1 //===- llvm/Support/LEB128.h - [SU]LEB128 utility functions -----*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file declares some utility functions for encoding SLEB128 and
11 // ULEB128 values.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 /* Capstone Disassembly Engine */
16 /* By Nguyen Anh Quynh <aquynh@gmail.com>, 2013-2015 */
17 
18 #ifndef CS_LLVM_SUPPORT_LEB128_H
19 #define CS_LLVM_SUPPORT_LEB128_H
20 
21 #include "include/capstone/capstone.h"
22 
23 /// Utility function to decode a ULEB128 value.
decodeULEB128(const uint8_t * p,unsigned * n)24 static inline uint64_t decodeULEB128(const uint8_t *p, unsigned *n)
25 {
26 	const uint8_t *orig_p = p;
27 	uint64_t Value = 0;
28 	unsigned Shift = 0;
29 	do {
30 		Value += (uint64_t)(*p & 0x7f) << Shift;
31 		Shift += 7;
32 	} while (*p++ >= 128);
33 	if (n)
34 		*n = (unsigned)(p - orig_p);
35 	return Value;
36 }
37 
38 #endif  // LLVM_SYSTEM_LEB128_H
39