text: // Copyright 2006-2008 the V8 project authors. All rights reserved.
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  //       notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  //       copyright notice, this list of conditions and the following
  //       disclaimer in the documentation and/or other materials provided
  //       with the distribution.
  //     * Neither the name of Google Inc. nor the names of its
  //       contributors may be used to endorse or promote products derived
  //       from this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #include <ctype.h>
  #include <stdlib.h>
  
  #include "v8.h"
  
  #include "platform.h"
  #include "smart-pointer.h"
  #include "string-stream.h"
  
  
  namespace v8 {
  namespace internal {
  
  // Define all of our flags.
  #define FLAG_MODE_DEFINE
  #include "flag-definitions.h"
  
  // Define all of our flags default values.
  #define FLAG_MODE_DEFINE_DEFAULTS
  #include "flag-definitions.h"
  
  namespace {
  
  // This structure represents a single entry in the flag system, with a pointer
  // to the actual flag, default value, comment, etc.  This is designed to be POD
  // initialized as to avoid requiring static constructors.
  struct Flag {
    enum FlagType { TYPE_BOOL, TYPE_INT, TYPE_FLOAT, TYPE_STRING, TYPE_ARGS };
  
    FlagType type_;           // What type of flag, bool, int, or string.
    const char* name_;        // Name of the flag, ex "my_flag".
    void* valptr_;            // Pointer to the global flag variable.
    const void* defptr_;      // Pointer to the default value.
    const char* cmt_;         // A comment about the flags purpose.
    bool owns_ptr_;           // Does the flag own its string value?
  
    FlagType type() const { return type_; }
  
    const char* name() const { return name_; }
  
    const char* comment() const { return cmt_; }
  
    bool* bool_variable() const {
      ASSERT(type_ == TYPE_BOOL);
      return reinterpret_cast<bool*>(valptr_);
    }
  
    int* int_variable() const {
      ASSERT(type_ == TYPE_INT);
      return reinterpret_cast<int*>(valptr_);
    }
  
    double* float_variable() const {
      ASSERT(type_ == TYPE_FLOAT);
      return reinterpret_cast<double*>(valptr_);
    }
  
    const char* string_value() const {
      ASSERT(type_ == TYPE_STRING);
      return *reinterpret_cast<const char**>(valptr_);
    }
  
    void set_string_value(const char* value, bool owns_ptr) {
      ASSERT(type_ == TYPE_STRING);
      const char** ptr = reinterpret_cast<const char**>(valptr_);
      if (owns_ptr_ && *ptr != NULL) DeleteArray(*ptr);
      *ptr = value;
      owns_ptr_ = owns_ptr;
    }
  
    JSArguments* args_variable() const {
      ASSERT(type_ == TYPE_ARGS);
      return reinterpret_cast<JSArguments*>(valptr_);
    }
  
    bool bool_default() const {
      ASSERT(type_ == TYPE_BOOL);
      return *reinterpret_cast<const bool*>(defptr_);
    }
  
    int int_default() const {
      ASSERT(type_ == TYPE_INT);
      return *reinterpret_cast<const int*>(defptr_);
    }
  
    double float_default() const {
      ASSERT(type_ == TYPE_FLOAT);
      return *reinterpret_cast<const double*>(defptr_);
    }
  
    const char* string_default() const {
      ASSERT(type_ == TYPE_STRING);
      return *reinterpret_cast<const char* const *>(defptr_);
    }
  
    JSArguments args_default() const {
      ASSERT(type_ == TYPE_ARGS);
      return *reinterpret_cast<const JSArguments*>(defptr_);
    }
  
    // Compare this flag's current value against the default.
    bool IsDefault() const {
      switch (type_) {
        case TYPE_BOOL:
          return *bool_variable() == bool_default();
        case TYPE_INT:
          return *int_variable() == int_default();
        case TYPE_FLOAT:
          return *float_variable() == float_default();
        case TYPE_STRING: {
          const char* str1 = string_value();
          const char* str2 = string_default();
          if (str2 == NULL) return str1 == NULL;
          if (str1 == NULL) return str2 == NULL;
          return strcmp(str1, str2) == 0;
        }
        case TYPE_ARGS:
          return args_variable()->argc() == 0;
      }
      UNREACHABLE();
      return true;
    }
  
