Warn on use of undefined macros

configure.ac

@@ -770,7 +770,7 @@ AS_CASE([$ocaml_cv_cc_vendor],
   [outputobj='-o '
   warn_error_flag='-Werror'
   cc_warnings="-Wall -Wint-conversion -Wstrict-prototypes \
--Wold-style-definition"])
+-Wold-style-definition -Wundef"])
 
 # Use -Wold-style-declaration if supported
 AX_CHECK_COMPILE_FLAG([-Wold-style-declaration],

otherlibs/unix/getcwd.c

@@ -21,7 +21,7 @@
 #include <caml/osdeps.h>
 #include "unixsupport.h"
 
-#if !defined (_WIN32) && !macintosh
+#if !defined(_WIN32)
 #include <sys/param.h>
 #endif
 

otherlibs/unix/gethost.c

@@ -31,11 +31,6 @@
 
 #define NETDB_BUFFER_SIZE 10000
 
-#ifdef _WIN32
-#define GETHOSTBYADDR_IS_REENTRANT 1
-#define GETHOSTBYNAME_IS_REENTRANT 1
-#endif
-
 static value alloc_one_addr_4(char const *a)
 {
   return caml_alloc_initialized_string(4, a);
@@ -101,7 +96,15 @@ CAMLprim value caml_unix_gethostbyaddr(value a)
 #if HAS_IPV6
   }
 #endif
-#if HAS_GETHOSTBYADDR_R == 7
+#if !defined(HAS_GETHOSTBYADDR_R)
+#ifdef _WIN32
+  caml_enter_blocking_section();
+#endif
+  hp = gethostbyaddr(adr, addr_len, addr_type);
+#ifdef _WIN32
+  caml_leave_blocking_section();
+#endif
+#elif HAS_GETHOSTBYADDR_R == 7
   struct hostent h;
   char buffer[NETDB_BUFFER_SIZE];
   int h_errnop;
@@ -118,14 +121,6 @@ CAMLprim value caml_unix_gethostbyaddr(value a)
                        &h, buffer, sizeof(buffer), &hp, &h_errnop);
   caml_leave_blocking_section();
   if (rc != 0) hp = NULL;
-#else
-#ifdef GETHOSTBYADDR_IS_REENTRANT
-  caml_enter_blocking_section();
-#endif
-  hp = gethostbyaddr(adr, addr_len, addr_type);
-#ifdef GETHOSTBYADDR_IS_REENTRANT
-  caml_leave_blocking_section();
-#endif
 #endif
   if (hp == (struct hostent *) NULL) caml_raise_not_found();
   return alloc_host_entry(hp);
@@ -135,7 +130,7 @@ CAMLprim value caml_unix_gethostbyname(value name)
 {
   struct hostent * hp;
   char * hostname;
-#if HAS_GETHOSTBYNAME_R
+#ifdef HAS_GETHOSTBYNAME_R
   struct hostent h;
   char buffer[NETDB_BUFFER_SIZE];
   int err;
@@ -145,7 +140,15 @@ CAMLprim value caml_unix_gethostbyname(value name)
 
   hostname = caml_stat_strdup(String_val(name));
 
-#if HAS_GETHOSTBYNAME_R == 5
+#if !defined(HAS_GETHOSTBYNAME_R)
+#ifdef _WIN32
+  caml_enter_blocking_section();
+#endif
+  hp = gethostbyname(hostname);
+#ifdef _WIN32
+  caml_leave_blocking_section();
+#endif
+#elif HAS_GETHOSTBYNAME_R == 5
   {
     caml_enter_blocking_section();
     hp = gethostbyname_r(hostname, &h, buffer, sizeof(buffer), &err);
@@ -159,14 +162,6 @@ CAMLprim value caml_unix_gethostbyname(value name)
     caml_leave_blocking_section();
     if (rc != 0) hp = NULL;
   }
-#else
-#ifdef GETHOSTBYNAME_IS_REENTRANT
-  caml_enter_blocking_section();
-#endif
-  hp = gethostbyname(hostname);
-#ifdef GETHOSTBYNAME_IS_REENTRANT
-  caml_leave_blocking_section();
-#endif
 #endif
 
   caml_stat_free(hostname);

runtime/misc.c

@@ -15,7 +15,7 @@
 
 #define CAML_INTERNALS
 
-#if _MSC_VER >= 1400 && _MSC_VER < 1700
+#if defined(_MSC_VER) && _MSC_VER >= 1400 && _MSC_VER < 1700
 /* Microsoft introduced a regression in Visual Studio 2005 (technically it's
    not present in the Windows Server 2003 SDK which has a pre-release version)
    and the abort function ceased to be declared __declspec(noreturn). This was

runtime/startup_byt.c

@@ -404,7 +404,7 @@ static void do_print_config(void)
          "false");
 #endif
   printf("windows_unicode: %s\n",
-#if WINDOWS_UNICODE
+#if defined(WINDOWS_UNICODE) && WINDOWS_UNICODE != 0
          "true");
 #else
          "false");