--- /dev/null
+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
+ *
+ * Copyright (c) 2005 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+#ifndef __FILE_ABSTRACTION__
+#define __FILE_ABSTRACTION__
+
+
+#include <stdint.h>
+#include <string.h>
+#include <libkern/OSByteOrder.h>
+
+#ifdef __OPTIMIZE__
+#define INLINE __attribute__((always_inline))
+#else
+#define INLINE
+#endif
+
+//
+// This abstraction layer is for use with file formats that have 64-bit/32-bit and Big-Endian/Little-Endian variants
+//
+// For example: to make a utility that handles 32-bit little enidan files use: Pointer32<LittleEndian>
+//
+//
+// get16() read a 16-bit number from an E endian struct
+// set16() write a 16-bit number to an E endian struct
+// get32() read a 32-bit number from an E endian struct
+// set32() write a 32-bit number to an E endian struct
+// get64() read a 64-bit number from an E endian struct
+// set64() write a 64-bit number to an E endian struct
+//
+// getBits() read a bit field from an E endian struct (bitCount=number of bits in field, firstBit=bit index of field)
+// setBits() write a bit field to an E endian struct (bitCount=number of bits in field, firstBit=bit index of field)
+//
+// getBitsRaw() read a bit field from a struct with native endianness
+// setBitsRaw() write a bit field from a struct with native endianness
+//
+
+class BigEndian
+{
+public:
+ static uint16_t get16(const uint16_t& from) INLINE { return OSReadBigInt16(&from, 0); }
+ static void set16(uint16_t& into, uint16_t value) INLINE { OSWriteBigInt16(&into, 0, value); }
+
+ static uint32_t get32(const uint32_t& from) INLINE { return OSReadBigInt32(&from, 0); }
+ static void set32(uint32_t& into, uint32_t value) INLINE { OSWriteBigInt32(&into, 0, value); }
+
+ static uint64_t get64(const uint64_t& from) INLINE { return OSReadBigInt64(&from, 0); }
+ static void set64(uint64_t& into, uint64_t value) INLINE { OSWriteBigInt64(&into, 0, value); }
+
+ static uint32_t getBits(const uint32_t& from,
+ uint8_t firstBit, uint8_t bitCount) INLINE { return getBitsRaw(get32(from), firstBit, bitCount); }
+ static void setBits(uint32_t& into, uint32_t value,
+ uint8_t firstBit, uint8_t bitCount) INLINE { uint32_t temp = get32(into); setBitsRaw(temp, value, firstBit, bitCount); set32(into, temp); }
+
+ static uint32_t getBitsRaw(const uint32_t& from,
+ uint8_t firstBit, uint8_t bitCount) INLINE { return ((from >> (32-firstBit-bitCount)) & ((1<<bitCount)-1)); }
+ static void setBitsRaw(uint32_t& into, uint32_t value,
+ uint8_t firstBit, uint8_t bitCount) INLINE { uint32_t temp = into;
+ const uint32_t mask = ((1<<bitCount)-1);
+ temp &= ~(mask << (32-firstBit-bitCount));
+ temp |= ((value & mask) << (32-firstBit-bitCount));
+ into = temp; }
+ enum { little_endian = 0 };
+};
+
+
+class LittleEndian
+{
+public:
+ static uint16_t get16(const uint16_t& from) INLINE { return OSReadLittleInt16(&from, 0); }
+ static void set16(uint16_t& into, uint16_t value) INLINE { OSWriteLittleInt16(&into, 0, value); }
+
+ static uint32_t get32(const uint32_t& from) INLINE { return OSReadLittleInt32(&from, 0); }
+ static void set32(uint32_t& into, uint32_t value) INLINE { OSWriteLittleInt32(&into, 0, value); }
+
+ static uint64_t get64(const uint64_t& from) INLINE { return OSReadLittleInt64(&from, 0); }
+ static void set64(uint64_t& into, uint64_t value) INLINE { OSWriteLittleInt64(&into, 0, value); }
+
+ static uint32_t getBits(const uint32_t& from,
+ uint8_t firstBit, uint8_t bitCount) INLINE { return getBitsRaw(get32(from), firstBit, bitCount); }
+ static void setBits(uint32_t& into, uint32_t value,
+ uint8_t firstBit, uint8_t bitCount) INLINE { uint32_t temp = get32(into); setBitsRaw(temp, value, firstBit, bitCount); set32(into, temp); }
+
+ static uint32_t getBitsRaw(const uint32_t& from,
+ uint8_t firstBit, uint8_t bitCount) INLINE { return ((from >> firstBit) & ((1<<bitCount)-1)); }
+ static void setBitsRaw(uint32_t& into, uint32_t value,
+ uint8_t firstBit, uint8_t bitCount) INLINE { uint32_t temp = into;
+ const uint32_t mask = ((1<<bitCount)-1);
+ temp &= ~(mask << firstBit);
+ temp |= ((value & mask) << firstBit);
+ into = temp; }
+ enum { little_endian = 1 };
+};
+
+
+template <typename _E>
+class Pointer32
+{
+public:
+ typedef uint32_t uint_t;
+ typedef _E E;
+
+ static uint64_t getP(const uint_t& from) INLINE { return _E::get32(from); }
+ static void setP(uint_t& into, uint64_t value) INLINE { _E::set32(into, value); }
+};
+
+
+template <typename _E>
+class Pointer64
+{
+public:
+ typedef uint64_t uint_t;
+ typedef _E E;
+
+ static uint64_t getP(const uint_t& from) INLINE { return _E::get64(from); }
+ static void setP(uint_t& into, uint64_t value) INLINE { _E::set64(into, value); }
+};
+
+
+
+
+
+#endif // __FILE_ABSTRACTION__
+
+
projects / apple / ld64.git / blobdiff