--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lldb/source/Expression/UserExpression.cpp	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,400 @@
+//===-- UserExpression.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 "lldb/Host/Config.h"
+
+#include <stdio.h>
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#include <cstdlib>
+#include <map>
+#include <string>
+
+#include "lldb/Core/Module.h"
+#include "lldb/Core/StreamFile.h"
+#include "lldb/Core/ValueObjectConstResult.h"
+#include "lldb/Expression/DiagnosticManager.h"
+#include "lldb/Expression/ExpressionVariable.h"
+#include "lldb/Expression/IRExecutionUnit.h"
+#include "lldb/Expression/IRInterpreter.h"
+#include "lldb/Expression/Materializer.h"
+#include "lldb/Expression/UserExpression.h"
+#include "lldb/Host/HostInfo.h"
+#include "lldb/Symbol/Block.h"
+#include "lldb/Symbol/Function.h"
+#include "lldb/Symbol/ObjectFile.h"
+#include "lldb/Symbol/SymbolVendor.h"
+#include "lldb/Symbol/Type.h"
+#include "lldb/Symbol/TypeSystem.h"
+#include "lldb/Symbol/VariableList.h"
+#include "lldb/Target/ExecutionContext.h"
+#include "lldb/Target/Process.h"
+#include "lldb/Target/StackFrame.h"
+#include "lldb/Target/Target.h"
+#include "lldb/Target/ThreadPlan.h"
+#include "lldb/Target/ThreadPlanCallUserExpression.h"
+#include "lldb/Utility/ConstString.h"
+#include "lldb/Utility/Log.h"
+#include "lldb/Utility/StreamString.h"
+
+using namespace lldb_private;
+
+char UserExpression::ID;
+
+UserExpression::UserExpression(ExecutionContextScope &exe_scope,
+                               llvm::StringRef expr, llvm::StringRef prefix,
+                               lldb::LanguageType language,
+                               ResultType desired_type,
+                               const EvaluateExpressionOptions &options)
+    : Expression(exe_scope), m_expr_text(std::string(expr)),
+      m_expr_prefix(std::string(prefix)), m_language(language),
+      m_desired_type(desired_type), m_options(options) {}
+
+UserExpression::~UserExpression() {}
+
+void UserExpression::InstallContext(ExecutionContext &exe_ctx) {
+  m_jit_process_wp = exe_ctx.GetProcessSP();
+
+  lldb::StackFrameSP frame_sp = exe_ctx.GetFrameSP();
+
+  if (frame_sp)
+    m_address = frame_sp->GetFrameCodeAddress();
+}
+
+bool UserExpression::LockAndCheckContext(ExecutionContext &exe_ctx,
+                                         lldb::TargetSP &target_sp,
+                                         lldb::ProcessSP &process_sp,
+                                         lldb::StackFrameSP &frame_sp) {
+  lldb::ProcessSP expected_process_sp = m_jit_process_wp.lock();
+  process_sp = exe_ctx.GetProcessSP();
+
+  if (process_sp != expected_process_sp)
+    return false;
+
+  process_sp = exe_ctx.GetProcessSP();
+  target_sp = exe_ctx.GetTargetSP();
+  frame_sp = exe_ctx.GetFrameSP();
+
+  if (m_address.IsValid()) {
+    if (!frame_sp)
+      return false;
+    return (Address::CompareLoadAddress(m_address,
+                                        frame_sp->GetFrameCodeAddress(),
+                                        target_sp.get()) == 0);
+  }
+
+  return true;
+}
+
+bool UserExpression::MatchesContext(ExecutionContext &exe_ctx) {
+  lldb::TargetSP target_sp;
+  lldb::ProcessSP process_sp;
+  lldb::StackFrameSP frame_sp;
+
+  return LockAndCheckContext(exe_ctx, target_sp, process_sp, frame_sp);
+}
+
+lldb::addr_t UserExpression::GetObjectPointer(lldb::StackFrameSP frame_sp,
+                                              ConstString &object_name,
+                                              Status &err) {
