// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/globals.h"
#if !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
#include "vm/source_report.h"

#include "vm/compiler/jit/compiler.h"
#include "vm/isolate.h"
#include "vm/kernel_loader.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/profiler.h"
#include "vm/profiler_service.h"

namespace dart {

const char* SourceReport::kCallSitesStr = "_CallSites";
const char* SourceReport::kCoverageStr = "Coverage";
const char* SourceReport::kPossibleBreakpointsStr = "PossibleBreakpoints";
const char* SourceReport::kProfileStr = "_Profile";

SourceReport::SourceReport(intptr_t report_set, CompileMode compile_mode)
    : report_set_(report_set),
      compile_mode_(compile_mode),
      thread_(NULL),
      script_(NULL),
      start_pos_(TokenPosition::kNoSource),
      end_pos_(TokenPosition::kNoSource),
      profile_(Isolate::Current()),
      next_script_index_(0) {}

SourceReport::~SourceReport() {
  ClearScriptTable();
}

void SourceReport::ClearScriptTable() {
  for (intptr_t i = 0; i < script_table_entries_.length(); i++) {
    delete script_table_entries_[i];
    script_table_entries_[i] = NULL;
  }
  script_table_entries_.Clear();
  script_table_.Clear();
  next_script_index_ = 0;
}

void SourceReport::Init(Thread* thread,
                        const Script* script,
                        TokenPosition start_pos,
                        TokenPosition end_pos) {
  thread_ = thread;
  script_ = script;
  start_pos_ = start_pos;
  end_pos_ = end_pos;
  ClearScriptTable();
  if (IsReportRequested(kProfile)) {
    // Build the profile.
    SampleFilter samplesForIsolate(thread_->isolate()->main_port(),
                                   Thread::kMutatorTask, -1, -1);
    profile_.Build(thread, &samplesForIsolate, Profiler::sample_buffer(),
                   Profile::kNoTags);
  }
}

bool SourceReport::IsReportRequested(ReportKind report_kind) {
  return (report_set_ & report_kind) != 0;
}

bool SourceReport::ShouldSkipFunction(const Function& func) {
  // TODO(32315): Verify that the check is still needed after the issue is
  // resolved.
  if (!func.token_pos().IsReal() || !func.end_token_pos().IsReal()) {
    // At least one of the token positions is not known.
    return true;
  }

  if (script_ != NULL && !script_->IsNull()) {
    if (func.script() != script_->raw()) {
      // The function is from the wrong script.
      return true;
    }
    if (((start_pos_ > TokenPosition::kMinSource) &&
         (func.end_token_pos() < start_pos_)) ||
        ((end_pos_ > TokenPosition::kMinSource) &&
         (func.token_pos() > end_pos_))) {
      // The function does not intersect with the requested token range.
      return true;
    }
  }

  // These don't have unoptimized code and are only used for synthetic stubs.
  if (func.ForceOptimize()) return true;

  switch (func.kind()) {
    case RawFunction::kRegularFunction:
    case RawFunction::kClosureFunction:
    case RawFunction::kImplicitClosureFunction:
    case RawFunction::kImplicitStaticGetter:
    case RawFunction::kFieldInitializer:
    case RawFunction::kGetterFunction:
    case RawFunction::kSetterFunction:
    case RawFunction::kConstructor:
      break;
    default:
      return true;
  }
  if (func.is_abstract() || func.IsImplicitConstructor() ||
      func.IsRedirectingFactory() || func.is_no_such_method_forwarder()) {
    return true;
  }
  // Note that context_scope() remains null for closures declared in bytecode,
  // because the same information is retrieved from the parent's local variable
  // descriptors.
  // See IsLocalFunction() case in BytecodeReader::ComputeLocalVarDescriptors.
  if (!func.is_declared_in_bytecode() && func.IsNonImplicitClosureFunction() &&
      (func.context_scope() == ContextScope::null())) {
    // TODO(iposva): This can arise if we attempt to compile an inner function
    // before we have compiled its enclosing function or if the enclosing
    // function failed to compile.
    return true;
  }
  return false;
}

