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convert splitVarnode to transferVarnodeProperties

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This commit is contained in:
caheckman 2019-10-08 09:31:40 -04:00
parent 873294d1d8
commit bb0feb3d62
2 changed files with 12 additions and 24 deletions
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2
Ghidra/Features/Decompiler/src/decompile/cpp/funcdata.hh
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@ -352,7 +352,7 @@ public:
bool onlyOpUse(const Varnode *invn,const PcodeOp *opmatch,const ParamTrial &trial) const;
bool ancestorOpUse(int4 maxlevel,const Varnode *invn,const PcodeOp *op,ParamTrial &trial) const;
bool syncVarnodesWithSymbols(const ScopeLocal *lm,bool typesyes);
void splitVarnode(Varnode *vn,int4 lowsize,Varnode *&vnlo,Varnode *& vnhi);
void transferVarnodeProperties(Varnode *vn,Varnode *newVn,int4 lsbOffset);
bool fillinReadOnly(Varnode *vn); ///< Replace the given Varnode with its (constant) value in the load image
bool replaceVolatile(Varnode *vn); ///< Replace accesses of the given Varnode with \e volatile operations
void markIndirectOnly(void); ///< Mark \e illegal \e input Varnodes used only in INDIRECTs

34
Ghidra/Features/Decompiler/src/decompile/cpp/funcdata_varnode.cc
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@ -479,34 +479,22 @@ void Funcdata::setHighLevel(void)
assignHigh(*iter);
}
/// \brief Create two new Varnodes which split the given Varnode
/// \brief Copy properties from an existing Varnode to a new Varnode
///
/// Attributes are copied from the original into the split pieces if appropriate
/// \param vn is the given Varnode
/// \param lowsize is the desired size in bytes of the least significant portion
/// \param vnlo will hold the least significant portion
/// \param vnhi will hold the most significant portion
void Funcdata::splitVarnode(Varnode *vn,int4 lowsize,Varnode *& vnlo,Varnode *& vnhi)
/// The new Varnode is assumed to overlap the storage of the existing Varnode.
/// Properties like boolean flags and \e consume bits are copied as appropriate.
/// \param vn is the existing Varnode
/// \param newVn is the new Varnode that has its properties set
/// \param lsbOffset is the significance offset of the new Varnode within the exising
void Funcdata::transferVarnodeProperties(Varnode *vn,Varnode *newVn,int4 lsbOffset)
{
int4 highsize = vn->getSize() - lowsize;
Address addrhi = vn->getAddr();
Address addrlo = addrhi;
uintb consumehi = vn->getConsume() >> 8*lowsize;
uintb consumelo = vn->getConsume() & calc_mask(lowsize);
if (vn->getSpace()->isBigEndian())
addrlo = addrhi + highsize;
else
addrhi = addrhi + lowsize;
uintb newConsume = (vn->getConsume() >> 8*lsbOffset) & calc_mask(newVn->getSize());
uint4 vnflags = vn->getFlags() & (Varnode::directwrite|Varnode::addrforce|Varnode::auto_live);
vnhi = newVarnode(highsize,addrhi);
vnlo = newVarnode(lowsize,addrlo);
uint4 vnFlags = vn->getFlags() & (Varnode::directwrite|Varnode::addrforce|Varnode::auto_live);
vnhi->setFlags(vnflags); // Preserve addrforce setting
vnlo->setFlags(vnflags);
vnhi->setConsume(consumehi);
vnlo->setConsume(consumelo);
newVn->setFlags(vnFlags); // Preserve addrforce setting
newVn->setConsume(newConsume);
}
/// Treat the given Varnode as read-only, look up its value in LoadImage