//===--- Statistic.cpp - Swift unified stats reporting --------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

#include "swift/Basic/Statistic.h"
#include "swift/Driver/DependencyGraph.h"
#include "llvm/Config/config.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/raw_ostream.h"
#include <chrono>

#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif

namespace swift {
using namespace llvm;
using namespace llvm::sys;

static size_t
getChildrenMaxResidentSetSize() {
#if defined(HAVE_GETRUSAGE) && !defined(__HAIKU__)
  struct rusage RU;
  ::getrusage(RUSAGE_CHILDREN, &RU);
  return RU.ru_maxrss;
#else
  return 0;
#endif
}

static std::string
makeFileName(StringRef Prefix,
             StringRef ProgramName,
             StringRef AuxName,
             StringRef Suffix) {
  std::string tmp;
  raw_string_ostream stream(tmp);
  auto now = std::chrono::system_clock::now();
  stream << Prefix
         << "-" << now.time_since_epoch().count()
         << "-" << ProgramName
         << "-" << AuxName
         << "-" << Process::GetRandomNumber()
         << "." << Suffix;
  return stream.str();
}

static std::string
makeStatsFileName(StringRef ProgramName,
                  StringRef AuxName) {
  return makeFileName("stats", ProgramName, AuxName, "json");
}

static std::string
makeTraceFileName(StringRef ProgramName,
                  StringRef AuxName) {
  return makeFileName("trace", ProgramName, AuxName, "csv");
}

// LLVM's statistics-reporting machinery is sensitive to filenames containing
// YAML-quote-requiring characters, which occur surprisingly often in the wild;
// we only need a recognizable and likely-unique name for a target here, not an
// exact filename, so we go with a crude approximation. Furthermore, to avoid
// parse ambiguities when "demangling" counters and filenames we exclude hyphens
// and slashes.
static std::string
cleanName(StringRef n) {
  std::string tmp;
  for (auto c : n) {
    if (('a' <= c && c <= 'z') ||
        ('A' <= c && c <= 'Z') ||
        ('0' <= c && c <= '9') ||
        (c == '.'))
      tmp += c;
    else
      tmp += '_';
  }
  return tmp;
}

static std::string
auxName(StringRef ModuleName,
        StringRef InputName,
        StringRef TripleName,
        StringRef OutputType,
        StringRef OptType) {
  if (InputName.empty()) {
    InputName = "all";
  }
  if (OptType.empty()) {
    InputName = "Onone";
  }
  if (!OutputType.empty() && OutputType.front() == '.') {
    OutputType = OutputType.substr(1);
  }
  if (!OptType.empty() && OptType.front() == '-') {
    OptType = OptType.substr(1);
  }
  return (cleanName(ModuleName)
          + "-" + cleanName(InputName)
          + "-" + cleanName(TripleName)
          + "-" + cleanName(OutputType)
          + "-" + cleanName(OptType));
}

UnifiedStatsReporter::UnifiedStatsReporter(StringRef ProgramName,
                                           StringRef ModuleName,
                                           StringRef InputName,
                                           StringRef TripleName,
                                           StringRef OutputType,
                                           StringRef OptType,
                                           StringRef Directory,
                                           SourceManager *SM,
                                           bool TraceEvents)
  : UnifiedStatsReporter(ProgramName,
                         auxName(ModuleName,
                                 InputName,
                                 TripleName,
                                 OutputType,
                                 OptType),
                         Directory,
                         SM, TraceEvents)
{
}

UnifiedStatsReporter::UnifiedStatsReporter(StringRef ProgramName,
                                           StringRef AuxName,
                                           StringRef Directory,
                                           SourceManager *SM,
                                           bool TraceEvents)
  : StatsFilename(Directory),
    TraceFilename(Directory),
    StartedTime(llvm::TimeRecord::getCurrentTime()),
    Timer(make_unique<NamedRegionTimer>(AuxName,
                                        "Building Target",
                                        ProgramName, "Running Program")),
    SourceMgr(SM)
{
  path::append(StatsFilename, makeStatsFileName(ProgramName, AuxName));
  path::append(TraceFilename, makeTraceFileName(ProgramName, AuxName));
  EnableStatistics(/*PrintOnExit=*/false);
  SharedTimer::enableCompilationTimers();
  if (TraceEvents)
    LastTracedFrontendCounters = make_unique<AlwaysOnFrontendCounters>();
}

UnifiedStatsReporter::AlwaysOnDriverCounters &
UnifiedStatsReporter::getDriverCounters()
{
  if (!DriverCounters)
    DriverCounters = make_unique<AlwaysOnDriverCounters>();
  return *DriverCounters;
}

