Cygwin: Allow cross-builds to non-Cygwin targets.

src/lj_alloc.c

@@ -194,7 +194,7 @@ static LJ_AINLINE void *CALL_MMAP(size_t size)
   return ptr;
 }
 
-#elif LJ_TARGET_OSX || LJ_TARGET_PS4 || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(__sun__) || defined(__CYGWIN__)
+#elif LJ_TARGET_OSX || LJ_TARGET_PS4 || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(__sun__) || LJ_TARGET_CYGWIN
 
 /* OSX and FreeBSD mmap() use a naive first-fit linear search.
 ** That's perfect for us. Except that -pagezero_size must be set for OSX,

src/lj_arch.h

@@ -70,7 +70,10 @@
        defined(__NetBSD__) || defined(__OpenBSD__) || \
        defined(__DragonFly__)) && !defined(__ORBIS__)
 #define LUAJIT_OS	LUAJIT_OS_BSD
-#elif (defined(__sun__) && defined(__svr4__)) || defined(__CYGWIN__)
+#elif (defined(__sun__) && defined(__svr4__))
+#define LUAJIT_OS	LUAJIT_OS_POSIX
+#elif defined(__CYGWIN__)
+#define LJ_TARGET_CYGWIN	1
 #define LUAJIT_OS	LUAJIT_OS_POSIX
 #else
 #define LUAJIT_OS	LUAJIT_OS_OTHER
@@ -133,7 +136,7 @@
 #define LJ_ARCH_NAME		"x86"
 #define LJ_ARCH_BITS		32
 #define LJ_ARCH_ENDIAN		LUAJIT_LE
-#if LJ_TARGET_WINDOWS || __CYGWIN__
+#if LJ_TARGET_WINDOWS || LJ_TARGET_CYGWIN
 #define LJ_ABI_WIN		1
 #else
 #define LJ_ABI_WIN		0
@@ -151,7 +154,7 @@
 #define LJ_ARCH_NAME		"x64"
 #define LJ_ARCH_BITS		64
 #define LJ_ARCH_ENDIAN		LUAJIT_LE
-#if LJ_TARGET_WINDOWS || __CYGWIN__
+#if LJ_TARGET_WINDOWS || LJ_TARGET_CYGWIN
 #define LJ_ABI_WIN		1
 #else
 #define LJ_ABI_WIN		0

src/lj_clib.c

@@ -39,7 +39,7 @@ LJ_NORET LJ_NOINLINE static void clib_error_(lua_State *L)
 
 #define clib_error(L, fmt, name)	clib_error_(L)
 
-#if defined(__CYGWIN__)
+#if LJ_TARGET_CYGWIN
 #define CLIB_SOPREFIX	"cyg"
 #else
 #define CLIB_SOPREFIX	"lib"
@@ -47,7 +47,7 @@ LJ_NORET LJ_NOINLINE static void clib_error_(lua_State *L)
 
 #if LJ_TARGET_OSX
 #define CLIB_SOEXT	"%s.dylib"
-#elif defined(__CYGWIN__)
+#elif LJ_TARGET_CYGWIN
 #define CLIB_SOEXT	"%s.dll"
 #else
 #define CLIB_SOEXT	"%s.so"
@@ -56,14 +56,14 @@ LJ_NORET LJ_NOINLINE static void clib_error_(lua_State *L)
 static const char *clib_extname(lua_State *L, const char *name)
 {
   if (!strchr(name, '/')
-#ifdef __CYGWIN__
+#if LJ_TARGET_CYGWIN
       && !strchr(name, '\\')
 #endif
      ) {
     if (!strchr(name, '.')) {
       name = lj_str_pushf(L, CLIB_SOEXT, name);
       L->top--;
-#ifdef __CYGWIN__
+#if LJ_TARGET_CYGWIN
     } else {
       return name;
 #endif