1 files changed, 216 insertions, 0 deletions
diff --git a/contrib/llvm-project/lldb/source/Plugins/DynamicLoader/Windows-DYLD/DynamicLoaderWindowsDYLD.cpp b/contrib/llvm-project/lldb/source/Plugins/DynamicLoader/Windows-DYLD/DynamicLoaderWindowsDYLD.cpp
new file mode 100644
index 000000000000..f044aa786806
--- /dev/null
+++ b/contrib/llvm-project/lldb/source/Plugins/DynamicLoader/Windows-DYLD/DynamicLoaderWindowsDYLD.cpp
@@ -0,0 +1,216 @@
+//===-- DynamicLoaderWindowsDYLD.cpp --------------------------------------===//
+//
+// 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 "DynamicLoaderWindowsDYLD.h"
+
+#include "lldb/Core/Module.h"
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Target/ExecutionContext.h"
+#include "lldb/Target/Platform.h"
+#include "lldb/Target/Process.h"
+#include "lldb/Target/RegisterContext.h"
+#include "lldb/Target/Target.h"
+#include "lldb/Target/ThreadPlanStepInstruction.h"
+#include "lldb/Utility/LLDBLog.h"
+#include "lldb/Utility/Log.h"
+
+#include "llvm/TargetParser/Triple.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+LLDB_PLUGIN_DEFINE(DynamicLoaderWindowsDYLD)
+
+DynamicLoaderWindowsDYLD::DynamicLoaderWindowsDYLD(Process *process)
+    : DynamicLoader(process) {}
+
+DynamicLoaderWindowsDYLD::~DynamicLoaderWindowsDYLD() = default;
+
+void DynamicLoaderWindowsDYLD::Initialize() {
+  PluginManager::RegisterPlugin(GetPluginNameStatic(),
+                                GetPluginDescriptionStatic(), CreateInstance);
+}
+
+void DynamicLoaderWindowsDYLD::Terminate() {}
+
+llvm::StringRef DynamicLoaderWindowsDYLD::GetPluginDescriptionStatic() {
+  return "Dynamic loader plug-in that watches for shared library "
+         "loads/unloads in Windows processes.";
+}
+
+DynamicLoader *DynamicLoaderWindowsDYLD::CreateInstance(Process *process,
+                                                        bool force) {
+  bool should_create = force;
+  if (!should_create) {
+    const llvm::Triple &triple_ref =
+        process->GetTarget().GetArchitecture().GetTriple();
+    if (triple_ref.getOS() == llvm::Triple::Win32)
+      should_create = true;
+  }
+
+  if (should_create)
+    return new DynamicLoaderWindowsDYLD(process);
+
+  return nullptr;
+}
+
+void DynamicLoaderWindowsDYLD::OnLoadModule(lldb::ModuleSP module_sp,
+                                            const ModuleSpec module_spec,
+                                            lldb::addr_t module_addr) {
+
+  // Resolve the module unless we already have one.
+  if (!module_sp) {
+    Status error;
+    module_sp = m_process->GetTarget().GetOrCreateModule(module_spec, 
+                                             true /* notify */, &error);
+    if (error.Fail())
+      return;
+  }
+
+  m_loaded_modules[module_sp] = module_addr;
+  UpdateLoadedSectionsCommon(module_sp, module_addr, false);
+  ModuleList module_list;
+  module_list.Append(module_sp);
+  m_process->GetTarget().ModulesDidLoad(module_list);
+}
+
+void DynamicLoaderWindowsDYLD::OnUnloadModule(lldb::addr_t module_addr) {
+  Address resolved_addr;
+  if (!m_process->GetTarget().ResolveLoadAddress(module_addr, resolved_addr))
+    return;
+
+  ModuleSP module_sp = resolved_addr.GetModule();
+  if (module_sp) {
+    m_loaded_modules.erase(module_sp);
+    UnloadSectionsCommon(module_sp);
+    ModuleList module_list;
+    module_list.Append(module_sp);
+    m_process->GetTarget().ModulesDidUnload(module_list, false);
+  }
+}
+
+lldb::addr_t DynamicLoaderWindowsDYLD::GetLoadAddress(ModuleSP executable) {
+  // First, see if the load address is already cached.
+  auto it = m_loaded_modules.find(executable);
+  if (it != m_loaded_modules.end() && it->second != LLDB_INVALID_ADDRESS)
+    return it->second;
+
+  lldb::addr_t load_addr = LLDB_INVALID_ADDRESS;
+
+  // Second, try to get it through the process plugins.  For a remote process,
+  // the remote platform will be responsible for providing it.