bool SourceReport::ShouldSkipField(const Field& field) {
  if (!field.token_pos().IsReal() || !field.end_token_pos().IsReal()) {
    // At least one of the token positions is not known.
    return true;
  }

  if (script_ != NULL && !script_->IsNull()) {
    if (field.Script() != script_->raw()) {
      // The field is from the wrong script.
      return true;
    }
    if (((start_pos_ > TokenPosition::kMinSource) &&
         (field.end_token_pos() < start_pos_)) ||
        ((end_pos_ > TokenPosition::kMinSource) &&
         (field.token_pos() > end_pos_))) {
      // The field does not intersect with the requested token range.
      return true;
    }
  }
  return false;
}

intptr_t SourceReport::GetScriptIndex(const Script& script) {
  ScriptTableEntry wrapper;
  const String& url = String::Handle(zone(), script.url());
  wrapper.key = &url;
  wrapper.script = &Script::Handle(zone(), script.raw());
  ScriptTableEntry* pair = script_table_.LookupValue(&wrapper);
  if (pair != NULL) {
    return pair->index;
  }
  ScriptTableEntry* tmp = new ScriptTableEntry();
  tmp->key = &url;
  tmp->index = next_script_index_++;
  tmp->script = wrapper.script;
  script_table_entries_.Add(tmp);
  script_table_.Insert(tmp);
  ASSERT(script_table_entries_.length() == next_script_index_);
#if defined(DEBUG)
  VerifyScriptTable();
#endif
  return tmp->index;
}

#if defined(DEBUG)
void SourceReport::VerifyScriptTable() {
  for (intptr_t i = 0; i < script_table_entries_.length(); i++) {
    const String* url = script_table_entries_[i]->key;
    const Script* script = script_table_entries_[i]->script;
    intptr_t index = script_table_entries_[i]->index;
    ASSERT(i == index);
    const String& url2 = String::Handle(zone(), script->url());
    ASSERT(url2.Equals(*url));
    ScriptTableEntry wrapper;
    wrapper.key = &url2;
    wrapper.script = &Script::Handle(zone(), script->raw());
    ScriptTableEntry* pair = script_table_.LookupValue(&wrapper);
    ASSERT(i == pair->index);
  }
}
#endif

bool SourceReport::ScriptIsLoadedByLibrary(const Script& script,
                                           const Library& lib) {
  const Array& scripts = Array::Handle(zone(), lib.LoadedScripts());
  for (intptr_t j = 0; j < scripts.Length(); j++) {
    if (scripts.At(j) == script.raw()) {
      return true;
    }
  }
  return false;
}

void SourceReport::PrintCallSitesData(JSONObject* jsobj,
                                      const Function& function,
                                      const Code& code) {
  if (code.IsNull()) {
    // TODO(regis): implement for bytecode.
    return;
  }
  const TokenPosition begin_pos = function.token_pos();
  const TokenPosition end_pos = function.end_token_pos();

  ZoneGrowableArray<const ICData*>* ic_data_array =
      new (zone()) ZoneGrowableArray<const ICData*>();
  function.RestoreICDataMap(ic_data_array, false /* clone ic-data */);
  const PcDescriptors& descriptors =
      PcDescriptors::Handle(zone(), code.pc_descriptors());

  JSONArray sites(jsobj, "callSites");

  PcDescriptors::Iterator iter(
      descriptors,
      RawPcDescriptors::kIcCall | RawPcDescriptors::kUnoptStaticCall);
  while (iter.MoveNext()) {
    HANDLESCOPE(thread());
// TODO(zra): Remove this bailout once DBC has reliable ICData.
#if defined(TARGET_ARCH_DBC)
    if (iter.DeoptId() >= ic_data_array->length()) {
      continue;
    }
#else
    ASSERT(iter.DeoptId() < ic_data_array->length());
#endif
    const ICData* ic_data = (*ic_data_array)[iter.DeoptId()];
    if (ic_data != NULL) {
      const TokenPosition token_pos = iter.TokenPos();
      if ((token_pos < begin_pos) || (token_pos > end_pos)) {
        // Does not correspond to a valid source position.
        continue;
      }
      ic_data->PrintToJSONArray(sites, token_pos);
    }
  }
}

void SourceReport::PrintCoverageData(JSONObject* jsobj,
                                     const Function& function,
                                     const Code& code) {
  if (code.IsNull()) {
    // TODO(regis): implement for bytecode.
    return;
  }
  const TokenPosition begin_pos = function.token_pos();
  const TokenPosition end_pos = function.end_token_pos();