+  err.Clear();
+
+  if (!frame_sp) {
+    err.SetErrorStringWithFormat(
+        "Couldn't load '%s' because the context is incomplete",
+        object_name.AsCString());
+    return LLDB_INVALID_ADDRESS;
+  }
+
+  lldb::VariableSP var_sp;
+  lldb::ValueObjectSP valobj_sp;
+
+  valobj_sp = frame_sp->GetValueForVariableExpressionPath(
+      object_name.GetStringRef(), lldb::eNoDynamicValues,
+      StackFrame::eExpressionPathOptionCheckPtrVsMember |
+          StackFrame::eExpressionPathOptionsNoFragileObjcIvar |
+          StackFrame::eExpressionPathOptionsNoSyntheticChildren |
+          StackFrame::eExpressionPathOptionsNoSyntheticArrayRange,
+      var_sp, err);
+
+  if (!err.Success() || !valobj_sp.get())
+    return LLDB_INVALID_ADDRESS;
+
+  lldb::addr_t ret = valobj_sp->GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
+
+  if (ret == LLDB_INVALID_ADDRESS) {
+    err.SetErrorStringWithFormat(
+        "Couldn't load '%s' because its value couldn't be evaluated",
+        object_name.AsCString());
+    return LLDB_INVALID_ADDRESS;
+  }
+
+  return ret;
+}
+
+lldb::ExpressionResults
+UserExpression::Evaluate(ExecutionContext &exe_ctx,
+                         const EvaluateExpressionOptions &options,
+                         llvm::StringRef expr, llvm::StringRef prefix,
+                         lldb::ValueObjectSP &result_valobj_sp, Status &error,
+                         std::string *fixed_expression, ValueObject *ctx_obj) {
+  Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
+                                                  LIBLLDB_LOG_STEP));
+
+  if (ctx_obj) {
+    static unsigned const ctx_type_mask =
+        lldb::TypeFlags::eTypeIsClass | lldb::TypeFlags::eTypeIsStructUnion;
+    if (!(ctx_obj->GetTypeInfo() & ctx_type_mask)) {
+      LLDB_LOG(log, "== [UserExpression::Evaluate] Passed a context object of "
+                    "an invalid type, can't run expressions.");
+      error.SetErrorString("a context object of an invalid type passed");
+      return lldb::eExpressionSetupError;
+    }
+  }
+
+  lldb_private::ExecutionPolicy execution_policy = options.GetExecutionPolicy();
+  lldb::LanguageType language = options.GetLanguage();
+  const ResultType desired_type = options.DoesCoerceToId()
+                                      ? UserExpression::eResultTypeId
+                                      : UserExpression::eResultTypeAny;
+  lldb::ExpressionResults execution_results = lldb::eExpressionSetupError;
+
+  Target *target = exe_ctx.GetTargetPtr();
+  if (!target) {
+    LLDB_LOGF(log, "== [UserExpression::Evaluate] Passed a NULL target, can't "
+                   "run expressions.");
+    error.SetErrorString("expression passed a null target");
+    return lldb::eExpressionSetupError;
+  }
+
+  Process *process = exe_ctx.GetProcessPtr();
+
+  if (process == nullptr || process->GetState() != lldb::eStateStopped) {
+    if (execution_policy == eExecutionPolicyAlways) {
+      LLDB_LOGF(log,
+                "== [UserExpression::Evaluate] Expression may not run, but "
+                "is not constant ==");
+
+      error.SetErrorString("expression needed to run but couldn't");
+
+      return execution_results;
+    }
+  }
+
+  if (process == nullptr || !process->CanJIT())
+    execution_policy = eExecutionPolicyNever;
+
+  // We need to set the expression execution thread here, turns out parse can
+  // call functions in the process of looking up symbols, which will escape the
+  // context set by exe_ctx passed to Execute.