UnifiedStatsReporter::AlwaysOnFrontendCounters &
UnifiedStatsReporter::getFrontendCounters()
{
  if (!FrontendCounters)
    FrontendCounters = make_unique<AlwaysOnFrontendCounters>();
  return *FrontendCounters;
}

UnifiedStatsReporter::AlwaysOnFrontendRecursiveSharedTimers &
UnifiedStatsReporter::getFrontendRecursiveSharedTimers() {
  if (!FrontendRecursiveSharedTimers)
    FrontendRecursiveSharedTimers =
        make_unique<AlwaysOnFrontendRecursiveSharedTimers>();
  return *FrontendRecursiveSharedTimers;
}

void
UnifiedStatsReporter::publishAlwaysOnStatsToLLVM() {
  if (FrontendCounters) {
    auto &C = getFrontendCounters();
#define FRONTEND_STATISTIC(TY, NAME)                            \
    do {                                                        \
      static Statistic Stat = {#TY, #NAME, #NAME, {0}, false};  \
      Stat += (C).NAME;                                         \
    } while (0);
#include "swift/Basic/Statistics.def"
#undef FRONTEND_STATISTIC
  }
  if (DriverCounters) {
    auto &C = getDriverCounters();
#define DRIVER_STATISTIC(NAME)                                       \
    do {                                                             \
      static Statistic Stat = {"Driver", #NAME, #NAME, {0}, false};  \
      Stat += (C).NAME;                                              \
    } while (0);
#include "swift/Basic/Statistics.def"
#undef DRIVER_STATISTIC
  }
}

void
UnifiedStatsReporter::printAlwaysOnStatsAndTimers(raw_ostream &OS) {
  // Adapted from llvm::PrintStatisticsJSON
  OS << "{\n";
  const char *delim = "";
  if (FrontendCounters) {
    auto &C = getFrontendCounters();
#define FRONTEND_STATISTIC(TY, NAME)                        \
    do {                                                    \
      OS << delim << "\t\"" #TY "." #NAME "\": " << C.NAME; \
      delim = ",\n";                                        \
    } while (0);
#include "swift/Basic/Statistics.def"
#undef FRONTEND_STATISTIC
  }
  if (DriverCounters) {
    auto &C = getDriverCounters();
#define DRIVER_STATISTIC(NAME)                              \
    do {                                                    \
      OS << delim << "\t\"Driver." #NAME "\": " << C.NAME;  \
      delim = ",\n";                                        \
    } while (0);
#include "swift/Basic/Statistics.def"
#undef DRIVER_STATISTIC
  }
  // Print timers.
  TimerGroup::printAllJSONValues(OS, delim);
  OS << "\n}\n";
  OS.flush();
}

UnifiedStatsReporter::FrontendStatsTracer::FrontendStatsTracer(
    StringRef Name,
    SourceRange const &Range,
    UnifiedStatsReporter *Reporter)
  : Reporter(Reporter),
    SavedTime(llvm::TimeRecord::getCurrentTime()),
    Name(Name),
    Range(Range)
{
  if (Reporter)
    Reporter->saveAnyFrontendStatsEvents(*this, true);
}

UnifiedStatsReporter::FrontendStatsTracer::FrontendStatsTracer()
  : Reporter(nullptr)
{
}

UnifiedStatsReporter::FrontendStatsTracer&
UnifiedStatsReporter::FrontendStatsTracer::operator=(
    FrontendStatsTracer&& other)
{
  Reporter = other.Reporter;
  SavedTime = other.SavedTime;
  Name = other.Name;
  Range = other.Range;
  other.Reporter = nullptr;
  return *this;
}

UnifiedStatsReporter::FrontendStatsTracer::FrontendStatsTracer(
    FrontendStatsTracer&& other)
  : Reporter(other.Reporter),
    SavedTime(other.SavedTime),
    Name(other.Name),
    Range(other.Range)
{
  other.Reporter = nullptr;
}

UnifiedStatsReporter::FrontendStatsTracer::~FrontendStatsTracer()
{
  if (Reporter)
    Reporter->saveAnyFrontendStatsEvents(*this, false);
}

