memdebug: include in unity batch

Before this patch `memdebug.c` was compiled as a separate source in
unity builds. This was necessary because `memdebug.c` failed to compile
if `memdebug.h` was included before it, in `CURLDEBUG` mode. This patch
fixes this issue and allows to compile `memdebug.c` as part of the unity
source batch. This removes an exception and makes builds perform a notch
better.

- introduce `CURL_SCLOSE()` macro as an immutable synonym of `sclose()`.
- memdebug: replace `sclose()` reference with `CURL_SCLOSE()` to compile
  as expected when `sclose()` is overridden by `memdebug.h`.
- memdebug: make it not break when including `memdebug.h` before it in
  `CURLDEBUG` mode. Do this by calling low-level functions as
  `(function)`.
- autotools, cmake: drop memdebug exception, include it like any other
  source file. This is now possible because `memdebug.c` doesn't break
  if `memdebug.h` was included before it, in `CURLDEBUG` builds.
- mk-unity: drop `--exclude` option. No longer used after this patch.
- drop `MEMDEBUG_NODEFINES` macro hack. No longer necessary.

Ref: #16747
Closes #16746
Closes #16738
Closes #17631

lib/memdebug.c

@@ -30,8 +30,6 @@
 
 #include "urldata.h"
 
-#define MEMDEBUG_NODEFINES /* do not redefine the standard functions */
-
 /* The last 3 #include files should be in this order */
 #include "curl_printf.h"
 #include "curl_memory.h"
@@ -70,7 +68,7 @@ static void curl_dbg_cleanup(void)
   if(curl_dbg_logfile &&
      curl_dbg_logfile != stderr &&
      curl_dbg_logfile != stdout) {
-    fclose(curl_dbg_logfile);
+    (fclose)(curl_dbg_logfile);
   }
   curl_dbg_logfile = NULL;
 }
@@ -80,7 +78,7 @@ void curl_dbg_memdebug(const char *logname)
 {
   if(!curl_dbg_logfile) {
     if(logname && *logname)
-      curl_dbg_logfile = fopen(logname, FOPEN_WRITETEXT);
+      curl_dbg_logfile = (fopen)(logname, FOPEN_WRITETEXT);
     else
       curl_dbg_logfile = stderr;
 #ifdef MEMDEBUG_LOG_SYNC
@@ -309,7 +307,7 @@ curl_socket_t curl_dbg_socket(int domain, int type, int protocol,
   if(countcheck("socket", line, source))
     return CURL_SOCKET_BAD;
 
-  sockfd = socket(domain, type, protocol);
+  sockfd = (socket)(domain, type, protocol);
 
   if(source && (sockfd != CURL_SOCKET_BAD))
     curl_dbg_log("FD %s:%d socket() = %" FMT_SOCKET_T "\n",
@@ -326,7 +324,7 @@ SEND_TYPE_RETV curl_dbg_send(SEND_TYPE_ARG1 sockfd,
   SEND_TYPE_RETV rc;
   if(countcheck("send", line, source))
     return -1;
-  rc = send(sockfd, buf, len, flags);
+  rc = (send)(sockfd, buf, len, flags);
   if(source)
     curl_dbg_log("SEND %s:%d send(%lu) = %ld\n",
                 source, line, (unsigned long)len, (long)rc);
@@ -340,7 +338,7 @@ RECV_TYPE_RETV curl_dbg_recv(RECV_TYPE_ARG1 sockfd, RECV_TYPE_ARG2 buf,
   RECV_TYPE_RETV rc;
   if(countcheck("recv", line, source))
     return -1;
-  rc = recv(sockfd, buf, len, flags);
+  rc = (recv)(sockfd, buf, len, flags);
   if(source)
     curl_dbg_log("RECV %s:%d recv(%lu) = %ld\n",
                 source, line, (unsigned long)len, (long)rc);
@@ -352,7 +350,7 @@ int curl_dbg_socketpair(int domain, int type, int protocol,
                        curl_socket_t socket_vector[2],
                        int line, const char *source)
 {
-  int res = socketpair(domain, type, protocol, socket_vector);
+  int res = (socketpair)(domain, type, protocol, socket_vector);
 
   if(source && (0 == res))
     curl_dbg_log("FD %s:%d socketpair() = "
@@ -369,7 +367,7 @@ curl_socket_t curl_dbg_accept(curl_socket_t s, void *saddr, void *saddrlen,
   struct sockaddr *addr = (struct sockaddr *)saddr;
   curl_socklen_t *addrlen = (curl_socklen_t *)saddrlen;
 
-  curl_socket_t sockfd = accept(s, addr, addrlen);
+  curl_socket_t sockfd = (accept)(s, addr, addrlen);
 
   if(source && (sockfd != CURL_SOCKET_BAD))
     curl_dbg_log("FD %s:%d accept() = %" FMT_SOCKET_T "\n",
@@ -386,7 +384,7 @@ curl_socket_t curl_dbg_accept4(curl_socket_t s, void *saddr, void *saddrlen,
   struct sockaddr *addr = (struct sockaddr *)saddr;
   curl_socklen_t *addrlen = (curl_socklen_t *)saddrlen;
 
-  curl_socket_t sockfd = accept4(s, addr, addrlen, flags);
+  curl_socket_t sockfd = (accept4)(s, addr, addrlen, flags);
 
   if(source && (sockfd != CURL_SOCKET_BAD))
     curl_dbg_log("FD %s:%d accept() = %" FMT_SOCKET_T "\n",
@@ -407,7 +405,7 @@ void curl_dbg_mark_sclose(curl_socket_t sockfd, int line, const char *source)
 /* this is our own defined way to close sockets on *ALL* platforms */
 int curl_dbg_sclose(curl_socket_t sockfd, int line, const char *source)
 {
-  int res = sclose(sockfd);
+  int res = CURL_SCLOSE(sockfd);
   curl_dbg_mark_sclose(sockfd, line, source);
   return res;
 }
@@ -416,7 +414,7 @@ ALLOC_FUNC
 FILE *curl_dbg_fopen(const char *file, const char *mode,
                      int line, const char *source)
 {
-  FILE *res = fopen(file, mode);
+  FILE *res = (fopen)(file, mode);
 
   if(source)
     curl_dbg_log("FILE %s:%d fopen(\"%s\",\"%s\") = %p\n",
@@ -429,7 +427,7 @@ ALLOC_FUNC
 FILE *curl_dbg_fdopen(int filedes, const char *mode,
                       int line, const char *source)
 {
-  FILE *res = fdopen(filedes, mode);
+  FILE *res = (fdopen)(filedes, mode);
   if(source)
     curl_dbg_log("FILE %s:%d fdopen(\"%d\",\"%s\") = %p\n",
                  source, line, filedes, mode, (void *)res);
@@ -446,7 +444,7 @@ int curl_dbg_fclose(FILE *file, int line, const char *source)
     curl_dbg_log("FILE %s:%d fclose(%p)\n",
                  source, line, (void *)file);
 
-  res = fclose(file);
+  res = (fclose)(file);
 
   return res;
 }
@@ -469,7 +467,7 @@ void curl_dbg_log(const char *format, ...)
     nchars = (int)sizeof(buf) - 1;
 
   if(nchars > 0)
-    fwrite(buf, 1, (size_t)nchars, curl_dbg_logfile);
+    (fwrite)(buf, 1, (size_t)nchars, curl_dbg_logfile);
 }
 
 #endif /* CURLDEBUG */