如何在clang插件中运行PostgreSQL连接代码

Question

我在clang插件中编写了PostgreSQL连接代码，如下所示。

class PrintFunctionNamesAction : public PluginASTAction {
protected:
    ASTConsumer *CreateASTConsumer(CompilerInstance &CI, llvm::StringRef) {
    PGconn          *conn;
    PGresult        *res;
    int             rec_count;
    int             row;
    int             col;


     conn = PQconnectdb("dbname=a host=localhost user=user password=user123");

     if (PQstatus(conn) == CONNECTION_BAD) {
             puts("We were unable to connect to the database");
             //break;
     }

     res = PQexec(conn,
             "update people set phonenumber=\'8983194618\' where id=3");

     res = PQexec(conn,
             "select lastname,firstname,phonenumber from people order by id");

     if (PQresultStatus(res) != PGRES_TUPLES_OK) {
            puts("We did not get any data!");
             //break;
     }

     rec_count = PQntuples(res);

     printf("We received %d records.\n", rec_count);
     puts("==========================");

     for (row=0; row<rec_count; row++) {
             for (col=0; col<3; col++) {
                     printf("%s\t", PQgetvalue(res, row, col));
             }
             puts("");
     }

     puts("==========================");

     PQclear(res);

     PQfinish(conn);
return new PrintFunctionsConsumer();
}

它没有给出任何编译时错误，但我得到以下错误是运行时。

clang++ -cc1 -load ../../../../Release+Asserts/lib/libPrintFunctionNames.so 
  -plugin print-fns -plugin-arg-print-fns -lpq test.cpp PrintFunctionNames 
   arg = -lpq clang++: symbol lookup error: ../../../../Release+Asserts
   /lib/libPrintFunctionNames.so: undefined symbol: PQconnectdb