Hello, I built a new gcc front end I would like to use the -fopenmp options when compiling my source file I could use the C front end options like -S -fdump-tree-all -O*, .... but when I use -fopenmp I get this error: uml1: warning: command line option â-fopenmpâ is valid for C/C++/Fortran/ObjC/ObjC++ but not for [enabled by default] this is my lang-specs.h: {".uml", "@uml", 0, 1, 0}, {"@uml", "uml1 %i %(invoke_as)", 0, 1, 0}, {"@uml", "uml1 %i %(cc1_options) %{!fsyntax-only:%(invoke_as)}", 0, 1, 0}, I added the fopenmp option to my lang.opt file as fortran fe does (as suggested in ...........) but I always get the same warning expect that my fe language name is added to the list of fe that enable the use of fopenmp uml1: warning: command line option â-fopenmpâ is valid for C/C++/Fortran/ObjC/ObjC++/uml but not for [enabled by default] there is also an error in my front end comes from the compiler implementation itself. In my new front end, I tried to build the Generic form correspending to #pragma omp parallel I get the gimplified expression as provided by c++ front end here is my gimple main () gimple_bind < <unnamed-signed:32> D.28; struct MyClass x; gimple_omp_parallel < BODY < gimple_bind < gimple_call <MyOperation1, NULL, &x> gimple_call <MyOperation2, NULL, &x> > > CLAUSES < shared(x) >, NULL, NULL > gimple_assign <integer_cst, D.28, 0, NULL> gimple_return <D.28> > MyOperation2 (struct MyClass * this) gimple_bind < gimple_assign <integer_cst, this->MyAttribute2, 15, NULL> gimple_return <NULL> > MyOperation1 (struct MyClass * this) gimple_bind < gimple_assign <integer_cst, this->MyAttribute1, 10, NULL> gimple_return <NULL> > but it does not contain the built-in function (as gimple generated from c++ fe) <built-in> (struct .omp_data_s.0 * .omp_data_i) { struct MyClass c [value-expr: *.omp_data_i->c]; struct MyClass * D.1788; struct MyClass * D.1787; struct MyClass * D.1786; struct MyClass * D.1785; <bb 5>: <bb 3>: gimple_assign <component_ref, D.1785, .omp_data_i->c, NULL> .... } one of the reason is that my flag_openmp is always null, even if I specify -fopenmp while compiling. i,e: when my front end calls the execute_lower_omp(void) it does nothing execute_lower_omp (void) { gimple_seq body; /* This pass always runs, to provide PROP_gimple_lomp. But there is nothing to do unless -fopenmp is given. */ if (flag_openmp == 0) return 0; .... } any idea to change fe flag_openmp value ? thank you very much. Asma