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-rwxr-xr-xC/Bra86.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/C/Bra86.c b/C/Bra86.c
new file mode 100755
index 0000000..93566cb
--- /dev/null
+++ b/C/Bra86.c
@@ -0,0 +1,85 @@
+/* Bra86.c -- Converter for x86 code (BCJ)
+2008-10-04 : Igor Pavlov : Public domain */
+
+#include "Bra.h"
+
+#define Test86MSByte(b) ((b) == 0 || (b) == 0xFF)
+
+const Byte kMaskToAllowedStatus[8] = {1, 1, 1, 0, 1, 0, 0, 0};
+const Byte kMaskToBitNumber[8] = {0, 1, 2, 2, 3, 3, 3, 3};
+
+SizeT x86_Convert(Byte *data, SizeT size, UInt32 ip, UInt32 *state, int encoding)
+{
+ SizeT bufferPos = 0, prevPosT;
+ UInt32 prevMask = *state & 0x7;
+ if (size < 5)
+ return 0;
+ ip += 5;
+ prevPosT = (SizeT)0 - 1;
+
+ for (;;)
+ {
+ Byte *p = data + bufferPos;
+ Byte *limit = data + size - 4;
+ for (; p < limit; p++)
+ if ((*p & 0xFE) == 0xE8)
+ break;
+ bufferPos = (SizeT)(p - data);
+ if (p >= limit)
+ break;
+ prevPosT = bufferPos - prevPosT;
+ if (prevPosT > 3)
+ prevMask = 0;
+ else
+ {
+ prevMask = (prevMask << ((int)prevPosT - 1)) & 0x7;
+ if (prevMask != 0)
+ {
+ Byte b = p[4 - kMaskToBitNumber[prevMask]];
+ if (!kMaskToAllowedStatus[prevMask] || Test86MSByte(b))
+ {
+ prevPosT = bufferPos;
+ prevMask = ((prevMask << 1) & 0x7) | 1;
+ bufferPos++;
+ continue;
+ }
+ }
+ }
+ prevPosT = bufferPos;
+
+ if (Test86MSByte(p[4]))
+ {
+ UInt32 src = ((UInt32)p[4] << 24) | ((UInt32)p[3] << 16) | ((UInt32)p[2] << 8) | ((UInt32)p[1]);
+ UInt32 dest;
+ for (;;)
+ {
+ Byte b;
+ int index;
+ if (encoding)
+ dest = (ip + (UInt32)bufferPos) + src;
+ else
+ dest = src - (ip + (UInt32)bufferPos);
+ if (prevMask == 0)
+ break;
+ index = kMaskToBitNumber[prevMask] * 8;
+ b = (Byte)(dest >> (24 - index));
+ if (!Test86MSByte(b))
+ break;
+ src = dest ^ ((1 << (32 - index)) - 1);
+ }
+ p[4] = (Byte)(~(((dest >> 24) & 1) - 1));
+ p[3] = (Byte)(dest >> 16);
+ p[2] = (Byte)(dest >> 8);
+ p[1] = (Byte)dest;
+ bufferPos += 5;
+ }
+ else
+ {
+ prevMask = ((prevMask << 1) & 0x7) | 1;
+ bufferPos++;
+ }
+ }
+ prevPosT = bufferPos - prevPosT;
+ *state = ((prevPosT > 3) ? 0 : ((prevMask << ((int)prevPosT - 1)) & 0x7));
+ return bufferPos;
+}