Generated code causes warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]

[StefanHri]

Using the latest version zcbor in the uoscore-uedhoc causes the following warnings:

src/cbor/edhoc_encode_bstr_type.c: In function ‘cbor_encode_bstr_type_b_str’:
src/cbor/edhoc_encode_bstr_type.c:48:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   48 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/edhoc_encode_data_2.c
src/cbor/edhoc_encode_data_2.c: In function ‘cbor_encode_data_2’:
src/cbor/edhoc_encode_data_2.c:72:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   72 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/edhoc_encode_enc_structure.c
src/cbor/edhoc_encode_enc_structure.c: In function ‘cbor_encode_edhoc_enc_structure’:
src/cbor/edhoc_encode_enc_structure.c:50:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   50 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/edhoc_encode_id_cred_x.c
src/cbor/edhoc_encode_id_cred_x.c: In function ‘cbor_encode_id_cred_x_map’:
src/cbor/edhoc_encode_id_cred_x.c:235:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
  235 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/edhoc_encode_info.c
src/cbor/edhoc_encode_info.c: In function ‘cbor_encode_info’:
src/cbor/edhoc_encode_info.c:50:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   50 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/edhoc_encode_int_type.c
src/cbor/edhoc_encode_int_type.c: In function ‘cbor_encode_int_type_i’:
src/cbor/edhoc_encode_int_type.c:48:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   48 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/edhoc_encode_message_1.c
src/cbor/edhoc_encode_message_1.c: In function ‘cbor_encode_message_1’:
src/cbor/edhoc_encode_message_1.c:56:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   56 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/edhoc_encode_message_2.c
src/cbor/edhoc_encode_message_2.c: In function ‘cbor_encode_m2’:
src/cbor/edhoc_encode_message_2.c:51:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   51 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/edhoc_encode_message_3.c
src/cbor/edhoc_encode_message_3.c: In function ‘cbor_encode_m3_CIPHERTEXT_3’:
src/cbor/edhoc_encode_message_3.c:48:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   48 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/edhoc_encode_message_error.c
src/cbor/edhoc_encode_message_error.c: In function ‘cbor_encode_message_error’:
src/cbor/edhoc_encode_message_error.c:90:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   90 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/edhoc_encode_sig_structure.c
src/cbor/edhoc_encode_sig_structure.c: In function ‘cbor_encode_sig_structure’:
src/cbor/edhoc_encode_sig_structure.c:51:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   51 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/edhoc_encode_th2.c
src/cbor/edhoc_encode_th2.c: In function ‘cbor_encode_th2’:
src/cbor/edhoc_encode_th2.c:52:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   52 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/oscore_aad_array.c
src/cbor/oscore_aad_array.c: In function ‘cbor_encode_aad_array’:
src/cbor/oscore_aad_array.c:54:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   54 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/oscore_enc_structure.c
src/cbor/oscore_enc_structure.c: In function ‘cbor_encode_oscore_enc_structure’:
src/cbor/oscore_enc_structure.c:50:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   50 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,
      |                                                           ^
[Compile] src/cbor/oscore_info.c
src/cbor/oscore_info.c: In function ‘cbor_encode_oscore_info’:
src/cbor/oscore_info.c:56:59: warning: cast discards ‘const’ qualifier from pointer target type [-Wcast-qual]
   56 |         return zcbor_entry_function(payload, payload_len, (void *)input, payload_len_out, states,

Generally the uoscore-uedhoc project is using the following warning flags:

EXTENDED_CFLAGS += -Wcast-qual
EXTENDED_CFLAGS += -Wconversion
EXTENDED_CFLAGS += -Wexit-time-destructors
EXTENDED_CFLAGS += -Wglobal-constructors
EXTENDED_CFLAGS += -Wmissing-noreturn
EXTENDED_CFLAGS += -Wmissing-prototypes
EXTENDED_CFLAGS += -Wno-missing-braces
EXTENDED_CFLAGS += -Wold-style-cast
EXTENDED_CFLAGS += -Wshadow
EXTENDED_CFLAGS += -Wweak-vtables
EXTENDED_CFLAGS += -Wall
EXTENDED_CFLAGS += -Wextra
EXTENDED_CFLAGS += -Wpedantic
EXTENDED_CFLAGS += -Wstack-exhausted
EXTENDED_CFLAGS += -Wconversion

Would it be possible to make sure that the code generated by zcbor is not triggering those? Thanks!

[oyvindronningstad]

Which C standard are you using? My experience is that the different -W flags behave differently between them.

[StefanHri]

c11