1. A computer program product for compiler support, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a computer to cause the computer to perform a method comprising: implementing a function, which a compiler for a first language does not have, using a compiler for a second language, wherein said implementing step includes: generating, by the compiler for the first language, a first abstract syntax tree by parsing source code written in the first language or a domain specific language based on the first language; converting, by a data representation type converter, the first abstract syntax tree to a second abstract syntax tree of the compiler for the second language using a conversion table from data representation types in the first language to data representation types in the second language; when a compilation error occurs in the compiler for the second language, generating therein a special node for error processing in the second abstract syntax tree and storing an error token indicating information of the compilation error in the special node; and when unparsing by the compiler for the second language, outputting the error token stored in the special node, in the form of source code written in the first language.