typeinfo.cpp

/***************************************************************************
 *                                                                         *
 *   Copyright (C) 2017 Christian Schoenebeck                              *
 *                      <cuse@users.sourceforge.net>                       *
 *                                                                         *
 *   This library is part of libgig.                                       *
 *                                                                         *
 *   This library is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This library is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this library; if not, write to the Free Software           *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/
 
#include <typeinfo>
#include <map>
#include <string>
#include <stdlib.h>
#include <stdint.h>
#include <string.h> // for strdup()
 
#if defined _MSC_VER // Microsoft compiler ...
# define RAW_CPP_TYPENAME(t) t.raw_name()
#else // i.e. especially GCC and clang ...
# define RAW_CPP_TYPENAME(t) t.name()
#endif
 
#define RAW_CPP_TYPENAME_OF(type) RAW_CPP_TYPENAME(typeid(type))
 
#define GIG_DECLARE_ENUM(type, ...) \
    enum type { __VA_ARGS__ }; \
    \
    struct type##InfoRegistrator { \
        type##InfoRegistrator() { \
            const char* typeName = RAW_CPP_TYPENAME_OF(type); \
            g_enumsByRawTypeName[typeName] = _parseEnumBody( #__VA_ARGS__ ); \
        } \
    }; \
    \
    static type##InfoRegistrator g_##type##InfoRegistrator
 
struct EnumDeclaration {
    std::map<size_t, std::string> nameByValue;
    std::map<std::string, size_t> valueByName;
    char** allKeys;
 
    EnumDeclaration() : allKeys(NULL) {}
 
    const size_t countKeys() const { return valueByName.size(); }
 
    void loadAllKeys() {
        const size_t n = valueByName.size();
        allKeys = new char*[n + 1];
        size_t i = 0;
        for (std::map<std::string, size_t>::const_iterator it = valueByName.begin();
             it != valueByName.end(); ++it, ++i)
        {
            allKeys[i] = strdup(it->first.c_str());
        }
        allKeys[n] = NULL;
    }
};
 
struct EnumKeyVal {
    std::string name;
    size_t value;
    bool isValid() const { return !name.empty(); }
};
 
static std::map<std::string, EnumDeclaration> g_enumsByRawTypeName;
static std::map<std::string, size_t> g_allEnumValuesByKey;
 
 
 
// *************** Internal functions **************
// *
 
static inline bool isWhiteSpace(const char& c) {
    return c == ' ' || c == '\t' || c == '\n' || c == '\r';
}
 
static size_t decodeEnumValue(const std::string& encodedValue) {
    return strtoll(encodedValue.c_str(), NULL, 0 /* auto detect base */);
}
 
static EnumKeyVal _parseEnumKeyVal(const char* start, const char* end, size_t value) {
    EnumKeyVal keyval;
 
    if (start >= end)
        return keyval; // invalid
    // ignore white space
    for (; isWhiteSpace(*start); ++start)
        if (start >= end)
            return keyval; // invalid
    if (start >= end)
        return keyval; // invalid
 
    // parse key
    for (const char* p = start; true; ++p) {
        if (p >= end || isWhiteSpace(*p) || *p == '=') {
            const size_t sz = p - start;
            keyval.name.resize(sz);
            memcpy(&keyval.name[0], start, sz);
            keyval.value = value;
            start = p + 1;
            break;
        }
    }
 
    if (start >= end)
        return keyval; // valid, no explicit value provided
    // seek forward to start of value
    for (; isWhiteSpace(*start) || *start == '='; ++start)
        if (start >= end)
            return keyval; // valid, no explicit value provided
    if (start >= end)
        return keyval; // valid, no explicit value provided
 
    std::string encodedValue;
    // parse value portion
    for (const char* p = start; true; ++p) {
        if (p >= end || isWhiteSpace(*p)) {
            const size_t sz = p - start;
            encodedValue.resize(sz);
            memcpy(&encodedValue[0], start, sz);
            break;
        }
    }
 
    if (encodedValue.empty())
        return keyval; // valid, no explicit value provided
 
    keyval.value = decodeEnumValue(encodedValue);
 
    return keyval;
}
 
static EnumDeclaration _parseEnumBody(const char* body) {
    EnumDeclaration decl;
    size_t value = 0;
    for (const char* a = body, *b = body; true; ++b) {
        if (*b == 0 || *b == ',') {
            const EnumKeyVal keyval = _parseEnumKeyVal(a, b, value);
            if (!keyval.isValid()) break;
            decl.nameByValue[keyval.value] = keyval.name;
            decl.valueByName[keyval.name] = keyval.value;
            g_allEnumValuesByKey[keyval.name] = keyval.value;
            value = keyval.value + 1;
            if (*b == 0) break;
            a = b + 1;
        }
    }
    return decl;
}
 
#include "gig.h"
 
// *************** gig API functions **************
// *
 
namespace gig {
 
    // this has to be defined manually, since leverarge_ctrl_t::type_t is a
    // class internal member type
    static leverage_ctrl_t::type_tInfoRegistrator g_leverageCtrlTTypeT;
 
 
    size_t enumCount(String typeName) {
        if (!g_enumsByRawTypeName.count(typeName))
            return 0;
        return g_enumsByRawTypeName[typeName].countKeys();
    }
 
    size_t enumCount(const std::type_info& type) {
        return enumCount(RAW_CPP_TYPENAME(type));
    }
 
    size_t enumValue(String key) {
        if (!g_allEnumValuesByKey.count(key))
            return 0;
        return g_allEnumValuesByKey[key];
    }
 
    bool enumKey(String typeName, String key) {
        if (!g_enumsByRawTypeName.count(typeName))
            return false;
        return g_enumsByRawTypeName[typeName].valueByName.count(key);
    }
 
    bool enumKey(const std::type_info& type, String key) {
        return enumKey(RAW_CPP_TYPENAME(type), key);
    }
 
    const char* enumKey(String typeName, size_t value) {
        if (!g_enumsByRawTypeName.count(typeName))
            return NULL;
        if (!g_enumsByRawTypeName[typeName].nameByValue.count(value))
            return NULL;
        return g_enumsByRawTypeName[typeName].nameByValue[value].c_str();
    }
 
    const char* enumKey(const std::type_info& type, size_t value) {
        return enumKey(RAW_CPP_TYPENAME(type), value);
    }
 
    const char** enumKeys(String typeName) {
        if (!g_enumsByRawTypeName.count(typeName))
            return NULL;
        if (!g_enumsByRawTypeName[typeName].allKeys)
            g_enumsByRawTypeName[typeName].loadAllKeys();
        return (const char**) g_enumsByRawTypeName[typeName].allKeys;
    }
 
    const char** enumKeys(const std::type_info& type) {
        return enumKeys(RAW_CPP_TYPENAME(type));
    }
 
} // namespace gig