yetangitu/ghidra
1
0
Fork 0
mirror of https://github.com/NationalSecurityAgency/ghidra.git synced 2025-10-03 17:59:46 +02:00
Code Issues Releases Wiki Activity

GP-5240 Simplify late expressions where a SUBPIECE is taken of a PIECE

Browse source
This commit is contained in:
caheckman 2025-01-06 21:51:28 +00:00
parent acf5ac688a
commit 53d8d182e3
15 changed files with 215 additions and 88 deletions
Download patch file Download diff file Expand all files Collapse all files

57
Ghidra/Features/Decompiler/src/decompile/cpp/cast.cc
View file

@ -4,9 +4,9 @@
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*
* http://www.apache.org/licenses/LICENSE-2.0
*
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@ -46,13 +46,14 @@ bool CastStrategy::markExplicitUnsigned(PcodeOp *op,int4 slot) const
if (!vn->isConstant()) return false;
Datatype *dt = vn->getHighTypeReadFacing(op);
type_metatype meta = dt->getMetatype();
if ((meta != TYPE_UINT)&&(meta != TYPE_UNKNOWN)) return false;
if (meta != TYPE_UINT && meta != TYPE_UNKNOWN && meta != TYPE_PARTIALSTRUCT && meta != TYPE_PARTIALUNION)
return false;
if (dt->isCharPrint()) return false;
if (dt->isEnumType()) return false;
if ((op->numInput() == 2) && !inheritsFirstParamOnly) {
Varnode *firstvn = op->getIn(1-slot);
meta = firstvn->getHighTypeReadFacing(op)->getMetatype();
if ((meta == TYPE_UINT)||(meta == TYPE_UNKNOWN))
if (meta == TYPE_UINT || meta == TYPE_UNKNOWN || meta == TYPE_PARTIALSTRUCT || meta == TYPE_PARTIALUNION)
return false; // Other side of the operation will force the unsigned
}
// Check if type is going to get forced anyway
@ -85,7 +86,9 @@ bool CastStrategy::markExplicitLongSize(PcodeOp *op,int4 slot) const
if (vn->getSize() <= promoteSize) return false;
Datatype *dt = vn->getHigh()->getType();
type_metatype meta = dt->getMetatype();
if ((meta != TYPE_UINT)&&(meta != TYPE_INT)&&(meta != TYPE_UNKNOWN)) return false;
if (meta != TYPE_UINT && meta != TYPE_INT && meta != TYPE_UNKNOWN &&
meta != TYPE_PARTIALSTRUCT && meta != TYPE_PARTIALUNION)
return false;
uintb off = vn->getOffset();
if (meta == TYPE_INT && signbit_negative(off, vn->getSize())) {
off = uintb_negate(off, vn->getSize());
@ -138,8 +141,9 @@ int4 CastStrategyC::localExtensionType(const Varnode *vn,const PcodeOp *op) cons
{
type_metatype meta = vn->getHighTypeReadFacing(op)->getMetatype();
int4 natural; // 1= natural zero extension, 2= natural sign extension
if ((meta == TYPE_UINT)||(meta == TYPE_BOOL)||(meta == TYPE_UNKNOWN))
int4 natural;
if (meta == TYPE_UINT || meta == TYPE_BOOL || meta == TYPE_UNKNOWN ||
meta == TYPE_PARTIALSTRUCT || meta == TYPE_PARTIALUNION)
natural = UNSIGNED_EXTENSION;
else if (meta == TYPE_INT)
natural = SIGNED_EXTENSION;
@ -331,20 +335,23 @@ Datatype *CastStrategyC::castStandard(Datatype *reqtype,Datatype *curtype,
}
switch(reqbase->getMetatype()) {
case TYPE_UNKNOWN:
case TYPE_PARTIALSTRUCT: // As they are ultimately stripped, treat partials as undefined
case TYPE_PARTIALUNION:
return (Datatype *)0;
case TYPE_UINT:
if (!care_uint_int) {
type_metatype meta = curbase->getMetatype();
// Note: meta can be TYPE_UINT if curbase is typedef/enumerated
if ((meta==TYPE_UNKNOWN)||(meta==TYPE_INT)||(meta==TYPE_UINT)||(meta==TYPE_BOOL))
if (meta==TYPE_UNKNOWN || meta==TYPE_INT || meta==TYPE_UINT || meta==TYPE_BOOL ||
meta==TYPE_PARTIALSTRUCT || meta==TYPE_PARTIALUNION)
return (Datatype *)0;
}
else {
type_metatype meta = curbase->getMetatype();
if ((meta == TYPE_UINT)||(meta==TYPE_BOOL)) // Can be TYPE_UINT for typedef/enumerated
