summaryrefslogtreecommitdiffstats
path: root/gnu/llvm/lldb/source/Target/ThreadPlanStepThrough.cpp
diff options
context:
space:
mode:
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/ThreadPlanStepThrough.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/ThreadPlanStepThrough.cpp')
-rw-r--r--gnu/llvm/lldb/source/Target/ThreadPlanStepThrough.cpp266
1 files changed, 266 insertions, 0 deletions
diff --git a/gnu/llvm/lldb/source/Target/ThreadPlanStepThrough.cpp b/gnu/llvm/lldb/source/Target/ThreadPlanStepThrough.cpp
new file mode 100644
index 00000000000..8c7b180fce2
--- /dev/null
+++ b/gnu/llvm/lldb/source/Target/ThreadPlanStepThrough.cpp
@@ -0,0 +1,266 @@
+//===-- ThreadPlanStepThrough.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/ThreadPlanStepThrough.h"
+#include "lldb/Breakpoint/Breakpoint.h"
+#include "lldb/Target/DynamicLoader.h"
+#include "lldb/Target/LanguageRuntime.h"
+#include "lldb/Target/Process.h"
+#include "lldb/Target/RegisterContext.h"
+#include "lldb/Target/Target.h"
+#include "lldb/Utility/Log.h"
+#include "lldb/Utility/Stream.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+// ThreadPlanStepThrough: If the current instruction is a trampoline, step
+// through it If it is the beginning of the prologue of a function, step
+// through that as well.
+// FIXME: At present only handles DYLD trampolines.
+
+ThreadPlanStepThrough::ThreadPlanStepThrough(Thread &thread,
+ StackID &m_stack_id,
+ bool stop_others)
+ : ThreadPlan(ThreadPlan::eKindStepThrough,
+ "Step through trampolines and prologues", thread,
+ eVoteNoOpinion, eVoteNoOpinion),
+ m_start_address(0), m_backstop_bkpt_id(LLDB_INVALID_BREAK_ID),
+ m_backstop_addr(LLDB_INVALID_ADDRESS), m_return_stack_id(m_stack_id),
+ m_stop_others(stop_others) {
+ LookForPlanToStepThroughFromCurrentPC();
+
+ // If we don't get a valid step through plan, don't bother to set up a
+ // backstop.
+ if (m_sub_plan_sp) {
+ m_start_address = GetThread().GetRegisterContext()->GetPC(0);
+
+ // We are going to return back to the concrete frame 1, we might pass by
+ // some inlined code that we're in the middle of by doing this, but it's
+ // easier than trying to figure out where the inlined code might return to.
+
+ StackFrameSP return_frame_sp = m_thread.GetFrameWithStackID(m_stack_id);
+
+ if (return_frame_sp) {
+ m_backstop_addr = return_frame_sp->GetFrameCodeAddress().GetLoadAddress(
+ m_thread.CalculateTarget().get());
+ Breakpoint *return_bp =
+ m_thread.GetProcess()
+ ->GetTarget()
+ .CreateBreakpoint(m_backstop_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_backstop_bkpt_id = return_bp->GetID();
+ return_bp->SetBreakpointKind("step-through-backstop");
+ }
+ Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+ if (log) {
+ LLDB_LOGF(log, "Setting backstop breakpoint %d at address: 0x%" PRIx64,
+ m_backstop_bkpt_id, m_backstop_addr);
+ }
+ }
+ }
+}
+
+ThreadPlanStepThrough::~ThreadPlanStepThrough() { ClearBackstopBreakpoint(); }
+
+void ThreadPlanStepThrough::DidPush() {
+ if (m_sub_plan_sp)
+ PushPlan(m_sub_plan_sp);
+}
+
+void ThreadPlanStepThrough::LookForPlanToStepThroughFromCurrentPC() {
+ DynamicLoader *loader = m_thread.GetProcess()->GetDynamicLoader();
+ if (loader)
+ m_sub_plan_sp =
+ loader->GetStepThroughTrampolinePlan(m_thread, m_stop_others);
+
+ // If the DynamicLoader was unable to provide us with a ThreadPlan, then we
+ // try the LanguageRuntimes.