    // Set a flag back to it's default value.
    void Reset() {
      switch (type_) {
        case TYPE_BOOL:
          *bool_variable() = bool_default();
          break;
        case TYPE_INT:
          *int_variable() = int_default();
          break;
        case TYPE_FLOAT:
          *float_variable() = float_default();
          break;
        case TYPE_STRING:
          set_string_value(string_default(), false);
          break;
        case TYPE_ARGS:
          *args_variable() = args_default();
          break;
      }
    }
  };
  
  Flag flags[] = {
  #define FLAG_MODE_META
  #include "flag-definitions.h"
  };
  
  const size_t num_flags = sizeof(flags) / sizeof(*flags);
  
  }  // namespace
  
  
  static const char* Type2String(Flag::FlagType type) {
    switch (type) {
      case Flag::TYPE_BOOL: return "bool";
      case Flag::TYPE_INT: return "int";
      case Flag::TYPE_FLOAT: return "float";
      case Flag::TYPE_STRING: return "string";
      case Flag::TYPE_ARGS: return "arguments";
    }
    UNREACHABLE();
    return NULL;
  }
  
  
  static SmartPointer<const char> ToString(Flag* flag) {
    HeapStringAllocator string_allocator;
    StringStream buffer(&string_allocator);
    switch (flag->type()) {
      case Flag::TYPE_BOOL:
        buffer.Add("%s", (*flag->bool_variable() ? "true" : "false"));
        break;
      case Flag::TYPE_INT:
        buffer.Add("%d", *flag->int_variable());
        break;
      case Flag::TYPE_FLOAT:
        buffer.Add("%f", FmtElm(*flag->float_variable()));
        break;
      case Flag::TYPE_STRING: {
        const char* str = flag->string_value();
        buffer.Add("%s", str ? str : "NULL");
        break;
      }
      case Flag::TYPE_ARGS: {
        JSArguments args = *flag->args_variable();
        if (args.argc() > 0) {
          buffer.Add("%s",  args[0]);
          for (int i = 1; i < args.argc(); i++) {
            buffer.Add(" %s", args[i]);
          }
        }
        break;
      }
    }
    return buffer.ToCString();
  }
  
  
  // static
  List<const char*>* FlagList::argv() {
    List<const char*>* args = new List<const char*>(8);
    Flag* args_flag = NULL;
    for (size_t i = 0; i < num_flags; ++i) {
      Flag* f = &flags[i];
      if (!f->IsDefault()) {
        if (f->type() == Flag::TYPE_ARGS) {
          ASSERT(args_flag == NULL);
          args_flag = f;  // Must be last in arguments.
          continue;
        }
        HeapStringAllocator string_allocator;
        StringStream buffer(&string_allocator);
        if (f->type() != Flag::TYPE_BOOL || *(f->bool_variable())) {
          buffer.Add("--%s", f->name());
        } else {
          buffer.Add("--no%s", f->name());
        }
        args->Add(buffer.ToCString().Detach());
        if (f->type() != Flag::TYPE_BOOL) {
          args->Add(ToString(f).Detach());
        }
      }
    }
    if (args_flag != NULL) {
      HeapStringAllocator string_allocator;
      StringStream buffer(&string_allocator);
      buffer.Add("--%s", args_flag->name());
      args->Add(buffer.ToCString().Detach());
      JSArguments jsargs = *args_flag->args_variable();
      for (int j = 0; j < jsargs.argc(); j++) {
        args->Add(StrDup(jsargs[j]));
      }
    }
    return args;
  }
  