+  lldb::ThreadSP thread_sp = exe_ctx.GetThreadSP();
+  ThreadList::ExpressionExecutionThreadPusher execution_thread_pusher(
+      thread_sp);
+
+  llvm::StringRef full_prefix;
+  llvm::StringRef option_prefix(options.GetPrefix());
+  std::string full_prefix_storage;
+  if (!prefix.empty() && !option_prefix.empty()) {
+    full_prefix_storage = std::string(prefix);
+    full_prefix_storage.append(std::string(option_prefix));
+    full_prefix = full_prefix_storage;
+  } else if (!prefix.empty())
+    full_prefix = prefix;
+  else
+    full_prefix = option_prefix;
+
+  // If the language was not specified in the expression command, set it to the
+  // language in the target's properties if specified, else default to the
+  // langage for the frame.
+  if (language == lldb::eLanguageTypeUnknown) {
+    if (target->GetLanguage() != lldb::eLanguageTypeUnknown)
+      language = target->GetLanguage();
+    else if (StackFrame *frame = exe_ctx.GetFramePtr())
+      language = frame->GetLanguage();
+  }
+
+  lldb::UserExpressionSP user_expression_sp(
+      target->GetUserExpressionForLanguage(expr, full_prefix, language,
+                                           desired_type, options, ctx_obj,
+                                           error));
+  if (error.Fail()) {
+    if (log)
+      LLDB_LOGF(log, "== [UserExpression::Evaluate] Getting expression: %s ==",
+                error.AsCString());
+    return lldb::eExpressionSetupError;
+  }
+
+  if (log)
+    LLDB_LOGF(log, "== [UserExpression::Evaluate] Parsing expression %s ==",
+              expr.str().c_str());
+
+  const bool keep_expression_in_memory = true;
+  const bool generate_debug_info = options.GetGenerateDebugInfo();
+
+  if (options.InvokeCancelCallback(lldb::eExpressionEvaluationParse)) {
+    error.SetErrorString("expression interrupted by callback before parse");
+    result_valobj_sp = ValueObjectConstResult::Create(
+        exe_ctx.GetBestExecutionContextScope(), error);
+    return lldb::eExpressionInterrupted;
+  }
+
+  DiagnosticManager diagnostic_manager;
+
+  bool parse_success =
+      user_expression_sp->Parse(diagnostic_manager, exe_ctx, execution_policy,
+                                keep_expression_in_memory, generate_debug_info);
+
+  // Calculate the fixed expression always, since we need it for errors.
+  std::string tmp_fixed_expression;
+  if (fixed_expression == nullptr)
+    fixed_expression = &tmp_fixed_expression;
+
+  const char *fixed_text = user_expression_sp->GetFixedText();
+  if (fixed_text != nullptr)
+    fixed_expression->append(fixed_text);
+
+  // If there is a fixed expression, try to parse it:
+  if (!parse_success) {
+    execution_results = lldb::eExpressionParseError;
+    if (fixed_expression && !fixed_expression->empty() &&
+        options.GetAutoApplyFixIts()) {
+      lldb::UserExpressionSP fixed_expression_sp(
+          target->GetUserExpressionForLanguage(fixed_expression->c_str(),
+                                               full_prefix, language,
+                                               desired_type, options, ctx_obj,
+                                               error));
+      DiagnosticManager fixed_diagnostic_manager;
+      parse_success = fixed_expression_sp->Parse(
+          fixed_diagnostic_manager, exe_ctx, execution_policy,
+          keep_expression_in_memory, generate_debug_info);
+      if (parse_success) {
+        diagnostic_manager.Clear();
+        user_expression_sp = fixed_expression_sp;
+      } else {
+        // If the fixed expression failed to parse, don't tell the user about,
+        // that won't help.
