Keil Logo

Technical Support

On-Line Manuals

Compiler User Guide

Preface Overview of the Compiler Getting Started with the Compiler Compiler Features Compiler Coding Practices Compiler Diagnostic Messages Using the Inline and Embedded Assemblers of the AR Compiler Command-line Options -Aopt --allow_fpreg_for_nonfpdata, --no_allow_fpreg_for_ --allow_null_this, --no_allow_null_this --alternative_tokens, --no_alternative_tokens --anachronisms, --no_anachronisms --apcs=qualifier...qualifier --arm --arm_only --asm --asm_dir=directory_name --autoinline, --no_autoinline --bigend --bitband --branch_tables, --no_branch_tables --brief_diagnostics, --no_brief_diagnostics --bss_threshold=num -c -C --c90 --c99 --code_gen, --no_code_gen --comment_section, --no_comment_section --compatible=name --compile_all_input, --no_compile_all_input --conditionalize, --no_conditionalize --cpp --cpp11 --cpp_compat --cpu=list --cpu=name --create_pch=filename -Dname[(parm-list)][=def] --data_reorder, --no_data_reorder --debug, --no_debug --debug_macros, --no_debug_macros --default_extension=ext --dep_name, --no_dep_name --depend=filename --depend_dir=directory_name --depend_format=string --depend_single_line, --no_depend_single_line --depend_system_headers, --no_depend_system_header --depend_target=target --diag_error=tag[,tag,...] --diag_remark=tag[,tag,...] --diag_style=arm|ide|gnu compiler option --diag_suppress=tag[,tag,...] --diag_suppress=optimizations --diag_warning=tag[,tag,...] --diag_warning=optimizations --dollar, --no_dollar --dwarf2 --dwarf3 -E --echo --emit_frame_directives, --no_emit_frame_directive --enum_is_int --errors=filename --exceptions, --no_exceptions --exceptions_unwind, --no_exceptions_unwind --execute_only --extended_initializers, --no_extended_initializer --feedback=filename --float_literal_pools, --no_float_literal_pools --force_new_nothrow, --no_force_new_nothrow --forceinline --fp16_format=format --fpmode=model --fpu=list --fpu=name --friend_injection, --no_friend_injection -g --global_reg=reg_name[,reg_name,...] --gnu --guiding_decls, --no_guiding_decls --help -Idir[,dir,...] --ignore_missing_headers --implicit_include, --no_implicit_include --implicit_include_searches, --no_implicit_include --implicit_key_function, --no_implicit_key_functio --implicit_typename, --no_implicit_typename --info=totals --inline, --no_inline --integer_literal_pools, --no_integer_literal_pool --interface_enums_are_32_bit --interleave -Jdir[,dir,...] --kandr_include -Lopt --library_interface=lib --library_type=lib --liclinger=seconds --link_all_input, --no_link_all_input --list --list_dir=directory_name --list_macros --littleend --locale=lang_country --long_long --loop_optimization_level=opt --loose_implicit_cast --lower_ropi, --no_lower_ropi --lower_rwpi, --no_lower_rwpi -M --md --message_locale=lang_country[.codepage] --min_array_alignment=opt --mm --multibyte_chars, --no_multibyte_chars --multifile, --no_multifile --multiply_latency=cycles --narrow_volatile_bitfields --nonstd_qualifier_deduction, --no_nonstd_qualifie -o filename -Onum --old_specializations, --no_old_specializations --old_style_preprocessing --omf_browse --ool_section_name, --no_ool_section_name -Ospace -Otime --output_dir=directory_name -P --parse_templates, --no_parse_templates --pch --pch_dir=dir --pch_messages, --no_pch_messages --pch_verbose, --no_pch_verbose --pending_instantiations=n --phony_targets --pointer_alignment=num --preinclude=filename --preprocess_assembly --preprocessed --protect_stack, --no_protect_stack --reassociate_saturation, --no_reassociate_saturat --reduce_paths, --no_reduce_paths --remarks --remove_unneeded_entities, --no_remove_unneeded_e --restrict, --no_restrict --retain=option --rtti, --no_rtti --rtti_data, --no_rtti_data -S --share_inlineable_strings, --no_share_inlineable_ --show_cmdline --signed_bitfields, --unsigned_bitfields --signed_chars, --unsigned_chars --split_ldm --split_sections --strict, --no_strict --strict_warnings --string_literal_pools, --no_string_literal_pools --sys_include --thumb --trigraphs, --no_trigraphs --type_traits_helpers, --no_type_traits_helpers -Uname --unaligned_access, --no_unaligned_access --use_frame_pointer, --no_use_frame_pointer --use_pch=filename --using_std, --no_using_std --version_number --vfe, --no_vfe --via=filename --vla, --no_vla --vsn -W --wchar, --no_wchar --wchar16 --wchar32 --whole_program --wrap_diagnostics, --no_wrap_diagnostics Language Extensions Compiler-specific Features C and C++ Implementation Details What is Semihosting? Via File Syntax Summary Table of GNU Language Extensions Standard C Implementation Definition Standard C++ Implementation Definition C and C++ Compiler Implementation Limits

--interface_enums_are_32_bit

7.86 --interface_enums_are_32_bit

Helps to provide compatibility between external code interfaces, with regard to the size of enumerated types.

Usage

It is not possible to link an object file compiled with --enum_is_int, with another object file that is compiled without --enum_is_int. The linker is unable to determine whether or not the enumerated types are used in a way that affects the external interfaces, so on detecting these build differences, it produces a warning or an error. You can avoid this by compiling with --interface_enums_are_32_bit. The resulting object file can then be linked with any other object file, without the linker-detected conflict that arises from different enumeration type sizes.

Note

When you use this option, you are making a promise to the compiler that all the enumerated types used in your external interfaces are 32 bits wide. For example, if you ensure that every enum you declare includes at least one value larger than 2 to the power of 16, the compiler is forced to make the enum 32 bits wide, whether or not you use --enum_is_int. It is up to you to ensure that the promise you are making to the compiler is true. (Another method of satisfying this condition is to ensure that you have no enums in your external interface.)

Default

By default, the smallest data type that can hold the values of all enumerators is used.
Related reference
Non-ConfidentialPDF file icon PDF versionARM DUI0375H
Copyright © 2007, 2008, 2011, 2012, 2014-2016 ARM. All rights reserved. 
  Arm logo
Important information

This site uses cookies to store information on your computer. By continuing to use our site, you consent to our cookies.

Change Settings

Privacy Policy Update

Arm’s Privacy Policy has been updated. By continuing to use our site, you consent to Arm’s Privacy Policy. Please review our Privacy Policy to learn more about our collection, use and transfers
of your data.