return (Datatype *)0;
if (isptr && (meta==TYPE_UNKNOWN)) // Don't cast pointers to unknown
return (Datatype *)0;
if (isptr && (meta==TYPE_UNKNOWN || meta==TYPE_PARTIALSTRUCT || meta==TYPE_PARTIALUNION))
return (Datatype *)0; // Don't cast pointers to unknown
}
if ((!care_ptr_uint)&&(curbase->getMetatype()==TYPE_PTR))
return (Datatype *)0;
@ -353,15 +360,16 @@ Datatype *CastStrategyC::castStandard(Datatype *reqtype,Datatype *curtype,
if (!care_uint_int) {
type_metatype meta = curbase->getMetatype();
// Note: meta can be TYPE_INT if curbase is an enumerated type
if ((meta==TYPE_UNKNOWN)||(meta==TYPE_INT)||(meta==TYPE_UINT)||(meta==TYPE_BOOL))
if (meta==TYPE_UNKNOWN || meta==TYPE_INT || meta==TYPE_UINT || meta==TYPE_BOOL ||
meta==TYPE_PARTIALSTRUCT || meta==TYPE_PARTIALUNION)
return (Datatype *)0;
}
else {
type_metatype meta = curbase->getMetatype();
if ((meta == TYPE_INT)||(meta == TYPE_BOOL))
return (Datatype *)0; // Can be TYPE_INT for typedef/enumerated/char
if (isptr && (meta==TYPE_UNKNOWN)) // Don't cast pointers to unknown
return (Datatype *)0;
if (isptr && (meta==TYPE_UNKNOWN || meta==TYPE_PARTIALSTRUCT || meta==TYPE_PARTIALUNION))
return (Datatype *)0; // Don't cast pointers to unknown
}
break;
case TYPE_CODE:
@ -402,24 +410,19 @@ bool CastStrategyC::isSubpieceCast(Datatype *outtype,Datatype *intype,uint4 offs
{
if (offset != 0) return false;
type_metatype inmeta = intype->getMetatype();
if ((inmeta!=TYPE_INT)&&
(inmeta!=TYPE_UINT)&&
(inmeta!=TYPE_UNKNOWN)&&
(inmeta!=TYPE_PTR))
if (inmeta!=TYPE_INT && inmeta!=TYPE_UINT && inmeta!=TYPE_UNKNOWN && inmeta!=TYPE_PTR &&
inmeta!=TYPE_PARTIALSTRUCT && inmeta!=TYPE_PARTIALUNION)
return false;
type_metatype outmeta = outtype->getMetatype();
if ((outmeta!=TYPE_INT)&&
(outmeta!=TYPE_UINT)&&
(outmeta!=TYPE_UNKNOWN)&&
(outmeta!=TYPE_PTR)&&
(outmeta!=TYPE_FLOAT))
if (outmeta!=TYPE_INT && outmeta!=TYPE_UINT && outmeta!=TYPE_UNKNOWN &&
outmeta!=TYPE_PTR && outmeta!=TYPE_FLOAT)
return false;
if (inmeta==TYPE_PTR) {
if (outmeta == TYPE_PTR) {
if (outtype->getSize() < intype->getSize())
return true; // Cast from far pointer to near pointer
}
if ((outmeta!=TYPE_INT) && (outmeta!=TYPE_UINT))
if (outmeta!=TYPE_INT && outmeta!=TYPE_UINT)
return false; //other casts don't make sense for pointers
}
return true;
@ -477,12 +480,15 @@ Datatype *CastStrategyJava::castStandard(Datatype *reqtype,Datatype *curtype,
if (reqbase->getSize() != curbase->getSize()) return reqtype; // Always cast change in size
switch(reqbase->getMetatype()) {
case TYPE_UNKNOWN:
case TYPE_PARTIALSTRUCT: // As they are ultimately stripped, treat partials as undefined
case TYPE_PARTIALUNION:
return (Datatype *)0;
case TYPE_UINT:
if (!care_uint_int) {
type_metatype meta = curbase->getMetatype();
// Note: meta can be TYPE_UINT if curbase is typedef/enumerated
if ((meta==TYPE_UNKNOWN)||(meta==TYPE_INT)||(meta==TYPE_UINT)||(meta==TYPE_BOOL))
if (meta==TYPE_UNKNOWN || meta==TYPE_INT || meta==TYPE_UINT || meta==TYPE_BOOL ||
meta==TYPE_PARTIALSTRUCT || meta==TYPE_PARTIALUNION)
return (Datatype *)0;
}
else {
@ -495,7 +501,8 @@ Datatype *CastStrategyJava::castStandard(Datatype *reqtype,Datatype *curtype,
if (!care_uint_int) {
type_metatype meta = curbase->getMetatype();
// Note: meta can be TYPE_INT if curbase is an enumerated type
if ((meta==TYPE_UNKNOWN)||(meta==TYPE_INT)||(meta==TYPE_UINT)||(meta==TYPE_BOOL))
if (meta==TYPE_UNKNOWN || meta==TYPE_INT || meta==TYPE_UINT || meta==TYPE_BOOL ||
meta==TYPE_PARTIALSTRUCT || meta==TYPE_PARTIALUNION)
return (Datatype *)0;
}
else {