//===-- sanitizer_symbolizer_win.cc ---------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is shared between AddressSanitizer and ThreadSanitizer
// run-time libraries.
// Windows-specific implementation of symbolizer parts.
//===----------------------------------------------------------------------===//

#include "sanitizer_platform.h"
#if SANITIZER_WINDOWS
#include <windows.h>
#include <dbghelp.h>
#pragma comment(lib, "dbghelp.lib")

#include "sanitizer_symbolizer_win.h"
#include "sanitizer_symbolizer_internal.h"

namespace __sanitizer {

namespace {

bool is_dbghelp_initialized = false;

bool TrySymInitialize() {
  SymSetOptions(SYMOPT_DEFERRED_LOADS | SYMOPT_UNDNAME | SYMOPT_LOAD_LINES);
  return SymInitialize(GetCurrentProcess(), 0, TRUE);
  // FIXME: We don't call SymCleanup() on exit yet - should we?
}

// Initializes DbgHelp library, if it's not yet initialized. Calls to this
// function should be synchronized with respect to other calls to DbgHelp API
// (e.g. from WinSymbolizerTool).
void InitializeDbgHelpIfNeeded() {
  if (is_dbghelp_initialized)
    return;
  if (!TrySymInitialize()) {
    // OK, maybe the client app has called SymInitialize already.
    // That's a bit unfortunate for us as all the DbgHelp functions are
    // single-threaded and we can't coordinate with the app.
    // FIXME: Can we stop the other threads at this point?
    // Anyways, we have to reconfigure stuff to make sure that SymInitialize
    // has all the appropriate options set.
    // Cross our fingers and reinitialize DbgHelp.
    Report("*** WARNING: Failed to initialize DbgHelp!              ***\n");
    Report("*** Most likely this means that the app is already      ***\n");
    Report("*** using DbgHelp, possibly with incompatible flags.    ***\n");
    Report("*** Due to technical reasons, symbolization might crash ***\n");
    Report("*** or produce wrong results.                           ***\n");
    SymCleanup(GetCurrentProcess());
    TrySymInitialize();
  }
  is_dbghelp_initialized = true;

  // When an executable is run from a location different from the one where it
  // was originally built, we may not see the nearby PDB files.
  // To work around this, let's append the directory of the main module
  // to the symbol search path.  All the failures below are not fatal.
  const size_t kSymPathSize = 2048;
  static wchar_t path_buffer[kSymPathSize + 1 + MAX_PATH];
  if (!SymGetSearchPathW(GetCurrentProcess(), path_buffer, kSymPathSize)) {
    Report("*** WARNING: Failed to SymGetSearchPathW ***\n");
    return;
  }
  size_t sz = wcslen(path_buffer);
  if (sz) {
    CHECK_EQ(0, wcscat_s(path_buffer, L";"));
    sz++;
  }
  DWORD res = GetModuleFileNameW(NULL, path_buffer + sz, MAX_PATH);
  if (res == 0 || res == MAX_PATH) {
    Report("*** WARNING: Failed to getting the EXE directory ***\n");
    return;
  }
  // Write the zero character in place of the last backslash to get the
  // directory of the main module at the end of path_buffer.
  wchar_t *last_bslash = wcsrchr(path_buffer + sz, L'\\');
  CHECK_NE(last_bslash, 0);
  *last_bslash = L'\0';
  if (!SymSetSearchPathW(GetCurrentProcess(), path_buffer)) {
    Report("*** WARNING: Failed to SymSetSearchPathW\n");
    return;
  }
}

}  // namespace

bool WinSymbolizerTool::SymbolizePC(uptr addr, SymbolizedStack *frame) {
  InitializeDbgHelpIfNeeded();

  // See http://msdn.microsoft.com/en-us/library/ms680578(VS.85).aspx
  char buffer[sizeof(SYMBOL_INFO) + MAX_SYM_NAME * sizeof(CHAR)];
  PSYMBOL_INFO symbol = (PSYMBOL_INFO)buffer;
  symbol->SizeOfStruct = sizeof(SYMBOL_INFO);
  symbol->MaxNameLen = MAX_SYM_NAME;
  DWORD64 offset = 0;
  BOOL got_objname = SymFromAddr(GetCurrentProcess(),
                                 (DWORD64)addr, &offset, symbol);
  if (!got_objname)
    return false;

  DWORD unused;
  IMAGEHLP_LINE64 line_info;
  line_info.SizeOfStruct = sizeof(IMAGEHLP_LINE64);
  BOOL got_fileline = SymGetLineFromAddr64(GetCurrentProcess(), (DWORD64)addr,
                                           &unused, &line_info);
  frame->info.function = internal_strdup(symbol->Name);
  frame->info.function_offset = (uptr)offset;
  if (got_fileline) {
    frame->info.file = internal_strdup(line_info.FileName);
    frame->info.line = line_info.LineNumber;
  }
  return true;
}

const char *WinSymbolizerTool::Demangle(const char *name) {
  CHECK(is_dbghelp_initialized);
  static char demangle_buffer[1000];
  if (name[0] == '\01' &&
      UnDecorateSymbolName(name + 1, demangle_buffer, sizeof(demangle_buffer),
                           UNDNAME_NAME_ONLY))
    return demangle_buffer;
  else
    return name;
}

bool FindModuleNameAndOffsetForAddress(uptr addr, const char **module_name,
                                       uptr *module_offset) {
  InitializeDbgHelpIfNeeded();

  IMAGEHLP_MODULE64 mod_info;
  internal_memset(&mod_info, 0, sizeof(mod_info));
  mod_info.SizeOfStruct = sizeof(mod_info);
  if (SymGetModuleInfo64(GetCurrentProcess(), addr, &mod_info)) {
    *module_name = mod_info.ImageName;
    *module_offset = addr - (uptr)mod_info.BaseOfImage;
    return true;
  }
  return false;
}

// TODO(kuba.brecka): To be merged with POSIXSymbolizer.
class WinSymbolizer : public Symbolizer {
 public:
  explicit WinSymbolizer(IntrusiveList<SymbolizerTool> tools)
      : Symbolizer(tools) {}

 private:
  bool PlatformFindModuleNameAndOffsetForAddress(
      uptr addr, const char **module_name, uptr *module_offset) override {
    return ::FindModuleNameAndOffsetForAddress(addr, module_name,
                                               module_offset);
  }
  const char *PlatformDemangle(const char *name) override { return name; }
  void PlatformPrepareForSandboxing() override { }
};

Symbolizer *Symbolizer::PlatformInit() {
  IntrusiveList<SymbolizerTool> list;
  list.clear();
  list.push_back(new(symbolizer_allocator_) WinSymbolizerTool());
  return new(symbolizer_allocator_) WinSymbolizer(list);
}

}  // namespace __sanitizer

#endif  // _WIN32