UnifiedStatsReporter::FrontendStatsTracer
UnifiedStatsReporter::getStatsTracer(StringRef N,
                                     SourceRange const &R)
{
  if (LastTracedFrontendCounters)
    // Return live tracer object.
    return FrontendStatsTracer(N, R, this);
  else
    // Return inert tracer object.
    return FrontendStatsTracer();
}

void
UnifiedStatsReporter::saveAnyFrontendStatsEvents(
    FrontendStatsTracer const& T,
    bool IsEntry)
{
  if (!LastTracedFrontendCounters)
    return;
  auto Now = llvm::TimeRecord::getCurrentTime();
  auto StartUS = uint64_t(1000000.0 * T.SavedTime.getProcessTime());
  auto NowUS = uint64_t(1000000.0 * Now.getProcessTime());
  auto LiveUS = IsEntry ? 0 : NowUS - StartUS;
  auto &C = getFrontendCounters();
#define FRONTEND_STATISTIC(TY, NAME)                          \
  do {                                                        \
    auto delta = C.NAME - LastTracedFrontendCounters->NAME;   \
    static char const *name = #TY "." #NAME;                  \
    if (delta != 0) {                                         \
      LastTracedFrontendCounters->NAME = C.NAME;              \
      FrontendStatsEvents.emplace_back(FrontendStatsEvent {   \
          NowUS, LiveUS, IsEntry, T.Name, name,               \
            delta, C.NAME, T.Range});                         \
    }                                                         \
  } while (0);
#include "swift/Basic/Statistics.def"
#undef FRONTEND_STATISTIC
}

UnifiedStatsReporter::AlwaysOnFrontendRecursiveSharedTimers::
    AlwaysOnFrontendRecursiveSharedTimers()
    :
#define FRONTEND_RECURSIVE_SHARED_TIMER(ID) ID(#ID),
#include "swift/Basic/Statistics.def"
#undef FRONTEND_RECURSIVE_SHARED_TIMER
      dummyInstanceVariableToGetConstructorToParse(0) {
}

UnifiedStatsReporter::~UnifiedStatsReporter()
{
  // NB: Timer needs to be Optional<> because it needs to be destructed early;
  // LLVM will complain about double-stopping a timer if you tear down a
  // NamedRegionTimer after printing all timers. The printing routines were
  // designed with more of a global-scope, run-at-process-exit in mind, which
  // we're repurposing a bit here.
  Timer.reset();

  // We currently do this by manual TimeRecord keeping because LLVM has decided
  // not to allow access to the Timers inside NamedRegionTimers.
  auto ElapsedTime = llvm::TimeRecord::getCurrentTime();
  ElapsedTime -= StartedTime;

  if (DriverCounters) {
    auto &C = getDriverCounters();
    C.ChildrenMaxRSS = getChildrenMaxResidentSetSize();
  }

  if (FrontendCounters) {
    auto &C = getFrontendCounters();
    // Convenience calculation for crude top-level "absolute speed".
    if (C.NumSourceLines != 0 && ElapsedTime.getProcessTime() != 0.0)
      C.NumSourceLinesPerSecond = (size_t) (((double)C.NumSourceLines) /
                                            ElapsedTime.getProcessTime());
  }

  std::error_code EC;
  raw_fd_ostream ostream(StatsFilename, EC, fs::F_Append | fs::F_Text);
  if (EC)
    return;

  // We change behavior here depending on whether -DLLVM_ENABLE_STATS and/or
  // assertions were on in this build; this is somewhat subtle, but turning on
  // all stats for all of LLVM and clang is a bit more expensive and intrusive
  // than we want to be in release builds.
  //
  //  - If enabled: we copy all of our "always-on" local stats into LLVM's
  //    global statistics list, and ask LLVM to manage the printing of them.
  //
  //  - If disabled: we still have our "always-on" local stats to write, and
  //    LLVM's global _timers_ were still enabled (they're runtime-enabled, not
  //    compile-time) so we sequence printing our own stats and LLVM's timers
  //    manually.

#if !defined(NDEBUG) || defined(LLVM_ENABLE_STATS)
  publishAlwaysOnStatsToLLVM();
  PrintStatisticsJSON(ostream);
#else
  printAlwaysOnStatsAndTimers(ostream);
#endif

  if (LastTracedFrontendCounters && SourceMgr) {
    std::error_code EC;
    raw_fd_ostream tstream(TraceFilename, EC, fs::F_Append | fs::F_Text);
    if (EC)
      return;
    tstream << "Time,Live,IsEntry,EventName,CounterName,"
            << "CounterDelta,CounterValue,SourceRange\n";
    for (auto const &E : FrontendStatsEvents) {
      tstream << E.TimeUSec << ','
              << E.LiveUSec << ','
              << (E.IsEntry ? "\"entry\"," : "\"exit\",")
              << '"' << E.EventName << '"' << ','
              << '"' << E.CounterName << '"' << ','
              << E.CounterDelta << ','
              << E.CounterValue << ',';
      tstream << '"';
      E.SourceRange.print(tstream, *SourceMgr, false);
      tstream << '"' << '\n';
    }
  }
}

} // namespace swift