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/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SK_COMMAND_LINE_FLAGS_H
#define SK_COMMAND_LINE_FLAGS_H
#include "include/core/SkString.h"
#include "include/private/SkTArray.h"
#include "include/private/SkTDArray.h"
/**
* Including this file (and compiling CommandLineFlags.cpp) provides command line
* parsing. In order to use it, use the following macros in global
* namespace:
*
* DEFINE_bool(name, defaultValue, helpString);
* DEFINE_string(name, defaultValue, helpString);
* DEFINE_int(name, defaultValue, helpString);
* DEFINE_double(name, defaultValue, helpString);
*
* Then, in main, call CommandLineFlags::SetUsage() to describe usage and call
* CommandLineFlags::Parse() to parse the flags. Henceforth, each flag can
* be referenced using
*
* FLAGS_name
*
* For example, the line
*
* DEFINE_bool(boolean, false, "The variable boolean does such and such");
*
* will create the following variable:
*
* bool FLAGS_boolean;
*
* which will initially be set to false, and can be set to true by using the
* flag "--boolean" on the commandline. "--noboolean" will set FLAGS_boolean
* to false. FLAGS_boolean can also be set using "--boolean=true" or
* "--boolean true" (where "true" can be replaced by "false", "TRUE", "FALSE",
* "1" or "0").
*
* The helpString will be printed if the help flag (-h or -help) is used.
*
* Similarly, the line
*
* DEFINE_int(integer, .., ..);
*
* will create
*
* int FLAGS_integer;
*
* and
*
* DEFINE_double(real, .., ..);
*
* will create
*
* double FLAGS_real;
*
* These flags can be set by specifying, for example, "--integer 7" and
* "--real 3.14" on the command line. Unsigned integers are parsed from the
* command line using strtoul() so will detect the base (0 for octal, and
* 0x or 0X for hex, otherwise assumes decimal).
*
* Unlike the others, the line
*
* DEFINE_string(args, .., ..);
*
* creates an array:
*
* CommandLineFlags::StringArray FLAGS_args;
*
* If the default value is the empty string, FLAGS_args will default to a size
* of zero. Otherwise it will default to a size of 1 with the default string
* as its value. All strings that follow the flag on the command line (until
* a string that begins with '-') will be entries in the array.
*
* DEFINE_extended_string(args, .., .., extendedHelpString);
*
* creates a similar string array flag as DEFINE_string. The flag will have extended help text
* (extendedHelpString) that can the user can see with '--help <args>' flag.
*
* Any flag can be referenced from another file after using the following:
*
* DECLARE_x(name);
*
* (where 'x' is the type specified in the DEFINE).
*
* Inspired by gflags (https://code.google.com/p/gflags/). Is not quite as
* robust as gflags, but suits our purposes. For example, allows creating
* a flag -h or -help which will never be used, since CommandLineFlags handles it.
* CommandLineFlags will also allow creating --flag and --noflag. Uses the same input
* format as gflags and creates similarly named variables (i.e. FLAGS_name).
* Strings are handled differently (resulting variable will be an array of
* strings) so that a flag can be followed by multiple parameters.
*/
class SkFlagInfo;
class CommandLineFlags {
public:
/**
* Call to set the help message to be displayed. Should be called before
* Parse.
*/
static void SetUsage(const char* usage);
/**
* Call this to display the help message. Should be called after SetUsage.
*/
static void PrintUsage();
/**
* Call at the beginning of main to parse flags created by DEFINE_x, above.
* Must only be called once.
*/
static void Parse(int argc, const char* const* argv);
/**
* Custom class for holding the arguments for a string flag.
* Publicly only has accessors so the strings cannot be modified.
*/
class StringArray {
public:
StringArray() {}
explicit StringArray(const SkTArray<SkString>& strings) : fStrings(strings) {}
const char* operator[](int i) const {
SkASSERT(i >= 0 && i < fStrings.count());
return fStrings[i].c_str();
}
int count() const { return fStrings.count(); }
bool isEmpty() const { return this->count() == 0; }
/**
* Returns true iff string is equal to one of the strings in this array.
*/
bool contains(const char* string) const {
for (int i = 0; i < fStrings.count(); i++) {
if (fStrings[i].equals(string)) {
return true;
}
}
return false;
}
void set(int i, const char* str) {
if (i >= fStrings.count()) {
this->append(str);
return;
}
fStrings[i].set(str);
}
const SkString* begin() const { return fStrings.begin(); }
const SkString* end() const { return fStrings.end(); }
private:
void reset() { fStrings.reset(); }
void append(const char* string) { fStrings.push_back().set(string); }
void append(const char* string, size_t length) { fStrings.push_back().set(string, length); }
SkTArray<SkString> fStrings;
friend class SkFlagInfo;
};
/* Takes a list of the form [~][^]match[$]
~ causes a matching test to always be skipped
^ requires the start of the test to match
$ requires the end of the test to match
^ and $ requires an exact match
If a test does not match any list entry, it is skipped unless some list entry starts with ~
*/
static bool ShouldSkip(const SkTDArray<const char*>& strings, const char* name);
static bool ShouldSkip(const StringArray& strings, const char* name);
private:
static SkFlagInfo* gHead;
static SkString gUsage;
// For access to gHead.
friend class SkFlagInfo;
};
#define TO_STRING2(s) #s
#define TO_STRING(s) TO_STRING2(s)
#define DEFINE_bool(name, defaultValue, helpString) \
bool FLAGS_##name; \
SK_UNUSED static bool unused_##name = SkFlagInfo::CreateBoolFlag( \
TO_STRING(name), nullptr, &FLAGS_##name, defaultValue, helpString)
// bool 2 allows specifying a short name. No check is done to ensure that shortName
// is actually shorter than name.
