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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at */
#ifndef shell_jsoptparse_h
#define shell_jsoptparse_h
#include <stdio.h>
#include "js/AllocPolicy.h"
#include "js/Utility.h"
#include "js/Vector.h"
namespace js {
namespace cli {
namespace detail {
// We want to use the shell's option parser before initializing the JS engine.
// The JS malloc arena isn't available yet at this point, so we use a custom
// allocation policy that uses the system malloc instead.
class OptionAllocPolicy {
template <typename T>
T* pod_malloc(size_t numElems) {
size_t bytes;
if (MOZ_UNLIKELY(!js::CalculateAllocSize<T>(numElems, &bytes))) {
return nullptr;
return static_cast<T*>(malloc(bytes));
template <typename T>
T* pod_realloc(T* p, size_t oldSize, size_t newSize) {
size_t bytes;
if (MOZ_UNLIKELY(!js::CalculateAllocSize<T>(newSize, &bytes))) {
return nullptr;
return static_cast<T*>(realloc(p, bytes));
void reportAllocOverflow() const {}
bool checkSimulatedOOM() const { return !js::oom::ShouldFailWithOOM(); }
template <typename T>
void free_(T* p, size_t numElems = 0) {
struct BoolOption;
struct MultiStringOption;
struct ValuedOption;
struct StringOption;
struct IntOption;
enum OptionKind {
struct Option {
const char* longflag;
const char* help;
OptionKind kind;
char shortflag;
bool terminatesOptions;
Option(OptionKind kind, char shortflag, const char* longflag,
const char* help)
: longflag(longflag),
terminatesOptions(false) {}
virtual ~Option() = 0;
void setTerminatesOptions(bool enabled) { terminatesOptions = enabled; }
bool getTerminatesOptions() const { return terminatesOptions; }
virtual bool isValued() const { return false; }
/* Only some valued options are variadic (like MultiStringOptions). */
virtual bool isVariadic() const { return false; }
* For arguments, the shortflag field is used to indicate whether the
* argument is optional.
bool isOptional() { return shortflag; }
void setFlagInfo(char shortflag, const char* longflag, const char* help) {
this->shortflag = shortflag;
this->longflag = longflag;
this->help = help;
ValuedOption* asValued();
const ValuedOption* asValued() const;
#define OPTION_CONVERT_DECL(__cls) \
bool is##__cls##Option() const; \
__cls##Option* as##__cls##Option(); \
const __cls##Option* as##__cls##Option() const;
inline Option::~Option() {}
struct BoolOption : public Option {
size_t argno;
bool value;
BoolOption(char shortflag, const char* longflag, const char* help)
: Option(OptionKindBool, shortflag, longflag, help), value(false) {}
virtual ~BoolOption() {}
struct ValuedOption : public Option {
const char* metavar;
ValuedOption(OptionKind kind, char shortflag, const char* longflag,
const char* help, const char* metavar)
: Option(kind, shortflag, longflag, help), metavar(metavar) {}
virtual ~ValuedOption() = 0;
virtual bool isValued() const override { return true; }
inline ValuedOption::~ValuedOption() {}
struct StringOption : public ValuedOption {
const char* value;
StringOption(char shortflag, const char* longflag, const char* help,
const char* metavar)
: ValuedOption(OptionKindString, shortflag, longflag, help, metavar),
value(nullptr) {}
virtual ~StringOption() {}
struct IntOption : public ValuedOption {
int value;
IntOption(char shortflag, const char* longflag, const char* help,
const char* metavar, int defaultValue)
: ValuedOption(OptionKindInt, shortflag, longflag, help, metavar),
value(defaultValue) {}
virtual ~IntOption() {}
struct StringArg {
char* value;
size_t argno;
StringArg(char* value, size_t argno) : value(value), argno(argno) {}
struct MultiStringOption : public ValuedOption {
Vector<StringArg, 0, detail::OptionAllocPolicy> strings;
MultiStringOption(char shortflag, const char* longflag, const char* help,
const char* metavar)
: ValuedOption(OptionKindMultiString, shortflag, longflag, help,
metavar) {}
virtual ~MultiStringOption() {}
virtual bool isVariadic() const override { return true; }
} /* namespace detail */
class MultiStringRange {
typedef detail::StringArg StringArg;
const StringArg* cur;
const StringArg* end;
explicit MultiStringRange(const StringArg* cur, const StringArg* end)
: cur(cur), end(end) {
MOZ_ASSERT(end - cur >= 0);
bool empty() const { return cur == end; }
void popFront() {
char* front() const {
return cur->value;
size_t argno() const {
return cur->argno;
* Builder for describing a command line interface and parsing the resulting
* specification.
