added `bswap()` generic macro

the macro uses GCC builtins to guarantee generation of `bswap*` instructions.

Integer types are supported from u/i16 to u/i128

Fix bug in VERSION macro expansion with internal `#undef`"d macros.

Fortune for naka's current commit: Half blessing − 半吉

include/macros.h

@@ -71,22 +71,7 @@ _mixin void _drain_val(void* x, ...) { IGNORE(x); }
 
 // Function macros
 
-#define TRACEx(X, msg, ...) (fprintf(stderr, "[" X "] " __FILE__ ":%d->%s(): " msg "\n", __LINE__, __func__, ## __VA_ARGS__)) 
-
-#ifdef DEBUG
-#define TRACE(msg, ...) TRACEx("trace",   msg, ## __VA_ARGS__)
-#elif defined(_EVAL_DEBUG_ONLY_STMTS)
-#define TRACE(msg, ...) _drain(msg, ## __VA_ARGS__)
-#else
-#define TRACE(msg, ...) _no_op
-#endif
-#define INFO(msg, ...) TRACEx("info",  msg,  ## __VA_ARGS__)
-#define WARN(msg, ...) TRACEx("warning", msg, ## __VA_ARGS__)
-#define ERROR(msg, ...) TRACEx("error",  msg, ## __VA_ARGS__)
-
-#define FATAL(msg, ...) (TRACEx("FATAL",   msg, ## __VA_ARGS__), abort())
-
-// Assertion macros
+//  Assertions
 
 #ifdef DEBUG
 #define debug_assert(x) assert((x))
@@ -108,9 +93,52 @@ _mixin void _drain_val(void* x, ...) { IGNORE(x); }
 #define debug_static_assert(x, msg) _Static_assert(1, msg)
 #endif
 
+#define static_assert_eq(x,y,msg) _Static_assert((x) == (y), msg)
+#define static_assert_ne(x,y,msg) _Static_assert((x) != (y), msg)
+
+//  Bitmasking
+
+#define _BSWAP(x) __builtin_bswa  x
+#define BSWAP_16(x) _BSWAP(p16)  (AS((x), uint16_t))
+#define BSWAP_32(x) _BSWAP(p32)  (AS((x), uint32_t))
+#define BSWAP_64(x) _BSWAP(p64)  (AS((x), uint64_t))
+#define BSWAP_128(x) _BSWAP(p128)(AS((x), uint128_t))
+
+#undef _BSWAP
+#define _BSWAP(n) __builtin_bswap ## n
+
+#define bswap(x) _Generic((x), \
+		uint64_t: _BSWAP(64), int64_t: _BSWAP(64), \
+		uint32_t: _BSWAP(32), int32_t: _BSWAP(32), \
+		uint16_t: _BSWAP(16), int16_t: _BSWAP(16), \
+		__uint128_t: _BSWAP(128), __int128_t: _BSWAP(128)) \
+	((x))
+
+
+static_assert_eq(bswap(128lu), 9223372036854775808lu, "bswap128 (lu) failed (1)");
+static_assert_eq(128lu, bswap(9223372036854775808lu), "bswap128 (lu) failed (2)");
+static_assert_eq(bswap(bswap(128lu)), 128, "bswap128 (lu) failed (3)");
+
+//  Trace message output
+
+#define TRACEx(X, msg, ...) (fprintf(stderr, "[" X "] " __FILE__ ":%d->%s(): " msg "\n", __LINE__, __func__, ## __VA_ARGS__)) 
+
+#ifdef DEBUG
+#define TRACE(msg, ...) TRACEx("trace",   msg, ## __VA_ARGS__)
+#elif defined(_EVAL_DEBUG_ONLY_STMTS)
+#define TRACE(msg, ...) _drain(msg, ## __VA_ARGS__)
+#else
+#define TRACE(msg, ...) _no_op
+#endif
+#define INFO(msg, ...) TRACEx("info",  msg,  ## __VA_ARGS__)
+#define WARN(msg, ...) TRACEx("warning", msg, ## __VA_ARGS__)
+#define ERROR(msg, ...) TRACEx("error",  msg, ## __VA_ARGS__)
+
+#define FATAL(msg, ...) (TRACEx("FATAL",   msg, ## __VA_ARGS__), abort())
+
 // Version macros
 
-#define _UI(x) ((uint32_t)(x))
+#define _AS_u32(x) ((uint32_t)(x))
 
 #define VER_COMP_MAJ 24u
 #define VER_COMP_MIN 16u
@@ -118,19 +146,18 @@ _mixin void _drain_val(void* x, ...) { IGNORE(x); }
 #define VER_COMP_REV 0u
 
 /// Create a `uint32_t` from these version componants
-#define VERSION(maj,min,bf,rev) _UI( _UI(maj) << 24u | _UI(min) << 16u | _UI(bf) << 8u | _UI(rev) )
+#define VERSION(maj,min,bf,rev) _AS_u32( _AS_u32(maj) << 24u | _AS_u32(min) << 16u | _AS_u32(bf) << 8u | _AS_u32(rev) )
 
 /// Mask `ver` to retain only the version component specified by `mask`
 ///
 /// # Example
 /// `_Static_assert( (VERSION_COMP(VERSION(1,2,3,4), VER_COMP_MIN) >> VER_COMP_MIN) == 2u)`
-#define VERSION_COMP(ver, mask) _UI( _UI(ver) & (0xffu << _UI(mask)) /*>> _UI(mask)*/ )
+#define VERSION_COMP(ver, mask) _AS_u32( _AS_u32(ver) & (0xffu << _AS_u32(mask)) /*>> _AS_u32(mask)*/ )
 
-#define VERSION_MAJ(ver) _UI(VERSION_COMP((ver), 24u) >> 24u)
-#define VERSINO_MIN(ver) _UI(VERSION_COMP((ver), 16u) >> 16u)
-#define VERSINO_BF(ver)  _UI(VERSION_COMP((ver), 8u) >> 8u)
-#define VERSINO_REV(ver) _UI(_UI(ver) & 0xffu)
+#define VERSION_MAJ(ver) _AS_u32(VERSION_COMP((ver), 24u) >> 24u)
+#define VERSINO_MIN(ver) _AS_u32(VERSION_COMP((ver), 16u) >> 16u)
+#define VERSINO_BF(ver)  _AS_u32(VERSION_COMP((ver), 8u) >> 8u)
+#define VERSINO_REV(ver) _AS_u32(_AS_u32(ver) & 0xffu)
 _Static_assert( (VERSION_COMP(VERSION(1,2,3,4), VER_COMP_MIN) >> VER_COMP_MIN) == 2u, "invalid native version spec");
-#undef _UI
 
 #endif /* _MACROS_H */

src/main.c

@@ -12,7 +12,12 @@ int main(int argc, char** argv)
 	IGNORE(argc);
 	IGNORE(argv);
 
-	INFO("Hello world!");
+	u64 i = 128;
+
+	u32 vers = VERSION(1,2,3,4);
+
+	INFO("Hello world %lu %lu %lu!", i, bswap(i), bswap(bswap(i)));
+	//INFO("Version: 0x%x (0x%x)", vers, bswap(vers)); // Check which version endian was preferrable, we'll stick with the default system endian (little, for this one.)
 	return 0;
 }