  ZoneGrowableArray<const ICData*>* ic_data_array =
      new (zone()) ZoneGrowableArray<const ICData*>();
  function.RestoreICDataMap(ic_data_array, false /* clone ic-data */);
  const PcDescriptors& descriptors =
      PcDescriptors::Handle(zone(), code.pc_descriptors());

  const int kCoverageNone = 0;
  const int kCoverageMiss = 1;
  const int kCoverageHit = 2;

  intptr_t func_length = (end_pos.Pos() - begin_pos.Pos()) + 1;
  GrowableArray<char> coverage(func_length);
  coverage.SetLength(func_length);
  for (int i = 0; i < func_length; i++) {
    coverage[i] = kCoverageNone;
  }

  if (function.WasExecuted()) {
    coverage[0] = kCoverageHit;
  } else {
    coverage[0] = kCoverageMiss;
  }

  PcDescriptors::Iterator iter(
      descriptors,
      RawPcDescriptors::kIcCall | RawPcDescriptors::kUnoptStaticCall);
  while (iter.MoveNext()) {
    HANDLESCOPE(thread());
// TODO(zra): Remove this bailout once DBC has reliable ICData.
#if defined(TARGET_ARCH_DBC)
    if (iter.DeoptId() >= ic_data_array->length()) {
      continue;
    }
#else
    ASSERT(iter.DeoptId() < ic_data_array->length());
#endif
    const ICData* ic_data = (*ic_data_array)[iter.DeoptId()];
    if (ic_data != NULL) {
      const TokenPosition token_pos = iter.TokenPos();
      if ((token_pos < begin_pos) || (token_pos > end_pos)) {
        // Does not correspond to a valid source position.
        continue;
      }
      intptr_t count = ic_data->AggregateCount();
      intptr_t token_offset = token_pos.Pos() - begin_pos.Pos();
      if (count > 0) {
        coverage[token_offset] = kCoverageHit;
      } else {
        if (coverage[token_offset] == kCoverageNone) {
          coverage[token_offset] = kCoverageMiss;
        }
      }
    }
  }

  JSONObject cov(jsobj, "coverage");
  {
    JSONArray hits(&cov, "hits");
    for (int i = 0; i < func_length; i++) {
      if (coverage[i] == kCoverageHit) {
        // Add the token position of the hit.
        hits.AddValue(begin_pos.Pos() + i);
      }
    }
  }
  {
    JSONArray misses(&cov, "misses");
    for (int i = 0; i < func_length; i++) {
      if (coverage[i] == kCoverageMiss) {
        // Add the token position of the miss.
        misses.AddValue(begin_pos.Pos() + i);
      }
    }
  }
}

void SourceReport::PrintPossibleBreakpointsData(JSONObject* jsobj,
                                                const Function& func,
                                                const Code& code) {
  const TokenPosition begin_pos = func.token_pos();
  const TokenPosition end_pos = func.end_token_pos();
  intptr_t func_length = (end_pos.Pos() - begin_pos.Pos()) + 1;
  GrowableArray<char> possible(func_length);
  possible.SetLength(func_length);
  for (int i = 0; i < func_length; i++) {
    possible[i] = false;
  }

