medfall

commit c3d3144e9c77e720583619ecc9087549eb3f3883
parent 296d2ef944256a47e8e89ea21c8c9b6077aa4230
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Sun Oct 16 20:40:38 +0300

Use runtime endianness checking

Diffstat:
intrinsics.h
 | 
7
+++++++
platform_atomic.h
 | 
6
------
platform_endian.h
 | 
18
------------------
stream.h
 | 
38
+++++++++++++-------------------------
4 files changed, 20 insertions(+), 49 deletions(-)
diff --git a/intrinsics.h b/intrinsics.h
@@ -116,6 +116,13 @@ inline void mike_assert( const bool predicate, const char * message ) {
 #define CONCAT( a, b ) CONCAT_HELPER( a, b )
 
 #define assert( predicate ) mike_assert( predicate, "\x1b[1;31massertion failed at " __FILE__ " line " STRINGIFY( __LINE__ ) ": \x1b[0;1m" #predicate "\x1b[0m" )
+#define ASSERT assert
+
+#if __cplusplus < 201103L
+#define STATIC_ASSERT( p ) static int CONCAT( STATIC_ASSERT, __COUNTER__ )[ int( p ) - 1 ]
+#else
+#define STATIC_ASSERT( p ) static_assert( p )
+#endif
 
 // TODO: this sucks
 inline u8 * file_get_contents( const char * path, size_t * out_len = NULL ) {
diff --git a/platform_atomic.h b/platform_atomic.h
@@ -118,11 +118,5 @@ struct atomic_u64 {
 #define exchange_seqcst( atom, x ) ( atom )->exchange( x, std::memory_order_seq_cst )
 #define compare_exchange_seqcst( atom, before, after ) ( atom )->compare_exchange_strong( *( before ), after, std::memory_order_seq_cst, std::memory_order_seq_cst )
 
-// relacy requires C++98 which doesn't have static_assert
-// TODO: maybe this should go somewhere else?
-#if __cplusplus < 201103L
-#define static_assert( p ) static int CONCAT( static_assert, __COUNTER__ )[ int( p ) - 1 ]
-#endif
-
 #endif // RL_TEST
 #endif // _PLATFORM_ATOMIC_H_
diff --git a/platform_endian.h b/platform_endian.h
@@ -1,18 +0,0 @@
-#ifndef _PLATFORM_ENDIAN_H_
-#define _PLATFORM_ENDIAN_H_
-
-#if defined( __linux__) || defined( __APPLE__ ) || defined( __OpenBSD__ )
-#  if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-#    define PLATFORM_LITTLE_ENDIAN 1
-#  elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-#    define PLATFORM_BIG_ENDIAN 1
-#  else
-#    error "I can't tell what byte order this machine uses"
-#  endif
-#elif defined( _WIN32 )
-#  define PLATFORM_LITTLE_ENDIAN 1
-#else
-#  error new platform
-#endif
-
-#endif // _PLATFORM_ENDIAN_H_
diff --git a/stream.h b/stream.h
@@ -2,49 +2,37 @@
 #define _STREAM_H_
 
 #include "intrinsics.h"
-#include "platform_endian.h"
 
 struct Stream {
 	char * ptr;
 };
 
-#if PLATFORM_LITTLE_ENDIAN
+bool cpu_is_little_endian() {
+#if FORCE_LITTLE_ENDIAN
+	return true;
+#else
+	u16 i = 1;
+	char * c = ( char * ) &i;
+	return c[ 0 ] == 1;
+#endif
+}
 
+// TODO: https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html
+// maybe use __builtin_bswap16/32/64 and http://stackoverflow.com/a/13208789
 #define DEF_READ_WRITE( type ) \
 	inline Stream read_##type( Stream stream, type * v ) { \
+		ASSERT( cpu_is_little_endian() ); \
 		*v = *( type * ) stream.ptr; \
 		stream.ptr += sizeof( type ); \
 		return stream; \
 	} \
 	inline Stream write_##type( Stream stream, const type * v ) { \
+		ASSERT( cpu_is_little_endian() ); \
 		*( type * ) stream.ptr = *v; \
 		stream.ptr += sizeof( type ); \
 		return stream; \
 	}
 
-#elif PLATFORM_BIG_ENDIAN
-
-#define DEF_READ_WRITE( type ) \
-	inline Stream read_##type( Stream stream, type * v ) { \
-		char swapped[ sizeof( type ) ]; \
-		for( int i = 0; i < sizeof( type ); i++ ) { \
-			swapped[ i ] = stream.ptr[ sizeof( swapped ) - 1 - i ]; \
-		} \
-		*v = *( type * ) swapped; \
-		stream.ptr += sizeof( type ); \
-		return stream; \
-	} \
-	inline Stream write_##type( Stream stream, const type * v ) { \
-		char * v_as_string = ( char * ) v; \
-		for( int i = 0; i < sizeof( type ); i++ ) { \
-			stream.ptr[ i ] = v_as_string[ sizeof( type ) - 1 - i ]; \
-		} \
-		stream.ptr += sizeof( type ); \
-		return stream; \
-	}
-
-#endif
-
 DEF_READ_WRITE( u8 )
 DEF_READ_WRITE( u16 )
 DEF_READ_WRITE( u32 )