#define DEFINE_bool2(name, shortName, defaultValue, helpString) \
bool FLAGS_##name; \
SK_UNUSED static bool unused_##name = SkFlagInfo::CreateBoolFlag( \
TO_STRING(name), TO_STRING(shortName), &FLAGS_##name, defaultValue, helpString)
#define DECLARE_bool(name) extern bool FLAGS_##name;
#define DEFINE_string(name, defaultValue, helpString) \
CommandLineFlags::StringArray FLAGS_##name; \
SK_UNUSED static bool unused_##name = SkFlagInfo::CreateStringFlag( \
TO_STRING(name), nullptr, &FLAGS_##name, defaultValue, helpString, nullptr)
#define DEFINE_extended_string(name, defaultValue, helpString, extendedHelpString) \
CommandLineFlags::StringArray FLAGS_##name; \
SK_UNUSED static bool unused_##name = SkFlagInfo::CreateStringFlag( \
TO_STRING(name), nullptr, &FLAGS_##name, defaultValue, helpString, extendedHelpString)
// string2 allows specifying a short name. There is an assert that shortName
// is only 1 character.
#define DEFINE_string2(name, shortName, defaultValue, helpString) \
CommandLineFlags::StringArray FLAGS_##name; \
SK_UNUSED static bool unused_##name = SkFlagInfo::CreateStringFlag(TO_STRING(name), \
TO_STRING(shortName), \
&FLAGS_##name, \
defaultValue, \
helpString, \
nullptr)
#define DECLARE_string(name) extern CommandLineFlags::StringArray FLAGS_##name;
#define DEFINE_int(name, defaultValue, helpString) \
int FLAGS_##name; \
SK_UNUSED static bool unused_##name = \
SkFlagInfo::CreateIntFlag(TO_STRING(name), &FLAGS_##name, defaultValue, helpString)
#define DEFINE_int_2(name, shortName, defaultValue, helpString) \
int FLAGS_##name; \
SK_UNUSED static bool unused_##name = SkFlagInfo::CreateIntFlag( \
TO_STRING(name), TO_STRING(shortName), &FLAGS_##name, defaultValue, helpString)
#define DECLARE_int(name) extern int FLAGS_##name;
#define DEFINE_double(name, defaultValue, helpString) \
double FLAGS_##name; \
SK_UNUSED static bool unused_##name = \
SkFlagInfo::CreateDoubleFlag(TO_STRING(name), &FLAGS_##name, defaultValue, helpString)
#define DECLARE_double(name) extern double FLAGS_##name;
class SkFlagInfo {
public:
enum FlagTypes {
kBool_FlagType,
kString_FlagType,
kInt_FlagType,
kDouble_FlagType,
};
/**
* Each Create<Type>Flag function creates an SkFlagInfo of the specified type. The SkFlagInfo
* object is appended to a list, which is deleted when CommandLineFlags::Parse is called.
* Therefore, each call should be made before the call to ::Parse. They are not intended
* to be called directly. Instead, use the macros described above.
* @param name Long version (at least 2 characters) of the name of the flag. This name can
* be referenced on the command line as "--name" to set the value of this flag.
* @param shortName Short version (one character) of the name of the flag. This name can
* be referenced on the command line as "-shortName" to set the value of this flag.
* @param p<Type> Pointer to a global variable which holds the value set by CommandLineFlags.
* @param defaultValue The default value of this flag. The variable pointed to by p<Type> will
* be set to this value initially. This is also displayed as part of the help output.
* @param helpString Explanation of what this flag changes in the program.
*/
static bool CreateBoolFlag(const char* name,
const char* shortName,
bool* pBool,
bool defaultValue,
const char* helpString) {
SkFlagInfo* info = new SkFlagInfo(name, shortName, kBool_FlagType, helpString, nullptr);
info->fBoolValue = pBool;
*info->fBoolValue = info->fDefaultBool = defaultValue;
return true;
}
/**
* See comments for CreateBoolFlag.
* @param pStrings Unlike the others, this is a pointer to an array of values.
* @param defaultValue Thise default will be parsed so that strings separated by spaces
* will be added to pStrings.
*/
static bool CreateStringFlag(const char* name,
const char* shortName,
CommandLineFlags::StringArray* pStrings,
const char* defaultValue,
const char* helpString,
const char* extendedHelpString);
/**
* See comments for CreateBoolFlag.