+  FileSpec file_spec(executable->GetPlatformFileSpec());
+  bool is_loaded = false;
+  Status status =
+      m_process->GetFileLoadAddress(file_spec, is_loaded, load_addr);
+  // Servers other than lldb server could respond with a bogus address.
+  if (status.Success() && is_loaded && load_addr != LLDB_INVALID_ADDRESS) {
+    m_loaded_modules[executable] = load_addr;
+    return load_addr;
+  }
+
+  return LLDB_INVALID_ADDRESS;
+}
+
+void DynamicLoaderWindowsDYLD::DidAttach() {
+  Log *log = GetLog(LLDBLog::DynamicLoader);
+  LLDB_LOGF(log, "DynamicLoaderWindowsDYLD::%s()", __FUNCTION__);
+
+  ModuleSP executable = GetTargetExecutable();
+
+  if (!executable.get())
+    return;
+
+  // Try to fetch the load address of the file from the process, since there
+  // could be randomization of the load address.
+  lldb::addr_t load_addr = GetLoadAddress(executable);
+  if (load_addr == LLDB_INVALID_ADDRESS)
+    return;
+
+  // Request the process base address.
+  lldb::addr_t image_base = m_process->GetImageInfoAddress();
+  if (image_base == load_addr)
+    return;
+
+  // Rebase the process's modules if there is a mismatch.
+  UpdateLoadedSections(executable, LLDB_INVALID_ADDRESS, load_addr, false);
+
+  ModuleList module_list;
+  module_list.Append(executable);
+  m_process->GetTarget().ModulesDidLoad(module_list);
+  auto error = m_process->LoadModules();
+  LLDB_LOG_ERROR(log, std::move(error), "failed to load modules: {0}");
+}
+
+void DynamicLoaderWindowsDYLD::DidLaunch() {
+  Log *log = GetLog(LLDBLog::DynamicLoader);
+  LLDB_LOGF(log, "DynamicLoaderWindowsDYLD::%s()", __FUNCTION__);
+
+  ModuleSP executable = GetTargetExecutable();
+  if (!executable.get())
+    return;
+
+  lldb::addr_t load_addr = GetLoadAddress(executable);
+  if (load_addr != LLDB_INVALID_ADDRESS) {
+    // Update the loaded sections so that the breakpoints can be resolved.
+    UpdateLoadedSections(executable, LLDB_INVALID_ADDRESS, load_addr, false);
+
+    ModuleList module_list;
+    module_list.Append(executable);
+    m_process->GetTarget().ModulesDidLoad(module_list);
+    auto error = m_process->LoadModules();
+    LLDB_LOG_ERROR(log, std::move(error), "failed to load modules: {0}");
+  }
+}
+
+Status DynamicLoaderWindowsDYLD::CanLoadImage() { return Status(); }
+
+ThreadPlanSP
+DynamicLoaderWindowsDYLD::GetStepThroughTrampolinePlan(Thread &thread,
+                                                       bool stop) {
+  auto arch = m_process->GetTarget().GetArchitecture();
+  if (arch.GetMachine() != llvm::Triple::x86) {
+    return ThreadPlanSP();
+  }
+
+  uint64_t pc = thread.GetRegisterContext()->GetPC();
+  // Max size of an instruction in x86 is 15 bytes.
+  AddressRange range(pc, 2 * 15);
+
+  DisassemblerSP disassembler_sp = Disassembler::DisassembleRange(
+      arch, nullptr, nullptr, m_process->GetTarget(), range);
+  if (!disassembler_sp) {
+    return ThreadPlanSP();
+  }
+
+  InstructionList *insn_list = &disassembler_sp->GetInstructionList();
+  if (insn_list == nullptr) {
+    return ThreadPlanSP();
+  }
+
+  // First instruction in a x86 Windows trampoline is going to be an indirect
+  // jump through the IAT and the next one will be a nop (usually there for
+  // alignment purposes). e.g.:
+  //     0x70ff4cfc <+956>: jmpl   *0x7100c2a8
+  //     0x70ff4d02 <+962>: nop
+
+  auto first_insn = insn_list->GetInstructionAtIndex(0);
+  auto second_insn = insn_list->GetInstructionAtIndex(1);
+
+  ExecutionContext exe_ctx(m_process->GetTarget());
+  if (first_insn == nullptr || second_insn == nullptr ||
+      strcmp(first_insn->GetMnemonic(&exe_ctx), "jmpl") != 0 ||
+      strcmp(second_insn->GetMnemonic(&exe_ctx), "nop") != 0) {
+    return ThreadPlanSP();
+  }
+
+  assert(first_insn->DoesBranch() && !second_insn->DoesBranch());
+
+  return ThreadPlanSP(new ThreadPlanStepInstruction(
+      thread, false, false, eVoteNoOpinion, eVoteNoOpinion));
+}