  if (code.IsNull()) {
    const Bytecode& bytecode = Bytecode::Handle(func.bytecode());
    ASSERT(!bytecode.IsNull());
    kernel::BytecodeSourcePositionsIterator iter(zone(), bytecode);
    intptr_t token_offset = -1;
    uword pc_offset = kUwordMax;
    // Ignore all possible breakpoint positions until the first DebugCheck
    // opcode of the function.
    const uword debug_check_pc = bytecode.GetFirstDebugCheckOpcodePc();
    if (debug_check_pc != 0) {
      const uword debug_check_pc_offset =
          debug_check_pc - bytecode.PayloadStart();
      while (iter.MoveNext()) {
        if (pc_offset != kUwordMax) {
          // Check that there is at least one 'debug checked' opcode in the last
          // source position range.
          if (bytecode.GetDebugCheckedOpcodeReturnAddress(
                  pc_offset, iter.PcOffset()) != 0) {
            possible[token_offset] = true;
          }
          pc_offset = kUwordMax;
        }
        const TokenPosition token_pos = iter.TokenPos();
        if ((token_pos < begin_pos) || (token_pos > end_pos)) {
          // Does not correspond to a valid source position.
          continue;
        }
        if (iter.PcOffset() < debug_check_pc_offset) {
          // No breakpoints in prologue.
          continue;
        }
        pc_offset = iter.PcOffset();
        token_offset = token_pos.Pos() - begin_pos.Pos();
      }
    }
    if (pc_offset != kUwordMax && bytecode.GetDebugCheckedOpcodeReturnAddress(
                                      pc_offset, bytecode.Size()) != 0) {
      possible[token_offset] = true;
    }
  } else {
    const uint8_t kSafepointKind =
        (RawPcDescriptors::kIcCall | RawPcDescriptors::kUnoptStaticCall |
         RawPcDescriptors::kRuntimeCall);

    const PcDescriptors& descriptors =
        PcDescriptors::Handle(zone(), code.pc_descriptors());

    PcDescriptors::Iterator iter(descriptors, kSafepointKind);
    while (iter.MoveNext()) {
      const TokenPosition token_pos = iter.TokenPos();
      if ((token_pos < begin_pos) || (token_pos > end_pos)) {
        // Does not correspond to a valid source position.
        continue;
      }
      intptr_t token_offset = token_pos.Pos() - begin_pos.Pos();
      possible[token_offset] = true;
    }
  }

  JSONArray bpts(jsobj, "possibleBreakpoints");
  for (int i = 0; i < func_length; i++) {
    if (possible[i]) {
      // Add the token position.
      bpts.AddValue(begin_pos.Pos() + i);
    }
  }
}

void SourceReport::PrintProfileData(JSONObject* jsobj,
                                    ProfileFunction* profile_function) {
  ASSERT(profile_function != NULL);
  ASSERT(profile_function->NumSourcePositions() > 0);

  {
    JSONObject profile(jsobj, "profile");

    {
      JSONObject profileData(&profile, "metadata");
      profileData.AddProperty("sampleCount", profile_.sample_count());
    }

    // Positions.
    {
      JSONArray positions(&profile, "positions");
      for (intptr_t i = 0; i < profile_function->NumSourcePositions(); i++) {
        const ProfileFunctionSourcePosition& position =
            profile_function->GetSourcePosition(i);
        if (position.token_pos().IsSourcePosition()) {
          // Add as an integer.
          positions.AddValue(position.token_pos().Pos());
        } else {
          // Add as a string.
          positions.AddValue(position.token_pos().ToCString());
        }
      }
    }

    // Exclusive ticks.
    {
      JSONArray exclusiveTicks(&profile, "exclusiveTicks");
      for (intptr_t i = 0; i < profile_function->NumSourcePositions(); i++) {
        const ProfileFunctionSourcePosition& position =
            profile_function->GetSourcePosition(i);
        exclusiveTicks.AddValue(position.exclusive_ticks());
      }
    }
    // Inclusive ticks.
    {
      JSONArray inclusiveTicks(&profile, "inclusiveTicks");
      for (intptr_t i = 0; i < profile_function->NumSourcePositions(); i++) {
        const ProfileFunctionSourcePosition& position =
            profile_function->GetSourcePosition(i);
        inclusiveTicks.AddValue(position.inclusive_ticks());
      }
    }
  }
}

void SourceReport::PrintScriptTable(JSONArray* scripts) {
  for (intptr_t i = 0; i < script_table_entries_.length(); i++) {
    const Script* script = script_table_entries_[i]->script;
    scripts->AddValue(*script);
  }
}

void SourceReport::VisitFunction(JSONArray* jsarr, const Function& func) {
  if (ShouldSkipFunction(func)) {
    return;
  }

  const Script& script = Script::Handle(zone(), func.script());
  const TokenPosition begin_pos = func.token_pos();
  const TokenPosition end_pos = func.end_token_pos();

