cdlmisc.cxx

移植到WLIT项目的redboot源代码

// ----------------------------------------------------------------------------
// Similar support for value sources.

static struct {
    char*               name;
    CdlValueSource      source;
} valid_sources[] = {
    { "default",        CdlValueSource_Default  },
    { "inferred",       CdlValueSource_Inferred },
    { "wizard",         CdlValueSource_Wizard   },
    { "user",           CdlValueSource_User     },
    { 0,                CdlValueSource_Invalid  }
};

bool
Cdl::string_to_source(std::string name, CdlValueSource& target)
{
    CYG_REPORT_FUNCNAMETYPE("Cdl::string_to_source", "success %d");

    bool result = false;

    // First convert the argument to lower case. Arguably this is incorrect,
    // Tcl is a case-sensitive language, but the conversion is unlikely ever
    // to be harmfull.
    for (std::string::iterator str_i = name.begin(); str_i != name.end(); str_i++) {
        if (isupper(*str_i)) {
            *str_i = tolower(*str_i);
        }
    }
           
    // Now look for a match in the table.
    int match           = -1;
    int i;
    const char* c_str   = name.c_str();
    int len             = strlen(c_str);

    for (i = 0; 0 != valid_sources[i].name; i++) {
        if (0 == strncmp(c_str, valid_sources[i].name, len)) {
            // Check for an ambiguous string match.
            // This cannot actually happen with the current source names.
            if ( -1 != match) {
                break;
            }
            match = i;
        }
        
    }
    if (-1 != match) {
        target = valid_sources[match].source;
        result = true;
    }
    CYG_REPORT_RETVAL(result);
    return result;
}

bool
Cdl::source_to_string(CdlValueSource source, std::string& target)
{
    CYG_REPORT_FUNCNAMETYPE("Cdl::source_to_string", "success %d");

    bool result = false;

    for (int i = 0; 0 != valid_sources[i].name; i++) {
        if (source == valid_sources[i].source) {
            target = valid_sources[i].name;
            result = true;
            break;
        }
    }
    
    CYG_REPORT_RETVAL(result);
    return result;
}

//}}}
//{{{  Cdl::get_library_version()                               

// ----------------------------------------------------------------------------
// The version of the library actually lives inside configure.in. It gets
// exported into cdlconfig.h
std::string
Cdl::get_library_version(void)
{
    return std::string(CYGNUM_LIBCDL_VERSION);
}

//}}}
//{{{  Cdl::set_interactive()                                   

// ----------------------------------------------------------------------------
// Some CDL scripts and some bits of the library may want to adapt depending
// on whether or not the application is running fully interactively or in
// batch mode. The primary distinction is that a batch program should never
// attempt to obtain user input, whether via Tk widgets or by other means.

bool Cdl::interactive   = false;

void
Cdl::set_interactive(bool value)
{
    CYG_REPORT_FUNCNAME("Cdl::set_interactive");
    CYG_REPORT_FUNCARG1D(value);

    interactive = value;
}

bool
Cdl::is_interactive(void)
{
    CYG_REPORT_FUNCNAMETYPE("Cdl::is_interactive", "interactive %d");
    CYG_REPORT_RETVAL(interactive);
    return interactive;
}

//}}}
//{{{  version support()                                        

// ----------------------------------------------------------------------------
// Packages may need to impose constraints on which versions of other
// packages they can coexist with. This requires some way of achieving
// a partial ordering of version numbers. Unfortunately there are many
// different ways of specifying a version number, and we cannot impose
// a single model on all third party package developers. Instead this
// routine performs some semi-intelligent comparisons of two version
// strings which should work in the vast majority of cases.
//
// The return value is as per strcmp(), -1 if the first entry is
// smaller (i.e. the more recent and hence hopefully the first in
// a list), +1 if the second entry is smaller, 0 if the two are
// identical.
//
// There is a big ambiguity between "derived" versions and "experimental"
// versions. Something like v0.3beta is experimental, i.e. it is older
// than the full release v0.3. On the other hand v0.3.p1 is a patched
// version of v0.3 and hence newer. This code uses the presence or otherwise
// of a separator to decide between the two cases.

// A utility routine which checks whether or not a character counts
// as a separator. Currently the characters . - and _ are all accepted
// as field separators.
//
// Arguably - should not be accepted as a separator. Instead if it preceeds
// a digit it could be interpreted as part of a prerelease number.

static bool
is_separator(int ch)
{
    return ('.' == ch) || ('-' == ch) || ('_' == ch);
}
    
int
Cdl::compare_versions(std::string arg1, std::string arg2)
{
    CYG_REPORT_FUNCNAMETYPE("Cdl::compare_versions", "result %d");

    if (arg1 == arg2) {
        CYG_REPORT_RETVAL(0);
        return 0;
    }

    // The version number "current" is special, it always indicates the most
    // recent version e.g. as checked out from a CVS repository.
    if ("current" == arg1) {
        CYG_REPORT_RETVAL(-1);
        return -1;
    }
    if ("current" == arg2) {
        CYG_REPORT_RETVAL(1);
        return 1;
    }

    const char* ptr1 = arg1.c_str();
    const char* ptr2 = arg2.c_str();      
    int num1    = 0;
    int num2    = 0;