  
  // Helper function to parse flags: Takes an argument arg and splits it into
  // a flag name and flag value (or NULL if they are missing). is_bool is set
  // if the arg started with "-no" or "--no". The buffer may be used to NUL-
  // terminate the name, it must be large enough to hold any possible name.
  static void SplitArgument(const char* arg,
                            char* buffer,
                            int buffer_size,
                            const char** name,
                            const char** value,
                            bool* is_bool) {
    *name = NULL;
    *value = NULL;
    *is_bool = false;
  
    if (*arg == '-') {
      // find the begin of the flag name
      arg++;  // remove 1st '-'
      if (*arg == '-') {
        arg++;  // remove 2nd '-'
        if (arg[0] == '\0') {
          const char* kJSArgumentsFlagName = "js_arguments";
          *name = kJSArgumentsFlagName;
          return;
        }
      }
      if (arg[0] == 'n' && arg[1] == 'o') {
        arg += 2;  // remove "no"
        *is_bool = true;
      }
      *name = arg;
  
      // find the end of the flag name
      while (*arg != '\0' && *arg != '=')
        arg++;
  
      // get the value if any
      if (*arg == '=') {
        // make a copy so we can NUL-terminate flag name
        size_t n = arg - *name;
        CHECK(n < static_cast<size_t>(buffer_size));  // buffer is too small
        memcpy(buffer, *name, n);
        buffer[n] = '\0';
        *name = buffer;
        // get the value
        *value = arg + 1;
      }
    }
  }
  
  
  inline char NormalizeChar(char ch) {
    return ch == '_' ? '-' : ch;
  }
  
  
  static bool EqualNames(const char* a, const char* b) {
    for (int i = 0; NormalizeChar(a[i]) == NormalizeChar(b[i]); i++) {
      if (a[i] == '\0') {
        return true;
      }
    }
    return false;
  }
  
  
  static Flag* FindFlag(const char* name) {
    for (size_t i = 0; i < num_flags; ++i) {
      if (EqualNames(name, flags[i].name()))
        return &flags[i];
    }
    return NULL;
  }
  
  
  // static
  int FlagList::SetFlagsFromCommandLine(int* argc,
                                        char** argv,
                                        bool remove_flags) {
    // parse arguments
    for (int i = 1; i < *argc;) {
      int j = i;  // j > 0
      const char* arg = argv[i++];
  
      // split arg into flag components
      char buffer[1*KB];
      const char* name;
      const char* value;
      bool is_bool;
      SplitArgument(arg, buffer, sizeof buffer, &name, &value, &is_bool);
  
      if (name != NULL) {
        // lookup the flag
        Flag* flag = FindFlag(name);
        if (flag == NULL) {
          if (remove_flags) {
            // We don't recognize this flag but since we're removing
            // the flags we recognize we assume that the remaining flags
            // will be processed somewhere else so this flag might make
            // sense there.
            continue;
          } else {
            fprintf(stderr, "Error: unrecognized flag %s\n"
                    "Try --help for options\n", arg);
            return j;
          }
        }
  
        // if we still need a flag value, use the next argument if available
        if (flag->type() != Flag::TYPE_BOOL &&
            flag->type() != Flag::TYPE_ARGS &&
            value == NULL) {
          if (i < *argc) {
            value = argv[i++];
          } else {
            fprintf(stderr, "Error: missing value for flag %s of type %s\n"
                    "Try --help for options\n",
                    arg, Type2String(flag->type()));
            return j;
          }
        }
  
        // set the flag
        char* endp = const_cast<char*>("");  // *endp is only read
        switch (flag->type()) {
          case Flag::TYPE_BOOL:
            *flag->bool_variable() = !is_bool;
            break;
          case Flag::TYPE_INT:
            *flag->int_variable() = strtol(value, &endp, 10);  // NOLINT
            break;
          case Flag::TYPE_FLOAT:
            *flag->float_variable() = strtod(value, &endp);
            break;
          case Flag::TYPE_STRING:
            flag->set_string_value(value ? StrDup(value) : NULL, true);
            break;
          case Flag::TYPE_ARGS: {
            int start_pos = (value == NULL) ? i : i - 1;
            int js_argc = *argc - start_pos;
            const char** js_argv = NewArray<const char*>(js_argc);
            if (value != NULL) {
              js_argv[0] = StrDup(value);
            }
            for (int k = i; k < *argc; k++) {
              js_argv[k - start_pos] = StrDup(argv[k]);
            }
            *flag->args_variable() = JSArguments(js_argc, js_argv);
            i = *argc;  // Consume all arguments
            break;
          }
        }
  
