yetangitu/ghidra
1
0
Fork 0
mirror of https://github.com/NationalSecurityAgency/ghidra.git synced 2025-10-04 18:29:37 +02:00
Code Issues Releases Wiki Activity

Fixing some bugs in the new transform framework

Browse source
This commit is contained in:
caheckman 2020-03-16 10:24:43 -04:00
parent e4084b40ee
commit a8f9d4f7ac
3 changed files with 27 additions and 9 deletions
Download patch file Download diff file Expand all files Collapse all files

8
Ghidra/Features/Decompiler/src/decompile/cpp/subflow.cc
View file

@ -1807,16 +1807,12 @@ bool SubfloatFlow::traceForward(TransformVar *rvn)
{
TransformVar *rvn2 = setReplacement(op->getIn(1-slot));
if (rvn2 == (TransformVar *)0) return false;
if (preexistingGuard(slot, rvn2)) {
TransformOp *rop = newPreexistingOp(2, op->code(), op);
if (slot == 0) {
opSetInput(rop, rvn, 0);
opSetInput(rop, rvn2, 1);
}
else {
opSetInput(rop,rvn2,0);
opSetInput(rop,rvn,1);
}
terminatorCount += 1;
}
break;
}
case CPUI_FLOAT_TRUNC:

2
Ghidra/Features/Decompiler/src/decompile/cpp/transform.cc
View file

@ -226,6 +226,8 @@ void TransformOp::createReplacement(Funcdata *fd)
fd->opSetOpcode(op, opc);
while(input.size() < op->numInput())
fd->opRemoveInput(op, op->numInput()-1);
for(int4 i=0;i<op->numInput();++i)
fd->opUnsetInput(op,i); // Clear any remaining inputs
while(op->numInput() < input.size())
fd->opInsertInput(op, (Varnode *)0, op->numInput()-1);
}

20
Ghidra/Features/Decompiler/src/decompile/cpp/transform.hh
View file

@ -182,6 +182,7 @@ public:
TransformVar *getSplit(Varnode *vn,const LaneDescription &description,int4 numLanes,int4 startLane);
void opSetInput(TransformOp *rop,TransformVar *rvn,int4 slot); ///< Mark given variable as input to given op
void opSetOutput(TransformOp *rop,TransformVar *rvn); ///< Mark given variable as output of given op
static bool preexistingGuard(int4 slot,TransformVar *rvn); ///< Should newPreexistingOp be called
void apply(void); ///< Apply the full transform to the function
};
@ -226,4 +227,23 @@ inline void TransformManager::opSetOutput(TransformOp *rop,TransformVar *rvn)
rvn->def = rop;
}
/// Varnode marking prevents duplicate TransformOp (and TransformVar) records from getting
/// created, except in the case of a preexisting PcodeOp with 2 (or more) non-constant inputs.
/// Because the op is preexisting the output Varnode doesn't get marked, and the op will
/// be visited for each input. This method determines when the TransformOp object should be
/// created, with the goal of creating it exactly once even though the op is visited more than once.
/// It currently assumes the PcodeOp is binary, and the slot along which the op is
/// currently visited is passed in, along with the TransformVar for the \e other input. It returns
/// \b true if the TransformOp should be created.
/// \param slot is the incoming slot along which the op is visited
/// \param rvn is the other input
inline bool TransformManager::preexistingGuard(int4 slot,TransformVar *rvn)
{
if (slot == 0) return true; // If we came in on the first slot, build the TransformOp
if (rvn->type == TransformVar::piece || rvn->type == TransformVar::piece_temp)
return false; // The op was/will be visited on slot 0, don't create TransformOp now
return true; // The op was not (will not be) visited on slot 0, build now
}
#endif