    // If both strings start with 'v' or 'V', skip this. A minor variation in
    // case at the start of a string should be ignored.
    if ((('v' == *ptr1) || ('V' == *ptr1)) &&
        (('v' == *ptr2) || ('V' == *ptr2))) {
        ptr1++;
        ptr2++;
    }

    // Now process the rest of the version string, one unit at a time.
    while (1) {

        if (('\0' == *ptr1) && ('\0' == *ptr2)) {
            // Both strings have terminated at the same time. There
            // may have been some spurious leading zeroes in numbers,
            // or irrelevant differences in the separators.
            CYG_REPORT_RETVAL(0);
            return 0;
        }
        
        if ('\0' == *ptr1) {
            // The first string has ended first. If the second string currently
            // points at a separator then arg2 is a derived version, e.g.
            // v0.3.p1, and hence newer. Otherwise arg2 is an experimental
            // version v0.3beta and hence older.
            if (is_separator(*ptr2)) {
                CYG_REPORT_RETVAL(1);
                return 1;
            } else {
                CYG_REPORT_RETVAL(-1);
                return -1;
            }
        }

        if ('\0' == *ptr2) {
            // As per the previous test.
            if (is_separator(*ptr1)) {
                CYG_REPORT_RETVAL(-1);
                return -1;
            } else {
                CYG_REPORT_RETVAL(1);
                return 1;
            }
        }

        // If both strings currently point at numerical data, do a conversion and
        // a numerical comparison.
        if (isdigit(*ptr1) && isdigit(*ptr2)) {
            num1 = 0;
            num2 = 0;
            // Strictly speaking there should be some overflow tests here, but it
            // is not worth the trouble.
            do {
                num1 = (10 * num1) + (*ptr1++ - '0');
            } while(isdigit(*ptr1));
            do {
                num2 = (10 * num2) + (*ptr2++ - '0');
            } while(isdigit(*ptr2));
            // v2.0 is newer than v1.0
            if (num1 < num2) {
                CYG_REPORT_RETVAL(1);
                return 1;
            } else if (num1 > num2) {
                CYG_REPORT_RETVAL(-1);
                return -1;
            } else {
                continue;
            }
        }

        // Non-numerical data. If the two characters are the same then
        // move on. Note: this has to happen after numerical conversions
        // to distinguish v10.0 and v1.0
        if (*ptr1 == *ptr2) {
            ptr1++; ptr2++;
            continue;
        }

        // If both strings are currently at a separator then move on. All
        // separators can be used interchangeably.
        if (is_separator(*ptr1) && is_separator(*ptr2)) {
            ptr1++; ptr2++;
            continue;
        }

        // If only one string is at a separator, special action
        // is needed. v1.1alpha is interpreted as earlier than
        // v1.1, but v1.1.3 is a later release.
        if (is_separator(*ptr1)) {
            return -1;
        } else if (is_separator(*ptr2)) {
            return 1;
        }
        
        // Two different characters, e.g. v1.0alpha vs. v1.0beta
        if (*ptr1 < *ptr2) {
            CYG_REPORT_RETVAL(1);
            return 1;
        } else {
            CYG_REPORT_RETVAL(-1);
            return -1;
        }
    }

    // Not reachable.
}

// ----------------------------------------------------------------------------
// Given a version string, extract major, minor and release numbers.
// Some or all of these may be absent. Basically the code just
// iterates through the string looking for sequences of numbers.

static void
version_extract_number(const std::string& version, unsigned int& index, std::string& result)
{
    CYG_REPORT_FUNCNAME("version_extract_number");

    // The calling code is expected to supply a sensible default.
    // Search for a digit
    for ( ; index < version.size(); index++) {
        if (isdigit(version[index])) {
            break;
        }
    }
    if (index != version.size()) {
        result = "";
        if ((index > 0) && ('-' == version[index-1])) {
            result = "-";
        }
        do {
            result += version[index++];
        } while ((index < version.size()) && isdigit(version[index]));
    }
    
    CYG_REPORT_RETURN();
}

void
Cdl::split_version_string(const std::string& version, std::string& major, std::string& minor, std::string& release)
{
    CYG_REPORT_FUNCNAME("CdlMisc::split_version_string");

    unsigned int index = 0;
    version_extract_number(version, index, major);
    version_extract_number(version, index, minor);
    version_extract_number(version, index, release);
    
    CYG_REPORT_RETURN();
}

//}}}
//{{{  Cdl::get_short_form()                                    

// ----------------------------------------------------------------------------
// It is occasionally useful to take a full CDL name such as CYgpkg_KERNEL
// and turn it into a short form such as "kernel". This involves discarding
// everything up to and including the first underscore, then lowercasing
// all subsequent characters.
std::string
Cdl::get_short_form(const std::string& original)
{
    CYG_REPORT_FUNCNAME("CdlMisc::get_short_form");

    std::string  result = "";
    unsigned int size = original.size();
    unsigned int i;
    for (i = 0; i < size; i++) {
        if ('_' == original[i]) {
            i++;
            break;
        }
    }

    // Either at end of string, or just past the first underscore
    for ( ; i < size; i++) {
        if (isupper(original[i])) {
            result += tolower(original[i]);
        } else {
            result += original[i];
        }
    }
    
    CYG_REPORT_RETURN();
    return result;
}

//}}}