root/src/flags.cc

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DEFINITIONS

This source file includes following definitions.
  1. Type2String
  2. ToString
  3. argv
  4. SplitArgument
  5. NormalizeChar
  6. EqualNames
  7. FindFlag
  8. SetFlagsFromCommandLine
  9. SkipWhiteSpace
  10. SkipBlackSpace
  11. SetFlagsFromString
  12. ResetAllFlags
  13. PrintHelp
  14. EnforceFlagImplications

// 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-array-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 SmartArrayPointer<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 != NULL && *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) {
  int return_code = 0;
  // 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_code = j;
          break;
        }
      }

      // 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_code = j;
          break;
        }
      }

      // 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::Create(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_code = j;
        break;
      }

      // 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 return_code;
}


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
  ScopedVector<char> copy0(len + 1);
  memcpy(copy0.start(), str, len);
  copy0[len] = '\0';

  // strip leading white space
  char* copy = SkipWhiteSpace(copy0.start());

  // 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
  ScopedVector<char*> argv(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.start(), false);

  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];
    SmartArrayPointer<const char> value = ToString(f);
    printf("  --%s (%s)\n        type: %s  default: %s\n",
           f->name(), f->comment(), Type2String(f->type()), *value);
  }
}


void FlagList::EnforceFlagImplications() {
#define FLAG_MODE_DEFINE_IMPLICATIONS
#include "flag-definitions.h"
}

} }  // namespace v8::internal

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