//===-- ubsan_flags.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
//
//===----------------------------------------------------------------------===//
//
// Runtime flags for UndefinedBehaviorSanitizer.
//
//===----------------------------------------------------------------------===//

#include "ubsan_platform.h"
#if CAN_SANITIZE_UB
#include "ubsan_flags.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_flags.h"
#include "sanitizer_common/sanitizer_flag_parser.h"

#include <stdlib.h>

#if SANITIZER_EMSCRIPTEN
extern "C" void emscripten_builtin_free(void *);
#include <emscripten/em_asm.h>
#endif

namespace __ubsan {

static const char *GetFlag(const char *flag) {
  // We cannot call getenv() from inside a preinit array initializer
  if (SANITIZER_CAN_USE_PREINIT_ARRAY) {
    return GetEnv(flag);
  } else {
    return getenv(flag);
  }
}

Flags ubsan_flags;

void Flags::SetDefaults() {
#define UBSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
#include "ubsan_flags.inc"
#undef UBSAN_FLAG
}

void RegisterUbsanFlags(FlagParser *parser, Flags *f) {
#define UBSAN_FLAG(Type, Name, DefaultValue, Description) \
  RegisterFlag(parser, #Name, Description, &f->Name);
#include "ubsan_flags.inc"
#undef UBSAN_FLAG
}

void InitializeFlags() {
  SetCommonFlagsDefaults();
  {
    CommonFlags cf;
    cf.CopyFrom(*common_flags());
    cf.print_summary = false;
#if !SANITIZER_EMSCRIPTEN
    // getenv on emscripten uses malloc, which we can't when using some sanitizers.
    // You can't run external symbolizers anyway.
    cf.external_symbolizer_path = GetFlag("UBSAN_SYMBOLIZER_PATH");
#endif
    OverrideCommonFlags(cf);
  }

  Flags *f = flags();
  f->SetDefaults();

  FlagParser parser;
  RegisterCommonFlags(&parser);
  RegisterUbsanFlags(&parser, f);

  // Override from user-specified string.
  parser.ParseString(__ubsan_default_options());
  // Override from environment variable.
#if SANITIZER_EMSCRIPTEN
#ifdef __wasm64__
    // FIXME: support UBSAN in wasm64.
    abort();
#else
  char *options = (char*) EM_ASM_INT({
    return withBuiltinMalloc(function () {
      return allocateUTF8(Module['UBSAN_OPTIONS'] || 0);
    });
  });
  parser.ParseString(options);
  emscripten_builtin_free(options);
#endif
#else
  parser.ParseStringFromEnv("UBSAN_OPTIONS");
#endif // SANITIZER_EMSCRIPTEN

  InitializeCommonFlags();
  if (Verbosity()) ReportUnrecognizedFlags();

  if (common_flags()->help) parser.PrintFlagDescriptions();
}

}  // namespace __ubsan

SANITIZER_INTERFACE_WEAK_DEF(const char *, __ubsan_default_options, void) {
  return "";
}

#endif  // CAN_SANITIZE_UB
