The latest server.c rev 1.76 does produce warnings when compiled with  
the MinGW tools:

server.c: In function 'start_inferior':
server.c:107: warning: implicit declaration of function 'alloca'
server.c:107: warning: incompatible implicit declaration of built-in  
function 'alloca'
server.c: In function 'handle_search_memory_1':
server.c:356: warning: implicit declaration of function 'memmem'
server.c:356: warning: assignment makes pointer from integer without a  
cast


In addition, linking of gdbserver.exe fails because of undefined  
references:

remote-utils.o:remote-utils.c:(.text+0x1057): undefined reference to  
`_disable_packet_Tthread'
server.o:server.c:(.text+0x9c6): undefined reference to  
`_disable_packet_qC'
server.o:server.c:(.text+0xa6f): undefined reference to  
`_disable_packet_qfThreadInfo'
server.o:server.c:(.text+0x20b4): undefined reference to  
`_disable_packet_vCont'
server.o:server.c:(.text+0x264a): undefined reference to  
`_disable_packet_vCont'
server.o:server.c:(.text+0x2670): undefined reference to  
`_disable_packet_Tthread'
server.o:server.c:(.text+0x2696): undefined reference to  
`_disable_packet_qC'
server.o:server.c:(.text+0x26bc): undefined reference to  
`_disable_packet_qfThreadInfo'
server.o:server.c:(.text+0x26df): undefined reference to  
`_disable_packet_vCont'
server.o:server.c:(.text+0x26e9): undefined reference to  
`_disable_packet_Tthread'
server.o:server.c:(.text+0x26f3): undefined reference to  
`_disable_packet_qC'
server.o:server.c:(.text+0x26fd): undefined reference to  
`_disable_packet_qfThreadInfo'
collect2: ld returned 1 exit status


MinGW defines alloca() in <malloc.h> and memmem() is not built-in. I  
think this should eventually be addressed in the configure script,  
however, as a quick fix, I added at the top of server.c:

#if USE_WIN32API
#include <malloc.h>
void *memmem (const void *haystack_start, size_t haystack_len, const  
void *needle_start, size_t needle_len);
#endif


In order to resolve the linking errors, the definition of the  
respective variables must be moved out of the conditional block  
(#ifdef SIGTTOU ... #endif), because they are used also within non- 
conditional code in remote-utils.c and in server.c.

I attached a .diff to this message, wich addresses both issues,  
although, there might be better ways to address 'em.

Best regards

Rolf Jansen