPlanStepOut::GetPlanRunState() { return eStateRunning; }
+
+bool ThreadPlanStepOut::DoWillResume(StateType resume_state,
+ bool current_plan) {
+ if (m_step_out_to_inline_plan_sp || m_step_through_inline_plan_sp)
+ return true;
+
+ if (m_return_bp_id == LLDB_INVALID_BREAK_ID)
+ return false;
+
+ if (current_plan) {
+ Breakpoint *return_bp =
+ m_thread.CalculateTarget()->GetBreakpointByID(m_return_bp_id).get();
+ if (return_bp != nullptr)
+ return_bp->SetEnabled(true);
+ }
+ return true;
+}
+
+bool ThreadPlanStepOut::WillStop() {
+ if (m_return_bp_id != LLDB_INVALID_BREAK_ID) {
+ Breakpoint *return_bp =
+ m_thread.CalculateTarget()->GetBreakpointByID(m_return_bp_id).get();
+ if (return_bp != nullptr)
+ return_bp->SetEnabled(false);
+ }
+
+ return true;
+}
+
+bool ThreadPlanStepOut::MischiefManaged() {
+ if (IsPlanComplete()) {
+ // Did I reach my breakpoint? If so I'm done.
+ //
+ // I also check the stack depth, since if we've blown past the breakpoint
+ // for some
+ // reason and we're now stopping for some other reason altogether, then
+ // we're done with this step out operation.
+
+ Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+ if (log)
+ LLDB_LOGF(log, "Completed step out plan.");
+ if (m_return_bp_id != LLDB_INVALID_BREAK_ID) {
+ m_thread.CalculateTarget()->RemoveBreakpointByID(m_return_bp_id);
+ m_return_bp_id = LLDB_INVALID_BREAK_ID;
+ }
+
+ ThreadPlan::MischiefManaged();
+ return true;
+ } else {
+ return false;
+ }
+}
+
+bool ThreadPlanStepOut::QueueInlinedStepPlan(bool queue_now) {
+ // Now figure out the range of this inlined block, and set up a "step through
+ // range" plan for that. If we've been provided with a context, then use the
+ // block in that context.
+ StackFrameSP immediate_return_from_sp(m_thread.GetStackFrameAtIndex(0));
+ if (!immediate_return_from_sp)
+ return false;
+
+ Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+ if (log) {
+ StreamString s;
+ immediate_return_from_sp->Dump(&s, true, false);
+ LLDB_LOGF(log, "Queuing inlined frame to step past: %s.", s.GetData());
+ }
+
+ Block *from_block = immediate_return_from_sp->GetFrameBlock();
+ if (from_block) {
+ Block *inlined_block = from_block->GetContainingInlinedBlock();
+ if (inlined_block) {
+ size_t num_ranges = inlined_block->GetNumRanges();
+ AddressRange inline_range;
+ if (inlined_block->GetRangeAtIndex(0, inline_range)) {
+ SymbolContext inlined_sc;
+ inlined_block->CalculateSymbolContext(&inlined_sc);
+ inlined_sc.target_sp = GetTarget().shared_from_this();
+ RunMode run_mode =
+ m_stop_others ? lldb::eOnlyThisThread : lldb::eAllThreads;
+ const LazyBool avoid_no_debug = eLazyBoolNo;
+
+ m_step_through_inline_plan_sp =
+ std::make_shared<ThreadPlanStepOverRange>(
+ m_thread, inline_range, inlined_sc, run_mode, avoid_no_debug);
+ ThreadPlanStepOverRange *step_through_inline_plan_ptr =
+ static_cast<ThreadPlanStepOverRange *>(
+ m_step_through_inline_plan_sp.get());
+ m_step_through_inline_plan_sp->SetPrivate(true);
+
+ step_through_inline_plan_ptr->SetOkayToDiscard(true);
+ StreamString errors;
+ if (!step_through_inline_plan_ptr->ValidatePlan(&errors)) {
+ // FIXME: Log this failure.
+ delete step_through_inline_plan_ptr;
+ return false;
+ }
+
+ for (size_t i = 1; i < num_ranges; i++) {
+ if (inlined_block->GetRangeAtIndex(i, inline_range))
+ step_through_inline_plan_ptr->AddRange(inline_range);
+ }
+
+ if (queue_now)
+ m_thread.QueueThreadPlan(m_step_through_inline_plan_sp, false);
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
+void ThreadPlanStepOut::CalculateReturnValue() {
+ if (m_return_valobj_sp)
+ return;
+
+ if (!m_calculate_return_value)
+ return;
+
+ if (m_immediate_step_from_function != nullptr) {
+ CompilerType return_compiler_type =
+ m_immediate_step_from_function->GetCompilerType()
+ .GetFunctionReturnType();
+ if (return_compiler_type) {
+ lldb::ABISP abi_sp = m_thread.GetProcess()->GetABI();
+ if (abi_sp)
+ m_return_valobj_sp =
+ abi_sp->GetReturnValueObject(m_thread, return_compiler_type);
+ }
+ }
+}
+
+bool ThreadPlanStepOut::IsPlanStale() {
+ // If we are still lower on the stack than the frame we are returning to,
+ // then there's something for us to do. Otherwise, we're stale.
+
+ StackID frame_zero_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
+ return !(frame_zero_id < m_step_out_to_id);
+}