  Code& code = Code::Handle(zone(), func.unoptimized_code());
  Bytecode& bytecode = Bytecode::Handle(zone());
#if !defined(DART_PRECOMPILED_RUNTIME)
  if (FLAG_enable_interpreter && !func.HasCode() && func.HasBytecode()) {
    // When the bytecode of a function is loaded, the function code is not null,
    // but pointing to the stub to interpret the bytecode. The various Print
    // functions below take code as an argument and know to process the bytecode
    // if code is null.
    code = Code::null();  // Ignore installed stub to interpret bytecode.
    bytecode = func.bytecode();
  }
#endif  // !defined(DART_PRECOMPILED_RUNTIME)
  if (code.IsNull() && bytecode.IsNull()) {
    if (func.HasCode() || (compile_mode_ == kForceCompile)) {
      const Error& err =
          Error::Handle(Compiler::EnsureUnoptimizedCode(thread(), func));
      if (!err.IsNull()) {
        // Emit an uncompiled range for this function with error information.
        JSONObject range(jsarr);
        range.AddProperty("scriptIndex", GetScriptIndex(script));
        range.AddProperty("startPos", begin_pos);
        range.AddProperty("endPos", end_pos);
        range.AddProperty("compiled", false);
        range.AddProperty("error", err);
        return;
      }
      code = func.unoptimized_code();
#if !defined(DART_PRECOMPILED_RUNTIME)
      if (FLAG_enable_interpreter && !func.HasCode() && func.HasBytecode()) {
        code = Code::null();  // Ignore installed stub to interpret bytecode.
        bytecode = func.bytecode();
      }
#endif  // !defined(DART_PRECOMPILED_RUNTIME)
    } else {
      // This function has not been compiled yet.
      JSONObject range(jsarr);
      range.AddProperty("scriptIndex", GetScriptIndex(script));
      range.AddProperty("startPos", begin_pos);
      range.AddProperty("endPos", end_pos);
      range.AddProperty("compiled", false);
      return;
    }
  }
  ASSERT(!code.IsNull() || !bytecode.IsNull());

  // We skip compiled async functions.  Once an async function has
  // been compiled, there is another function with the same range which
  // actually contains the user code.
  if (!func.IsAsyncFunction() && !func.IsAsyncGenerator() &&
      !func.IsSyncGenerator()) {
    JSONObject range(jsarr);
    range.AddProperty("scriptIndex", GetScriptIndex(script));
    range.AddProperty("startPos", begin_pos);
    range.AddProperty("endPos", end_pos);
    range.AddProperty("compiled", true);  // bytecode or code.

    if (IsReportRequested(kCallSites)) {
      PrintCallSitesData(&range, func, code);
    }
    if (IsReportRequested(kCoverage)) {
      PrintCoverageData(&range, func, code);
    }
    if (IsReportRequested(kPossibleBreakpoints)) {
      PrintPossibleBreakpointsData(&range, func, code);
    }
    if (IsReportRequested(kProfile)) {
      ProfileFunction* profile_function = profile_.FindFunction(func);
      if ((profile_function != NULL) &&
          (profile_function->NumSourcePositions() > 0)) {
        PrintProfileData(&range, profile_function);
      }
    }
  }

  // Visit the closures declared in a bytecode function by traversing its object
  // pool, because they do not appear in the object store's list of closures.
  // Since local functions share the object pool, only traverse the pool once,
  // i.e. when func is the outermost function.
  if (!bytecode.IsNull() && !func.IsLocalFunction()) {
    const ObjectPool& pool = ObjectPool::Handle(zone(), bytecode.object_pool());
    Object& object = Object::Handle(zone());
    Function& closure = Function::Handle(zone());
    for (intptr_t i = 0; i < pool.Length(); i++) {
      ObjectPool::EntryType entry_type = pool.TypeAt(i);
      if (entry_type != ObjectPool::EntryType::kTaggedObject) {
        continue;
      }
      object = pool.ObjectAt(i);
      if (object.IsFunction()) {
        closure ^= object.raw();
        if (closure.kind() == RawFunction::kClosureFunction &&
            closure.IsLocalFunction()) {
          VisitFunction(jsarr, closure);
        }
      }
    }
  }
}

