This patch, the next step in my -Wc++-compat work, turns on warnings for assignments to variables of enum type. There are two patches here. The first, smaller, patch enables the warning. The main work here is to add a parameter to build_modify_expr, so that we can emit warnings for assignments to bitfields in structs with enum type. The additional parameter is required because at the point of convert_for_assignment, the original enum type has been replaced by a bitfield integer type. This patch requires approval from the C and C++ frontend maintainers. Please also take a quick look at the new test case, and let me know if there are any other cases I should check. The second patch fixes all the cases I discovered where this warning is triggered when bootstrapping gcc. As before I tested building the arm, pa, ia64, mips, ppc, s390, sparc, and spu backends. I verified that they continued to work the same way on a range of preprocessed test cases. This second patch requires approach from the C++, Java, and Fortran maintainers. It might be useful for the OpenMP maintainers to look at the changes to gimplify_omp_for, which were slightly less mechanical than the other changes. Bootstrapped and tested on i686-pc-linux-gnu. OK for mainline? Ian First patch, adding the warning: gcc/ChangeLog: 2009-04-22 Ian Lance Taylor * c-typeck.c (build_modify_expr): Add lhs_origtype parameter. Change all callers. Issue a -Wc++-compat warning using lhs_origtype if necessary. (convert_for_assignment): Issue -Wc++-compat warnings about invalid conversions to enum type on assignment. * c-common.h (build_modify_expr): Update declaration. cp/ChangeLog: 2009-04-22 Ian Lance Taylor * typeck.c (build_modify_expr): Add lhs_origtype parameter. Change all callers. objc/ChangeLog: 2009-04-22 Ian Lance Taylor * objc-act.c (get_super_receiver): Update calls to build_modify_expr to pass new argument. testsuite/ChangeLog: 2009-04-22 Ian Lance Taylor * gcc.dg/Wcxx-compat-4.c: New testcase. ================================================== Second patch, fixing gcc code to avoid the warning: gcc/ChangeLog: 2009-04-22 Ian Lance Taylor * combine.c (record_value_for_reg): Change 0 to VOIDmode, twice. (record_dead_and_set_regs): Likewise. * df.h (struct df_mw_hardreg): Change flags field to int. (struct df_base_ref): Likewise. (struct df): Change changeable_flags field to int. * df-scan.c (df_defs_record): Change clobber_flags to int. * dwarf2.h (enum dwarf_tag): Make lo_user and hi_user values enum constants rather than #define macros. (enum dwarf_attribute, enum dwarf_location_atom): Likewise. (enum dwarf_type, enum dwarf_endianity_encoding): Likewise. (enum dwarf_calling_convention): Likewise. (enum dwarf_line_number_x_ops): Likewise. (enum dwarf_call_frame_info): Likewise. (enum dwarf_source_language): Likewise. * dwarf2out.c (int_loc_descriptor): Add cast to enum type. (add_calling_convention_attribute): Likewise. * fold-const.c (fold_undefer_overflow_warnings): Add cast to enum type. (combine_comparisons): Change compcode to int. Add cast to enum type. * genrecog.c (maybe_both_true_2): Change c to int. (write_switch): Likewise. Add cast to enum type. * gimplify.c (gimplify_omp_for): Handle return values from gimplify_expr using MIN rather than bitwise or. (gimplify_expr): Add cast to enum type. * ipa-prop.c (update_jump_functions_after_inlining): Change IPA_BOTTOM to IPA_JF_UNKNOWN. * ira.c (setup_class_subset_and_memory_move_costs): Change mode to int. Add casts to enum type. (setup_cover_and_important_classes): Change cl to int. Add casts to enum type. (setup_class_translate): Change cl and mode to int. (ira_init_once): Change mode to int. (free_register_move_costs): Likewise. (setup_prohibited_mode_move_regs): Add casts to enum type. * langhooks.c (add_builtin_function_common): Rework assertion that value fits