Initial Mingw support with Makefile.

Also add a macro JANET_MSVC to distinguish between
a windows build (JANET_WINDOWS) and a build with msvc.

Makefile

@@ -77,6 +77,12 @@ ifeq ($(shell uname -o), Android)
 endif
 endif
 
+# Mingw
+ifeq ($(findstring MINGW,$(UNAME)), MINGW)
+	CLIBS:=-lws2_32 -lpsapi -lwsock32
+	LDFLAGS:=
+endif
+
 $(shell mkdir -p build/core build/c build/boot)
 all: $(JANET_TARGET) $(JANET_LIBRARY) $(JANET_STATIC_LIBRARY) build/janet.h
 

src/core/abstract.c

@@ -98,11 +98,11 @@ size_t janet_os_rwlock_size(void) {
 }
 
 static int32_t janet_incref(JanetAbstractHead *ab) {
-    return InterlockedIncrement(&ab->gc.data.refcount);
+    return InterlockedIncrement((LONG volatile *) &ab->gc.data.refcount);
 }
 
 static int32_t janet_decref(JanetAbstractHead *ab) {
-    return InterlockedDecrement(&ab->gc.data.refcount);
+    return InterlockedDecrement((LONG volatile *) &ab->gc.data.refcount);
 }
 
 void janet_os_mutex_init(JanetOSMutex *mutex) {

src/core/ev.c

@@ -2273,7 +2273,7 @@ JanetAsyncStatus ev_machine_read(JanetListenerState *s, JanetAsyncEvent event) {
 #ifdef JANET_NET
             if (state->mode == JANET_ASYNC_READMODE_RECVFROM) {
                 state->wbuf.len = (ULONG) chunk_size;
-                state->wbuf.buf = state->chunk_buf;
+                state->wbuf.buf = (char *) state->chunk_buf;
                 status = WSARecvFrom((SOCKET) s->stream->handle, &state->wbuf, 1,
                                      NULL, &state->flags, &state->from, &state->fromlen, &state->overlapped, NULL);
                 if (status && (WSA_IO_PENDING != WSAGetLastError())) {
@@ -2664,15 +2664,15 @@ int janet_make_pipe(JanetHandle handles[2], int mode) {
      * so we lift from the windows source code and modify for our own version.
      */
     JanetHandle shandle, chandle;
-    UCHAR PipeNameBuffer[MAX_PATH];
+    CHAR PipeNameBuffer[MAX_PATH];
     SECURITY_ATTRIBUTES saAttr;
     memset(&saAttr, 0, sizeof(saAttr));
     saAttr.nLength = sizeof(saAttr);
     saAttr.bInheritHandle = TRUE;
     sprintf(PipeNameBuffer,
             "\\\\.\\Pipe\\JanetPipeFile.%08x.%08x",
-            GetCurrentProcessId(),
+            (unsigned int) GetCurrentProcessId(),
-            InterlockedIncrement(&PipeSerialNumber));
+            (unsigned int) InterlockedIncrement(&PipeSerialNumber));
 
     /* server handle goes to subprocess */
     shandle = CreateNamedPipeA(

src/core/ffi.c

@@ -838,7 +838,6 @@ JANET_CORE_FN(cfun_ffi_signature,
             }
 
             /* Add reference items */
-            size_t old_stack_count = stack_count;
             stack_count += 2 * ref_stack_count;
             if (stack_count & 0x1) {
                 stack_count++;

src/core/net.c

@@ -34,9 +34,11 @@
 #include <windows.h>
 #include <ws2tcpip.h>
 #include <mswsock.h>
+#ifdef JANET_MSVC
 #pragma comment (lib, "Ws2_32.lib")
 #pragma comment (lib, "Mswsock.lib")
 #pragma comment (lib, "Advapi32.lib")
+#endif
 #else
 #include <arpa/inet.h>
 #include <unistd.h>
@@ -173,7 +175,6 @@ JanetAsyncStatus net_machine_accept(JanetListenerState *s, JanetAsyncEvent event
 
 JANET_NO_RETURN static void janet_sched_accept(JanetStream *stream, JanetFunction *fun) {
     Janet err;
-    SOCKET lsock = (SOCKET) stream->handle;
     JanetListenerState *s = janet_listen(stream, net_machine_accept, JANET_ASYNC_LISTEN_READ, sizeof(NetStateAccept), NULL);
     NetStateAccept *state = (NetStateAccept *)s;
     memset(&state->overlapped, 0, sizeof(WSAOVERLAPPED));
@@ -706,7 +707,7 @@ JANET_CORE_FN(cfun_net_getsockname,
     if (getsockname((JSock)js->handle, (struct sockaddr *) &ss, &slen)) {
         janet_panicf("Failed to get localname on %v: %V", argv[0], janet_ev_lasterr());
     }
-    janet_assert(slen <= sizeof(ss), "socket address truncated");
+    janet_assert(slen <= (socklen_t) sizeof(ss), "socket address truncated");
     return janet_so_getname(&ss);
 }
 