+        fixed_expression->clear();
+      }
+    }
+
+    if (!parse_success) {
+      if (!fixed_expression->empty() && target->GetEnableNotifyAboutFixIts()) {
+        error.SetExpressionErrorWithFormat(
+            execution_results,
+            "expression failed to parse, fixed expression suggested:\n  %s",
+            fixed_expression->c_str());
+      } else {
+        if (!diagnostic_manager.Diagnostics().size())
+          error.SetExpressionError(execution_results,
+                                   "expression failed to parse, unknown error");
+        else
+          error.SetExpressionError(execution_results,
+                                   diagnostic_manager.GetString().c_str());
+      }
+    }
+  }
+
+  if (parse_success) {
+    lldb::ExpressionVariableSP expr_result;
+
+    if (execution_policy == eExecutionPolicyNever &&
+        !user_expression_sp->CanInterpret()) {
+      if (log)
+        LLDB_LOGF(log,
+                  "== [UserExpression::Evaluate] Expression may not run, but "
+                  "is not constant ==");
+
+      if (!diagnostic_manager.Diagnostics().size())
+        error.SetExpressionError(lldb::eExpressionSetupError,
+                                 "expression needed to run but couldn't");
+    } else if (execution_policy == eExecutionPolicyTopLevel) {
+      error.SetError(UserExpression::kNoResult, lldb::eErrorTypeGeneric);
+      return lldb::eExpressionCompleted;
+    } else {
+      if (options.InvokeCancelCallback(lldb::eExpressionEvaluationExecution)) {
+        error.SetExpressionError(
+            lldb::eExpressionInterrupted,
+            "expression interrupted by callback before execution");
+        result_valobj_sp = ValueObjectConstResult::Create(
+            exe_ctx.GetBestExecutionContextScope(), error);
+        return lldb::eExpressionInterrupted;
+      }
+
+      diagnostic_manager.Clear();
+
+      if (log)
+        LLDB_LOGF(log, "== [UserExpression::Evaluate] Executing expression ==");
+
+      execution_results =
+          user_expression_sp->Execute(diagnostic_manager, exe_ctx, options,
+                                      user_expression_sp, expr_result);
+
+      if (execution_results != lldb::eExpressionCompleted) {
+        if (log)
+          LLDB_LOGF(log, "== [UserExpression::Evaluate] Execution completed "
+                         "abnormally ==");
+
+        if (!diagnostic_manager.Diagnostics().size())
+          error.SetExpressionError(
+              execution_results, "expression failed to execute, unknown error");
+        else
+          error.SetExpressionError(execution_results,
+                                   diagnostic_manager.GetString().c_str());
+      } else {
+        if (expr_result) {
+          result_valobj_sp = expr_result->GetValueObject();
+
+          if (log)
+            LLDB_LOGF(log,
+                      "== [UserExpression::Evaluate] Execution completed "
+                      "normally with result %s ==",
+                      result_valobj_sp->GetValueAsCString());
+        } else {
+          if (log)
+            LLDB_LOGF(log, "== [UserExpression::Evaluate] Execution completed "
+                           "normally with no result ==");
+
+          error.SetError(UserExpression::kNoResult, lldb::eErrorTypeGeneric);
+        }
+      }
+    }
+  }
+
+  if (options.InvokeCancelCallback(lldb::eExpressionEvaluationComplete)) {
+    error.SetExpressionError(
+        lldb::eExpressionInterrupted,
+        "expression interrupted by callback after complete");
+    return lldb::eExpressionInterrupted;
+  }
+
+  if (result_valobj_sp.get() == nullptr) {
+    result_valobj_sp = ValueObjectConstResult::Create(
+        exe_ctx.GetBestExecutionContextScope(), error);
+  }
+
+  return execution_results;
+}
+
+lldb::ExpressionResults
+UserExpression::Execute(DiagnosticManager &diagnostic_manager,
+                        ExecutionContext &exe_ctx,
+                        const EvaluateExpressionOptions &options,
+                        lldb::UserExpressionSP &shared_ptr_to_me,
+                        lldb::ExpressionVariableSP &result_var) {
+  lldb::ExpressionResults expr_result = DoExecute(
+      diagnostic_manager, exe_ctx, options, shared_ptr_to_me, result_var);
+  Target *target = exe_ctx.GetTargetPtr();
+  if (options.GetResultIsInternal() && result_var && target) {
+    if (auto *persistent_state =
+            target->GetPersistentExpressionStateForLanguage(m_language))
+      persistent_state->RemovePersistentVariable(result_var);
+  }
+  return expr_result;
+}