bitfield. * mcf.c (add_fixup_edge): Change type parameter to edge_type. * omega.c (omega_do_elimination): Avoid math on enum types. * optabs.c (expand_vec_shift_expr): Remove casts to int. * opts.c (set_debug_level): Change 2 to enum constant. Use new int local to handle integral_argment value. * regmove.c (try_auto_increment): Change PUT_MODE to PUT_REG_NOTE_KIND. * reload.c (push_secondary_reload): Add casts to enum type. (secondary_reload_class, find_valid_class): Likewise. * reload1.c (emit_input_reload_insns): Likewise. * rtl.h (NOTE_VAR_LOCATION_STATUS): Likewise. * sel-sched.c (init_hard_regs_data): Change cur_mode to int. * sel-sched-ir.c (hash_with_unspec_callback): Change 0 to enum constant. * tree.c (build_common_builtin_nodes): Add casts to enum type. * tree-complex.c (complex_lattice_t): Typedef to int rather than enum type. (expand_complex_libcall): Add casts to enum type. * tree-into-ssa.c (get_ssa_name_ann): Change 0 to enum constant. * tree-vect-loop.c (vect_model_reduction_cost): Compare reduc_code with ERROR_MARK, not NUM_TREE_CODES. (vect_create_epilog_for_reduction): Likewise. (vectorizable_reduction): Don't initialize epiloc_reduc_code. When not using it, set it to ERROR_MARK rather than NUM_TREE_CODES. * tree-vect-patterns.c (vect_pattern_recog_1): Change vec_mode to enum machine_mode. * tree-vect-stmts.c (new_stmt_vec_info): Change 0 to vect_unused_in_loop. Change 0 to loop_vect. * tree-vectorizer.c (vect_set_verbosity_level): Add casts to enum type. * var-tracking.c (get_init_value): Change return type to enum var_init_status. * vec.h (DEF_VEC_FUNC_P) [iterate]: Cast 0 to type T. * config/arm/arm.c (fp_model_for_fpu): Change to array to enum arm_fp_model. (arm_override_options): Add casts to enum type. (arm_emit_tls_decoration): Likewise. * config/i386/i386.c (ix86_function_specific_restore): Add casts to enum type. * config/i386/i386-c.c (ix86_pragma_target_parse): Likewise. * config/ia64/ia64.c (ia64_expand_compare): Change magic to int. * config/rs6000/rs6000.c (rs6000_override_options): Add casts to enum type. * config/s390/s390.c (code_for_builtin_64): Change to array of enum insn_code. (code_for_builtin_31): Likewise. (s390_expand_builtin): Change code_for_builtin to enum insn_code const *. * config/sparc/sparc.c (sparc_override_options): Change value field in struct code_model to enum cmodel. In initializer change 0 to NULL and add cast to enum type. * config/spu/spu-c.c (spu_resolve_overloaded_builtin): Change new_fcode to int. cp/ChangeLog: 2009-04-22 Ian Lance Taylor * call.c (build_temp): Change 0 to enum constant. * cp-tree.h (cp_lvalue_kind): Typedef to int rather than enum type. * cp-gimplify.c (cp_gimplify_expr): Add cast to enum type. * decl2.c (constrain_visibility): Likewise. * parser.c (cp_lexer_get_preprocessor_token): Likewise. (cp_parser_flags): Typedef to int rather than enum type. (cp_parser_expression_stack_entry): Change prec field to enum cp_parser_prec. fortran/ChangeLog: 2009-04-22 Ian Lance Taylor * gfortran.h (enum gfc_symbol_type): New named enum type, broken out of struct gfc_symbol. (struct gfc_symbol): Use enum gfc_symbol_type. (enum gfc_array_ref_dimen_type): New named enum type, broken out of struct gfc_array_ref). (struct gfc_array_ref): Use enum gfc_array_ref_dimen_type. (mod_pointee_as): Update declaration. * decl.c (add_global_entry): Change type to enum gfc_symbol_type. (gfc_mod_pointee_as): Change return type to "match". * module.c (mio_array_ref): Add cast to enum type. (mio_symbol): Likewise. * resolve.c (resolve_global_procedure): Change type to enum gfc_symbol_type. * trans-io.c (gfc_build_st_parameter): Change type to unsigned int. java/ChangeLog: 2009-04-22 Ian Lance Taylor * jcf-parse.c (handle_constant): Add cast to enum type. ================================================== First patch, adding the warning: