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binpac: Bug fix of pac_swap function with int32 type of argument.

Browse source 
How to reproduce:

>>>code
int32 n = 0xF71B0000;
int32 n1 = pac_swap(n);
code<<<

n1 becomes 0xFFFFFFF7 instead of 0x00001BF7

Reason: Undefined behaviour after bit shift operation because of
negative value of the argument. See C++ standard (2011) 5.8.2 (Shift
operators).
This commit is contained in:
Bartolo Otrit 2016-06-04 16:08:05 +03:00 • committed by Tim Wojtulewicz
parent d73e3485c1
commit f1239143cb
1 changed files with 25 additions and 40 deletions
Download patch file Download diff file Expand all files Collapse all files

65
tools/binpac/lib/binpac.h.in
View file

@ -63,62 +63,47 @@ typedef const char *const_charptr;
namespace { namespace {
inline int16 pac_swap(int16 x) inline uint16 pac_swap(const uint16 x)
{ {
return (x >> 8) | ((x & 0xff) << 8); return (x >> 8) | ((x & 0xff) << 8);
} }
inline uint16 pac_swap(uint16 x) inline int16 pac_swap(const int16 x)
{ {
return (x >> 8) | ((x & 0xff) << 8); uint16 (*p)(const uint16) = &pac_swap;
return (*p)(x);
} }
inline int32 pac_swap(int32 x) inline uint32 pac_swap(const uint32 x)
{ {
return (x >> 24) | return (x >> 24) |
((x & 0xff0000) >> 8) | ((x & 0xff0000) >> 8) |
((x & 0xff00) << 8) | ((x & 0xff00) << 8) |
((x & 0xff) << 24); ((x & 0xff) << 24);
} }
inline uint32 pac_swap(uint32 x) inline int32 pac_swap(const int32 x)
{ {
return (x >> 24) | uint32 (*p)(const uint32) = &pac_swap;
((x & 0xff0000) >> 8) | return (*p)(x);
((x & 0xff00) << 8) |
((x & 0xff) << 24);
} }
inline int64 pac_swap(int64 i) inline uint64 pac_swap(const uint64 x)
{ {
unsigned char c; return x >> 56 |
union { (x & 0xff000000000000) >> 40 |
uint64 i; (x & 0xff0000000000) >> 24 |
unsigned char c[8]; (x & 0xff00000000) >> 8 |
} x; (x & 0xff000000) << 8 |
(x & 0xff0000) << 24 |
x.i = i; (x & 0xff00) << 40 |
c = x.c[0]; x.c[0] = x.c[7]; x.c[7] = c; (x & 0xff) << 56;
c = x.c[1]; x.c[1] = x.c[6]; x.c[6] = c;
c = x.c[2]; x.c[2] = x.c[5]; x.c[5] = c;
c = x.c[3]; x.c[3] = x.c[4]; x.c[4] = c;
return x.i;
} }
inline uint64 pac_swap(uint64 i) inline int64 pac_swap(const int64 x)
{ {
unsigned char c; uint64 (*p)(const uint64) = &pac_swap;
union { return (*p)(x);
uint64 i;
unsigned char c[8];
} x;
x.i = i;
c = x.c[0]; x.c[0] = x.c[7]; x.c[7] = c;
c = x.c[1]; x.c[1] = x.c[6]; x.c[6] = c;
c = x.c[2]; x.c[2] = x.c[5]; x.c[5] = c;
c = x.c[3]; x.c[3] = x.c[4]; x.c[4] = c;
return x.i;
} }
#define FixByteOrder(byteorder, x) (byteorder == HOST_BYTEORDER ? (x) : pac_swap(x)) #define FixByteOrder(byteorder, x) (byteorder == HOST_BYTEORDER ? (x) : pac_swap(x))