Compiler Warning - x86_64_linux

[f. b.]

Hello together,

while compiling snap7, I got this warning:

In file included from /usr/include/string.h:495,
                 from /usr/include/c++/9/cstring:42,
                 from ../../src/sys/snap_platform.h:100,
                 from ../../src/sys/snap_msgsock.h:29,
                 from ../../src/sys/snap_tcpsrvr.h:29,
                 from ../../src/core/s7_server.h:29,
                 from ../../src/core/s7_server.cpp:26:
In function ‘void* memcpy(void*, const void*, size_t)’,
    inlined from ‘void TS7Worker::SZLSystemState()’ at ../../src/core/s7_server.cpp:1247:11:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:34:33: warning: ‘void* __builtin_memcpy(void*, const void*, long unsigned int)’ reading 6 bytes from a region of size 4 [-Wstringop-overflow=]
   34 |   return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest));
      |          ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

g++: 9.3.0
OS: Ubuntu

[Rémi Thebault]

Hi

I have the same warning.
There is a typo in TS7Worker::SZLSystemState():

--- a/src/core/s7_server.cpp
+++ b/src/core/s7_server.cpp
@@ -1244,7 +1244,7 @@ void TS7Worker::SZLSystemState()
 {
     SZL.Answer.Header.DataLen=SwapWord(sizeof(SZLSysState));
     SZL.ResParams->Err =0x0000;

-    memcpy(SZL.ResData,&SZLNotAvail,sizeof(SZLSysState));
+    memcpy(SZL.ResData,&SZLSysState,sizeof(SZLSysState));
     isoSendBuffer(&SZL.Answer,28);
     SZL.SZLDone=true;
 }