/*
* 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 "SkString.h"
#include "SkTArray.h"
#include "SkTDArray.h"
/**
* Including this file (and compiling SkCommandLineFlags.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_int32(name, defaultValue, helpString);
* DEFINE_double(name, defaultValue, helpString);
*
* Then, in main, call SkCommandLineFlags::SetUsage() to describe usage and call
* SkCommandLineFlags::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_int32(integer, .., ..);
*
* will create
*
* int32_t 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.
*
* Unlike the others, the line
*
* DEFINE_string(args, .., ..);
*
* creates an array:
*
* SkCommandLineFlags::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.
*
* 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 SkCommandLineFlags handles it.
* SkCommandLineFlags 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 SkCommandLineFlags {
public:
/**
* Call to set the help message to be displayed. Should be called before
* Parse.
*/
static void SetUsage(const char* usage);
/**
* Call at the beginning of main to parse flags created by DEFINE_x, above.
* Must only be called once.
*/
static void Parse(int argc, char** argv);
/**
* Custom class for holding the arguments for a string flag.
* Publicly only has accessors so the strings cannot be modified.
*/
class StringArray {
public:
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;
}
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; \
static bool unused_##name = SkFlagInfo::CreateBoolFlag(TO_STRING(name), \
NULL, \
&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; \
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) \
SkCommandLineFlags::StringArray FLAGS_##name; \
static bool unused_##name = SkFlagInfo::CreateStringFlag(TO_STRING(name), \
NULL, \
&FLAGS_##name, \
defaultValue, \
helpString)
// string2 allows specifying a short name. There is an assert that shortName
// is only 1 character.
#define DEFINE_string2(name, shortName, defaultValue, helpString) \
SkCommandLineFlags::StringArray FLAGS_##name; \
static bool unused_##name = SkFlagInfo::CreateStringFlag(TO_STRING(name), \
TO_STRING(shortName), \
&FLAGS_##name, \
defaultValue, \
helpString)
#define DECLARE_string(name) extern SkCommandLineFlags::StringArray FLAGS_##name;
#define DEFINE_int32(name, defaultValue, helpString) \
int32_t FLAGS_##name; \
static bool unused_##name = SkFlagInfo::CreateIntFlag(TO_STRING(name), \
&FLAGS_##name, \
defaultValue, \
helpString)
#define DECLARE_int32(name) extern int32_t FLAGS_##name;
#define DEFINE_double(name, defaultValue, helpString) \
double FLAGS_##name; \
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 SkCommandLineFlags::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 SkCommandLineFlags.
* @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 = SkNEW_ARGS(SkFlagInfo, (name, shortName, kBool_FlagType, helpString));
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,
SkCommandLineFlags::StringArray* pStrings,
const char* defaultValue, const char* helpString);
/**
* See comments for CreateBoolFlag.
*/
static bool CreateIntFlag(const char* name, int32_t* pInt,
int32_t defaultValue, const char* helpString) {
SkFlagInfo* info = SkNEW_ARGS(SkFlagInfo, (name, NULL, kInt_FlagType, helpString));
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 = SkNEW_ARGS(SkFlagInfo, (name, NULL, kDouble_FlagType, helpString));
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(int32_t 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; }
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)
: fName(name)
, fShortName(shortName)
, fFlagType(type)
, fHelpString(helpString)
, fBoolValue(NULL)
, fDefaultBool(false)
, fIntValue(NULL)
, fDefaultInt(0)
, fDoubleValue(NULL)
, fDefaultDouble(0)
, fStrings(NULL) {
fNext = SkCommandLineFlags::gHead;
SkCommandLineFlags::gHead = this;
SkASSERT(NULL != name && strlen(name) > 1);
SkASSERT(NULL == 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(SkCommandLineFlags::StringArray* array,
const char* defaultStrings);
// Name of the flag, without initial dashes
SkString fName;
SkString fShortName;
FlagTypes fFlagType;
SkString fHelpString;
bool* fBoolValue;
bool fDefaultBool;
int32_t* fIntValue;
int32_t fDefaultInt;
double* fDoubleValue;
double fDefaultDouble;
SkCommandLineFlags::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