tree c90faf78a1eae24689f40fa12d425807d894c7f8
parent 5c4b9850c21009f20042b1e3920e602f6f6df30f
author Pau Espin Pedrol <pespin@sysmocom.de> 1564411462 +0200
committer pespin <pespin@sysmocom.de> 1564491089 +0000

gsm0808_test: Fix wrong use of memcp

After recent system upgrade, gcc 9.1.0, I started getting gsm0808_test
failing locally:
Assert failed memcmp(&enc_ct, &dec_ct, sizeof(enc_ct)) == 0 libosmocore/tests/gsm0808/gsm0808_test.c:992

During investigation with gdb, fields of both structures seem to contain
same values. However, closer lookup gives some hints on why it fails:
(gdb) print memcmp(&enc_ct, &dec_ct, sizeof(enc_ct))
$1 = 85
(gdb) print memcmp(&enc_ct, &dec_ct, 12)
$14 = 85
(gdb) print ((uint8_t*)&enc_ct)[11]
$15 = 85 'U'
(gdb) print ((uint8_t*)&dec_ct)[11]
$16 = 0 '\000'

So the 12th byte in struct gsm0808_channel_type is basically an
alignment padding byte added by the compiler (to align perm_spch_len to
4-byte alignment). Since both compared structs are initialized without
memset(0) but using compiler's designated initializers, it seems the compiler
decided it's no longer needed to zero the padding byte, making memcp fail in
this case.

In order to avoid the failure, let's properly check every field instead
of using memcp here.

Change-Id: I17fe7a0a5dc650f050bba1f47d071be749550729