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Code Issues Releases Wiki Activity

Use context when determining if extension casts are hidden

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This commit is contained in:
caheckman 2020-02-20 14:05:55 -05:00
parent 163fa4af57
commit 36aebc2d9b
6 changed files with 117 additions and 115 deletions
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71
Ghidra/Features/Decompiler/src/decompile/cpp/printc.cc
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@ -591,11 +591,11 @@ void PrintC::opReturn(const PcodeOp *op)
pushAtom(Atom("",blanktoken,EmitXml::no_color));
}
void PrintC::opIntZext(const PcodeOp *op)
void PrintC::opIntZext(const PcodeOp *op,const PcodeOp *readOp)
{
if (castStrategy->isZextCast(op->getOut()->getHigh()->getType(),op->getIn(0)->getHigh()->getType())) {
if (isExtensionCastImplied(op))
if (isExtensionCastImplied(op,readOp))
opHiddenFunc(op);
else
opTypeCast(op);
@ -604,11 +604,11 @@ void PrintC::opIntZext(const PcodeOp *op)
opFunc(op);
}
void PrintC::opIntSext(const PcodeOp *op)
void PrintC::opIntSext(const PcodeOp *op,const PcodeOp *readOp)
{
if (castStrategy->isSextCast(op->getOut()->getHigh()->getType(),op->getIn(0)->getHigh()->getType())) {
if (isExtensionCastImplied(op))
if (isExtensionCastImplied(op,readOp))
opHiddenFunc(op);
else
opTypeCast(op);
@ -1288,8 +1288,9 @@ bool PrintC::printCharacterConstant(ostream &s,const Address &addr,int4 charsize
/// Sometimes such a cast is implied by the expression its in, and the cast itself
/// doesn't need to be printed.
/// \param op is the given ZEXT or SEXT PcodeOp
/// \param readOp is the PcodeOp consuming the output of the extensions (or null)
/// \return \b true if the op as a cast does not need to be printed
bool PrintC::isExtensionCastImplied(const PcodeOp *op) const
bool PrintC::isExtensionCastImplied(const PcodeOp *op,const PcodeOp *readOp) const
{
if (!option_hide_exts)
@ -1299,37 +1300,37 @@ bool PrintC::isExtensionCastImplied(const PcodeOp *op) const
}
else {
if (readOp == (PcodeOp *) 0)
return false;
type_metatype metatype = outVn->getHigh()->getType()->getMetatype();
list<PcodeOp *>::const_iterator iter;
for(iter=outVn->beginDescend();iter!=outVn->endDescend();++iter) {
PcodeOp *expOp = *iter;
Varnode *otherVn;
int4 slot;
switch(expOp->code()) {
case CPUI_PTRADD:
break;
case CPUI_INT_ADD:
case CPUI_INT_SUB:
case CPUI_INT_MULT:
case CPUI_INT_DIV:
case CPUI_INT_AND:
case CPUI_INT_OR:
case CPUI_INT_XOR:
case CPUI_INT_LESS:
case CPUI_INT_LESSEQUAL:
case CPUI_INT_SLESS:
case CPUI_INT_SLESSEQUAL:
slot = expOp->getSlot(outVn);
otherVn = expOp->getIn(1-slot);
// Check if the expression involves an explicit variable of the right integer type
if (!otherVn->isExplicit())
return false;
if (otherVn->getHigh()->getType()->getMetatype() != metatype)
return false;
break;
default:
const Varnode *otherVn;
int4 slot;
switch (readOp->code()) {
case CPUI_PTRADD:
break;
case CPUI_INT_ADD:
case CPUI_INT_SUB:
case CPUI_INT_MULT:
case CPUI_INT_DIV:
case CPUI_INT_AND:
case CPUI_INT_OR:
case CPUI_INT_XOR:
case CPUI_INT_EQUAL:
case CPUI_INT_NOTEQUAL:
case CPUI_INT_LESS:
case CPUI_INT_LESSEQUAL:
case CPUI_INT_SLESS:
case CPUI_INT_SLESSEQUAL:
slot = readOp->getSlot(outVn);
otherVn = readOp->getIn(1 - slot);
// Check if the expression involves an explicit variable of the right integer type
if (!otherVn->isExplicit() && !otherVn->isConstant())
return false;
}
if (otherVn->getHigh()->getType()->getMetatype() != metatype)
return false;
break;
default:
return false;
}
return true; // Everything is integer promotion
}
@ -2153,7 +2154,7 @@ void PrintC::emitExpression(const PcodeOp *op)
// If BRANCHIND, print switch( )
// If CALL, CALLIND, CALLOTHER print call
// If RETURN, print return ( )
op->push(this);
op->getOpcode()->push(this,op,(PcodeOp *)0);
recurse();
}