void SourceReport::VisitField(JSONArray* jsarr, const Field& field) {
  if (ShouldSkipField(field) || !field.HasInitializerFunction()) return;
  const Function& func = Function::Handle(field.InitializerFunction());
  VisitFunction(jsarr, func);
}

void SourceReport::VisitLibrary(JSONArray* jsarr, const Library& lib) {
  Class& cls = Class::Handle(zone());
  Array& functions = Array::Handle(zone());
  Array& fields = Array::Handle(zone());
  Function& func = Function::Handle(zone());
  Field& field = Field::Handle(zone());
  Script& script = Script::Handle(zone());
  ClassDictionaryIterator it(lib, ClassDictionaryIterator::kIteratePrivate);
  while (it.HasNext()) {
    cls = it.GetNextClass();
    if (!cls.is_finalized()) {
      if (compile_mode_ == kForceCompile) {
        Error& err = Error::Handle(cls.EnsureIsFinalized(thread()));
        if (!err.IsNull()) {
          // Emit an uncompiled range for this class with error information.
          JSONObject range(jsarr);
          script = cls.script();
          range.AddProperty("scriptIndex", GetScriptIndex(script));
          range.AddProperty("startPos", cls.token_pos());
          range.AddProperty("endPos", cls.end_token_pos());
          range.AddProperty("compiled", false);
          range.AddProperty("error", err);
          continue;
        }
        ASSERT(cls.is_finalized());
      } else {
        cls.EnsureDeclarationLoaded();
        // Emit one range for the whole uncompiled class.
        JSONObject range(jsarr);
        script = cls.script();
        range.AddProperty("scriptIndex", GetScriptIndex(script));
        range.AddProperty("startPos", cls.token_pos());
        range.AddProperty("endPos", cls.end_token_pos());
        range.AddProperty("compiled", false);
        continue;
      }
    }

    functions = cls.functions();
    for (int i = 0; i < functions.Length(); i++) {
      func ^= functions.At(i);
      VisitFunction(jsarr, func);
    }

    fields = cls.fields();
    for (intptr_t i = 0; i < fields.Length(); i++) {
      field ^= fields.At(i);
      VisitField(jsarr, field);
    }
  }
}

void SourceReport::VisitClosures(JSONArray* jsarr) {
  // Note that closures declared in bytecode are not visited here, but in
  // VisitFunction while traversing the object pool of their owner functions.
  const GrowableObjectArray& closures = GrowableObjectArray::Handle(
      thread()->isolate()->object_store()->closure_functions());

  // We need to keep rechecking the length of the closures array, as handling
  // a closure potentially adds new entries to the end.
  Function& func = Function::Handle(zone());
  for (int i = 0; i < closures.Length(); i++) {
    func ^= closures.At(i);
    VisitFunction(jsarr, func);
  }
}

void SourceReport::PrintJSON(JSONStream* js,
                             const Script& script,
                             TokenPosition start_pos,
                             TokenPosition end_pos) {
  Init(Thread::Current(), &script, start_pos, end_pos);

  JSONObject report(js);
  report.AddProperty("type", "SourceReport");
  {
    JSONArray ranges(&report, "ranges");

    const GrowableObjectArray& libs = GrowableObjectArray::Handle(
        zone(), thread()->isolate()->object_store()->libraries());

    // We only visit the libraries which actually load the specified script.
    Library& lib = Library::Handle(zone());
    for (int i = 0; i < libs.Length(); i++) {
      lib ^= libs.At(i);
      if (script.IsNull() || ScriptIsLoadedByLibrary(script, lib)) {
        VisitLibrary(&ranges, lib);
      }
    }

    // Visit all closures for this isolate.
    VisitClosures(&ranges);
  }

  // Print the script table.
  JSONArray scripts(&report, "scripts");
  PrintScriptTable(&scripts);
}

}  // namespace dart
#endif  // !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)