//===--- ImageInspectionWin32.cpp - Win32 image inspection ----------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

#if !defined(__ELF__) && !defined(__MACH__)

#include "ImageInspection.h"

#if defined(__CYGWIN__)
#include <dlfcn.h>
#elif defined(_WIN32)
#define WIN32_LEAN_AND_MEAN
#define NOMINMAX
#include <Windows.h>
#include <DbgHelp.h>
#endif

#include "swift/Runtime/Mutex.h"

using namespace swift;

int swift::lookupSymbol(const void *address, SymbolInfo *info) {
#if defined(__CYGWIN__)
  Dl_info dlinfo;
  if (dladdr(address, &dlinfo) == 0) {
    return 0;
  }

  info->fileName = dlinfo.dli_fname;
  info->baseAddress = dlinfo.dli_fbase;
  info->symbolName = dli_info.dli_sname;
  info->symbolAddress = dli_saddr;
  return 1;
#elif defined(_WIN32)
  return _swift_withWin32DbgHelpLibrary([&] (bool isInitialized) {
    static const constexpr size_t kSymbolMaxNameLen = 1024;

    if (!isInitialized) {
      return 0;
    }

    char buffer[sizeof(SYMBOL_INFO) + kSymbolMaxNameLen];
    PSYMBOL_INFO pSymbol = reinterpret_cast<PSYMBOL_INFO>(buffer);
    pSymbol->SizeOfStruct = sizeof(SYMBOL_INFO);
    pSymbol->MaxNameLen = kSymbolMaxNameLen;

    DWORD64 dwDisplacement = 0;

    if (SymFromAddr(GetCurrentProcess(),
                    reinterpret_cast<const DWORD64>(address),
                    &dwDisplacement, pSymbol) == FALSE) {
      return 0;
    }

    info->fileName = NULL;
    info->baseAddress = reinterpret_cast<void *>(pSymbol->ModBase);
    info->symbolName.reset(_strdup(pSymbol->Name));
    info->symbolAddress = reinterpret_cast<void *>(pSymbol->Address);

    return 1;
  });
#else
  return 0;
#endif // defined(__CYGWIN__) || defined(_WIN32)
}

#if defined(_WIN32)
static StaticMutex mutex;
static bool isDbgHelpInitialized = false;

void swift::_swift_withWin32DbgHelpLibrary(
  const std::function<void(bool /* isInitialized */)>& body) {
  mutex.withLock([&body] () {
    if (!isDbgHelpInitialized) {
      SymSetOptions(SYMOPT_UNDNAME | SYMOPT_DEFERRED_LOADS);
      isDbgHelpInitialized = SymInitialize(GetCurrentProcess(), nullptr, true);
    }
    body(isDbgHelpInitialized);
  });
}
#endif

#endif // !defined(__ELF__) && !defined(__MACH__)