1769b514d0
Disabled by default, used by loader and sbin/veriexec Reviewed by: emaste Sponsored by: Juniper Networks Differential Revision: D16334
98 lines
2.4 KiB
C#
98 lines
2.4 KiB
C#
/*
|
|
* Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining
|
|
* a copy of this software and associated documentation files (the
|
|
* "Software"), to deal in the Software without restriction, including
|
|
* without limitation the rights to use, copy, modify, merge, publish,
|
|
* distribute, sublicense, and/or sell copies of the Software, and to
|
|
* permit persons to whom the Software is furnished to do so, subject to
|
|
* the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be
|
|
* included in all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
|
|
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
|
|
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
|
|
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
* SOFTWARE.
|
|
*/
|
|
|
|
using System;
|
|
|
|
class TPointerExpr : TPointerBase {
|
|
|
|
string expr;
|
|
int min, max;
|
|
|
|
internal TPointerExpr(string expr, int min, int max)
|
|
{
|
|
this.expr = expr;
|
|
this.min = min;
|
|
this.max = max;
|
|
}
|
|
|
|
internal override bool ToBool(TValue vp)
|
|
{
|
|
throw new Exception("Cannot evaluate C-expr at compile time");
|
|
}
|
|
|
|
internal override string ToString(TValue vp)
|
|
{
|
|
return ToCExpr(vp.x);
|
|
}
|
|
|
|
internal string ToCExpr(int off)
|
|
{
|
|
if (off == 0) {
|
|
return expr;
|
|
} else if (off > 0) {
|
|
return String.Format(
|
|
"(uint32_t)({0}) + {1}", expr, off);
|
|
} else {
|
|
return String.Format(
|
|
"(uint32_t)({0}) - {1}", expr, -(long)off);
|
|
}
|
|
}
|
|
|
|
internal int GetMaxBitLength(int off)
|
|
{
|
|
long rmin = (long)min + off;
|
|
long rmax = (long)max + off;
|
|
int numBits = 1;
|
|
if (rmin < 0) {
|
|
numBits = Math.Max(numBits, BitLength(rmin));
|
|
}
|
|
if (rmax > 0) {
|
|
numBits = Math.Max(numBits, BitLength(rmax));
|
|
}
|
|
return Math.Min(numBits, 32);
|
|
}
|
|
|
|
/*
|
|
* Get the minimal bit length of a value. This is for a signed
|
|
* representation: the length includes a sign bit. Thus, the
|
|
* returned value will be at least 1.
|
|
*/
|
|
static int BitLength(long v)
|
|
{
|
|
int num = 1;
|
|
if (v < 0) {
|
|
while (v != -1) {
|
|
num ++;
|
|
v >>= 1;
|
|
}
|
|
} else {
|
|
while (v != 0) {
|
|
num ++;
|
|
v >>= 1;
|
|
}
|
|
}
|
|
return num;
|
|
}
|
|
}
|