* - A multi-option is an option that can appear multiple times and still
* parse as valid command line arguments.
* - An "optional argument" is supported for backwards compatibility with prior
* command line interface usage. Once one optional argument has been added,
* *only* optional arguments may be added.
class OptionParser {
enum Result {
Okay = 0,
Fail, /* As in, allocation fail. */
ParseError, /* Successfully parsed but with an error. */
EarlyExit /* Successfully parsed but exits the program,
* for example with --help and --version. */
typedef Vector<detail::Option*, 0, detail::OptionAllocPolicy> Options;
typedef detail::Option Option;
typedef detail::BoolOption BoolOption;
Options options;
Options arguments;
BoolOption helpOption;
BoolOption versionOption;
const char* usage;
const char* version;
const char* descr;
size_t descrWidth;
size_t helpWidth;
size_t nextArgument;
// If '--' is passed, all remaining arguments should be interpreted as the
// argument at index 'restArgument'. Defaults to the next unassigned
// argument.
int restArgument;
Option* findOption(char shortflag);
const Option* findOption(char shortflag) const;
const Option* tryFindOption(char shortflag) const;
Option* findOption(const char* longflag);
const Option* findOption(const char* longflag) const;
const Option* tryFindOption(const char* longflag) const;
int findArgumentIndex(const char* name) const;
Option* findArgument(const char* name);
const Option* findArgument(const char* name) const;
Result error(const char* fmt, ...) MOZ_FORMAT_PRINTF(2, 3);
Result extractValue(size_t argc, char** argv, size_t* i, char** value);
Result handleArg(size_t argc, char** argv, size_t* i, bool* optsAllowed);
Result handleOption(Option* opt, size_t argc, char** argv, size_t* i,
bool* optsAllowed);
explicit OptionParser(const char* usage)
: helpOption('h', "help", "Display help information"),
versionOption('v', "version", "Display version information and exit"),
restArgument(-1) {}
Result parseArgs(int argc, char** argv);
Result printHelp(const char* progname);
Result printVersion();
/* Metadata */
void setVersion(const char* v) { version = v; }
void setHelpWidth(size_t width) { helpWidth = width; }
void setDescriptionWidth(size_t width) { descrWidth = width; }
void setDescription(const char* description) { descr = description; }
void setHelpOption(char shortflag, const char* longflag, const char* help);
void setArgTerminatesOptions(const char* name, bool enabled);
void setArgCapturesRest(const char* name);
/* Arguments: no further arguments may be added after a variadic argument. */
bool addOptionalStringArg(const char* name, const char* help);
bool addOptionalMultiStringArg(const char* name, const char* help);
const char* getStringArg(const char* name) const;
MultiStringRange getMultiStringArg(const char* name) const;
/* Options */
bool addBoolOption(char shortflag, const char* longflag, const char* help);
bool addStringOption(char shortflag, const char* longflag, const char* help,
const char* metavar);
bool addIntOption(char shortflag, const char* longflag, const char* help,
const char* metavar, int defaultValue);
bool addMultiStringOption(char shortflag, const char* longflag,
const char* help, const char* metavar);
bool addOptionalVariadicArg(const char* name);
int getIntOption(char shortflag) const;
int getIntOption(const char* longflag) const;
const char* getStringOption(char shortflag) const;
const char* getStringOption(const char* longflag) const;
bool getBoolOption(char shortflag) const;
bool getBoolOption(const char* longflag) const;
MultiStringRange getMultiStringOption(char shortflag) const;
MultiStringRange getMultiStringOption(const char* longflag) const;
* Return whether the help option was present (and thus help was already
* displayed during parse_args).
bool getHelpOption() const;
} /* namespace cli */
} /* namespace js */
#endif /* shell_jsoptparse_h */