Réécriture de SystemTools::FileIsFullPath

is_full_path.cmake

########## Private ##########

# From Source/cmInstallGenerator.cxx:
# std::string cmInstallGenerator::GetInstallDestination() const
# {
#     std::string result;
# 
#     if(!this->Destination.empty() && !cmSystemTools::FileIsFullPath(this->Destination.c_str())) {
#         result = "${CMAKE_INSTALL_PREFIX}/";
#     }
#     result += this->Destination;
#     return result;
# }

# From Source/kwsys/SystemTools.cxx:
# bool SystemTools::FileIsFullPath(const char* in_name)
# {
#     kwsys_stl::string name = in_name;
# #if defined(_WIN32) || defined(__CYGWIN__)
#     // On Windows, the name must be at least two characters long.
#     if(name.length() < 2) {
#         return false;
#     }
#     if(name[1] == ':') {
#         return true;
#     }
#     if(name[0] == '\\') {
#         return true;
#     }
# #else
#     // On UNIX, the name must be at least one character long.
#     if(name.length() < 1) {
#         return false;
#     }
# #endif
# #if !defined(_WIN32)
#     if(name[0] == '~') {
#         return true;
#     }
# #endif
#     // On UNIX, the name must begin in a '/'.
#     // On Windows, if the name begins in a '/', then it is a full
#     // network path.
#     if(name[0] == '/') {
#         return true;
#     }
#     return false;
# }

function(is_full_path _path _outvar)
    string(LENGTH ${_path} PATH_LEN)
    string(SUBSTRING ${_path} 0 1 FIRST_CHAR)
    string(SUBSTRING ${_path} 1 1 SECOND_CHAR)

    if(WIN32 OR CYGWIN)
        if(PATH_LEN LESS 2)
            set(${_outvar} FALSE PARENT_SCOPE)
            return()
        endif(PATH_LEN LESS 2)
        if(SECOND_CHAR STREQUAL ":")
            set(${_outvar} TRUE PARENT_SCOPE)
            return()
        endif(FIRST_CHAR STREQUAL ":")
        if(FIRST_CHAR STREQUAL "\\")
            set(${_outvar} TRUE PARENT_SCOPE)
            return()
        endif(FIRST_CHAR STREQUAL "\\")
    else(WIN32 OR CYGWIN)
        if(PATH_LEN LESS 1)
            set(${_outvar} FALSE PARENT_SCOPE)
            return()
        endif(PATH_LEN LESS 1)
    endif(WIN32 OR CYGWIN)
    if(NOT WIN32)
        if(FIRST_CHAR STREQUAL "~")
            set(${_outvar} TRUE PARENT_SCOPE)
            return()
        endif(FIRST_CHAR STREQUAL "~")
    endif(NOT WIN32)
    if(FIRST_CHAR STREQUAL "/")
        set(${_outvar} TRUE PARENT_SCOPE)
        return()
    endif(FIRST_CHAR STREQUAL "/")
    set(${_outvar} FALSE PARENT_SCOPE)
endfunction(is_full_path)