+ if (!m_sub_plan_sp) {
+ for (LanguageRuntime *runtime :
+ m_thread.GetProcess()->GetLanguageRuntimes()) {
+ m_sub_plan_sp =
+ runtime->GetStepThroughTrampolinePlan(m_thread, m_stop_others);
+
+ if (m_sub_plan_sp)
+ break;
+ }
+ }
+
+ Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+ if (log) {
+ lldb::addr_t current_address = GetThread().GetRegisterContext()->GetPC(0);
+ if (m_sub_plan_sp) {
+ StreamString s;
+ m_sub_plan_sp->GetDescription(&s, lldb::eDescriptionLevelFull);
+ LLDB_LOGF(log, "Found step through plan from 0x%" PRIx64 ": %s",
+ current_address, s.GetData());
+ } else {
+ LLDB_LOGF(log,
+ "Couldn't find step through plan from address 0x%" PRIx64 ".",
+ current_address);
+ }
+ }
+}
+
+void ThreadPlanStepThrough::GetDescription(Stream *s,
+ lldb::DescriptionLevel level) {
+ if (level == lldb::eDescriptionLevelBrief)
+ s->Printf("Step through");
+ else {
+ s->PutCString("Stepping through trampoline code from: ");
+ DumpAddress(s->AsRawOstream(), m_start_address, sizeof(addr_t));
+ if (m_backstop_bkpt_id != LLDB_INVALID_BREAK_ID) {
+ s->Printf(" with backstop breakpoint ID: %d at address: ",
+ m_backstop_bkpt_id);
+ DumpAddress(s->AsRawOstream(), m_backstop_addr, sizeof(addr_t));
+ } else
+ s->PutCString(" unable to set a backstop breakpoint.");
+ }
+}
+
+bool ThreadPlanStepThrough::ValidatePlan(Stream *error) {
+ if (m_could_not_resolve_hw_bp) {
+ if (error)
+ error->PutCString(
+ "Could not create hardware breakpoint for thread plan.");
+ return false;
+ }
+
+ if (m_backstop_bkpt_id == LLDB_INVALID_BREAK_ID) {
+ if (error)
+ error->PutCString("Could not create backstop breakpoint.");
+ return false;
+ }
+
+ if (!m_sub_plan_sp.get()) {
+ if (error)
+ error->PutCString("Does not have a subplan.");
+ return false;
+ }
+
+ return true;
+}
+
+bool ThreadPlanStepThrough::DoPlanExplainsStop(Event *event_ptr) {
+ // If we have a sub-plan, it will have been asked first if we explain the
+ // stop, and we won't get asked. The only time we would be the one directly
+ // asked this question is if we hit our backstop breakpoint.
+
+ return HitOurBackstopBreakpoint();
+}
+
+bool ThreadPlanStepThrough::ShouldStop(Event *event_ptr) {
+ // If we've already marked ourselves done, then we're done...
+ if (IsPlanComplete())
+ return true;
+
+ // First, did we hit the backstop breakpoint?
+ if (HitOurBackstopBreakpoint()) {
+ SetPlanComplete(true);
+ return true;
+ }
+
+ // If we don't have a sub-plan, then we're also done (can't see how we would
+ // ever get here without a plan, but just in case.
+
+ if (!m_sub_plan_sp) {
+ SetPlanComplete();
+ return true;
+ }
+
+ // If the current sub plan is not done, we don't want to stop. Actually, we
+ // probably won't ever get here in this state, since we generally won't get
+ // asked any questions if out current sub-plan is not done...
+ if (!m_sub_plan_sp->IsPlanComplete())
+ return false;
+
+ // If our current sub plan failed, then let's just run to our backstop. If
+ // we can't do that then just stop.
+ if (!m_sub_plan_sp->PlanSucceeded()) {
+ if (m_backstop_bkpt_id != LLDB_INVALID_BREAK_ID) {
+ m_sub_plan_sp.reset();
+ return false;
+ } else {
+ SetPlanComplete(false);
+ return true;
+ }
+ }
+
+ // Next see if there is a specific step through plan at our current pc (these
+ // might chain, for instance stepping through a dylib trampoline to the objc
+ // dispatch function...)
+ LookForPlanToStepThroughFromCurrentPC();
+ if (m_sub_plan_sp) {
+ PushPlan(m_sub_plan_sp);
+ return false;
+ } else {
+ SetPlanComplete();
+ return true;
+ }
+}
+
+bool ThreadPlanStepThrough::StopOthers() { return m_stop_others; }
+
+StateType ThreadPlanStepThrough::GetPlanRunState() { return eStateRunning; }
+
+bool ThreadPlanStepThrough::DoWillResume(StateType resume_state,
+ bool current_plan) {
+ return true;
+}
+
+bool ThreadPlanStepThrough::WillStop() { return true; }
+
+void ThreadPlanStepThrough::ClearBackstopBreakpoint() {
+ if (m_backstop_bkpt_id != LLDB_INVALID_BREAK_ID) {
+ m_thread.GetProcess()->GetTarget().RemoveBreakpointByID(m_backstop_bkpt_id);
+ m_backstop_bkpt_id = LLDB_INVALID_BREAK_ID;
+ m_could_not_resolve_hw_bp = false;
+ }
+}
+
+bool ThreadPlanStepThrough::MischiefManaged() {
+ Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+
+ if (!IsPlanComplete()) {
+ return false;
+ } else {
+ LLDB_LOGF(log, "Completed step through step plan.");
+
+ ClearBackstopBreakpoint();
+ ThreadPlan::MischiefManaged();
+ return true;
+ }
+}
+
+bool ThreadPlanStepThrough::HitOurBackstopBreakpoint() {
+ StopInfoSP stop_info_sp(m_thread.GetStopInfo());
+ if (stop_info_sp && stop_info_sp->GetStopReason() == eStopReasonBreakpoint) {
+ break_id_t stop_value = (break_id_t)stop_info_sp->GetValue();
+ BreakpointSiteSP cur_site_sp =
+ m_thread.GetProcess()->GetBreakpointSiteList().FindByID(stop_value);
+ if (cur_site_sp &&
+ cur_site_sp->IsBreakpointAtThisSite(m_backstop_bkpt_id)) {
+ StackID cur_frame_zero_id =
+ m_thread.GetStackFrameAtIndex(0)->GetStackID();
+
+ if (cur_frame_zero_id == m_return_stack_id) {
+ Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
+ if (log)
+ log->PutCString("ThreadPlanStepThrough hit backstop breakpoint.");
+ return true;
+ }
+ }
+ }
+ return false;
+}