*/
static bool CreateIntFlag(const char* name,
int* pInt,
int defaultValue,
const char* helpString) {
SkFlagInfo* info = new SkFlagInfo(name, nullptr, kInt_FlagType, helpString, nullptr);
info->fIntValue = pInt;
*info->fIntValue = info->fDefaultInt = defaultValue;
return true;
}
static bool CreateIntFlag(const char* name,
const char* shortName,
int* pInt,
int defaultValue,
const char* helpString) {
SkFlagInfo* info = new SkFlagInfo(name, shortName, kInt_FlagType, helpString, nullptr);
info->fIntValue = pInt;
*info->fIntValue = info->fDefaultInt = defaultValue;
return true;
}
/**
* See comments for CreateBoolFlag.
*/
static bool CreateDoubleFlag(const char* name,
double* pDouble,
double defaultValue,
const char* helpString) {
SkFlagInfo* info = new SkFlagInfo(name, nullptr, kDouble_FlagType, helpString, nullptr);
info->fDoubleValue = pDouble;
*info->fDoubleValue = info->fDefaultDouble = defaultValue;
return true;
}
/**
* Returns true if the string matches this flag.
* For a boolean flag, also sets the value, since a boolean flag can be set in a number of ways
* without looking at the following string:
* --name
* --noname
* --name=true
* --name=false
* --name=1
* --name=0
* --name=TRUE
* --name=FALSE
*/
bool match(const char* string);
FlagTypes getFlagType() const { return fFlagType; }
void resetStrings() {
if (kString_FlagType == fFlagType) {
fStrings->reset();
} else {
SkDEBUGFAIL("Can only call resetStrings on kString_FlagType");
}
}
void append(const char* string) {
if (kString_FlagType == fFlagType) {
fStrings->append(string);
} else {
SkDEBUGFAIL("Can only append to kString_FlagType");
}
}
void setInt(int value) {
if (kInt_FlagType == fFlagType) {
*fIntValue = value;
} else {
SkDEBUGFAIL("Can only call setInt on kInt_FlagType");
}
}
void setDouble(double value) {
if (kDouble_FlagType == fFlagType) {
*fDoubleValue = value;
} else {
SkDEBUGFAIL("Can only call setDouble on kDouble_FlagType");
}
}
void setBool(bool value) {
if (kBool_FlagType == fFlagType) {
*fBoolValue = value;
} else {
SkDEBUGFAIL("Can only call setBool on kBool_FlagType");
}
}
SkFlagInfo* next() { return fNext; }
const SkString& name() const { return fName; }
const SkString& shortName() const { return fShortName; }
const SkString& help() const { return fHelpString; }
const SkString& extendedHelp() const { return fExtendedHelpString; }
SkString defaultValue() const {
SkString result;
switch (fFlagType) {
case SkFlagInfo::kBool_FlagType:
result.printf("%s", fDefaultBool ? "true" : "false");
break;
case SkFlagInfo::kString_FlagType: return fDefaultString;
case SkFlagInfo::kInt_FlagType: result.printf("%i", fDefaultInt); break;
case SkFlagInfo::kDouble_FlagType: result.printf("%2.2f", fDefaultDouble); break;
default: SkDEBUGFAIL("Invalid flag type");
}
return result;
}
SkString typeAsString() const {
switch (fFlagType) {
case SkFlagInfo::kBool_FlagType: return SkString("bool");
case SkFlagInfo::kString_FlagType: return SkString("string");
case SkFlagInfo::kInt_FlagType: return SkString("int");
case SkFlagInfo::kDouble_FlagType: return SkString("double");
default: SkDEBUGFAIL("Invalid flag type"); return SkString();
}
}
private:
SkFlagInfo(const char* name,
const char* shortName,
FlagTypes type,
const char* helpString,
const char* extendedHelpString)
: fName(name)
, fShortName(shortName)
, fFlagType(type)
, fHelpString(helpString)
, fExtendedHelpString(extendedHelpString)
, fBoolValue(nullptr)
, fDefaultBool(false)
, fIntValue(nullptr)
, fDefaultInt(0)
, fDoubleValue(nullptr)
, fDefaultDouble(0)
, fStrings(nullptr) {
fNext = CommandLineFlags::gHead;
CommandLineFlags::gHead = this;
SkASSERT(name && strlen(name) > 1);
SkASSERT(nullptr == shortName || 1 == strlen(shortName));
}
/**
* Set a StringArray to hold the values stored in defaultStrings.
* @param array The StringArray to modify.
* @param defaultStrings Space separated list of strings that should be inserted into array
* individually.
*/
static void SetDefaultStrings(CommandLineFlags::StringArray* array, const char* defaultStrings);
// Name of the flag, without initial dashes
SkString fName;
SkString fShortName;
FlagTypes fFlagType;
SkString fHelpString;
SkString fExtendedHelpString;
bool* fBoolValue;
bool fDefaultBool;
int* fIntValue;
int fDefaultInt;
double* fDoubleValue;
double fDefaultDouble;
CommandLineFlags::StringArray* fStrings;
// Both for the help string and in case fStrings is empty.
SkString fDefaultString;
// In order to keep a linked list.
SkFlagInfo* fNext;
};
#endif // SK_COMMAND_LINE_FLAGS_H