@@ -722,7 +723,7 @@ JANET_CORE_FN(cfun_net_getpeername,
     if (getpeername((JSock)js->handle, (struct sockaddr *)&ss, &slen)) {
         janet_panicf("Failed to get peername on %v: %V", argv[0], janet_ev_lasterr());
     }
-    janet_assert(slen <= sizeof(ss), "socket address truncated");
+    janet_assert(slen <= (socklen_t) sizeof(ss), "socket address truncated");
     return janet_so_getname(&ss);
 }
 

src/core/os.c

@@ -445,7 +445,7 @@ typedef struct {
 static JanetEVGenericMessage janet_proc_wait_subr(JanetEVGenericMessage args) {
     JanetProc *proc = (JanetProc *) args.argp;
     WaitForSingleObject(proc->pHandle, INFINITE);
-    GetExitCodeProcess(proc->pHandle, &args.tag);
+    GetExitCodeProcess(proc->pHandle, (LPDWORD) &args.tag);
     return args;
 }
 
@@ -902,9 +902,6 @@ static Janet os_execute_impl(int32_t argc, Janet *argv, int is_spawn) {
         janet_panic("failed to create pipes");
     }
 
-    /* Result */
-    int status = 0;
-
 #ifdef JANET_WINDOWS
 
     HANDLE pHandle, tHandle;
@@ -983,6 +980,9 @@ static Janet os_execute_impl(int32_t argc, Janet *argv, int is_spawn) {
 
 #else
 
+    /* Result */
+    int status = 0;
+
     const char **child_argv = janet_smalloc(sizeof(char *) * ((size_t) exargs.len + 1));
     for (int32_t i = 0; i < exargs.len; i++)
         child_argv[i] = janet_getcstring(exargs.items, i);
@@ -1769,9 +1769,11 @@ static Janet os_stat_changed(jstat_t *st) {
 }
 #ifdef JANET_WINDOWS
 static Janet os_stat_blocks(jstat_t *st) {
+    (void) st;
     return janet_wrap_number(0);
 }
 static Janet os_stat_blocksize(jstat_t *st) {
+    (void) st;
     return janet_wrap_number(0);
 }
 #else
@@ -2047,6 +2049,7 @@ JANET_CORE_FN(os_open,
     uint32_t stream_flags = 0;
     JanetHandle fd;
 #ifdef JANET_WINDOWS
+    (void) mode;
     DWORD desiredAccess = 0;
     DWORD shareMode = 0;
     DWORD creationDisp = 0;

src/core/util.c

@@ -39,9 +39,11 @@
 #ifdef JANET_WINDOWS
 #ifdef JANET_DYNAMIC_MODULES
 #include <psapi.h>
+#ifdef JANET_MSVC
 #pragma comment (lib, "Psapi.lib")
 #endif
 #endif
+#endif
 
 #ifdef JANET_APPLE
 #include <AvailabilityMacros.h>
@@ -863,7 +865,7 @@ int janet_cryptorand(uint8_t *out, size_t n) {
         unsigned int v;
         if (rand_s(&v))
             return -1;
-        for (int32_t j = 0; (j < sizeof(unsigned int)) && (i + j < n); j++) {
+        for (int32_t j = 0; (j < (int32_t) sizeof(unsigned int)) && (i + j < n); j++) {
             out[i + j] = v & 0xff;
             v = v >> 8;
         }

src/include/janet.h

@@ -92,6 +92,11 @@ extern "C" {
 #define JANET_WINDOWS 1
 #endif
 
+/* Check if compiling with MSVC - else assume a GCC-like compiler by default */
+#ifdef _MSC_VER
+#define JANET_MSVC
+#endif
+
 /* Check 64-bit vs 32-bit */
 #if ((defined(__x86_64__) || defined(_M_X64)) \
      && (defined(JANET_POSIX) || defined(JANET_WINDOWS))) \

src/mainclient/shell.c

@@ -296,6 +296,7 @@ static char *sdup(const char *s) {
     return memcpy(mem, s, len);
 }
 
+#ifndef _WIN32
 static int curpos(void) {
     char buf[32];
     int cols, rows;
@@ -311,6 +312,7 @@ static int curpos(void) {
     if (sscanf(buf + 2, "%d;%d", &rows, &cols) != 2) return -1;
     return cols;
 }
+#endif
 
 static int getcols(void) {
 #ifdef _WIN32