        // handle errors
        if ((flag->type() == Flag::TYPE_BOOL && value != NULL) ||
            (flag->type() != Flag::TYPE_BOOL && is_bool) ||
            *endp != '\0') {
          fprintf(stderr, "Error: illegal value for flag %s of type %s\n"
                  "Try --help for options\n",
                  arg, Type2String(flag->type()));
          return j;
        }
  
        // remove the flag & value from the command
        if (remove_flags) {
          while (j < i) {
            argv[j++] = NULL;
          }
        }
      }
    }
  
    // shrink the argument list
    if (remove_flags) {
      int j = 1;
      for (int i = 1; i < *argc; i++) {
        if (argv[i] != NULL)
          argv[j++] = argv[i];
      }
      *argc = j;
    }
  
    if (FLAG_help) {
      PrintHelp();
      exit(0);
    }
    // parsed all flags successfully
    return 0;
  }
  
  
  static char* SkipWhiteSpace(char* p) {
    while (*p != '\0' && isspace(*p) != 0) p++;
    return p;
  }
  
  
  static char* SkipBlackSpace(char* p) {
    while (*p != '\0' && isspace(*p) == 0) p++;
    return p;
  }
  
  
  // static
  int FlagList::SetFlagsFromString(const char* str, int len) {
    // make a 0-terminated copy of str
    char* copy0 = NewArray<char>(len + 1);
    memcpy(copy0, str, len);
    copy0[len] = '\0';
  
    // strip leading white space
    char* copy = SkipWhiteSpace(copy0);
  
    // count the number of 'arguments'
    int argc = 1;  // be compatible with SetFlagsFromCommandLine()
    for (char* p = copy; *p != '\0'; argc++) {
      p = SkipBlackSpace(p);
      p = SkipWhiteSpace(p);
    }
  
    // allocate argument array
    char** argv = NewArray<char*>(argc);
  
    // split the flags string into arguments
    argc = 1;  // be compatible with SetFlagsFromCommandLine()
    for (char* p = copy; *p != '\0'; argc++) {
      argv[argc] = p;
      p = SkipBlackSpace(p);
      if (*p != '\0') *p++ = '\0';  // 0-terminate argument
      p = SkipWhiteSpace(p);
    }
  
    // set the flags
    int result = SetFlagsFromCommandLine(&argc, argv, false);
  
    // cleanup
    DeleteArray(argv);
    DeleteArray(copy0);
  
    return result;
  }
  
  
  // static
  void FlagList::ResetAllFlags() {
    for (size_t i = 0; i < num_flags; ++i) {
      flags[i].Reset();
    }
  }
  
  
  // static
  void FlagList::PrintHelp() {
    printf("Usage:\n");
    printf("  shell [options] -e string\n");
    printf("    execute string in V8\n");
    printf("  shell [options] file1 file2 ... filek\n");
    printf("    run JavaScript scripts in file1, file2, ..., filek\n");
    printf("  shell [options]\n");
    printf("  shell [options] --shell [file1 file2 ... filek]\n");
    printf("    run an interactive JavaScript shell\n");
    printf("  d8 [options] file1 file2 ... filek\n");
    printf("  d8 [options]\n");
    printf("  d8 [options] --shell [file1 file2 ... filek]\n");
    printf("    run the new debugging shell\n\n");
    printf("Options:\n");
    for (size_t i = 0; i < num_flags; ++i) {
      Flag* f = &flags[i];
      SmartPointer<const char> value = ToString(f);
      printf("  --%s (%s)\n        type: %s  default: %s\n",
             f->name(), f->comment(), Type2String(f->type()), *value);
    }
  }
  
  JSArguments::JSArguments()
      : argc_(0), argv_(NULL) {}
  JSArguments::JSArguments(int argc, const char** argv)
      : argc_(argc), argv_(argv) {}
  int JSArguments::argc() const { return argc_; }
  const char** JSArguments::argv() { return argv_; }
  const char*& JSArguments::operator[](int idx) { return argv_[idx]; }
  JSArguments& JSArguments::operator=(JSArguments args) {
      argc_ = args.argc_;
      argv_ = args.argv_;
      return *this;
  }
  
  
  } }  // namespace v8::internal
  